The QualityCompany –Worldwide

HUBER Industry Report

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Contents

Industrial Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Industrial HUBER Solution for the meat processing industry–In record time from pilot testing to start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

HUBER Solution for Europe’s largest slaughterhouse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Complete wastewater treatment with a HUBER membrane bio-reactorprocess at GZM Extraktionswerk AG, Lyss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

HUBER - the competent partner of the meat industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Washwater recycling for Emirates Airlines in Dubai . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

ROTAMAT® Screw Press RoS 3 prevails all over the worldin the paper industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Application of HUBER equipment in plants for energy recoveryfrom biomass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Coarse solids and grit removal in organic waste fermentation plants -the beginning of a success story . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Use of heat from biogas cogeneration for sludge drying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Sucessful solid/liquid-separation and sludge dewateringof landfill leachate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Successful pilot testing at the Swiss nuclear power station Gösgenfor process water purification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

New application of the ROTAMAT® disk thickener RoS 2Sin the chemical industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Bamberger Kaliko –A model for wastewater recycling in the textile industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

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Industrial Solutions

You, our industrial customer, are generating yourprofits by manufacturing and selling products, or bygenerating energy, e.g. from biomass. Treatment ofthe by-products wastewater and sludge is not partof your “core business”. But you know thatprotection of our environment must be a part of yourholistic corporate philosophy.You are looking for a partner who, in cooperationwith you, develops and implements economicalsolutions for your wastewater treatment and wastedisposal.We understand !HANS HUBER AG is one of very few companiesworldwide offering not only a complete range ofprocess technologies for the treatment ofwastewater and process water, but also for sludgetreatment. We have the capability to designcomplete process chains by combining andintegrating various HUBER products, in other words:we offer comlete solutions and, of course, we takeresponsibility for their function. However, waste-water treatment alone is not enough. The next stepis: Closing the Loop!

Generation of high-quality process water for yourproduction from treated wastewater allows you tosave freshwater costs and wastewater fees.Do not overlook any material flow - not even yoursludge! Sludge treatment and reuse is an aspectthat must be taken into consideration for all holisticsolutions. Inexpensive waste disposal and, wherepossible, energy recovery from waste are ourobjectives.You see, there are many possibilies how we can turnyour “expensive wastewater project” into a costsaving water and waste recycling project.Our team includes several industry sector expertswho gained their experience from successful projectwork. They will be happy to share their knowledgeand experience with you.Let us help you to develop your project!

Ralph TeckenbergDirectorBusiness Unit Industrial Solutionstr@huber.de

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Industrial HUBER Solution for the Meat Processing Industry -In Record Time from Pilot Testing to Start-up

In 2006 we performed tests with a state-of-the-artpilot plant for wastewater treatment at theHeilsbronn factory of Hans Kupfer & Sohn GmbH &Co. KG, one of the largest meat processors inGermany. The capacity of their existing wastewatertreatment plant with SBR reactors had been farexceeded. Their consulting engineer, Dr. Resch inWeißenburg/Bavaria, had investigated the siteconditions and recommended pilot testing of amembrane bio-reactor process with a VRM®-membrane filter in cooperation with the HANSHUBER AG.

During the six months testing period we operated acomplete parallel wastewater treatment system,consisting of a screen, a dissolved air flotation plantHUBER HDF and a membrane bio-reactor HUBERVRM®. The necessary sampling and analysis was

done by a HUBER employed university graduand andMr. Scheuring, the chief operator of the Kupferwastewater treatment plant. The results wereevaluated by HUBER experts in close cooperationwith the consulting engineers Dr. Resch.After a serious fire had destroyed parts of the Kupferfactory, their management instantly decided torebuild a new and enlarged factory. This requiredfast design of the new wastewater treatment plant,based on the data that we had gained and evaluatedduring our pilot testing. The management of Kupferhad set the ambitious goal to start-up the rebuiltfactory by the end of 2007 or early in 2008.We were able to convince the Kupfer management ofour proposed complete solution and of the highquality of its components, not least because of ourexcellent performance during our pilot testing. On

Membrane bio-reactor with HUBER VRM® membrane filter during filling of the filter chamber

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the basis of the outline planning by Dr. Resch, wecould begin our detailed engineering work and themanufacturing of our components. Our supplyincluded new screens (a pair of RakeMax® multi-rakebar screens and a pair of ROTAMAT® Ro 2 ultra-finerotary screens with high-pressure spray bars), aHUBER HDF dissolved air flotation plant, threeparallel HUBER VRM® membrane filters and aROTAMAT® RoS 2S disc thickener for the sludge.The plant treats a wastewater flow of up to 1,600m³/d. After mechanical, chemo-physical andbiological treatment the permeate effluent is crystalclear and disinfected. The produced sludge (flotateand waste activated sludge) is thickened in our discthickener, then stored in a tank and finally hauledwith tanker vehicles to a biogas plant.In December 2007 our service engineers beganstarting up the new treatment plant and ourequipment . After the new factory had begunproduction in January 2008 and when sufficientwastewater arrived at the plant, we could also startup the new membrane bio-reactors. It went all verywell and without problems - after a short time thestringent effluent standards were met andexceeded. Since its commissioning the plant hasbeen operating very stable and reliably.The quality of the effluent is so good that it is reusedin the factory as secondary process water for steamgeneration. This water recycling saves our customersubstantial freshwater costs and improves the cost-efficiency of his wastewater treatment even further.Our excellent cooperation with the customer and hisconsulting engineer during pilot testing, design,installation and start-up led to an outstanding result,that was even new for us: beyond the originally

agreed HUBER service contract the customerwanted to employ our service engineer, Mr Schober,for further operational assistance and plantoptimization. Without interruption he proceededfrom his start-up job to a full-time operator job. Forseveral months he operated the plant almost aroundthe clock, even during week-ends. He could do thisvia the installed remote monitoring and controlsystem for every component, pump, automaticvalve and instrument. The required sample taking,analysis and interpretation were part of our contractand done in cooperation with Dr. Resch.We could readily realize all possibilities of plantoptimization. Of course, such a long presence andassistance by an expert helped our customer tobecome familiar with the operation of his plant andequipment. A very important additional benefit fromusing the experience of our service engineers is theopportunity to laern how to reduce operation costs,for example by optimization of the consuption ofpower and chemicals. We are more than happy toassist our customers in this way.

Thomas PohlersProject ManagerBusiness Unit Industrial Solutionspt@huber.de

Ultra-fine rotary screens ROTAMAT® Ro 2 (left) anddissolved air flotation plant HUBER HDF (right)

ROTAMAT® disc thickener RoS 2S

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HUBER Solution for Europe’s Largest Slaughterhouse

Europe’s largest slaughterhouse, with acapacity to slaughter up to 77,000 pigs peryear, was built by Danish Crown in Horsens,Denmark. This slaughterhouse was providedwith the latest slaughtering, butchering andpackaging equipment. Highest qualityequipment was also selected for its wastewaterand sludge treatment. HUBER supplied not onlythe equipment, but provided a completeprocess solution, including mechanical andchemo-physical wastewater treatment anddewatering of the generated sludge.In Europe’s largest and most modern slaughterhousein Horsens, Denmark, built and operated by theDanish Crown company, you can find not only thelatest technology for slaughtering and meat packing,but also a state-of-the-art HUBER solution forwastewater treatment with mechanical and chemo-physical process steps.

Danish Crown selected a HUBER solution for theirwastewater treatment because our equipment isknown for its robustness, reliability and excellentpeformance. The customer was impressed becausewe offered him a complete solution including allnecessary processes, screening and physico-chemicaltreatment of the wastewater, and also treatment ofthe generated sludge. The main objective was tomeet the consent standards permitting discharge ofthe wastewater into the municipal sewer system, butequally important for our customer was the reliability,durability, performance and cost-efficiency of ourequipment.

At the slaughterhouse in Horsens, three types ofwastewater streams are separately collected. It wasagreed to pre-treat each stream separately :

➤ Stream 1 is generated in the meat packaging andfreezing department. Its maximum flow is 35 l/s.

➤ Stream 2 arrives from the slaughterhouse andbutchery. The peak flow is 94 l/s.

➤ Stream 3 comes from the washing station of thelivestock vehicles. The maximum flow is 15 l/s.

Each wastewater stream is separately pre-treated byscreening. Each screen was selected and technicallyadapted to the particular flow and wastewatercomposition:

➤ Wastewater stream 1, arriving from the packingand freezing department, is screened through arotary wedge wire screen ROTAMAT® Ro 2 with a 1mm wedge wire spacing and a 780 mm diameterscreen basket. Its main task is removal of paperfrom wrappings and wood chips from pallets.

➤ Wastewater stream 2, generated in theslaughterhouse and butchery, is more difficult toscreen because it contains much fat and grease,pieces of meat and bristles. Even butcher hookscan be found in this stream. Robust and wellcleansable screens are therefore required for thisstream. We again selected rotary wedge wirescreens ROTAMAT® Ro 2 with a 1 mm spacing, butprovided them with additional spray bars foroptional back-washing with hot water to improveremoval of fat and grease. The diameter of thescreen baskets is 1,000 mm. To provide forsufficient redundancy during maintenance work,we supplied three (2 + 1) units. While one screenis shut down for service and maintenance, theremaining two screens can still easily handle thepeak flow.

➤ Wastewater stream 3, collected at the washingstation for the livestock trucks, contains highloads of solids, mainly consisting of hay and sawdust. For pre-screening we selected a pair ofscrew-type fine screens ROTAMAT® Ro 9 with a 3mm perforation and a screen basket diameter of700 mm. Downstream of each Ro 9 unit, a rotarywedge wire screen ROTAMAT® Ro 2 with a wedgewire spacing of 1 mm and a basket diameter of780 mm is installed. We chose this taperedscreening to combine the capability of the Ro 9 toremove high solids freights with the excellentcapture rate of the Ro 2.

After passage of the screens, all three wastewaterstreams enter a common balancing and storage tankwith a volume of 800 m³. This tank serves forreduction of hydraulic and freight peaks. The blendedand equalized wastewater is then pumped to threedissolved air flotation (DAF) plants HUBER HDF Size 7.Each of the three units has a capacity of 80 m³/h. Twoof the units are sufficient to process the entire flow,the third unit serves for redundancy. In this way wemaximize the reliability of operation. The operation of

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Three dissolved air flotation plants HUBER HDF Size7 with chemical pre-treatment in tubular reactors

the slaughterhouse remains unaffected when oneDAF unit is shut down for service and maintenancework.

Before the wastewater enters a DAF unit, FeCl3 isadded as coagulant and polymer as flocculant.Emulgated fats, blood and colloidal particles are thusdestabilized and flocculated, and can be removed inthe DAF plants. These chemicals are added atvariable points along the lenght of a tubular reactorwith a nominal diameter of 150 mm. The tubularreactor is designed and dimensioned such that thechemicals are quickly mixed into a turbulent flow andthat sufficiet retention time for good and strongflocculation is guaranteed.

An important requirement by our customer was goodtreatment and easy disposal of the generated flotatesludge. We supplied screw presses ROTAMAT® RoS 3for sludge dewatering. Main advantages of our screwpresses are that they are entirely enclosed, but easyand inexpensive to operate and maintain.Backwashing of their screen baskets is fullyautomated and requires very little washwater, whichis especially important in this case because thesludge contains so much fat and grease. There are nofilter belts that could become blocked by grease andfat. The operation costs of our screw presses are farlower than those of other sludge dewateringmachines.

The slaughterhouse and the wastewater treatmentplant were started up in 2005. The results have

remained excellent ever since. The required limits forchemical oxygen demand (COD), bio-chemicaloxygen demand (BOD), suspended solids (SS) and fat,oil and grease (FOG) were easily and instantly met.Our technical solution and project management wereso convincing that in January 2007 Danish Crownordered another HUBER HDF plant with chemical pre-treatment and a capacity of 120 m³/h for anotherslaughterhouse in Blans. This plant was started up infall 2007.

Alexander GhazinuriSectoral Sales ManagerBusiness Unit Industrial Solutionsgha@huber.de

Two screw presses ROTAMAT® RoS3 Size 3 withflocculation reactor for flotate sludge dewatering

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Complete Wastewater Treatment with a HUBER MembraneBio-Reactor Process at GZM Extraktionswerke AG, Lyss

GZM Extraktionswerk AG in Lyss is one of the largestprocessors of by-products from slaughterhouses inSwitzerland. Per year they process around 120,000metric tons of slaughterhouse waste and livestockcarcasses to produce meat-and-bone meal and fats.They generate 600 to 700 m³ highly pollutedwastewater. Until recently they pre-treated theirwastewater on-site and discharged it into themunicipal sewer system. As a result of the fact thattheir enormous freights of nitrogen and suspendedsolids caused serious operational problems andenormous costs at the municipal wastewatertreatment plant, the management decided toupgrade their industrial wastewater treatment plant.

After a fierce bidding contest with intensive scrutinyof the incoming bids in respect to cost-effectivenessand technical merits, Picatech HUBER AG, the SwissHUBER subsidiary in Kriens, received by the end of2005 the order for the supply of two turn-keymembrane filter units including their fullyautomated controls.

Half a year later construction of the concrete tankswas finished and the membrane filters and theirmechanical accessory could be installed. After theirinstallation, the tanks were filled with clean waterand the units tested for tightness and completeelectrical functionality.For start-up the tanks were filled with wasteactivated sludge from the local municipalwastewater treatment plant, intermittently aeratedand fed with the company’s wastewater. Only aweek later, the elimination performance of thesystem already far exceeded all expectations, andthe permeate effluent concentrations were far belowthe required limits. It is astonishing that the systemremoves over 99 % of the incoming nitrogen freight.The plant effluent meets the very stringentrequirements by the European Diretive for BathingWater Quality and is either reused as process waterin the factory or discharged into the Alte Aare river.Power consumption for the operation of our VRM®membrane filters is only a third of that required formixed liquor aeration. Our VRM® unit’s powerconsumption is considerably lower than that of ourcompetition.Johannes SchebestaProject ManagerPicatech HUBER AG, Kriens (CH)js@picatech.ch

Leak monitoring of the VRM’s bearing

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Filter chamber filled with clean water before start-up

Parameter Raw Wastewater Permeate Elimination

COD 5,000 mg/l 48 mg/l 99.0 %

BOD5 3,400 mg/l 4 mg/l 99.9 %

NH4-N 800 mg/l 0.2 mg/l 99.9 %

N tot 940 mg/l 8 mg/l 99.1 %

Suspended Solids 220 mg/l 0 mg/l 100 %

Sectional view through a membrane bio-reactor plant with VRM membrane filters

Operation Building

Membrane Filtration Post-Aeration Activated Sludge Tank

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Growing concern for our environment and risingpricing pressure are leading to projects for full orpartial treatment of industrial wastewater at factories.This is particularly the case in the meat industry. Withthis in mind, the HANS HUBER AG, a globally leadingsupplier of equipment and systems for wastewatertreatment, presented itself at the international meatindustry exhibition IFFA 2007.

At this exhibition we highlighted our technologies ofwastewater screening, dissolved air flotation andflotate sludge dewatering, but we also presented anddiscussed with interested visitors of our booth ourinnovative system of full-biological wastewatertreatment in membrane bio-reactors.

HUBER is especially focused on quality, tradition andinnovation. Our rotary fine screens ROTAMAT® Ro2 andour screw screens ROTAMAT® Ro 9, for example, areproducts that have been in use and proven for manyyears and all over the world, in many hundreds ofapplications. These robust screens, e.g. with 1 mmwedge wire spacing or 3 mm perforation, reliablyremove solids from wastewater and thus reduce theirfreight and protect downstream equipment, such aspumps, from wear, tear and clogging. After screeningfollows usually a dissolved air flotation (DAF) plant foreffective removal of fat, grease and suspended solids.If a DAF plant HUBER HDF is provided with chemicalpre-treatment, colloidally dissolved matter, such asblood, is additionally removed.

To permit savings of sludge hauling and disposal costs,we dewater and concentrate flotate sludges from DAFplants in our screw presses ROTAMAT® RoS 3 .

Combined screening and dissolved air flotation withchemical pre-treatment achieves enormous freightreductions and saves fees for the disposal ofwastewater into municipal sewers. Full-biologicalwastewater treatment in our membrane bio-reactor(MBR) system even permits directly discharge of theeffluent into surface waters or effluent reuse asprocess water in factories. Our MBR system is acombination of full-biological treatment and extremelyeffective filtration through our rotating VRM® ultra-filtration membrane units.Because of our extensive experience in the meatindustry, we received the order for the supply of acomplete wastewater treatment solution for DanishCrown in Hoersens, Denmark, Europe’s largestslaughterhouse (see separate report above).We learned from many visitors of our booth that ourtechnology is in great demand not only in WesternEurope, but also in Eastern Europe and Latin America.While in Western Europe there is need for upgradingand extension of existing treatment plants, newtreatment plants are required in other regions whereenvironmental concerns are now also taken seriously.Wherever and whatever it may be, HUBER is a verystrong partner of the meat industry.

Andreas BöhmSales EngineerBusiness Unit Industrial Solutionsboa@huber.de

HUBER booth at the international IFFA exhibition forthe meat industry in Frankfurt

HUBER - Competent Partner of the Meat Industry

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Washwater Recycling for Emirates Airlines in Dubai

The United Emirates’ economy is booming, itspopulation is growing rapidly and Dubai is theworld’s largest construction site. No wonderthat its infrastructure is under stress.Administration and private investors are doingtheir best to cope with this challenge and haveaccelerated their investment planning.EMIRATES, one of the world’s top-quality airlines, arereacting to increasing air traffic and have ordered 42planes of type A-380 from Airbus Industries. Thesegiants of the air require specially adapted passengerbridges and docking stations for baggage and freightloading. For this reason it was inevitable to enlargeand retrofit the Dubai airport (DBX) and to build athird and bigger hangar as well as new facilities forservice and maintenance, washing and evenrepainting of the giant airplanes.Water ReUse concepts are gaining ever moreinterest worldwide, but especially in the Middle East.Since freshwater is scarce and expensive in Dubai(almost all freshwater is desalinated seawater), theengineers of EMIRATES decided to recycle their washwater. In this way they want to save valuable waterresources and avoid use of expensively desalinatedfreshwater for their needs.When EMIRATES searched for a competent supplierof water recycling technology and consulted withtheir colleagues at other airports, the name HUBERwas mentioned several times, because we haveprovided successful wastewater and sludgetreatment solutions for a number of airportsworldwide. Because of our good references,EMIRATES entrusted us to develop and provide asolution for their specific needs.After several meetings with our client, we coulddefine and suggest a suitable solution. We couldmake use of our experience from a number ofprojects where we supplied wastewater systems forvehicle washing and for car paint lines of DaimlerChrysler, VW and Peugeot. We were thus able topredict the relevant wastewater characteristics andto propose a suitable solution for its treatment.The maximum wastewater flow from their washingand painting facilities was defined as 70 m³/h. Itcontains high concentrations of paint, varnish andparticles. This contamination must be reliablyremoved to permit water reuse.The first treatment step is fine-screening through arotary ultra-fine screen ROTAMAT® Ro2 with a wedge

Dissolved air flotation plant with tubular reactor forchemical pre-treatment, ready for shipment

wire spacing of 1 mm and a screen basket diameterof 1,000 mm. The solids are simultaneouslyremoved, dewatered and compacted in this unit.The screened wastewater is then collected in abalancing tank to equalize flow, freight and pH-value, which is neccessary for efficient and cost-effective chemo-physical treatment.A submersible pump forwards the mechanically pre-treated wastewater from the balancing tank to aHUBER HDF Size 7 dissolved air flotation (DAF) plantwith chemical pre-treatment. Coagulants andpolymers are dosed at various points into a tubularreactor where destabilization, coagulation andflocculation even of colloidal particles and emulsifiedgrease and oil is achieved. The generated stableflocs are efficiently removed in the DAF unit. Theclear effluent is collected in a storage tankwherefrom it is recycled and reused.Since safety and reliability are top priorities of theairline industry in general and of EMIRATES inparticular, all our equipment is redundant toguarantee reliable operation of the system at alltimes.We have already supplied our equipment, but start-up of the system was pushed back into 2008 due todelayed supply of the A-280 planes. We are veryconfident that our system will perform as efficientlyand reliably as anticipated.

Alexander GhazinuriSectoral Sales ManagerBusiness Unit Industrial Solutionsgha@huber.de

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The timber and paper industry is very importantworldwide. Their huge production and storagefacilities are some times responsible for severeenvironmental damage in their vicinity. Theirenormous water consumption causes problems,particularly in areas where water is scarce. Their aslarge wastewater disposal can lead to heavypollution of rivers and lakes. More stringentrequirements for environmental protection haveforced factories in many regions to build and operatewastewater treatment plants. This leads to thegeneration of rising quantities of wastewater sludge.Sludge dewatering is the first and very importantstep to reduce sludge volumes and to permit orderlydisposal of sludge cakes. Of course, it is not only veryimportant to remove as much sludge water aspossible, and minimize the amount of sludge, but it isalso absolutely neccessary to do this as cost-effectively as possible. Overall costs of sludgedewatering and disposal need do be compared.These costs include depraciation of the equipmentand the costs of its operation.The srew press HUBER ROTAMAT® RoS 3 is anespecially economical sludge dewatering machinefor the dewatering of both primary sludge (mainlyconsisting of fibers that have been screened fromwastewater) and secondary sludge (biomass that hasbeen generated during biological wastewatertreatment). With its great performance and cost-efficient operation our screw press has gained aleading edge in the industry. Operators all over theworld like their robust design, their reliability andease of operation and maintenance.Through our local partners in the Ukraine we supplied

six ROTAMAT® screw presses to one of the largestpaper mills in this country. As can be seen from thetable, the machines perform very well. Previously wehad performed pilot tests with a mobile container-mounted unit. In this way we could optimize thedesign of the supplied system. The management ofKIEVSKIY CARDBOARD AND PAPER MILL chose ourpresses for several reasons: Our press performedvery well and achieved excellent solidsconcentrations in the sludge cake; its operation andmaintenance is easy; its power consumption waslow; and, above all, our proposed system was veryeconomical. Our set-up of three twin pressesprovides for sufficient redundancy, i.e. operation isnot affected by service or maintenance of a unit. Byoperation of more or less presses, their overallcapacity is easily adapted to varying needs. Thissaves avoidable energy and other operating costs.For several years we have been a successful supplierof INTERNATIONAL PAPER, the largest papermanufacturer worldwide. End of 2007 INTER-NATIONAL PAPER sent us the so far biggest order weever received for sludge dewatering in the paper

3 x 2 ROTAMAT® screw presses RoS 3, side by side

ROTAMAT® Screw Press RoS 3 Prevails All Over the World in thepaper industry

Location: Ukraine (installed 2002)

Machines: 3 x 2 RoS 3screw presses

Application: Dewatering of primarysludge

Capacity: 50 - 60 m3/h overall

Feed concentration: 1.8 - 3.6 %DS

Cake concentration: 32.8 - 49.5 %DS

KCPM - KIEVSKIY CARDBOARD AND PAPER MILL

Location: Brazil (supplied)

Machines: 4 x 2 RoS 3 screw presses

Application: Dewatering of primarysludge

Capacity: 100 - 103 m3/h overall

Feed concentration: 2.5 - 2.7 %DSCake concentration: > 40 %DS (expected)

INTERNTAIONAL PAPER - VCP TRÊS LAGOAS

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4 x ROTAMAT® screw presses RoS 3, ready for shipment to Brazil

Dewatered primary sludge of a paper mill

industry. In 2005 we had already supplied fourROTAMAT® screw presses to one of their mills inBrazil. Obviously their performance and cost-efficiency was so convincing that they orderedanother eight ROTAMAT® screw presses for anothermill in this country. The eight presses will dewaterprimary sludge in their VCP TRÊS LAGOAS paper mill.Presently the presses are on their way to the site.Installation and start-up are planned for spring andsummer 2008. Because we have so much experienceof sludge dewatering in the paper industry, we do notexpect any problems from this application.

their existing belt filter press can not well cope withthe new conditions. This is why the factorymanagement was looking for a better sludgedewatering technology.We performed successful tests with our container-mounted pilot press for over a week. We could showthat our screw press can even dewater a blend of 90% secondary and 10 % primary sludge. Their existingbelt filter press was incapable to dewater such ablend. The average sudge ratio at this paper mill is55 % primary (14.3 %DS) and 45 % secondary (2.3%DS). Side by side operation with the same sludgedemonstrated the superiority of our ROTAMAT® screwpress. It achieved a cake solids with 45 %DS, which isalmost 10 %DS more than what the belt press couldreach.The staff of M-REAL was impressed and they selectedour ROTAMAT® screw press for their plant upgradingthat they have planned for 2008.

Andreas BöhmSales Team PaperBusiness Unit Industrial Solutionsboa@huber.de

Location: Switzerland(installed 2007)

Machines: 1 RoS 3 demonstrationunit

Application:Dewatering of blendedprimary and secondarysludge

Capacity: 7 - 10 m3/h

Feed concentration: 4.7 - 7.9 %DSCake concentration: 28.0 - 45.0 %DS

M-REAL PAPIER BIBERIST

The paper mill in Bibrist, Switzerland has been inoperation for over 140 years. Since 2001 it is ownedby the M-REAL concern. Presently they still use a beltfilter press for sludge dewatering in Bibrist. Due tomore stringent requirements on their effluent quality,they are upgrading their treatment system and theamount of their biological secondary sludge (wasteactivated sludge) will increase. Consequently theirratio of secondary to primary sludge will rise and

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Application of HUBER Equipment in Plants for Energy Recoveryfrom Biomass

Energy generation from biomass is gainingimportance, also for the HANS HUBER AG. OurBusiness Unit Industrial Solutions hasdetermined applications for various HUBERproducts and solutions for this emergingindustry.Whether it is our complete plant Ro 5-Bio, ourStrainpress, our dissolved air flotation plant HUBERHDF, our COANDA grit washer or grit classifier, ourwash-press WAP, even our sludge dryer KULT BT orBT+, or various kinds of HUBER sreens: ourequipment and its use are well known and highlyregarded by an increasing number of operators,consulting engineers and engineering companies.Our customers know the HUBER engineers ascompetent, experienced, innovative and dependablepartners. We do not only supply efficient and reliableequipment, but are also increasingly involved inprocess engineering; we provide “Industrial HUBERSolutions” for their needs. It is an importantadvantage that our industrial department can accessinformation and bundle expertise from other HUBERdepartments, e.g. for mechanical or sludgetreatment.Our mechanical pre-treatment unit Ro 5-Bio, forexample, has been used for many years in Germanyand other countries at plants for the biologicalfermentation of organic waste. This unit is especiallyadapted for the removal of coarse solids and gritfrom pulped waste. Pre-treatment with this unitprotects fermenter equipment from clogging andprevents formation of grit deposits on fermenterbottoms. Fifteen of our reliable low-maintenance Ro5-Bio units are in successful operation today.The same applies for the dewatering of thefermented product. Our ROTAMAT® RoS 3 screw pressis particularly efficient for the dewatering of suchfibrous material because of its robust design.Excellent dewatering efficiency and capture rate incombination with low operation and maintenancecosts make our entirely enclosed screw presses verycompetitive. We recently received the order for aturn-key project near Wiesbaden that includesdewatering of fermented bio-waste and treatment ofthe filtrate for reuse.While international projects are usually design andconstruction of new plants, German projects oftenrequire refurbishing and optimization of existingplants. We often have to adapt our solutions andequipment to given constraints. At a plant in

northern Germany, for example, we have replacedequipment of competitors with our superior wash-presses WAP 6 at three different locations. But sometimes we also provide HUBER solutions and supplyproducts for new systems in Germany.A British engineering company has selected ourStrainpress® as their standard screening machine forthe removal of plastics and other disturbing materialsfrom pulped bio-waste. All their current designsinclude this machine and during the last 15 monthswe have supplied seven units to this customer alone.Based on this experience, our Swedish subsidiaryHUBER Hydropress received an order for the supplyof two Strainpress® units and a grit classifier RoSF 3for a project in Scandinavia.Biogas generated from biomass or sewage sludge iscommonly used for co-generation of power and heat.Some of the heat is used for fermenter or digesterheating, but surplus heat can be used for thermaldrying of the dewatered product, e.g. in one of ourKULT-BT dryers (See our special report on page 18below).Currently there is a boom for fuel production frombiomass to reduce consumption of mineral oil. Ourproven process and product solutions are alsosuitable for such new processes. Coarse solids andgrit are also present in their raw materials, and theremaining biomass must be dewatered.The experience and expertise of our Business UnitIndustry will also be useful for innovative conceptsfor fuel generation from biomass.

HUBER PRODUCTSare more than machines -they are core components ofHUBER SOLUTIONS

Thomas NaglerSales EngineerBusiness Unit Industrial Solutionsnt@huber.de

Bernhard OrtweinSectoral Sales ManagerBusiness Unit Industrial Solutionsort@huber.de

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SP4 unit separating coarse material from the fermentation suspension

Iper – Belgium: Sludge dewatering with RoS3

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Coarse Solids and Grit Removal in Organic Waste FermentationPlants - The Beginning of a Success Story

Practiced environmental protection: about 400,000metric tons of organic solid waste have beenprocessed through the waste fermentation plant ofRECYBELL Umweltschutzanlagen GmbH, a wastemanagement company and subsidiary of theBELLERSHEIM Group, since the plant was built in 1999in Boden. Separately collected organic waste isfermented in a Bio-Stab process. The generatedbiogas and Bio-Stab soi are valuable products.The first treatment steps are sorting, including metalseparation, and milling. The milled waste is then fedinto a pulper where it is blended with over 70 °C hotwater and further comminuted. This water has beenremoved from the final product, is recycled through aHUBER HDF dissolved air flotation plant and thenheated. The solids concentration of the pulped wasteis about 12 %DS. The slurry is disinfected bypasteurization.Coarse solids and grit are removed from the hot slurryin our compact ROTAMAT® Ro 5-Bio unit. Wedeveloped the Bio version of our standard Ro 5 unitfor this specific application in Boden. The Bio versionis particularly sturdy and robust. 20 m³ batches of 70°C hot slurry are fed into the Ro 5-Bio unit and treatedfor 45 minutes. 16 batches are treated during 12hours of daily operation.Within the Ro 5-Bio unit, the coarse solids areremoved with a ROTAMAT® Ro 1-Bio screen that has ascreen basket diameter of 1,600 mm, a bar spacing of15 mm and a big auger pipe with a 711 mm (!!)diameter. The Bio version of our Ro 1 screen isprovided with two rakes and particularly reinforced.1.5 to 2 m³ debris, consisting of wood pieces, plasticfoil, bones and the like, are removed from everybatch. The removed and pre-dewatered solids aredischarged into our screenings compactor ROTAMAT®Ro 7, that is also provided with a 711 mm diameterauger pipe, and compacted to a solids concentrationof 30 - 35 %DS. The compacted solids are composted.

HUBER ROTAMAT® compact plant Ro 5-Bio andHUBER ROTAMAT® screenings compactor Ro 7 at theRECYBELL fermentation plant in Boden

The aerated grit chamber of the Ro 5-Bio was alsooptimized for this application where heavy solids,such as grit, stones, glass and bone fragments areremoved from a 8 %DS (!!) slurry of high viscosity.About 90 % of all particles with a size of 15 mm, orlarger, are removed in the grit chamber. Thedischarged grit solids are also composted.Mineral solids that have not been removed in our Ro5-Bio unit end up in the Bio-Stab soil. Most of theorganic solids are degraded in the thermophiliclyoperated fermentation reactor (about 55 °C) andtransformed into biogas, but some organic matter ispoorly biodegradable and also ends up in the finalproduct. This is no problem, just the opposite. Slowlydegradable organic carbon form humus and thusmake the Bio-Stab soil a valuable, nutrient-rich soilimprovement product that is applied on farmland inthe plant’s vicinity.

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HUBER ROTAMAT® screen Ro 1-Bio / 1600 / 15 mm with twin rakes and a 711 mm diameter auger pipe

We had to improve and optimize our ROTAMAT® Ro 5-Bio unit after start-up of the fermentation plant inBoden. Since the year 2000 it has been in virtuallytrouble-free operation.Our hard development and improvement work for thisfirst ROTAMAT® Ro 5-Bio application at a fermentationplant was worth the great effort. Thanks to theexcellent cooperation by our customer BELLERSHEIM,we could finally overcome all doubts concerning theunit’s applicability for the intended purpose. We havehad no prior knowledge of this units performance anddurability. We had to learn the hard way how we couldprotect the unit from the immense wear and tear thatis exerted by this type of material. We had to learn thehard way how to improve its design and operation.With our ROTAMAT® Ro 5-Bio we have developed aproduct of a special class. There is no comparableproduct for solids-liquid separation available in themarket.Our success story began in Boden, Switzerland. In themeantime there have been many sequels from otherparts of Europe. Ro 5-Bio units of three sizes are todayin successful operation in sixteen biogas plants andthirteen bio-waste fermentation plants . They allperform well, reliably and to our customers’satisfaction.

In addition, we have supplied four more ROTAMAT®Ro 1-Bio screens to three biogas plants. At two plantsthey replaced failing coarse solids removal equipmentof other manufacturers. Since then the mechanicalpre-treatment of both biogas plants has beenoperating well and without problems.

Bernhard OrtweinSectoral Sales ManagerBusiness Unit Industrial Solutionsort@huber.de

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Biogas is used to cogenerate power and heat. Thegenerated power is fed into the power grid. In somecountries there are regulations forcing power utilitiesto pay an exceptionally high price for power fromrenewable sources, such as biogas. Some of thecogenerated heat is needed for the operation ofbiogas plant, but there is often no local demand forthe surplus heat, at least not year round. Completeuse of the heat, however, is critical for theprofitability of biogas plants.An intersting option is year-round use of the surplusheat for sludge drying. Sludge is continuouslygenerated at wastewater treatment plants. Thesludge is usually dewatered, hauled over longdistances and then either applied on farmland orincinerated, e.g. in coal-fired power stations.Dewatered sludge still contains 70 - 85 % water.Transportation costs and fuel consumption can bereduced to one-fifth the sludge is dried sludgebefore transportation.The thermal value of driedsludge is comparable to that of brown coal, which isimportant for incineration.

Heat generation from biogas

The energy content of biogas is converted intopower with an efficiency of only 30 - 35 % while55-60 % is converted into usable heat. In Germanyand some other countries, power utilities must payan even higher price for power that is generated in abiogas cogeneration plant if the entire cogeneratedheat is also used, because cogeneration is the mostefficient use of fuel, whether fossil or renewable.

Exhaust Air

Condenser

H2O

Air Intake

Supply toDryer

Return from

Dryer

Dried Sludge> 90% TR

Sludge Silo

DewateredSludge

T = 90 °C

Heat Supply to BeltDryer KULT® BT+

Wide use of cogeneration is critical for our globalefforts to reduce energy consumption and green-house gas emission. It is critical to avoid or mitigateglobal warming and climate change.

Most biogas plants waste their surplus heat. Itshould be used for sludge drying instead. Operatorsof sludge dryers save fuel when they buy heat. Thisis good business for the operators of biogas plantsand sludge dryers - it is a win-win situation.

Sludge dryingMechanical sludge dewatering is an inexpensivemethod to remove water from sludge. For a longtime sludge dewatering has been the last step ofsludge treatment at wastewater teatment plants.Since landfilling of organic materials, such assewage sludge, is no longer permitted in Europe,and since its agricultural use has beenconteted - itwas even abandoned in some countries - ever moresludge is incinerated. This devolopment is furtheraccelerated by the new EU Wastewater SludgeDirective setting even more stringent requirementson the quality of sludges for agricultural use, e.g.further reduced limits for their copper and zinccontent.The consequence for the operators of wastewatertreatment plants is that sludge disposal becomesever more expensive. To minimize their sludgedisposal costs, they need to remove as much waterfrom their sludge as possible. Our belt dryers reducethe water content of sludge to around 10 %DS andthey operate continuously. While conventional drumor disc dryers need fossil fuel, our belt dryers canalso be operated with surplus heat from biogascogeneration, which is typically supplied at a

Supply of heat from biogas cogeneration to a beltdryer

Use of Heat from Biogas Cogeneration for Sludge Drying

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Biogas plant with power and heat cogeneration and use of surplus heat for sludge drying

temperature of 80 - 90 °C (175 - 195 °F). They need800 - 850 kWh of heat per metric ton of waterevaporation. As an example, a wastewatertreatment plant producing 5,000 m³ dewateredsludge per year requires approximately 3 millionkWh heat per year.Surplus heat from cogeneration is transferred viaheat exchangers from 80 °C (175 °F) hot water toheat air that is recirculated through the dryer beltsand sludge layers thereon. The hot air evaporatessludge water. It is then recirculated through acondenser, where water is removed from the air,and then heated up again. Air recirculationguarantees most efficient use of the supplied heat.The exhaust air is scrubbed and deodorized in abiofilter before it is releasen into the atmosphere.

Summary:KULT® BT+ sludge dryers are especially suitedfor heat supply of from biogas cogeneration.Operators of biogas plants can generate extrarevenues by selling their surplus heat. Our

sludge dryers operate continuously, so theycan be supplied with surplus heat at all times.Sludge drying reduces transportation anddisposal costs by around 80 %. Fuel savingsreduce carbon dioxide emissions and mitigateglobal warming.Generation of biogas from renewable sources,cogeneration of power and heat from thegenerated biogas, use of the cogeneratedheat for the production of a CO2-neutral fuel(i.e. dried sewage sludge), and finallyincineration of this fuel in power plants, is agreat system for the protection of ourenvironment.

Rudolf BognerDirectorBusiness Unit Sludgerbo@huber.de

Gas Storage

SubstrateFeeding

Main Fermenter SecondaryFermenter

Storage ofFermented

Product

Power/Heat-Cogeneration

Hot Water 2

Exhaust

Hot Air toBelt

Hot Air to BeltHot WaterSupply

Air Return from Condensor

Air Return from Condensor Cool WaterReturn

Haet Exchanger

Hot water 1

Cooling Water EmergencyCooling

Power to Grid

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Sucessful Solid/Liquid-Separation and Sludge Dewatering forLandfill Leachate Treatment

series of both proven and innovative technologies todetermine their performance and costs. Theymaintained and upgraded their existing biologicalpre-treatment and tested several processes forfurther COD elimination, including oxidation byhydrogen peroxide plus UV-radiation, activatedcarbon adsorption and coagulation / flocculation.They found out that the best COD reduction could beachieved with an innovative precipitation / coagu-lation / flocculation process. This process couldreduce the COD from about 3,500 mg/l to around200 mg/l. Their former process could only achievean effluent COD of 350 mg/l, and this withconsiderably higher energy consumption and noisegeneration.

In cooperation with the Osterode am Harz district,CUTEC-Institut GmbH (IFAT: Hall A3, Booth # 419)developed their DeSiFloc process for landfill

Landfill leachate treatment requires sophisticatedprocess technology and equipment. Undefined andfrequently changing composition of the leachatemake the design and operation of treatment plantsdifficult.

So far the leachate from the landfill of the Osterodeam Harz district has been biologally pre-treated andthen further treated in a chemo-phyical process withcoagulation and flocculation, sedimentation andactivated carbon adsorption. The resulting sludgewas dewatered with a centrifuge. Because theleachate includes not only bio-degradable, but alsorefractive substances, this treatment plant did notreliably produce an effluent in compiance with coplywith the consent standards. Treatment and disposalof the leachate were expensive.

For these reasons the landfill operators decided tolook for alternative treatment options. They tested a

Fig. 2: HUBER ROTAMAT® disc thickener RoS 2S (in front) and HUBER ROTAMAT® screw press RoS 3Q (behind)

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Fig. 3: Raw leachate; after coagulation; after “Floc-Former”; after RoS 2S (from left to right)

Fig. 1: The „Floc Former”

leachate treatment and built a demonstration plantat the site.

This innovative process features a special andpatent-protected technology for coagulation,flocculation and separation that can eliminate CODfurther than conventional processes. The newprocess can either be used for the treatment of rawleachate, or for the treatment of leachate that hasalready been pre-treated in an aerobic and/oranaerobic biological process.

Core of the DeSiFloc process is a so-called “Floc-Former”(See Figure 1). The very stable flocs that aregenerated in the Floc-Former are separated andthickened with our disc thickener ROTAMAT® RoS 2S(See Figure 2). Our thickener is fed with a suspendedsolids concentration of only 0.015 % and theseparated sludge has 3 %DS. The solids capture rateis around 99.9 %. The filtrate is clear (See Figure 3).The thickened sludge is then dewatered in our screwpress ROTAMAT® RoS 3Q (See also in Figure 2). Thesludge cake has a solids concentration between 16and 20 %DS. It is discharged via our screw conveyorROTAMAT® Ro 8T into a container for disposal.

The filtrate of our disc thickener RoS 2S has a qualitythat is almost sufficient to meet the consentstandard requirements. But for protection of thereceiving surface water, the filtrate is further treatedin a 150µm micro-filter and an activated carbonfilter.

The combination of the Floc-Former and ROTAMAT®equipment could reduce energy consumption forsludge treatment by 70 % in comparison with aconvenional decanter cenrifuge.

This combination could also increase the service lifeof the activated carbon filter by 30 %, even duringthe challenging start-up and optimization period.Optimization is not quite finished; further andsignificant improvement of our filtrate quality andfurther extension of the activated carbon filter’sservice life is to be expected.

This innovative process, including our very efficientand effective solid/liquid separation, thickening anddewatering equipment, opens new perspectives onlandfill leachate treatment.

Bernhard OrtweinSectoral Sales ManagerBusiness Unit Industrial Solutionsort@huber.de

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The nuclear power station Gösgen in Switzerland iscooled with water from the Aare river. After heavystorms or when snow is melting in the Alps, its flow ishigh and the water turbid. Process water is firstdecarbonated with lime and precipitated calciumcarbonate settled in a clarifier, but 10 - 20 mg/l ofcalcium carbonate remain in the effluent. Theremaining solids are presently removed in conventionalsand filters. Their effluent some times exceeds themaximum concentration of 1 m/g that the subsequention exchangers can tolerate.For this reason it is planned to retrofit or replace theexisting sand filters. We were invited to perform on-sitepilot testing with our HUBER CONTIFLOW® sand filter.During conventional sand filtration retained solidsaccumulate in a front sand layer. They reduce the poresize and increase the removal efficiency. On the otherhand, they increase the filter’s head loss. After back-washing, the removal effieciency is initially poor andonly gradually improves again.In our CONTIFLOW® sand filter we can always maintaina certain solids accumulation. When the head loss risesabove a certain limit, we only remove some sand fromthe lowest layer where the solids have accumulated(the CONTIFLOW® is an upflow filter), wash theremoved sand and return it to the top of the sand bed.During six weeks of testing, we were able to maintainthe effluent concentration consistently below 0.6 mg/land could reduce the washwater ratio from 6 to 2 %.

Wolfgang FischerProduct ManagerBusiness Unit Industrial Solutionsfiw@huber.de

Successful Pilot Testing at the Swiss Nuclear Power StationGösgen for Process Water Purification

Top view of our CONTIFLOW® pilot unit

Our CONTIFLOW® pilot unitAerial view of the Swiss nuclear power plant Gösgen

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The Chemtura Manufacturing Germany GmbHproduces at its factory in Waldkraiburg additives forthe plastic, rubber and adhesive industry. In the past,they precipitated and flocculated their wastewater,collected it in a great number of containers, let it restand settle, decanted the supernatant and dischargedit into the sewer system, dredged out the remainingsticky and highly viscous sludge and finally disposedit of as hazardous waste. The whole process waslaborious and led to severe pollution of their site.Their consulting engineers, Dr.-Ing. Steinle Ingenieur-gesellschaft für Abwassertechnik mbH, had becomeaware of our Ro S2S disc thickener during the last IFATexhibition (2005) and have it several timessuccessfully applied for process water treatment inthe food industry.The consulting engineer developed the concept touse our disc thickener as a filter for the rawwastewater. Precipitated sticky solids should bereliably separated and the filtered wastewater shouldthus be made suitable for further treatment.On-site testing with our mobile disc thickener quicklyproved the feasibility of their concept and theapplicability of our equipment. We received an orderfor the supply of a complete container-mounted unit,including pumps, flocculant station and controls.The stickiness of the solids even on polished stainlesssteel, however, forced us to find a new material,particularly for the filter screen that is normally madeof stainless steel fabric and cannot be coated.Heeding advice by Chemtura’s staff and theconsultant, and after we had performed tests withvarious materials, we determined that teflon would bethe best material because of its smooth surface and

View into our ROTAMAT® Ro S2S disc thickenerView of our container-mounted system

its excellent resistance against solvents. Wemanufactured a screen from a teflon plate andprovided it with a fine perforation. And we used apowder spraying and baking process to apply aresistant coat of teflon on all interior surfaces of ourequipment that are in contact with the stickywastewater.Thanks to the compactness of our disc thickener, wecould fit the entire equipment into a 20’ container. Ona footprint of only 14 m², up to 20 m³/h of wastewaterare full-automatically conditioned, separated withinan entirely enclosed system into a liquid and solidstream, and both streams are properly forwarded tofurther treatment and disposal.

Harald NeumannProduct ManagerBusiness Unit Sludgenh@huber.de

A New Application of our ROTAMAT RoS 2S Disc Thickener inthe Chemical Industry

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Through pilot testing we could prove that themembrane bio-reactor process with our rotating VRMmembrane filters is suitable for the treatment ofwastewater from the textile industry. The permeatequality is so good, that the permeate effluent can bereused as process water.Bamberger Kaliko GmbH has been a successful textilefinisher for over 135 years. Their products includefabrics for book binding, blinds and various othertechnical textiles. Bamberger Kaliko is a worldwideleading manufacturer of roller blinds. It should beemphasized that the company uses onlyenvironmentally sound finishing processes that do notrequire use of solvent based materials, chlorine,chlorofluorocarbons (CFC) or polyvinylchloride (PVC).Textile finishing processes consume much water. This isthe reason why Bamberger Kaliko is very interested ininternal wastewater recycling. Precondition is that thequality of the recycled process water is so good thatsubsequent dying processes are not affected. Criticalin this respect are iron and salt concentrations andwater hardness.Presently Bamberg Kaliko draws process water fromtwo wells, removes iron and reduces hardness beforeits use. Table 1 shows iron concentrations of the wellwaters. Values with the prefix “u” are below thedetermination limit of the used cuvette tests and areinaccurate, but still useful for orientation. Also shown inTable 1 are iron concentrations of the permeate of theHUBER VRM pilot plant.Wastewater from the factory is presently partiallytreated on-site in a biological treatment plant and thendischarged into the municipal sewer. Removed solidsand sludge are thickened, dewatered and thencomposted. The biosolids product can be used for landreclamation.

Because of increasing manufacturing capacity andgradually declining water supply of their shallow well,Bamberger Kaliko has been considering feasibility ofinternal water recycling for some time. Since this wasnot possible with conventional technology, theresponsible manager of Bamberg Kaliko approachedHUBER and asked us to develop a suitable concept.We performed pilot tests over a period of four monthsto find out whether our membrane bio-reactor (MBR)process is suitable for this application. We also wantedto determine the required design parameters for thebiological process, membrane filtration and pre-treatment.We took wastewater from the outflow of the existinglamella separator. We quickly found out that the solidsconcentration was too high, because too many solidsaccumulated in the membrane bio-reactor. This wouldlead to a too low sludge age in the reactor and poorbiological treatment efficiency. For better solidsremoval we provided several clarifiers. Due to the factthat there is not enough space for sufficiently largeclarifiers available on-site, we decided to performadditional tests with our dissolved air flotation pilotplant HUBER HDF .

Features and technical data of our VRM pilotplantOur VRM pilot plant comprises two chambers. Theactivated sludge chamber has a volume of 12 m³.Biological treatment and degradation of the generatedbiomass under aerobic conditions takes place in thischember. The second and far smaller chamberincludes a VRM membrane filter (See Figure 2) and isconnected with the first chamber via a recirculationpump and an overflow.A permeate pump generates underpressure in themembrane mudules, drawing the permeate from thefiltration chamber through the membranes. By rotationof the membrane filter and rising air bubbles, ascouring cross-flow is generated on the membranesurface. The pilot plant VRM 20/36 has a membranesurface of 108 m². It is designed for an average 2 m³/hpermeate flow.

Features and technical data of our HDF pilotplantBy coagulation, flocculation and neutralizationcolloidally dissolved particles are transformed intostable macro-flocs that can be removed by dissolvedair flotation. Coagulant, flocculant and acid or base are

Bamberger Kaliko –A Model for Wastewater Recycling in the Textile Industry

Unit Fe II Fetot Fe III

ShallowWell [mg/l] 0.258 0.608 0.351

DeepWell [mg/l] 0.034 u 0.094 0.060

Per-meate [mg/l] u 0.048 u 0.103 0.056

Table 1: Iron concentrations of well waters andpermeate effluent from the HUBER VRM pilot plant

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Pilot testing procedure and important results

Both pilot tests were very successful. The dissolved airflotation plant not only effectively removed almost allsolids, but also neutralized the widely varying pH-valueof the raw wastewater. The effluent from the flotationplant had a quality that was more than sufficient for itsfurther treatment in the membrane bio-reactor.

We could terminate the flotation tests after only twoweeks and extend the MBR testing duration to threeand a half months. This allowed us to determinereliable data concerning biological degradability of thewastewater, membrane performance and resistance,and other fundamental process design informationthat we need for upscaling to a full-sized plant.

The VRM pilot plant was operated by HUBER employeduniversity graduands in cooperation with theoperators of Kaliko’s existing wastewater treatmentplant. Samples of the inflow, permeate effluent andbio-reactor content were taken and analyzed threetimes per week. Biological parameters are shown inTable 2. Concentrations of iron, calcium andmagnesium and the hardness of the effluent were alsoanalyzed occasionally (See iron concentration inTable 1) to find out whether the effluent can be reusedas process water. Since our pilot plant did not include adenitrification reactor, great nitrogen removal couldnot be expected.The results from our pilot testing proved that pre-treated wastewater can well be treated with an MBRsystem, if most of the solids are removed during pre-

VRM pilot plant operated at the Kaliko factory

View into the membrane filter chamber (filled halfwith clean water)

subsequently dosed into a tubular reactor withturbulent flow. Destabilization, coagulation,neutralization and flocculation take place in thisreactor.After chemical pre-treatment, the wastewater is fedinto the dissolved air flotation plant. Within the feedpipe, the wastewater is intensively blended with micro-bubbles that are generated by sudden pressure drop ofpressurized, air-saturated recycle water when itstreams through a valve. The pressurized water isintensively mixed with air in a special pump andsaturated with air in a subsequent saturation pipe.The optimal bubble diameter is about 50 micron. Themicro-bubbles attach to the flocculated solids andmake them lighter than the surrounding water. Thesolids float up to the water surface in the flotation tank.The solids are thickened and skimmed off as flotatesludge. The effluent from the flotation tank is virtuallysolids-free. A portion of it is recycled to generate thepressurized and air-saturated water.

Container-mounted HDF pilot plant

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treatment. It is also important that the feed flow intothe MBR system has a consistent quality. Chemicaltreatment with subsequent dissolved air flotationshowed excellent pre-treatment results. Thecombination of equalization in the existing buffer tanksand neutralization as part of the DAF teatmentguarantees sufficient consistancy. The effluent of theDAF unit contained few solids and had a sufficientlyconsistent quality. It can be treated in an MBR system.It is not the objective of the upgrading of Kaliko’sexisting wastewater treatment plant to increase itscapacity, but to improve its effluent quality. Somecomponents of the existing plant, such as buffer tanksand sludge treatment equipment, can be maintainedand used, but the existing biological treatment stageneeds to be replaced with a membrane bio-reactor.Upscaling from the pilot plants to a full-size plant with a500 m³/d capacity is well possible based on data fromour extensive pilot testing.As mentioned before, it is neccessary to remove ironand water hardness, if the effluent is reused as processwater, in order to protect sensitive dying processes inthe factory. This is nothing new, the well water also hadto be treated (See Table 1). Capacity and performanceof the existing ion exchangers and filters are sufficientto treat the effluent from the MBR system.

Upgrading concept for the full-size plant

Ongoing use of as many components of the existingplant as possible is another objective. The existingbuffer tank will be enlarged and divided into two tanks.One tank will still be used as buffer tank for the rawwastewater in order to feed equalized flow to the DAF

Unit COD NH4-N NO2-N NO3-N Ntot PO4-P

AverageInflow [mg/l] 2810 10,18 1,03 4,36 45,00 19,08

AveragePermeate [mg/l] 154 0,73 0,28 7,28 20,1 8,01

Reduction [%] 95,2 92,9 72,9 n. a. 55,4 58,1

Unit Fe II Fetot Fe III Ca Mg °dH

AveragePermeate [mg/l]* 0,30 0,45 0,16 200 16,4 32,3

*with the exemption ofhardness

and its chemical pretreatment reactor . The other tankwill be transformed into the bio-reactor of the MBRsystem. The existing screens and the sludgedewatering equipment can be maintained andintegrated into the new plant.The upgrading will be done in two stages. During thefirst stage the dissolved air flotation plant will beinstalled. The effluent of the DAF has such a goodquality that it can be disposed into the muncipal sewersystem until the MBR will be started up. In this waythere is sufficient time for the second stage. Thisincludes retrofitting a portion of the existing buffer tankinto a bio-reactor and installation of the membranefilters.

Two membrane filters will be installed to provide forsuffiecient redundancy. The same applies for otherimportant components, such as pumps and blowers.This redundancy guarantees high reliability ofoperation.

Bernhard OrtweinSectoral Sales ManagerBusiness Unit Industrial Solutionsort@huber.de

Table 2: Inflow and permeate effluent characteristics of the VRM 10/36 pilot plant

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Hans Huber AGMaschinen- und AnlagenbauPostfach 63 · D-92332 BerchingTel. + 49 - 84 62 - 201- 0Fax + 49 - 84 62 - 201- 810info@huber.deInternet: www.huber.de

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