Activated Sludge Troubleshooting Chart - Analysis · Activated Sludge Troubleshooting Chart The...
1
Activated Sludge Troubleshooting Chart The Traffic Light System RED - your plant is at risk of failing consent – get in touch! [email protected] +44 (0)1924 242255 AMBER - something in the plant has changed and needs further investigation and a course of action. GREEN - the plant is stable and healthy. EXAMINING ACTIVATED SLUDGE PROTOZOA FOAMING & BULKING FILAMENTS METAZOA AND HIGHER LIFE FORMS FLOCS The number and type of micro-organisms provide an indication of the sludge age and final effluent quality. The disappearance of higher life forms and appearance of flagellates can indicate the site has been upset. Protozoa and metazoan help to maintain quality of the flocs, like filaments they are indicator organisms. Filaments thrive in a range of conditions including low dissolved oxygen, septic wastewaters, presence of FOG and nutrient deficiency. They are indicator organisms. Microthrix & Nocardia are known to foam,Type 021N and Thiothrix can produce SSVI values in excess of 200 ml/g, high final effluent solids risk! We have experience of looking at over 2000 samples over 20 years; in all likelihood if you’ve got it, we’ve seen it before and resolved the issue. We offer training on microscopy and WE FIX activated sludge plants! 1. Make the slide – a small drop placed on the slide with a cover slip. 2. Observe at x100 magnification. - Classify flocs - Clarity of bulk liquid - Filament abundance and influence upon flocs - Protozoa and metazoan identification and count - Other observations – tetrads, monocolonies, zoogloea 3. Compress the slide, stain if needed, observe under oil immersion. - Identify the filaments at x1000 magnification 4. Compile into an interpretational report. 5. Combine this data with site observations and data to develop a SMART action plan. THE IMPORTANCE OF A WELL SETTLING ACTIVATED SLUDGE The SSVI (Stirred Sludge Volume Index) test is universally applied to activated sludge plants to quantify the rate of settlement. A bulking sludge is where the SSVI3.5 (carried out at a concentration of 3.5 g/l) reaches 120 ml/g, although many sites will set an amber trigger point at 100 ml/g. The filamentous micro-organisms present and nature of flocs largely control the settlement rate of the sludge, which may not settle at all at times! This guide aims to help you identify specific filaments, flocs and micro-organisms. WHAT YOU SEE UNDER THE MICROSCOPE CHANGES BEFORE PERFORMANCE WORSENS! ROUTINE MICROSCOPY IS ESSENTIAL. SSV1<90 SSV1<120 No SSV1 Weak, diffuse flocs are more prone to poor settlement, especially when combined with high filament numbers. Kinetic selectors can be retrofitted to activated sludge plants to improve floc structure and reduce filament levels. GET IN TOUCH! [email protected] BULK LIQUID A turbid bulk liquid can indicate that the site is struggling to achieve consent. If turbidity is a recent change it may indicate the plant has been subjected to a toxic/ shock load. This observation may be accompanied by the presence of immature species of protozoa, including flagellates. Clear Turbid Firm compact floc Round shaped floc Weak diffuse flocs Compact flocs, but filaments bridging TRAINING Our experienced team can train your staff on microscopic analysis of activated sludge and optimising activated sludge plants FILAMENT NUMBERS 0 None 1 Few (occasional) 2 Some (not in all flocs) 3 Common (1-5 per floc) 4 Very Common (5-20 per floc) 5 Abundant (>20 per floc) 6 Excessiv e (filaments excessive) Flagellate Crawling Ciliate Free swimming Ciliate Stalked Ciliates Type O21N – characteristic oval shaped cells (x1000) Thiothrix (x1000) Straight edged & broken filament following chemical dosing Beggiatoa (x1000) – straight edged with shiny sulphur inclusions Zoogloea (low nutrients) Tetrads (nutrient deficient) Fungus (low pH and nutrients, phenols) M. Parvicella – spaghetti like bundles (x100) Nocardia – true branching (x1000) Rotifers Nematodes Aeleosoma worm Foam on aeration basin surface.What is it, the cause and solution? Foam overtops aeration tank.Why? Understand Microbial or detergent foam? High solids in the final effluent and bulking sludge.Why? Severe foaming.Why? Tardigrade (water bear) Avoid the RED , act on AMBER and stay in the GREEN To discuss how we can help please get in touch - [email protected] +44 (0)1924 242255 Aqua Enviro, 8 Appleton Court, Calder Park,Wakefield,WF2 7AR, UK www.aquaenviro.co.uk
Transcript of Activated Sludge Troubleshooting Chart - Analysis · Activated Sludge Troubleshooting Chart The...
-
Activated Sludge Troubleshooting Chart
The Traffic Light SystemRED - your plant is at risk of failing consent – get in touch! [email protected] +44 (0)1924 242255
AMBER - something in the plant has changed and needs further investigation and a course of action.
GREEN - the plant is stable and healthy.
EXAMINING ACTIVATED SLUDGE
PROTOZOA
FOAMING & BULKING
FILAMENTS
METAZOA AND HIGHER LIFE FORMS
FLOCS
The number and type of micro-organisms provide an indication of the sludge age and final effluent quality. The disappearance of higher life forms and appearance of flagellates can indicate the site has been upset.
Protozoa and metazoan help to maintain quality of the flocs, like filaments they are indicator organisms.
Filaments thrive in a range of conditions including low dissolved oxygen, septic wastewaters, presence of FOG and nutrient deficiency. They are indicator organisms. Microthrix & Nocardia are known to foam, Type 021N and Thiothrix can produce SSVI values in excess of 200 ml/g, high final effluent solids risk!
We have experience of looking at over 2000 samples over 20 years; in all likelihood if you’ve got it, we’ve seen it before and resolved the issue.
We offer training on microscopy and WE FIX activated sludge plants!
1. Make the slide – a small drop placed on the slide with a cover slip.
2. Observe at x100 magnification. - Classify flocs - Clarity of bulk liquid - Filament abundance and influence upon flocs - Protozoa and metazoan identification and count - Other observations – tetrads, monocolonies, zoogloea
3. Compress the slide, stain if needed, observe under oil immersion. - Identify the filaments at x1000 magnification
4. Compile into an interpretational report.
5. Combine this data with site observations and data to develop a SMART action plan.
THE IMPORTANCE OF A WELL SETTLING ACTIVATED SLUDGE
The SSVI (Stirred Sludge Volume Index) test is universally applied to activated sludge plants to quantify the rate of settlement.
A bulking sludge is where the SSVI3.5 (carried out at a concentration of 3.5 g/l) reaches 120 ml/g, although many sites will set an amber trigger point at 100 ml/g.
The filamentous micro-organisms present and nature of flocs largely control the settlement rate of the sludge, which may not settle at all at times!
This guide aims to help you identify specific filaments, flocs and micro-organisms.
WHAT YOU SEE UNDER THE MICROSCOPE CHANGES BEFORE PERFORMANCE WORSENS! ROUTINE MICROSCOPY IS ESSENTIAL. SSV1
