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IV. Wastewater Treatment Technologies

Topic IV. 10. Wastewater Treatment Facilities with Attached Biomass - Trickling Filters: Kinds,

Structures, Basic Technological Parameters

Kinds of Trickling Filters

I. According to the technological parameters Low rate trickling filters High rate trickling filters Rotating disks

II. According to the carrying material Natural (gravel) Plastics

Grains Sheets

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Wastewater Treatment Facilities with Attached Biomass

Kinds of Trickling Filters

III. According to the necessity of wastewater recirculation With purified wastewater recirculation Without purified wastewater recirculation

IV. According to the the kind of biological processes Aerobic

With natural circulation of air With ventilators or blowers

Anaerobic

V. According to the technological stages One stage (single) Two stages

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Kinds of Trickling Filters

Technological Schemes with Recirculation

a - with purified wastewater recirculation

б - with purified wastewater and

secondary sludge recirculation

b - with interim settling

1 - primary settling tank

2 - trickling filter

3 - secondary clarifier

4 - secondary sludge

5 - recirculating wastewater

6 - primary and secondary sludge

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Kinds of Trickling Filters

Scheme of Two Stage Trickling Filters1 - primary sludge; 2 - first stage trickling filter; 3 - first stage secondary clarifier; 4 - second

stage trickling filter; 5 - second stage secondary clarifier; 7 - recirculating purified wastewater; 8 - primary and secondary sludge

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Trickling Filters

Structures

General Scheme of Trickling Filter (Round in Plane)1 - biomass carrier; 2 - wall; 3 - drainage bottom; 4 - drainage collecting channel;

5 - jet wastewater distributing device; 6 - ventilation orifices

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Trickling Filters

Structures

Jet Wastewater Distribution Device

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Trickling Filters

Structures

Drainage Bottom of Trickling Filtera - bricks; б - arch drainage elements; b - concrete bar racks; г - drainage bottom supporting elements

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Trickling Filters

Structures

Rotating Disks (Biodisks)

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Trickling Filters

Basic Technological Parameters

qf - surface hydraulic load, m3/m2.d

qw - volume hydraulic load, m3/m3.d

OC - oxidizing capacity, gBOD5/m3.d

OL - organic load, gBOD5/m3.d

Q - wastewater design flowrate, m3/d

W - trickling filter working volume, m3

Qr - recirculating wastewater flowrate, m3/d

n - recirculation ratio

L0 - influent BOD5 concentration, g/m3

L - effluent BOD5 concentration, g/m3

Lmix - mixed wastewater BOD5 concentration, g/m3

F - trickling filter horizontal area, m2

WQLLOC /)( 0

WQLOL /.0

LL

LL

Q

Qn

mix

mixr

0

fqnQF /)1(