We think you have liked this presentation. If you wish to download it, please recommend it to your friends in any social system. Share buttons are a little bit lower. Thank you!
Presentation is loading. Please wait.
Published byAustin Regan
Modified over 2 years ago
Urban Water Systems12 Sludge treatment© PK, 2006 - page 1 12Sludge Treatment 12.1 Overview 12.2 Thickening 12.3 Biological sludge stabilisation 12.4 Volume reduction 12.5 Sludge disposal Technische Universität Dresden Department of Hydro Science, Institute for Urban Water Management Peter Krebs Urban Water Systems
12 Sludge treatment© PK, 2006 - page 2 12.1 Overview 12 Sludge treatment
Urban Water Systems12 Sludge treatment© PK, 2006 - page 3 Composition of sludge All non-degraded compounds extracted from wastewater are found in the sludge Micro-organisms Viruses, pathogens, germs in general Organic particles, heavily bio-degradable Organic compounds, inert, adsorpted to sludge flocs Heavy metals Micro-pollutants, pharmaceuticals, endocrine disrupters Predominantly water
Urban Water Systems12 Sludge treatment© PK, 2006 - page 4 Goals of sludge treatment Volume reduction Elimination of pathogenic germs Stabilisation of organic substances Recycling of substances Thickening Dewatering If used in agriculture as fertiliser or compost Gas production Reduction of dry content Improvement of dewatering Reduction of odour Nutrients, fertiliser Humus Biogas
Urban Water Systems12 Sludge treatment© PK, 2006 - page 5 Overview Thickening Hygienisation Stabilisation Dewatering Drying Incineration Process water Biogas Energy Agriculture Disposal site Atmosphere Wastewater treatment Primary, secondary, tertiary sludge Construction industry Gujer (1999)
Urban Water Systems12 Sludge treatment© PK, 2006 - page 6 Sludge Treatment Alternatives Eckenfelder & Santhanam (1981)
Urban Water Systems12 Sludge treatment© PK, 2006 - page 7 12.2 Thickening 12 Sludge treatment
Urban Water Systems12 Sludge treatment© PK, 2006 - page 8 Thickening by Gravity Gravitative separation, similar to settling tank Supernatant is introduced to primary clarifier or – if floatables and grease contents are high – to grid chamber Additional mechanic stirring to enhance flocculation and extraction of water and gas Thickened sludge is withdrawn from hopper and introduced to sludge treatment For an efficient thickening process the development of gas bubbles must be prevented
Urban Water Systems12 Sludge treatment© PK, 2006 - page 9 Gravity Thickener Thickened sludge Picket fence Scum scimmer Inflow Sludge liquor
Urban Water Systems12 Sludge treatment© PK, 2006 - page 10 Dimensioning of gravity thickeners surface Solids overflow rate Typical values for solids overflow rate q TSS,Th and concentration of thickened sludge X Th q TSS,Th X Th Primary sludge Primary and secondary sludge 80 – 120 50 - 7050 - 100 80 - 150 q TSS,Th Specific solids overflow rate (kg TSS / (m 2 d)) Q WAS Inflow to thickener (m 3 /d) X Th,in Solids concentration in thickeners inlet (kg TSS / m 3 ) A Th Surface of thickener (m 3 ) Secondary sludge25 - 3020 - 35
Urban Water Systems12 Sludge treatment© PK, 2006 - page 11 Thickening by Flotation Pre treatment: mostly chemical flocculation Air bubbles attach to solid particles lower specific gravity than water Slude is placed in contact with air-saturated water (full flow or recycle pressurization) Floating Sludge bubble composite is collected at the surface Water is recovered under a scum baffle and removed
Urban Water Systems12 Sludge treatment© PK, 2006 - page 12 Thickening by Flotation
Urban Water Systems12 Sludge treatment© PK, 2006 - page 13 Flotation unit
Urban Water Systems12 Sludge treatment© PK, 2006 - page 14 12.3 Biological sludge stabilisation 12 Sludge treatment
Urban Water Systems12 Sludge treatment© PK, 2006 - page 15 Anaerobic mesophilic sludge stabilisation Content of digester is mixed Sludge and water obtain a similar residence time Storage unit Not heated little biological activity Heated to 33 – 37°C process rates are higher Digester Not mixed separation of sludge and process water, which is directed to WWTP Further thickening Control of loading to WWTP, app. 10% of N-loading
Urban Water Systems12 Sludge treatment© PK, 2006 - page 16 Processes in digester Biogas production: 63% CH 4 (Methane) 35% CO 2 2% other gases (N 2, H 2, H 2 S) electricity and heating Anaerobic degradation Organic nitrogen is converged to NH 4 + N-loading of WWTP Degradation of organic substances of app. 50%
Urban Water Systems12 Sludge treatment© PK, 2006 - page 17 Characteristic values of digester Mean residence time of sludge Small units, badly mixed Medium size units with mixing Large plants with mixing < 30 d 20 d 12 – 16 d Biogas production related to degradation of organic substances 0.9 m 3 / kg VSS degr. Degradation of organic substances40 – 55%
Urban Water Systems12 Sludge treatment© PK, 2006 - page 18 Activated sludge tank is larger than that combined with an anaerobic sludge stabilisation No biogas production High sludge age SRT, app. 25 d Simultaneous aerobic sludge stabilisation No primary clarifier no primary sludge Possibly combined with storage or thickener unit Stable and simple operation
Urban Water Systems12 Sludge treatment© PK, 2006 - page 19 12.4 Volume reduction 12 Sludge treatment
Urban Water Systems12 Sludge treatment© PK, 2006 - page 20 Volume reduction Water content in stabilised sludge > 95% ! Reduction of water content and volume Sludge volume With water content non-linear relation!
Urban Water Systems12 Sludge treatment© PK, 2006 - page 21 Volume reduction
Urban Water Systems12 Sludge treatment© PK, 2006 - page 22 Dewatering Conditioning with flocculation agents (poly-electrolytes) for efficient dewatering DecanterContinuous Chamber filter press (large plants) Batch-wise Belt filter press (small plants) continuous Centrifuge Hydraulic pressure through plates in water-tight chambers UnitOperationMethod Pressed between two filter belts around staggered rollers W DS > 0.7< 0.3 > 0.6 0.4 > 0.7 0.3
Urban Water Systems12 Sludge treatment© PK, 2006 - page 23 Drying bed Thin sludge layer (< 20 cm) Sand layer as drainage and filter layer Sludge isfirst dewatered by drainage then air-dried through evaporation Applicable for small plants Plant typeSpecific surface Only mechanical treatment13 PE/m 2 Trickling filter6 PE/m 2 Activated sludge plant4 PE/m 2 Dimensioning W 0.55 (Imhoff, 1990)
Urban Water Systems12 Sludge treatment© PK, 2006 - page 24 Drying Vaporisation of water content Partial drying W 0.3 – 0.4 Full drying W down to < 0.1 Contact drying over heated areas Drying by convection through hot air counter-current inlet app. 600°C, outlet app. 300°C (Imhoff, 1999) For large plants Disposal is critical: fire, dust explosion In granulate form as fertiliser
Urban Water Systems12 Sludge treatment© PK, 2006 - page 25 12.5 Sludge disposal 12 Sludge treatment
Urban Water Systems12 Sludge treatment© PK, 2006 - page 26 Use in agriculture Recycling of nutrients, from stabilised sludge Problems Acceptance Heavy metals Micro-pollutants, pharmaceuticals, endocrine disruptors Liquid sludge Dewatered sludge Dried sludge P- and N-fertiliser P-fertiliser, N as storage product P-fertiliser Sludge treatmentFertiliser * * Limit re. over-fertilisation
Urban Water Systems12 Sludge treatment© PK, 2006 - page 27 Composting Aerobic biological degradation of organic substances PrerequisitesStabilisation Dewatering Hygienisation Approach Structure means: straw, wood, saw dust, wood chips Mixture app. 1:1 Water content app. 0,65 Requirements are more demanding than for sludge use as fertiliser!
Urban Water Systems12 Sludge treatment© PK, 2006 - page 28 Incineration Use of energy content, but not of nutrients Mono incineration (sludge exclusively) Co- incineration In solid waste incinerators In cement production, ash is bounded to cement Calorific value of sludge high enough no biogas use before, no stabilisation Water content not minimised (no full drying) Fluidised bed incinerator, incineration at 800 – 950°C in fluidised sand bed Expensive! In coal power station
SOLID/ SLUDGE MANAGEMENT. S OLID AND B IOSOLIDS SOLIDS AND BIOSOLIDS The largest waste (in volume) Form:liquid or semisolid liquid ( % solid) Term.
Pollutants in wastewater -- Revisited Ammonia Organic matter Nutrients Pathogens Color Metals and SUSPENDED SOLIDS.
Virtual Tour of Municipal Wastewater Treatment Plant (WWTP) Prepared by Dr. Richard O. Mines, Jr., P.E. Mercer University Environmental Engineering Department.
ERT 417/4 WASTE TREATMENT IN BIOPROCESS INDUSTRY CH 14 – Thickening, Aerobic & Anaerobic Digestion Prepared by: Pn. Hairul Nazirah Abdul Halim.
Wastewater Treatment. Municipal WW Management Systems Sources of Wastewater Processing at the Source Wastewater Collection Transmission and Pumping.
Module 91 Sludge Treatment and Disposal Discuss the various methods of sludge treatment Describe the processes involved in their treatment Have an.
Sewage Treatment. Urban Waste Water Sewage: Wastewater produced by residential and commercial establishments and discharged into sewers What is in it?
Wastewater Treatment. Municipal WW Management Systems Sources of Wastewater Processing at the Source Wastewater Collection Transmission and Pumping Treatment.
Waste Water Treatment (Sewage Treatment) Outline Objectives Outline of treatment process (flow diagram) Preliminary treatment Primary treatment (sedimentation)
ANAEROBIC DIGESTION OF MUNICIPAL WASTE PRESENTED BY: Mr. Thomas McAndrew Ms. Ciara Coughlan Ms. Ann Phair.
1 CTC 450 Review Secondary Treatment Secondary Treatment –Trickling Filters –Biological Towers –Activated Sludge –RBC –Lagoons –Septic Tanks.
Dr. Mohab Kamal. Sludge is produced from the treatment of wastewater in on-site (e.g. septic tank) and off-site (e.g. activated sludge) systems. This.
Urban Water Systems11 Wastewater treatment© PK, 2005 – page 1 11Wastewater Treatment 11.1 Boundary conditions 11.2 Layout of a wastewater treatment plant.
Thermo-Chemical Processes for Biomass Conversion (TCP) Marten Grau University of Halle (Germany)
Wastewater Treatment. Wastewater Treatment Methods Wastewater treatment system consists of a combination of different treatment units, which either reduce.
SLUDGE u Screenings u Grit u Scum u Solids u Biosolids Substances responsible for offensive character of wastewater Highly organic in nature Pathogenic.
PSSA Preparation. Question 1(no calculator) D Question 2 (no calculator)
Wastewater Treatment Processes. To prevent groundwater pollution To prevent sea shore pollution To prevent soil pollution To prevent marine life pollution.
Logo Module 5: Animal Manure and Process-Generated Wastewater Treatment By Saqib Mukhtar.
Conventional Wastewater Treatment Plant 2. Future Development in Wastewater Treatment Plant 3. What are the problems created by wastewater ? 4.
Water Waste Treatment. Outline 1. What is Sewage? 2. Sewage treatment a) Primary stage of Sewage treatment b) Secondary stage of Sewage treatment c) Tertiary.
1 IV. Wastewater Treatment Technologies Topic IV. 11. Sludge Treatment: Processes, Facilities, Basic Technological Parameters Processes of Sludge Treatment.
TRP Chapter Chapter 6.3 Biological treatment.
Weathering and Soil Test Review.
INTRODUCTION TO THE TREATMENT OF TANNERY EFFLUENTS every tanner What every tanner should know about effluent treatment U nited N ations I ndustrial D evelopment.
1 Waste Treatment, Physical ENVE Physical Separation n To remove particles –Particles of contaminant –Particles generated by chemical or biological.
Biological Treatment Processes. Outline Overview 3.1 Criteria for Successful Biological Treatment 3.2 Principles of Biological Reactions 3.3Wastewater.
Course TEN-702 Industrial waste management unit-2 Lecture -13.
25 seconds left….. 24 seconds left….. 23 seconds left…..
Wastewater Treatment. Purpose: To manage water discharged from homes, businesses, and industries to reduce the threat of water pollution.
14 th September Life Cycle Assessment of biomethane public transport Jan Paul Lindner Dept. Life Cycle Engineering (GaBi) Chair of Building.
CE 370 Sedimentation. Sedimentation Objectives Objectives Uses Uses Sedimentation Basins Sedimentation Basins Types of Settling Types of Settling Sedimentation.
Anaerobic Treatment The use of microbes in the absence of oxygen for the stabilization of organic material by conversion to methane, carbon dioxide, new.
Introduction to Environmental Engineering Dr. Kagan ERYURUK.
ENVE 420 Industrial Pollution Control FLOTATION (Ref: 1- WPCF – Wastewater Treatment Plant Design 2- Eckenfelder) Dr. Aslıhan Kerç.
Sludge Treatment CE 326 Principles of Environmental Engineering Department of Civil, Construction and Environmental Engineering Iowa State University Prof.
Wastewater Treatment By Samuel Lam. What is wastewater treatment Usually refer to sewage treatment, or domestic wastewater treatment process of removing.
FACTORING Think unfoil Work down, Show all steps ax 2 + bx + c.
Rainer Abendt Dr.- Ing. Rainer-Werner Abendt Nuremberg Contact: Wastewater Workshop in Nairobi 29-th August till 03-th September 2011.
Dr. Joel J. Ducoste, North Carolina State University, 1 Drinking Water Treatment Seminar Leesville Middle School Joel Ducoste Associate Professor Department.
Biological waste water treatment 1.It is a type of waste water treatment in which microorganisms such as bacteria are used to remove pollutants from waste.
Dr. Mohab Kamal. CE 445 Water Reclamation and Reuse (Dr. Mohab Kamal) 2.
Treatment of Slaughterhouse Wastewater Mike Lawrence NDSU Fall 2006.
(E6) Water Treatment Sarah Black. Background: About ¾ of the Earth’s surface is covered by water. Water is a polar substance capable of hydrogen bonding,
Chapter 11 Membrane Structure Essential Cell Biology Third Edition Copyright © Garland Science 2010.
1 Prof. Valter Bezerra Dantas
UNITED NATIONS Shipment Details Report – January 2006.
Domestic Waste Water Treatment. Composition of domestic sewage Human feces and urine – g of feces and liters of urine/person/day “graywater”
Dr. Malamis Dimitris National Technical University of Athens School of Chemical Engineering Unit of Environmental Science and Technology “ Water Resources.
Wastewater Treatment By Shantanu Mane Vaidehi Dharkar Viral Shah.
© 2017 SlidePlayer.com Inc. All rights reserved.