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行行年度年度泥 Iowa State University sung@iastate.edu

行行年度年度泥 (sludge/residuals) Sludge means any solids, semisolids or liquid wastes generated from a municipal, commercial, or industrial wastewater treatment plant, water supply treatment, or air pollution control facility or any other such waste having similar characteristics and effect. (US EPA)

行行年度年度Wastewater Treatment Plant

行行年度年度理泥來泥粒泥理泥泥理泥理泥泥

行行年度年度泥類來泥 (Primary Sludges, PS) 泥 (Biological sludges): 泥 (Waste Activated Sludges, WAS) Only PS and WAS are organic in nature which require further Stabilization/digestion 泥降泥 Alum sludges Iron sludges Lime sludges

年度行Typical Activated Sludge Treatment Plant Screens Preliminary treatment Grit Chamber Primary settling Activated sludge system Aeration basin Secondary settling Outlet PS 4 6% TS Anaerobic digester 20-35% TS Biogas Sludge Dewatering WAS 0.7-1.5% TS Sludge Thickening 4-8 % TS Energy production from biogas

行行年度年度Typical Sludge Concentrations Source Typical TS Concentrations % Primary sludge (PS) 3-6 Waste activated sludge (WAS) 0.7-1.5 Thickened sludge 4-8 Digested sludge 4-8 Dewatered sludge 20-35

行行年度年度Sludge Treatment and Disposal

年度行Importance of Sludge Treatment in Overall Wastewater Treatment Bar screen, Comminutor Grit chamber etc. Activated sludge, Trickling filter, RBC, etc. Domestic waste (100) Preliminary treatment (100) Primary sedimentation (65) Oxidized to CO 2 (30) Converted to sludge (35) Aerobic treatment Secondary sedimentation Effluent (10) Sludge treatment (60) Primary sludge (35) Secondary sludge (25)

行行年度年度Converting the organic in the sludge to more stable (inert) forms so they can be handled more easily (more dewaterable, less potential for odors) and used as soil conditioners. Typically stabilization involves anaerobic or aerobic digestion. During digestion considerable volatile solids destruction occurs 泥 Sludge Digestion

行行年度年度泥度 ph 量率

行行年度年度COMPLEX ORGANIC MATTERS Proteins Carbohydrates Lipids Amino Acids, Sugars Fatty Acids, Alcohols Intermediary Products (Organic acids: Propionic, Butyric acids, etc.) Acetate Hydrogen, Carbon dioxide Methane Carbon dioxide hydrolysis acidogenesis acetogenesis methanogenesis 72% 28% Organics Conversion in Anaerobic System

行行年度年度

行行年度年度率良率 SRT 數

行行年度年度single-stage high-rate digestion process

行行年度年度Two-Stage Digestion

行行年度年度Typical Design Criteria for Mesophilic Anaerobic Digesters PARAMETERS Solids Retention Time (HRT/SRT) 10 to 20 Solids Loading, lb VSS/ft 3 /day (Metcalf & Eddy) 0.15 to 0.40 Solids Loading, lb VSS/ft 3 /day (10 States Standards) 0.08 Combined Primary + Waste Biological (PS + WAS) Sludge Feed Concentration, % solids (dry basis) 4 to 6 Digester Underflow Concentration, % solids (dry basis) 4 to 6

行行年度年度率 VS Destruction 泥 VS COD 來泥 TS 率 40-50 泥 VS 率 40-70% 泥 20-50% 泥 VS 率 40-60 COD VS 不泥泥泥 SRT 率泥率 () 泥率

行行年度年度Sludge Type Effects

行行年度年度Initial Volatile Solid Content Effects

行行年度年度Temperature Effects

行行年度年度1 CH4 + 2 O2 CO2 + 2 H2O 1 mole CH 4 = 22.4 Liter at STP 2 mole O 2 = 2 x 32 g/mole = 64 g O 2 22.4 L H 2 / 64 g O 2 = 0.35 L CH4/g COD In anaerobic environment, there is no other way to remove COD but produce CH 4. Assume: 1g VS (sludge) = 1.5 ~ 2.0 g COD Then, 1g VS destructed could produce 1.5 x 0.35 2.0 x 0.35 ( 0.53 0.7 L CH 4 ) 1 kg VS destructed 0.53 0.7 m 3 of CH 4 Theoretical Methane Production Calculations

行行年度年度 + + + 3 ) 3( 2 2 2 1 HCO H CO H O H CO H K a aq K + + 2 3 2 3 CO H HCO Ka K a1 : 6.381@20 K a2 : 10.377@20 Biogas Content CH 4 + CO 2 + N 2 + Trace H 2 S

行行年度年度不流量度流度累度 ph 量例率降 SRT 量度 ph 量率

行行年度年度不泥良狀不度 NH 4, SS BOD 泥不易良泥良不惡

行行年度年度 1000 mg/l 泥 VS (C 10H 19N0 3) 200 mg CaCO 3 /L 度類流離 CO 2 H 2 O HCO 3- 度來若量泥度度 VFA and ALK

行行年度年度 HCO 3 - + HAc >H 2 O + CO 2 + Ac - 度更 ph 降 ph 6.8-7.2 度 ~5,000 mg/l ph CaCO 3 \Na 2 CO 3 NaOH NH 3 度 VFA and ALK

行年度COD Sample Parameters Test Frequency Influent TS/VS, TSS/VSS, COD Once a week Effluent TS/VS, TSS/VSS, VFA, Twice a week starting the 2 nd week Start-up Monitoring Program NH 4 -N Once a week Mixed liquor VFA Daily for the first week starting on the 2 nd day and every other day after first week ph Everyday Biogas Gas production Daily CH 4 /CO 2 /N 2 Once a week starting in the 2 nd week Temperatur e C Daily

行行年度年度Conditions: 1. Low ph: ph < 6.8 due to VFA accumulation in the system 2. No biogas production: methanogenesis ceased 3. High VFA: VFA > 1,500 mg/l as acetic acid 4. Low temperature: temperature < 30 C (optimum: 35 C) Conditions Solutions 1 only Reduce daily loads + NaHCO 3 or lime addition 2 only Check for leakage. If no leak, reduce loading & wait 3 only Stop feeding. If VFA > 2,000 mg/l, then add dilution water 4 only Heat addition depending on the system 1 + 2 Reduce daily loads and wait; lime addition might be warranted 1 + 3 Stop feeding and add dilution water Trouble Shooting

行行年度年度料 04-23504558 04-23595761 行行行年度年度