Enhanced Anaerobic Digestion of Sewage Sludge by Addition of Food Waste

2013 ◽  
Vol 777 ◽  
pp. 139-142
Author(s):  
Li Han ◽  
Ru Ying Li ◽  
Min Ji
Keyword(s):  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
Removal Efficiency ◽  
Food Waste ◽  
Methane Yield ◽  
Anaerobic Sludge ◽  
Sludge Digestion ◽  
Vs Removal ◽  
Anaerobic Sludge Digestion ◽  
Mesophilic Condition

In order to improve the methane yield and removal efficiency of organic matters in anaerobic sludge digestion, effects of addition of food waste were investigated at mesophilic condition. Results showed that the optimal TS ratio between sewage sludge and food waste was 4:1, with a methane yield of 592.7 ml/g-VS, methane content of 66.84% and the VS removal efficiency of 31%, which were 47%, 50% and 55% higher than those of sole sludge digestion, respectively.

Ozonation of sewage sludge prior to anaerobic digestion

2000 ◽  
Vol 42 (9) ◽  
pp. 175-178 ◽  
Author(s):  
M. Weemaes ◽  
H. Grootaerd ◽  
F. Simoens ◽  
A. Huysmans ◽  
W. Verstraete
Keyword(s):  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
Anaerobic Sludge ◽  
Waste Sludge ◽  
Sludge Digestion ◽  
Novel Approach ◽  
Sediment Fraction ◽  
Anaerobic Sludge Digestion ◽  
Pre Treatment ◽  
Rate Limiting

Anaerobic digestion has traditionally been employed to reduce the mass and volume of waste sludge and to enhance the sludge dewaterability. In practice, anaerobic digestion of biosolids has a number of shortcomings, i.e. the low biodegradability of the microbial cells and the high retention times due to the rate limiting hydrolysis step. An oxidative sludge pre-treatment with ozone was therefore used to solubilize the organic compounds and increase their biodegradability. It is shown that the pre-treatment could significantly enhance anaerobic sludge digestion. Moreover, a novel approach in which the sludge was separated in a thickened sediment fraction and a supernatant was investigated. The sediment was digested anaerobically and the supernatant was treated aerobically. The overall COD-removal efficiency of the biosolids was 72%.

scholarly journals Enhancement of performance and biodegradability kinetics of aerobic-anaerobic sludge digestion

2020 ◽  
Vol 167 ◽  
pp. 01010 ◽  
Author(s):  
Boonchai Wichitsathian ◽  
Jareeya Yimratanabovorn ◽  
Watcharapol Wonglertarak
Keyword(s):  
Organic Matter ◽  
Removal Efficiency ◽  
Aeration Rate ◽  
Anaerobic Sludge ◽  
Sludge Reduction ◽  
Excess Sludge ◽  
Sludge Digestion ◽  
Anaerobic Sludge Digestion ◽  
Aerobic Sludge ◽  
Biodegradable Organic Matter

The excess sludge problem from a wastewater treatment plant is a great concerned due to the high cost of sludge management accounting for about 20% to 50% of the total operating cost. Therefore, sludge reduction is critical. Currently, aerobic and/or anaerobic sludge digestions are widely used in the industries for treating the excess sludge. The objective of this research was to study the effects of aeration rate and temperature on the excess sludge reduction by using the aerobic-anaerobic digestion system in the laboratory. The aeration rates of 1.0, 0.5, and 0.1 volume air per volume slurry per minute (vvm) at the room temperature and the thermophilic temperature (55 ± 2°C) were investigated. The results showed that the highest removal efficiency of aerobic sludge digestion was obtained at the thermophilic temperature and aeration rate of 1.0 vvm. The removal efficiency of organic matter in terms of COD, total solids (TS) and volatile solids (VS) were 34.76%, 33.01% and 43.45%, respectively. Consequently, the highest specific growth rate of microorganisms was 0.39 per hour and the substrate removal rate was 0.55 milligram CODremoved per milligram VSS per hour. Furthermore, slowly biodegradable organic matter was hydrolyzed to readily biodegradable organic matter and inert soluble organic matter. When the sludge effluent from aerobic sludge digestion was feed to the anaerobic sludge digestion, the removal efficiency of organic matter in terms of COD, TS and VS were increased by 25%, 17% and 28%, respectively. Moreover, the obtained methane production rate in the anaerobic sludge digestion was approximate 0.234 m3/kg COD removed.

Energy self-sufficient sewage wastewater treatment plants: is optimized anaerobic sludge digestion the key?

2013 ◽  
Vol 68 (8) ◽  
pp. 1739-1744 ◽  
Author(s):  
P. Jenicek ◽  
J. Kutil ◽  
O. Benes ◽  
V. Todt ◽  
J. Zabranska ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Energy Consumption ◽  
Anaerobic Digestion ◽  
Biogas Production ◽  
Treatment Plant ◽  
Anaerobic Sludge ◽  
Waste Activated Sludge ◽  
Sludge Digestion ◽  
Anaerobic Sludge Digestion ◽  
Standard Energy

The anaerobic digestion of primary and waste activated sludge generates biogas that can be converted into energy to power the operation of a sewage wastewater treatment plant (WWTP). But can the biogas generated by anaerobic sludge digestion ever completely satisfy the electricity requirements of a WWTP with ‘standard’ energy consumption (i.e. industrial pollution not treated, no external organic substrate added)? With this question in mind, we optimized biogas production at Prague's Central Wastewater Treatment Plant in the following ways: enhanced primary sludge separation; thickened waste activated sludge; implemented a lysate centrifuge; increased operational temperature; improved digester mixing. With these optimizations, biogas production increased significantly to 12.5 m3 per population equivalent per year. In turn, this led to an equally significant increase in specific energy production from approximately 15 to 23.5 kWh per population equivalent per year. We compared these full-scale results with those obtained from WWTPs that are already energy self-sufficient, but have exceptionally low energy consumption. Both our results and our analysis suggest that, with the correct optimization of anaerobic digestion technology, even WWTPs with ‘standard’ energy consumption can either attain or come close to attaining energy self-sufficiency.

scholarly journals Performance and Kinetic Model of a Single-Stage Anaerobic Digestion System Operated at Different Successive Operating Stages for the Treatment of Food Waste

Processes ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 600 ◽  
Author(s):  
Sagor Kumar Pramanik ◽  
Fatihah Binti Suja ◽  
Mojtaba Porhemmat ◽  
Biplob Kumar Pramanik
Keyword(s):  
Experimental Data ◽  
Anaerobic Digestion ◽  
Kinetic Model ◽  
Removal Efficiency ◽  
Food Waste ◽  
Biogas Production ◽  
Gompertz Model ◽  
Methane Yield ◽  
Biogas Yield ◽  
Modified Gompertz Model

A large quantity of food waste (FW) is generated annually across the world and results in environmental pollution and degradation. This study investigated the performance of a 160 L anaerobic biofilm single-stage reactor in treating FW. The reactor was operated at different hydraulic retention times (HRTs) of 124, 62, and 35 days under mesophilic conditions. The maximum biogas and methane yield achieved was 0.934 L/g VSadded and 0.607 L CH4/g VSadded, respectively, at an HRT of 124 days. When HRT decreased to 62 days, the volatile fatty acid (VFA) and ammonia accumulation increased rapidly whereas pH, methane yield, and biogas yield decreased continuously. The decline in biogas production was likely due to shock loading, which resulted in scum accumulation in the reactor. A negative correlation between biogas yield and volatile solid (VS) removal efficiency was also observed, owing to the floating scum carrying and urging the sludge toward the upper portion of the reactor. The highest VS (79%) and chemical oxygen demand (COD) removal efficiency (80%) were achieved at an HRT of 35 days. Three kinetic models—the first-order kinetic model, the modified Gompertz model, and the logistic function model—were used to fit the cumulative biogas production experimental data. The kinetic study showed that the modified Gompertz model had the best fit with the experimental data out of the three models. This study demonstrates that the stability and performance of the anaerobic digestion (AD) process, namely biogas production rate, methane yield, intermediate metabolism, and removal efficiency, were significantly affected by HRTs.

scholarly journals Recognition of the key chemical constituents of sewage sludge for biogas production

RSC Advances ◽  
2017 ◽  
Vol 7 (4) ◽  
pp. 2033-2037 ◽  
Author(s):  
Xiaohu Dai ◽  
Ying Xu ◽  
Yiqing Lu ◽  
Bin Dong
Keyword(s):  
Organic Matter ◽  
Sewage Sludge ◽  
Silica Particle ◽  
Biogas Production ◽  
Chemical Constituents ◽  
Anaerobic Sludge ◽  
Key Factors ◽  
Sludge Digestion ◽  
Anaerobic Sludge Digestion ◽  
Biodegradable Organic Matter

The easy biodegradable organic matter, non-biodegradable organic matter, metal ions, and micron-sized silica particle and their interactions were the key factors for limiting the biogas production from anaerobic sludge digestion.

scholarly journals THE IMPACT OF CHEMICAL PHOSPHORUS REMOVAL ON THE PROCESS OF ANAEROBIC SLUDGE DIGESTION

2010 ◽  
Vol 2 (5) ◽  
pp. 71-74
Author(s):  
Svetlana Ofverstrom ◽  
Ieva Sapkaitė ◽  
Regimantas Dauknys
Keyword(s):  
Anaerobic Digestion ◽  
Phosphorus Removal ◽  
Biogas Production ◽  
Anaerobic Sludge ◽  
Primary Sludge ◽  
Sludge Digestion ◽  
Volatile Solids ◽  
Anaerobic Sludge Digestion ◽  
Gas Volume ◽  
The Impact

The paper investigates the efficiency of the mixture of primary sludge and excess activated sludge in Vilnius WWTP with reference to the anaerobic digestion process. Sludge digestion was carried out under laboratory conditions using anaerobic sludge digestion model W8 (Armfield Ltd., UK). Laboratory analyses consist of two periods – the anaerobic digestion of the un-dosed and Fe-dosed sludge mixture. The results of digestion were processed using the methods of statistical analysis. The findings showed reduction in volatile solids approx. by 6% when dosing min FeCl3·6H2O and 15% when dosing max FeCl3·6H2O into feed sludge. Gas volume produced during the digestion of the un-dosed sludge was 90–160 ml/d and 60–125 ml/d in min Fe-dosed sludge and 45-95 ml/d. Also, correlation between VS loadings and biogas production was found. A rise in VS loading from 0,64 g/l/d to 1,01 g/l/d increased biogas production from 90 ml/d to 140–160 ml/d.

Aerobic Thermophilic Stabilization of Sludge versus Anaerobic Digestion and Other Kinds of Sludge Treatment at Middle-Sized Plants with Respect to Power Conservation and Economy

1982 ◽  
Vol 14 (6-7) ◽  
pp. 727-738
Author(s):  
P Wolf
Keyword(s):  
Anaerobic Digestion ◽  
Economic Benefit ◽  
Energy Recovery ◽  
Sewage Treatment Plant ◽  
Anaerobic Sludge ◽  
Process Conditions ◽  
Sludge Treatment ◽  
Capital Costs ◽  
Sludge Digestion ◽  
Anaerobic Sludge Digestion

Operating data concerning energy balances are collected by a state bureau from a sewage treatment plant with aerobic–thermophilic stabilization and also from plants with anaerobic sludge digestion and energy recovery. On the basis of this data power and heat balances as well as cost–benefit–calculations have been obtaineu for treatment plants of different sizes with different biological and sludge treatment processes. In spite of high and rising energy costs in plants utilizing the aerobic-thermophilic stabilization process the results show an overall economic benefit for this process at small and middle-sized treatment plants compared to those utilizing anaerobic sludge digestion. The evaluation of data indicates that this economic benefit is due to high capital costs and little efficiency of energy recovery under process conditions at small and middle-sized plants applying anaerobic digestion.

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