Full-scale application of focused-pulsed pre-treatment for improving biosolids digestion and conversion to methane

2008 ◽  
Vol 58 (10) ◽  
pp. 1895-1901 ◽  
Author(s):  
Bruce E. Rittmann ◽  
Hyung-sool Lee ◽  
Husen Zhang ◽  
Jared Alder ◽  
James E. Banaszak ◽  
...  
Keyword(s):  
Biogas Production ◽  
Gas Production ◽  
Full Scale ◽  
Waste Sludge ◽  
Sludge Digestion ◽  
Secondary Sludge ◽  
Most Significant Change ◽  
Bacterial And Archaeal Communities ◽  
Pre Treatment ◽  
Archaeal Communities

We tested at full-scale the innovative Focused Pulsed (FP) technology for pre-treating waste sludge in order to improve methane gas production and biosolids reduction in sludge digestion, but without incurring problems of odors, toxicity, and high costs for chemical or energy consumption. FP pre-treatment of a mixture of primary and secondary sludge increased the soluble COD by 160% and DOC 120% over the control. FP pre-treatment of 63% of the input waste sludge increased biogas production by over 40% and reduced biosolids requiring disposal by 30% when compared to the plant baseline. FP pre-treatment also correlated with a shift of the bacterial and archaeal communities. The most significant change was that the acetate-cleaving Methanosaeta became the dominant methanogen. Full FP pre-treatment should increase biogas production and biosolids removal by 60% and 40%, respectively. Full FP pre-treatment should generate energy benefits of at least 2.7 times and as high as 18 times the FP energy input, depending on heat recovery from FP treatment. For a plant treating 76,000 m3/d of wastewater (380 m3-sludge/d), FP treatment should generate an annual economic benefit of approximately $540,000 net of electricity and other operating and maintenance costs. This represents a payback period of three years or less.

Full-stream and part-stream ultrasound treatment effect on sludge anaerobic digestion

2010 ◽  
Vol 61 (6) ◽  
pp. 1363-1372 ◽  
Author(s):  
S. I. Pérez-Elvira ◽  
L. C. Ferreira ◽  
A. Donoso-Bravo ◽  
M. Fdz-Polanco ◽  
F. Fdz-Polanco
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Full Scale ◽  
Optimum Process ◽  
Capillary Suction ◽  
Biogas Yield ◽  
Batch Tests ◽  
Secondary Sludge ◽  
Pre Treatment ◽  
The Relationship

The use of ultrasound as pre-treatment to improve anaerobic digestion of secondary sludge has been established as a promising technology. There are great differences between lab scale and full-scale devices, regarding the relationship between the disintegration achieved and the energy supplied. Based on economic aspects, most of the full-scale plants use partial-stream instead of the full-stream sonication, which affects biogas production and digestate dewatering characteristics. A laboratory scale operation combining ultrasound and anaerobic digestion (batch tests) has been performed, determining the relationship between the ratio of sonicated sludge fed and the methane production, SCOD removal and capillary suction time after 20-day anaerobic biodegradation, in order to check the possible benefits of part-stream versus full-stream sonication. Additional incubation was also evaluated, searching for an optimum process combining ultrasound and 24-h incubation pretreatment. Results showed that by sonicating fresh WAS at 25,700 kJ/kg TS biogas yield increased linearly with the percentage of sonicated WAS in the substrate, from 248 (control reactor) to 349 mL CH4/g VS (41% increase in full-stream sonication). By incubation (24 h, 55°C), 325 mL CH4/g VS were obtained (31% increase), but the digestion of the soluble compounds generated during incubation of sonicated sludge appeared to be less degradable compared to those solubilised by ultrasound or incubation alone, which showed no benefit in combining both treatments. Post-digestion dewatering deteriorated for both part-stream and full-stream sonication, and CST values were constant (74% higher than the control digestate) from 30% to 100% sonicated sludge.

Increased Stability of Anaerobic Digestion by Controlled Recirculation

1991 ◽  
Vol 23 (7-9) ◽  
pp. 1229-1237
Author(s):  
Chaio-Fuei Ouyang ◽  
Tain-Gen Chang
Keyword(s):  
Substantial Reduction ◽  
Gas Production ◽  
Digested Sludge ◽  
Significant Saving ◽  
Methane Generation ◽  
Sludge Digestion ◽  
Solids Concentration ◽  
Secondary Sludge ◽  
Sludge Recycling ◽  
Growth System

The treatment characteristics of municipal sludge were investigated by the anaerobic activated sludge digestion (AASD) system. This study used the suspended growth system and mesophilic temperature in the digestors and separators; the system achieves a more stable and improved process; such a process configuration offers the possibility of a substantial reduction in the total volume necessary for efficient stabilization. This study presents data indicating that the AASS system is feasible. In general, with an applied solids concentration of TS= 2%, the nonbiodegradable portion of the substrate concentration contained in the primary and secondary sludge was found to be 40.6% and 35.1% on the basis or TVS and COD, respectively. This study also provides evidence that the reactions at a recycling ratio of R=1 and R=3 are considerably more stable than those achieved in conventional or other recycling ratio digestors with a HRT of 9 days or longer. The gas production and bioactivity is also higher than that normally produced by the conventional single-stage digestion system. The experimental results also indicate that the dilution rate exceeds the maximum specific growth rate as the HRT is decreased from 9 days to 6 days. The significant saving in reactor volume and enhanced methane generation should offset the energy required for digested sludge recycling.

Swine manure biogas production improvement using pre-treatment strategies: lab-scale studies and full-scale application

2021 ◽  
pp. 100716
Author(s):  
Deisi Cristina Tápparo ◽  
Daniela Cândido ◽  
Ricardo Luis Radis Steinmetz ◽  
Christian Etzkorn ◽  
André Cestonaro do Amaral ◽  
...  
Keyword(s):  
Biogas Production ◽  
Swine Manure ◽  
Treatment Strategies ◽  
Full Scale ◽  
Production Improvement ◽  
Pre Treatment

scholarly journals Microbiome of Seven Full-Scale Anaerobic Digestion Plants in South Korea: Effect of Feedstock and Operational Parameters

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 665
Author(s):  
Michal Sposob ◽  
Hee-Sung Moon ◽  
Dongjin Lee ◽  
Yeo-Myeong Yun
Keyword(s):  
Microbial Population ◽  
Ammonium Nitrogen ◽  
H2 Production ◽  
Full Scale ◽  
Organic Loading Rate ◽  
Operational Parameters ◽  
Sludge Digestion ◽  
Secondary Sludge ◽  
Potential Activity ◽  
Total Ammonium

In this study, the microbiomes linked with the operational parameters in seven mesophilic full-scale AD plants mainly treating food waste (four plants) and sewage sludge (three plants) were analyzed. The results obtained indicated lower diversity and evenness of the microbial population in sludge digestion (SD) plants compared to food digestion (FD) plants. Candidatus Accumulibacter dominated (up to 42.1%) in SD plants due to microbial immigration from fed secondary sludge (up to 89%). Its potential activity in SD plants was correlated to H2 production, which was related to the dominance of hydrogenotrophic methanogens (Methanococcus). In FD plants, a balance between the hydrogenotrophic and methylotrophic pathways was found, while Flavobacterium and Levilinea played an important role during acidogenesis. Levilinea also expressed sensitivity to ammonia in FD plants. The substantial differences in hydraulic retention time (HRT), organic loading rate (OLR), and total ammonium nitrogen (TAN) among the studied FD plants did not influence the archaeal methane production pathway. In addition, the bacterial genera responsible for acetate production through syntrophy and homoacetogenesis (Smithella, Treponema) were present in all the plants studied.

Molecular characterization of bacterial and archaeal communities in a full-scale anaerobic reactor treating corn straw

2013 ◽  
Vol 143 ◽  
pp. 512-518 ◽  
Author(s):  
Jiang-Tao Qiao ◽  
Yan-Ling Qiu ◽  
Xian-Zheng Yuan ◽  
Xiao-Shuang Shi ◽  
Xiao-Hui Xu ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Full Scale ◽  
Corn Straw ◽  
Anaerobic Reactor ◽  
Bacterial And Archaeal Communities ◽  
Archaeal Communities

scholarly journals Evaluation of acidogenic sludge from anaerobic reactors running at low solids retention times to reduce sludge generation and enhance biogas production

Water SA ◽  
2019 ◽  
Vol 45 (4 October) ◽  
Author(s):  
Wilza Da Silva Lopes ◽  
Ysa Helena Diniz Morais de Luna ◽  
Jose Tavares de Sousa ◽  
Wilton Silva Lopes ◽  
Valderi Duarte Leite
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Kinetic Constant ◽  
Oxygen Demand ◽  
Gas Production ◽  
Primary Sludge ◽  
Anaerobic Reactors ◽  
Solids Retention ◽  
Improved Performance ◽  
Pre Treatment

ABSTRACT   Sludges generated in the biological processing of sewage are complex mixtures, the constituents of which pose risks to public health and the environment. Anaerobic digestion is considered the most sustainable option for treating sludge because it offers the possibility of generating biogas. The aim of this study was to compare the quantities, properties, biodegradabilities and biochemical methane potentials (BMP) of primary sludge (PS) generated by a primary decanter with acidogenic sludges produced by upflow anaerobic (UA) reactors operating at solids retention times (SRTs) of 2, 4, 6 and 8 days (Samples S2, S4, S6 and S8, respectively). Sludges from both pre-treatments were submitted to alkaline solubilization in order to determine the efficiency of the process in disrupting extracellular complexes. Based on the levels of total solids (TS) present, the primary decanter was found to generate higher quantities of excess sludge (yield of 3.1 gTS∙d-1) than UA reactors operating at low SRTs (yields in the range 1.69 to 0.64 gTS∙d-1). The concentrations of dissolved materials in PS and Samples S2 and S8 were considerably higher after alkaline solubilization, with respective increases of 8, 14 and 28-fold in dissolved organic carbon, 12, 20 and 40-fold in chemical oxygen demand, 25, 31 and 59-fold in proteins, and 17, 21 and 63-fold in carbohydrates. In addition, the BMP value for S8 was some 13% higher than that recorded for PS while the kinetic constant for gas production by S8 was 1.8-fold greater than that of PS. It is concluded that a pre-treatment combining anaerobic digestion at low SRT and alkaline solubilisation would lead to improved performance in subsequent stages of anaerobic digestion and, consequently, increased efficiency in biogas production.

scholarly journals Anaerobic Digestion of Steam-Exploded Wheat Straw and Co-Digestion Strategies for Enhanced Biogas Production

2020 ◽  
Vol 10 (22) ◽  
pp. 8284
Author(s):  
Fokion Kaldis ◽  
Denise Cysneiros ◽  
James Day ◽  
Kimon-Andreas G. Karatzas ◽  
Afroditi Chatzifragkou
Keyword(s):  
Anaerobic Digestion ◽  
Wheat Straw ◽  
Steam Explosion ◽  
Biogas Production ◽  
Inorganic Nitrogen ◽  
Rapeseed Meal ◽  
Gas Production ◽  
Distillers Grains With Solubles ◽  
Dried Distillers Grains ◽  
Pre Treatment

Wheat straw (WS) is considered a favourable substrate for biogas production. However, due to its rigid structure and high carbon to nitrogen (C/N ratio), its biodegradability during anaerobic digestion (AD) is usually low. In the present study, the effect of steam explosion pre-treatment on WS, combined with C/N adjustment with inorganic nitrogen, on biogas production was evaluated. Additionally, co-digestion of WS with protein-rich agri-industrial by-products (dried distillers’ grains with solubles (DDGS) and rapeseed meal (RM)) was assessed. Steam explosion enhanced biogas production from WS, whereas the addition of NH4Cl was beneficial (p < 0.05) for the digestion of steam-exploded wheat straw (SE). Furthermore, mono-digestion of the four different substrates seemed to be efficient in both inoculum to substrate ratios (I/S) tested (3.5 and 1.75 (w/w)). Finally, during co-digestion of WS and SE with DDGS and RM, an increase in the cumulative methane production was noted when higher amounts of DDGS and RM were co-digested. This study demonstrated that DDGS and RM can be used as an AD supplement to stimulate gas production and improve wheat straw biodegradability, while their addition at 10% on an AD system operating with WS can enhance gas yields at levels similar to those achieved by steam-exploded straw.

scholarly journals Nitrogen in the Process of Waste Activated Sludge Anaerobic Digestion

2014 ◽  
Vol 40 (2) ◽  
pp. 123-136 ◽  
Author(s):  
Jan Suschka ◽  
Klaudiusz Grübel
Keyword(s):  
Anaerobic Digestion ◽  
Activated Sludge ◽  
Biogas Production ◽  
Sewage Treatment ◽  
Anaerobic Treatment ◽  
Waste Activated Sludge ◽  
Sludge Digestion ◽  
Sludge Pretreatment ◽  
Negative Side Effects ◽  
Pre Treatment

Abstract Primary or secondary sewage sludge in medium and large WWTP are most often processed by anaerobic digestion, as a method of conditioning, sludge quantity minimization and biogas production. With the aim to achieve the best results of sludge processing several modifications of technologies were suggested, investigated and introduced in the full technical scale. Various sludge pretreatment technologies before anaerobic treatment have been widely investigated and partially introduced. Obviously, there are always some limitations and some negative side effects. Selected aspects have been presented and discussed. The problem of nitrogen has been highlighted on the basis of the carried out investigations. The single and two step - mesophilic and thermophilic - anaerobic waste activated sludge digestion processes, preceded by preliminary hydrolysis were investigated. The aim of lab-scale experiments was pre-treatment of the sludge by means of low intensive alkaline and hydrodynamic disintegration. Depending on the pretreatment technologies and the digestion temperature large ammonia concentrations, up to 1800 mg NH4/dm3 have been measured. Return of the sludge liquor to the main sewage treatment line means additional nitrogen removal costs. Possible solutions are discussed.

Evaluation of the reject waters from co-digestion of solid wastes from agro-industries in a municipal WWTP

2007 ◽  
Vol 55 (10) ◽  
pp. 37-44 ◽  
Author(s):  
O. Nowak ◽  
R. Melcher ◽  
P. Enderle
Keyword(s):  
Methane Production ◽  
Biogas Production ◽  
Ammonia Nitrogen ◽  
Organic Wastes ◽  
Nitrogen Loading ◽  
Mass Balances ◽  
Leather Industry ◽  
Anaerobic Digesters ◽  
Waste Sludge ◽  
Sludge Digestion

Overcapacities of anaerobic digesters at municipal WWTPs are frequently used for the treatment of organic wastes in order to increase the biogas production. However, “co-digestion” of organic wastes leads to additional nitrogen loading and to additional loads of non-biodegradable COD. The effects of (co-) digestion of organic wastes from agro-industries (slaughterhouses, dairies and leather industry) on the wastewater cycle have been evaluated in full-scale investigations at Leoben WWTP with a capacity of 90,000 pe where the methane production was increased from 700 to more than 1,700 Nm3 CH4 per day. For this evaluation, mass balances for COD and nitrogen have been applied to estimate the fluxes of these substances. Application of this method is described in detail. As the additional loadings, it was found that related to methane production less nitrogen is released from the organic wastes than from the waste sludge. While the ammonia nitrogen load in the effluent from sludge digestion was about 100 g NH4-N per Nm3 of CH4 produced, in the effluent from the digestion of organic wastes only 70 g NH4-N/Nm3 CH4 were found. The decrease in the COD removal efficiency after digestion of the organic wastes started was not regarded as significant enough to be seen as a consequence of the treatment of external substrate.

scholarly journals Variation of the digester temperature in the annual cycle – using the digester as heat storage

2019 ◽  
Vol 14 (2) ◽  
pp. 471-481 ◽  
Author(s):  
C. Hubert ◽  
B. Steiniger ◽  
C. Schaum ◽  
M. Michel ◽  
M. Spallek
Keyword(s):  
Organic Acid ◽  
Heat Storage ◽  
Biogas Production ◽  
Total Concentration ◽  
Temperature Fluctuations ◽  
Gas Production ◽  
Full Scale ◽  
Production Performance ◽  
Process Stability ◽  
Significant Difference

Abstract Regarding digesters, present guidelines assume that the temperature must be kept constant in order to achieve process stability and that there is a drop in gas production between 40 and 50 °C. Nevertheless, observations of full-scale application show that fluctuations in temperature between mesophilic and thermophilic environments is indeed possible without any loss in biogas production performance. This would be particularly favourable because the digester can thus act as a heat storage. In order to validate temperature fluctuations on full-scale digesters the data of two digesters from different wastewater treatment plants (WWTPs) with high temperature fluctuations were analyzed. In addition, chemical oxygen demand (COD) balances for different temperature ranges were conducted in order to evaluate the process stability. The results show that fluctuations between mesophilic and thermophilic conditions can be achieved without a decrease in biogas production. Increasing the temperature above 50 °C leads to an increase in organic acid concentration as described in the literature. Nevertheless, the total concentration of organic acid was still at an uncritical level below 500 mg/L. The COD balance shows no significant difference between 38 °C, 44 °C and 51 °C. The rate of temperature fluctuations per day specifically seems to be a main factor for process stability rather than temperature itself.

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