Semi-continuous anaerobic digestion of food waste using a hybrid anaerobic solid-liquid bioreactor

2003 ◽  
Vol 48 (4) ◽  
pp. 169-174 ◽  
Author(s):  
J.-Y. Wang ◽  
H.-L. Xu ◽  
H. Zhang ◽  
J.-H. Tay
Keyword(s):  
Anaerobic Digestion ◽  
Solid Waste ◽  
Food Waste ◽  
Biogas Production ◽  
Continuous Operation ◽  
Methane Content ◽  
High Rate ◽  
Uasb Reactor ◽  
Two Phase ◽  
Solid Liquid

A hybrid anaerobic solid-liquid (HASL) bioreactor was developed to enhance food waste conversion. The HASL bioreactor is a modified two-phase anaerobic digestion system with a solid waste reactor and a high-rate anaerobic wastewater reactor, which was a UASB reactor. In this study, the methanogenesis in the UASB reactor was investigated under a semi-continuous operation of the food waste digestion system. The HASL process, including 7 days of start-up and 23 days of semi-continuous operation followed by 6 days of batch operation, was commenced by loading 2.8 kg of shredded food waste. During the semi-continuous operation, 0.2 kg of the same waste was loaded daily. The leachate from acidification phase, i.e., solid waste reactor, remained acidic (pH 4.9-5.5) and high in total VFA (TVFA), 9,500-11,500 mg/L, and COD (8,000-11,800 mg/L) levels. In the methanogenesis phase, i.e., UASB reactor, effective TVFA and COD removals (88 ± 5% and 85 ± 7%, respectively) were obtained, while the methane content was 71%. At the end of operation, about 78% of VS added in the HASL bioreactor was removed, while TOC and total COD reductions were 78% and 79%, respectively. The results showed that the use of UASB reactor in the semi-continuous HASL system can enhance the methanogenesis process and increase the methane content in biogas production.

A comparative study of anaerobic digestion of food waste in a single pass, a leachate recycle and coupled solid/liquid reactors

2003 ◽  
Vol 47 (1) ◽  
pp. 319-324 ◽  
Author(s):  
H.L. Xu ◽  
J.Y. Wang ◽  
H. Zhang ◽  
J.H. Tay
Keyword(s):  
Anaerobic Digestion ◽  
Food Waste ◽  
Methane Content ◽  
Anaerobic Sludge ◽  
Methane Fermentation ◽  
Two Phase ◽  
Single Pass ◽  
Digestion Process ◽  
Solid Liquid ◽  
Methanogenic Phase

A single pass reactor (R1), a leachate recycle reactor (R2) and a coupled solid/liquid bioreactor (R3-Rm) for anaerobic digestion of food waste were comparatively investigated in terms of digestion process and treatment efficiency. The coupled solid/liquid bioreactor is an enhanced two-phase system and distinctive from a traditional two-phase process with an upflow anaerobic sludge blanket (UASB) reactor as the methanogenic phase and a circulation of treated leachate between the acidification and methanogenic phases. In comparison with R1 and R2, R3-Rm enhanced the digestion process and increased the methane content of biogas. 100% of the R3-Rm methane yield was from the methanogenic phase with average methane content of 71%. The significant enhancement was also confirmed by the removal of 79% of total organic carbon (TOC), 60% of volatile solids (VS) and 80% of total COD in 12 days running of R3-Rm. However, no active methane fermentation was detected in R1 and R2 during 60 days operation. The results in this laboratory-scale study show that the rapid accumulation of volatile fatty acids (VFAs) due to the rapid acidification of food waste inhibits the development of effective methane fermentation in single pass and leachate recycle reactors. The coupled solid/liquid bioreactor is more efficient in converting food waste into methane and carbon dioxide.

Towards new indicators for the prediction of solid waste anaerobic digestion properties

2006 ◽  
Vol 53 (8) ◽  
pp. 233-241 ◽  
Author(s):  
P. Buffiere ◽  
D. Loisel ◽  
N. Bernet ◽  
J-P. Delgenes
Keyword(s):  
Anaerobic Digestion ◽  
Solid Waste ◽  
Biochemical Composition ◽  
Anaerobic Degradation ◽  
Biogas Production ◽  
Methane Content ◽  
Methane Potential

The biochemical composition can be seen as a good indicator of both the biodegradability and the methane potential of a given waste. The work presented here is an attempt to elaborate a typology of wastes and to compare it to the anaerobic degradation characteristics. The first data indicate that there is a link between the ligno-cellulosic content of the waste and the biodegradability. When dealing with application to anaerobic digestion processes, having a tool to predict the ability of the waste to be degraded could be of the greatest interest for preventing failures, estimating biogas production, methane content, or for the management of co-digestion processes.

Anaerobic digestion of solid waste: state-of-the-art

2000 ◽  
Vol 41 (3) ◽  
pp. 283-290 ◽  
Author(s):  
L. De Bere
Keyword(s):  
Anaerobic Digestion ◽  
Solid Waste ◽  
Dry Matter ◽  
State Of The Art ◽  
Biogas Production ◽  
High Rate ◽  
Household Waste ◽  
Dry Digestion ◽  
Phase Systems ◽  
Under Construction

In order to make a correct assessment of the state-of-the-art of the technology, a study was made on the development of digestion capacity for solid waste in Europe. The study was limited to plants in operation or under construction that were treating at least 10% organic solid waste coming from market waste or municipal solid waste. A total treatment capacity for solid waste organics, excluding the tonnage used for sewage sludge and manures, evolved from 122,000 ton per year in 1990 to 1,037,000 ton available or under construction by the year 2000 in 53 plants across Europe, an increase by 750%. Both mesophilic and thermophilic technologies have been proven, with about 62% of capacity being operated at mesophilic temperatures. Wet and dry digestion are almost evenly split, while a clear choice was made for one-phase systems instead of two-phase systems, which represent only 10.6% of capacity. The capacity provided by co-digestion systems is limited, while there is a rising interest in digestion of mixed household waste. The reliable performance has been demonstrated for all types of anaerobic digestion systems. On the basis of the Dranco technology, a single-phase thermophilic dry digestion process, performances were reached similar to high-rate wastewater digestion. An annual average loading rate of 18.5 kg COD/m3.day, resulting in a biogas production of 9.2 m3/m3reactor.day was obtained at a full-scale plant. The plant operated at a retention time of 15.3 days. Feedstocks range from clean organic wastes (31% dry matter) to heavily polluted grey waste organics (57% dry matter). Average dry matter concentrations of the digested residue of 41% were obtained.

High-calorific biogas production from anaerobic digestion of food waste using a two-phase pressurized biofilm (TPPB) system

2017 ◽  
Vol 224 ◽  
pp. 56-62 ◽  
Author(s):  
Yeqing Li ◽  
Hong Liu ◽  
Fang Yan ◽  
Dongfang Su ◽  
Yafei Wang ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Food Waste ◽  
Biogas Production ◽  
Two Phase

A hybrid two-phase system for anaerobic digestion of food waste

2002 ◽  
Vol 45 (12) ◽  
pp. 159-165 ◽  
Author(s):  
J.Y. Wang ◽  
H.L. Xu ◽  
J.H. Tay
Keyword(s):  
Anaerobic Digestion ◽  
Food Waste ◽  
Batch Reactor ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Phase System ◽  
Bioreactor Landfills ◽  
Two Phase ◽  
Methanogenic Phase

A hybrid two-phase system, consisting of a solid waste reactor as the acidification reactor and a wastewater reactor, i.e. an upflow anaerobic sludge blanket (UASB) reactor, as the methanogenic reactor, for anaerobic digestion of food waste was investigated. After the pre-acidification stage, COD and total VFA removals in the methanogenic phase were in the ranges of 74-93% and 77-100%, respectively, while leachate COD and total VFA concentrations in the acidification phase decreased by 95% and 97-99%, respectively. Some 99% of the total CH4 generated was from the methanogenic phase with the CH4 content of 68-70%. About 77-79% of TOC, 57-60% of volatile solids and 79-80% of total COD were removed. The results of this laboratory-scale study show that the hybrid two-phase anaerobic batch reactor system is suitable for effective conversion of food waste into CH4 and CO2. The hybrid two-phase system can be further developed into an effective and efficient way to enhance waste stabilization in operating bioreactor landfills.

scholarly journals Influence of Pre-Hydrolysis on Sewage Treatment in an Up-Flow Anaerobic Sludge BLANKET (UASB) Reactor: A Review

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 372 ◽  
Author(s):  
Rajinikanth Rajagopal ◽  
Mahbuboor Choudhury ◽  
Nawrin Anwar ◽  
Bernard Goyette ◽  
Md. Rahaman
Keyword(s):  
Suspended Solids ◽  
Biogas Production ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
High Rate ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Two Phase ◽  
Anaerobic Sludge Blanket

The up-flow anaerobic sludge blanket (UASB) process has emerged as a promising high-rate anaerobic digestion technology for the treatment of low- to high-strength soluble and complex wastewaters. Sewage, a complex wastewater, contains 30–70% particulate chemical oxygen demand (CODP). These particulate organics degrade at a slower rate than the soluble organics found in sewage. Accumulation of non-degraded suspended solids can lead to a reduction of active biomass in the reactor and hence a deterioration in its performance in terms of acid accumulation and poor biogas production. Hydrolysis of the CODP in sewage prior to UASB reactor will ensure an increased organic loading rate and better UASB performance. While single-stage UASB reactors have been studied extensively, the two-phase full-scale treatment approach (i.e., a hydrolysis unit followed by an UASB reactor) has still not yet been commercialized worldwide. The concept of treating sewage containing particulate organics via a two-phase approach involves first hydrolyzing and acidifying the volatile suspended solids without losing carbon (as methane) in the first reactor and then treating the soluble sewage in the UASB reactor. This work reviews the available literature to outline critical findings related to the treatment of sewage with and without hydrolysis before the UASB reactor.

Anaerobic Digestion of Floral Waste and Methane Enrichment: A Sustainable Approach for Waste to Energy Conversion

2020 ◽  
Vol 46 (3) ◽  
pp. 299-303
Author(s):  
Kulkarni Milind B. ◽  
P.M. Ghanegaonkar
Keyword(s):  
Anaerobic Digestion ◽  
Sodium Carbonate ◽  
Food Waste ◽  
Large Scale ◽  
Solid Waste Management ◽  
Biogas Production ◽  
Methane Content ◽  
Waste To Energy ◽  
Chemical Pretreatment ◽  
Energy Demands

Disposal of floral waste into water or landfill because of religious beliefs causes water and soil pollution. The purpose of present experimental work is to find an energy proficient solution for the disposal of floral waste. The method used in the present work includes anaerobic digestion of floral waste for biogas generation. The proposed method aims to follow waste-to-energy approach, for meeting the local energy demands. The techniques for getting enhanced biogas production from floral waste include novel alkaline chemical pretreatment of floral waste, and co-digestion of floral waste along with food waste. Alkaline chemical pretreatment of floral waste using sodium carbonate showed improved biogas production up to 106%, as compared to the traditional sodium hydroxide chemical pretreatment. Also, a reduction in the cost of chemical pretreatment up to 90% was possible. Co-digestion of floral waste along with food waste was also found effective for getting enhanced biogas output. A feedstock mixture of 70% of floral waste and 30% food waste could produce 32.6% more biogas than the singular feedstock in the form of floral waste. Alkaline pretreatment of floral waste using sodium carbonate and co-digestion with food waste seem to be the novelty of the work. Application of chemical absorption technique for biogas quality improvement could enrich the methane content of biogas up to 96%. Large-scale application of the proposed techniques of solid waste management can meet the energy demands at potential locations. The biogas with enriched methane content can suitable for widespread applications, such as vehicular applications and electricity generation for the benefit of the end users.

Enhancement of food waste digestion in the hybrid anaerobic solid-liquid system

2008 ◽  
Vol 57 (9) ◽  
pp. 1369-1373 ◽  
Author(s):  
X. Y. Liu ◽  
H. B. Ding ◽  
S. Sreeramachandran ◽  
O. Stabnikova ◽  
J. Y. Wang
Keyword(s):  
Anaerobic Digestion ◽  
Food Waste ◽  
Waste Treatment ◽  
Liquid System ◽  
Net Energy ◽  
Two Phase ◽  
Treatment Processes ◽  
Pre Treatment ◽  
Solid Liquid ◽  
Net Energy Gain

The hybrid anaerobic solid-liquid (HASL) system is a modified two-phase anaerobic digester for food waste treatment. To enhance the performance of anaerobic digestion in the HASL system, thermal pre-treatment (heating at 150°C for 1 h) and freezing/thawing (freezing for 24 h at−20°C and then thawing for 12 h at 25°C) were proposed for food waste pre-treatment before the anaerobic digestion. Both processes were able to alter the characteristics and structure of food waste favoring substance solubilization, and hence production of methane. However, there was no net energy gain when the energy required by the pre-treatment processes was taken into account.

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