Enhanced anaerobic digestion as a sanitation and energy recovery technology

2013 ◽  
Vol 3 (4) ◽  
pp. 572-581 ◽  
Author(s):  
T. Garoma ◽  
C. Williams
Keyword(s):  
Anaerobic Digestion ◽  
Energy Recovery ◽  
Waste Treatment ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Total Coliform ◽  
Operational Parameters ◽  
Nitrogen And Phosphorus ◽  
Treatment Technology ◽  
Volatile Solids

The potential for using an enhanced anaerobic digestion (AD) process as a sanitation and energy recovery technology for communities that lack access to basic sanitation was evaluated. For the enhanced AD system to generate a reliable supply of biogas, so that it can be adopted and self-sustained by the community, the use of algal biomass as a supplementary feedstock was evaluated. In addition, the effects of operational parameters on waste mineralization and biogas production were investigated. The results show that the system has the potential to be developed into an effective waste treatment technology, and it has produced high biogas yields and digested waste low in fecal bacteria and high in nutrients. Reductions of 42 to 51% in volatile solids and 29 to 45% in chemical oxygen demand were achieved at 35 °C. On average, total coliform and fecal coliform concentrations of 7.6 × 105 and 1.4 × 104 CFU per gram of total solids, respectively, were measured in the digested waste. The total nitrogen and phosphorus content of the residual was determined to be in the range of 9–17% as N and 3–7% as P (7–16% as P2O5). The biogas yields varied in the range of 0.47–0.57 mL per mg of volatile solids digested.

scholarly journals EFFECTIVE MICROORGANISMS (EM) AS BIOFEEDERS FOR ANAEROBIC DIGESTION

2017 ◽  
Vol 25 (6) ◽  
pp. 491-499
Author(s):  
Cecília De Fátima Souza Ferreira ◽  
Richard Stephen Gates ◽  
Maurílio Duarte Batista ◽  
Ilda De Fatima Ferreira TINOCO
Keyword(s):  
Anaerobic Digestion ◽  
Waste Treatment ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Effective Microorganisms ◽  
Anaerobic Digesters ◽  
Volatile Solids ◽  
Low Concentrations ◽  
Total Capacity ◽  
Micro Organisms

Soil micro-organisms called Effective Microorganisms (EM) were first cultivated and used in the 1970s. Researches about these cultures have since then demonstrated their effectiveness in improving soil characteristics and as an alternative for accelerating organic matter decomposition in waste treatment systems. The objective of this study was to test whether the addition of EM to substrates incubated in anaerobic digesters would increase the efficiency of waste treatment and biogas production. EM cultures were obtained from bacterial colonies captured within the A-horizon of a Brazilian forest soil. They were left to grow during 15 days on cooked rice contact with the soil; afterwards, the established colonies were separated according to their colors, discarding all shades of black, gray and white, according to recommendations from related literature. Remaining colonies were further grown in sugarcane broth medium for 18 days, being this the final EM culture. Twelve bench digesters were used, each with a total capacity for three liters. The experiment was composed by four treatments consisting of different concentrations of EM inoculum [15% (T1), 10% (T2), 1% (T3) and 0% (T4)] applied to dairy cattle manure, with three replications per treatment. Anaerobic digestion was carried out under controlled temperature (35oC) over 99 days. Data collected included concentrations of total, fixed and volatile solids (TS, FS and VS), pH and Chemical Oxygen Demand (COD). The pH of the EM inoculum was 3.34 and COD was 24.25 mg L-1. The best reduction efficiencies for COD and TS removal were 79.44% and 42.50%, respectively, in T4. Among the treatments with EM addition, 1% (T3) resulted in better COD reduction. The maximum accumulated biogas production was 20.60 L biogas L substrate-1, also for T3. In conclusion, EM as an inoculum in low concentrations may be advantageous to anaerobic digestion.

Sludge electrooxidation as pre-treatment for anaerobic digestion

2016 ◽  
Vol 75 (4) ◽  
pp. 775-781 ◽  
Author(s):  
J. A. Barrios ◽  
U. Duran ◽  
A. Cano ◽  
M. Cisneros-Ortiz ◽  
S. Hernández
Keyword(s):  
Anaerobic Digestion ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Wastewater Sludge ◽  
Boron Doped Diamond ◽  
Boron Doped ◽  
Treatment Conditions ◽  
Volatile Solids ◽  
Pre Treatment

Anaerobic digestion of wastewater sludge is the preferred method for sludge treatment as it produces energy in the form of biogas as well as a stabilised product that may be land applied. Different pre-treatments have been proposed to solubilise organic matter and increase biogas production. Sludge electrooxidation with boron-doped diamond electrodes was used as pre-treatment for waste activated sludge (WAS) and its effect on physicochemical properties and biomethane potential (BMP) was evaluated. WAS with 2 and 3% total solids (TS) achieved 2.1 and 2.8% solubilisation, respectively, with higher solids requiring more energy. After pre-treatment, biodegradable chemical oxygen demand values were close to the maximum theoretical BMP, which makes sludge suitable for energy production. Anaerobic digestion reduced volatile solids (VS) by more than 30% in pre-treated sludge with a food to microorganism ratio of 0.15 g VSfed g−1 VSbiomass. Volatile fatty acids were lower than those for sludge without pre-treatment. Best pre-treatment conditions were 3% TS and 28.6 mA cm−2.

scholarly journals Material Characterization and Substrate Suitability Assessment of Chicken Manure for Dry Batch Anaerobic Digestion Processes

2020 ◽  
Vol 7 (3) ◽  
pp. 106
Author(s):  
Harald Wedwitschka ◽  
Daniela Gallegos Ibanez ◽  
Franziska Schäfer ◽  
Earl Jenson ◽  
Michael Nelles
Keyword(s):  
Anaerobic Digestion ◽  
Waste Treatment ◽  
Chicken Manure ◽  
Volatile Components ◽  
Treatment Technology ◽  
Fresh Matter ◽  
Suitability Assessment ◽  
Volatile Solids ◽  
Methane Potential ◽  
Percolation Processes

Chicken manure is an agricultural residue material with a high biomass potential. The energetical utilization of this feedstock via anaerobic digestion is an interesting waste treatment option. One waste treatment technology most appropriate for the treatment of stackable (non-free-flowing) dry organic waste materials is the dry batch anaerobic digestion process. The aim of this study was to evaluate the substrate suitability of chicken manure from various sources as feedstock for percolation processes. Chicken manure samples from different housing forms were investigated for their chemical and physical material properties, such as feedstock composition, permeability under compaction and material compressibility. The permeability under compaction of chicken manure ranged from impermeable to sufficiently permeable depending on the type of chicken housing, manure age and bedding material used. Porous materials, such as straw and woodchips, were successfully tested as substrate additives with the ability to enhance material mixture properties to yield superior permeability and allow sufficient percolation. In dry anaerobic batch digestion trials at lab scale, the biogas generation of chicken manure with and without any structure material addition was investigated. Digestion trials were carried out without solid inoculum addition and secondary methanization of volatile components. The specific methane yield of dry chicken manure was measured and found to be 120 to 145 mL/g volatile solids (VS) and 70 to 75 mL/g fresh matter (FM), which represents approximately 70% of the methane potential based on fresh mass of common energy crops, such as corn silage.

scholarly journals Anaerobic co-digestion of hatchery waste and wastewater to produce energy and biofertilizer - Batch phase

2017 ◽  
Vol 21 (9) ◽  
pp. 651-656 ◽  
Author(s):  
Juliana M. Matter ◽  
Mônica S. S. de M. Costa ◽  
Luiz A. de M. Costa ◽  
Dercio C. Pereira ◽  
Amarílis de Varennes ◽  
...  
Keyword(s):  
Energy Recovery ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Average Concentration ◽  
Swine Wastewater ◽  
Batch Test ◽  
Potential Production ◽  
Carbon Dioxide Gas ◽  
Volatile Solids ◽  
Macro And Micronutrients

ABSTRACT Aiming to evaluate different wastewaters in the anaerobic co-digestion (ACoD) of hatchery wastes, a batch test was conducted in bench horizontal digesters. At the end of the process, the potential production of biogas and methane was calculated as well as the chemical composition (macro- and micronutrients) of the effluent and the concentrations of methane and carbon dioxide gas at 60 days. The monitoring of the process included observations of the reduction of the organic carbon, chemical oxygen demand, and total (TS) and volatile solids (VS), as well as the variation of pH and electrical conductivity (EC). The results showed that the mixing between the hatchery fresh waste and swine wastewater (T4) and among fresh hatchery waste, water from the first anaerobic pond of the hatchery and swine wastewater (T5) represent significant sources of renewable energy and thereby greater potential for biogas production (192.50 and 205.0 L biogas per kg of VS added to T4 and T5, respectively). The average concentration of methane in the biogas varied from 72 to 77% among the treatments. For all treatments, reductions were observed in TS and VS and increases in pH and EC. It was concluded that the energy recovery from hatchery wastes is favoured by the addition of swine wastewater in the ACoD process.

Laboratory-scale membrane up-concentration and co-anaerobic digestion for energy recovery from sewage and kitchen waste

2015 ◽  
Vol 73 (3) ◽  
pp. 597-606 ◽  
Author(s):  
Nguyen Thi Tuyet ◽  
Nguyen Phuoc Dan ◽  
Nguyen Cong Vu ◽  
Nguyen Le Hoang Trung ◽  
Bui Xuan Thanh ◽  
...  
Keyword(s):  
Energy Recovery ◽  
Membrane Filtration ◽  
Waste Treatment ◽  
Biogas Production ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Integrated System ◽  
Total Carbon ◽  
Organic Loading Rate ◽  
Kitchen Waste

This study assessed an alternative concept for co-treatment of sewage and organic kitchen waste in Vietnam. The goal was to apply direct membrane filtration for sewage treatment to generate a permeate that is suitable for discharge. The obtained chemical oxygen demand (COD) concentrations in the permeate of ultrafiltration tests were indeed under the limit value (50 mg/L) of the local municipal discharge standards. The COD of the concentrate was 5.4 times higher than that of the initial feed. These concentrated organics were then co-digested with organic kitchen wastes at an organic loading rate of 2.0 kg VS/m3.d. The volumetric biogas production of the digester was 1.94 ± 0.34 m3/m3.d. The recovered carbon, in terms of methane gas, accounted for 50% of the total carbon input of the integrated system. Consequently, an electrical production of 64 Wh/capita/d can be obtained when applying the proposed technology with the current wastes generated in Ho Chi Minh City. Thus, it is an approach with great potential in terms of energy recovery and waste treatment.

scholarly journals Methodological Approaches to Optimising Anaerobic Digestion of Water Hyacinth for Energy Efficiency in South Africa

2021 ◽  
Vol 13 (12) ◽  
pp. 6746
Author(s):  
Obianuju Patience Ilo ◽  
Mulala Danny Simatele ◽  
S’phumelele Lucky Nkomo ◽  
Ntandoyenkosi Malusi Mkhize ◽  
Nagendra Gopinath Prabhu
Keyword(s):  
South Africa ◽  
Anaerobic Digestion ◽  
Water Hyacinth ◽  
Energy Demand ◽  
Energy Recovery ◽  
Biogas Production ◽  
Meta Analysis ◽  
Operational Parameters ◽  
Invasive Alien Plants ◽  
Methodological Approaches

Anaerobic digestion has been identified as a feasible fragment of a bioeconomy, yet numerous factors hinder the adoption of the technology in South Africa. Apart from its energy recovery, other nonmarket advantages support the technology. Though it may be challenging to have a price tag, they provide clear added worth for such investments. With a growing energy demand and global energy transitions, there is a need to sustainably commercialise the biogas industry in South Africa. Most studies are at laboratory scale and under specific conditions, which invariably create gaps in using their data for commercialising the biogas technology. The key to recognising these gaps depends on knowing the crucial technical phases that have the utmost outcome on the economics of biogas production. This study is a meta-analysis of the optimisation of anaerobic digestion through methodological approaches aimed at enhancing the production of biogas. This review, therefore, argues that regulating the fundamental operational parameters, understanding the microbial community’s interactions, and modelling the anaerobic processes are vital indicators for improving the process stability and methane yield for the commercialisation of the technology. It further argues that South Africa can exploit water hyacinth as a substrate for a self-sufficient biogas production system in a bid to mitigate the invasive alien plants.

scholarly journals Application of electromagnetic field in anaerobic biodigestion in batch reactors

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 4972-4981
Author(s):  
Julios César de Souza Matos ◽  
Ladislav Rozenský ◽  
Zdeněk Vrba ◽  
Justin Michael Hansen ◽  
Miroslav Hájek ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Anaerobic Digestion ◽  
Waste Treatment ◽  
Biogas Production ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Granular Sludge ◽  
Anaerobic Treatment ◽  
Batch Reactors ◽  
Constant Electromagnetic Field

Anaerobic digestion processes with biogas production are widely used for organic waste treatment with an emphasis on energy recovery. Some recent studies have demonstrated the influence of magnetism on microbiological activity. These indicate a possible influence on the efficiency of anaerobic digestion. Thus, technologies that act in anaerobic digestion enhancement can contribute to the improvement of treatment of organic compounds. The present study aimed to verify the influence of a constant electromagnetic field on the anaerobic digestion in anaerobic reactors fed with glucose (2 g/L) at 37 ± 2 °C. In each experiment, reactors were operated with a constant electromagnetic field of 5, 7.5, and 10 mT. The inoculum was granular sludge from an anaerobic treatment plant in a non-selective media culture. Biogas production, chemical oxygen demand (COD), and solids removal were measured during the experiment. Results showed differences in methane production of 21.5% and in COD removal of 15% in the tests with an electromagnetic field of 7.5 mT. These results signs for the viability of the application of a constant magnetic field as a biostimulation agent.

A modified anaerobic digestion process with chemical sludge pre-treatment and its modelling

2014 ◽  
Vol 69 (11) ◽  
pp. 2350-2356 ◽  
Author(s):  
N. M. Hai ◽  
S. Sakamoto ◽  
V. C. Le ◽  
H. S. Kim ◽  
R. Goel ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Biogas Production ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Municipal Wastewater Treatment ◽  
Simulation Accuracy ◽  
Volatile Solids ◽  
Pre Treatment

Activated Sludge Models (ASMs) assume an unbiodegradable organic particulate fraction in the activated sludge, which is derived from the decay of active microorganisms in the sludge and/or introduced from wastewater. In this study, a seasonal change of such activated sludge constituents in a municipal wastewater treatment plant was monitored for 1.5 years. The chemical oxygen demand ratio of the unbiodegradable particulates to the sludge showed a sinusoidal pattern ranging from 40 to 65% along with the change of water temperature in the plant that affected the decay rate. The biogas production in a laboratory-scale anaerobic digestion (AD) process was also affected by the unbiodegradable fraction in the activated sludge fed. Based on the results a chemical pre-treatment using H2O2 was conducted on the digestate to convert the unbiodegradable fraction to a biodegradable one. Once the pre-treated digestate was returned to the digester, the methane conversion increased up to 80% which was about 2.4 times as much as that of the conventional AD process, whilst 96% of volatile solids in the activated sludge was digested. From the experiment, the additional route of the organic conversion processes for the inert fraction at the pre-treatment stage was modelled on the ASM platform with reasonable simulation accuracy.

scholarly journals Analysis of the physicochemical process in the production of biogas from equine manure

2021 ◽  
Vol 2139 (1) ◽  
pp. 012009
Author(s):  
J M Sanchez-Beltrán ◽  
J C Acevedo-Páez ◽  
F Moreno Gamboa
Keyword(s):  
Organic Matter ◽  
Anaerobic Digestion ◽  
Chemical Oxygen Demand ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Physicochemical Process ◽  
Methanogenic Bacteria ◽  
Volatile Solids ◽  
Lower Heating Value ◽  
Ph Level

Abstract The present research aims to evaluate the physicochemical variables involved in the anaerobic digestion process to produce methane from manure on an agricultural farm; the farm has 2 equines that generate 12 Kg of manure per day. A manure sample was collected, and the following physicochemical parameters were determined: total solids, volatile solids, chemical oxygen demand, and pH. A tubular household biodigester was then implemented, consisting mainly of a polyethylene geomembrane that stores the organic matter and in which anaerobic digestion takes place. The performance of the biodigester was determined by the removal of organic matter quantified by volatile solids and chemical oxygen demand in the biodigester influent and digestate, of which removal of 82% of volatile solids and 74% of chemical oxygen demand was achieved. The average biogas production was 0.5 m3/day, and its lower heating value was 26,000 kJ/m3. The pH level of the biodigester was within the range of 6-7, in order to keep the methanogenic bacteria active, in charge of carrying out physicochemical process that guarantees anaerobic digestion and thus, the production of biogas.

scholarly journals Biochemical Methane Potential of Cork Boiling Wastewater at Different Inoculum to Substrate Ratios

2021 ◽  
Vol 11 (7) ◽  
pp. 3064
Author(s):  
Roberta Mota-Panizio ◽  
Manuel Jesús Hermoso-Orzáez ◽  
Luis Carmo-Calado ◽  
Gonçalo Lourinho ◽  
Paulo Sérgio Duque de Brito
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Treatment Plant ◽  
Organic Substrates ◽  
Biochemical Methane Potential ◽  
Volatile Solids ◽  
Working Volume ◽  
Methane Potential ◽  
Bmp Test ◽  
Cork Industry

The present study evaluates the digestion of cork boiling wastewater (CBW) through a biochemical methane potential (BMP) test. BMP assays were carried out with a working volume of 600 mL at a constant mesophilic temperature (35 °C). The experiment bottles contained CBW and inoculum (digested sludge from a wastewater treatment plant (WWTP)), with a ratio of inoculum/substrate (Ino/CBW) of 1:1 and 2:1 on the basis of volatile solids (VSs); the codigestion with food waste (FW) had a ratio of 2/0.7:0.3 (Ino/CBW:FW) and the codigestion with cow manure (CM) had a ratio of 2/0.5:0.5 (Ino/CBW:CM). Biogas and methane production was proportional to the inoculum substrate ratio (ISR) used. BMP tests have proved to be valuable for inferring the adequacy of anaerobic digestion to treat wastewater from the cork industry. The results indicate that the biomethane potential of CBWs for Ino/CBW ratios 1:1 and 2:1 is very low compared to other organic substrates. For the codigestion tests, the test with the Ino/CBW:CM ratio of 2/0.7:0.3 showed better biomethane yields, being in the expected values. This demonstrated that it is possible to perform the anaerobic digestion (AD) of CBW using a cosubstrate to increase biogas production and biomethane and to improve the quality of the final digestate.

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