Role of primary sedimentation on plant-wide energy recovery and carbon footprint

2013 ◽  
Vol 68 (4) ◽  
pp. 870-878 ◽  
Author(s):  
Riccardo Gori ◽  
Francesca Giaccherini ◽  
Lu-Man Jiang ◽  
Reza Sobhani ◽  
Diego Rosso
Keyword(s):  
Energy Demand ◽  
Energy Recovery ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Biological Nutrient Removal ◽  
Net Benefit ◽  
Climatic Regions ◽  
Co2 Equivalent ◽  
Wide Energy ◽  
Process Energy

The goal of this paper is to show the effect of primary sedimentation on the chemical oxygen demand (COD) and solids fractionation and consequently on the carbonaceous and energy footprints of wastewater treatment processes. Using a simple rational procedure for COD and solids fraction quantification, we quantify the effects of varying fractions on CO2 and CO2-equivalent mass flows, process energy demand and energy recovery. Then we analysed two treatment plants with similar biological nutrient removal processes in two different climatic regions and quantified the net benefit of gravity separation before biological treatment. In the cases analysed, primary settling increases the solid fraction of COD that is processed in anaerobic digestion, with an associated increase in biogas production and energy recovery, and a reduction in overall emissions of CO2 and CO2-equivalent from power importation.

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 Techno-Cost-Benefit Analysis of Biogas Production from Industrial Cassava Starch Wastewater in Thailand for Optimal Utilization with Energy Storage

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 416
Author(s):  
Chatree Wattanasilp ◽  
Roongrojana Songprakorp ◽  
Annop Nopharatana ◽  
Charoenchai Khompatraporn
Keyword(s):  
Energy Storage ◽  
Energy Demand ◽  
Cost Benefit Analysis ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Value Added ◽  
Operation Time ◽  
Cassava Starch ◽  
Utilization Pathway ◽  
Availability Assessment

This paper applied the optimization model of the biogas utilization pathway with the biogas utilization availability assessment to examine the effect of biogas system parameters on biogas utilization. The model analyzes the biogas utilization pathway availability and maximum profit to value added and productivity in biogas from industry wastewater in Thailand. The results showed that profit and availability of biogas utilization reduce biogas loss to flare, that it entails several conversion processes. The scenario for the biogas utilization pathway and storage with biogas production technology improves. Evaluated are operation time, waste and energy demand to the cassava starch usage during the production for 50–1000 tons per day. Five mature biogas production technologies were benchmarked evaluated based on the chemical oxygen demand removal efficiency and biogas yields. Subsequently, low-, medium-, and high-pressure storages and a battery storage were considered and discussed in this paper as suitable energy storage for each desired biogas plant operation. Five biogas utilization pathways, including converting biogas into thermal energy, generating electricity, and upgrading biogas to compressed biogas, were then compared. Those improved options in the scenario select suitable biogas technologies, storage, and application for value-added, reduce the environmental problems and renewable energy production from wastewater.

scholarly journals Processing High-Solid and High-Ammonia Rich Manures in a Two-Stage (Liquid-Solid) Low-Temperature Anaerobic Digestion Process: Start-Up and Operating Strategies

2020 ◽  
Vol 7 (3) ◽  
pp. 80 ◽  
Author(s):  
Prativa Mahato ◽  
Bernard Goyette ◽  
Md. Saifur Rahaman ◽  
Rajinikanth Rajagopal
Keyword(s):  
Anaerobic Digestion ◽  
Energy Demand ◽  
Biogas Production ◽  
Oxygen Demand ◽  
High Energy ◽  
Poultry Production ◽  
Livestock Farming ◽  
Two Stage ◽  
Batch Mode ◽  
Digestion Process

Globally, livestock and poultry production leads to total emissions of 7.1 Gigatonnes of CO2-equiv per year, representing 14.5% of all anthropogenic greenhouse gas emissions. Anaerobic digestion (AD) is one of the sustainable approaches to generate methane (CH4) from manure, but the risk of ammonia inhibition in high-solids AD can limit the process. Our objective was to develop a two-stage (liquid–solid) AD biotechnology, treating chicken (CM) + dairy cow (DM) manure mixtures at 20 °C using adapted liquid inoculum that could make livestock farming more sustainable. The effect of organic loading rates (OLR), cycle length, and the mode of operation (particularly liquid inoculum recirculation-percolation mode) was evaluated in a two-stage closed-loop system. After the inoculum adaptation phase, aforementioned two-stage batch-mode AD operation was conducted for the co-digestion of CM + DM (Total Solids (TS): 48–51% and Total Kjeldahl Nitrogen (TKN): 13.5 g/L) at an OLR of 3.7–4.7 gVS/L.d. Two cycles of different cycle lengths (112-d and 78-d for cycles 1 and 2, respectively) were operated with a CM:DM mix ratio of 1:1 (w/w) based on a fresh weight basis. Specific methane yield (SMY) of 0.35 ± 0.11 L CH4g/VSfed was obtained with a CH4 concentration of above 60% for both the cycles and Soluble Chemical Oxygen Demand (CODs) and volatile solid (VS) reductions up to 85% and 60%, respectively. For a comparison purpose, a similar batch-mode operation was conducted for mono-digestion of CM (TS: 65–73% and TKN: 21–23 g/L), which resulted in a SMY of 0.52 ± 0.13 L CH4g/VSfed. In terms of efficiency towards methane-rich biogas production and ammonia inhibitions, CM + DM co-digestion showed comparatively better quality methane and generated lower free ammonia than CM mono-digestion. Further study is underway to optimize the operating parameters for the co-digestion process and to overcome inhibitions and high energy demand, especially for cold countries.

Estimates of methane loss and energy recovery potential in anaerobic reactors treating domestic wastewater

2012 ◽  
Vol 66 (12) ◽  
pp. 2745-2753 ◽  
Author(s):  
L. C. S. Lobato ◽  
C. A. L. Chernicharo ◽  
C. L. Souza
Keyword(s):  
Energy Recovery ◽  
Large Scale ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Energy Potential ◽  
Recovery Potential ◽  
Uasb Reactors

This work aimed at developing a mathematical model that could estimate more precisely the fraction of chemical oxygen demand (COD) recovered as methane in the biogas and which, effectively, represented the potential for energy recovery in upflow anaerobic sludge blanket (UASB) reactors treating domestic wastewater. The model sought to include all routes of conversion and losses in the reactor, including the portion of COD used for the reduction of sulfates and the loss of methane in the residual gas and dissolved in the effluent. Results from the production of biogas in small- and large-scale UASB reactors were used to validate the model. The results showed that the model allowed a more realistic estimate of biogas production and of its energy potential.

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 Modification of municipal wastewater for improved biogas recovery

2020 ◽  
Vol 15 (3) ◽  
pp. 683-696
Author(s):  
Vaileth Hance ◽  
Thomas Kivevele ◽  
Karoli Nicholas Njau
Keyword(s):  
Anaerobic Digestion ◽  
Energy Demand ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Organic Content ◽  
Municipal Wastewater Treatment ◽  
Naoh Solution ◽  
Municipal Wastewater Treatment Plants

Abstract The energy demand, which is expected to increase more worldwide, has sparked the interest of researchers to find sustainable and inexpensive sources of energy. This study aims to integrate an energy recovering step into municipal wastewater treatment plants (MWWTPS) through anaerobic digestion. The anaerobic digestion of municipal wastewater (MWW), and then co-digestion with sugar cane molasses (SCM) to improve its organic content, was conducted at 25 °C and 37 °C. The results showed a substrate mixture containing 6% of SCM and total solids (TS) of 7.52% yielded a higher amount of biogas (9.73 L/L of modified substrate). However, chemical oxygen demand (COD) of the resulting digestate was high (10.1 g/L) and pH was not stable, and hence needed careful adjustment using 2 M of NaOH solution. This study recommends a substrate mixture containing SCM (2%) and TS (4.34%) having biogas production (4.97 L/L of modified substrate) for energy recovery from MWWTPS, since it was found to have more stable pH and low COD residue (1.8 g/L), which will not hold back the MWW treatment process. The annual generation of modified substrate (662,973 m3) is anticipated to generate about 16,241 m3 of methane, which produces up to 1.8 GWh and 8,193 GJ per annum.

scholarly journals Biophotocatalytic Reduction of CO2 in Anaerobic Biogas Produced from Wastewater Treatment Using an Integrated System

Catalysts ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 76
Author(s):  
Emmanuel Kweinor Tetteh ◽  
Sudesh Rathilal
Keyword(s):  
Energy Demand ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Micropore Volume ◽  
Organic Content ◽  
Environmental Conservation ◽  
Integrated System ◽  
Organic Loading Rate ◽  
Co2 Emission Reduction ◽  
Co Precipitation

This study presents the bio-photocatalytic upgrading of biogas utilising carbon dioxide (CO2) as a potential option for beginning fossil fuel depletion and the associated environmental risks in the pursuit of sustainable development. Herein, magnetite photocatalyst (Fe-TiO2) was employed with an integrated anaerobic-photomagnetic system for the decontamination of municipality wastewater for biogas production. The Fe-TiO2 photocatalyst used, manufactured via a co-precipitation technique, had a specific surface area of 62.73 m2/g, micropore volume of 0.017 cm3/g and pore size of 1.337 nm. The results showed that using the ultraviolet-visible (UV-Vis) photomagnetic system as a post-treatment to the anaerobic digestion (AD) process was very effective with over 85% reduction in colour, chemical oxygen demand (COD) and turbidity. With an organic loading rate (OLR) of 0.394 kg COD/L·d and hydraulic retention time (HTR) of 21 days, a 92% degradation of the organic content (1.64 kgCOD/L) was attained. This maximised the bioenergy production to 5.52 kWh/m3 with over 10% excess energy to offset the energy demand of the UV-Vis lamp. Assuming 33% of the bioenergy produced was used as electricity to power the UV-Vis lamp, the CO2 emission reduction was 1.74 kg CO2 e/m3, with good potential for environmental conservation.

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