Modelling anaerobic digestion of concentrated black water and faecal matter in accumulation system

2011 ◽  
Vol 63 (9) ◽  
pp. 2039-2045
Author(s):  
Tarek Elmitwalli ◽  
Grietje Zeeman ◽  
Ralf Otterpohl
Keyword(s):  
Waste Water ◽  
Anaerobic Digestion ◽  
Oxygen Demand ◽  
Water Sources ◽  
Experimental Conditions ◽  
Black Water ◽  
Faecal Matter ◽  
Volatile Fatty Acid Concentration ◽  
Seed Sludge ◽  
Urine Separation

A dynamic mathematical model based on anaerobic digestion model no. 1 (ADM1) was developed for accumulation (AC) system treating concentrated black water and faecal matter at different temperatures. The AC system was investigated for the treatment of waste(water) produced from the following systems: vacuum toilet for black water (VBW), vacuum toilet for faeces with urine separation (VF), dry toilet (DT), dry toilets for faeces with urine separation (DF), separated faecal matter from conventional black water by filter bag (FB). For evaluation of the AC system treating the proposed waste(water) sources at 20 and 35°C, two options were studied: (1) The filling period of the AC system was constant for all waste(water) sources (either 1, 3 or 6 months) and for each period, the seed sludge volume was varied; (2) The volume of the AC system was constant for all proposed waste(water) sources. The results showed that the filling period of the AC system was the main parameter affecting the system performance, followed by operational temperature, while the increase of the seed sludge volume slightly enhanced the performance of the system. The model results indicated that the filling period of the AC system should be higher than 150 days for obtaining a stable performance. It was found that the hydrolysis of biodegradable particulate chemical oxygen demand (COD) is the rate limiting step, as volatile fatty acid concentration is very low in all experimental conditions (<200 mgCOD/L at 20 °C and <100 mgCOD/L at 35 °C). Based on the results of the two options, it was found that the concentrated waste(water) sources have better performance than the diluted waste(water) sources, like VBW waste(water). Furthermore, smaller volume will be required for the AC system.

Monitoring of greenhouse gas emissions from farm-scale anaerobic piggery waste-water digesters

2018 ◽  
Vol 156 (6) ◽  
pp. 739-747 ◽  
Author(s):  
Jung-Jeng Su ◽  
Yen-Jung Chen
Keyword(s):  
Waste Water ◽  
Anaerobic Digestion ◽  
Greenhouse Gas ◽  
Waste Water Treatment ◽  
Ghg Emissions ◽  
Oxygen Demand ◽  
Pig Manure ◽  
Intergovernmental Panel ◽  
Pig Farms ◽  
Farm Scale

AbstractPig manure management systems in Taiwan differ from the model representing the Asian region developed by the Intergovernmental Panel on Climate Change (IPCC). The current study was undertaken to update greenhouse gas (GHG) emission factors of anaerobically treated piggery waste water by operating the conventional three-step piggery waste-water treatment system from selected pig farms located in northern, central and southern Taiwan. Biogas mass flow meters were installed to the outlet of anaerobic basins prior to the biogas pressure stabilizers for direct and reliable biogas measurement. The analytic results showed that average GHG emissions were 0.088, 0.128 and 0.066 m3/head/day in the northern, central and southern pig farms, respectively. Thus, the average emission levels of methane and nitrous oxide were 14.38 and 0.055 kg/head/year, respectively, from anaerobic digestion of piggery waste water for the three pig farms. The average removal efficiency of chemical oxygen demand, biochemical oxygen demand and suspended solids by anaerobic digestion process from the three pig farms was about 77, 93 and 70%, respectively.

Characterization and anaerobic treatability study of pre-hydrolysis liquor (PHL) from dissolving pulp mill

2013 ◽  
Vol 48 (2) ◽  
pp. 145-154 ◽  
Author(s):  
Dibyendu Debnath ◽  
Mayur M. Kale ◽  
Kripa S. Singh
Keyword(s):  
Acetic Acid ◽  
Anaerobic Digestion ◽  
Anaerobic Degradation ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Pulp Mill ◽  
Threshold Value ◽  
Dissolving Pulp ◽  
Lignin Concentration ◽  
Seed Sludge

Anaerobic degradation showed potential as the disposal solution for pre-hydrolysis liquor (PHL) from the dissolving pulp industries. This PHL contained pentose and hexose carbohydrates as monomeric (14.5 g/L) and oligomeric (39.7 g/L) forms along with acetic acid (10.38 g/L), furfural (1.14 g/L) and lignin (11.08 g/L). The average chemical oxygen demand (COD) value of the PHL was around 100 g/L with a biochemical oxygen demand (BOD5) value of 55 g/L. Respirometric studies at 35 °C showed a decrease in methane production with increasing concentration of PHL in the feed. Presence of slowly biodegradable substrates (furfural and lignin) in the feed was suspected to cause such behavior. Therefore, PHL was introduced to a master culture reactor to acclimatize the seed sludge to PHL as substrate. The seed microbes were able to adapt to furfural, but not to the entire lignin present in PHL feed. Lignin concentration going over a threshold value (approximately 7 g/L) was suspected to cause reactor failure. This anaerobic treatability study reflects on the potential of applying anaerobic digestion for PHL waste stream disposal and biogas production.

Sludge accumulation and conversion to methane in a septic tank treating domestic wastewater or black water

2013 ◽  
Vol 68 (4) ◽  
pp. 956-964 ◽  
Author(s):  
Tarek Elmitwalli
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Septic Tank ◽  
Black Water ◽  
Operational Temperature ◽  
Filling Time ◽  
Pre Treatment ◽  
Sludge Accumulation

Although the septic tank is the most applied on-site system for wastewater pre-treatment, limited research has been performed to determine sludge accumulation and biogas production in the tank. Therefore a dynamic mathematical model based on the Anaerobic Digestion Model No. 1 (ADM1) was developed for anaerobic digestion of the accumulated sludge in a septic tank treating domestic wastewater or black water. The results showed that influent chemical oxygen demand (COD) concentration and hydraulic retention time (HRT) of the tank mainly control the filling time with sludge, while operational temperature governs characteristics of the accumulated sludge and conversion to methane. For obtaining stable sludge and high conversion, the tank needs to be operated for a period more than a year without sludge wasting. Maximum conversion to methane in the tank is about 50 and 60% for domestic wastewater and black water, respectively. The required period for sludge wasting depends on the influent COD concentration and the HRT, while characteristics of the wasted sludge are affected by operational temperature followed by the influent COD concentration and the HRT. Sludge production from the tank ranges between 0.19 to 0.22 and 0.13 to 0.15 L/(person.d), for the domestic wastewater and black water, respectively.

Anaerobic digestion technologies for closing the domestic water, carbon and nutrient cycles

2000 ◽  
Vol 41 (3) ◽  
pp. 203-211 ◽  
Author(s):  
F. Hammes ◽  
Y. Kalogo ◽  
W. Verstraete
Keyword(s):  
Anaerobic Digestion ◽  
Solid Waste ◽  
Life Support ◽  
Oxygen Demand ◽  
Post Treatment ◽  
Microbial Pathogens ◽  
Domestic Water ◽  
Black Water ◽  
Semi Solid ◽  
Treatment Alternatives

Sustainable wastewater treatment requires that household wastewater is collected and treated separately from industrial wastewater and rainwater run-offs. This separate treatment is, however, still inadequate, as more than 70% of the nutrients and much of the chemical oxygen demand (COD) and potential pathogens of a domestic sewage system are confined to the few litres of black water (faeces, urine and toilet water). Whilst grey water can easily be filter treated and re-used for secondary household purposes, black water requires more intensive treatment due to its high COD and microbial (pathogens) content. Recently developed vacuum/dry toilets produce a nutrient rich semi-solid waste stream, which, with proper treatment, offers the possibility of nutrient, carbon, water and energy recovery. This study investigates the terrestrial applicability of Life Support System (LSS) concepts as a framework for future domestic waste management. The possibilities of treating black water together with other types of human-generated solid waste (biowastes/mixed wastes) in an anaerobic reactor system at thermophilic conditions, as well as some post treatment alternatives for product recovery and re-use, are considered. Energy can partially be recovered in the form of biogas produced during anaerobic digestion. The system is investigated in the form of theoretical mass balances, together with an assessment of the current feasibility of this technology and other post-treatment alternatives.

scholarly journals Effect of Assisted Ultrasonication and Ozone Pretreatments on Sludge Characteristics and Yield of Biogas Production

Processes ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 743 ◽  
Author(s):  
Tuan Minh Le ◽  
Phong Thanh Vo ◽  
Tuan Anh Do ◽  
Lien Thi Tran ◽  
Hoa Thi Truong ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Chemical Oxygen Demand ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Physicochemical Characteristics ◽  
Control Case ◽  
Solid Retention Time ◽  
Experimental Conditions ◽  
Anaerobic Biodegradability ◽  
And Control

The effects of ultrasonic and ozonation pretreatments on organic solubilization, anaerobic biodegradability, and biogas production were elucidated in this study. Two pretreatment methods for batch anaerobic digestion for biogas recovery with the same material and experimental conditions were the focus for comparison. Anaerobic digestion experiments were conducted at ambient temperature with the solid retention time set to 25 days. The obtained results indicated that the soluble chemical oxygen demand increased from 0.344 without pretreatment to 1.023 and 1.228 g/L with ultrasound and ozone pretreatments, respectively, whereas the yields of biogas production in the 25 days increased by 32.3 and 52.9% via ultrasonic irradiation and ozonation relative to the control case, respectively. The biodegradability of the organic compounds of the samples for the cases of ultrasound, ozone pretreatments, and control achieved 55.9, 64.31, and 39.18%, respectively, in terms of chemical oxygen demand (COD) removal efficiencies. The physicochemical characteristics of sludge flocs were investigated via scanning with particle sizes, which were obviously affected by pretreatments of sonication and ozonation, resulting in finer particles than in the control case.

Mesophilic and thermophilic anaerobic digestion of sulphate-containing wastewaters

2002 ◽  
Vol 45 (10) ◽  
pp. 231-235 ◽  
Author(s):  
S. Colleran ◽  
S. Pender
Keyword(s):  
Anaerobic Digestion ◽  
Oxygen Demand ◽  
Methanobacterium Thermoautotrophicum ◽  
Operational Performance ◽  
Thermophilic Anaerobic Digestion ◽  
Seed Sludge ◽  
Thermophilic Conditions ◽  
Reducing Bacteria ◽  
Hybrid Reactors

The effect of sulphate at an influent chemical oxygen demand (COD):sulphate ratio of 4 on the operational performance of anaerobic hybrid reactors treating molasses wastewater was investigated under mesophilic and thermophilic conditions in a long-term laboratory-scale study over a 1,081 day period. The presence of sulphate reduced the COD removal efficiency under both mesophilic and thermophilic conditions. At 55°C, effluent acetate levels were consistently greater than 4000 mg L−1, indicating that thermophilic acetate-utilising methane-producing bacteria (MPB) or sulphate-reducing bacteria (SRB) had not developed in the reactor under the conditions applied. At 37°C, acetate was exclusively utilised by acetoclastic methanogens, whereas H2-utilising SRB predominated over H2-utilising MPB in the competition for hydrogen. By contrast, hydrogenotrophic MPB were shown to outcompete H2-utilising SRB during long-term thermophilic operation. 16SrDNA analysis of the seed sludge and reactor biomass on conclusion of the 37°C and 55°C trials illustrated that the dominant methanogen present on conclusion of the thermophilic trial in the absence of influent sulphate was related to Methanocorpusculum parvuum, and was capable of growth on both acetate and hydrogen. By contrast, an organism closely related to Methanobacterium thermoautotrophicum was the dominant methanogen present in the sulphate-fed reactor on completion of the thermophilic trial.

scholarly journals Indirect Monitoring of Anaerobic Digestion for Cheese Whey Treatment

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 539
Author(s):  
Hilario Flores-Mejia ◽  
Antonio Lara-Musule ◽  
Eliseo Hernández-Martínez ◽  
Ricardo Aguilar-López ◽  
Hector Puebla
Keyword(s):  
Experimental Data ◽  
Anaerobic Digestion ◽  
Fractal Analysis ◽  
Cheese Whey ◽  
Sliding Mode ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Data Driven ◽  
Process Variables ◽  
Experimental Conditions

Efficient monitoring is an open problem in the operation of anaerobic digestion processes, due to the lack of accurate, low-cost, and proper sensors for the on-line monitoring of key process variables. This paper presents two approaches for the indirect monitoring of the anaerobic digestion of cheese whey wastewater. First, the observability property is addressed using conventional and nonconventional techniques, including an observability index. Then, two model-based observer techniques, an extended Luenberger observer, a sliding mode observer, and a data-driven technique based on fractal analysis are formulated and discussed. The performance and capabilities of the proposed methodologies are illustrated on a validated model with experimental data of the anaerobic digestion of cheese whey. Experimental pH measurements are used for the data-driven approach based on fractal analysis. The experimental data sets correspond to experimental conditions (pH > 7.5 and temperature (T) = 40 °C) favoring volatile fatty acid (VFA) production (30 g/L) with simultaneously acceptable biogas production (3420 mL). Results also show that the proposed observers were able to predict satisfactory key process variables. On the other hand, the fractal analysis provides reliable qualitative trends of VFA production and chemical oxygen demand (COD) consumption.

scholarly journals Study on Chromaticity Removal from Mineral Processing Wastewater with Salicylic Hydroxamic Acid by Granular Activated Carbon Catalyzed Ozonation

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 359
Author(s):  
Liping Zhang ◽  
Shengnian Wu ◽  
Nan Zhang ◽  
Ruihan Yao ◽  
Eryong Wu
Keyword(s):  
Activated Carbon ◽  
Reaction Time ◽  
Hydroxamic Acid ◽  
Ph Value ◽  
Oxygen Demand ◽  
Granular Activated Carbon ◽  
Mineral Processing ◽  
Ultraviolet Absorption Spectrum ◽  
Experimental Conditions ◽  
Removal Ratio

Salicylic hydroxamic acid is a novel flotation reagent used in mineral processing. However, it impacts the flotation wastewater leaving behind high chromaticity which limits its reuse and affects discharge for mining enterprises. This study researched ozonation catalyzed by the granular activated carbon (GAC) method to treat the chromaticity of the simulated mineral processing wastewater with salicylic hydroxamic acid. The effects of pH value, ozone (O3) concentration, GAC dosage, and reaction time on chromaticity and chemical oxygen demand (CODCr) removal were discussed. The results of individual ozonation experiments showed that the chromaticity removal ratio reached 79% and the effluent chromaticity exceeded the requirement of reuse and discharge when the optimal experimental conditions were pH value 3, ozone concentration 6 mg/L, and reaction time 40 min. The orthogonal experimental results of catalytic ozonation with GAC on chromaticity removal explained that the chromaticity removal ratio could reach 96.36% and the chromaticity of effluent was only 20 when the optimal level of experimental parameters was pH value 2.87, O3 concentration 6 mg/L, GAC dosage 0.06 g/L, reaction time 60 min respectively. The degradation pathway of salicylic hydroxamic acid by ozonation was also considered based on an analysis with ultraviolet absorption spectrum and high-performance liquid chromatography (HPLC).

Study on Water Quality Improvement of Streams in Baoan District, Shenzhen City, China

2011 ◽  
Vol 347-353 ◽  
pp. 1902-1905
Author(s):  
Hua Li You
Keyword(s):  
Waste Water ◽  
Mathematical Model ◽  
Water Quality ◽  
Fresh Water ◽  
Water Discharge ◽  
Water Environment ◽  
Oxygen Demand ◽  
Polluted Water ◽  
Integrated Analysis ◽  
Shenzhen City

Water is the basis of natural resources and strategic economic resources.Deteriorated water environment of streams in Shenzhen city could have a great impact on ecological safety, people's health,and economic development.Based on the data of field observation and Remote sensing (RS) image,integrated analysis of the water degradation causes,and the changes of biochemical oxygen demand in five days(BOD5）concentration by mathematical model were carried out,which is on basis of percentage of waste water disposal,fresh water transformation,and harbor excavation, respectively.The results show that degradation causes of water quality were resulted from waste water discharge, harbor construction,and ecological environment damage, which could lead to slowly water exchange. Accordingly,the pollution can be easily to store in the bay,which result in water quality changes.The most important improved countermeasure is the control of waste water, which could be had a great effectiveness to decrease pollution.In addition, fresh water must be supplied after polluted water was cut off,which can be better improvement for water quality.This would be extreme improvement for hydrological dynamics due to 15m harbor excavation,which can significantly reduce BOD5 concentration.The innovation points of this paper is to mathematical model,which is based on the basis of qualitative analysis.

scholarly journals Decentral Energy Generation Potential of Anaerobic Digestion of Black Water and Kitchen Refuse for Eco-District Planning

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2948
Author(s):  
Soufia Mohammadi ◽  
Pilar Monsalvete Álvarez de Uribarri ◽  
Ursula Eicker
Keyword(s):  
Experimental Data ◽  
Anaerobic Digestion ◽  
Energy Demand ◽  
Alternative Energy ◽  
Organic Substrate ◽  
Mass Balances ◽  
Waste Streams ◽  
Black Water ◽  
Alternative Energy Source ◽  
Simulation Based

Biogas technology is an important alternative energy source worldwide. Blackwater and kitchen refuse represent ideal waste streams for bioenergy recovery through anaerobic co-digestion. Modeling of the biokinetics of anaerobic digestion on several aspects, such as microbial activity, substrate degradation, and methane production, from co-digestion of black water (BW) and kitchen refuse (KR) was the objective of this research. A mathematical model was developed towards a simulation based on mass balances on biomass, the organic substrate, and biogas. The model was implemented in INSEL and experimental data from the literature were used for model validation. The study shows that the simulation results fit well with the experimental data. The energy consumption and generation potential of anaerobic co-digestion of BW and KR were calculated to investigate if the produced biogas could supply the digester’s energy demand. This study can be used to pre-design anaerobic digestion systems in eco-districts.

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