Effect of Stillage Pretreatment During a Coupled Scoria-Supported Anaerobic Digestion Followed by Aerobic Degradation

The objective of this study was to evaluate the treatment efficiency of a coupled stillage anaerobic digestion, which was performed in scoria-packed continuous reactors and following aerobic degradation. The optimum organic loading rate was determined for the continuous anaerobic digestion of a molasses ethanol distillery stillage with and without wet air feed pretreatment. The pretreatment of the molasses ethanol distillery stillage brought a significantly higher chemical oxygen demand removal in anaerobic digestion with an increased loading rate of 2000 mg/L d when compared with the raw stillage. The results also showed a complete removal of the biological oxygen demand following the coupling of anaerobic digestion with aerobic degradation. During the later stillage aerobic treatment, 68% of the chemical oxygen demand was removed within 8 hours of retention time. Despite the color, the removal of organics in stillage due to integrating wet air pretreatment, continuous anaerobic digestion, and aerobic degradation was successful. The pretreatment and hybrid technique also appears as a promising technique toward the sustainable management of stillage, thereby meeting discharge limit set for the ethanol industry by regulators.

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Evaluation of Organic Loading Rate and Chemical Oxygen Demand Removal: A Coupled Anaerobic-aerobic Treatment Approach for Molasses Distillery Stillage Treatment

10.21203/rs.3.rs-107266/v1 ◽

2020 ◽

Author(s):

Getachew D. Gebreeyessus ◽

Andualem Mekonnen ◽

Yonas Chebude ◽

Asaithambi Perumal ◽

Esayas Alemayehu

Keyword(s):

Chemical Oxygen Demand ◽

Sustainable Management ◽

Loading Rate ◽

Treatment Approach ◽

Oxygen Demand ◽

Complete Removal ◽

Organic Loading Rate ◽

Aerobic Treatment ◽

Organic Loading ◽

Promising Technique

Abstract The objective of the current study is to determine the optimum organic loading rate for a continuous anaerobic digestion (AD) of an ethanol distillery stillage with and without of feed pretreatment. The AD has been performed in scoria packed continuous reactors. The pretreatment of the molasses ethanol distillery stillage brought a significantly better chemical oxygen demand (COD) removal with an increased loading rate to 2000 mg/L-d, when compared with the raw. The results obtained also showed a complete removal of the BOD, which was realized after applying the coupling of AD and aerobic treatments. During aerobic treatment, 68% of the organics were removed within eight hours of retention time. Despite the persistence of color, the removal of organics from integrating the wet air pretreatment, continuous AD and aerobic remediations appear to be promising technique towards the sustainable management of stillage thereby meeting discharge limits.

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Working Parameters Optimization of Hydrolysis-acidogenesis reactor in two stage anaerobic digestion of slaughterhouse Wastewater for Biogas Production

10.21203/rs.2.20690/v1 ◽

2020 ◽

Author(s):

Dejene Tsegaye Bedane ◽

Mohammed Mazharuddin Khan ◽

Seyoum Leta Asfaw

Keyword(s):

Anaerobic Digestion ◽

Working Conditions ◽

Retention Time ◽

Hydraulic Retention Time ◽

Loading Rate ◽

Oxygen Demand ◽

Organic Loading Rate ◽

Organic Loading ◽

Slaughterhouse Wastewater ◽

Working Parameters

Abstract Background : Wastewater from agro-industries such as slaughterhouse is typical organic wastewater with high value of biochemical oxygen demand, chemical oxygen demand, biological organic nutrients (Nitrogen and phosphate) which are insoluble, slowly biodegradable solids, pathogenic and non-pathogenic bacteria and viruses, parasite eggs. Moreover it contains high protein and putrefies fast leading to environmental pollution problem. This indicates that slaughterhouses are among the most environmental polluting agro-industries. Anaerobic digestion is a sequence of metabolic steps involving consortiums of several microbial populations to form a complex metabolic interaction network resulting in the conversation of organic matter into methane (CH 4 ), carbon dioxide (CO 2 ) and other trace compounds. Separation of the phase permits the optimization of the organic loading rate and HRT based on the requirements of the microbial consortiums of each phase. The purpose of this study was to optimize the working conditions for the hydrolytic - acidogenic stage in two step/phase anaerobic digestion of slaughterhouse wastewater. The setup of the laboratory scale reactor was established at Center for Environmental Science, College of Natural Science with a total volume of 40 liter (36 liter working volume and 4 liter gas space). The working parameters for hydrolytic - acidogenic stage were optimized for six hydraulic retention time 1-6 days and equivalent organic loading rate of 5366.43 – 894.41 mg COD/L day to evaluate the effect of the working parameters on the performance of hydrolytic – acidogenic reactor. Result : The finding revealed that hydraulic retention time of 3 day with organic loading rate of 1,788.81 mg COD/L day was a as an optimal working conditions for the parameters under study for the hydrolytic - acidogenic stage. The degree of hydrolysis and acidification were mainly influenced by lower hydraulic retention time (higher organic loading rate) and highest values recorded were 63.92 % at hydraulic retention time of 3 day and 53.26% at hydraulic retention time of 2 day respectively. Conclusion : The finding of the present study indicated that at steady state the concentration of soluble chemical oxygen demand and total volatile fatty acids increase as hydraulic retention time decreased or organic loading rate increased from 1 day hydraulic retention time to 3 day hydraulic retention time and decreases as hydraulic retention time increase from 4 to 6 day. The lowest concentration of NH 4 + -N and highest degree of acidification was also achieved at hydraulic retention time of 3 day. Therefore, it can be concluded that hydraulic retention time of 3 day/organic loading rate of 1,788.81 mg COD/L .day was selected as an optimal working condition for the high performance and stability during the two stage anaerobic digestion of slaughterhouse wastewater for the hydrolytic-acidogenic stage under mesophilic temperature range selected (37.5℃). Keywords : Slaughterhouse Wastewater, Hydrolytic – Acidogenic, Two Phase Anaerobic Digestion, Optimal Condition, Agro-processing wastewater

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The Study of Engineering Control Parameters on Soybean Protein Wastewater by UASB Reactor

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.113-116.1031 ◽

2010 ◽

Vol 113-116 ◽

pp. 1031-1035 ◽

Cited By ~ 2

Author(s):

Yi Sun ◽

Zi Rui Guo ◽

Xiao Ye Liu ◽

Yong Feng Li

Keyword(s):

Chemical Oxygen Demand ◽

Loading Rate ◽

Sewage Treatment Plant ◽

Treatment Plant ◽

Oxygen Demand ◽

Uasb Reactor ◽

Organic Loading Rate ◽

Anaerobic Sludge ◽

Hydrogen Yield ◽

Brown Sugar

In order to disscuss the ability of H2-production and wastewater treatment, a up-flow anaerobic sludge bed (UASB) using a synthesize substrate with brown sugar wastewater was conducted to investigate the hydrogen yield, hydrogen producing rate, fermentation type of biohydrogen production, and the chemical oxygen demand (COD) removal rate, respectively. In this paper, UASB reactor was seeded with sludge from the Harbin Wenchang Sewage treatment plant dewatered sludge. Successful start-up of the reactor was achieved within 40 days at 35±1°C.The concentration of chemical oxygen demand (COD) in influent is increased from 1100mg/L . When it reached maximum, the loading rate was adjusted in a small way and indicators such as VFA, pH and COD in effluent as well as gas production are observed. The most relevant parameters were calibrated with lab-scale experimental data. These experimental results clearly showed that, the most proper corresponding organic loading rate (OLR) and hydraulic retention time (HRT) were 6 kg/ (m3.d)（COD=6000mg/L）and 24 h respectively. Up to 85% of COD was removed and the CH4 production rate of 3.2 m3 / (m3 .d) was obtained. The produced biogas contained 72% of CH4. In the mean time, anaerobic sludge multiplies more faster and exiguous particles appeared. Granules with diameter 1-3mm.

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Enhanced removal of chemical oxygen demand, nitrogen and phosphorus using the ameliorative anoxic/anaerobic/oxic process and micro-electrolysis

Water Science & Technology ◽

10.2166/wst.2012.258 ◽

2012 ◽

Vol 66 (4) ◽

pp. 850-857 ◽

Cited By ~ 3

Author(s):

K. Q. Bao ◽

J. Q. Gao ◽

Z. B. Wang ◽

R. Q. Zhang ◽

Z. Y. Zhang ◽

...

Keyword(s):

Chemical Oxygen Demand ◽

Hydraulic Retention Time ◽

Loading Rate ◽

Oxygen Demand ◽

Synthetic Wastewater ◽

Organic Loading Rate ◽

Organic Loading ◽

Nitrogen And Phosphorus ◽

Operational Conditions ◽

Removal Efficiencies

Synthetic wastewater was treated using a novel system integrating the reversed anoxic/anaerobic/oxic (RAAO) process, a micro-electrolysis (ME) bed and complex biological media. The system showed superior chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) removal rates. Performance of the system was optimised by considering the influences of three major controlling factors, namely, hydraulic retention time (HRT), organic loading rate (OLR) and mixed liquor recirculation (MLR). TP removal efficiencies were 69, 87, 87 and 83% under the HRTs of 4, 8, 12 and 16 h. In contrast, HRT had negligible effects on the COD and TN removal efficiencies. COD, TN and TP removal efficiencies from synthetic wastewater were 95, 63 and 87%, respectively, at an OLR of 1.9 g/(L·d). The concentrations of COD, TN and TP in the effluent were less than 50, 15 and 1 mg/L, respectively, at the controlled MLR range of 75–100%. In this system, organics, TN and TP were primarily removed from anoxic tank regardless of the operational conditions.

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Performance of a Full-Scale Anaerobic Digestion on Bakery Wastewater Treatment : Effect of Modified Distribution System

Jurnal Riset Teknologi Pencegahan Pencemaran Industri ◽

10.21771/jrtppi.2020.v11.no1.p12-18 ◽

2020 ◽

Vol 11 (1) ◽

pp. 12-18

Author(s):

Hanny Vistanty ◽

Rizal Awaludin Malik ◽

Aris Mukimin

Keyword(s):

Anaerobic Digestion ◽

Distribution System ◽

Suspended Solids ◽

Loading Rate ◽

Oxygen Demand ◽

Degradation Process ◽

Full Scale ◽

Organic Loading Rate ◽

Organic Loading ◽

External Circulation

The effectiveness of a full-scale anaerobic digestion pretreatment was evaluated and the effect of wastewater distribution system was determined on the performance of bakery wastewater (BW) treatment. The BW was fed to 3 series of anaerobic compartments as the main degradation process. The distribution system of first compartment was modified and circulated to enhance contact and efficiency. While the effluent of last compartment was partly returned to the first compartment as an external circulation and the other part was further processed in activated sludge under aerobic conditions. The overall system was able to remove chemical oxygen demand (COD), total suspended solids (TSS), and biochemical oxygen demand (BOD) up to 97.7%, 99.7%, and 99.6%, respectively, at maximum organic loading rate of 6.3 kg COD/m3day. High removal of pollutants indicated that modified distribution of circulation is advantageous to the BW treatment

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Impact of organic loading rate and reactor design on thermophilic anaerobic digestion of mixed supermarket waste

Waste Management ◽

10.1016/j.wasman.2021.01.012 ◽

2021 ◽

Vol 123 ◽

pp. 52-59

Author(s):

L. Megido ◽

L. Negral ◽

Y. Fernández-Nava ◽

B. Suárez-Peña ◽

P. Ormaechea ◽

...

Keyword(s):

Anaerobic Digestion ◽

Loading Rate ◽

Reactor Design ◽

Organic Loading Rate ◽

Organic Loading ◽

Thermophilic Anaerobic Digestion

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Development of downflow hanging sponge (DHS) reactor as post treatment of existing combined anaerobic tank treating natural rubber processing wastewater

Water Science & Technology ◽

10.2166/wst.2016.487 ◽

2016 ◽

Vol 75 (1) ◽

pp. 57-68 ◽

Cited By ~ 20

Author(s):

Takahiro Watari ◽

Trung Cuong Mai ◽

Daisuke Tanikawa ◽

Yuga Hirakata ◽

Masashi Hatamoto ◽

...

Keyword(s):

Natural Rubber ◽

Loading Rate ◽

Oxygen Demand ◽

Nitrogen Loading ◽

Post Treatment ◽

Organic Loading Rate ◽

Anammox Bacteria ◽

Rrna Gene ◽

Sequencing Analysis ◽

Reactor Performance

Conventional aerated tank technology is widely applied for post treatment of natural rubber processing wastewater in Southeast Asia; however, a long hydraulic retention time (HRT) is required and the effluent standards are exceeded. In this study, a downflow hanging sponge (DHS) reactor was installed as post treatment of anaerobic tank effluent in a natural rubber factory in South Vietnam and the process performance was evaluated. The DHS reactor demonstrated removal efficiencies of 64.2 ± 7.5% and 55.3 ± 19.2% for total chemical oxygen demand (COD) and total nitrogen, respectively, with an organic loading rate of 0.97 ± 0.03 kg-COD m−3 day−1 and a nitrogen loading rate of 0.57 ± 0.21 kg-N m−3 day−1. 16S rRNA gene sequencing analysis of the sludge retained in the DHS also corresponded to the result of reactor performance, and both nitrifying and denitrifying bacteria were detected in the sponge carrier. In addition, anammox bacteria was found in the retained sludge. The DHS reactor reduced the HRT of 30 days to 4.8 h compared with the existing algal tank. This result indicates that the DHS reactor could be an appropriate post treatment for the existing anaerobic tank for natural rubber processing wastewater treatment.

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Alkali pre-treatment of Sorghum Moench for biogas production

Chemical Papers ◽

10.2478/s11696-012-0298-0 ◽

2013 ◽

Vol 67 (9) ◽

Cited By ~ 12

Author(s):

Karina Michalska ◽

Stanisław Ledakowicz

Keyword(s):

Anaerobic Digestion ◽

Chemical Oxygen Demand ◽

Volatile Fatty Acids ◽

Biogas Production ◽

Oxygen Demand ◽

Total Phenolic ◽

Methane Generation ◽

Pre Treatment ◽

Alkali Hydrolysis ◽

Almost All

AbstractThis work studies the influence of the alkali pre-treatment of Sorghum Moench — a representative of energy crops used in biogas production. Solutions containing various concentrations of sodium hydroxide were used to achieve the highest degradation of lignocellulosic structures. The results obtained after chemical pre-treatment indicate that the use of NaOH leads to the removal of almost all lignin (over 99 % in the case of 5 mass % NaOH) from the biomass, which is a prerequisite for efficient anaerobic digestion. Several parameters, such as chemical oxygen demand, total organic carbon, total phenolic content, volatile fatty acids, and general nitrogen were determined in the hydrolysates thus obtained in order to define the most favourable conditions. The best results were obtained for the Sorghum treated with 5 mass % NaOH at 121°C for 30 min The hydrolysate thus achieved consisted of high total phenolic compounds concentration (ca. 4.7 g L−1) and chemical oxygen demand value (ca. 45 g L−1). Although single alkali hydrolysis causes total degradation of glucose, a combined chemical and enzymatic pre-treatment of Sorghum leads to the release of large amounts of this monosaccharide into the supernatant. This indicates that alkali pre-treatment does not lead to complete cellulose destruction. The high degradation of lignin structure in the first step of the pre-treatment rendered the remainder of the biomass available for enzymatic action. A comparison of the efficiency of biogas production from untreated Sorghum and Sorghum treated with the use of NaOH and enzymes shows that chemical hydrolysis improves the anaerobic digestion effectiveness and the combined pre-treatment could have great potential for methane generation.

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