Investigation of furfural biodegradation in a continuous inflow cyclic biological reactor

2015 ◽  
Vol 73 (2) ◽  
pp. 292-301 ◽  
Author(s):  
Gholamreza Moussavi ◽  
Mostafa Leili ◽  
Kazem Nadafi

The performance of a continuous inflow cyclic biological reactor (CBR) containing moving media was investigated for the degradation of high concentrations of furfural. The effects of hydraulic retention time (HRT) and furfural initial concentrations (loading rate), as main operating parameters, on the bioreactor performance were studied. The results indicated that the CBR could remove over 98% of furfural and 71% of its chemical oxygen demand (COD) at inlet furfural concentrations up to 1,200 mg L−1 (2.38 g L−1 d−1), a 6-h cycle time and HRT of 12.1 h. The removal efficiency decreased slightly from 98 to 94% when HRT decreased from 12.1 to 10.5 h. The average removal efficiency of furfural and COD during the 345-day operational period under steady-state conditions were 97.7% and 82.1%, respectively. The efficiency also increased approximately 17.2% after addition of synthetic polyurethane cubes as moving media at a filling ratio of 10%.

2004 ◽  
Vol 49 (5-6) ◽  
pp. 281-288 ◽  
Author(s):  
S.J. Kim ◽  
P.Y. Yang

A two-stage entrapped mixed microbial cell (2SEMMC) process which separates nitrification and denitrification phases by the installation of the anoxic and oxic EMMC reactors packed with EMMC carriers was operated with 6, 4, 3, and 2 hours of hydraulic retention time (HRT) using simulated domestic wastewater. The activated sludge was immobilized using cellulose acetate for the EMMC carriers. Similar soluble chemical oxygen demand (SCOD) removal efficiencies of 90-97% were observed for all HRTs (SCOD loading rate of 0.84-2.30 g/L/d) applied. In order to achieve more than 80 % of TN removal efficiency, the HRT should be maintained higher than 4 hours (less than 0.24 g/L/d of TN loading rate). Denitrification was a rate-limiting step which controlled overall TN removal efficiency at TN loading rate of 0.15-0.31 g/L/d although nitrification efficiencies achieved 97-99 %. The effluent TSS of less than 25 mg/L in the 2SEMMC process was maintained at the SCOD loading rate of less than 1.23 g/L/d with back-washing intervals of 5 and 10 days in the anoxic and oxic EMMC reactors, respectively. The minimum HRT of 4 hours is required for high removal efficiencies of organics (average 95.6 %) and nitrogen (average 80.5 %) in the 2SEMMC process with 3 times of recirculation ratio.


2008 ◽  
Vol 57 (7) ◽  
pp. 1047-1052 ◽  
Author(s):  
U. Durán ◽  
O. Monroy ◽  
J. Gómez ◽  
F. Ramírez

The biological elimination of polymeric resins compounds (PRC) such as acrylic acid and their esters, vinyl acetate and styrene under methanogenic and oxygen-limited methanogenesis conditions was evaluated. Two UASB reactors (A and B) were used and the removal of the organic matter was studied in four stages. Reactor A was used as methanogenic control during the study. Initially both reactors were operated under methanogenic conditions. From the second stage reactor B was fed with 0.6 and 1 mg/L·d of oxygen (O2). Reactor A had diminution in chemical oxygen demand (COD) removal efficiency from 75±4% to 37±5%, by the increase of PRC loading rate from 750 to 1125 mg COD/L·d. In this reactor there was no styrene elimination. In reactor B the COD removal efficiency was between 73±5% and 80±2%, even with the addition of O2 and increase of the PRC loading rate, owing to oxygen being used in the partial oxidation of these compounds. In this reactor the yields were modified from 0.56 to 0.40 for CH4 and from 0.31 to 0.60 for CO2. The O2 in low concentrations increased 40.7% the consumption rates of acrylic acid, methyl acrylate and vinyl acetate, allowing styrene consumption with a rate of 0.103 g/L·d. Batch cultures demonstrated that under methanogenic and oxygen-limited methanogenesis conditions, the glucose was not used as an electron acceptor in the elimination of PRC.


2020 ◽  
Author(s):  
Dejene Tsegaye Bedane ◽  
Mohammed Mazharuddin Khan ◽  
Seyoum Leta Asfaw

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


2012 ◽  
Vol 610-613 ◽  
pp. 331-336
Author(s):  
Yuan Hua Xie ◽  
Tong Zhu ◽  
Xiao Jiang Liu ◽  
Hui Liu ◽  
Jin Han

An anoxic-oxic activated sludge process (AOASP) was carried out to degrade nonylphenol polyethoxylates (NPEOs). The carbon source in influent was replaced stepwise by a mixture of nonylphenol decaethoxylate (M-NP10EO). The 2nd-derivative UV-spectrometry was applied to determine the total amount of M-NP10EO in water samples. Chemical oxygen demand (COD) removal efficiency achieves about 85% under the highest M-NP10EO loading rate, and M-NP10EO removal efficiency is about 80%. Denaturing gradient gel electrophoresis (DGGE) results of activated sludges show that the microbe species decrease but gradually stabilize with the increase of M-NP10EO concentration in influent. Fluorescence in situ hybridization (FISH) results of activated sludges showe that the dominant microflora under the highest M-NP10EO loading rate is β-Proteobacteria (35%), followed by α-Proteobacteria (15%), γ-Proteobacteria (5%) and Actinobateria (4%).


2006 ◽  
Vol 53 (6) ◽  
pp. 161-167 ◽  
Author(s):  
S.Y. Ahn ◽  
S.J. Kim ◽  
P.Y. Yang

This study investigated the bio-treatability of PCB contaminated oil for the development of design and operational parameters for the bioreactor. Input of external carbon and nutrient source in the aqueous phase was found to be required for the treatment of polychlorinated biphenyls (PCBs)-contaminated oil. Addition of surfactant was investigated for the emulsification of oil to reduce interference of contact with microorganisms and PCBs. The ratio of surfactant to oil was empirically optimized to 1 : 1. The higher PCB removal efficiency was obtained at 30 days of hydraulic retention time (HRT) in the semi-batch reactor study without cell recycle. The removal efficiency measured in mixed liquor was maintained at over 85% on average at 32±2 °C and 30% at 22±2 °C. More than 0.2 g/l/d of the organic loading rate was suggested to be maintained for various PCB loading rates (0.02–0.6 mg-PCB/l/d). For high biomass retaining and easy collection of treated oil, an Anaerobic Sequencing Batch Reactor (ASBR) was investigated. The removal of Aroclor was observed as more than 50% in the oil phase with 3 days reaction time and about 40% in overall phases, i.e. oil, liquid, biomass phases at 22±2 °C. US EPA verification results on the process performance are included in this presentation.


Archaea ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yue Li ◽  
Qi Hu ◽  
Da-Wen Gao

An integrated anaerobic fluidized-bed membrane bioreactor (IAFMBR) was investigated to treat synthetic high-strength benzothiazole wastewater (50 mg/L) at a hydraulic retention time (HRT) of 24, 18, and 12 h. The chemical oxygen demand (COD) removal efficiency (from 93.6% to 90.9%), the methane percentage (from 70.9% to 69.27%), and the methane yield (from 0.309 m3 CH4/kg·CODremoved to 0.316 m3 CH4/kg·CODremoved) were not affected by decreasing HRTs. However, it had an adverse effect on membrane fouling (decreasing service period from 5.3 d to 3.2 d) and benzothiazole removal efficiency (reducing it from 97.5% to 82.3%). Three sludge samples that were collected on day 185, day 240, and day 297 were analyzed using an Illumina® MiSeq platform. It is striking that the dominant genus of archaea was always Methanosaeta despite of HRTs. The proportions of Methanosaeta were 80.6% (HRT 24), 91.9% (HRT 18), and 91.2% (HRT 12). The dominant bacterial genera were Clostridium in proportions of 23.9% (HRT 24), 16.4% (HRT 18), and 15.3% (HRT 12), respectively.


1989 ◽  
Vol 21 (4-5) ◽  
pp. 167-173 ◽  
Author(s):  
G. F. Nakhla ◽  
M. T. Suidan ◽  
J. T. Pfeffer

An expanded-bed GAC anaerobic reactor was employed to investigate the effect of empty bed detention time, sludge age, and chemical oxygen demand (COD) loading on process performance during the treatment of a coal conversion wastewater. The toxicity of the wastewater to the anaerobic culture was overcome by periodic partial replacement of the reactor medium with fresh GAC. The first phase of this study determined the minimum GAC replacement rate required to successfully treat the wastewater at a COD loading of 11 g-COD/kg-GAC-day. The second phase investigated the dependance of the system performance on hydraulic retention time and the volumetric COD loading rate. Very high organic removal efficiencies, as well as approximately fifty percent conversion of the influent COD to methane gas were achieved even at empty-bed hydraulic retention times as low as 7 hours.


2011 ◽  
Vol 1 (1) ◽  
pp. 27-35 ◽  
Author(s):  
Pramanik Biplob ◽  
Suja Fatihah ◽  
Zain Shahrom ◽  
ElShafie Ahmed

An upflow, partially packed biological aerated filter (BAF) reactor was used to remove nitrogen in the form of ammonia ions by a nitrification process that involves physical, chemical and biological phenomena governed by a variety of parameters such as dissolved oxygen concentration, pH and alkalinity. Dissolved oxygen (DO) and pH were shown to have effects on the nitrification process in this study. Three C:N ratios i.e., 10, 4 and 1 were compared during this study by varying the nitrogen loading while the carbon loading was kept constant at 0.405 ± 0.015 kg chemical oxygen demand m−3 d−1. The removal efficiencies of ammonia linearly increase with a rise of the initial concentration of ammonia-nitrogen. The results of the 115 days' operation of the BAF system showed that its overall NH3-N performance was good, where a removal efficiency of 87.0 ± 2.9%, 89.2 ± 1.38% and 91.1 ± 0.7% and COD removal of 87.6 ± 2.9%, 86.4 ± 2.1% and 89.5 ± 2.6% were achieved for the C:N ratios of 10, 4 and 1, respectively on average, over 6 h hydraulic retention time (HRT). No clogging occurred throughout the period although backwashing was eliminated. It was concluded that the BAF system proposed in this study removed nitrogen by the nitrification process extremely well.


2011 ◽  
Vol 356-360 ◽  
pp. 1055-1060
Author(s):  
Cheng Duan Wang ◽  
Hai Xia Fu

Three folds stable surface flow wetlands (FSSFWs) were operated at different hydraulic loadings of 0.80, 0.53 and 0.27m3/ (m2•d) to treat the decentralized domestic sewage. And we investigated the effect of the hydraulic loading rate (HLR) on the removal efficiency of FSSFWs by measuring five indicators of chemical oxygen demand (COD), total nitrogen (TN), ammonium (NH3-N), total phosphorus (TP) and suspended substance (SS). The research results indicated that the hydraulic loading had great impact on the removal efficiency of FSSFWs, and was looked upon as one crucial factor for FSSFWs design. The removal efficiency of FSSFWs presented a downward trend in various degrees along with the increase of hydraulic loading. Also the hydraulic loading had greater influences on the removal rate of NH3-N and TN than COD, TP and SS. Considering the operation costs, the treatment capacity and the purification effect in this experiment, we could ensure the efficient and stable operation of FSSFWs with HLR at 0.53 m3/ (m2•d) and HRT at 0.4 m3•d-1, which were the most appropriate options.


2012 ◽  
Vol 178-181 ◽  
pp. 376-379
Author(s):  
Fang Li ◽  
Zeng Lu Qi

This paper adopted a 3-stage rotating biological contactor (RBC), while the operating parameters could be controlled properly, this kind of RBC can obtain better removal effect in domestic sewage treatment. At 25oC, when hydraulic retention time (HRT) is 4h ,6h,8h,10h and 12h ,removal rate of COD is 65.14%,86.10%,89.82%,85.93% and 78.58%.HRT fixes on 8h, removal rate of NH3 –N is 75% after adjusting alkalinity. When rotating rate of RBC is 4,6,8,10,12 and 14 r/min, the removal rate of TN is 53.88%,56.78%,60.03%,58.49%,55.32% and 54.87%.RBC also has a good removal efficiency of TP and obtains the removal rate of TP 45%.There is good prospect in domestic sewage treatment with RBC.


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