scholarly journals The role of hydraulic retention time on controlling methanogenesis and homoacetogenesis in biohydrogen production using upflow anaerobic sludge blanket (UASB) reactor and packed bed reactor (PBR)

2015 ◽  
Vol 40 (35) ◽  
pp. 11414-11421 ◽  
Author(s):  
Buchun Si ◽  
Jiaming Li ◽  
Baoming Li ◽  
Zhangbing Zhu ◽  
Ruixia Shen ◽  
...  
2011 ◽  
Vol 393-395 ◽  
pp. 1153-1156
Author(s):  
Zong Lian She ◽  
Lei Lei Li ◽  
Ying Jie Zhu ◽  
Tian Xie ◽  
Li Na Jiang ◽  
...  

The effects on degrading 3-nitrophenol (3-NP) with sodium acetate as co-substrate under the conditions of laboratory-scale upflow anaerobic sludge blanket (UASB) reactor was investigated at an operating temperature of 35±1°C in this study. The results showed that the optimum influent 3-NP concentration was 71.6mg/L when keeping influent COD concentration for 2500 mg/L and hydraulic retention time (HRT) for 30 h. At the stage of reducing influent COD concentration, all of the 3-NP removal rates were more than 95%; while the conversion rate of 3-aminophenol (3-AP) decreased from 61.4% to 0.2%. Meanwhile, the reduction of HRT also had significantly effects on the treatment effect of 3-NP. With the decreases of HRT, COD removal dropped to 49.7% from 82.7%.


2009 ◽  
Vol 33 (4) ◽  
pp. 1139-1144 ◽  
Author(s):  
Aguinaldo Menegassi Pereira Lourenço ◽  
Cláudio Milton Montenegro Campos

The present research was carried out in the Laboratory of Water Analysis at the Engineering Department at Federal University of Lavras (LWAED-UFLA), in order to evaluate the hydrodynamic behavior of a lab-scale upflow anaerobic sludge blanket reactor (UASB) that was continuously fed with liquid effluent from swine manure with solid separation over 2mm. The hydrodynamic parameters were determined by a tracer study, under hydraulic retention time (HRT) of 12 hours, using Lithium Chloride (LiCl) as a tracer. The system was monitored periodically through physical analysis of samples collected at UASB, during the steady-state operational conditions. The physical-chemical analyses were accomplished using a flame photometry. The operational average temperature in the UASB reactor was 23.9ºC .The UASB hydrodynamic parameters determined were: average residence time (<img src="/img/revistas/cagro/v33n4/t4_barra.gif" align="absmiddle">) of 38.3 h, number of dispersion d= 0.27, and the flow type was characterized as dispersed flow of great intensity. This research is of great importance due to the fact that the scaling-up of biological reactors is based on the hydrodynamic behavior, through which the bacterial kinetic is directly influenced, as reported by Saleh (2004).


2010 ◽  
Vol 62 (12) ◽  
pp. 2899-2904 ◽  
Author(s):  
A. Vlyssides ◽  
E. M. Barampouti ◽  
S. Mai ◽  
A. Stamatoglou ◽  
E. Tsimas

This work studied alternative treatment schemes for the vinasse wastewater from wine distilleries aiming at overcoming the problems caused by the high nitrogen and sulfur concentrations. A plexiglas laboratory-scale upflow anaerobic sludge blanket (UASB) reactor of 20 L volume that was operated at 45°C and hydraulic retention time 1 d, was included in all the examined systems. System 1 was the conventional UASB reactor, system 2 was the UASB reactor supplemented with iron. System 3 consisted of the UASB reactor supplemented with iron and a CSTR reactor that operated under the following conditions: Diluted Oxygen 1.2 mg/L, Hydraulic Retention Time 1 d, pH 6.7 and Temperature 45°C. System 3 aimed at converting ammonium directly to dinitrogen gas under anaerobic conditions but it needed to be preceeded by a first partial nitrification step. All systems had high COD efficiencies over 75%. Ferrous iron addition apart from enhancing the performance of systems 2 and 3, it was able to retain all sulphur content of the wastewater as ferrous sulfide stripping the biogas from hydrogen sulfide. System 3 also managed to meet its goal, since it achieved an 86% nitrogen reduction. Conclusively, system 3 seems to be a very promising environmental technology for the treatment of distillery and winery byproducts, as well as industrial wastewater with high sulfur and nitrogen content.


2004 ◽  
Vol 49 (1) ◽  
pp. 95-102 ◽  
Author(s):  
H.H.P. Fang ◽  
Y. Liu ◽  
S.Z. Ke ◽  
T. Zhang

Treating a synthetic wastewater containing phenol as the sole substrate at 26°C, an upflow anaerobic sludge blanket reactor was able to remove over 98% of phenol up to 1,260 mg/l in wastewater with 12 h of hydraulic retention time, corresponding to 6.0 g-COD/(l·day). Results showed that benzoate was the key intermediate of phenol degradation. Conversion of benzoate to methane was suppressed by the presence of phenol. Based on DNA cloning analysis, the sludge was composed of five groups of microorganisms. Desulfotomaculum and Clostridium were likely responsible for the conversion of phenol to benzoate, which was further degraded by Syntrophus to acetate and H2/CO2. Methanogens lastly converted acetate and H2/CO2 to methane. The role of epsilon-Proteobacteria was, however, unclear.


2000 ◽  
Vol 42 (5-6) ◽  
pp. 237-244 ◽  
Author(s):  
Herbert H.P. Fang ◽  
Gong-Ming Zhou

The effects of hydraulic retention time (HRT) and phenol concentration on the degradation of phenol and p-cresol in wastewater were investigated in two respective UASB (upflow anaerobic sludge blanket) reactors with effluent recirculation at 37 °C for over 440 days. After acclimation, nearly all the phenol and p-cresol at moderate concentrations could be degraded without carbohydrate as a co-substrate. Treating a wastewater containing 800 mg/l of phenol and 300 mg/l of p-cresol at HRT ranging 2–12 hours, the first reactor consistently removed 95% of phenol, 65% of p-cresol and 85% of COD at 8–12 hours of HRT; the efficiency, however, decreased at lower HRT. Treating wastewater containing a constant p-cresol concentration of 400 mg/l at 24 hours of HRT, the second reactor was able to remove 75–80% of COD when the phenol was 1200 and 1500 mg/l; the removal efficiency decreased as phenol concentration further increased. High levels of residual phenol and p-cresol in the effluent suppressed the activity of biogranules. The suppression of bioactivity was not permanent. Biomass was able to regain its activity fully after lowering the phenolic concentrations in the wastewater.


2016 ◽  
Vol 73 (12) ◽  
pp. 2959-2970 ◽  
Author(s):  
Raúl Rodríguez-Gómez ◽  
Gunno Renman

Abstract A wastewater treatment system composed of an upflow anaerobic sludge blanket (UASB) reactor followed by a packed-bed reactor (PBR) filled with Sorbulite® and Polonite® filter material was tested in a laboratory bench-scale experiment. The system was operated for 50 weeks and achieved very efficient total phosphorus (P) removal (99%), 7-day biochemical oxygen demand removal (99%) and pathogenic bacteria reduction (99%). However, total nitrogen was only moderately reduced in the system (40%). A model focusing on simulation of organic material, solids and size of granules was then implemented and validated for the UASB reactor. Good agreement between the simulated and measured results demonstrated the capacity of the model to predict the behaviour of solids and chemical oxygen demand, which is critical for successful P removal and recovery in the PBR.


2011 ◽  
Vol 28 (2) ◽  
pp. 139
Author(s):  
A Arshad ◽  
N.H Hashim ◽  
A.K Kashif ◽  
A Bashir

This study was designed to evaluate the feasibility of the treatment of actual textile mill effluent using a upflow anaerobic sludge blanket (UASB) reactor. The main objective of this study was to generate design aids; in terms of organic loading rate (OLR), hydraulic retention time (HRT) versus chemical oxygen demand (COD) and colour removal in the textile effluent using a UASB reactor at neutral pH and constant mesophilic temperature. The COD, colour and total suspended solids concentration of the textile wastes used in the study were analyzed as 5440 mg/l, 3280 mg/l, 2320 units and 955 mg/l, respectively. The UASB reactor was started up by gradually increasing the OLR from 0.2 kg-COD/m3-day to 2.6 kg-COD/m3-day in order to prevent an organic shock to the reactor. Similarly, the hydraulic retention time (HRT) was slowly reduced from 58 h to 8 h to prevent the wash-out of sludge from the reactor. It was observed that more than 80% of COD and colour could be effectively removed at an OLR of 2.2 kg-m3/d and HRT of 20 h. At optimum operating conditions, the effluent volatile fatty acid concentration was observed to be 430 mg/l. The average biogas production observed during this study was 0.34 l/g-CODremoved and it was composed of 58% methane. During the course of maturity of granular sludge, its effective size and settling velocity were observed to increase exponentially as 0.261e0.051x and 1.91e0.017x respectively. The overall observed biomass yield (Yobs) for the experimental period was calculated as 0.049 g-VSS/g-CODrem. This study suggests that the use of a UASB reactor for textile mill effluent is a fairly feasible and viable option. 


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