Effects of Air/Liquid Ratio on Treatment Efficiency of Textile Wastewater in a Biological Aerated Filter Reactor

2013 ◽  
Vol 316-317 ◽  
pp. 241-244 ◽  
Author(s):  
Xu Jie Lu

A biologically aerated filter (BAF) is a novel, flexible and effective bioreactor that provides a small footprint process option at various stages of wastewater treatment. Double layers of activated carbon and ceramsite were applied in the biological aerated filter reactor. An experiment was conducted under laboratory conditions to investigate the treatment efficiencies at different air/liquid ratios. The experimental results obtained showed that air/liquid ratio had a greater effect on NH4+–N removal than COD removal. More than 80% ammonia nitrogen was removed at 2 of air/liquid ratio. However, less than 50% COD was removed at 2 of air/liquid ratio.

2013 ◽  
Vol 777 ◽  
pp. 117-121
Author(s):  
Dong Wang ◽  
Li Ping Qiu ◽  
Chun Hui Guo ◽  
Qiang Liu

The performance of three BAFs with zeolite, activated carbon and anthracite media for the treatment of polluted Huaihe raw water were investigated. All three BAFs performed promising permanganate index (CODMn) and ammonia nitrogen (NH4+-N) removal efficiency as well as the turbidity removal was over 60%. Moreover, the CODMn and NH4+-N removal in the three BAFs were affacted by the characteristics of filter media. Activated carbon and anthracite had better CODMn removal than zeolite. Zeolite had the best NH4+-N removal, followed by activated carbon, anthracite was the worst.


2011 ◽  
Vol 1 (3) ◽  
pp. 160-171 ◽  
Author(s):  
Pramanik Biplob ◽  
Suja Fatihah ◽  
Zain Shahrom ◽  
Elshafie Ahmed

This paper examines on-off systems and automatic monitoring and control of a biological aerated filter to identify the end point of nitrification and denitrification processes, and chemical oxygen demand (COD), ammonia-nitrogen removal (NH3-N) and aeration savings. Oxidation-reduction potential (ORP), pH and dissolved oxygen (DO) were measured on-line and chemical parameters were measured in the wastewater. The ‘nitrate knee’ in the ORP profile was characterised by a breakpoint at average 160 min, representing the complete removal of NO3-N, i.e. the end of the denitrification period, as well as the end of the nitrification period was clearly shown in the pH profile (ammonia valley) at average 210 min for all C/N ratios. The NH3-N removal efficiencies were 92.30, 97.57 and 98.02% whilst the COD removals of 95.06, 96.38 and 97.56% were achieved for the C/N ratios of 10, 4 and 1 respectively. Therefore, the on-off control was operated at average 230 min for aeration time and 130 min for the anoxic period. Thus significant improvements can be achieved with respect to the continuous aeration strategy, and average operational costs reduced by 36.11%. The study showed that an on-off controller can easily be implemented in wastewater process-control, and monitoring systems improve effluent quality and reduce energy consumption.


2012 ◽  
Vol 441 ◽  
pp. 589-592
Author(s):  
Zhi Min Fu ◽  
Yu Gao Zhang ◽  
Xiao Jun Wang

A combined process of biological wriggle bed and ozone biological aerated filter was utilized to treat textile wastewater. Results showed that COD removal efficiency was almost 90.4%. The average effluent COD was 85.87 mg/L. The effluent colority was 64-32 times. This study indicated that the combined process is potentially useful for treating textile wastewater.


2010 ◽  
Vol 61 (3) ◽  
pp. 789-796 ◽  
Author(s):  
S. González-Martínez ◽  
S. Piña-Mondragón ◽  
Ó. González-Barceló

The main objective of this research was to determine the feasibility to treat the azo dye direct blue 2 together with municipal wastewater in a biological aerated filter (BAF) using lava stones as support of the microorganisms and under combined anaerobic/aerobic conditions. A 3 m high pilot biological aerated filter was fed with municipal wastewater and, after several weeks, the azo dye direct blue 2 was added to the wastewater to reach a final concentration of 50 mg/L (34 mgCOD/L). Under continuous operation, two strategies were tested: Alternating aeration (12 h anaerobic and 12 h aerobic) and combined aeration (the lower part of the filter anaerobic and the upper part aerobic). The results indicate that municipal wastewater acted as a good electron donor resulting in satisfactory COD and dye removal rates. Better dye removal (61%) was obtained with combined aeration than with alternating aeration (45%). After beginning the azo dye addition, the COD removal rates decreased from 87 to 81% for both alternating and combined aeration procedures. The average ammonia nitrogen removal, without the addition of the dye, was 73% and increased to 90% shortly after beginning the dye addition, then it decreased to 81% during the combined aeration period. Excellent nitrification was observed in the upper aerobic part of the filter. For the combined aeration phase, the conditions change from anaerobic to aerobic does not seem to affect the behavior of the COD and TSS curves.


2013 ◽  
Vol 726-731 ◽  
pp. 1940-1944 ◽  
Author(s):  
Liang Shen ◽  
Han Xiao ◽  
Wan Qiu Yang ◽  
De Ren Miao ◽  
Xiao Ming Li

Using coagulation and sedimentation process in the advanced treatment of urban secondary effluent which can be recycled to circulating cooling water system in power plant is only perform well on CODCrand turbidity removal. But the concentrations of organic matter and NH3in effluent can not meet the requirements of circulating cooling water. Therefore, in this study, the feasibility of biological aerated filter (BAF) as a pretreatment enhancing coagulation and sedimentation process was discussed. Achieved by controlling the two operating modes: (1) secondary effluentcoagulation and sedimentationeffluent; (2) secondary effluent BAFcoagulation and sedimentation effluent.The results show that the BAF pretreatment removes ammonia nitrogen effectively, and the turbidity and CODCrof effluent of BAF-coagulation sedimentation process is much lower than individual coagulation and sedimentation process. The final effluent qualities meet the requirements of circulating cooling water system in power plant.


2011 ◽  
Vol 183-185 ◽  
pp. 432-436
Author(s):  
Xia Wang ◽  
Yong Qiang Wu

On the up-flow biological aerated filter to remove COD and NH3-N were studied the effect and contrast in various stages of finding the optimal operating conditions, so as to achieve energy conservation, the purpose of reducing operating costs. Through experiment studied that the variation of air-water ratio, hydraulic loading, organic concentration in the removal of COD and NH3-N effects, observe and analyse the change of COD and NH3-N removal and the characteristics of microorganisms of filter’s different height. The results showed that COD and NH3-N removal are high under the condition of air-water ratio 4:1~5:1, hydraulic loading 1~2 m3/ (m2●h), organic concentration 300~400 mg/L. The concentration of COD and NH3-N of effluent which are treated by biological aerated filter can meet with second degree discharging standards.


2016 ◽  
Vol 73 (8) ◽  
pp. 2031-2038 ◽  
Author(s):  
L. Y. Fu ◽  
C. Y. Wu ◽  
Y. X. Zhou ◽  
J. E. Zuo ◽  
Y. Ding

In this study, petrochemical secondary effluent was treated by a 55 cm diameter pilot-scale biological aerated filter (BAF) with a media depth of 220 cm. Volcanic rock grains were filled as the BAF media. Median removal efficiency of chemical oxygen demand (COD) and ammonia nitrogen (NH3-N) was 29.35 and 57.98%, respectively. Moreover, the removal profile of the COD, NH3-N, total nitrogen and total organic carbon demonstrated that the filter height of 140 cm made up to 90% of the total removal efficiency of the final effluent. By gas chromatography–mass spectrometry, removal efficiencies of 2-chloromethyl-1,3-dioxolane, and benzonitrile, indene and naphthalene were obtained, ranging from 30.12 to 63.01%. The biomass and microbial activity of the microorganisms on the filter media were in general reduced with increasing filter height, which is consistent with the removal profile of the contaminants. The detected genera Defluviicoccus, Betaproteobacteria_unclassified and the Blastocatella constituted 1.86–6.75% of the identified gene, enhancing the COD and nitrogen removal in BAF for treating petrochemical secondary effluent.


2014 ◽  
Vol 15 (2) ◽  
pp. 348-355
Author(s):  
Hui Feng ◽  
Fu-yi Cui ◽  
Yi-zhong Xie ◽  
Yan Wei ◽  
Zhi-wei Zhao

The enhancement effect of polyethylene (PE) surfaces modified with poly(lactic acid) (PLA) on formation of nitrifying biofilms in biological aerated filter (BAF) was investigated in this study. X-ray photoelectron spectroscopy, scanning electron microscope, and protein absorption analysis revealed that modified PE surfaces produced active groups, including carboxyl (O═C─O), hydroxyl (C─OH), and carbonyl (C═O), increased surface roughness, and enhanced the adsorption of both the bovine serum albumin and fibrinogen. During the startup period of 33 days, the average removal rates of ammonia nitrogen (NH3-H) were 68 and 72% before and after modification which were 36 and 43% for total nitrogen, 47 and 45% for total organic carbon. The results of denaturing gradient gel electrophoresis experiments demonstrated that modified carriers adsorbed and gathered more species of bacteria on surfaces. Thus, surface modification of PE suspended carrier by PLA improved the efficiency of reactor startup for drinking water treatment.


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