|کد مقاله||کد نشریه||سال انتشار||مقاله انگلیسی||ترجمه فارسی||نسخه تمام متن|
|5740240||1412161||2018||8 صفحه PDF||ندارد||دانلود کنید|
â¢Phase separation changes could reflect the stability of the anaerobic baffled reactor (ABR).â¢Phase separation changes not only attributed to COD/SO42â ratio variation, but also substrate concentration variation.â¢Phase separation in ABR could avoid the competition between or among SRB, APB, SOB and MPB.â¢The inhibition of sulfide oxidizing was resulted from extracellular S particles accumulation on SOB.
An anaerobic baffled reactor (ABR) with five compartments for treating sulfate-laden wastewater was started up and the multi-phase separation, i.e., acidogenesis, sulfidogenesis, sulfur-production and methanogenesis, was achieved in 130 days of this study. The present study assessed the variations in COD/SO42â ratios as an important factor to evaluate the competition between sulfate-reducing bacteria and the other anaerobic bacteria in the phase-separation system for reactor performance stability. The experiment was divided into Phase I, II and III. In Phase I, the influent COD/SO42â ratio decreased from 13.3 (4Â g COD/0.3Â g SO42â) to 2.0 (4Â g COD/2Â g SO42â) by increasing the sulfate concentration, the above phases shifted to subsequent compartments, the predominant sulfide oxidizing bacteria (SOB) and methane-producing archaea (MPA) shifted to subsequent compartments, the SOB and Methanothrix-like bacteria were coated with S particles and precipitated at a COD/SO42â ratio of 2.0, resulting in an inefficient removal/yield of COD and SO42â/methane, and showed the system to deteriorate. In Phase II, although the COD/SO42â ratio increased to 3.0 (6Â g COD/2Â g SO42â) with an increase in COD concentration, the phase-separation shift to subsequent compartments did not reverse and sulfidogenesis proceeded throughout all compartments, S particles and precipitates coating on SOB and Methanothrix-like bacteria more, sulfide oxidation was inhibited and the effluent quality further deteriorated. In period III, the COD/SO42â ratio further increased to 6.0 (6Â g COD/1Â g SO42â) with a decrease in sulfate concentration, sulfidogenesis and methanogenesis returned to the front compartments and the inhibition of sulfide oxidation was relieved, resulting in an increase in removal/yield of COD and SO42â/methane and the improvement of performance. These results indicate that the influent COD/SO42â ratio and substrate concentration affect the metabolic phase-separation and treatment system stability.
Journal: International Biodeterioration & Biodegradation - Volume 126, January 2018, Pages 37-44