Operation Characteristic Of Perchlorate Reactor And Properties Of Perchlorate Bio-degradation With Redox Mediators

With the widely use of perchlorate in industry and its tremendous environmental damages.How to properly deal with the perchlorate pollution becomes a hot spot.High efficiency perchlorate removal technology has been widely concerned.Biogranulation is a promising biotechnology due to its advantage of high treatment efficiency.However,the stability of perchlorate granular sludge is relatively poor.Therefore,perchlorate granules were cultured in UASB reactor.Start two reactors UASB1(the rising velocity is 0.55 m/h)and UASB2(the rising velocity is 0.55 m/h),at different rising velocity.The removing ability of perchlorate and the granule characteristics were investigated.Microbe characteristic was analysised by SEM.The granular sludge of perchlorate load capacity in the two reactors were investigated.Through the analysis of the characteristics of granular sludge physicochemical changes,to determine the influence factors which influence the stability of granular sludge.The effect of different mediator to the granular sludge degradation were investigated.The major conclusions are as follows:1)With the process of start running period,adjustment period,and plateau three stages,reactor UASB1 cultivated mature perchlorate granular sludge at about 110 d,and reactor UASB1 was at about 140 d.After complete granular,the ORP of both reactor stability around-400 m V,granule VSS/SS ratio of 0.82 and 0.70,the wet density were both1.04 g/m L,SVI were 5.99 m L/g and 5.97 m L/g,particle size of 1-5 mm,PN/PS ratio of0.30 and 0.31.The mature of perchlorate granular sludge microbial components were mainly for short bacillus.2)Stability in the operation of the reactor,the perchlorate concentration gradually ascending to 800 mg/L,and two reactors perchlorate removal rate were 80% and 90%respectively.The ORP of both reactor were about-250 m V and-350 m V,the p H of effluent water were both stable at around 6.9,VSS/SS ratio went up and then became flat,the wet density were both about 1.0 g/m L,and Zeta potential,RH and EPS content change is obvious.3)Four kinds of water-soluble quinone mediator(α-AQS,AQS,1,5-AQDS and AQDS),and NADH(reduced coenzyme I)analogues(nicotinic acid hydrazide,4N-(hydroxymethyl)niacinamide,niacinamide,and 5N-nicotinoyl glycine)had no acceleration to the degradation of perchlorate.The N-Decanoyl-DL-homoserine lactone had accelerated the degradation of perchlorate at the concentration of 0.4 μg/L,and inhibited the degradation of perchlorate at the concentration of 1 μg/L,2 μg/L,3 μg/L,and4 μg/L.N-Hexanoyl-DL-homoserine lactone and N-Butyryl-DL-homoserine lactone had no effect on the the degradation of perchlorate.In conclusion,perchlorate granules were cultured in this study.The removing ability of perchlorate and the granule characteristics were investigated.And the effect of different mediator to the granular sludge degradation were investigated.The results will provide theory and technique basic for perchlorate removal in groundwater.