摘要
采用半连续实验方法,研究了中温厌氧条件下硫酸盐的还原行为及产生抑制作用的机理.实验结果表明,SO_4^(2-)在厌氧体系中被硫酸盐还原菌(SRB)全部或部分还原为硫化物,其还原率与SO_4^(2-)累积加入浓度有关.还原产物的形态与体系中pH值有关,较高的pH值(7.6—8.4)使体系中H_3S含量下降.SO_4^(2-)对厌氧体系的抑制与SO_4^(2-)还原过程中SRB与产甲烷菌(MRB)的底物竞争及还原产物的毒性相关.前者受COD/SO_4^(2-)比值的影响,比值大于7,对厌氧体系只产生轻度抑制作用.而后者与沼气中H_2S含量有直接关系,沼气中H_3S含量小于40mg/L时,基本不产生抑制作用.
The behavior of sulfate and mechanism of its inhibitory effect was studied under mesophilic condition with semi-continuous bioassay. The results showed that the reduction rate of sulfate was progressively decreased with the increase of sulfate concentration in the substrate when the concentration was greater than 500 mg/L. The species of reduction products of sulfate (H2S,HS-, S2-) were related to the pH value of the digestion solution. The concentration of hydrogen sulfide may decrease in a relatively high pH value(7.6-8.4). In addition, the results also showed that the substrate (hydrogen, acetate) competition of sulfate reducing bacteria (SRB)with methane producing bacteria (MPB) and sulfides toxicity were two major reasons causing the inhibitory effect on anaerobic digestion. The substrate competition of SRB and MPB was related to the ratio of COD value to sulfate concentration. The anaerobic system would be slightly inhibited when COD/SO_4~2- was greater than 7 .The sulfide toxicity to methanogens was directly related to H2S concentration in the gas phase, there was no inhibition when H2S concentration was less than 40 mg/L.
出处
《环境科学学报》
CAS
CSSCI
CSCD
北大核心
1993年第4期414-419,共6页
Acta Scientiae Circumstantiae
基金
国家"七五"攻关课题报告
关键词
硫酸盐
还原
抑制作用
SRB
sulfate reduction
inhibitory effect. sulfite
sulfate reducing bacteria (SRB)
methane producing bacteria (MPB).
