摘要
环境中砷的存在往往对人类健康产生不利影响,从而一直受到人们的广泛关注。在厌氧条件下硫酸盐还原菌(SRB)利用有机物还原硫酸根生成硫化物,进一步通过硫化物与溶液中砷反应产生沉淀从而实现砷的最终去除。为了探讨不同因素对SRB除砷的影响,该实验研究了在不同初始pH值、碳源和初始砷浓度条件下的SRB活性及其对砷的去除效果。提取在UASB反应器中长期驯化的富含SRB的厌氧污泥进行批次实验。研究表明,在选取乳酸、乙酸、葡萄糖作为不同外加碳源的对比实验中,微生物利用乳酸作为基质反应相对缓慢(COD分解速率低),SRB具有较高的反应活性(对硫酸根去除率最高),同时保持较好的砷去除率(大约60%);SRB利用不同有机物反应过程中产生碱度导致系统内pH逐渐升高,其中以乳酸作为碳源时系统内pH升高到8.5左右;随着初始pH的升高,砷的去除效果降低,硫化砷沉淀在弱酸性条件下更易稳定存在;随着初始砷浓度的增加,SRB的活性受到抑制,当初始砷浓度达到40 mg·L^(-1)时,SRB基本失去反应活性;利用驯化污泥除砷过程中,部分砷价态发生了变化。
The presence of arsenic in the environment is of public concern due to its toxicity in humans.Under anaerobic conditions sulfate-reducing bacteria（ SRB） can reduce sulfate to products such as H2 S,which reacts with arsenic to form precipitates. The influences of different factors such as initial pH,carbon source,and initial arsenic concentration on the activity of SRB and their removal efficiency of arsenic were investigated. Batch experiments were carried out by using acclimated anaerobic sludge rich in SRB in a long-term operational UASB reactor. Results show that the utilization of lactate as carbon source for SRB leads to a slower COD degradation rate than the utilization of acetic acid or glucose as carbon source. Moreover,SRB maintain a relative high sulfate removal and a high arsenic removal rate when using lactate as carbon source. The pH in the system increased to8. 5 with lactate as carbon source since the utilization of organic matter by SRB leads to a gradual increase of pH in the reaction system. The removal efficiency of arsenic decreased with high initial pH,and arsenic sulfide was more stable as precipitate under weakly acidic conditions. Increasing the initial arsenic concentration leads to inhibition of SRB activity,and SRB lost their activity completely when the initial arsenic concentration reached 40mg·L^（-1）. The arsenic species changed during biological arsenic removal by acclimated sludge.
出处
《环境工程学报》
CAS
CSCD
北大核心
2016年第7期3898-3904,共7页
Chinese Journal of Environmental Engineering
基金
国家自然科学基金资助项目(21107100)
郑州市国际科技合作与交流项目(121PPTGG360-9)
郑州市国际科技合作与交流项目(141PGJHZ35)
关键词
硫酸盐还原菌
砷
不同碳源
PH
三价砷氧化
sulfate-reducing bacteria
arsenic
different carbon sources
pH
arsenite oxidation
