摘要
施用有机肥能够降低污染土壤重金属溶解性和生物可利用性,但在淹水厌氧等环境中,有机肥会分解产生大量低分子有机酸,会抑制嗜酸性硫杆菌的生物活性.通过摇瓶实验研究了低分子有机酸对硫杆菌的毒害抑制效果和不同硫杆菌对各类有机酸的耐受水平.结果表明,纯体系培养下,A.ferrooxidans和A.thiooxidans活性抑制率在72 h内达到90%以上,所需甲、乙、丙、丁酸最低浓度分别为41.2、78.3、43.2、123.4 mg·L^(-1)和81.9、230.4、170.1、123.4 mg·L^(-1).其中,甲酸对A.ferrooxidans和A.thiooxidans的抑制作用最显著,A.thiooxidans相比A.ferrooxidans对4种有机酸具有更高的耐受性.新鲜重金属污染土壤在生物酸化初期(0 h)加入4种有机酸对后续土壤酸化过程影响较小,但12 h后加入有机酸却能使土壤生物酸化基本停止,导致土壤重金属脱除率大幅度下降.这为有机肥改良重金属污染土壤的生物修复可行性提供一定理论依据.
Application of organic fertilizer can reduce the solubility and bioavailability of heavy metals in contaminated soil, but in the flooded anaerobic environment, organic fertilizer will be decomposed to produce a large number of low molecular organic acids, which can inhibit the biological activity of Acidithiobacillus species. Batch cultures studies showed that the monocarboxylic organic acids including formic acid, acetic acid, propionic acid, and butyric acid exhibited a marked toxicity to Acidithiobacillus species, as indicated by that 90% of inhibitory rate for Fe^2＋ and So oxidation in 72 h were achieved at extremely low concentrations of 41.2 mg·L^-1, 78.3 mg·L^-1, 43.2 mg·L^-1, 123.4 mg·L^-1 and 81.9 mg·L^-1, 230.4 mg·L^-1, 170.1 mg·L^-1, 123.4 mg·L^-1, respectively. Of these organic acids, formic acid was the most toxic one as indicated by that Fe^2＋ and So oxidation was almost entirely inhibited at a low concentration. In addition, it was found that Acidithiobacillus ferrooxidans was more sensitive to low molecular organic acids than Acidithiobacillus thiooxidans. What＇s more, there was little effect on biological acidification process of heavy metal contaminated soil when organic acids were added at initial stage （0h） , but it was completely inhibited when these acids were added after 12 h of conventional biological acidification, thus decreasing the efficiency of heavy metals dissolution from soil.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2016年第5期1960-1967,共8页
Environmental Science
基金
国家自然科学基金项目(21277071
41371476)
中央高校基本科研业务费专项(2722013JC095)
关键词
低分子有机酸
嗜酸性氧化亚铁硫杆菌
嗜酸性氧化硫硫杆菌
生物酸化
重金属
low molecular organic acids
Acidithiobacillus ferrooxidans
Acidithiobacillus thiooxidam
biological acidification
heavy metal
