Abstract:

H₂S was used as the partially alternative nutrient substrate for sludge bioleaching, and the effects of H₂S load on bioleaching treatment efficiency and community diversity were studied. The changes of pH, ORP, heavy metal removal rate and CST were examined, and the community diversity was analyzed. The results showed that H₂S load of 50mL/L with gas flow of 2mL/min could significantly accelerate the bioleaching process, improve the decline rate of pH and maintain a higher oxidation-reduction potential in the sludge system. The addition of H₂S improved dewaterability with CST shortened by 35.8s, had significant effects on heavy metal leaching with the removal rate of Ni, Pb, and Cr increasing by 18.35%, 21.22%, and 13.07% respectively, and promoted the conversion of various heavy metal forms to the easily soluble state. The SEM results showed that H₂S promoted the reproduction of dominant microflora and made the sludge particles larger and compact. High-throughput sequencing showed that the addition of H₂S gaseous substrate strengthened the efficiency of sludge bioleaching treatment, accelerated the trend reducing the number of species, microflora abundance and community diversity in the sludge system, and promoted Proteobacteria as the dominant phylum and Acidithiobacillu as the dominant genus.

Key words: hydrogen sulfide, bioleaching, sludge treatment, heavy metal, dewaterability, community diversity

摘要：

采用H₂S作为污泥生物沥滤的部分替代营养底物，探究了不同的H₂S负荷对生物沥滤处理效能和群落动态的影响。实验考察了生物沥滤过程中pH、ORP、重金属去除率及CST的变化，并进行了群落多样性分析。结果表明：通入气体流量为2mL/min、负荷50mL/L的H₂S，能显著加快生物沥滤进程，提高污泥体系中pH的下降速率，保持更高的氧化还原电位。H₂S的加入不仅改善了脱水性能，CST加快了35.8s，而且对重金属的浸出也有显著的效果，Ni、Pb、Cr的去除率分别提高了18.35%、21.22%、13.07%，同时促进了各种重金属形态向易溶态的转化。电镜结果显示H₂S的加入促进了优势菌群繁殖，并使污泥颗粒变大且紧实。高通量测序显示，H₂S气态基质的加入强化了污泥生物沥滤处理效能，加速了污泥体系中的物种数、菌群丰度、群落多样性的减小趋势，促进变形菌门成为优势菌门，嗜酸菌属成为优势菌属。

关键词: H₂S, 生物沥滤, 污泥处理, 重金属, 脱水性能, 群落多样性