凋落物覆盖下铜尾矿中金属硫化物氧化研究  

Oxidation of metal sulfides in wastelands of copper mine tailings covered with plant residues

作　　者：詹婧 王丹[2] 孙庆业[2] ZHAN Jing;WANG Dan;SUN Qingye(Library,Hefei University of Technology,Hefei 230009,China;School of Resources and Environmental Engineering,Anhui University,Hefei 230601,China)

机构地区：[1]合肥工业大学图书馆,安徽合肥230009 [2]安徽大学资源与环境工程学院,安徽合肥230601

出　　处：《合肥工业大学学报（自然科学版）》2019年第9期1264-1273,共10页Journal of Hefei University of Technology：Natural Science

基　　金：国家自然科学基金资助项目(41171418);合肥工业大学博士学位专项基金资助项目(JZ2015HGBZ0464)

摘　　要：文章选取不同养分含量和灰分碱度的优势植物(白茅和香根草)凋落物,分析其覆盖厚度为5、10、20cm下酸化尾矿和正常铜尾矿的pH值、游离氧化铁质量比以及金属硫化物生物和化学氧化速率等指标,揭示凋落物对铜陵水木冲废弃地尾矿酸化过程的影响。结果表明:凋落物覆盖下,尾矿剖面氧气体积分数显著降低,含水量提高;近中性铜尾矿pH值显著降低,主要为金属硫化物的化学氧化过程,酸化尾矿pH值升高,以生物氧化过程为主;随凋落物厚度增加,pH值降幅(或增幅)增大;凋落物覆盖处理能够抑制尾矿中金属硫化物的化学氧化,引起近中性铜尾矿生物氧化速率的降低和酸化尾矿铁硫氧化微生物活性的提高。总体上凋落物覆盖有利于减缓铜尾矿的氧化进程,凋落物类型对尾矿总氧化速率影响不显著,凋落物的总灰分碱度和尾矿起始pH值是影响尾矿pH值变化的主要因子。The pH, free iron oxide content and metal sulfide biological and chemical oxidation rate of unoxidized tailings and acidic oxidized tailings were analyzed, which were covered with Imperata cylindrica and Vetiveria zizanioides residues with different contents of nutrient and ash alkalinity(5 cm, 10 cm and 20 cm thick layer), in order to reveal the effect of dominant plant residues on the acidification process of Shuimuchong copper tailings in Tongling, Anhui Province. The results showed that the contents of oxygen and water in the mine tailings covered with Ⅰ. cylindrica and Ⅴ. zizanioides residues significantly decreased and increased, respectively. With the coverage of plant residues, the circumneutral unoxidized tailings showed decreasing pH compared with controls, and the increasing thick of plant residues enhanced the pH decline;the tailings were dominated by chemical oxidation. However, the acidic oxidized tailings showed increasing pH with residues coverage, and the pH amplification increased with the thick of plant residues;biological oxidation was the main oxidizing process. The coverage of Ⅰ. cylindrica and Ⅴ. zizanioides residues restrained the chemical oxidation of metal sulfides in mine tailings. Meanwhile, the residues caused a decline of biological oxidation of circumneutral tailings, and an improvement of oxidizing bacteria activity in oxidized tailings. As a whole, the coverage of residues was beneficial to slowing the oxidation rate of mine tailings, and the types of residues have no significant effect on the oxidation rate. Multiple regression analysis showed that the amounts of excessive cations added as plant residues and the initial pH of tailings were main factors affecting the extent of tailings pH changes.

关 键 词：铜尾矿 金属硫化物 植物 凋落物 酸化 

分 类 号：X171.4[环境科学与工程—环境科学]