【作者】 苏宇；

【导师】 彭书传；

【作者基本信息】 合肥工业大学 ， 环境科学， 2010， 硕士

【摘要】 本文在无外加中和剂的情况下,以活性污泥为硫酸盐还原菌(SRB)的接种菌群,考察了接种菌群对酸性废水初始pH的耐受范围,分别添加稻草、油菜秆、乙醇、乙酸和葡萄糖等五种有机物,评价了硫酸盐还原菌对这五种有机碳源的可利用性,深入研究了硫酸盐还原菌以稻草和污泥为营养源处理酸性矿山排水(pH=2.5)的过程,并分析了稻草和污泥投加量对处理过程的影响,以期为低成本原位处理酸性矿山排水(AMD)提供指导和方法。在不投加化学中和剂的情况下,以污泥为硫酸盐还原菌的接种菌群,在初始pH为3～7的模拟矿山排水中,经过短期培养可实现SRB驯化及硫酸盐还原;而在初始pH为2的条件下,SRB活性受到抑制,经过三周培养无明显硫酸盐还原。分别向体系中添加五种有机碳源后,仅投加了乙醇或稻草的体系可在短期内实现硫酸盐还原,其中投加乙醇的体系中SO42-还原率最高为94.5 %,其次为稻草,SO42-还原率为54.2 %。对照实验(仅含污泥的体系)中硫酸盐浓度仅降低了约50 mg/L,说明外加碳源可促进体系中SRB驯化及硫酸盐还原。SRB以稻草和污泥为营养源处理人工模拟酸性矿山排水时,污泥中的碱性物质可在反应之初迅速中和废水的部分酸度,使反应体系pH值升至适宜SRB生长的水平。SRB以污泥为碳源时硫酸盐还原率较低,添加稻草可促进反应体系中硫酸盐的还原,使硫酸盐还原率从65.9 %升至79.2 %。含污泥的反应体系中铜离子去除率均高于99 %,SRB驯化前铜离子的去除主要归因于污泥的吸附作用。改变体系中污泥和稻草的投加比例,一方面影响着体系中pH的变化,因为反应基质的酸中和能力主要与污泥的投加量或浓度有关。另一方面,污泥和稻草的投加比例直接决定供给SRB利用的C、N和P的水平。当污泥和稻草的投加比例为0.077时,体系中C:N:P比值为92:3.2:1,硫酸盐还原率最高为79.8 %,说明当pH不是抑制SRB活性的因素时,在此投加比例下硫酸盐还原菌还原硫酸盐的能力最强。以稻草和污泥为营养源可实现低成本酸性矿山排水处理,这对于矿山环境的原位修复有实际意义。更多还原

【Abstract】 In this thesis, a series of experiments were conducted to offer a low cost and effective way for in situ acid mine drainage (AMD) treatment. Sewage sludge was used as sulfate-reducing bacteria (SRB) seed and the tolerance degree of inoculation bacteria to initial pH of acid waste water was tested. Five organic materials (rice straw, rape straw, ethanol, acetate and glucose) were selected to investigate how well these promote sulfate reduction by SRB. A further research was carried out to study the process of SRB biological treatment of synthetic acid mine drainage (pH=2.5) by using rice straw and sewage sludge as nutrition sources, and to analyze the effect function of dosage of these two organic substrates.Batch experiment results showed that when sewage sludge was used as SRB seed, SRB acclimation was achieved and sulfate reduction was detected in reactors containing waste water with initial pH 3～7 after a short-term incubation, but three weeks later in the reactor containing waste water with initial pH 2, no sulfate reduction was observed because the activity of SRB was inhibited. A small quantity (~ 50 mg/L) sulfate was reduced in the control reactor containing only sewage sludge. When the five organic materials were added, ethanol was most effective in promoting sulfate reduction (94.5 %), followed by rice straw (54.2 %), the other three materials generally showed low reactivity. This suggests that SRB acclimation and sulfate reduction can be enhanced by additional organic carbon source.A further research indicated that certain amount of alkaline substance present in sewage sludge could neutralize acidity of synthetic acid mine drainage on the first day of experiment, elevating pH value from the initial 2.5 to around 5.4~6.3 and achieving suitable pH condition for SRB growth. Sewage sludge contained fewer biodegradable organic substances, reactive mixture with single sewage sludge showed the lowest sulfate reduction (65.9 %). When the single sewage sludge was supplemented with rice straw, SRB reducing sulfate was enhanced (79.2 %), because the degradation rate of rice straw was accelerated by the specific bacteria in sewage sludge, providing relatively abundant carbon source for SRB. Metal removal efficiency in all reactors was as high as 99 % for copper, early copper removal was mainly attributed to the adsorption capacity of sewage sludge prior to SRB acclimation. The proportion of sewage sludge and rice straw could have effect on both pH value and the three nutritious elements (carbon, nitrate and phosphate) present in reaction system, because the acid neutralization capacity of sludge depended on its dosage or concentration, and the available level of C, N and P was determined by the proportion of sewage sludge and rice straw. When the dosing ratio of sewage sludge and rice straw was up to 0.077, sulfate reduction rate reached 79.8 %, this indicated that C:N:P with a ratio of 92:3.2:1 was most suitable for SRB growth and promoting sulfate reduction as the activity of SRB was not inhibited by pH .It is feasible for using rice straw and sewage sludge as nutrition sources for SRB treating acid mine drainage at a low cost, this may have significant implication for in situ bioremediation of mine environment.更多还原