微电解中和沉淀法处理酸性矿区地下水的研究

【作者】 赵永斌；

【导师】 刘如意； 孙水裕；

【作者基本信息】 广东工业大学 ， 环境工程， 2002， 硕士

【摘要】 本文研究了化学沉淀法和微电解中和沉淀法处理矿山酸性地下水使之达标排放或回用于生产工艺用水要求的工艺条件和作用机理，据此提出了实用可行的酸性地下水净化处理技术。 首先采用化学沉淀处理技术，通过试验确定了影响处理效果的主要因素及其影响规律。经中和沉淀和混凝沉淀处理后，水中的重金属离子得到了有效的去除，去除率都已达到了95％以上，水中除了锑离子浓度以外其他指标都达到了国家排放标准。最佳条件为：PAC用量为30mg／L，pH值6～7左右。通过中和沉淀和混凝沉淀的比较试验表明混凝沉淀法可减少石灰用量，加快渣沉降速度。 采用铸铁和活性炭组成微电解反应器。在微电解静态试验中表明微电解对水中的锑离子可以有效的去除：通过微电解反应的出水和微电解中和反应出水的对比确定了处理工艺的次序：微电解在前，中和沉淀在后。 在微电解动态试验中，主要讨论了进水pH值、停留时间、加碱量、静置时间和搅拌速度、强度对水中重金属离子去除率的影响，在这些单因子试验的基础上，通过正交试验探明了停留时间、加碱量、静置时间三个因素对重金属离子去除率的相互影响。试验表明：在所选水平范围内影响重金属离子去除率的因素主要是停留时间，其次为加碱量，最后为静置时间；此外停留时间、加碱量存在有最佳范围，超出这一范围都不利于重金属离子的去除。由正交试验结果得出试验最佳条件为：在反应器中停留时间为20min；加碱量为2ml。中和反应后的沉淀时间应该是越长越好，但在实际水处理过程中如果沉淀时间越长，沉淀池的容积就会越大。从经济与处理效率两方面综合考虑沉淀最佳值取30min。在此条件下经净化处理后的水完全达到了国家排放标准。 对净化处理后的酸性地下水和原水进行了分选矿试验结果对比。结果表明，处理后出水用于浮选过程中，远远好于未经处理的原水指标，与用自来水的指标十分接近。因此，经微电解中和处理的出水运用于选 矿工艺是完全可行的。 本文还较为详细的探讨了微电解中和处理技术的作用机理。更多还原

【Abstract】 The technical conditions of treating acid mine drainage by chemistry precipitation and micro electrolysis methods as well a- mechanism of micro electrolysis were studied in this paper. And feasible treating technology were given in this paper.Heavy metals in the drainage were efficiently removed in the coagulation precipitation and neutralizing precipitation process, the rate of removal reached 99%.The treated water quality met the demand of water discharge set by the government except the concentration of Sb.The optimization of treatment were: pH6~7; PAC=30mg/L.By comparing the coagulation precipitation and neutralizing precipitation, it was found that the former process could reduce the dosage of lime and quicken the velocity of the sedimentation.The concentration of Sb in the water could be efficiently removed in the micro electrolysis process. The micro electrolysis reactor was filled by activated carbon and cast iron. By observing the results of micro electrolysis static treatment and neutralizing precipitation treatment ,the sequence of the treatment was confirmed: the former micro electrolysis s treatment, the later is neutralizing precipitation.In the micro electrolysis dynamic process, several primary factors influencing the removal rate of the heavy metals were discussed: the pH of the inflow, the retention timeN the adsorption volume in alkali > the deposit timeN the stirring intensity and stirring time. Through the results of orthogonal experiments,it was clear that in the range of the selective factors, the most primary factor influencing the removal rate of the heavy metals was the retention time,the secondary factor is the adsorption volume in alkali, the least was the deposit time. Optimization lied in the former two factors. The optimization of treatment were: the retention time20min, the dosage in alkali2ml. the deposit time30 min. The treated water quality met the demand of water discharge of the government and could be used in the flotation process. It was shown that the treated water has no adverse effect. The flotation index of the treated water was similar to that of the pure water.In addition, the mechanism of micro electrolysis treating technology was discussed in details.更多还原