三维电极法对生活废水的处理研究

发布时间：2018-05-07 21:51

本文选题：三维电极 + 生活废水　；参考：《西安建筑科技大学》2015年硕士论文

【摘要】：三维电极技术是一种新型的电化学技术,因其具有高效、环保和操作简单等特点被广泛应用于废水处理领域。近年来,三维电极技术在废水治理方面的应用研究主要是针对难降解有机废水和含金属离子废水的处理,并且取得了较好的处理效果,而用于处理生活废水的研究报道较为少见。本文采用以石墨为阳极,不锈钢为阴极,柱状活性炭为粒子电极的自制圆筒构型三维电极反应装置开展对模拟生活废水的试验研究,试验考察了在活性炭填充量不同的情况下电压、电解时间、电解质浓度、电解质种类、pH等因素对废水中化学需氧量(COD)、氨氮(NH3-N)、总磷(TP)去除效果的影响,并对其去除机理加以分析。研究结果表明:粒子电极填充高度为500mm时污染物的去除效果高于填充高度为100mm的三维电解体系。在0~50min内增加电解时间有利于去除效率的提高,之后随着时间的延长各指标去除率趋于稳定。粒子电极填充高度500mm,电解50min时COD去除率达到68%,NH3-N、TP的去除率分别达到71.38%、64%。COD和NH3-N的去除率随电压的增加出现峰值,电压增大到9V时,COD和NH3-N的去除率分别为68%、71.38%,当反应电压进一步增加,去除率反而下降;电压对TP的影响趋势与COD、NH3-N不同,5V时TP去除率为64%,之后随电压的增加去除率接近平稳。废水呈中性有利于COD、NH3-N的去除。粒子电极填充高度为100mm的试验中,分别选用氯化钠(NaCl)和硫酸钠(Na2SO4)作电解质,结果表明NaCl体系中的COD、NH3-N去除率高于Na2SO4体系,相同条件下,NaCl作电解质COD、NH3-N的去除率可达到46%、58%,而Na2SO4作电解质COD、NH3-N的去除率只有32%和44%左右。粒子电极填充高度为500mm的试验中,NaCl作电解质,COD、NH3-N的去除率随其浓度的增加呈先升高后下降的趋势。NaCl浓度为0.02mol/L时,COD、NH3-N的去除效果最好,分别达到68%和71.38%,NaCl浓度大于0.02mol/L去除效率反而降低。电解质浓度对TP去除效果影响不明显;NaCl浓度为0.01mol/L时TP去除率70%左右,之后随浓度的增加去除率略微下降。NaCl浓度为0.02mol/L时TP去除率64%。综合分析,本试验在活性炭粒子电极填充高度500mm、电压9V、电解时间50min、废水水质呈中性、NaCl作电解质浓度为0.02mol/L的条件下,对废水中COD、NH3-N和TP的去除效果较好,分别可以达到68%、71%、64%左右。在三维电解装置中,COD、NH3-N的去除主要通过电极的直接氧化作用和中间产物的间接氧化作用完成,因此在不同操作条件下,两者变化趋势相似。TP的去除主要依靠粒子电极层的吸附截留作用。
[Abstract]:Three-dimensional electrode technology is a new electrochemical technology, which is widely used in wastewater treatment field because of its high efficiency, environmental protection and simple operation. In recent years, the application of three-dimensional electrode technology in wastewater treatment is mainly aimed at the treatment of refractory organic wastewater and wastewater containing metal ions, and good results have been obtained. However, there are few reports on the treatment of domestic wastewater. In this paper, a self-made cylindrical three-dimensional electrode reactor with graphite as anode, stainless steel as cathode and columnar activated carbon as particle electrode was used to study the simulated domestic wastewater. The effects of voltage, electrolytic time, electrolyte concentration and electrolyte pH on the removal efficiency of COD, NH _ 3-N ~ (3 +) and TP in wastewater were investigated and the removal mechanism was analyzed. The results showed that the removal efficiency of pollutants was higher when the filling height of particle electrode was 500mm than that in the three dimensional electrolysis system with filling height of 100mm. The increase of electrolytic time in 0~50min is beneficial to the improvement of removal efficiency, and then the removal rate of each index tends to be stable with the prolongation of time. The electrode filling height was 500mm, and the removal rate of COD reached 68.38% NH _ 3-NN ~ (2 +) TP in electrolysis of 50min, respectively. The removal rate of COD and NH3-N reached a peak value with the increase of voltage. When the voltage increased to 9 V, the removal rates of COD and NH3-N were 68.75% and 71.38%, respectively, and the reaction voltage increased further. The effect of voltage on TP is different from that of COD NH _ 3-N. The removal rate of TP is 64 V, and the removal rate is almost stable with the increase of voltage. The neutralization of waste water is beneficial to the removal of CODN. In the experiment with 100mm filling height, sodium chloride (NaCl) and sodium sulfate (Na _ 2SO _ 4) were used as electrolytes. The results showed that the removal rate of COD _ (3) -N in NaCl system was higher than that in Na2SO4 system. Under the same conditions, the removal rate of NH _ 3-N of Na2SO4 electrolyte can reach 46%, while that of Na2SO4 electrolyte is only about 32% and 44%. The removal rate of NH _ 3-N of CODN was increased first and then decreased with the increase of concentration of 500mm. The removal efficiency of NH _ 3-N was the best when the concentration of 0.02mol/L was 0.02mol/L, and the removal efficiency of NH _ 3-N reached 68% and 71.38%, respectively, which was lower than that of 0.02mol/L. The effect of electrolyte concentration on TP removal was not obvious. When the concentration of 0.01mol/L was 0.01mol/L, the TP removal rate was about 70%, and then decreased slightly with the increase of concentration. When the concentration of NaCl was 0.02mol/L, the removal rate of TP was 64%. Comprehensive analysis shows that under the conditions of the electrode filling height of 500mm, voltage of 9V, electrolysis time of 50min, and the concentration of neutral 0.02mol/L as electrolyte, the removal efficiency of COD _ 3-N and TP in wastewater is better, and the removal rate of COD _ 3-N and TP can reach about 68% respectively. The removal of NH _ 3-N in the three-dimension electrolysis unit is mainly accomplished by direct oxidation of the electrode and indirect oxidation of the intermediate product. Therefore, under different operating conditions, the removal of NH _ 3-N is mainly achieved by the direct oxidation of the electrode and the indirect oxidation of the intermediate product. The removal of TP mainly depends on the adsorption and retention of particle electrode layer.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X799.3

【参考文献】