Experimental Study On Treating Micro-polluted Water Based On Electrocoagulation

Due to the population growth,development of urbanization and industrialization,the demand for water is increasing in human society,leading to a series of problems such as water shortage,water environment deterioration,flood disaster and so on.Unconventional water resources utilization has become a hot topic because it can effectively alleviate these problems.In the field of unconventional water resources utilization,rainwater and flood management system is mainly used for the collection and utilization of rainwater,so it has been widely studied in many countries,forming a number of technical systems and management concepts.At present,the research on stormwater management technology is only focused on the collection&utilization of rainwater resources and the source control of pollutants,the study on water quality in stormwater management technology improvement is less.The electrocoagulation water treatment technology's device is simple and low cost,easy operation and without human duty,so it has been widely used in water with high concentration pollutants such as industrial wastewater and domestic wastewater,but the study on electrocoagulation of micro-polluted water is few.Therefor,this paper discussed the practical results of electrocoagulation technology treating micro-polluted water.First introduced the electrocoagulation micro polluted water test device&test operation,designed the experimental groups,selected the water quality analysis indexes and testing instruments,analyzed the original water quality;then the influences of various factors on the treatment effect were analyzed by batch&continuous test,on this foundation,the optimum reaction conditions were confirmed,and the treatment effect was analyzed under the optimal reaction conditions;finally,the optimal applications of batch&continuous treatment were determined by comparing the best reaction conditions,the removal results&efficiency of pollutants and the operating cost of the reactors.The effect of electrode spacing,current density and reaction time on the removal efficiency of pollutants was analyzed by batch test,under the experimental conditions of this dissertation,the best reaction condition is determined as the electrode spacing of 1.5 cm,current intensity of 0.6 A,reaction time is 25 min.Under this situation,the removal rates of color,turbidity,SS,COD and TP were 76.47%,80%,89.29%,57.14%and 78.41%respectively.After treatment,the parameter values of effluent basically meet the water quality standard for scenic environment use(GB/T 18921-2002),water quality standard for urban miscellaneous water consumption(GB/T 18920-2002),water quality standard for domestic miscellaneous water consumption(CJ 25.1-89),and environmental quality standards for surface water of class ?(GB 3838-2002).The influence of the electrode distance,current density and discharge on the wastewater treatment efficiency was analyzed by continuous experiment,under the experimental conditions of this paper,the optimum reaction condition is determined as electrode gap of 1.5 cm,current intensity of 0.5 A and discharge of 2 mL/s.The removal rates of color,turbidity,SS,COD and TP were 63.61%,76.79%,60.87%,11.76%and 61.54%respectively under this condition,except color,other water quality indicators can meet the relevant water quality standards and meet environmental quality standards for surface water of class ?(GB 3838-2002).It is found that there are some similarities of optimum reaction conditions between the batch and continuous treatment methods,but they are not consistent.The effect of wastewater treatment in batch test is good and the device operating cost is relatively low,but the treatment efficiency is slightly lower;the effect of continuous treatment is slightly poor and the operating cost of the unit is much lower,but the treatment efficiency is high.Therefore,the batch processing is suitable for the situation that the water quantity is small and the pollution degree is high;the continuous treatment is suitable for the situation that the water quantity is large,the pollution degree is low or the water quality requirement is low.Micro-polluted water treatment with electrocoagulation method is feasible,with advantage of good treatment effect and low cost,the treated effluent can meet the requirements of daily miscellaneous water requirements.Follow-up this method can be combined with the rain and flood management technology to realize the fine processing of rain&flood resources,and expand the utilization of these resources.