Research On Coal Washing Wastewater Treatment Method Used In Electro-Coagulation

Coal washing wastewater that was produced by the coal industry,industrial wastewater,the nature of such wastewater difficulted to precipitate,serious pollution and waste water,and other characteristics,were one of the main sources of pollution.These study was mainly aimed at coal-fired power plants in order to make better used of coal power generation and water rinse,reducing the surface of coal impurities and improving the utilization rate of coal produced in the process of coal washing wastewater.In order to be able to recycle and effectively treat coal washing waste water to provide a feasible and effective economic and technical programs,achieving the closed cycle of coal washing wastewater,reducing the impact of coal washing wastewater on the surrounding environment,so the removal effect of such wastewater had to study deeply.China's coal washing wastewater treatment methods commonly were the addition of coagulants and flocculants and other pHarmaceutical methods for processing,and these method of adding the agent have been caused secondary pollution and other issues.Electrocoagulation was an electrochemical treatment method which was used of iron or aluminum ions in the formation of hydroxide flocculation in electrolysis to polymerize colloidal substances in water to make water purification.Compared with the traditional method,it had stable,high efficiency,no need to add chemical substances and other significant features.Therefore,these paper had tried to electro-flocculation of coal-washing wastewater treatment depth,to explore the effect of its water quality.Test had used iron plates for concentration of suspended solids SS,turbidity and pH value of the main indicators,for ammonia,COD,sulpHides and heavy metals(iron,manganese,copper,zinc,nickel,chromium,cadmium,lead)supplement.Respectively,by changing the initial pH value,electrolysis time,plate spacing,amperage,electrode materials and processing parameters with and without aeration conduced sequencing batch tests,preliminary researched on the influence of the parameters of the treatment effect;Respectively by changing the hydraulic the residence time,plate number(pitch),current intensity and concentration of the influent parameters such as continuous flow test,in-depth studyed of the impact of various parameters on the amount of treatment effect;The optimum operating conditions and the relationship between the parameters were obtained by orthogonal testElectrolysis time was too short leading to poor flocculation,and electrolysis time was long leading to reduce the electrolysis current efficiency,also making to increase the consumption and processing costs.Sequencing Batch tests could initially learn:initial wastewater without testing,without aeration device treatment effect relatively good,iron aluminum plate processing basically the same effect,considerating the economic useing plates,with electrolysis time increasly,the concentration of suspended solids and increased and reaching the maximum at the time of 1.5h,after a period of time remains plate spacing the greater the effect of the treatment badly,with the increase of the intensity,the process betterly;Continuous-flow experiments could gain insight:HRT having be controlled within 30min of appropriate,in the same device electrode distance smaller and number plates,handle better,so plate spacing to 2cm and plate number of 12-24 when 1,with the increase of current intensity,the concentration of suspended solids removal increasely,considering the relationship between energy consumption,current intensity 15A the current density was 18.22 A/m2,the influent concentration having not be too large,so stripping out the best at 300mg/L.Single factor analysis that inculded HRT,plate spacing or number of the current strength of these three factors orthogonal experiment,through final overall balance,the experimental results the best solution for HRT 15min,plate spacing of 1cm or plate number of 24 and a current density 18.22 A/m2.Experiments by the size of the electrolysis voltage and current to calculate the consumption of wastewater treatment washing size,results of the electrical power consumption flocculation treatment of waste water for coal washing was 1.875 kw · h/m3.In these paper,the using of electro-flocculation method for coal washing wastewater treatment,the test results for the concentration of suspended solids removal rate was 86.7%,98.6%turbidity removal,water pH = 7.5,having some sulfides and COD removal efficiency of ammonia and almost no heavy metals.