Research On The Treatment Of Urban Household Wastewater By Three Dimensional Electrode Method

With the rapid development of the process of urbanization and dramatic increase inurban population and sewage emissions, urban household wastewater pollution is agrowing problem. Three-dimensional electrode method had been widely used in thefield of wastewater treatment due to its high efficiency, no secondary pollution and easyoperation. At present, no research on degradation of one or several organics in urbanhousehold wastewater by three-dimensional electrode method had been reported,although three-dimensional electrode method had been applied in certain urbanwastewater treatment. In this work, the degradation of glucose and amylose wasinvestigated using the three-dimensional electrode method in order to provide thetheoretical basis for the application of carbohydrate degradation．The main researchcontents and results are as follows.The glucose simulated wastewater was treated with the two-dimensional electrodemethod under the conditions of air-in, no air aeration and only nitrogen-in, respectively.Then the three-dimensional electrode method was investigated in contrast totwo-dimensional electrode method. The results indicated that COD removal rate oftwo-dimensional electrode method with air-in was higher than the other two conditions,and the COD removal rate of three-dimensional electrode method reached30.80%,which was obviously higher than traditional two-dimensional electrode method on CODremoval efficiency.Orthogonal tests were carried out to study the influences of the initial pH, cellvoltage, the concentration of Na₂SO₄and the processing time on the treatment ofglucose simulated wastewater （COD₀=500mg/L） by three-dimensional electrode method.The influence of different factors above mentioned on COD removal efficiency was inthe following decreasing sequence: the initial pH＞cell voltage＞the processing time＞the concentration of Na₂SO₄. Further optimization on initial pH, cell voltage, processingtime, concentration of Na₂SO₄, and the distance of main electrodes was conducted andthe optimal conditions for degrading glucose simulated wastewater （COD₀=500mg/L）were as follows: the cell voltage was12.0V, the initial pH was11.0, the processing timewas120min, the concentration of Na₂SO₄was2.5g/L and the distance of mainelectrodes was4cm. The kinetic research showed that the degradation of glucosesimulated wastewater （COD₀=500mg/L） accorded with the apparent second-order reaction kinetics.The1-butanol chelation method was adopted to separate and purify the amylosefrom soluble starch. After a further purification, the amylose was identified by UV-Vistest of its complex formed with iodine. The results turned out to be as follows: the pureamylose could be obtained by the method of1-butanol chelation, the amylose-iodinehad absorption at500～750nm and the λmaxof UV-Vis scan was604nm.The three-dimensional electrode method was applied to treat amylose simulatedwastewater. The results showed that preferable degradation of amylose could beacquired by three-dimensional electrode method, the cell voltage and treating time hadsome effect on COD removal efficiency. The COD removal rate achieved44.00%withthe cell voltage12.0V and the processing time90min. The kinetic research showed thatthe degradation of amylose simulated wastewater （COD₀=500mg/L） accorded with theapparent third-order reaction kinetics.