Study On The Process And Mechanism Of Storage Battery Wastewater Treatment

Based on the nature of the storage battery wastewater, such as containing a lot of sulfuric acid ,heavy metal Pb,Mn,Cr,and a little organic pollutants etal, the combination of neutralization precipitation-Fenton coagulation process was studied in order to testify the feasibility of this process. The mechanism of the effective removal of heavy metal Pb at low pH and the treatment of organic pollutant with Fenton process were discussed.In the pretreatment of storage battery wastewater with neutralization precipitation,the pH should be adjust to between 2.0 and 3.0,the stirring speed 200rpm,with the result of COD decreased by about 100mg/L,heavy metal Pb concentration was less than 1.0mg/L,which is consistent with national integrates wastewater discharge standard.In the application of Fenton process for the effluent of avariey conditons to the wastewater COD removal effect after neutralization was further investigated,and the optimum conditions were as following: pH=3.0, H₂O₂ dosage of 600mg/L,FeSO₄·7H₂O dosage was 2.0g/L, with the reaction of 30min at room temperature. Under the optimum conditions,the total COD removal reached 92%, the COD values of the effluent was less than 100mg/L, and the water quality was consistent with national integrated wastewater discharge standard.The technical and economic analysis on the treatment processes were studied. The results suggested that the charge for the treatment of every ton of wastewater was 5.5 yuan and was lower than the common used process of coagulation-dissolved air floatation. The molecular weight of the wastewater changes before and after treatment was investigated using high performance liquid chromatography. The result shows that macromolecular material has been effectively removed, however, the removal of small molecules is not obvious. With the lime as a precipitating agent, under different pH value,the solid precipitation of the Fourier transform infrared spectroscopy was done. Assisted with the Minteq software, the elements in the solid under different wastewater pH valueswere calculated. It is deduced that the removal of lead at low pH was attributed to the adsorption effect of the iron chemical compounds.