CLT Acid Waster By Fenton Oxidation-coagulation Pretreatment Experimental Study

CLT acid production wastewater is a type of toxic and refractoryorganic wastewater. There is no effective way to treat CLT acid wastewater. Traditional primary and secondary treatment processes can not meet the requirement to remove contaminants from the CLT acid wastewater. In this study, the realCLT acid production wastewater taken from a factory was used as the object to investigate the optimization and characteristics of Fenton oxidation coupled with coagulation pretreatment process.In this study, the CLT acid wastewater was firstly treated by Fenton oxidation and followd by coagulation. The main factors and the range of parameters of Fenton oxidation were determined by orthogonal test, and the effect of various factors on the treatment efficiency was determined by single factor experiments. Finally, the impact of various factors on the CLT acid wastewater COD removal efficiency was obtained, and the optimum value of each factor was determined.The parameters that affect the treatment efficiency in the Fenton oxidation experiment, such as H2O2and FeSO4·7H2O dosage and the molar ratio, pH and reaction time, and the parameters that affect the treatment efficiency in coagulation, such as type of coagulant, coagulant dosage, pH and reaction time, were investigated and determined in this studyThe optimum operating conditions of CLT acid wastewater treated by Fenton oxidation and coagulation pretreatment process were obtained. In the Fenton oxidation test:initial pH=3-4, the dosage of H2O2and FeSO4·7H2O were20mL/L and10g/L, the reaction time was30min. In the coagulation test:pH=9, the dosage of PAM was20mg/L, the reaction time was20min.The Fenton oxidation-coagulation combination experiment showed that the use of this method for the pretreatment of CLT acid wastewater is feasible. In the optimum operating parameters, the COD removal rate was higher than73.3%and the BOD5/COD can be elevated from0.07to0.34, making it suitable for subsequent biological treatment. In addition, the changes and charateristics of the raw wastewater and pretreated wastewater were analized by GC-MS and3D fluorescence spectroscopy.6benzene series materials can be detected in the raw wastewater by GC-MS. However, no featured organic pollutants can be detected when the wastewater was treated by Fenton oxidation. The three dimensional fluorescence spectrum analysis indicated the fluorescence peaks of CLT wastewater decreased obviously or even disappeared by the combination pretreatment process.