Experimental Study On Dibutyl Phthalate Wastewater Pretreatment

Phthalie acid esters plasticizer is a kind of typical persistent organic pollutants and widely used in plastic products, coatings and other production areas. It is easy to accumulate in the living environment after entering the environment and lead to the biological mutation. Therefore, it produces the environment and human health hazards.The main pollutants of the plasticizer wastewater is phthalate ester butyl.The wastewater quality was as follows:CODcr=65000mg/L, PH=9-10, temperature≤90℃.With microbial toxicity, it is recalcitrant organic matter for microorganisms. According to the wastewater charactistics,this paper studied the decomposing effect of the plasticizer wastewater by micro electrolysis, Fenton oxidation and high temperature hydrolysis:1)The optimal reaction conditions of micro-electrolysis treating plasticizing agent wastewater as follows:pH of 4, iron carbon ratio of 1:2, residence time of 4 h. Then, COD removal rate was 34.9%, dibutyl phthalate removal rate of nearly 99%.2) The optimal reaction conditions of Fenton treating plasticizing agent wastewater as follows:pH of 3.5, FeSO4/H2O2 ratio of 5:1,reaction time of 2.5 h. Then, COD removal rate was 68.3%,dibutyl phthalate removal rate of 92%.3) The optimal reaction conditions of high temperature hydrolysis treating plasticizing agent wastewater as follows:pH of 11.5,reaction time of 4 h, reaction temperature of 95℃.Then, COD removal rate was 46.57% and dibutyl phthalate removal rate reached 99%.Three pretreatment methods can efficiently degrade phthalic acid dibutyl, but considering practical engineering problems and engineering feasibility, high temperature hydrolysis method was more fit for engineering practice pretreatment.