沼液预处理最优混凝搅拌条件的研究

通过混凝法对沼液进行预处理最优条件的研究,为沼液预处理提供参考。在实验室条件下,对COD、TN、TP、色度和SS的去除率综合评价混凝工艺效果。实验中依次进行混凝剂投加量、助凝剂投加量、pH和搅拌强度的单因素实验,进而通过正交实验确定沼液预处理最优的混凝搅拌条件。试验结果表明:PAC投加量为4 g/L、PAM投加量为50 mg/L、搅拌速度为200 r/min、混凝阶段同时投加PAC和PAM,处理后的水样COD、TN、TP、色度和SS分别为216.20、181.99、0.18、11.77和71.67 mg/L,去除率分别达到92.51%、88.85%、99.75%、98.37%和89.46%,达到畜禽养殖业污染物排放标准(GB18596-2001),减轻了后续污水处理的负荷,为沼液实际处理提供了理论支持。

Study on optimal condition of coagulation and agitation in pretreatment of biogas slurry

The optimal condition of pretreatment of biogas slurry by coagulation was researched in order to provide reference for the pretreatment of biogas slurry. The effects of coagulant tcchnique were evaluated according to the removal of COD, TN, TP, color and SS under laboratory conditions. The optimum technological conditions were determined based on the single factor and orthogonal experiments. The results showed that in the conditions of which dosage of PAC is 4 g/L, dosage of PAM is 50 mg/L,stirring speed is 200 r/min,while PAC and PAM are added in stage of coagulation, the contents of COD, TN, TP, color and SS were decreased to 216.20, 181.99, 0.18, 11.77 and 71.67 mg/L respectively, the removal rate of COD, TN, TP, color and SS were reached to 92.51%, 88.85%, 99.75%, 98.37% and 89.46% respectively,which could completely meet the discharge standard of pollutants for livestock and poultry breeding(GB18596-2001),which can reduce the load of subsequent wastewater treatment and provide theoretical support for the practical treatment of biogas slurry.