曝气+化学絮凝法预处理环氧丙烷废水

Pretreatment of epoxy propane wastewater by aeration chemical flocculation

根据环氧丙烷废水的特点,应用电化学法处理具有较高的可行性。运用电化学法处理PO废水前必须进行废水预处理,用以提高电流效率和延长极板寿命。采用曝气和化学絮凝结合的方法去除PO废水中的Ca2+,同时去除部分COD。对曝气、无机絮凝剂(PACl、PFS)和有机絮凝剂(PAM)对PO废水处理过程中的曝气量、曝气时间、投药量、复配和沉降时间等主要影响因子进行了实验研究,通过比较Ca2+、COD的去除效果、絮凝剂用量、沉降时间、处理成本等方面,在设定的实验参数下得到最佳预处理方案为:曝气量为2.5 L/min,曝气45 min,投加Na2CO3粉末24 kg/t废水,充分混匀后加入PFS+PAM复配絮凝剂。本方案具有废水处理效果好(Ca2+的去除率为77.03%,COD的去除率为37.46%)、投药量少((100+7.5)g/t废水)、沉降时间短(5 min)、处理成本低(0.675元/t废水)等优点。通过对比经预处理和不经预处理后电化学法对COD去除效果、电流和处理后阴极表面,验证了预处理方案的必要性与可行性。

According to the characteristics of epoxy propane wastewater, application electrochemical treat- ment was of high feasibility. Before using electrochemical treatment to dispose PO wastewater, pretreatment must be carried out to improve the current efficiency and prolong the plate life. In this study, a combination of aera- tion and chemical floceulation methods were used to remove Ca2＋ in the PO wastewater and COD was also partial- ly removed. Aeration, inorganic flocculants （ PACI, PFS） and organic flocculants （PAM） for PO wastewater treatment process aeration, aeration time, dosage, formulation and settling time were the main factors studied, via comparing the Ca2 ＋ and COD＇ s removal efficiency, floceulant dosage, settling time, processing costs,etc. , the optimum pretreatment regiman was obtained at the set test parameters： aeration rate was 2.5 L/min, aeration for 45 rain, adding amount of Na2CO3 powder was 24 kg/t, PFS ＋ PAM compound flocculant was added after mix well. The program had many advantages, for instance, high wastewater treatment effect （Ca2＋ removal rate of 77.03% ,COD removal rate of 37.46% ）, low dosage （ （ 100 ＋7.5） g/t） , short settling time （5 rain） , low pro- cessing costs （0. 675 yuan/t） and so on. By comparing COD removal effct, current and cathode surface after treatment between pretreated and non-pretreated electrochemical method, the necessity and feasibility of condi- tioning regimen were verified.