Study On The Treatment Process To Blending Waste Water Of MEK Production Installation

This watewater orignates from the blending waste water of MEK and MTBE device in certain factory of Jiangsu province .It has a character of high content of organic materials, complex ingredients and refractory biodegradability. All of the current literatures about MEK waste water are focusing on how to improve the MEK productivity, but not on how to treat the waste water of MEK Production Installation.The general technology and present development of the methods for high content organic waste-water treatment are reviewed in this paper. Through the analysis to this waste water,Considering the special character of the MEK waste water,the engineering feasibility and the requisite of low cost and high efficiency, this paper designs the following treatment technology:coagulation—tower's column air stripping —poor's air stripping—biological contact oxidation.PFS was adopted as coagulating agents by the experiment for the coagulating comparison .After preliminary treatment of air-stripping , the COD value of the MEK waste water decreases from 4000～5000mg/L to about 243mg/L.The followings are that the optimum experiment conditions are made out :at the step of tower's column air-stripping, the waste water flow 10L/H,air-to-liquid ratio 200,and pH value about 7,the COD value decreases from 4000～5000mg/L to about 1526mg/L;At the step of poor's air-stripping , air volume 2000L/H,air-stripping time 8 hours,the COD value decreases from 1526mg/L to 243mg/L.Afterwards, the waste water flow into the biological contact oxidation pool. At this step , the optimum experiment conditions is: temperature 25±1℃,pH value 6.7～7.4,the dissolved oxygen concentration 2～4mg/L,the Nitrogen phosphor supplement ratio C:N:P=150:5:1 and the HRT 4 hours ,the assembled fillers adopted. After the biological contact oxidation process, the average COD value decreases to less 100mg/L, thus the outcome water reaches the standard stipulated in the national regulation GB8978-2000. The dynamic model of the MEK waste water biological contact oxidation treatment step is also studied, its dynamic equation approximately conform to theMonod equation and its dynamic equation is＝0.00703＋2.0008.At the experiment temperature 25±1℃,the dynamic invariable Ks＝0.00351mg·L-1;k＝0.4998 mg·L-1·H-1...