纤维素燃料乙醇废水水质分析及预处理技术

Quality analysis and pretreatment of cellulosic ethanol wastewater

摘要:

对中粮集团(COFCO)纤维素乙醇厂醪液废水进行了水质分析,废水中悬浮物含量达123868mg/L、CODCr为127667mg/L.利用GC-MS技术对废水中有机物成分进行了定性分析,检测出该废水中可定性的有机物52种,挥发酸中乙酸含量达29188mg/L.以固液分离的液体得率、CODCr去除率、处理速率、能耗等为指标,比较了自然沉降、离心分离、板框压滤3种物理预处理方法对该废水的处理效果.研究表明:板框压滤是一种较好醪液预处理方法,在0.6h/L的处理速率下,液体得率为66.44%、CODCr去除率为64.75%,耗能为0.22(kW·h)/L,大部分常规水质指标和离子浓度随着固液分离的进行均明显降低.

Abstract:

The quality of the wastewater from the equipment of COFCO’s cellulosic ethanol was analyzed and it was determined that the suspended solid was high to 123 868 mg/L,meanwhile CODCr was over 12 000 mg/L. At least 52 kinds of organic compounds were detected according to the GC-MS analysis and acetic acid as high as 29188 mg/L was found,which was dominated in the volatile fatty acids (VFAs) in the wastewater. Taking CODCr removal rate,liquid yield after pretreatment for SS removal,treatment rate and energy consumption per unit volume as evaluation parameters,three physical pretreatment methods for suspended solid removal was tested,including natural subsidence(NS),centrifugation separation(CS),plate and frame filter press method in laboratoryscale. Results show that the SS removal rate is 66. 44% for plate and frame filter-press filtration and COD removal rate can reach 64. 75% . The plate and frame filter press method is also predominant in the treatment rate (0. 6 h/L) and energy consumption per unit (0. 22(kW·h) /L). Most of the conventional water quality indicators and the ion concentration decrease significantly with the solid-liquid separation.