化工厂区雨排水回用循环水补水及时研究.pdf

天津大学
硕士学位论文
化工厂区雨排水回用循环水补水及时研究
姓名:何琳
申请学位级别:硕士
专业:化学工程
指导教师:夏淑倩;刘发强
20090107
摘要
本文以某化工厂区雨排废水(主要由生产车间的机泵冷却水、地面冲洗水、
低温水回水、设备管道导淋水以及厂区雨排水组成)为研究对象,探索将其回
用为循环水补水的工艺路线、操作参数,并在此基础上考察本实验主要处理单
元固定床生物膜反应器的工艺稳定性、抗污染冲击以及抗油污染冲击的能力。
通过采用以生物膜为主要处理单元,膜分离、混凝一絮凝、砂潓等为辅助处
理单元的六种工艺路线探索试验,确定了将该股废水回用为循环水补水比较经
济、实用的工艺路线是生物膜+砂滤组合工艺。生物膜处理单元采用固定床生物
膜反应器,该反应器利用了A/O(缺氧/好氧)工艺,并且对常规的A/O工艺进
行了改进,其中A段利用了固定颗粒物质作为微生物的载体,在O段利用了半
软性组合填料作为生物载体,在缺氧段的兼性厌氧菌的作用下,有机物发生水
解酸化作用,提高废水的可生化性;在O段利用填料上所附生物膜中微生物氧
化分解作用、填料及生物膜的吸附阻留作用和沿水流向下形成的食物链分级捕
食去除作用以及生物膜内部的反硝化作用,保证了出水的稳定性和抗冲击能力。
实验结果表明,半软性组合填料挂膜速度快、生物量大,处理效果优于多
孔旋转球型悬浮填料;固定床生物膜反应器处理该化工厂区雨排废水的最住操
作参数为水力停留时间1h,气水比为0.5:1,在最佳操作参数下处理该股废水,
COD、BOD、NHxN去除率分别达70%、80%、65%以上;30天的稳定运行试
验表明固定床生物膜反应器稳定性能良好,COD、BOD、NH3-N、浊度平均去
除率分别为7237%、79.85%、75.57%、75.0%,出水COD在20mgL左右,BOD
均在5mgL以下,NH-N均在3.5mgL以下、浊度在5NTU以下;固定床生物膜
反应器出水再经过砂滤处理,水质进一步提高,完全可以回用为循环水补水。
另外,抗有机污染冲击试验和油污染冲击试验表明,固定床生物膜反应器的抗
冲击性能强,冲击后调整进水水质,恢复运行10天左右,生物膜逐渐恢复,去
除效果、出水水质恢复到冲击前的水平。同时,固定床生物膜反应器集厌氧生
物滤床与好氧生物膜于一体,具有良好的硝化反硝化功能。
该技术每年可节约新鲜水约100×10吨,年节约资金可达约205万元,经
济效益、环境效益、社会效益显著,具有很好的应用前景。
关键词:化工厂区雨排水;循环水补水;生物膜;固定床生物膜反应器;AO
ABSTRACTT
The present study was focused on chemical plant sewage(mainly composed by
pump cooling water, ground flushing water, low temperature backwater, equipment
drip water and plant drainage rain water ) The process and operation parameters of
recycling chemical plant sewage for makeup water of circulation were studied. On
the basis of the above investigations, process stability, anti-pollution and anti-oil
pollution power of fixed bed reactor of biomembrance were studied
In the study, biomembrance was employed as the main processing unit and
membrance separation technique, coagulate-flocculation, sand filtration and et al. as
auxilary processing units. And then six ways of recycling chemical plant sewage for
makeup water of circulation were studied comparatively. It was found that the most
ecnomical and practical way is the combination of biomembrance and sand filtration.
Fixed bed reactor of biomembrance with improved A/O process was used. In
anaerobic(A)part, fixed particles was used for microbe carrier and in oxygen(O)part
semi-soft filler was used for microbe carrier. In anaerobic part, under the action of
anaerobic bacteria, organic materials were hydrolyticly acdified by which
biochemical performance of chemical plant sewage was improved greatly. In oxygen
oart, under the composite impacts of microbe oxygenolysis on biomembrance carrier,
adsorption blocking of filler and biomembrance, graded predation along with water
flow direction in food chain and denitrification in biomembrance, the stability
and impact properties of outlet water were preserved
Experiments results indicated that when using semi-soft filler, biomembrance
culture rate and microbe quantity were increased; the as-treated effect was more
desirable than that of porous rotary suspended filler. The optimal operation
parameters of recycling chemical plant sewage using fixed bed reactor of
biomembrance was: hydraulic residence time was 1 h, gas-to-water ratio is 0.5
Under this optimal condition, the removal ratios of COD(chemical oxygen
demand), B OD(biochemical oxy en demand )and ammonia n