设计总说明:本课题作为高校环境工程专业本科生毕业设计项目,旨在为某造纸企业设计合理的废水处理生化工艺以及整个废水处理厂区的规划设计。根据设计任务要求,进水化学需氧量为3000mg/L、生化需氧量500mg/L、悬浮物SS=700mg/L;要求出水化学需氧量小于400mg/L、生化需氧量小于30mg/L、悬浮物小于150mg/L。设计综合比较了几种在造纸废水处理上常用的几种工艺,并最终确定了絮凝沉淀—水解酸化—接触氧化的物化+生化工艺,初步预计出水可完全达标。本设计同时参考了浙江嘉兴大洋纸业有限公司废水处理车间的工艺和大量的文献资料,与上述企业的一线工人进行了一定的沟通。10065
造纸废水是工业废水中比较难处理的一类废水。制浆造纸工业废水中需氧物质、合成有机物、有机卤化物、悬浮物和植物营养物等都是容易对环境造成危害的主要污染物。造纸废水中一部分是制浆过程产生的浓废水,其污染负荷占总污染负荷的80%-90%;另一部分是抄纸水,其浓度相对较低,污染较轻。造纸废水的特点是悬浮物含量高,颗粒较大的悬浮物主要是纸浆微纤文,可通过斜网过滤等物理法去除,而细小的悬浮物主要为木质素、糖类等降解产物或衍生物及有机化学助剂等,其携带的COD较大颗粒悬浮物要多得多,一般的物理方法难以去除。
进水通过粗格栅去除较大的漂浮物,通过提升泵提升至调节池,其中调节池与细格栅合建,细格栅在调节池前,细格栅起到进一步去除漂浮物的目的,而调节池则用于均化进水水质,为后续生物处理提供稳定的进水。调节池出水再进入澄清池,加混凝剂去除COD和SS,并提高一定的B/C比,提高可生化性能。物化处理后进行生化处理,首先是水解酸化,该工艺主要用于提高废水的可生化性,原理主要是厌氧微生物将难降解的大分子有机物分解为容易生物降解的小分子有机物。通过水解酸化处理后,再利用生物接触氧化,进一步的去除COD和BOD,出水经过二沉池固液分离,出水径清水池澄清后排出,剩余污泥与絮凝沉淀污泥一道经浓缩池浓缩后外运,回流污泥回流至水解酸化池,浓缩池滤液回流到调节池循环。
本次设计严格遵循国家相关法规、规范和标准, 确保各项处理水质指标达到相应的国家排放标准,参考了给水排水设计手册等多部文献资料;废水处理装置布置紧凑、流畅,尽量减少占地面积,坚持实用和美观相结合的总布原则,选择工艺简单;采用目前国内成熟、实用的处理工艺;尽量通过优化设计降低工程投资及运转费用,努力实现技术先进与企业财力相适应。
关键词:设计;造纸废水;生物接触氧化;生化工艺
Instructions:
As undergraduate thesis program for college students whose major is environmental engineering ,the subject is supposed to design proper biochemical treatment process and the whole factory field for certain papermaking corporate. According to the requirements from design task, as to inlet raw water ,the chemical oxygen demand is 3000mg/L,biochemical oxygen demand is 500mg/L, the concentration of suspended solid is 700mg/L;as to outlet water, the chemical oxygen demand is 400mg/L,biochemical oxygen demand is 30mg/L, the concentration of suspended solid is 150mg/L. The design is based on several general processes and finally we confirm the treatment method by coagulation and sedimentation—hydrolytic acidification—bio-contact oxidation. It’s estimated that outlet water can catch the standard.Meanwhile, I also refered to the process of Dayang Paper Limited Corporate,Jiaxing,Zhejiang province and other literatures. There are some professional communication between me and workers from Dayang.
The papaermaking wastewater is kind of hard to treat among wastewater from industries.Oxygen Demand material ,synthetic organic compounds,organic halides,suspended matter and plant nutrients in wastewater from pulp and paper industry are likely to cause harm to the environment.One part of wastewater is of high concentration.the pollution load occupy 80-90 percent of the total pollution load;the other is papermaking water,its concentration is relatively low and holds less pollution.Papermaking wastewater is characterized by high levels of suspended solids,the particles are mainly large micro-fiber pulp,physical removal can be filtered through the slant network,small suspended solids are mainly degradation products, such as lignin and sugar or derivatives and organic additives .It carries a lot particles suspended solid , general physical methods is difficult to remove them. 10000立方米每天采用生化工艺处理造纸废水的优化设计+CAD图纸:http://www.youerw.com/huaxue/lunwen_8979.html