本科毕业设计说明书
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3000t/d制革废水处理工艺设计
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专 业 | 环保设备工程 |
班 级 | 环设141 |
学 号 | |
学生姓名 | |
指导教师 | |
完成日期 | 2018.5.24 |
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3000t/d制革废水处理工艺设计
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摘 要：本设计主要内容为制革废水处理工艺设计。众所周知，制革废水的水质成分复杂，含有大量的染料、油脂、硫化物、悬浮物、有机污染等，污染严重。设计内容有：设计水质水量为3000t/d；CODCr=1500~3000mg/L；BOD5=800~1200mg/L；SS=700~1000mg/L；pH值=6~9；色度200~400倍；氨氮=100~200mg/L；Cr3+≤1000mg/L；S2-=50~100mg/L。根据相关部门以及环境现状的要求，制革废水污水处理厂设计的出水水质应达到国家《污水综合排放标准》（GB8978-1996)一级标准及《制革及毛皮加工工业污水污染物排放标准》（GB30486-2013）行业标准中更为严格的标准，具体标准如下：CODCr=100mg/L；BOD5=30mg/L；SS=50mg/L；氨氮=15mg/L；S2-=1.0mg/L；pH值=6~9；Cr3+=1.5mg/L；色度30倍。
本次毕业设计对制革废水的处理进行了构筑物及主体处理工艺设计、处理设备的选型、厂区平面布置分析、工程经济分析等。首先预处理废水，将其除去铬离子后，进入粗细格栅筛滤后，经过辐流式沉淀池、曝气调节池、混凝沉淀池、氧化沟工艺、竖流式二沉池、污泥浓缩池等各类构筑物的层层处理后使出水水质完全达标后排出。主体工艺采用混凝沉淀+氧化沟工艺，对SS、CODCr、BOD5、色度等杂质的去除率较高，最终的处理出水水质均能达到国家一级标准及行业标准中较严格的标准。
对本次毕业设计经过较为详细的工程经济分析，估算出总投资量大约在651.5万元，处理废水成本为0.741元/吨，相比同类成本低廉，效果较优。
关键词：制革废水；污水处理；混凝沉淀；氧化沟
3000t/d tanning wastewater treatment process design
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Abstract: The main content of this design is the design of tannery wastewater treatment process. As we all know, the quality of tannery wastewater is complicated, and it contains a lot of dyes, grease, sulfides, suspended solids, organic pollution, etc. causing serious pollution. Design content includes: design water quality 3000t/d; CODCr= 1500~3000mg/L; BOD5=800~1200mg/L; SS=700~1000mg/L; pH=6~9; color 200~400 times; Ammonia ni -trogen=100~200mg/L; Cr3+≤1000mg/L; S2-=50~100mg/L. According to the requirements of the relevant departments and the current environmental conditions, the quality of the effluent designed by the tanning wastewater and sewage treatment plant shall comply with the national first-grade standard for Integrated Wastewater Discharge Standard (GB8978-1996) and the Sewage and Pollutant Emission Standard for Leather and Fur Addition Industry (GB30486-2013) stricter standards in the industry standards, specific standards are as follows: CODCr=100mg/L; BOD5=30mg/L; SS=70mg/L; Ammonia nitrogen=15mg/L; S2-=1.0mg/L; pH=6~9; Cr3+=1.5mg/L; color 50 times.
The graduation project designed the treatment of tannery wastewater, including the design of structures and main treatment processes, the selection of processing equipment, the layout analysis of the plant site, and the economic analysis of the project. First, the wastewater is pretreated, chromium ions are removed, and the coarse and fine grids are sieved and then subjected to radial flow sedimentation tanks, aerated conditioning tanks, coagulation sedimentation tanks, oxidation ditch processes, vertical secondary sedimenta -tion tanks, and sludges. The layers of the various structures such as the thickening pond are treated so that the quality of the effluent can be fully discharged and discharged. The main process adopts the coagulation and sedimentation + oxidation ditch process, which has a higher removal rate of impurities such as SS, CODCr, BOD5, and chroma. The final treated effluent water quality can meet the national first-class standards and the stricter standards in the industry standards.
After a detailed engineering economic analysis of this graduation project, it is estimated that the total investment is about 6.651 million yuan, and the cost of wastewater treatment is 0.741 yuan/ton, which is lower than the similar kind of cost and has a better effect.
Key words: Tannery wastewater；Sewage treatment；Coagulation precipitation；Oxidation ditch
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