【作者】 李丽娟；

【导师】 范迪；

【作者基本信息】 青岛理工大学 ， 市政工程， 2009， 硕士

【摘要】 造纸行业的水污染问题一直是社会关注的焦点,也是污水防治领域的热点问题。造纸工业是一个耗水大户,排放的废水量很大,对环境的污染也相当严重。随着环保力度的进一步加大和水资源的短缺,排放标准必将更为严格,对造纸中段废水进行深度处理并使其达到回用标准将是造纸企业面临的重要课题。山东省是缺水的省份,山东省的造纸工业环境保护,特别是废水处理工作,政府重视,企业投入大,设施运行好,一直走在行业前列。此课题正是在这样的背景下由山东省环保局立题,来自课题造纸废水处理,是其中的一部分。本文以某造纸厂二级生化处理的中段废水出水为研究水样,探讨了化学混凝技术深度处理造纸中段废水的技术问题,为造纸中段废水的回用打下一定基础。本文通过化学混凝技术,利用不同化学混凝剂对造纸二级生化处理中段废水出水进行深度处理,并研究了试剂种类及用量、pH值、反应时间、沉淀时间等因素对处理效果的影响,对比分析了反应前后废水的化学需氧量COD_cr、色度的去除率,总结出最佳处理工艺条件。本文主要研究了混凝剂PAC、PFS以及Fenton试剂在深度处理造纸中段废水中的应用。实验研究结果表明:PAC与PFS深度处理此造纸中段废水,在pH值为7⁸时,混凝剂PAC与PFS按2:1的比例配合、加药量400mg/L、助凝剂PAM加入量1mg/L、搅拌速度70n/min、搅拌时间10min、混凝后沉淀30min,为最佳处理工艺条件,COD_cr可降到90mg/L以下,COD_cr可去除率达70%以上;色度可降到90倍,色度去除率可达82%。正交实验考虑混凝剂种类、投加量、反应时间、助凝剂四个因子对COD_cr和色度的去除率的影响是一致的,主次顺序依次是混凝剂种类→投加量→反应时间→助凝剂。Fenton试剂深度处理此造纸中段废水,当pH值调为3、投药量Fe²⁺1mmol/L、H₂O₂4mmol/L、混凝反应时间为40min、沉淀时间为30min时,为最优组合,去除效果最佳。COD_cr可降低到45mg/L,去除率可达到85%;色度可降到50倍,去除率可达到90%。正交实验所考虑Fe²⁺的投加量、H₂O₂投加量、pH值、反应时间四个因素,由实验结果进行分析得出,对COD_cr和色度去除率的影响主次顺序不完全相同。对COD_cr的去除率影响由大到小依次为Fe²⁺的投加量→H₂O₂投加量→pH值→反应时间。对色度的去除率影响由大到小依次是H₂O₂投加量→pH值→Fe²⁺的投加量→反应时间。更多还原

【Abstract】 Waste water pollution of paper-making industry has been the focus of attention in the field of prevention and treatment of waste-water discharge.Consumption Paper industry need consume a big amount of water,and meanwhile the number of sewage disposal is very large.Environmental pollution is quite serious.With the increase of environmental protection efforts and the shortage of water resources,sewage discharge standard will be more strict.The enterprises will be faced to an important subject that advanced treatment of the papermaking middle-stage wastewater and up to reused standard.The area of Shandong province is lack of water.The paper industry’s environmental protection in Shandong Province,particularly the treatment of waste water,has been at the forefront of the industry.Government and corporate pay much attention to environmental pollution,and the facility is operating well.This title is set up by the Shandong Environmental Protection Agency in this context,which is a part of the subject of paper-making waste water treatment.This article studys advanced treatment of the papermaking middle-stage wastewater with coagulation technology and lay the foundation for wastewater reuse.In this paper,chemical coagulation technology was used to treat papermaking middle-stage wastewater with different coagulant and studied the amount of reagent, pH,reaction time,the precipitation time on the degradation effect,It made a comparative study on wastewater’s chemical oxygen demand CODcr and the color removal before and after coagulation and summed up the best process conditions.This paper was focused on advanced treatment of the papermaking middle-stage wastewater with coagulation PAC,PFS,as well as Fenton reagents,analysing effect factor containing coagulation dosage,pH,reaction time,deposition time and the removing rates of COD_cr and colour after coagulation,summed up the best conditions. Experimental results showed that under the conditions of value of pH 7.0～8.0, PAC/PFS ratio 2,coagulation dosage 400 mg/L,PAM addition of 1mg/L,mixing speed 70n/min,stirring time 10 mins,deposition time 30 mins,for the best conditions,and COD_cr down to 90mg/L below,the removal efficiencies of COD_cr were more than 70%, and the color down to 90 times,the color removal rate above 82%.The result was most efective.The four factors of CODcr and color removal in orthogonal is the same of the impact of the order of priorities,and followed by descending coagulant type→dosage→reaction time→the flocculant.For Fenton reagents,when pH adjusted to 3,Fe²⁺dosage 1 mmol/L and H₂O₂ 4mmol/L,the reaction time 40min,deposition time 30min,was the optimal level for the portfolio and has the best removal efficiency.The COD_cr reduced to 45mg/L and the removal rate was 85%,the color down to 50 times and the removal rate was 90%. The four factors of CODcr and color removal in orthogonal is not the same of the impact of the order of priorities,The results orthogonal analysis affected COD_cr of primary and secondary followed by descending order of Fe²⁺dosage→H₂O₂ dosage→pH→reaction time,but for color removal is H₂O₂ dosage→pH→Fe²⁺ dosage→reaction time.更多还原