【作者】 周亮；

【导师】 谢光炎；

【作者基本信息】 广东工业大学 ， 环境工程， 2012， 硕士

【摘要】 造纸废水循环回用可以减少废水排放,降低吨纸耗水量。但是废水循环过程中积累的有害物质又会影响生产过程和产品质量。本课题以佛山某鞋材纸板厂因废水循环导致的问题为研究对象,分析了这些问题产生的原因,提出了解决这些问题的几点建议,选择用适当的方法对造纸废水进行适当处理并将其回用于生产中。本研究的主要目的是为该鞋材纸板厂在废水循环回用过程中出现的问题提供解决方案,同时也为其它纸厂的废水回用提供一定的参考。本文跟踪分析白水循环的水质变化情况,发现了有害物质积累随废水循环的变化规律。结合废水循环回用时的生产情况,分析出了对生产有影响时的循环废水水质指标的临界值：COD为5700mg/1左右,SS为1100mg/1左右,色度为60,此时循环进行了6天。而当循环进行13天左右的时候,网下白水的COD、SS等达到动态平衡,其平衡值分别为：COD为15700mg/1,SS为5600mg/1,色度为120。为了消除有害物质积累带来的影响,工人增加了生产助剂的投加量,但当循环进行到一定程度时,助剂投加量的增加都不能消除有害物质对生产的影响,此时工人排放部分废水,引入清水,生产废水又进入下一个循环回用周期。综合考虑工艺的简单适用性和初投资的经济性,本课题选择混凝沉淀和化学氧化作为该厂废水的处理工艺。研究考察了混凝剂的投加量、pH对混凝沉淀效果的影响；对于化学氧化试验,则考察了氧化剂的种类、氧化剂的投加量、pH以及反应时间对其处理效果的影响。试验结果显示：(1)混凝沉淀的最佳运行条件为：PAC投加量为120mg/1,PAM投加量为2.5mg/1,pH值为9。在此条件下,废水的SS去除率约为70%,COD去除率约为30%,而脱色率为48.35%。(2)三种化学氧化试验中,Fenton氧化的最佳运行条件为：H2O2投加量为40ml/L约为理论投加量的1.3倍,nFe2+/nH2O2的比值为0.1,pH值为4,反应时间为80min,在此条件下,废水的COD下降72.5%,色度下降42.9%；NaClO氧化的最佳运行条件为：NaCl0投量为10ml/l,pH值为3,氧化时间为45min,此条件下,废水的COD的去除率为27%,脱色率为75.4%；KMnO4氧化的最佳运行条件为：KMnO4投量为40mg/l,pH值为3,氧化时间为50min,它的脱色效果很不明显,对COD的去除率为24.56%。(3)混凝沉淀和化学氧化的联合处理试验表明,混凝沉淀-Fenton氧化工艺可较好的降低废水的COD,对其去除率可达74%以上,处理后的废水可达到回用要求,而NaClO氧化-混凝沉淀工艺则对废水的脱色效果较好,它对废水的脱色率达到81%以上。因此,在一般情况下,可用混凝沉淀-Fenton氧化联合工艺处理生产废水；当对回用水的脱色效果要求较高时,则可用NaClO氧化-混凝沉淀工艺处理废水。更多还原

【Abstract】 Wastewater reusing can reduce the wastewater discharge and lower water consumption of paper making. A shoe paperboard plant of Foshan had some problems because of waste water recycling. This topic analyzed the causes of these problems, put forward several countermeasures to solve these problems, and chose appropriate methods to treat this wastewater properly then reused it. The main purpose of this study was not only to provide a solutions for these problems that wastewater reusing leads to in the shoe paperboard plant,but also to provide some reference for wastewater reuseing of other paper mills at the same time.This paper analyzed the water quality changes of whitewater,and found the variation of the accumulation of harmful substances in cycle.Combined with the production situation as wastewater recycling, it provided critical value of the circulating water index:COD was about5700mg/l;SSwas about1100mg/l; the chroma was60times,and the wastewater had be reused for6days. When the wastewater had be reused for13days or so, COD and SS of whitewater in wet end reached a dynamic balance,then the COD was15700mg/l or so,SS was5600mg/l or so,and the chroma was120times or so.In order to eliminate the effects of harmful substances that were accumulated by wastewater cycle, workers had to increase production additives dosage.However, when the cycle was to a certain extent,additives that were increased cound not eliminate the harmful influence on production. The workers had to discharge wastewater and inject fresh water,then wastewater enter into the next reuse cycle.Considering the simple and applicability of the process and the efficiency of the initial investment,this paper chose coagulation precipitate and chemical oxidation as the wastewater treatment process. It investigated the effect of the amount of coagulant dosage and pH on coagulation precipitation. As for chemical oxidation experiment,it investigated the effect of the oxidant species, oxidant dosage, pH and reaction time on its treatment effect. The results showed that:(1) The best operating conditions of coagulation sedimentation were that PAC dosage was120mg/L, PAM dosage was2.5mg/L and pH was9.Under these conditions,the removal of SS was about70%, COD reduced about30%and the removal of chroma was48.35%.(2) The best operating conditions of Fenton oxidation were that H2O2dosage was40ml/L, which was about1.3times of theory dosing quantity, the ratio of the nFe2+/nH2O2was0.1, pH was4and the reaction time was80minute, under these conditions, COD of wastewater reduced about30%and the removal of chroma was42.9%. The best operating conditions of NaClO oxidation were that NaClO dosage was10ml/L, pH was3, oxidation time was45minute, under these conditions,removal of COD was27%and the chroma reduced75.4%. The optimum operating conditions of the KMnO4oxidation were that KMnO4dosage was40mg/l, pH was3, oxidation time was50minute.In KMnO4oxidation experiment, The decolorization effect was not obvious,and the best removal of COD was24.56%.(3) The joint experiment of Coagulation precipitate and chemical oxidation showed that the coagulation precipitate-Fenton oxidation process cound be effectively reduced the COD of wastewater,the removal of COD was above74%, the treated wastewater cound reach the level for reusing.And the decolorization effect of NaClO oxidation coagulation sedimentation process was better than other processes, and it cound reduce chroma of wastewater more than81%. In general, the coagulation precipitate-Fenton oxidation process cound be used for wastewater treating.However, NaCIO oxidation-coagulation sedimentation process should be used when decolorization is needed.更多还原