【作者】 薛晓蓓；

【导师】 时文歆； 王志军；

【作者基本信息】 哈尔滨工业大学 ， 环境工程， 2011， 硕士

【摘要】 腐殖酸是天然水体中机污染物的主要成分,我国大部分地区的水源水在寒冷季节供给不足,并且水面冰封导致水体缺氧,水中动、植物残骸得不到及时降解从而导致腐殖酸污染加剧。腐殖酸的存在不仅导致水中色度升高,并且在胶体颗粒表面形成保护作用使水中杂质难以脱稳去除,进一步加大了低温低浊高色度水的处理难度。本文主要探讨如何利用廉价、安全、卫生的天然粘土—凹凸棒土作为吸附剂和助凝剂,联合常用混凝剂聚合氯化铝(PAC)处理低温低浊高色度水。处理低温低浊高色度水的关键问题之一是腐殖酸的去除,因此,首先做了凹凸棒土吸附水中腐殖酸的试验研究,并系统讨论其吸附动力学和热力学过程。试验结果表明,吸附平衡时间为70 min;15g/L凹凸棒土对5mg/L腐殖酸的去除率达到90%以上,并且随着腐殖酸初始浓度的增大,凹凸棒土吸附容量也随之增加;低温条件下,凹凸棒土吸附腐殖酸吸附等温线拟合相关系数由高度依次为,Redlich-Peterson>Freundlich>Langmuir>Temkin;凹凸棒土吸附不同初始浓度腐殖酸的动力学过程说明,Lagergre一级、Lagergre三级和Elovich吸附动力学模型均能较好的描述吸附过程。采用自来水配制水样Ⅰ模拟实际低温低浊高色度水,进行混凝静态试验结果表明,单独投加聚合氯化铝处理水样的最佳投量为35mg/L,此时出水水质不理想,投加助凝剂15mg/L凹凸棒土后,PAC的投量降低到9mg/L,最佳pH值为6～8,对色度、UV254、CODMn的去除率分别为81.25%、73.19%、44%,出水残余铝浓度和余浊分别为0.05mg/L和1.3NTU。为了更接近实际,采用松花江原水配制水样Ⅱ模拟低温低浊高色度原水。实验结果表面,凹凸棒土作为吸附剂和助凝剂投加到高密度沉淀池动态反应器中处理低温低浊高色度水,试验结果表明,高密度沉淀池的泥渣回流增加了低浊水的颗粒浓度,提高颗粒有效碰撞几率,加强反应器处理效果,更重要的是利用了沉淀池浓缩污泥剩余吸附能力。投加凹凸棒土后,高密度沉淀池的优势进一步得到体现,因为回流污泥中的凹凸棒土重新返回到混合池中,多次被循环利用,充分利用了有效资源;13.5mg/L聚合氯化铝+10mg/L凹凸棒土联合投加并回流污泥比为4.5%时,对水样Ⅱ处理效果较好,色度、UV254、CODMn的去除率分别为93.62%、76.83%、66.15%,出水浊度为1.5NTU以下,残余铝浓度0.061mg/L。更多还原

【Abstract】 Humic acid is the main components of natural organic pollutants in the natural water. Source water undersupplies in most of Chinese areas during cold season, and icebound season can lead to water body hypoxia, resulting in degradation of animals and plants wreck in time, thus make humic acid pollution intensifies. The existing of humic acid not only results in chroma increases but also forms protective effect on the surface of colloidal particle, which makes impurities in water sedimentate difficultly, and increases the difficulty of the treatment of low temperature, low turbidity and high chroma water.This paper mainly discusses how to use attapulgite as adsorbent and coagulant aid, and the objective is to treat low temperature, low turbidity and high chroma water combined with PAC.The removal of humic acid is one of key problems in the treatment of low temperature, low turbidity and high chroma water. Therefore, this paper first experimental study on adsorbing humic acid by using attapulgite as adsorbent, then it gives a systematic discussion about the adsorption kinetics and Thermodynamics behavior of attapulgite adsorb humic acid. The results show that the adsorption equilibrium time is about 70 min.The removal rate of humic acid can reach above 90% on the optimal conditions of 15g/L attapulgite adsorb 5mg/L humic acid. And the adsorption capacity of attapulgite increased with increasing the initial concentration of humic acid. The fitting correlation coefficient of adsorption isotherm of humic acid on attapulgite from high to low are respectively: Redlich-Peterson>Freundlich>Langmuir>Temkin. The data of adsorption kinetics experiments of different initial concentration of humic acid on attapulgite showed that Lagergre first order, Lagergre second order and Elovich dynamic adsorption model describe very well the adsorption process for humic acid on attapulgite.Overnight water was used to prepare water sampleⅠwhich simulate practical low temperature, low turbidity and high chroma water. The coagulation and sedimentation experiment results are as follows: the optium coagulant dosage is 35mg/L by auto-adding PAC alone, however, the effluent quality is non-ideal. The dosage of PAC decrease 9mg/L after auto-adding 15mg/L attapulgite, the removal rate of chroma, UV254 and CODMn is 81.25%, 73.19% and 44% respectively, the residual turbidity and residual aluminum content in the effluent is 0.05mg/L and 1.3NTU respectively.Songhua River Water was used to prepare water sampleⅡwhich simulate low temperature, low turbidity and high chroma water for the sake of closer to actual. Study on Experimental investigation of treating low temperature, low turbidity and high chroma by using attapulgite as adsorbent and coagulant aid to high dense settling pond reactor, The results are as follows: the return of sludge to high dense settling pond reactor not only increase the degree of low turbidity and the frequency of effective collision, strengthen the treatment effect of the high dense settling pond reactor, but also more importantly to make full use of thickened sludge in the sedimentation tank. Further strengthening the superiority of high dense settling pond reactor after auto-adding attapulgite, it is believed that the cause is mainly due to multiple cyclic utilization of attapulgite by returning mud waste to mixing pool, thus make full use of efficient resources. The removal rate of chroma, UV254 and CODMn is 93.62%, 76.83% and 66.15% respectively, the residual turbidity and residual aluminum content in the effluent is below 1.5NTU and 0.061mg/L respectively, and the effluent quality is ideal on condition of 10mg/L attapulgite, 12.5mg/L PAC and sludge return ratio 4.5%.更多还原