强化混凝技术在集中式印染废水处理厂的应用研究

发布时间：2018-03-30 17:42

  本文选题：集中式印染废水　切入点：强化混凝　出处：《东华大学》2017年硕士论文

【摘要】：印染废水被认为是最难处理的工业废水之一,因为其中含有大量难降解的有机物、而且具有色度深、成分复杂、水质变化大的特点。目前国内外对印染水的处理方法很多,但在实际工程应用中,无论是在纳管处理阶段还是达标处理阶段,混凝法由于其成本低、经济性高,可操作性强而被大多数印染厂广泛使用。随着近年来印染行业污水排放标准不断提高,而且印染废水中的溶解性有机物种类繁多、组分复杂,包括难降解有机物、有机物降解中间产物以及溶解性微生物产物等。因此对印染废水中的残余溶解性有机物的有效控制势在必行。而常规混凝关注的只是水中的颗粒性物质和胶体的去除效果,为了去除水中溶解性有机物以达到控制消毒副产物的目的,美国环保总局(USEPA)推荐了强化混凝作为最佳可行技术。所谓强化混凝,就是以去除常规处理中的剩余溶解性有机物为目的,再通过调整p H值或加大混凝剂的投加量的方法,来加强混凝效果,尽可能地去除水中消毒副产物的前体物(DBPFP)。本研究采用Al_2(SO_4)_3、PFS、Fe Cl_3、、PAC、Fe SO4、Mg SO4 6种有代表性的混凝剂,对集中式印染废水处理厂无锡市某污水处理厂调节池出水进行强化混凝处理,探讨废水中溶解性有机物在强化混凝处理过程中转化规律及各种混凝剂对印染废水中溶解性有机物处理的有效性。得到以下主要结论:(1)原水分子量主要集中在100k Da和1k Da两个分子量区间内。该污水处理厂调节池出水中:COD_(cr)、UV254在100k Da分子量区间中所占比例分别为55.29%、36.48%;在1k Da分子量区间内,比例为24.66%、23.92%。强化混凝处理之后,大分子有机物去除效果明显,小分子有机物在水中比例剧增。同时,根据混凝出水后的SUVA值可以表明,强化混凝可以达到去除该废水中亲水性物质的目的。(2)对于COD_(cr)指标而言,在100k Da和1k Da的分子量区间内,最有效的混凝剂为FeCl_3;在30-100k Da、10-30k Da和3-10k Da的分子量区间内,最有效的混凝剂为Al2(SO4)3。对于UV254指标而言,在100k Da的分子量区间,Fe SO4和PFS显示出了最佳效果;对于30-100k Da分子量区间,Al_2(SO_4)_3效果最佳;PFS混凝对分子量区间在10-30k Da和1-3k Da内的有机物去除效果最佳;在3-10k Da和1k Da分子量区间内,Fe Cl_3显示出了最好的去除效果。(3)原水中憎水中性物(Ho N)和亲水性物质(HiM)占了绝大部分,分别达到54.89%、27.36%。而强化混凝的确对改善水中亲疏水性有机物的比例有效果,对HoN来说,FeCl_3的COD_(cr)去除率达到73.6%;对于Ho A来说,Al_2(SO_4)_3对COD_(cr)去除率可达到98.52%。对于WHo A和Hi M两种组分,PAC都显现出了最佳去除效果。(4)原水中溶解性有机物分子上的官能团主要是苯环、羟基、酚、醚、酮、酯基以及胺基等。通过红外光谱分析和GC-MS谱图分析结果可知:PFS对羟基混凝去除特性好于其他3种絮凝剂;PAC对含苯环的有机物去除效果较差;铁盐对酯类C-O有更好的去除特性。(5)通过单质混凝剂的强化混凝实验结果分析,选定Al_2(SO_4)_3和PFS复配的方案,并且通过强化混凝实验确定最佳配比为:Al2(SO4)3 30%、PFS 70%。(6)通过红外光谱结果分析,复配混凝剂对酯、醚、酚、醇类化合物中的C-O伸缩振动峰有相较于Al2(SO4)3和PFS单独使用时更好的去除特性。
[Abstract]:Printing and dyeing wastewater is one of the most difficult industrial wastewater treatment, because it contains a lot of organic matter degradation, but also has deep color, complex composition, characteristics of large changes in water quality. At present many processing methods of printing and dyeing water at home and abroad, but in practical engineering applications, both the processing stage in nano tube or standard the processing stage, the coagulation method because of its low cost, high economical efficiency, strong operability and is widely used in printing and dyeing factory. In recent years, with the majority of wastewater discharge standards of printing and dyeing industry continues to improve, and dissolved organic species in dyeing wastewater is various, complex components, including refractory organic compounds, organic intermediate the product and soluble microbial products. So the effective control of the residual dissolved in dyeing wastewater of organic and conventional coagulation. It is imperative to focus only on water particles and colloids to In addition, in order to remove the dissolved organic matter in water in order to control the disinfection by-products, the United States Environmental Protection Agency (USEPA) recommended enhanced coagulation as the best viable technology. The enhanced coagulation is to remove residual dissolved organic matter in conventional processing for the purpose, and by adjusting the p value of H or increase method the dosage of coagulant, to enhance coagulation effect, as far as possible the removal of precursors of disinfection by-products (DBPFP). This study uses the Al_2 (SO_4) _3, PFS, Fe, Cl_3, PAC, Fe, SO4, Mg, SO4 6 kinds of coagulant for centralized treatment printing and dyeing wastewater treatment plant in Wuxi city sewage treatment plant water enhanced coagulation treatment of wastewater of dissolved organic matter in a variety of rules and transformation in enhanced coagulation process of coagulant on effectiveness of dissolved organic matter in the dyeing wastewater treatment. The main conclusions are as follows: (1) The molecular weight of raw water mainly concentrated in 100k Da and 1K Da two molecular weight range. The sewage treatment plant effluent pond: COD_ (CR), UV254 100k Da for molecular weight range were 55.29% and 36.48%; in the 1K Da molecular weight range, the ratio was 24.66%, after 23.92%. chemical coagulation treatment, organic matter removal effect, small organic molecules increase in water ratio. At the same time, according to the SUVA value of the effluent of coagulation can show that enhanced coagulation can effectively remove hydrophilic substances in the wastewater. The objective (2) to COD_ (CR) index, in molecular 100k Da and 1K Da content range, the most effective coagulant is FeCl_3; in 30-100k Da, 10-30k Da and 3-10k molecular weight range of Da, the most effective coagulant is Al2 (SO4) for the UV254 3. index, in the range of molecular 100k Da, Fe SO4 and PFS show the best results for 30-100k; Da鍒嗗瓙閲忓尯闂，

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