复合絮凝剂处理卡拉胶废水的研究

发布时间：2018-03-12 09:11

本文选题：卡拉胶压榨水　切入点：絮凝剂　出处：《上海应用技术学院》2015年硕士论文　论文类型：学位论文

【摘要】：本论文根据卡拉胶废水(卡拉胶压榨水和第一次水洗液)现状及卡拉胶废水的来源和特点,针对卡拉胶行业面临的严峻形势和挑战,了解工业废水常用的处理技术。在此基础上,研究了化学絮凝法对卡拉胶压榨水和第一次水洗液的处理。从企业要求出发,选择简单可行的方法对压榨水和第一次水洗液进行处理研究,以期处理后的压榨水可回用,第一次水洗液的出水水质得到提高。本论文得出以下研究内容及结果：(1)对卡拉胶压榨水的絮凝处理：采用聚合氯化铝(PAC)作絮凝剂,考察絮凝剂添加量、温度、pH、沉降时间对絮凝效果的影响；聚丙烯酰胺(PAM)作助凝剂与PAC复合使用,考察PAM、PAC添加量、温度、pH对絮凝效果的影响。结果表明,PAC/PAM复合絮凝剂的使用可有效降低小分子卡拉胶的含量,提高絮凝效率,PAC添加量及水样pH对处理效果影响较明显。实验以卡拉胶的去除率和Al3+的残留量为指标,确定了絮凝剂处理压榨水的较佳试验工艺。结果显示,PAC/PAM复合絮凝剂对卡拉胶压榨水的处理效果普遍优于PAC; PAC、PAM用量分别为2g/L、15mg/L, pH 5-8,温度25-35℃,沉降时间30min,在上述条件下,小分子卡拉胶的去除率达到90.0%以上,Al3+残留量小于0.2mg/L,水样色泽接近蒸馏水,可回用于卡拉胶生产其他用水工段。(2)由于第一次水洗液水质较复杂,高碱度、高色度、高COD、高氯等特点,使得第一次水洗液处理难度较大。实验选用聚合氯化铝(PAC)、聚合硫酸铝铁(PAFS)、聚合硫酸铁(PFS)、AlCl3及壳聚糖(CTS)作为絮凝剂对废水进行处理,实验确定PAC、PFS、CTS三种作为絮凝剂；选择四种不同类型聚丙烯酰胺(PAM)作助凝剂,结果显示,分子量800万的阴离子型聚丙烯酰胺效果较好。实验过程中,由于第一次水洗液碱度很大,需经过酸中和,然后进行实验。实验以COD和色度去除率为指标,考察絮凝剂的种类、用量,助凝剂种类、用量及pH对絮凝效果的影响。结果显示,混凝剂对第一次水洗液处理效果普遍优于絮凝反应。从实验结果也可得出,对于COD及色度较高的第一次水洗液絮凝的处理其添加量：PAC添加量为3.50g/L, PFS添加量为5.25g/L, PAM添加量为0.15g/L,待处理水样pH为4-5左右,对COD及色度去除效果最佳,即COD去除率为73.70%,色度去除率为72.80%左右；对于高COD低色度的第一次水洗液而言,采用复合絮凝剂CTS/PAC/PAM对其处理效果最佳,在CTS添加量为0.10g/L, PAC添加量为3.50g/L, PAM添加量为0.20g/L,待处理水样pH调节至7左右的条件下,该絮复合凝剂对第一次水洗液的处理效果最佳。在次条件下,COD去除率为54.20%左右,色度去除率为73.50%。综上所述,PAC/PAM复合絮凝剂处理卡拉胶压榨水,得到较好的处理效果,基本满足企业要求。选择合适的絮凝剂处理第一次水洗液得到较好的效果,提高出水水质。
[Abstract]:This paper is based on the carrageenan wastewater (carrageenan squeezed water and first wash water) source and characteristics of the status quo and carrageenan wastewater, in view of the severe situation and challenges facing the industry understand the carrageenan, commonly used in industrial wastewater treatment technology. Based on the study of chemical flocculation of carrageenan squeezed water and the first washing liquid from the treatment. The requirements of the enterprise, choose the simple and feasible method for processing of squeezed water and the first washing solution, in order to handle after squeezing water can be reused, the first water washing solution can be improved. This paper draws the contents and results as follows: (1) flocculation squeezed water of carrageenan by polymerization aluminum chloride (PAC) flocculant, dosage of flocculant, pH, effects of temperature, sedimentation time effect on flocculation effect; polyacrylamide (PAM) as coagulant and PAC composite, PAM PAC study, Tim Dosage, temperature, the effect of pH on the flocculation effect. The results showed that PAC/PAM composite flocculant can effectively reduce the content of small molecules of carrageenan, improve the flocculation efficiency, effect of adding amount of PAC and pH on the water treatment effect is obvious. The removal rate of carrageenan and Al3+ residues as the index to determine the flocculant processing squeezed water better test process. The results showed that PAC/PAM composite flocculant of carrageenan squeezed water treatment effect is better than PAC; PAC, PAM were 2g/L, 15mg/L, pH 5-8, temperature 25-35 C, the settling time of 30min, under the above conditions, the small molecule carrageenan removal rate reached more than 90%, Al3+ residual the amount is less than 0.2mg/L, water color close to the distilled water, can be used in other water carrageenan production section. (2) due to the first washing liquid quality is complex, high alkalinity, high chroma, high COD, high chlorine and other characteristics, so that the first time The washing liquid is difficult to treat. The experiment using poly aluminum chloride (PAC), poly aluminum ferric sulfate (PAFS), polyferric sulfate (PFS), AlCl3 (CTS) and chitosan as flocculant for wastewater treatment experiment to determine PAC, PFS, CTS three as flocculant; choose four different types of polyacrylamide (PAM) as a coagulant, showed better effect of anionic polyacrylamide with molecular weight of 8 million. During the experiment, the first water alkalinity, after acid neutralization, then experiments with the COD and color removal rate as the index, species, effects of the dosage of flocculant, coagulant type, dosage and effect of pH on the flocculation effect. The results showed that the coagulant on the treatment effect is better than the flocculation reaction first wash water. From the experimental results can also be obtained for the first time, treatment of washing solution flocculation COD and chroma of the higher the amount of PAC added: The amount of 3.50g/L, PFS dosage 5.25g/L, PAM dosage of 0.15g/L, to be treated water for about 4-5 of pH, COD and color removal effect is the best, the removal rate of COD is 73.70%, the color removal rate is about 72.80%; for the first time washing liquid of high COD and low chroma, using the composite flocculant CTS/PAC/PAM the best treatment effect, when the amount of CTS was 0.10g/L, PAC dosage of 3.50g/L, dosage of PAM was 0.20g/L, the pending water pH adjusted to about 7, the floc composite flocculant for the first time washing liquid treatment effect is the best. In this condition, the removal rate of COD is about 54.20%, the removal rate of chroma 73.50%. in PAC/PAM composite flocculant carrageenan squeezed water, get a good treatment effect, basically meet the requirements of enterprises. Choose a suitable flocculant first washing liquid has better effect and improve water quality.

【学位授予单位】：上海应用技术学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X792

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