臭氧活性炭对地表水中藻毒素的去除效能

发布时间：2018-05-16 10:08

本文选题：臭氧 + 粉末活性炭(PAC)　；参考：《吉林建筑大学》2017年硕士论文

【摘要】：随着原水水源微污染问题的加剧,地表水藻类的爆发所产生的藻毒素日渐威胁着人们的健康生活,藻毒素可引起皮肤过敏、呼吸系统衰竭甚至成为肝肿瘤促进剂,具有很强的致病性,然而常规水处理工艺对其的处理效果非常有限,为了降低水体中藻毒素的浓度,探索新的处理工艺十分必要。首先,本文研究了臭氧—活性炭工艺对藻毒素MC-LR的去除效果。综合考虑臭氧对MC-LR、有机物、浊度的去除能力,确定了最佳臭氧投加量为1.5mg/L。此浓度臭氧与35mg/L粉末活性炭联用时,对MC-LR、UV_(254)、浊度的去除率分别达到84.86%、63.36%、67.46%。将臭氧—活性炭工艺与高锰酸钾—活性炭工艺对微污染原水的去除能力进行了对比实验。通过小试实验确定了高锰酸钾最佳投量为1.0mg/L,与35mg/LPAC联用时对MC-LR去除率为33.17%,浊度仅为7.84%、UV_(254)仅为33.4%,可见,臭氧—活性炭工艺对微污染原水的处理效果优于高锰酸钾与活性炭联用。其次,用20%磷酸、20%氨水分别对粉末活性炭进行改性实验,扫描电镜观察其外观形貌并用Bohem滴定法对表面官能团进行测定。不同的改性过程改变了活性炭的物理化学结构。磷酸氧化改性后,降低了比表面积,增加了表面酸性基团,降低了零电荷点;氨水改性处理后,则升高了比表面积,并增加了表面碱性官能团,提高了零电荷点。静态吸附实验研究了不同吸附时间、温度、pH条件下三种活性炭对有机物的吸附能力。结果表明,活性炭对有机物的最佳吸附时间在120min左右;升高温度有利于增强活性炭的吸附能力,活性炭对有机物的吸附过程为吸热过程;碱性条件下更适合发挥活性炭的吸附作用。然后,进行了未改性炭、磷酸改性炭、氨水改性炭三种活性炭对MC-LR、浊度、有机物的去除实验。结果显示,三种活性炭对藻毒素的去除能力顺序为:氨水改性炭未改性炭磷酸改性炭;对有机物吸附能力顺序为:氨水改性炭未改性炭磷酸改性炭;未改性炭及磷酸改性炭对浊度的去除效果相近,但都低于氨水改性炭对浊度的吸附能力。在此基础上,将1.5mg/L臭氧与不同浓度氨水改性PAC联用,当投量为45mg/L时对MC-LR的去除率可达到90.54%。出水浊度仅为0.56NTU,去除率为86.7%。对UV_(254)、TOC、CODMn去除率依次为:63.16%、60.91%、42.86%。由此可见,臭氧与氨水改性PAC联用时对微污染原水的处理效果较与未改性活性炭联用更理想。最后,利用本次实验所得的大量研究数据,借助MATLAB软件建立MC-LR多元线性回归预测模型,以MC-LR作为被解释变量,以药剂投加量、浊度、UV_(254)为解释变量。结果显示,多元线性回归预测模型在7种不同工艺下对MC-LR的预测效果均理想,MC-LR与药剂投量、浊度、UV_(254)具有很强的线性相关性。R2值维持在0.9847~1.0000之间。
[Abstract]:With the micro-pollution of raw water sources, the algae toxin produced by the surface water algae explosion is threatening people's healthy life day by day. Algae toxin can cause skin allergy, respiratory system failure and even become liver tumor promoter. In order to reduce the concentration of alga toxin in water, it is necessary to explore a new treatment process. Firstly, the removal efficiency of algal toxin MC-LR by ozone-activated carbon process was studied. Considering the removal ability of ozone to MC-LR, organic matter and turbidity, the optimum ozone dosage was determined to be 1.5 mg 路L ~ (-1) 路L ~ (-1) 路L ~ (-1) O _ (3). When this concentration of ozone was combined with 35mg/L powder activated carbon, the turbidity removal rate of MC-LRV / UV _ (254) was 84.86 ~ 63.36% and 67.46% respectively. The removal capacity of micro-polluted raw water by ozone activated carbon process and potassium permanganate activated carbon process was compared. The optimum dosage of potassium permanganate is 1.0 mg / L, the removal rate of MC-LR and turbidity is 33.17 and 7.84g / L, respectively. The results show that the ozonic-activated carbon process is better than potassium permanganate and activated carbon in the treatment of micro-polluted raw water. Secondly, the powdered activated carbon was modified with 20% Phosphate and 20% ammonia respectively. The morphology of the activated carbon was observed by scanning electron microscope and the surface functional groups were determined by Bohem titration. Different modification processes change the physical and chemical structure of activated carbon. After phosphoric acid was oxidized, the specific surface area was decreased, the surface acidic group was increased, and the zero charge point was decreased. After ammonia treatment, the specific surface area was increased, and the surface alkaline functional group was increased, and the zero charge point was increased. Static adsorption experiments were conducted to study the adsorption capacity of three kinds of activated carbon for organic matter under different adsorption time and temperature and pH. The results showed that the optimum adsorption time of activated carbon for organic matter was about 120min, and the adsorption capacity of activated carbon was enhanced by increasing temperature, and the adsorption process of activated carbon to organic matter was endothermic. The adsorption of activated carbon is more suitable under alkaline conditions. Then, the removal of MC-LR, turbidity and organic matter by three kinds of activated carbon, unmodified carbon, modified carbon with phosphoric acid and modified carbon with ammonia water, was carried out. The results showed that the order of removal ability of three kinds of activated carbon to alga toxin was: ammonia modified carbon unmodified carbon phosphoric acid modified carbon the order of adsorption ability of organic matter was ammonia water modified carbon unmodified carbon phosphoric acid modified carbon. The turbidity removal efficiency of unmodified carbon and phosphoric acid modified carbon was similar, but lower than that of ammonia modified carbon. On this basis, when 1.5mg/L ozone was combined with different concentration of ammonia water to modify PAC, the removal rate of MC-LR could reach 90.54 when the dosage was 45mg/L. The turbidity of effluent is only 0.56 NTU and the removal rate is 86.7%. The removal rate of COD _ (mn) was: 63.16% and 42.86% respectively. It can be seen that the treatment of micro-polluted raw water with ozone and ammonia modified PAC is better than that with unmodified activated carbon. In the end, a multivariate linear regression prediction model of MC-LR is established by using MATLAB software based on a large amount of data obtained from this experiment. MC-LR is taken as the explanatory variable, and the dosage of medicament and turbidity is taken as the explanatory variable. The results showed that the prediction effect of multivariate linear regression model on MC-LR in 7 different processes was ideal. The linear correlation between MC-LR and dosage of MC-LR, turbidity and UV254) was very strong. R2 value maintained between 0.9847 and 1.0000.
【学位授予单位】：吉林建筑大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X52

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