吸附沉淀高级氧化法处理鞣酸铅废水的研究

发布时间：2019-02-14 15:04

【摘要】：鞣酸铅是鞣酸与金属铅离子反应生成的多核络合物,常作为火箭和导弹的固体推进剂,在提高燃速和降低压力指数方面的具有良好的催化燃烧效果。鞣酸铅生产过程中产生大量的母液和洗涤废水,该废水呈深红棕色,色度值高达100,pH值为5,COD_(Cr)值约为4515.0 mg/L,Pb~(2+)含量约为27.32 mg/L。该废水同时含有难降解有机物和重金属,不仅会严重污染生态环境,而且限制企业绿色环保生产。因此,处理鞣酸铅废水成了一项企业急迫需要解决的任务。本课题结合吸附、沉淀、高级氧化三种方法综合处理鞣酸铅废水,确定了各个处理过程的最佳操作参数,并且探讨了鞣酸铅废水的降解机理。首先,采用沉淀、吸附、沉淀-吸附、吸附-沉淀四种方法对废水进行预处理。通过对各种方法的预处理结果比较分析,发现使用D201碱性树脂吸附组合CaO粉末沉淀处理效果最好。通过D201树脂吸附,废水中COD_(Cr)和Pb~(2+)的去除率分别达到74.4%和98.2%;通过CaO沉淀预处理,废水COD_(Cr)去除率达到57.1%。D201树脂用浓度为0.1 mol/L的HCl和质量分数为15%的NH_4Cl洗脱再生,重复利用。由于D201树脂和CaO处理过的废水COD_(Cr)和色度达不到排放标准,论文中考察光催化高级氧化法进行深度处理,光催化法深度处理的最佳反应条件:室温,pH为7.0,P25用量1.6 g/L,H_2O_2用量6 mL/L。在此条件下,废水COD_(Cr)降低到87.5 mg/L,去除率为82.3%,处理后达到《航天推进剂水污染排放标准》(GB14374-93)的废水排放要求。此外,论文中也考察了光芬顿法深度处理该废水,光芬顿法的最佳工艺参数:pH值为4.0,H_2O_2用量4 mL/L,n(H_2O_2/Fe~(2+))为15。废水COD_(Cr)去除率达到85%,出水COD_(Cr)约为75 mg/L。最后,采用紫外-可见光谱仪对光芬顿法处理的废水产生的中间产物进行了分析,结果表明:鞣酸先水解为没食子酸和六元环葡萄糖,然后依次被氧化为烯烃、醛酮、羧酸,最后矿化为CO_2和H_2O。
[Abstract]:Lead tannate is a polynuclear complex formed by the reaction of tannic acid with lead metal ions. It is often used as solid propellant of rocket and missile and has good catalytic combustion effect in increasing burning rate and reducing pressure index. A large amount of mother liquor and washing wastewater were produced during the production of lead tannate. The wastewater was crimson brown, and the chroma value was as high as 100g pH = 5 mg/L,Pb~ _ (Cr) = 4515.0 mg/L,Pb~ (2), about 27.32 mg/L.. The wastewater contains both refractory organic matter and heavy metals, which not only pollutes the ecological environment seriously, but also restricts the green production of enterprises. Therefore, the treatment of lead tannate wastewater has become an urgent task for enterprises to solve. Combined with adsorption, precipitation and advanced oxidation, the optimal operation parameters of each treatment process were determined, and the degradation mechanism of lead tannate wastewater was discussed. Firstly, the wastewater was pretreated by precipitation, adsorption, precipitation-adsorption and adsorption-precipitation. By comparing and analyzing the pretreatment results of various methods, it is found that D201 alkaline resin adsorption combined with CaO powder precipitation treatment is the best. The removal rates of COD_ (Cr) and Pb~ (2) reached 74.4% and 98.2% respectively by D201 resin adsorption. After pretreatment with CaO precipitation, the removal rate of COD_ (Cr) from wastewater reached 0.1 mol/L HCl and 15% NH_4Cl, and was reused and reused. Because the COD_ (Cr) and chromaticity of the wastewater treated with D201 resin and CaO could not meet the discharge standard, the optimum conditions of advanced photocatalytic oxidation for advanced treatment were investigated in this paper: room temperature, pH = 7.0. Consumption of P25 1.6 g / L Under these conditions, the removal rate of wastewater COD_ (Cr) is 82.5 mg/L, and the wastewater discharge requirement of Space propellant Water pollution discharge Standard (GB14374-93) is reached after treatment. In addition, the optimal technological parameters of the optical Fenton method for the advanced treatment of the wastewater were also investigated. The pH value of the method was 4.0 / H _ S _ 2O _ 2 4 mL/L,n (H _ 2O _ 2O _ 2 / Fe ~ (2) = 15. The COD_ (Cr) removal rate of wastewater is 85 and the COD_ (Cr) of effluent is about 75 mg/L.. Finally, the intermediate products of wastewater treated by light Fenton process were analyzed by UV-Vis spectrometer. The results showed that tannic acid was hydrolyzed into Gallic acid and hexagonal cyclodextrose, and then oxidized to olefins, aldehydes and carboxylic acids. Finally, the mineralization is CO_2 and H _ 2O.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X789

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