共聚醚合成过程废水的处理研究

发布时间：2018-08-01 11:14

【摘要】：共聚醚合成过程中会产生COD值大、难降解有机物含量多、水质水量多变的有机废水。Fenton法是一种常用的处理有机废水的高级氧化技术,但仅采用Fenton法难以对共聚醚废水进行达标处理。本研究采用微电解-Fenton法、UV-Fenton法、Fenton-混凝法以及微电解-UV/Fenton-混凝法四种Fenton组合工艺处理共聚醚废水,以COD去除率和色度值为指标,确定各方法的较佳工艺条件。得出了对共聚醚废水处理效果较好的组合工艺及其较佳的实验条件。采用微电解-Fenton法处理共聚醚废水,对30%H_2O_2投加量、初始pH值、反应时间、铁粉投加量和铁炭比进行了考察,得到较佳的实验条件为:30%H_2O_2投加量为40m L/L,初始pH值为1,反应时间4h,铁粉投加量为40g/L,铁炭比为1:4。该条件下处理后的共聚醚废水COD去除率达到93.6%,色度值仅为2.6度。采用UV-Fenton法处理共聚醚废水,对初始pH值、反应时间、FeSO_4·7H_2O投加量和n(H_2O_2)/n(Fe~(2+))进行了考察,得到较佳的实验条件:初始pH值为2,反应时间2.5h,FeSO_4·7H_2O投加量为18g/L,n(H_2O_2)/n(Fe~(2+))为40:1。在该条件下处理后的共聚醚废水COD去除率达到76.2%,色度值为13.1度。采用Fenton-混凝法处理共聚醚废水,对混凝剂种类、FeSO_4·7H_2O投加量、n(H_2O_2)/n(Fe~(2+))、FeCl_3投加量和PAM投加量进行了考察,得到较佳的实验条件:混凝剂为FeCl_3,FeSO_4·7H_2O投加量为24g/L,n(H_2O_2)/n(Fe~(2+))为27:1,FeCl_3投加量为5g/L,PAM投加量为600mg/L。在该条件下处理共聚醚废水,废水的COD去除率可达到58.7%,色度值仅为2.4度。采用微电解-UV/Fenton-混凝法对共聚醚废水进行处理,对UV/Fenton阶段pH值、FeSO_4·7H_2O投加量、30%H_2O_2投加量、FeCl_3投加量、PAM投加量五个主要的影响因素进行了考察,得到该组合方法的较佳实验条件为:UV/Fenton阶段pH值为2、30%H_2O_2投加量420m L/L、混凝剂PAM投加量为200mg/L、不需添加FeSO_4·7H_2O和FeCl_3。在较佳条件下处理后的共聚醚废水COD去除率达到98.5%,色度值为6.4度。从对共聚醚废水的处理效果来看,四种组合工艺中微电解-UV/Fenton-混凝法处理效果最好,经其处理过的共聚醚废水的COD值从33415 mg/L降低到500mg/L,满足《污水综合排放标准》(GB8976-1996)三级排放标准,色度值达到一级排放标准。微电解-Fenton法、UV-Fenton法、Fenton-混凝法对共聚醚废水均有一定的处理效果,可作为对共聚醚废水的预处理方法使用,其中微电解-Fenton法对于废水中的有机物去除率较高,COD去除率高达90%。混凝-Fenton法处理后的废水色度值相对较低,可用于处理色度值高,悬浮物、细小颗粒或者胶体含量高的共聚醚废水。
[Abstract]:In the process of synthesis of copolyether, the COD value is large, the content of refractory organic matter is high, and the organic wastewater with variable water quality and quantity is a common advanced oxidation technology for treating organic wastewater. However, it is difficult to treat polyether wastewater by Fenton process only. In this study, four kinds of Fenton combined processes of micro-electrolysis and Fenton-Fenton method and micro-electrolysis / UV / Fenton-coagulation process were used to treat the copolyether wastewater. The removal rate of COD and the value of chroma were taken as the index to determine the better process conditions of each method. The better combination process and the better experimental conditions for the treatment of co-polyether wastewater were obtained. The copolyether wastewater was treated by micro-electrolysis-Fenton process. The dosage of 30%H_2O_2, initial pH value, reaction time, the amount of iron powder and the ratio of iron to carbon were investigated. The results show that the optimum experimental conditions are as follows: (1) the volume of S _ 2O _ 2 is 40 mL / L, the initial pH is 1, the reaction time is 4 h, the dosage of iron powder is 40 g / L, and the ratio of iron to carbon is 1: 4. Under this condition, the COD removal rate of the treated copolyether wastewater reached 93.6 degrees and the chroma value was only 2.6 degrees. The copolyether wastewater was treated by UV-Fenton method. The initial pH value, the reaction time and the dosage of FeSO4 7H_2O and n (H_2O_2) / n (Fe2) were investigated. The optimum experimental conditions were as follows: initial pH value 2, reaction time 2.5hFeSO4 7H_2O dosage 18g / Ln (H_2O_2) / n (Fe2) = 40: 1. The COD removal rate of the treated copolyether wastewater was 76. 2% and the chroma value was 13. 1 degree. The Fenton-Coagulation method was used to treat copolyether wastewater. The dosage of coagulant FeSO4 7H_2O (H_2O_2) n (Fe2) + FeCl3 and the dosage of PAM were investigated. The optimum experimental conditions were obtained as follows: the dosage of coagulant FeClon 3 FeSO4 7H_2O was 24 g LLN (H_2O_2) n (Fe2) 27: 1 FeCl3 was 5 g / L PAM = 600mgL / L. The experimental conditions were as follows: the dosage of coagulant FeSO4 7H_2O was 24g / L (H_2O_2) n (Fe2) = 27: 1FeCl3 = 5 g / L PAM = 600mgL / L. Under this condition, the COD removal rate of the wastewater can reach 58.7 degrees, and the chroma value is only 2.4 degrees. The copolyether wastewater was treated by micro-electrolysis / UV / Fenton-coagulation method. Five main influencing factors were investigated on the pH value of FeSO4 7H_2O at UV/Fenton stage and the dosage of FeSO4 7H_2O. The optimum experimental conditions of the combined method are as follows: the pH value of the phase of 20 / UV / Fenton is 230 / 20 / L, the dosage of PAM is 200 mg / L, and the addition of FeSO_4 7H_2O and FeCl _ 3 is not necessary. The COD removal rate of the treated copolyether wastewater was 98.5 and the chroma value was 6.4 degrees under the optimum conditions. According to the treatment effect of co-polyether wastewater, the treatment effect of micro-electrolysis UV / Fenton-coagulation process is the best. The COD value of the treated copolyether wastewater is reduced from 33415 mg/L to 500mg / L, which meets the tertiary discharge standard of "sewage Comprehensive discharge Standard" (GB8976-1996). The chroma value is up to the first class emission standard. Micro-electrolysis-Fenton UV-Fenton-coagulation process can treat copolyether wastewater to some extent and can be used as a pretreatment method for co-polyether wastewater, in which micro-electrolysis Fenton-Fenton process has a higher removal rate of organic matter and COD removal rate is as high as 90%. Coagulation-Fenton process can be used to treat the wastewater with high chromaticity value, suspended matter, fine particles or high colloid content of co-polyether wastewater.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X783

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