膜蒸馏法处理焦化反渗透浓水的试验研究

发布时间：2018-02-17 03:24

  本文关键词： 反渗透浓水 焦化废水 真空膜蒸馏 Fenton氧化 石灰/纯碱软化　出处：《山东建筑大学》2017年硕士论文　论文类型：学位论文

【摘要】：焦化废水是煤化工生产过程中产生的污水,双膜工艺(微滤/超滤-反渗透)在焦化废水深度处理方面得到广泛应用,然而反渗透的产水率只有70%~75%,会产生25%~30%的反渗透浓水。随着工业污水“零排放”要求的提出,寻求处理效果更好、工艺稳定性更强、运行费用更低的反渗透浓水处理工艺,实现废水零排放目标,已经成为煤化工发展的自身需求和外在要求。论文以华北某焦化企业污水深度处理站反渗透浓水为研究对象,开展焦化反渗透浓水的膜蒸馏处理实验室试验研究,探索构建预处理+膜蒸馏的组合处理工艺,主要研究结论如下:采用石灰/纯碱软化法对焦化反渗透浓水进行软化处理可有效降低原水硬度。当原水硬度为763.4mg/L,Ca(OH)_2投加量为400mg/L、Na_2CO_3投加量为720mg/L、总硬度去除率为68.3%,总硬度下降为242.0mg/L,吨水处理药剂费用为1.17元。Fenton氧化法相对于粉末活性炭吸附法,具有去除效率高、药剂费用低等优点,可有效降低焦化反渗透浓水中有机物含量。当原水CODcr为308.3mg/L,在pH为4、H_2O_2/CODcr质量比为1:1、H_2O_2/Fe2+摩尔比为20:1条件下,CODcr去除率为53.73%,吨水处理药剂费用约为1.4元。真空膜蒸馏法可有效处理焦化反渗透浓水,适宜的工艺运行参数为进料温度60℃、冷侧真空度0.095Mpa、进料流量1.5L/min;试验中膜蒸馏出水TDS去除率高达99.9%,CODcr去除率在90%以上,电导率稳定在10 us/cm以下。反渗透浓水经预处理的膜蒸馏对比试验结果显示,软化+Fenton氧化+真空膜蒸馏组合工艺具有良好处理效果,膜蒸馏过程中产水通量衰减变缓,出水CODcr20mg/L,TDS10mg/L,电导率10us/cm,出水水质优良,是可行的焦化反渗透浓水处理工艺。膜清洗研究结果表明,采用盐酸、EDTA、次氯酸钠对膜组件进行组合清洗,最高可恢复93%的膜通量。
[Abstract]:Coking wastewater is a kind of wastewater produced in coal chemical industry. The dual-membrane process (microfiltration / ultrafiltration reverse osmosis) is widely used in advanced treatment of coking wastewater. However, the water production rate of reverse osmosis is only 70%, which will produce 25% 30% of concentrated reverse osmosis water. With the requirement of zero discharge of industrial sewage, the process of treating concentrated reverse osmosis water with better treatment effect, stronger process stability and lower operating cost will be sought. Realizing the zero discharge target of wastewater has become the demand and external requirement of coal chemical industry development. In this paper, the reverse osmosis concentrated water of a coking plant sewage treatment plant in North China is taken as the research object. The experimental study on membrane distillation treatment of concentrated water from reverse osmosis of coking plant was carried out, and the combined treatment process of pretreatment membrane distillation was explored. The main conclusions are as follows: the hardness of raw water can be effectively reduced by lime / soda softening method in the treatment of thick reverse osmosis water of coking plant. When the hardness of raw water is 763.4 mg / L, the addition amount is 400mg / L / L / L / L / L / s / L / s / s / s / s / s / s / s / s / s, the total hardness removal rate is 68.3mg / L, and the total hardness is 68.3mg / L, respectively, and the total hardness removal rate is 68.3mg / L and the total hardness removal rate is 68.3%. The degree dropped to 242.0 mg / L, and the cost of water treatment was 1.17 yuan. Fenton oxidation was compared with powder activated carbon adsorption. It has the advantages of high removal efficiency, low cost and so on. When the CODcr of raw water is 308.3 mg / L, the removal rate of CODcr is 53.73 and the cost of water treatment is about 1.4 yuan under the condition that the mass ratio of the raw water is 308.3 mg / L, and the mass ratio of 1: 1 / C / CODcr is 1: 1. The ratio of Fe2 / Fe2 is 20: 1. Treatment of reverse osmosis concentrated water in coking plant, The suitable process parameters are feed temperature of 60 鈩，

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