MVR蒸发技术在废水处理中的应用研究

Study on the application of MVR evaporation technology in wastewater treatment

随着环境污染和水资源短缺的加剧,对于工业废水的排放要求日趋严格,常规的废水处理技术已无法满足废水的处理要求,尤其是高含盐、高有机物、高毒性的难降解废水,其有效处理仍然是难点。为满足国内对高难度废水的处理要求,采用MVR蒸发技术,通过卧式降膜蒸发装置,分别对高盐废水、焦化废水RO浓缩液和垃圾渗滤液NF浓缩液进行中试处理。结果表明,该技术可对上述废水进行10~20倍的有效浓缩处理,减量化效果明显,且蒸馏水出水水质良好,可满足排放或回用的要求。废水处理产出1 t蒸馏水的最高电耗为25.1 kW·h,电价按0.6元(/kW·h)计,运行成本可控制在15.1元以下,与管网式反渗透(STRO)工艺处理焦化废水的运行成本(吨水处理成本为10.48元,按最佳水回收率55%折算,产水成本为19.05元/t)相比,具有一定的节能优势。采用MVR卧式降膜蒸发技术作为废水的深度处理技术是可行的,具有广阔的应用前景,值得深入研究和推广。

With the aggravation of environmental pollution and water shortage,the requirements for industrial waste⁃water discharge are becoming more and more strict.The conventional wastewater treatment technology can no longer meet the requirements of wastewater treatment,especially refractory wastewater with high salinity,high organic matter and high toxicity,whose effective treatment is still difficult.In order to meet the domestic treatment require⁃ments for high-concentration wastewater,MVR evaporation technology was adopted to treat high-concentration brine,coking wastewater RO concentrate and waste leachate NF concentrate by horizontal falling-film evaporator in a pilot plant,respectively.The results showed that MVR evaporation technology could effectively concentrate the wastewater by 10-20 times,with obvious reduction effect,and the distilled water quality was good,which met the requirements of discharge or reuse.The electricity consumption per ton of distilled water output was 25.1 kW·h.The electricity price was calculated at 0.6 yuan/(kW·h),and the operation cost could be controlled below 15.1 yuan.Compared with the operating cost of space tube reverse osmosis(STRO)process for treating coking wastewa⁃ter(cost was 10.48 yuan/t,and the best water recovery rate of 55%,the cost of produced water was 19.05 yuan/t),it had certain energy-saving advantages.The use of MVR horizontal falling-film evaporation technology as advanced treatment technology for wastewater is feasible and has a broad application prospect,which is worthy of in-depth study and promotion.