火力发电厂废水的综合处理研究

发布时间：2018-02-01 21:59

本文关键词： 循环冷却水脱硫废水石灰絮凝石英砂锰砂粉煤灰　出处：《西安建筑科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：火电厂产生的废水、废气、废渣对环境的污染影响着人们生活，近来日益严重的雾霾与火力发电有一定关系。针对西安灞桥大唐电厂综合废水水样进行分析处理，用电厂粉煤灰处理脱硫废水，石灰法深度处理循环冷却水，出水循环回用，在水资源循环利用的同时实现了以废治废。针对电厂脱硫废水、循环冷却水的水质分析，采用该厂发电燃烧的残留粉煤灰处理脱硫废水，采用石灰混凝结合石英砂、锰砂过滤处理循环冷却水。探讨了粉煤灰投加量、温度、时间等因素对脱硫废水悬浮物、化学需氧量、氟化物、重金属铬、镉、锌、铅、铜的处理效果。针对废水水质通过添加石灰、絮凝剂，提高处理效果。单因素试验结果表明：在50ml脱硫废水中投加15g粉煤灰，pH值在8～9，聚合氯化铝10mg/L，聚丙烯酰胺1mL/L，石灰0.20g，30～40min就能得到较好处理效果。正交实验进一步优化了对脱硫废水的处理效果，结果表明粉煤灰投加5.0g、pH值9.0，聚合氯化铝10mg/L，聚丙烯酰胺1mL/L，石灰0.20g，40~50minCOD去除率达74.59%，悬浮物去除率55.58%，氟化物去除率98.34%，重金属Cu2+、Pb2+、Zn2+、Cr3+、Cd2+去除率分别为99.69%、97.88%、98.29%、99.76%、97.29%，得到较满意的结果。用石灰法混凝结合石英砂、锰砂混料过滤处理电厂循环冷却水。结果表明：石灰600mg/L，，聚合氯化铝30mg/L，聚丙烯酰胺0.5mg/L～1.5mg/L处理效果较好；出水pH值在8.5～8.9之间。碱度去除率86.09%，总硬度去除率为53.58%，悬浮物去除率达82.18%，CODcr去除率为32.35%。助凝剂聚丙烯酰胺明显加快了沉降速度。石英砂/锰砂混层滤料除铁试验表明，石英砂/锰砂比例为3:7滤料对铁的吸附效果与100％锰砂滤料的效果相差无几，铁去除率达90％以上。调整原水的pH值6.5～7.5，再通入石英砂/锰砂为3:7的混层滤料，除铁效果最佳。
[Abstract]:The pollution of waste water, waste gas and waste residue from thermal power plant affects people's lives. Recently, the increasingly serious haze is related to thermal power generation. The comprehensive waste water sample of Xi'an Baqiao Datang Power Plant is analyzed and treated. The desulfurization wastewater is treated with power plant fly ash, the circulating cooling water is treated by lime process, the water is recycled and recycled, and the waste is treated with waste water at the same time. In view of the water quality analysis of desulfurization wastewater and circulating cooling water in power plant, the residual fly ash from power generation and combustion in this plant is used to treat desulfurization wastewater, lime coagulation combined with quartz sand and manganese sand filtration to treat circulating cooling water. The dosage of fly ash is discussed. The effect of temperature and time on the treatment of suspended matter, chemical oxygen demand, fluoride, chromium, cadmium, zinc, lead and copper in desulphurization wastewater. The results of single factor experiment showed that the best treatment effect could be obtained by adding 15g fly ash to 50ml desulfurization wastewater with pH value of 8g / L, polyaluminium chloride 10mg / L, polyacrylamide 1mL / L, lime 0.20g / L 30g / 40min. Treatment effect of desulphurization wastewater, The results showed that the removal rates of COD, suspended solids, Cu2, Pb _ 2Zn _ 2Cr _ 3H _ 3C _ 2 and CD _ 2 in fly ash, polyaluminium chloride, polyacrylamide and polyacrylamide were 74.59, 55.58, 98.34, 98.69 and 97.88, respectively. The results showed that the removal rates of fly ash were 5.0 g / L, 10 mg / L, 1 mL / L of polyacrylamide, 0.20 g / L of lime and 0.20 g / L of lime respectively, and the removal rates of suspended solids were 55.58, 98.34 34, respectively, and the removal rates of heavy metal Pb2Zn2Cr3 / CD _ 2 were 99.6969 ~ 97.88 and 99.7697.299.29, respectively. The circulating cooling water of power plant is treated by lime coagulation combined with quartz sand and manganese sand. The results show that lime 600 mg / L, polyaluminium chloride 30 mg / L, polyacrylamide 0.5 mg / L and polyacrylamide 1.5 mg / L have better treatment effect. The pH value of effluent is between 8.5 ~ 8.9.The removal rate of alkalinity is 86.09, the removal rate of total hardness is 53.58, the removal rate of suspended matter is 82.18 and the removal rate of CODcr is 32.355.The sedimentation rate of coagulant polyacrylamide is obviously accelerated. The adsorption effect of quartz sand / manganese sand on iron is similar to that of 100% manganese sand filter material, and the iron removal rate is above 90%. The best iron removal effect is to adjust the pH value of raw water to 6.5% 7.5 and then pass through the mixed layer filter material with quartz sand / manganese sand of 3: 7.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：X773

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