论文部分内容阅读
采用热碱水洗-机械脱水工艺对国内某油田区的石油污染土壤进行处理.考察了热碱水洗条件(包括NaOH质量分数、液固比、洗涤温度)对含油土壤脱油效果的影响,及絮凝剂种类、质量分数对热碱水洗法处理后的含油污泥过滤脱水性能的影响.结果表明,残余油质量分数随NaOH质量分数及液固比的升高呈现先下降后上升的趋势,而随温度的升高呈现持续下降的趋势.在探究含油污泥脱水性能实验中发现铝盐及铁盐类絮凝剂对于高碱性污泥的适应性较差,而钙盐可以很好地破坏油水细砂混合层,有效地改善含油污泥过滤脱水性能.综合考虑含油污泥的过滤速率、滤饼含水率及滤饼残余油质量分数,0.8％的CaCl2溶液处理效果最佳.“,”The treatment of petroleum contaminated soils by hot alkaline water combined with mechanical dewatering process is conducted in an oil field in China.The effect of NaOH concentration,alkaline water-oily sludge ratio and temperature on the oil-removal effect is studied.The factors affecting the filtration and dewatering performance of the petroleum contaminated soils treated by hot alkaline water,such as the types and contents flocculating agents,are also investigated.The results show that residual oil is firstly decreased and then increased with increasing the concentration of NaOH and alkaline water-oily sludge ratio.But,the increase in temperature leds to th drastical decrease in residual oil.The proper parameters for hot alkaline water treatment are 0.2％ of NaOH,4:1 of alkaline water-oily sludge ratio and 80℃ of temperature.In the experiments of dewatering,the flocculation capability of AlCl3,Fe2 (SO4) 3 and PAC are strongly influenced by pH.The Ca2+ ions effectively incresase the flocculation of tiny particles by forming Ca(OH) + and Ca(OH) 2,thus greatly improving the filtration and dewatering performance.When the concentration of CaCl2 is 0.8％,the best filtration and dewatering performance can be achieved based on the filtration rate,moisture content and residual oil ratio in the petroleum contaminated soils.