煤制氢含氰废水的处理工艺研究

摘要

采用混凝-光催化氧化(UV-NaClO或UV-H2O2)组合工艺处理某石化企业煤制氢生产中排放的含氰废水,并在实验室研究(小试)的基础上进行了放大规模试验(中试).小试结果表明:混凝工段的适宜工艺条件为不调节混凝pH、混凝剂投加量200 mg/L;相同氧化剂投加量下H2O2溶液氧化降解氰化物的能力较NaClO溶液强,后者虽可将总氰化物质量浓度降至1 mg/L以下,但氧化剂消耗量过大.经反复试验和综合分析,将中试工艺改进为沉降-UV-H2O2工艺.中试结果表明:采用沉降-UV-H2O2工艺处理含氰废水,处理效果显著且稳定,处理成本低廉(约为8元/m3),值得推广.%The cyanide-containing wastewater in production of hydrogen from coal in a petrochemical plant was treated by coagulation - photocatalytic oxidation (UV-NaClO or UV-H2O2)combined process. The pilot-scale test was carried out on the basis of small-scale test. The results of small-scale test showed that:The optimum conditions for coagulation process were initial pH and coagulant amount 200 mg/L;With the same amount of oxidant,the H2O2solution had higher cyanide-degrading ability than NaClO solution,and the latter could decrease the total cyanide mass concentration to below 1 mg/L but the consumption of oxidant was too much. After a lot of test and analysis,the process for pilot-scale test was modified as sedimentation - UV-H2O2process. The results of pilot-scale test showed that the sedimentation - UV-H2O2process had good and stable effect on treatment of cyanide-containing wastewater with low cost (about 8 yuan/m3)thus deserving popularization.