受木屑污染雨水中氮的去除

采用过滤、混凝澄清和化学氧化法对受木屑污染的雨水中的氮进行了去除研究。实验结果表明90%氮在雨水中以溶解态存在,难以通过过滤、混凝澄清等物理方法去除。次氯酸钠氧化法能高效氧化水中的氨氮并以氮气的形式去除,氨氮的去除量同次氯酸钠剂量呈线性关系,去除1g氨氮需要8.86g活性氯(以Cl2计)。综合投加不同剂量的次氯酸钠后测定了水中余氯、总氮、氨氮等含量曲线,污水中氨氮优先于有机氮同次氯酸钠反应而去除,因而可控制加药量而避免产生大量消毒副产物(DBPS)。同时研究了加药后氧化还原电位(ORP),表明可通过ORP的变化为运行控制提供简便可靠的依据。

Study on Nitrogen Removal in Rainwater Palluted by Wood Chips

Filtration,coagulation and flocculation,and oxidation were used to remove the nitrogen from rainwater polluted by wood chips.The results showed that 90% of nitrogen in rainwater is soluble and can not be removed by filtration or coagulation/flocculation,but can be removed by reaction with NaClO:ammonia is oxidized as gaseous nitrogen.The relation between the removal quantity of ammonia and the dosage of NaClO was linear.The removal of 1 g ammonia needed 8.86 g active chlorine(Cl2).In combination of the relations between the dosages of sodium hypochlorite with residual chlorine,TN,N-NH3,etc.,it could be concluded that the reaction between ammonia and sodium hypochlorite is prior to other organic nitrogen in wastewater.Thus,the disinfecting by-products(DBPS) can be reduced by limited dosage of NaClO.The effect of dosage of NaClO on ORP was also studied for the control of the dosage in site.