原水性质对纳滤去除三嗪类除草剂的影响

为考察原水性质(water matrix)对纳滤去除三嗪类除草剂的影响，以某市河水及管网水配制的5mg／L的农药溶液为对象，研究了4种纳滤膜(DESAL51HL、UTC-20、UTC60)对其中阿特拉津和西玛津的截留率及水通量的变化．结果表明，相对于蒸馏水而言，河水及管网水能提高纳滤对农药的截留率，并降低水通量．对于河水和管网水引起相似的截留率提高和水通量减少，其机制设想为由于离子在膜表面或孔径内的吸附，导致了膜有效孔径的堵塞或变小，从而使更多的除草剂分子在通过膜的过程中被截留．河水和管网水中天然有机物的存在对纳滤膜截留有机物能力的影响较小．在选用的4种膜中，UTC-20不受原水水质的影响，对COD、硝酸盐等污染物有较高的去除率并保持较高的水通量．

Effect of water matrix on the removal of trizines pesticides by nanofil tration

The removal of two pesticides (atrazine and simazine) from different water matrix (distilled water, tap water and river water) was studied by using four types of nanofiltration membranes. Atrazine and simazine were added separately to the different water matrix at a concentration of 5 mg/l. Rejection of pesticides and water flux were measured. The rejection of atrazine was always higher than that of simazine; the highest rejections were obtained with UTC-20. Compared to distilled water,the rejection of pesticides was higher in river water and tap water, but the water flux was lower. This was mainly explained by ion adsorption inside the membrane pores or onto the membrane surface, which can narrow the membrane pores. Additionally, there was a small effect of NOM on rejection and flux. Considerable rejection of organic matter (measured as COD and UV absorbance at 254 nm ) was observed, in particular for the membrane with the smallest pores (UTC-20). This confirms the assumption that pore narrowing by ion adsorption influences the rejections and water fluxes. UTC - 20 was considered to be potentially a suitable one for drinking water production among the four used membranes in view of nitrate removal.