Comerton Anna M, Andrews Robert C, Bagley David M
Department of Civil Engineering, University of Toronto, 35 St. George Street, Toronto, Ontario, Canada M5S 1A4.
Water Res. 2005 Oct;39(16):3982-90. doi: 10.1016/j.watres.2005.07.014.
A membrane bioreactor and reverse osmosis (MBR-RO) system was developed to assess potential reuse applications of municipal wastewater. The objective of the study was to examine the water quality throughout the system with a focus on waterborne pathogens, disinfection by-products (DBPs) and nitrate. This paper will discuss the presence of these contaminants in MBR effluent and focus on their subsequent removal by RO. This study has shown that high quality reuse water can be produced from municipal wastewater through the use of an MBR-RO system. The water meets California Title 22 reuse regulations for non-potable applications and US EPA drinking water limits for trihalomethanes (THM) (80 microg/L), haloacetic acids (HAA) (60 microg/L), chlorite (1.0 mg/L), total coliform (not detectable), viruses (not detectable), and nitrate/nitrite (10 mg N/L). However, THM formation (182-689 microg/L) attributed to cleaning of the MBR with chlorine and incomplete removal by subsequent RO treatment resulted in reuse water with THM levels (40.2+/-19.9 microg/L) high enough to present a potential concern when considering drinking water applications. Nitrate levels of up to 3.6 mg N/L, which resulted from incomplete removal by the RO membrane, are also a potential concern. A denitrification step in the MBR should be considered in potable water applications.
开发了一种膜生物反应器和反渗透(MBR-RO)系统,以评估城市废水的潜在回用应用。该研究的目的是检查整个系统的水质,重点关注水传播病原体、消毒副产物(DBP)和硝酸盐。本文将讨论这些污染物在MBR出水的存在情况,并重点关注它们随后通过RO的去除情况。本研究表明,通过使用MBR-RO系统,可以从城市废水中生产出高质量的回用水。该水符合加利福尼亚州第22号非饮用水回用法规以及美国环境保护局(US EPA)对三卤甲烷(THM)(80微克/升)、卤乙酸(HAA)(60微克/升)、亚氯酸盐(1.0毫克/升)、总大肠菌群(未检出)、病毒(未检出)和硝酸盐/亚硝酸盐(10毫克氮/升)的饮用水限值。然而,由于用氯清洗MBR以及随后的RO处理去除不完全导致的THM生成(182-689微克/升),使得回用水中的THM水平(40.2±19.9微克/升)足够高,在考虑饮用水应用时可能会引起关注。RO膜去除不完全导致的高达3.6毫克氮/升的硝酸盐水平也是一个潜在问题。在饮用水应用中应考虑在MBR中设置反硝化步骤。