AWWA MTC95024

Based on recent health effects data, the MCL for arsenic (As) may be lowered from 50 to 2-10 ug/L in the near future; many source waters contain arsenic at levels near 5 ug/L. A comprehensive, comparative study is underway to define arsenic treatment options; among other processes, membranes are being investigated. This paper looks at several surface water sources which contain As spiked at a total concentration of approximately 20 to 50 ug/L. For these sources, arsenic has been characterized through size fractionation using various bench-scale filters (10, 1, 0.45, and 0.1 um) and ultrafilters (30,000, 10,000, 3,000, 1,000 and 500 daltons). Removals of these various As forms are being tracked through each of several different nanofiltration (NF) modules (spiral wound), one ultrafiltration (UF) module (spiral wound and hollow fiber), and one microfiltration (MF) module. The authors also report on As size distributions in the various source waters and rejections observed for the various types of membranes. Also studied is the preoxidation of arsenite to arsenate prior to NF as a treatment option for groundwater sources where arsenite may be the predominant form of As.

Product Details

Published:

01/01/1995

ISBN(s):

0898678153

Number of Pages:

7

File Size:

1 file , 250 KB