ERMUSR Misc 05-10-2007 - Laserfiche WebLink

Home Browse Search

BY ARTURO A. BURBANO, SAMER S. ADHAM, { :~.. -;~ ,~ . sR ,~ :r _, AND WILLIAM R. PEARCE wide survey s a result of demographic expansion, many areas of the world face the challenge of ,meeting ever-increasing water demands. This situ- ation_~is particularly complex in arid regions where water resources are scarce and/or dangerously close to exhaustion (USGS, 2003). . For this reason, the use of nontraditional water sources such as sea- watet;'brackishgroundwate~`and reclaimed wastewater has become an attrac- tive alternarive for increasing water supplies for potable and nonpotable uses. '-A corrfinon chazacterstic`of these nontraditional water sources is their high coneentratio~ !of'totaldissolved solids (TDS). The US Environmental Protec- tion Agenc}~ has established a~guideline (i,e., secondary maximum contaminant level) ~~of 500 mg/L as TDS;foi- drinking water (AWWA, 1999). An arbitrary criterion has determined a TTZS concentration of 1,000 mg/L (excluding hard- ness) as t~e,upper salintty,~lirnitfor water suitable for human consumption (Bhattacharyya et a1, 2001): Yet in regions of the world such as Saudi Arabia and otlier:countnes inxhe Persian Gulf, water with salinity levels that exceed 1,000 mg/L is.used for domestic supply because less-saline water is scarce or unavailable':{A1-Salahwi, 1999). Water with TDS of approximately 3,000 mg/L or higher is considered too 'saline to drink. This category includes seawater and some brackish ground- - waters. whose TDS concentrations may vary from approximately 20,000 to :50,000 mg/Land .1.,000 to 10,000 mg/L, respectively. Reclaimed wastewater, which-;has a TDS content ranging from 600 to 1,400 mg/L, has become an increasingly popular alternative. water source in light of the new emphasis on water reuse (Alexander et al, 2003; Adham et al, 2001; Lozier et al, 2000). to of full-scale aesa[inati~~- esults from