AWWA ACE65402

This powerpoint presentation begins by providing interesting facts concerning toxin removal and then examines several arsenic removal technologies and their residuals concerns, including: Ion Exchange - brine regenerant on-site disposal, highly concentrated liquid waste, non-selective technology - co-contaminants; Granular Iron/Titanium Media Systems (GIMS) - local attrition losses, backwash creates on-site discharge, saturated media disposal at local landfill, As concentration drives waste volume; Reverse Osmosis Concentrated liquid waste - local discharge; Coagulation/Filtration - local arsenic laden residuals created, landfill or local discharge; Titanium/Zeolites - local attrition losses, backwash creates on-site discharge, saturated media disposal at local landfill; and, Regenerable Media - off-site residuals disposal, vendor return. Two phases of residuals are presented and include: Liquid Phase Residuals - brines, concentrates, backwash, rinse water, pre-treatment chemicals and attrition particles; and, Solid Phase Residuals - spent media, membranes, filters, dewatered sludge. Regulatory aspects are outlined, along with arsenic leaching, residuals assessment tests, solid media leaching, residuals minimization, and theoretical treatment/wasting scheme. Includes tables, figures.