Wastewater Effluent effects on the Transport and Retention of As(V) in Desert Soils.

Chronic low-level exposure to arsenic has been found to increase health risks for cancer, skin lesions, and numerous other illnesses.  In January 2006, the EPA lowered the MCL for arsenic to 10 ppb.  This new standard has affected many communities, requiring them to develop procedures for lowering arsenic concentrations in their drinking water.   Disposal of the arsenic residuals is a problem that must be considered when developing such a procedure.  A simple and low cost solution to this problem is to land-apply the arsenic concentrates with the municipal wastewater effluent.  To insure the usefulness and safety of this disposal method, it is essential to investigate arsenic transport and retention on diverse soils in the presence and absence of wastewater effluent.   In this study, sorption and breakthrough curve experiments were performed on three texturally diverse soils collected from a land application facility in Columbus, New Mexico.  As(V) was applied with either municipal wastewater effluent or 0.01 M KNO₃ buffer to study the effects of effluent on As(V) transport through and retention on the soils.  Various models will be fit to examine their ability to describe As(V) transport over time under these two conditions.