Drying, analysis and gasification of biosolids and the use of iron(III) hydroxide impregnated corn pith for the removal of arsenic from water

In this research the ChemChar gasification method was used as a biosolid disposal alternative and for mass and volume reduction. Several uses of the char product produced by the ChemChar gasification process were explored. The gasification process resulted in a mass loss of 54% of the solid content while leaving the usable char product. The char product was used to facilitate the drying process necessary for all biosolid disposal methods. Using air as the drying medium, a mixture of two parts char to one parts saturated biosolids was found to dry the biosolids to a 97% in a period of 13 hours. The char product, both by itself and impregnated with humic and nitro-humic acids, was determined to be efficient at removing selected metals (Cd, Pb, Cu, and Zn) from wastewater. The char filter was found to remove the selected metals in the 90% range while the impregnated filters were capable of removing upwards of 97% of the metals from water with initial metal concentrations of 10 ppm. The capacity of the char product was tested for lead, copper and chromium and determined to be 0.012 mmol g-1 char, 0.01 mmol g-1 char, and 0.02 mmol g-1 char respectively.; The metals released during the gasification process were analyzed and it was determined that relatively low amounts of the metals are released during the ChemChar gasification process. Sulfur and chlorine were released in relatively high amounts, 10 mg g-1 biosolids +/- 0.05 and 21 mg g -1 +/- 0.02 respectively. A system consisting of a water condenser and a filter made from previously gasified biosolids was used to sequester the metals that were released in the offgas. The water condenser was unsuccessful at removing the metals released but the char filter was successful at sequestering the expelled metals.; A novel method for removing arsenic from drinking water was explored. Iron(III) hydroxide impregnated corn pith was found to be successful at removing arsenic at both lower (ppb range) and higher (ppm range) concentrations. Radiotracers of arsenic-76 were used to determine that the system was capable of removing upwards of 98% of both arsenic(III) and arsenic(V). The system was determined to be efficient at meeting upcoming EPA limits of 10 ppb, with a capacity of 60 mug g-1 (0.8 mumol As g-1). The breakthrough point of the system was determined to be 25 mg g-1, 0.33 mmol As g-1.