Korshin, GregoryWalters, Samuel2022-07-142022-07-142022Walters_washington_0250O_24085.pdfhttp://hdl.handle.net/1773/48877Thesis (Master's)--University of Washington, 2022Arsenic is a highly toxic contaminant of concern to many entities, notably for a landfill utility within King County (KC), where its high concentrations have been observed in landfill gas (LFG) condensate, a byproduct of the process of purifying landfill gas, and landfill leachate. This thesis focuses on the removal of arsenic from LFG condensate using micro-electrolysis (ME) implemented in fixed bed column and batch column reactor configurations. The fixed bed column experiments were conducted using a 1 L clear PVC column and a 3D printed module with detachable layers made of polylactic acid (PLA). The experiments consisted of a comparison of material of adsorbent used for treatment, height of individual treatment beds, pH of LFG condensate influent, and pretreatment of LFG condensate with granular activated carbon (GAC). These experiments showed that using either of a combination of GAC and zero valence iron (ZVI) or powder activated carbon (PAC) coated nano-ZVI resulted in a relatively high removal of arsenic within the fixed bed column, but only for a limited number of bed volumes. The pretreatment of LFG condensate using GAC had little effect on arsenic removal within fixed bed column. The fixed bed column experiments were halted in this study due to hydraulic blockages in the system albeit they may be continued at a later time. Micro electrolysis (ME) batch column treatment examined a wide variety of operating conditions, including pH of solution, adsorbent dose and composition, counterflow gas conditions, and filtration conditions. The experiments testing adsorbent conditions cover different adsorbent concentrations, always held constant at a ratio of 2:1 Fe:C, varied adsorbent addition methods, and staggered adsorbent addition times. These experiments were conducted to determine the combination of factors that would lead to the most effective removal of arsenic. Counterflow conditions included varying the method of flow in which the counterflow gas was added and whether the flow was constant or intermittent. The other important factor being tested was the filtration method. Testing whether or not samples needed to be filtered post-treatment, during treatment, or not at all could be an important factor when determining technology treatment efficiency. These experiments are ongoing and are in the process of being upscaled to treat more LFG condensate at once. The data showed a more effective treatment at a lower pH and a higher concentration, or dose, of adsorbent material. A flow through the solution during treatment of CO2 gas is necessary for arsenic removal, and experiments are ongoing to determine whether N2 is also an acceptable carrier gas for these experiments.application/pdfen-USnoneAntimonyArsenicLandfillMicro-electrolysisEnvironmental engineeringCivil engineeringThesis