Date of Award
Santa Clara University
The problem of arsenic contamination affects millions of people worldwide. A home-scale arsenic removal system could provide families in Nepal access to clean drinking water. It would also reduce the risk of adverse health issues that are associated with ingesting arsenic contaminated water. Our experiments show that using electrocoagulation is an effective method of removing arsenic from water. We were able to get the level of arsenic below 10 ppb in 60 minutes of treatment using various system configurations. We identified several parameters that affect the treatment process, the most important being the charge loading, or the amount of charge that passes through the solution during treatment. The more current supplied, the faster the treatment, but too much current is inefficient. We identified an effective range for charge loading to be between 150 and 180 C/L. For a home-scale arsenic removal system to be used in Nepal, we recommend using a 6V rechargeable battery supplying 170 C/L of charge to a 3.5 gallon bucket (13L) and a electrochemical cell which consists of five 4"x4" steel plates. Water treated in the first stage then moves to a sand filter containing 10 inches of fine sand and a simple underdrain nozzle. The water will then be stored in a large container. With the battery constraint reduced or removed, the system can be upgraded to a larger treatment system or even an automated semi-continuous flow system. The design of this removal system is manufacturable, but is dependent upon the identification of a local manufacturer to maintain low cost. A manufacturer can be identified after field testing to observe the system's performance in the intended environment is completed.
Alferness, Megan and Casares, Alexandria, "Design And Evaluation Of A Home- Scale Arsenic Removal System" (2014). Civil, Environmental and Sustainable Engineering Senior Theses. 26.