Evaluation of point-of-use treatments and biochar to reduce 1,2,3-trichloropropane (TCP) contamination in drinking water

Abstract

In rural agricultural regions characterized by historical fumigant use and in industrial areas, groundwater contamination by 1,2,3-trichloropropane (TCP) poses a significant environmental and health concern due to its potential as a carcinogen. This study evaluates the effectiveness of commercially available water pitchers equipped with carbon filters and almond biochar for point-of-use TCP treatment. The study found that the filters were able to remove TCP (>98%) from untreated groundwater during their lifespan, and different filter brands with varying flow rates showed no significant difference in TCP removal. These results suggest that these pitchers may provide a simple and efficient short-term solution. Furthermore, the study explored the feasibility of low-cost, locally sourced biochar derived from almond shells as a sustainable alternative to traditional carbon feedstocks. Batch isotherm tests, BET analysis, X-ray photoelectron spectroscopy (XPS) analysis, and scanning electron microscopy (SEM) imaging were used for biochar studies. The study found that the almond biochar used had a low surface area and total pore volume in comparison to commercial Granular Activated Carbons (GACs) and that more than half of the total area was composed of micropores (< 2 nm), while XPS surveys revealed the presence of Calcium, Phosphorus, and Potassium on the char’s surface. Finally, batch isotherm studies show that almond biochar exhibits lower TCP absorption efficiency compared to commercially available granulated carbon. However, further research into biochar produced under varied pyrolysis conditions is needed to determine its potential as a substitute for coconut shells. These findings can provide affected communities with information on efficient and cost-effective treatment technologies of TCP at the domestic well and household levels.