Arsenic removal from household drinking water by biochar and biochar composites: a focus on scale up

ALCHOURON, JACINTA; BURSZTYN FUENTES, AMALIA LARA; MUSSER, ABIGAIL ; VEGA, ANDREA; MOHAN, DINESH; PITTMAN JR., CHARLES U.; MLSNA, TODD; NAVARATHNA, CHANAKA M.

Sustainable Biochar for Water and Wastewater Treatment

Alsevier

Año: 2022;

Providing drinking water with safe arsenic (As) levels is a current, major challenge worldwide. The main As source is geogenic, and different water-solid phase interactions and geochemical processes control the As mobilization. As concentrations in drinking water have been reported up to 200x the WHO recommended limit of 10 μg L-1. Adsorption is a very attractive, widely employed and alternative to other conventional remediation techniques since it is a cost-effective, simple-to-operate technique and generates lower environmental impacts. The design and synthesis of different biochars (BCs) and BC composites that exhibit arsenic adsorption potential for many types of aqueous environments were thoroughly examined over the last decade. Many BC and BC-derived composites sorption capacities were obtained only under controlled conditions, usually in batch systems on a laboratory scale. Column tests are scarce. Hence, knowledge gaps exist concerning how designed adsorbents perform in realistic conditions at larger working scales. Additionally, there are no updated documents compiling the recent advances on scaled-up BC water treatment for household As-safe drinking water.Understanding on-going scale-up experiences is essential to developing economical water treatment methods to meet the urgent safe drinking water needs. This chapter presents an overview of the currently assessed BC-based adsorbents and methodologies for As removal. BCs and modified-BCs used for arsenic decontamination are reviewed and compared. A methodological approach is presented, from early lab experimentation to As-free drinking water production, to evaluate As adsorbents´ capabilities. An adsorbent selection criterion is presented by employing three successive performance screenings: a backbone screening, followed by a spinoff screening and a final on-site screening. On-site studies recommendations for emerging BC projects for household-scale drinking water provisions were also made.