Arsenic contaminated water remediation: A state-of-the-art review in synchrony with sustainable development goals

Arsenic (As) is a highly abundant metalloid with detrimental effects on ecosystems and human health. Several research works have focused on the development and application of suitable materials capable of removing arsenic effectively from water. In this regard, nano-materials have been given considerable importance due to their unique properties. In addition to nano-materials, single, multi and doped metal oxides have also received substantial attention because of their high surface-to-volume ratio, increased magnetic properties, catalytic properties, etc. These metal oxides have been developed using several methods like solid state reaction, vapour deposition, chemical precipitation, etc. among which chemical precipitation is quite user friendly. Single and mixed metal oxides have been applied widely in arsenic removal since they usually have high arsenic adsorption capacity. Several biomaterials including biochar showed promising results in arsenic removal from water. Desorption studies showed that NaOH, KOH were effective in regenerating the adsorbents from the nano materials. Graphene based materials usually show very high surface area due to their open structure, thus, they are effective materials in arsenic removal from water. Water treatment using nanomaterials can be one of the sustainable solutions and in synchrony with Goal 6 in UN Sustainable Development Goals (SDGs), which aims to ensure availability and sustainable water management and sanitation for the global population. Nevertheless, there is a significant research gap between the application of these nano-materials in laboratory settings and their real-world field conditions. Additionally, only a limited number of studies have investigated the potential effects of these nanomaterials on the environment and living organisms. However, by carefully selecting appropriate materials and conducting thorough environmental risk assessments, we can overcome these challenges and move towards successful implementation of long term arsenic remediation.