Rice Industry By-Products as Adsorbent Materials for Removing Fluoride and Arsenic from Drinking Water—A Review

In drinking water, high concentrations of fluoride and arsenic can have adverse effects on human health. Waste deriving from the rice industry (rice husk, straw, bran) be promising adsorbent materials, because they are (i) produced in large quantities many parts world, (ii) recoverable a circular economy perspective, (iii) at low cost if compared to expensive conventional activated carbon, (iv) easily manageable even developing countries. For removal fluoride, husk straw allowed obtain adsorption capacities range 7.9–15.2 mg/g. Using for adsorption, excellent results were achieved with above 19 The best both fluorides (>50 mg/g) found metal- or chemical-modified husk. Identifying next steps future research ensure upscaling biochar recovered by-products, it is fundamental perform: tests real waters multicomponent adsorption; experiments pilot plants continuous operation; analysis/real applicability modification treatments such as metal coupling chemical synthesis; more studies stability its regeneration recovery after use.