Fluoride removal from water by a novel dodonaea viscosa bark biochar adsorbent

An excess of the fluoride ion (F-) above the recommended upper limit, such as the WHO recommended upper limit of 1.5 mgL(-1), may cause fluorosis in humans, as reported in several countries, e.g. Pakistan, China, and India. Various commercial adsorbents has been used for F- removal from water but there is still a desire for an environmentally friendly and economic adsorbent. Therefore, a novel adsorbent, i.e. Dodonaea bark biochar (DBBC) was prepared, from Dodonaea viscosa under pyrolysis at 750 ? in an inert atmosphere, to remove excessive F- from water and studied with batch experiments involving a number of parameters: pH (2-10), contact-time (5-145 minutes), dosage of adsorbent (1-7 g/50 mL), and initial F- concentration (2-10 mgL(-1)). The biochar showed 90% F- removal in the acidic range and 60% removal at neutral pH under optimized conditions. In conclusion, the adsorbent DBBC is recommended as an inexpensive sorbent material for F- contaminated water.