Removal of arsenic from dilute solutions using steric reticular poly(N¹,N¹,N³,N³-tetraallylpropane-1,3-diaminium chloride)

The high health hazard of arsenic-contaminated drinking water caused authorities worldwide to change the maximum permissible limit for arsenic (As) from 50 to 10 μg/L. Therefore, novel techniques and materials for their removal from aqueous streams must be developed. In the current study, a novel polymer, poly(N¹,N¹,N³,N³-tetraallylpropane-1,3-diaminium chloride) (PTAPDAC), was synthesized and its performance characteristics in the removal of As from dilute solutions were examined. PTAPDAC is a brittle solid with a steric reticular structure. It is insoluble in water and common organic solvents and has a positive charge at every other three or six –CH₂– (or –CH–) unit. The polymer could optimally absorb As at pH 6.0–7.5, with the peak uptake at ∼6.9. When used in a continuous treatment process for the treatment of shallow groundwater containing 0.73 mg/L As, PTAPDAC could treat groundwater 93,333.3 times its weight. The adsorption capacity for As was ∼67.2 mg/g, and the As removal rate reached 98.63%.