Simultaneous sorption of phosphate and phenanthrene to inorgano–organo-bentonite from water

The nonbiodegradable organic pollutants and excess phosphate can not be effectively removed from municipal wastewater by the widely used bioprocess, thus they are harmful to aquatic environment. In this investigation, the feasibility of utilizing inorgano–organo-bentonite (IOB), which was bentonite mineral modified with both Fe polycations and cetyltrimethylammonium bromide (CTMAB), was explored to simultaneously remove phosphate and phenanthrene from water. The results showed that the IOB had strong affinity for both phosphate and polycyclic aromatic hydrocarbons (PAHs) such as phenanthrene in water. It was found that more than 95% phosphate and 99% phenanthrene were removed from water within 30 min. The sorption of phosphate on IOB proved to be an anion/OH− exchange reaction. Compared with organobentonite and bentonite mineral, the settlement separation of IOB from aquatic phase was greatly improved. The residual turbidity reached a minimum value of 10 nephelometric turbidity units (NTU) in 60 min. It was indicated that IOB is a favorable sorbent and can simultaneously remove nonbiodegradable organic pollutants such as phenanthrene and phosphate after the bioprocess in wastewater treatment.