Enhanced removing of phosphate ions from agricultural drainage wastewater by using microwave-assisted synthesized attapulgite (Fullers earth) @carboxymethylcellulose nanocomposite

Abstract

Contamination of various water resources with phosphate pollutant owing to the excessive use of phosphate fertilizers was labeled by dangerous consequences. Most of the water remediation methods are not efficient for phosphate recovery and always generate secondary wastes. Therefore, the current study is aimed to prepare a novel ecofriendly and sustainable APT500@CMC nanocomposite via simple covalent binding of thermally treated attapulgite clay at 500 °C (APT500) with carboxymethyl cellulose (CMC) using microwave irradiation process. The assembled nanocomposite was confirmed by diverse techniques. The optimum conditions for efficient 10, 25 and 50 mg/L PO43− removal were detected at pH 3, time 30 min, temperature 25 °C and mass 200 mg. The kinetic and isotherms were fitted both to a combination of pseudo 1st - 2nd orders and Langmuir model, while thermodynamic parameters verified PO43− removal via spontaneous and exothermic reaction behavior. The mode of interaction and binding of PO43− ions onto the surface of APT500@CMC were suggested via ion-pair interaction process. Excellent PO43− recovery (98.8 %) from real agricultural drainage wastewater was established. The explored APT500@CMC afforded good stability for five regeneration cycles. Therefore, the collected results confirm the validity of APT500@CMC for excellent removal of PO43− from real agricultural drainage wastewater.