Greenhouse tomato plant roots/carboxymethyl cellulose method for the efficient removal and recovery of inorganic phosphate from agricultural wastewater

Phosphate (P) is a biologically important compound that is commonly incorporated into fertilizers. Wastewater from agricultural processes results in excessive accumulation of P and eutrophication of lakes. We have developed a system for the remediation, recovery, and potential reuse of P from agricultural wastewater using tomato plant roots (roots) as a capture matrix and carboxymethyl cellulose (CMC) as an eluent and enhancer of P precipitation. Untreated roots can bind up to 55.2 ± 15.2 grams of P per kilogram (g/kg) of roots in comparison to the maximum 8.2 ± 1.5 g/kg bound by the previously used iron-chitosan (Fe-chito). The addition of CMC enhances the precipitation of P with a clearance of 97.2% as opposed to 33.3% without CMC. On site tests show an average removal of 226.5 μg/L per day or a total of ∼28 g of P removed after 23 days. This corresponds to a 71% P removal rate.