Microbial mediated synthesis of lanthanum-modified seed crystals and their application for removal of phosphorus and calcium from domestic wastewater

Abstract

In this study, lanthanum was introduced into the microbially induced calcium precipitation by bio-mediated action of Pseudomonas aeruginosa to synthesize modified seed crystals for the removal of calcium and phosphorus from domestic wastewater. The calcium and phosphorus removal efficiency reached to 60% and 94%, respectively, under the condition of 30 times repeated use. Meanwhile, chemisorption and intra-particle diffusion were identified as the main rate-limiting steps and electrostatic interaction, ligand exchange, and induced crystallization as the primary phosphorus removal mechanisms. This modified seed crystal exhibited better phosphorus removal performance in simulated reactors with different water quality parameters (phosphorus removal efficiency of 95%). This safe, stable, and efficient bio-material has a promising future in the current socio-economic condition of energy shortage and environmental pollution.