[Removal of Lead Ions from Water by Struvite Natural Zeolite Composite].

ABSTRACT

A nitrogen and phosphorus recovery product (NZ-MAP) containing struvite was applied to remove heavy metal ions and lead from water. NZ-MAP was characterized using XRD, FTIR, and SEM/EDS. The effects of dosage, initial pH, and reaction time on the removal process were investigated. The results show that the main component of NZ-MAP is a natural zeolite loaded with struvite. When the dosage is 0.4 g·L-1, the maximum adsorption amount is 749.74 mg·g-1, and the adsorption of Pb2+ in the solution increases first and then tends to reach a balance with increase of the pH. Its removal mechanism is mainly Pb10 (PO4)6 (OH)2 precipitation, and the effect is best when pH is 5.0. The removal process of Pb2+ from water is more in line with the quasi-two stage kinetic model. In an investigation of the effect of coexisting heavy metal ions on the removal of lead ions in water by NZ-MAP, it was found that coexisting Ni2+ and Cu2+ have little effect on NZ-MAP adsorption on Pb2+. Coexisting Zn2+ and Al3+ obviously inhibit the adsorption of Pb2+ by NZ-MAP. The research shows that NZ-MAP material can remove lead ions from water efficiently, thus offering an effective method for doing this.