Creation of Nanomagnetite Aggregated Iron Oxide Hydroxide for Magnetically Removal of Fluoride and Phosphate from Wastewater

Abstract

A new chemical adsorbent for fluoride and phosphate removals was produced by applying a novel nanomagnetite aggregation process through the formation procedure of an iron oxide hydroxide, i.e., schwertmannite. Although there was no evidence of magnetite related peaks in the XRD pattern of the new adsorbent, because of the very small amount of the used magnetite particles, the SEM picture reveals a surface alteration on the crystal structure of the new adsorbent comparing to the schwertmannite. The results of magnetic removal of fluoride and phosphate using the new adsorbent indicate that nanomagnetite aggregation process not only improves the magnetic property, but also provides a highly-promoted fluoride and phosphate adsorption capacities comparing to the schwertmannite.KEY WORDS: fluoride removal; phosphate removal; magnetic filter; wastewater treatment; schwertmannite; nanomagnetite; electromagnetic processing of materials.

Control of nonmagnetic particles using a magnetic field

“…The extremely fine particles and the mud-like properties of the adsorbent cause a variety of problems in the application of ordinary packed beds such as a large drop in pressure. Figures 1 and 2 show a small-scale physical model of the proposed process wherein schwertmannite powder was packed in a glass column with ferromagnetic wool layers alternately laid among the adsorbent layers [3]. 1 g schwertmannite or 0.4 g iron wool was placed in each layer.…”

Removal of phosphate and fluoride from wastewater by a hybrid precipitation–microfiltration process

“…Fluoride and phosphate can be simultaneously removed by a novel nanomagnetite aggregation process [5]. Cement paste has been used to remove fluoride and phosphate from semiconductor wastewater through precipitation and adsorption [3].…”

“…High concentration of fluoride is found among some industrial wastewater and its removal has been extensively studied using various technologies, such as adsorption [8,9], electrocoagulation [10], and precipitation [11]. Precipitates of calcium phosphate and calcium fluoride are usually very fine and coagulation-flocculation is needed for solid separation [2,5,11].…”

Simultaneous removal of nitrate, phosphate, and fluoride using a ZVI-packed bed electrolytic cell

“…As the most wellknown methods for phosphate removal, adsorption methods are promising since they allow simple and economical operations resulting in less sludge production and fewer disposal problems. In phosphate treatment in wastewater, the removal method to precipitate phosphate involves the application of dissolved cations, such as Al 3+ , Ca 2+ , Fe 3+ , and Fe 2+ [12].…”