Water pollutants removal by coated quartz sand

The presence of the major environmental pollutants in water exhibits a variety of harmful effects on living organisms in polluted ecosystems. Very often, apart from ubiquitous arsenic (As), organic compounds, iron, manganese, hydrogen sulfide, ammonia and similar pollutants may reach dramatically high levels in originally unpolluted waters caused by anthropogenic activities. Accordingly, a variety of treatment processes are used to remove the pollutants from waters. However, the cost of the treatment plays an important role in final choice of the process to be applied.

In an effort to overcome limitations, the aim of this research was a new approach to the development and production of water pollutants removal media. As a result, a cheap and effective sorbent based on natural minerals has been synthesized for the treatment of contaminated waters. The process includes chemical and subsequent thermal treatment of quartz sand with a magnesium carbonate water solution. The modified quartz sand was characterized and the material’s effectiveness in As, Fe and Mn removal from synthetic waters was tested. The MgO-coated sand in 5 min. interaction in column operation with 250 ml of synthetic water, with 200 µgL^-1 of As(III), 0.51 mgL^-1 of Fe(III) and 1.41 mgL^-1 of Mn(II), removed 90% of the As(III). The final concentrations of arsenic, iron and manganese in treated waters after ten minutes of contact with active materials were very close to zero. The MgO-coated sand exhibited a strong ability to remove both ionic and colloidal forms of pollutants from treated waters. The removal process is based on redox and sorption processes on the surface and inside the pores of active material.