Modified amorphous silica from a geothermal central as a metal adsorption agent for the regeneration of wastewater

A wastewater regeneration treatment was successfully designed by using modified amorphous silica as an adsorption agent, this ceramic material is generated as an industrial waste in a geothermal power plant located in the City of Mexicali, Baja California. A tertiary wastewater process for the removal of heavy metals from wastewater was designed by modifying purified amorphous silica (99.40% by weight) with low cost reagents as urea and sodium carbonate in a sol – gel reaction. The wastewater treatment with the urea modification allowed to eliminate 40% of chromium and zinc, 70% of nickel, 60% of copper and 90% of lead; while the carbonate modification allowed to remove 30% of nickel, 70 – 80% of chromium and copper and over 90% of aluminum and zinc; achieving a good effluent quality with optimal chemical-physical conditions for its re -use.