Process Design for Struvite Precipitation from Industrial Wastewater Stream: Special Design

A system has been designed in order to assess its efficiency in recovering phosphorous as struvite. The system consists of an equalizer, reactor, settler tank, dryer and packing unit and it was not seeded with previous struvite. A special cost effective concrete tank model coated with "Epoxy" inner surface was suggested. The overall tank volume of cylindrical body is (556.65) m(3). The reactor is fed with industrial fertilizer effluents rich with phosphorous and ammonia. Natural Bittern (MgCl. 6H(2)O) was added as source of low cost magnesium. A mass and Energy balance of belt conveyor dryer is studied using fan with electrical energy 15 W and drying rate 67 Kg/day. A model was Formulated and studied for the mixed effluent to optimize the struvite precipitation using experimental design methodology where, phosphorous removal efficiency reached 86% - 92 %. This results were verified experimentally 84.74% for model verification. Crystalline struvite is characterized by x-rays diffraction (XRD), scan electron microscope (SEM) and (EDX) for degree purity. An economic study proves it is an eco-friendly process.