Preparation and phosphorus recovery performance of calcium silicate hydrate

Calcium silicate hydrate with phosphorus recovery efficiency was synthesized by carbide residue and silica.Effect of prepared method on phosphorus recovery efficiency of calcium silicate hydrate was studied.Mechanism of phosphorus recovery was revealed by XRD.Microstructure of calcium silicate hydrate was characterized by BET and SEM.Capacity of Ca2+ and OH-release was investigated.The considerable preparation conditions are obtained on the condition of Ca/Si molar ratio 1.6∶1,reaction temperature 170℃,reaction time 4.5h,stirring intensity 90r/min.Phosphorus content of product of phosphorus recovery reached 18.64.The prepared calcium silicate hydrate has a high BET surface area 113.3572m2/g with porous structure.Concentration of Ca2+ release reached 3.52mg/g.This material could recover phosphorus from wastewater in the form of hydroxyl calcium phosphate on the condition of pH=9.