Home > Technology
Chemical precipitation is a widely used, proven technology for the removal and recovery of heavy metal from wastewaters. In this process, soluble heavy metal ions can be converted into relatively insoluble form through the addition of hydroxide compounds, sulfides or chelating agents. The settling process is often accelerated by the addition of coagulating/flocculating agents, which gather the insoluble metal compound particles into a coarse floc that can settle rapidly by gravity. Typically, the heavy metal content of wastewater can be reduced to some extent by precipitation and coagulation-flocculation mechanism. However, there are still significant residual heavy metals in wastewater that may no longer meet the increasingly stringent effluent discharge standards because the colloidal nature of metal precipitate makes the solid/liquid separation difficult. The current challenge for the disposal of such wastewater is the high basal heavy metal concentrations (e.g. typically 50 mg/L) after the initial treatment and to reach the regulatory discharge limits which are typically in sub-ppm levels is extremely costly.
Integration of Chelation and Flocculation Functionality in Polymer
An effective and environmentally friendly solution for treating heavy metals in effluents has been developed through integration of chelation and flocculation functionality in a single macromolecule. Copolymerization is used to modify the properties of macromolecules to improve the properties of chelation coagulation and flocculation.
pHSens Precipitation Technology
Most of the current heavy metal removal methods are often not economical and effective especially when the effluents contain a low concentration of heavy metals in the range of 1-50 mg/L. Most expensive treatment processes, e.g. ion exchange and membrane separation, have been used to meet the stringent effluent discharge standards reaching sub-ppm levels. Linovus PD series products are materials which will capture the heavy metals via the selective pH responsive precipitation during waste water treatment.