Effects Of Phosphate On The Adsorption Of Cu、cd In Bioretention Media

In this article the uniform design method was applied to examine the solutions whith three different concentrations of heavy metals under the conditions of the matrix materials, pH, potassium hydrogen phosphate on the effects of the copper and cadmium adsorption by simulating biological stranded device for determination of the effect of the removal of heavy metal cadmium, and the heavy metal contents in the soil after leaching were determined. Finally the chemical equilibrium model of Visual MINTEQ Cu-Cd-KH2PO4 system have been uses to analyze the chemical reaction and precipitation generated. The results showed that:Soil content and phosphate on adsorption of heavy metals have been promoted; pH has a great influence on copper and cadmium adsorption rate and pH in the range of 6 to 8, copper and cadmium can achieve the best effect of precipitation, phosphate could significantly increase the heavy metal removal rate; When the pH > 10, phosphate increase did not increase the precipitation effect of copper and cadmium, but generated hydroxyl yes copper and cadmium still had better removal rateBiological stranded facilities simulation of copper cadmium rain had a good removal effect. Phosphate can increase with the adsorption of heavy metals on soil effect and adsorption capacity, most of the radial distribution of heavy metals in soil heavy metal on the surface of 20 cm is fixed, phosphate have promote role. Potassium hydrogen phosphate using lead to increasing the concentration of phosphorus in water, showed the biological stranded facilities to soluble phosphate removal the effect not beautiful.Model data showed that phosphate with copper ions generated by the sediment peaked within the range of pH 6-8, in acidic conditions without generating, eutectic transformation to generate copper hydroxide in alkaline conditions; But under acid condition cadmium ion and phosphate precipitation almost nothing generated, neutrally the phosphate deposits formed gradually, the alkaline range of pH value is 8 to 12 which can achieve maximum precipitation effect and have relatively stable chemical properties, not easy to be decompose.