Development And Application Of Heavy Metals In Waste Water Treatment Agent

Industrial wastewater containing heavy metal ions contaminates biotic environment greatly. Because heavy metal ions have a low-grade biodegradability, play along with food chain and be accumulated in living body at last, destruct living body's normal metabolism. Now the treatment of wastewater containing heavy metal ions has been paid great attention.In this article, basing on the existing study, the granular wastewater treatment agent which has blue-chip property for heavy metal ions contained wastewater prepared with modified natural apatites are rolled with the addition of water, in discs. During the formation, adhesive and foaming agent are use for improving the property of agent. The static and dynamic methods were used in the experiment of attenuating the heavy metal ions containing wastewater, and the invalid agent was treated to avoid secondary pollution.The results of preparation experiments of the wastewater treatment agent for heavy metal containing wastewater indicate that adding Al as adhesive and N-l as foaming agent are benefit for the property of the wastewater treatment agent. The optimum conditions to prepare wastewater treatment agent are: the fraction of -100 mesh of the modified natural apatites' particle size is 75%, clayl is 6%, N-l is 0.2%, moisture content is 10%, roasting temperature is 700 C and the retaining time is 20 minutes. Under the optimum condition, the removal ability of Pb2+ of the wastewater treatment agent can reach 661.10mg/g, have the decoloration and decline COD.Excellent attenuation of Pb 2+ is obtained at low pH, long conditioning time, high temperature and high initial concentration of heavy metal ions. To adapt the request of produce, the agent's size are required l-5mm. The specific surface area of hydroxyapatite mainly controls the removal ability of Pb2+ of the wastewater treatment agent. A TCLP test was conducted on the invalid agent. The centrifuged supernatant was found to contain 8.4mg/L Pb2+ which excess the national discharge standard, the exchanging ratio is 0.10%. After 3 hours of firing at 900 C, the concentration of Pb2+ is only 1.8mg/L, reach the national discharge standard. The compressive strength of brick manufacture with 10% of the invalid agent in brick clay get up to the national standard, the released concentration of Pb2+ is no other than 0.03mg/L, no secondary pollution.With the analysis of overall benefits, the wastewater treatment agent for heavy metal containing wastewater is a most potential environmental mineral material, which property is good and cost is cheap.