Synthesis Of A Hevy Capturing Agent And Its Wastewater Treatment Reseach

With development of the process of industrialization, heavy metal pollution has getting worse. But at the same time, it is difficult to meet the increasingly stringent emission requirements in using the traditional method to disposal of wastewater. As a result, reseach and development of a new type of high-efficient clean heavy metal wastewater has become a hot research field in treatment of wastewater containing heavy metals.This paper synthesized a kind of Dithiocarbamate capturing agent of heavy metals (DTC-SC) by using carbohydrazide (1,3-diaminourea), carbon disulfide and sodium hydroxide. The structure of the product was characterized by IR, Ultraviolet-visible and elementary analysis. According to the results, optimal synthesizing technology were as follows:4.5 g carbohydrazide,4.0 g sodium hydroxide and 12mL carbon disulfide (molar ratio for 1:4:2), reaction solvent was 50 mL inorganic solution and 30 mL organic solution (mixture of ethylene glycol and acetone with wolumetric proportion of 1:1), reaction temperature was 30℃ and equilibration time was 1 h, the conversion rate of DTC-SC was 85.17%.Studies the effect of removal on using DTC-SC to treat the wastewater containing Cu2+ Mn2+, Pb2+, Zn2+ and Cd2+ separatly. The best of them is Cu2+:when disposing of 5-50 mg·L Cu2+ solution, th DTC-SC dosage is 0.04 g, pH>4, reaction time is 10 min at normal temperatures and introduction of PAM in small amount, the removal rate of Cu2+ is more than 99.5%. The optimum condition of capturing the other heavy metal ions is:when initial concentration is 10-20 mg·L-1, dosage is 0.08 g, pH>7, reaction time is 10 min at normal temperatures and introduction of PAM in small amount. The wastewater solution of Cu2+, Mn2+, Pb2+, Zn2+ and Cd2+ is able to reach the integrated wastewater discharge standard (CB 8978-1996) after treatment of DTC-SC.In the other hand, DTC-SC for treating the mixed wastewater containing Cu2+, Mn2+ and Cd2+. DTC-SC dosage is 0.08 g, pH=6, reaction time is 10 min at normal temperatures and introduction, of PAM in small amount can make the concentration is reduced to less than the integrated wastewater discharge standard (CB 8978-1996) while the initial concetration is 20mg·L-1.The DTC-SC can effectivvely remove heavy metals wastewater in a variety of heavy metal ions, including the Cu2+ capture is the best.In addition, the effect of coexistence of a variety of heavy metal ions wastewater treatment is better than containing single heavy metal ion wastewater treatment. So in a real world application, it need comprehensive consideration wastewater quality condition. Furthermor, heavy metals precipitated solids must be handled properly to prevent the secondary pollution.