Degradation of p-nitrophenol(PNP) in aqueous solution by mFe/Cu-air-PS system

In this study,batch experiments were conducted to investigate the performance of microscale Fe/Cu bimetallic particles-air-persulfate system(mFe/Cu-air-PS)for p-nitrophenol(PNP)treatment in aqueous solution.First,the optimal operating parameters(i.e.,aeration rate of 1.0 L/min,theoretical Cu mass loading(TMLCu)of 0.110 g Cu/g Fe,mFe/Cu dosage of 15 g/L,PS total dosage of 15 mmol/L,feeding times of PS of 5,initial pH 5.4)were obtained successively by single-factor experiments.Under the optimal conditions,high COD and TOC removal efficiencies(71.0%,65.8%)were obtained after 60 min treatment.Afterword,compared with control experiments(i.e.,mFe/Cu,air,PS,mFe/Cu-air,mFe/Cu–PS,air-PS and mFe-air-PS),mFe/Cu-air-PS system exerted superior performance for pollutants removal due to the synergistic effect between mFe/Cu,air and PS.In addition,the results of control experiments and radical quenching experiments indicate this reinforcement by feeding of PS was greater than by aeration in m Fe/Cu-air-PS system.Furthermore,the degradation intermediates of PNP in mFe/Cu-air-PS process were identified and measured by HPLC.Based on the detected intermediates,the degradation pathways of PNP were proposed comprehensively,which revealed that toxic and refractory PNP in aqueous solution could be decomposed effectively and transformed into lower toxicity intermediates.As a result,m Fe/Cu-air-PS system with the performance of oxidation combined reduction can be also a potential technology for the treatment of toxic and refractory PNP contained wastewater.

Efficient reduction of hexavalent chromium with microscale Fe/Cu bimetals:Efficiency and the role of Cu

Microscale zero valent iron(mFe^(0))is one of the most potential water pollution remediation materials,but the effective utilization ability of electrons released by mFe^(0)in the reduction of hexavalent chromium(Cr(VI))is not satisfactory.Here,we find the microscale iron-copper(m Fe/Cu)bimetals coated with copper on the surface of mFe^(0)can significantly improve the effective utilization of electrons released by mFe^(0).Electrochemical analysis displays that copper plating on the surface of m Fe/Cu can promote the release the electrons from mFe^(0)and reduce the impedance of mFe^(0).Spin-polarized density functional theory(DFT)calculation reveals that Cu on the surface of m Fe/Cu bimetals promotes the release of electrons from mFe^(0)and reduces the adsorption energy of Fe to Cr.As the electron transporter,moreover,Cu can always attract Cr to the hollow position near itself of the Fe surface,which could promote the effective utilization of electrons released by Fe.Effective utilization ability of electrons in m Fe/Cu system is 12.5 times higher than that in mFe^(0)system.Our findings provide another basis for the efficient reduction of Cr(VI)by m Fe/Cu bimetals,which could promote the application and popularization of m Fe/Cu bimetals.

金堆城钼矿体深部综合利用之思考

根据金堆城钼矿体深部两种不同类型矿石量的变化及Ｃｕ、ＭＦｅ 在矿区的分布规律，详细分析了不同平盘Ｃｕ，ＭＦｅ 的品位变化，对综合回收有一定的指导意义。