Synthesis Of PANI/nZVI Catalysts For Catalytic Degradation Of Organic Pollutants In Aqueous Solution

The removal of non-biodegradable organic pollutants by nanoscale zero-valent irons(nZVI)/H2O/O2 oxidation system is considered to be an ideal and promising treatment technology due to the lower material cost, mild reaction conditions and non-toxic degradation products. Unfortunately, the system is difficult to give full play to its oxidation, because n ZVI are easy to agglomerate and its transfer ability are limited. In order to obtain efficient and stable nZVI, two kinds of PANI/nZVI composite catalysts are preparated considering the conductivity and catalytic properties of polyaniline(PANI). The promoting effect of anthraquinone-2-sulfonic acid(AQS) in the PANI/nZVI system is investigated. The main researches are concluded as follows:(1) The Polyaniline-supported nanoscale zero-valent iron(PANI/n ZVI) catalyst was synthesized and characterized using XRD、SEM 、EDX and FTIR. Effects of operating conditions on the degradation efficiency of RhB were investigated and the experimental results showed that the increase of the amount of catalyst, the decrease of the initial concentration were conductive to the degradation reactions. The optimal catalyst was PANI/n ZVI because of its high catalytic activity, good stability and unique recover nature.(2) The influence of AQS in the PANI/nZVI system was examined and the results indicated that the addition of AQS in PANI/n ZVI system increased the oxidation rate of RhB, which was ascribed to their role as an electron shuttle. The presence of AQS successfully increased the production of ?OH by building up the cycles of Fe(III)/Fe(II) and semiquinone/quinone.(3) The core-shell PANI/nZVI catalyst was synthesized and characterized by XRD and FTIR. The effects of the amount of catalyst, pH, the concentration of AQS and wastewater for the RhB degradation in the PANI/n ZVI system were studied. The results showed that acidic pH, the increase of the amount of catalyst, the decrease of the initial concentration were conductive to the degradation reactions. Furthermore, the proposed reaction mechanism responsible for the degradation process was identified by quenching studies.(4) The catalytic degradation abilities of PANI/n ZVI catalysts for secondary effluent were investigated by determining the CODCr in the system. The results showed that the catalytic degradation abilities of the synthesized catalysts for secondary effluent were excellent and the addition of AQS increased the oxidation rate.