Enhanced removal of p-chloroaniline from aqueous solution by a carboxylated polymeric sorbent

In the present study a carboxylated styrene-divinylbenzene (St-DVB) polymeric sorbent (CSPS) was prepared for enhanced removal of p-chloroaniline from aqueous solution. A commercial styrene-divinylbenzene polymeric sorbent Amberlite XAD-4 was selected as the reference sorbent to evaluate the performance of CSPS. Characterization of CSPS was determined by infrared spectroscopy and pore size distribution. A p-chloroaniline sorption enhancement on CSPS at capacity about twice of Amberlite XAD-4 was observed, which was mainly attributed to the carboxyl group added on the polymeric matrix. Different pH-dependent sorption property of p-chloroaniline onto XAD-4 and CSPS was observed partly due to the role of carboxyl group. Sorption isotherm of p-chloroaniline on CSPS could be represented by Freundlich model reasonably, and that on XAD-4 was more suitable for Langmuir model. Kinetic studies demonstrated that the uptake of p-chloroaniline on CSPS and XAD-4 followed the pseudo-second order model. Moreover, breakthrough curves on CSPS further demonstrated its better performance towards p-chloroaniline removal from aqueous solution. Complete regeneration of the spent sorbent CSPS was achieved by dilute hydrochloric acid for its repeated use, implying its potential application in associated chemical wastewater treatments.