Comparative study of adsorption for m‐phenylenediamine in aqueous solution onto chemically modified resins

Abstract

Four kinds of hypercrosslinked resins (acidic resins labeled SAMR and TAMR and heterocyclic resins IDLMR and PRLMR) were synthesized as adsorbents to remove m-phenylenediamine (MPD) from aqueous solution comparably. The Brunauer-Emmett-Teller specific surface area and pore size distribution of the two types of resins have been compared, and the infrared spectra of the resins confirm the presence of the modified groups. The adsorption isotherms illustrate that the Freundlich equation fits more appropriately than the Langmuir equation or the Temkin equation. In addition, the kinetic curves indicate that the pseudo-second-order model is a better fit than the pseudo-first-order model. The thermodynamic studies show that the isosteric adsorption enthalpy changes (ΔH) and the Gibbs free energy change (ΔG) are both negative, revealing that all of the adsorption processes are spontaneous and exothermic. All of the modified resins exhibit the best adsorption capacity at pH = 6.24. The results show that the acidic resins have better adsorption of MPD.

Removal of 3-Chloroaniline from aqueous solution by Treated Coffee Waste: Isotherm Modelling and Thermodynamic Studies

“…of value of ΔH° (-56.6 KJ mol -1 ) is near to hydrogen bonding range (8-50 KJ mol -1 ). Therefore, during the 544 sorption process hydrogen bond may also play a major role [83].…”

“…Several adsorbent materials have been utilized for the removal of amines from industrial effluents such as clay [28,37], carbon nanotubes [38] and activated carbon [39]. Also, resin [40,41] has many applications to treat and re-utilize waste water especially hyper-crosslinked resin which has a powerful ability for re-generation and high sorption's capacity [42][43][44]. The surface modifications, that can greatly improve the sorption selectivity, can develop custom-designed sorption resins with unique functional groups [3,[45][46][47][48].…”