Production of microcapsule biosorbent of functionalized Lycopodium Clavatum Sporopollenin (Sp-CPTS-AHP) and its application to Cr(III) ions

WOS:0008881506000133-(Chloropropyl)-trimethoxysilane (CPTS) was modified on Lycopodium Clavatum Sporopollenin microcapsules (Sp) with the aim of obtaining the Sp-CPTS compound. 2-amino-3-hydroxypyri-dine (AHP) was immobilized on Sp-CPTS and a microcapsule adsorbent surface (Sp-CPTS-AHP) was prepared. This surface was prepared to effectively remove Cr(III) in the solution. The surface of Sp-CPTS-AHP microcapsule biosorbent was successfully characterized by Fourier-transform infrared spectroscopy and scanning electron microscopy. Some experimental parameters (pH, contact time, amount of biosorbent, temperature and concentration) affecting the removal of Cr(III) were investigated. Adsorption isotherm models were utilized to explain the adsorption event on the microcapsule biosorbent. As a result of Cr(III) application with Sp-CPTS-AHP microcap-sule biosorbent, approximately 70% Cr(III) removal was obtained at pH 6. The ΔH° value calculated for the Cr(III) in the solution at temperatures between 25°C–50°C is 29.31 kJ mol–1 and the ΔS° value is 235.88 J mol–1 K–1. The mean adsorption energy for the Sp-CPTS-AHP microcapsule biosorbent was calculated as 0.893, 1.271, 1.549 and 2.744 kJ mol–1 for 298, 308, 319 and 328 K, in Cr(III) solution respectively. According to the parameters interpreted from the experimental data, the best Cr removal was attained at pH = 6.0, 0.03 g adsorbent, 298 K temperature, 30 mg L–1 initial concentration and 90 min contact time. The correlation coefficient (qe) calculated with the pseudo-second-order model is 14.993 mg g–1 and the correlation coefficient calculated with the pseudo-first-order model is 7.568 mg g–1. Langmuir maximum adsorption capacity (qm) is 17.668, 19.646, 20.704 and 21.929 mg g–1 for 298°C, 308°C, 318°C and 328°C, respectively. The newly synthesized microcapsule adsorbent surface has shown significant success in removing Cr(III) from the solution. Therefore, it can be recommended for the effective removal of heavy metals from water