A novel triazine-based dithiocarbamate (DTC) was synthesized using cyanuric chloride, ethylenediamine and carbon disulfide as raw materials. The DTC product was characterized by Fourier Transform infrared spectroscopy (FTIR) and elemental analysis, and its performance in removing lead ions from water through chelating-type adsorption was evaluated. Characterization results demonstrate the successful synthesis of the target product DTC. The lead ion removing ratio was shown to increase with pH value (2–6), removing time (0 to 160 min) and adsorbent dosage (0–4 g L–1), and then keep almost unchanged when further increasing their values. However, the removing ratio was found to decrease with the increase of initial lead ion concentration. Meanwhile, the removal quantity decreased with adsorbent dosage and increased with initial lead ion concentration. The DTC product achieved 97.2% removing ratio under the condition of pH 6, removal time 160 min, adsorbent dosage 4 g L–1, and initial lead ion concentration 40 mg L–1. The relationship between removal quantity and equilibrium adsorption concentration showed a good fit with the Langmuir-type adsorption isotherm equation (R2 = 0.994) while a poor fit with the Freundlich equation (R2 = 0.961). This indicates that the lead ion adsorption on the prepared adsorbent corresponds to a monolayer coverage resulting from the chelating-type chemical adsorption on the DTC groups, namely the adsorption active sites. These results suggest the potential application of this novel DTC for removing heavy metals in the field of water treatment.
Xuefeng Li (Fri,) studied this question.