Comparison of polyferric chloride and polytitanium chloride in removal of organic and inorganic pollutants from young and old municipal solid waste leachate

Abstract

The present study compared the polytitanium chloride (PTC) and polyferric chloride (PFC) in removal of Pollutants from young and old solid waste leachate. Moreover, synthesis of PTC and PFC coagulants, field emission scanning electron microscopy (FESEM) images, energy-dispersive X-ray spectroscopy (EDX) analysis, Fourier transform infrared spectroscopy (FTIR) analysis of PTC and PFC coagulants and flocs characteristics were examined. At optimal coagulant doses (250 mg/L for PTC and 400 mg/L for PFC), PTC removal efficiencies in old leachate for COD, readily biodegradable COD (rbCOD), color, TSS, turbidity, and total Kjeldahl nitrogen (TKN) were 91.30%, 92.94%, 99.80%, 98.06%, 99.76%, and 98%, respectively and for PFC were 81.15%, 81.17%, 94.23%, 90.32%, 96.09%, and 94.28%, respectively. PTC removal efficiencies in young leachate for COD, rbCOD, color, TSS, turbidity, and TKN, were 71.08%, 80.30%, 70.45%, 83.07%, 88%, and 88.57%, respectively, and for PFC were 65.06%, 71.21%, 61.36%, 80.76%, 84%, and 83%, respectively. According to FESEM-EDX analysis, flocs resulting from PTC coagulant were larger in size and more compacted in structure compared to PFC flocs. The results of this study indicated that PTC had a higher efficiency than PFC; therefore, it can be used as a suitable option for solid waste leachate treatment, especially old leachate.