Use of Carica papaya waste as bio-adsorbent for sewage wastewater treatment

Abstract

A large amount of wastewater is generated, with the rapid increase in the human population, industrialization, and agricultural development, that leads to a decrease in freshwater amount at an alarming rate. Hence, the current research aims to investigate the effect of the mark of natural bio-sorbent on the improvement of the physicochemical properties of sewage wastewater. The obtained powder was characterized by a Fourier transmission infrared spectrophotometer (FTIR), field emission scanning electron microscopy (SEM), dynamic light scattering (DLS), X-ray diffractometer (XRD), X-ray fluorescence (XRF), Brunauer–Emmett–Teller (BET), and zeta potential. The batch adsorption process was carried out to study the effect of adsorbent dose (0.25–1.5 g/mL) and contact time (0–180 min) at a constant temperature of 23 ± 2 °C and a stirring speed of 150 rpm. After treatment with the obtained powder, the physicochemical properties of wastewater were significantly improved, and 77, 79.2, 95, 37.4, 50, and 38.1% reductions of COD, BOD, TSS, TDS, TN, and TP were reached, respectively, at an adsorbent dose of 0.5 g/500 mL and contact time of 180 min. The adsorption equilibrium data were examined, and the adsorption data was well represented by the Langmuir isotherm model, and the most appropriate kinetic model was pseudo-second order. The current research proves that Carica papaya seeds are considered a potential recyclable adsorbent to improve the physicochemical properties of wastewater.