Performance Study of Watermelon Rind as Coagulants for the Wastewater Treatment

Abstract

The scarcity of fresh and hygienic water sources leads to a demand of more research for the treatment of wastewater. One of the possible ways is using a watermelon rind as a natural coagulant where its performance was investigated in terms of turbidity, pH and BOD. Watermelon rind (WR) and alum(A) at different compositions (WR100, WR50A50, WR70A30, A100) were introduced in the synthetic wastewater before treated on natural wastewater by jar test. Results revealed that the turbidity, pH as well as dissolved oxygen level were highly dependent on the coagulant dosage. About 90% of turbidity was reducing at 70% of powdered watermelon rind and 30% alum (WR70A30) on the contrary only 72% in natural wastewater. In addition, WR70A30 had better reduction in turbidity as compared to using 100A. On the other hand, final pH reading falls approximately in the range of 6 to 8, respectively which is acceptable for the standard wastewater discharge. Meanwhile, the results for the BOD5 for the natural wastewater is in the ranges between 0.35 to 1.39 had met the WHO standard. Finally, the FTIR analysis on treated and untreated watermelon rind confirms similar peaks of functional groups. Overall, the present study on WR as coagulant show a good performance in treating both natural and synthetic wastewater.

Optimization use of watermelon rind in the coagulation-flocculation process by Box Behnken design for copper, zinc, and turbidity removal

“…Another peak around 1634 cm −1 relates to carboxylic acid C O stretching. Furthermore, the 1380 cm −1 peak is attributed to symmetric –COO– stretching of pectin groups [ 28 ]. FTIR analysis demonstrates WMR contains various functional groups like NH, COOH, C O, and –COO–, which could serve as potential adsorption sites for metal ions.…”

“…The rinds were washed with distilled water to eliminate all impurities. After washing, the rinds were oven-dried at 105 °C for 24 h, then ground and sieved to achieve powders with diameters of 60, 90, and 120 μm for use as a bio-coagulant [ 28 ]. The WMR obtained was directly utilized for the coagulation tests without chemical treatment.…”

“…For that we have choose to study the effectiveness of fruit peels like watermelon rind (WMR) as a bio-coagulant for the removal of metals and turbidity by the coagulation-flocculation process. In fact, WMR is abandoning, presenting a high adsorption capacity for metals and little studied as a coagulant [ 28 ]. Watermelon “Citrullus lanatus” is a globally cultivated fruit known for its high water content, and low calorie count [ 29 ].…”