Removal of TSS, turbidity, colour, Zn(II) and Cu(II) from synthetic wastewater using FCC and FSC, generated from Groundwater Treatment Plant Sludge (GWTPS)

Groundwater Treatment Plant Sludge (GWTPS) which was collected from Chicha, Kelantan, Malaysia was found to contain 30% of Fe2O3. Ferric Chloride Coagulant (FCC) and Ferric Sulfate Coagulant (FSC) were generated through digestion of GWTPS with HCl and H2SO4, respectively. The effect of various dosages of GWTPS and volume of distilled water to generate the highest concentration of FCC and FSC was studied. Coagulation and flocculation study was conducted to observe the effectiveness of FCC and FSC in removing TSS, turbidity, colour, Zn(II) and Cu(II) from synthetic wastewater. Optimum production of FCC can be achieved at ratio of 10g (GWTPS): 20 mL (HCl): 100 mL (distilled water), while for FSC the optimum production ratio was obtained at 7g (GWTPS): 4 mL (H2SO4): 100 mL (distilled water). Approximately 2.9% (29126 mg/L) of FCC and 1.8% (18548 mg/L) of FSC were generated from GWTPS. It was observed that FCC was effective as a coagulant as almost 100%, 99% and 98% of TSS, turbidity and colour was removed from synthetic wastewater, respectively, when 23 mg/L (0.4 mL) dosage of FCC was used. As for FSC, approximately 100%, 98% and 97% of TSS, turbidity and colour was removed from synthetic wastewater, respectively, with only 22 mg/L (0.6 mL) dosage of FSC used. The optimum pH for FCC and FSC in removing Zn(II) and Cu(II) from synthetic wastewater was found to be pH 7 and pH 8, respectively. Approximately 23 mg/L (0.4 mL) dosage of FCC and 22 mg/L (0.6 mL) dosage of FSC was needed to give remarkably high removal of Zn(II) and Cu(II).