Effects from the concentration of coagulants and pH solution on the turbidity of the recirculating water used in the coffee cherry processingAiming the determination of the dose and pH range of the coagulants aluminum sulfate (AS), chlorinated ferrous sulfate (CFS), ferric chloride (FC) and Moringa oleifera seed extract (MSE) that would provide a higher efficiency in removing the turbidity from the coffee cherry pulping wastewater (CPW), five recirculations were accomplished and the coagulation/flocculation assays were conducted, by using the Jar-test device. The concentrations (0; 0.5; 1.0; 1.5; 2.0; 2.5 and 3.0 g L- 1) were evaluated. In the case of the MSE-prepared solution, the following doses were used: 0; 10; 20; 30; 40; 50 and 60 mL L-1. The pH of the solution under test was changed, by using the sodium hydroxide (NaOH) at the concentration of 0.3 mol L-1, whereas the ranges from 4.0 to 5.0; 5.0 to 6.0; 6.0 to 7.0; and 7.0 to 8.0 were evaluated. In the coagulation/flocculation assay, the MSE provided a higher suspended solid removal (SSR) from the CPW at the dose of 10 mL L-1 and 4.27 pH (natural). For the coagulants AS and FC, the best results were obtained at the concentration of 3 g L-1 and 7.27 pH, whereas, for the CFS coagulant, at the concentration of 3 g L-1 and 4.27 pH.
Moringa oleifera; wastewater; organic residue
