Performance evaluation and optimization of the treatment of dye laden wastewater using alum and Luffa cylindrica seed extract as coagulant

Abstract

AbstractThe treatment of dye laden wastewater (DLW) was investigated using alum, and Luffa cylindrica seed extract, . Cibacron green dye and distilled water were used to simulate the DLW in the laboratory. The optimum conditions for the removal of color and chemical oxygen demand (COD) from DLW was determined using both regular and response surface methodology, RSM‐Jar tests with coagulant dosage, DLW pH, stirring time, and temperature as the independent variables. Instrumental characterization of the coagulant and produced sludge were studied. Individual effect using regular Jar test, and had best color removal efficiency of 98.4% (2 g/L, pH 8, 30 min and 55°C), and 97.7% (5 g/L, pH 2, 20 min and 55°C), respectively. Also, for COD removal efficiency, and had 85.6% (2 g/L, pH 10 and 30 min), and 88.1% (4 g/L, pH 4 and 30 min), respectively. Applying RSM‐Jar test, 99.6% and 88.7% color and COD removal efficiency were achieved with 4 g/L , 0.25 g/L , pH 8, and 40°C and 5 g/L , 0.40 g/L , pH 6, and 40°C, respectively. The results indicated that the combination of both coagulants () performed maximally with highly reduced alum dosage, exposing the novelty of the work. Hence, the novelty of the work is the use of minimal quantity of alum and Luffa cylindrica seed extract for effective removal color and COD from the DLW.