Evaluating the possibility of color treatment of Tarcon Blue 2BLN dye by coagulating materials PGa21Ca, polyaluminium chloride, iron (II) sulfate heptahydrate and aluminium sulfate octadecahydrate

Abstract

This article presented the results of color treament ability of Tarcon Blue 2BLN dye with some flocculation chemicals such as PGa21Ca, polyaluminium chloride (PAC), iron (II) sulfate heptahydrate (FeSO4.7H2O) and aluminium sulfate octadecahydrate (Al2(SO4)3.18H2O). Our results showed that conditions for treatment the color to reach column B, QCVN 13: 2015 / BTNMT (national technical regulation on textile and dying industry) by different flocculation chemicals were the same exposure time (10 minutes), sedimentation time (30 minutes), but different in parameters of concentration (% mass), stirring speed and pH. Specifically: PGa21Ca (0.02%), PAC (0.01%), aluminium sulfate octadecahydrate (0.003%) can handle color at the initial pH of the solution (pH = 6), with the stirring speed corresponding to each flocculation chemical at 120 rpm, 45 rpm and 45 rpm respectively. In contrast, with iron (II) sulfate heptahydrate (0.02%), only the color treatment reaches column B, QCVN 13: 2015 / BTNMT when the pH of the wastewater raises to 10 and stirring speed is 120 rpm. Compared with PAC, aluminium sulfate octadecahydrate and iron (II) sulfate heptahydrate, PGa21Ca has the advantage of contributing to raise the pH value in the acid solution, which reduces the pH in the base environment, and not changing the pH when the concentration of PGa21Ca increases. Test results on actual wastewater samples taken from Hoa Khanh Danang Textile Joint Stock Company (DANATEX) showed that the ability of treating color of these chemicals on actual wastewater samples is lower than the ability on water samples blended with Tarcon Blue 2BLN dye.