Evaluating the possibility of the dyeing wastewater treatment using the coagulating material PGα21Ca and aluminium sulfate

Abstract

PGα21Ca is a natural polymer polymerized from polygamma glutamic acid. It is non-toxic, biodegradable, and widely used in the field of textile wastewater treatment in Japan and some other developed countries; however, it has not yet been used in Vietnam. This paper presents the research results of a survey on the current dyeing wastewater treatment quality in terms of colourants, pH, organic compounds in dyeing wastewater by using a new coagulating material PGα21Ca and aluminium sulfate (Al2 (SO4 )3 .18H2 O). The experimental results showed that the colour and COD removal efficiency of PGα21Ca is higher than aluminium sulfate - Al₂ (SO₄ )₃ .18H₂ O. For PGα21Ca, the color removal efficiency was 95%, and the COD removal efficiency was 35%. For aluminium sulfate, the color removal efficiency was 86%, and the COD removal efficiency was 13%. In addition, PGα21Ca was also capable of bringing the pH value of the wastewater to the pH value of neutral medium. On that basis, this article also showed the successful operation of the automation treatment model for textile dyeing wastewater using PGα21Ca, ensuring the colour of textile dyeing wastewater after the treatment to reach the National Technical Regulation on the effluent of textile industry (QCVN 13:2015/BTNMT).