Enhanced catalytic activity of series LaCuxFe1-xO3 (x = 0.2, 0.4, 0.6, 0.8) perovskite-like catalyst for the treatment of highly toxic ABS resin wastewater: Phytotoxicity study, parameter optimization and reaction pathways

Abstract

In the present study, acrylonitrile butadiene styrene (ABS) resin wastewater was treated by series LaCuxFe1-xO3 (x = 0.2, 0.4, 0.6, 0.8) perovskite-like catalyst activated with peroxymonosulfate (PMS). The catalyst was synthesized by solgel method and further characterized by various techniques including i.e., XRD, FTIR, BET, FE-SEM with EDAX, TEM and XPS. Phytotoxicity study was performed to assess the toxicity of ABS resin wastewater on common agriculture crops viz., Vigna radiatus L. (Mung) and Hordeum vulgare L.(Barley). The effect of various parameters e.g., catalyst dosage (250−1050 mg/L), PMS dosage (1−5 mM), pH (2−10) and temperature (30−90 °C) were evaluated and optimize the parameters through central composite design (CCD) in response surface methodology (RSM). The maximum removal of acrylonitrile and TOC were observed 94.06 % and 66.70 %, respectively at optimum operating conditions obtained from RSM tools. The kinetic studies for the degradation of acrylonitrile and TOC was performed by two step pseudo first order kinetic model at various temperatures (30−90 °C). Catalyst reusability and chemical stability study were analyzed and degradation of acrylonitrile i.e., 94.06 %, 91.38 %, 88.42 % and 86.92 %; and TOC i.e., 66.70 %, 64.35 %, 61.59 % and 59.21 % were observed in first, second, third and fourth consecutive cycles. The proposed reaction pathways and PMS activation mechanism were investigated based on intermediate detected from GC–MS analysis and scavenger experimental study. Operating cost of treatment of ABS resin wastewater was estimated to be 75.60$/m3 wastewater.