Modeling photocatalytic degradation of diazinon from aqueous solutions and effluent toxicity risk assessment using Escherichia coli LMG 15862

Abstract

In this study, modeling and degradation of diazinon from contaminated water by advanced oxidation process together with a new test for effluent bioassay using E. coli were investigated. The experiments were designed based on response surface methodology. Nanoparticles (NPs) were synthesized using the sol–gel method. The shape characteristics and specifications of elements in the nanoparticles were characterized using scanning electron microscope and energy dispersive X-ray, respectively. Diazinon was measured using high performance liquid chromatography device and by-products due to its decomposition were identified by gas chromatography-mass (GC–MS). In the present study, effluent bioassay tests were conducted by defining the rate of dehydrogenase enzyme reducing alamar blue method. According to statistical analyses (R2 = 0.986), the optimized values for pH, dose of NPs, and contact time were found to be 6.75, 775 mg/L, and 65 min, respectively. At these conditions, 96.06% of the diazinon was removed. Four main by-products, diazoxon, 7-methyl-3-octyne, 2-isopropyl-6-methyl-4pyrimidinol and diethyl phosphonate were detected. According to the alamar blue reducing (ABR) test, 50% effective concentration, no observed effect concentration, and 100% effective concentration (EC100) for the mortality rate of E. coli were obtained as 2.275, 0.839, and 4.430 mg/L, respectively. Based on the results obtained, it was found that mentioned process was high efficiency in removing diazinon, and also a significant relationship between toxicity assessment tests were obtained (P < 0.05).

Impact of simulated microgravity on bioremoval of heavy-metals by Lactobacillus acidophilus ATCC 4356 from water

“…stated reversibility of binding indicating the significance of non-covalent electrostatic bonds (hydrogen and Van der Waals bonds) ( Zoghi et al., 2021 ). In another study, potential probiotic capacity against Cd toxicity was screened with 33 strains of lactic acid bacteria ( Toolabi et al., 2018 ). The results noted that Lactobacillus plantarum CCFM8610 showed significantly better binding ability and Cd tolerance than the other tested strains ( Zhai et al., 2015 ).…”

Advanced treatment of effluent extended aeration process using biological aerated filter (BAF) with natural media: modification in media, design and backwashing process

“…Also, ORP was reported at lower + 50 mV depth and, with the increase in the reactor floor height, ORP levels were increased as well. In aerobic processes due to increased dehydrogenase enzyme activity, ORP levels also increased, improving and facilitating organic material degradation (Toolabi et al 2017(Toolabi et al , 2018(Toolabi et al , 2019.…”

Advanced Treatment of Effluent Extended Aeration Process Using Biological Aerated Filter (BAF) With Natural Media: Modification in Media, Design, and Backwashing Process

“…Also, ORP was reported at lower +50 mV depth and, with the increase in the reactor oor height, ORP levels were increased as well. In aerobic processes due to increased dehydrogenase enzyme activity, ORP levels also increased, improving and facilitating organic material degradation (Toolabi et al, 2017, Toolabi et al, 2018, Toolabi et al, 2019).…”