Modeling and Optimization of Removal of Cefalexin From Aquatic Solutions by Enzymatic Oxidation Using Experimental Design

Abstract

Antibiotics are used globally and, after use, they enter water sources in different ways. The presence of these compounds in the environment has created concerns about the toxicity of aquatic organisms and the emergence of antibiotic-resistant bacteria. The purpose of this study was to remove cefalexin from aqueous solutions by enzymatic oxidation using response surface methodology (RSM). For this purpose, batch experiments were performed to evaluate the effect of independent variables, including temperature, pH, contact time, enzyme activity, HBT mediator concentration, and antibiotic concentration. The residual cefalexin concentration was determined by HPLC. The Box-Behnken design of experiments and RSM were used to evaluate the overlap between variables. The results showed that the oxidation efficiency increased with increasing contact time and enzyme activity and decreasing antibiotic concentration. The highest and lowest removal percentages were 90.5% and 5.54%, respectively. Considering the value of R 2 (0.946) and adjusted R 2 (0.95) in the RSM model, one can state that the selected model is suitable for data analysis. Finally, the second-order polynomial analysis and the quadratic model were used as the best model for finding the relationship between the main variables and cefalexin removal efficiency. The Box-Behnken Design model can be effective for optimizing enzymatic oxidation of cefalexin, and laccase can be used to remove cefalexin.

Evaluation and Optimization of Antibiotics Resistance Profile against Clostridium perfringens from Buffalo and Cattle in Pakistan

“…Optimization of antibiotics application to bacterial isolates was performed under the Box–Behnken design (BBD) via response surface methodology (RSM), which confirms that ciprofloxacin and ampicillin showed maximum inhibition either applied as a single treatment or in combination, while cefotaxime used at lower concentration proved beneficial, and the isolated growth was very less which confirmed that judicious and appropriate application is helpful to combat the antibiotic resistance in bacteria. These results show resemblance with Shokoohi et al (2018) in which they confirmed that antibiotics can also be checked against a particular pathogen using optimization via response surface methodology, and this method gave appreciable results [ 6 ]. El-Naggar et al (2013) also described that Gram-positive and Gram-negative bacteria can be effectively inhibited by prevalent antibiotics; furthermore, the antibiotic resistance was greatly due to the application of multiple drugs available worldwide [ 3 ].…”

“…These resistomes are mainly evolved from hospitals, pharmaceutical companies, and livestock producers’ unmonitored waste that contains antimicrobial substances that have been circulating in our environment. Among all pathogens, Staphylococcus spp., Campylobacter spp., Enterococcus spp., Salmonella spp., and Extended Spectrum Beta-Lactamase (ESBL) producing Enterobacteriaceae are most commonly found in the environment [ 6 , 7 ].…”

Green synthesis of zinc oxide nanoparticles loaded on activated carbon prepared from walnut peel extract for the removal of Eosin Y and Erythrosine B dyes from aqueous solution: experimental approaches, kinetics models, and thermodynamic studies

“…The initial and final Eo-Y and Er-B concentrations remaining in solutions were examined by a DR5000 spectrophotometer (Shimadzu Model: HACH®), USA at a wavelength of maximum absorbance, λmax = and nm, respectively. The removal efficiency, R (%) and the amount of Eo-Y and Er-B adsorbed, qe (mg/g) of the studied parameters were calculated based on the following formulas (Rashtbari et al 2018, Shokoohi et al 2018…”

Removal of metronidazole antibiotic from aqueous solution by ammonia-modified activated carbon: adsorption isotherm and kinetic study

“…Although the environmental concentration of antibiotics is very low, they can threaten human health due to bacterial resistance. Studies have shown that antibiotics are absorbed in small amounts in the body, and most of which are excreted from the body (Shemer et al 2006;Shokoohi et al 2018a).…”