Synthesis and application of wetland plant-based functional materials for aqueous antibiotics removal

In situ electrochemical generated metal hydroxides as coagulants for optimization of sulfamethoxazole removal

In this study, the antibiotic sulfamethoxazole (SMX) removal was investigated and optimized using the electrocoagulation process (ECP). The effective parameters including initial SMX concentration, current density, solution pH, reaction time, type and concentration of supporting electrolytes, and types of electrodes (Fe/Fe, Al/Al, Cu/Cu, and Zn/Zn), on the treatment process were investigated. Response surface methodology (RSM) applied for designing the study based on central composite design (CCD). The maximum treatment efficiency and energy consumption of 99.9% and 0.743 kWh m-3, respectively, was found in the optimum process condition including initial SMX concentration of 20 mg L-1, current density of 15.0 mA cm-2, solution pH of 9.0, reaction time of 17.0 min, 20 mM of NaCl as supporting electrolyte using Fe/Fe electrode. The statistical data including p-value of < 0.0001, F-value of 311.2, high determination coefficient (R2) of 0.9878, adjusted R2 of 0.9847, and predicted R2 of 0.9753 were revealed satisfactory correlation between the predicted values and experimental findings for the developed model. The ECP involves a combination of multiple mechanisms such as coagulation, flocculation, flotation, sedimentation, and adsorption that act synergistically to remove contaminants by applying electrical current.

Process and mechanism modeling of cefotaxime removal from hospital wastewater using pistachio shells based magnetic activated carbon nanoparticles

Antibiotic residues have been extensively identified in diverse aquatic environments, posing significant health risks to both humans and animals, while also presenting challenges to the environment. Consequently, the imperative need to effectively removal antibiotics from the environment has become a very importance issue. In this study, response surface methodology with central composite design was employed to systematically investigate the effects of key process parameters, on the removal of cefotaxime (CTX) from hospital wastewater using pistachio sells based activated carbon modified with FeCl3. The modified activated carbon was synthesized using a thermochemical method and characterized by analytical techniques including FE-SEM, FTIR, XRD, pHpzc, and BET analysis, which demonstrated its remarkable physicochemical properties. Maximum removal efficiency of 99.1% was obtained via the optimal values of 45 mg L- 1 of initial CTX concentration, solution pH 7, and 200 mg L- 1 of Fe@ACP dosage, 56 min of reaction time through adsorption process. According to the results, the non-linear Langmuir isotherm model (R2 = 0.9931) and non-linear second order kinetic model (R2 = 0.9934) are suitably described the monolayer and chemisorption of CTX adsorption. The maximum adsorption capacity of Fe@ACP is 651.6 mg g- 1. Consequently, the developed treatment process revealed successful performance for quick and efficient removal of CTX by Fe@ACP. The developed process introduced an economic and green approach for the comprehensive utilization of agricultural waste resources used for environmental pollution control.

Nano La(OH)3 modified lotus seedpod biochar: A novel solution for effective phosphorus removal from wastewater

Effective removal of phosphorus from water is crucial for controlling eutrophication. Meanwhile, the post-disposal of wetland plants is also an urgent problem that needs to be solved. In this study, seedpods of the common wetland plant lotus were used as a new raw material to prepare biochar, which were further modified by loading nano La(OH)3 particles (LBC-La). The adsorption performance of the modified biochar for phosphate was evaluated through batch adsorption and column adsorption experiments. Adsorption performance of lotus seedpod biochar was significantly improved by La(OH)3 modification, with adsorption equilibrium time shortened from 24 to 4 h and a theoretical maximum adsorption capacity increased from 19.43 to 52.23 mg/g. Moreover, LBC-La maintained a removal rate above 99% for phosphate solutions with concentrations below 20 mg/L. The LBC-La exhibited strong anti-interference ability in pH (3-9) and coexisting ion experiments, with the removal ratio remaining above 99%. The characterization analysis indicated that the main mechanism is the formation of monodentate or bidentate lanthanum phosphate complexes through inner sphere complexation. Electrostatic adsorption and ligand exchange are also the mechanisms of LBC-La adsorption of phosphate. In the dynamic adsorption experiment of simulated wastewater treatment plant effluent, the breakthrough point of the adsorption column was 1620 min, reaching exhaustion point at 6480 min, with a theoretical phosphorus saturation adsorption capacity of 6050 mg/kg. The process was well described by the Thomas and Yoon-Nelson models, which indicated that this is a surface adsorption process, without the internal participation of the adsorbent.