The adsorption of methylene blue dye (MBD) from aqueous solutions was investigated using a new composite made up of shrimp waste chitosan and zeolite as adsorbent. Response surface methodology (RSM) was used to optimize the effects of process variables, such as contact time, pH, adsorbent dose and initial MBD concentration on dye removal. The results showed that optimum conditions for removal of MBD were adsorbent dose of 2.5 g/L and pH of 9.0, and initial MBD concentration of 43.75mg/L and contact time of 138.65 min. The initial concentration of dye had the greatest influence on MBD adsorption among other variables. The experimental data were well fitted by the pseudo-second order kinetic model, while the Freundlich isotherm model indicated a good ability for describing equilibrium data. According to this isotherm model, maximum adsorption capacity of the composite was 24.5mg/g. Desorption studies showed that the desorption process is favored at low pH under acidic conditions
a b s t r a c tIn this research, electrocoagulation (EC) was studied to investigate the efficiency of amoxicillin (AMX) antibiotic removal using iron electrodes from aqueous solution. For this purpose, a central composite design (CCD) was employed to optimize the operating parameters including pH (2-12), current density (5-15 mA·cm -2 ), AMX concentration (10-100 mg·L -1 ), and electrode spacing (1-3 cm). Experiments were performed in batch mode at the constant time of 35 min. The residual concentration of AMX in samples was analyzed by measuring the AMX concentration through high-performance liquid chromatography (HPLC). Further, pollutant removal, sludge generation, and energy consumption were measured and discussed through response surface methodology (RSM). The results showed that the removal efficiency was achieved as 80.9% under optimized levels of parameters (pH: 7.87, current density: 10.17 mA·cm -2 , AMX concentration: 50 mg·L -1 , and electrode spacing: 1.5 cm), while sludge generation and energy consumption was 70.3 ml and 7.109 kWh·m -3 , respectively. The results revealed that at same conditions of all variables just one level reduction in current density has lead to the reduction to less than half of the energy consumption.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.