Biosorption of Cu(II) ions as a method for the effective use of activated carbon from grape stalk waste: RMS optimization and kinetic studies

ABSTRACT

This study was undertaken to examine the effect of such biosorption factors as initial Cu(II) concentration, biosorbent dosage, reaction temperature, contact time and mixing speed on the efficiency of removal Cu(II) ions from wastewater using activated carbon from grape stalk waste. In this case, Response Surface Methodology (RSM) was used in conjunction with a Box–Behnken design of experiments to predict the final Cu(II) concentration (C_Fin), while considering the previously mentioned biosorption factors. In an attempt to obtain the maximum removal of final Cu(II) concentration, while minimizing energy consumption, the Multi-Response Surface Methodology (MRS) was used. Three possible optimizations were proposed for the maximum elimination of final Cu(II) in this case. The maximum (100 mg/L), minimum (2 mg/L) and intermediate (51 mg/L) values of the study were used for the initial Cu(II) concentration. The optimal values that were reached were 92.21% when the initial copper concentration was 51 mg/L and the activated carbon dose, temperature, mixing speed and reaction time, were, respectively, 0.895 g/L, 20.036°C, 105.313 rpm and 30.181 s. Also, in regard to thermodynamic studies, the experimental equilibrium data provided a good fit using the Freundlich model, whereas the kinetic data were efficiently by the pseudo-second order. These results support the use of grape stalk waste in the production of activated carbon for the removal of Cu(II) ions from water. This could help to improve the economics of treating wastewater.

KEYWORDS:

• Heavy metals
• cu(II) ions
• grape stalk waste
• bio-waste
• biosorption
• optimization

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors wish to express their appreciation for the financial support of La Rioja Government through ADER 2019-IIDD-00047 project.

Notes on contributors

Marina Corral-Bobadilla

Marina Corral-Bobadilla B.S (2000), M.S (2002), and Ph.D (2011) in industrial engineering from the University of La Rioja, Spain. She is a lecturer in the Mechanical Engineering Department at the University of La Rioja, Spain. Since 2007, She has investigated various approaches to Environmental Engineering. Her fields of study include wastewater treatment technologies and environmental modeling.

Rubén Lostado-Lorza

Rubén Lostado-Lorza is a full professor and researcher who currently works in the Department of Mechanical Engineering of the University of La Rioja in Spain. Prior to his academic career, Rubén was employed as a simulation engineer in the research and development (R&D) departments of several Spanish companies where he used FEM. His areas of research include modeling and optimization of mechanical elements using both FEM and biomechanics.

Fátima Somovilla-Gómez

Fátima Somovilla-Gómez received her degree in mechanical engineering from the University of La Rioja, Spain, in 2000 and her Ph.D. in engineering at University of La Rioja, in 2020. Since 2020, she has served as an Associate Professor in the Mechanical Engineering Department. Her research interests includes computational biomechanics, biomedical modeling using the Finite Element Method (FEM) and environmental modeling in wastewater treatment technologies.

Rubén Escribano-García

Rubén Escribano-García is Senior Researcher at LORTEK Technological Centre. He has worked at different companies in different sectors, such as manufacturing, construction and transport. Ruben has wide experience in finite element method, CAD/CAE, machine learning, optimization techniques, programming, Design of Experiments and project management. Currently, he is focus on simulation and optimization of welding processes and products for additive manufacturing.