A novel green approach for Cr(VI) removal: application of tomato stem-based hydrochar assisted Fenton-like process

ABSTRACT

Environmentally friendly catalysts have come to the forefront due to the cost of chemically produced catalysts and the formation of by-products harmful to the environment. Millions of tons of plant waste are produced every year, some of which is disposed directly. In this study, tomato stem hydrochar (TSCH) was produced from waste tomato stems by the hydrothermal carbonisation (HTC) method, and its use as a catalyst was investigated. The optimisation of Cr(VI) removal from water was carried out using a Fenton-like process with a TSCH catalyst and resulted in 100% of Cr(VI) removal efficiency at 10 mg/L of Cr(VI) concentration, pH 2.00, 0.2 g/L of TSCH catalyst, 10 µL/L of H₂O₂ and 60 minutes of reaction time. Fenton-like thermodynamic and kinetic data were analyzed, and the results were found to comply with the second-order in Cr(VI) removal. The reusability of the TSCH catalyst in Cr(VI) removal was investigated and it was emphasized that it was reusable for more than 5 uses. In conclusion, TSCH, which is an environmentally friendly, inexpensive and effective catalyst for Cr(VI) treatment in a Fenton-like process, can be used as an alternative catalyst for wastewater treatment in terms of both waste management and economic and environmentally friendly.

GRAPHICAL ABSTRACT

KEYWORDS:

• Fenton-like
• Cr(VI) removal
• hydrochar
• heterogeneous catalyst
• tomato stem

Disclosure statement

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

Declarations

Ethical Approval: Ethics approval was not required for this study.

Authors’ contributions: AA, PB, MG: Methodology, Data Curation.

ZI, OE: Conceptualization, Investigation, Writing- Original Draft, Review & Editing.

EY, ND: Conceptualization, Writing- Original Draft, Formal Analysis, Review & Editing, Supervision.

Availability of data and materials

The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.

Additional information

Notes on contributors

Aya Alterkaoui

Aya Alterkaoui is an MSc student at Mersin University. Her research interests are in wastewater treatment technologies.

Pınar Belibağlı

Pınar Belibağlı is a PhD student at Tarsus University. Her research interests are in wastewater treatment technologies and renewable energy.

Melis Gun

Melis Gun is a PhD student at Mersin University. Her research interests are in wastewater treatment technologies.

Zelal Isik

Zelal Isik is a PhD student at Mersin University. Her research interests are in wastewater treatment and membrane filtration technologies.

Ozan Eskikaya

Ozan Eskikaya is a PhD student at Tarsus University. His research interests are in wastewater treatment technologies and renewable energy.

Erdal Yabalak

Erdal Yabalak has been Assoc. Prof. of Chemistry since 2019 and currently works in the Department of Chemistry and Chemical Processing Technology, at Mersin University. He received his BSc (Chemistry) from Mersin University, Faculty of Arts and Sciences, Department of Chemistry in 2008, and his MSc and PhD degrees from Mersin University, Institute of Science and Technology, Department of Chemistry, in 2011 and 2015, respectively. He was a research assistant between 2008 and 2015 and a Dr. research assistant between 2015 and 2019. His research areas include extraction, solubility and degradation, and sub/supercritical fluids synthesis. Additionally, his research interests include chromatography, water purification, environmental and analytical chemistry, hydrochar production and utilisation, and nanotechnology, as well as analysis of the chemical contents of endemic plants and determination of antioxidants and other bioactive compounds.

Nadir Dizge

Nadir Dizge is a Professor at Mersin University. His research interests are in wastewater treatment and membrane filtration technologies.