Academic Publications
My Publications
2025
Perera, WPRT; Perera, PLRA; Ruwanthi, NMN; Vitharama, AVAP; Kannangara, Amila; Liyanage, JA; Kumarasinghe, AR
Enhanced adsorption of MCPA pesticide using a novel sand/graphene oxide composite Journal Article
In: Journal of Multidisciplinary & Translational Research, vol. 10, iss. 1, pp. 10-24, 2025.
Abstract | Links | BibTeX | Tags: Adsorption, Adsorptive removal, Graphene oxide, MCPA, Pesticide, Sand
@article{Perera2025c,
title = {Enhanced adsorption of MCPA pesticide using a novel sand/graphene oxide composite},
author = {WPRT Perera and PLRA Perera and NMN Ruwanthi and AVAP Vitharama and Amila Kannangara and JA Liyanage and AR Kumarasinghe},
url = {https://rajithperera.com/wp-content/uploads/2025/11/68b52d739c34a.pdf},
doi = {10.4038/jmtr.v10i1.77},
year = {2025},
date = {2025-09-01},
journal = {Journal of Multidisciplinary & Translational Research},
volume = {10},
issue = {1},
pages = {10-24},
abstract = {Developing graphene-based composites for mitigating water pollutants is crucial, as current composites often have limitations, including their specific adsorption behavior towards only one type of contaminant. Additionally, these existing composites are associated with high costs, challenging recovery processes, and potential toxicity to both the environment and human health. Multiple coated sand/graphene oxide composites (M-GO/S) present a promising solution to these challenges. In this study, we focused on investigating the adsorptive removal of the pesticide 2-methyl-4-chlorophenoxyacetic acid (MCPA) using M-GO/S composites. Additionally, we aimed to elucidate the underlying adsorption mechanism and develop an HPLC method for analyzing MCPA. The retention time for MCPA was determined to be 1.538 minutes. The optimal parameters for MCPA adsorption onto M-GO/S were established as a 75 mg/L MCPA concentration, a dosage of 0.05 g, and a contact period of 105 minutes at neutral pH. The isotherm studies indicate that it is challenging to distinctly classify the adsorption process using the Langmuir and Freundlich models, as they show similar R2 values. This may be attributed to the likely occurrence of multilayered attachment of MCPA following an initial monolayer adsorption. The adsorption intensity (n) value of 0.625 further suggests that complex interactions are involved in MCPA adsorption, likely due to the surface complexity of the M-GO/S composite. Apart from that, the kinetics studies revealed that the rate-controlling step involves chemical adsorption between the surface of M-GO/S and MCPA. Chemical interactions arise through hydrogen bonding and critical interactions between the hydroxyl groups on M-GO/S and the aromatic rings of MCPA. M-GO/S is a promising candidate for the adsorptive removal of negatively charged pesticide molecules like MCPA. It outperforms activated carbon and sand in effectiveness, and it is more advantageous than graphene oxide due to its simple recovery process},
keywords = {Adsorption, Adsorptive removal, Graphene oxide, MCPA, Pesticide, Sand},
pubstate = {published},
tppubtype = {article}
}
Developing graphene-based composites for mitigating water pollutants is crucial, as current composites often have limitations, including their specific adsorption behavior towards only one type of contaminant. Additionally, these existing composites are associated with high costs, challenging recovery processes, and potential toxicity to both the environment and human health. Multiple coated sand/graphene oxide composites (M-GO/S) present a promising solution to these challenges. In this study, we focused on investigating the adsorptive removal of the pesticide 2-methyl-4-chlorophenoxyacetic acid (MCPA) using M-GO/S composites. Additionally, we aimed to elucidate the underlying adsorption mechanism and develop an HPLC method for analyzing MCPA. The retention time for MCPA was determined to be 1.538 minutes. The optimal parameters for MCPA adsorption onto M-GO/S were established as a 75 mg/L MCPA concentration, a dosage of 0.05 g, and a contact period of 105 minutes at neutral pH. The isotherm studies indicate that it is challenging to distinctly classify the adsorption process using the Langmuir and Freundlich models, as they show similar R2 values. This may be attributed to the likely occurrence of multilayered attachment of MCPA following an initial monolayer adsorption. The adsorption intensity (n) value of 0.625 further suggests that complex interactions are involved in MCPA adsorption, likely due to the surface complexity of the M-GO/S composite. Apart from that, the kinetics studies revealed that the rate-controlling step involves chemical adsorption between the surface of M-GO/S and MCPA. Chemical interactions arise through hydrogen bonding and critical interactions between the hydroxyl groups on M-GO/S and the aromatic rings of MCPA. M-GO/S is a promising candidate for the adsorptive removal of negatively charged pesticide molecules like MCPA. It outperforms activated carbon and sand in effectiveness, and it is more advantageous than graphene oxide due to its simple recovery process
2023
Perera, WPRT; Ruwanthi, NMN; Perera, PLRA; Kannangara, Amila; Premaratne, WAPJ; Liyanage, JA; Kumarasinghe, AR
Development of sand/graphene composite and its application for MCPA pesticide adsorption from water Proceedings Article
In: International Conference on Applied and Pure Sciences (ICAPS), pp. 113, University of Kelaniya, Sri Lanka, 2023.
Abstract | Links | BibTeX | Tags: Adsorption, Graphene oxide, Kinetic, Pesticide, Sand
@inproceedings{Perera2023b,
title = {Development of sand/graphene composite and its application for MCPA pesticide adsorption from water},
author = {WPRT Perera and NMN Ruwanthi and PLRA Perera and Amila Kannangara and WAPJ Premaratne and JA Liyanage and AR Kumarasinghe},
url = {https://www.researchgate.net/publication/374847773_Development_of_sandgraphene_composite_and_its_application_for_MCPA_pesticide_adsorption_from_water},
year = {2023},
date = {2023-10-13},
booktitle = {International Conference on Applied and Pure Sciences (ICAPS)},
number = {49},
pages = {113},
publisher = {University of Kelaniya, Sri Lanka},
abstract = {This research endeavours to synthesize a novel adsorbent, sand/graphene oxide composite (M-GO/S), achieved through the iterative deposition of graphene oxide layers on river sand employing a thermal annealing process. Scanning electron microscopic (SEM) and Fourier-transform infrared spectroscopy (FT-IR) characterization studies revealed the presence of a non-uniform graphene oxide coating on the surface of the sand and the incorporation of oxygenated functional moieties within the structure. Comparative evaluations show the heightened adsorption capacity of this new composite entity with alternative sorbent materials, such as activated carbon, graphene oxide, and sand to adsorb neutral 2-methyl-4-chlorophenoxyacetic acid (MCPA) pesticide molecule. To analyse the MCPA adsorption parameters, High-performance liquid chromatography (HPLC)was used (Solvent mixture-Acetonitrile: Distilled water (1:1); Flow rate-1.5µLmin-1; Wave length-275nm). The retention time for the MCPA was reported as 1.538s. The optimization studies and adsorption modelling were carried out, focusing on the adsorption of MCPA onto the M-GO/S. Accordingly, the optimum concentration, dosage, and contact time were 75 mg/L, 0.05 g, and 105 minutes respectively, at neutral pH values. The investigation of adsorption equilibrium isotherms has highlighted the Freundlich model's (multilayer adsorption) superior explanatory capacity in characterizing the adsorption phenomenon. Concurrently, the analysis of adsorption kinetics has demonstrated a favourable fit with the pseudo-second-order model (with a correlation coefficient denoted as 0.9754), implying a prevailing chemical sorption mechanism underlying the adsorption process. Although MCPA possesses either neutral or negatively charged (upon dissolution) surfaces, the M-GO/S composite exhibits significant adsorption capability towards MCPA. Consequently, the synthesized composite emerges as a viable candidate for effectively mitigating MCPA pesticide contamination from water.},
keywords = {Adsorption, Graphene oxide, Kinetic, Pesticide, Sand},
pubstate = {published},
tppubtype = {inproceedings}
}
This research endeavours to synthesize a novel adsorbent, sand/graphene oxide composite (M-GO/S), achieved through the iterative deposition of graphene oxide layers on river sand employing a thermal annealing process. Scanning electron microscopic (SEM) and Fourier-transform infrared spectroscopy (FT-IR) characterization studies revealed the presence of a non-uniform graphene oxide coating on the surface of the sand and the incorporation of oxygenated functional moieties within the structure. Comparative evaluations show the heightened adsorption capacity of this new composite entity with alternative sorbent materials, such as activated carbon, graphene oxide, and sand to adsorb neutral 2-methyl-4-chlorophenoxyacetic acid (MCPA) pesticide molecule. To analyse the MCPA adsorption parameters, High-performance liquid chromatography (HPLC)was used (Solvent mixture-Acetonitrile: Distilled water (1:1); Flow rate-1.5µLmin-1; Wave length-275nm). The retention time for the MCPA was reported as 1.538s. The optimization studies and adsorption modelling were carried out, focusing on the adsorption of MCPA onto the M-GO/S. Accordingly, the optimum concentration, dosage, and contact time were 75 mg/L, 0.05 g, and 105 minutes respectively, at neutral pH values. The investigation of adsorption equilibrium isotherms has highlighted the Freundlich model's (multilayer adsorption) superior explanatory capacity in characterizing the adsorption phenomenon. Concurrently, the analysis of adsorption kinetics has demonstrated a favourable fit with the pseudo-second-order model (with a correlation coefficient denoted as 0.9754), implying a prevailing chemical sorption mechanism underlying the adsorption process. Although MCPA possesses either neutral or negatively charged (upon dissolution) surfaces, the M-GO/S composite exhibits significant adsorption capability towards MCPA. Consequently, the synthesized composite emerges as a viable candidate for effectively mitigating MCPA pesticide contamination from water.