Academic Publications
My Publications
2022
Perera, PLRA; Perera, WPRT; Liyanage, JA; Premaratne, WAPJ
A comparison of food contamination by heavy metals/metalloids in CKDu prevalent areas and a reference area; A study in Sri Lanka Proceedings Article
In: International Postgraduate Research Conference, pp. 99, Faculty of Graduate Studies, University of Kelaniya Sri Lanka, 2022.
Abstract | Links | BibTeX | Tags: Arsenic, Cadmium, chronic kidney disease, CKDu, Food Safety, Heavy metals, Lead, Nephropathy
@inproceedings{perera2022comparison,
title = {A comparison of food contamination by heavy metals/metalloids in CKDu prevalent areas and a reference area; A study in Sri Lanka},
author = {PLRA Perera and WPRT Perera and JA Liyanage and WAPJ Premaratne},
url = {https://www.researchgate.net/publication/367091378_A_comparison_of_food_contamination_by_heavy_metalsmetalloids_in_CKDu_prevalent_areas_and_a_reference_area_A_study_in_Sri_Lanka},
year = {2022},
date = {2022-12-01},
urldate = {2022-12-01},
booktitle = {International Postgraduate Research Conference},
volume = {2022},
pages = {99},
publisher = {Faculty of Graduate Studies, University of Kelaniya Sri Lanka},
abstract = {During the past two decades, so many studies have been involved in exploring the relationship between the prevalence of chronic kidney disease of unknown etiology (CKDu) and exposure to toxic metals. These studies revealed signs of chronic low levels of toxic metal exposure in Sri Lanka. To assess the risk of negative health effects and propose appropriate public health interventions, novel research studies will be very beneficial. This assessment was performed to study the toxic metal contamination status in domestic rice, leafy vegetables, legumes, and citrus fruits in the CKDu prevalence area in north central province in Sri Lanka and to compare those levels with a reference area in the Eastern province in Sri Lanka where CKDu is not prevalent. CKDu hot spots areas Maradankulama-Mahakanadarawa in the Anuradhapura district, Sri Lanka was selected for sampling and Buddhangala Grama Niladhari area in Ampara district was selected as a reference site. Food samples, including (Oryza sativa; n=25, Centella asiatica; n=25, Citrus crenatiflora; n=18, Vigna radiata; n=10) were collected from the stratified sampling method in both areas and the collected food samples were digested by microwave digestion according to the standard procedures and the concentrations of metal ions in food samples, including Cadmium, Nickel, Chromium, Copper, Iron, Manganese, Lead, Zinc, Arsenic, and Calcium, were measured using Inductive Coupled Plasma technique (ICP). As a results of the study, mean As and Pb concentrations of Oryza sativa (As-0.15 mg/kg, Pb-3.10 mg/kg) and Citrus crenatiflora (As-0.15 mg/kg, Pb-0.47 mg/kg), Pb (0.65 mg/kg) and Cd (0.05 mg/kg) content in Centella asiatica, and mean concentrations of As (0.14 mg/kg), Pb (9.25 mg/kg) and Cu (57.8 mg/kg) in Vigna radiata have exceeded the permissible limits given by the FAO and WHO, 2011: As-0.1 mg/kg, Pb-0.1 mg/kg, Cd-0.05 mg/kg, Cr-2.3 mg/kg, Cu-40 mg/kg. However, none of the food samples collected from the reference areas has exceeded the permissible limits of analyzed heavy metals/metalloids. THQ (Target Hazard Quotient) values of Cr have exceeded the threshold values for all food species. Furthermore, Pb is also regarded as a toxic element and THQ values of Pb in Oryza sativa and Vigna radiate are noticeably high. Meanwhile, THQ values of the food samples in the reference areas have not exceeded the threshold values. According to the outcome of the study, there is a noticeable difference reported in toxic metals contamination status between the CKDu-prone areas and the reference area. Therefore, the consumption of analyzed rice, leafy vegetables, and legumes was estimated to be risky, and their regular consumption may boost the likelihood of CKDu prevalence in those areas. Further studies are required to monitor and assess heavy metals and metalloids in soil, and fertilizers to find the pathways of contamination of food by toxic metals.},
keywords = {Arsenic, Cadmium, chronic kidney disease, CKDu, Food Safety, Heavy metals, Lead, Nephropathy},
pubstate = {published},
tppubtype = {inproceedings}
}
Perera, WPRT; Perera, PLRA; Kumarasingha, AR; Liyanage, JA
Adsorptive removal of Cd (II) from aqueous solutions by sand/graphite oxide nano-composites: characterization, isotherm, and kinetic studies Proceedings Article
In: International Postgraduate Research Conference (IPRC) , pp. 93, Faculty of Graduate Studies, University of Kelaniya Sri Lanka, 2022.
Abstract | Links | BibTeX | Tags: Adsorption, Cadmium, Graphene oxide, Isotherm, Kinetic, Sand
@inproceedings{perera2022adsorptive,
title = {Adsorptive removal of Cd (II) from aqueous solutions by sand/graphite oxide nano-composites: characterization, isotherm, and kinetic studies},
author = {WPRT Perera and PLRA Perera and AR Kumarasingha and JA Liyanage},
url = {https://www.researchgate.net/publication/367161154_Adsorptive_removal_of_Cd_II_from_aqueous_solutions_by_sandgraphite_oxide_nano-composites_characterization_isotherm_and_kinetic_studies},
year = {2022},
date = {2022-12-01},
urldate = {2022-12-01},
booktitle = {International Postgraduate Research Conference (IPRC) },
volume = {2022},
pages = {93},
publisher = {Faculty of Graduate Studies, University of Kelaniya Sri Lanka},
abstract = {Core-shell absorbent granules were developed by coating commercial sand gravels with graphite oxide (few-layer oxidized graphene sheets). Graphite oxide (GO) is synthesized chemically from vein graphite, a rare form of high-purity natural graphite (NVG). Modified Hammer's method was followed in order to synthesize graphene oxide from the NVG. Repeated coatings of graphite oxide on the sand followed by low temperature (120 0 C) thermal pyrolysis resulted in core-shell granules with a hierarchical structure in which sand gravels are covered by graphite oxide layers. Five times GO coated water stable sand/graphite oxide nano-composites (M-S/GO) were developed for further adsorption studies. The adsorption performance and mechanism of Cd (II) removal were investigated and FT-IR, SEM, EDX, and XPS were used to characterize the (M-S/GO) as spectroscopic and microscopic characterization methods. Optimization studies were carried out to find the effective pH of the media, dosage, initial concentration of Cd (II), and contact time that reached the equilibrium. Apart from that, the models of kinetics (pseudo-first order and pseudo-second order), and isotherms (Langmuir and Freundlich) were introduced. Characterization findings indicated that un-uniform graphene oxide coatings had been constructed on the sand surface and the surface of the nano-composite comprised of oxygen-based functional groups. Under optimum conditions (0.08 g/L of dosage, 65 mg/L initial Cd concentration, 120 min of contact time), the M-S/GO removed 93.8% of Cd (II) from simulated water at pH 8.0 (30 ± 2 ℃) and the process reached equilibrium after 120 minutes. The adsorption capacity of Cd (II) was augmented when increasing the pH of the medium up to pH=8, and then it tended to reduce. Further, the experimental data have been fitted with the Langmuir isotherm model indicating that monolayer adsorption of Cd (II) occurs on the surface of M-S/GO. Apart from that, M-S/GO had a maximum adsorption capacity (mg/g) (Qmax) value for Cd (II) adsorption (16.12 mg/g) than sand and GO, the equilibrium parameter (RL) value in this study was 0.071, which indicates that Cd (II) adsorption onto the surface of the M-S/GO is favorable. The experiment kinetic data were best fitted to a pseudo-second-order kinetic model indicating that Cd (II) has adsorbed onto the surface of the M-S/GO by a chemical sorption mechanism. These findings imply that M-S/GO could be used as an effective adsorbent for removing Cd (II) from contaminated water sources. More research is required to determine the reusability of M-S/GO in the adsorptive removal process.},
keywords = {Adsorption, Cadmium, Graphene oxide, Isotherm, Kinetic, Sand},
pubstate = {published},
tppubtype = {inproceedings}
}