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The adsorption-desorption behaviour of heavy metals in aquatic environments is complex and the processes are regulated by the continuous interactions between water and sediments. This study provides a quantitative understanding of the effects of nutrients and key water and sediment properties on the adsorption-desorption behaviour of heavy metals in riverine and estuarine environments. The influence levels of the environmental factors were determined as conditional regression coefficients. The research outcomes indicate that the mineralogical composition of sediments, which influence other sediment properties, such as specific surface area and cation exchange capacity, play the most important role in the adsorption and desorption of heavy metals. It was found that particulate organic matter is the most influential nutrient in heavy metals adsorption in the riverine environment, while particulate phosphorus is more important under estuarine conditions. Dissolved nutrients do not exert a significant positive effect on the release of heavy metals in the riverine area, whilst dissolved phosphorus increases the transfer of specific metals from sediments to the overlying water under estuarine conditions. Furthermore, the positive interdependencies between marine-related ions and the release of most heavy metals in the riverine and estuarine environments indicate an increase in the mobility of heavy metals as a result of cation exchange reactions.
Lorena S. Miranda; Buddhi Wijesiri; Godwin A. Ayoko; Prasanna Egodawatta; Ashantha Goonetilleke. WATER-SEDIMENT INTERACTIONS AND MOBILITY OF HEAVY METALS IN AQUATIC ENVIRONMENTS. Water Research 2021, 202, 117386 .
AMA StyleLorena S. Miranda, Buddhi Wijesiri, Godwin A. Ayoko, Prasanna Egodawatta, Ashantha Goonetilleke. WATER-SEDIMENT INTERACTIONS AND MOBILITY OF HEAVY METALS IN AQUATIC ENVIRONMENTS. Water Research. 2021; 202 ():117386.
Chicago/Turabian StyleLorena S. Miranda; Buddhi Wijesiri; Godwin A. Ayoko; Prasanna Egodawatta; Ashantha Goonetilleke. 2021. "WATER-SEDIMENT INTERACTIONS AND MOBILITY OF HEAVY METALS IN AQUATIC ENVIRONMENTS." Water Research 202, no. : 117386.
Bioavailability is a critical facet of metal toxicity. Although past studies have investigated the individual role of sediment physico-chemical properties in relation to the bioavailability of heavy metals, their collective effects are little-known. Further, limited knowledge exists on the contribution of nutrients to metal bioavailability. In this study, the influence of physico-chemical properties of sediments, including total organic carbon (TOC), total phosphorus (TP), total nitrogen (TN), cation exchange capacity (CEC), specific surface area (SSA), and mineralogical composition to metal bioavailability is reported. The weak-acid extraction method was used to measure Cd, Cr, Cu, Ni, Pb and Zn as the potentially bioavailable fraction in sediments in an urban creek. The results confirmed that Cu has strong selectivity for organic matter (r = 0.814, p < 0.01). Cr bioavailability was influenced by either sediment mineralogy, nutrients, CEC or SSA. Zn, Ni and Pb showed strong affinity to mineral oxides, though their preferred binding positions were with nutrients, particularly organic matter (r = 0.794, 0.809, and 0.753, p < 0.01, respectively). The adsorption of Cd was strongly influenced by the competition with other metals and its bioavailability was weakly influenced by ion exchange (CEC: r = 0.424, p < 0.01). The study results indicate that nitrogen and phosphorus compounds can elevate metal bioavailability due to complexation reactions. Generally, the estuarine area was more favourable for the adsorption of weakly-bound metals. This is concerning as estuaries generate high biogeochemical activity and are economically important.
Lorena S. Miranda; Godwin A. Ayoko; Prasanna Egodawatta; Wan-Ping Hu; Osama Ghidan; Ashantha Goonetilleke. Physico-chemical properties of sediments governing the bioavailability of heavy metals in urban waterways. Science of The Total Environment 2021, 763, 142984 .
AMA StyleLorena S. Miranda, Godwin A. Ayoko, Prasanna Egodawatta, Wan-Ping Hu, Osama Ghidan, Ashantha Goonetilleke. Physico-chemical properties of sediments governing the bioavailability of heavy metals in urban waterways. Science of The Total Environment. 2021; 763 ():142984.
Chicago/Turabian StyleLorena S. Miranda; Godwin A. Ayoko; Prasanna Egodawatta; Wan-Ping Hu; Osama Ghidan; Ashantha Goonetilleke. 2021. "Physico-chemical properties of sediments governing the bioavailability of heavy metals in urban waterways." Science of The Total Environment 763, no. : 142984.
Stormwater runoff pollution has become a key environmental issue in urban areas. Reliable estimation of stormwater pollutant discharge is important for implementing robust water quality management strategies. Even though significant attempts have been undertaken to develop water quality models, deterministic approaches have proven inappropriate as they do not address the variability in stormwater quality. Due to the random nature of rainfall characteristics and the differences in catchment characteristics, it is difficult to generate the runoff pollutographs to a desired level of certainty. Bayesian hierarchical modelling is an effective tool for developing complex models with a large number of sources of variability. A Bayesian model does not look for a single value of the model parameters, but rather determines a distribution of the model parameters from which all inference is drawn. This study introduces a Bayesian hierarchical linear regression model to describe a catchment specific runoff pollutograph incorporating the associated uncertainties in the model parameters. The model incorporates catchment and rainfall characteristics including the effective impervious area, time of concentration, rain duration, average rainfall intensity and the antecedent dry period as the contributors to random effects.
Thamali Perera; James McGree; Prasanna Egodawatta; K.B.S.N. Jinadasa; Ashantha Goonetilleke. A Bayesian approach to model the trends and variability in urban stormwater quality associated with catchment and hydrologic parameters. Water Research 2021, 197, 117076 .
AMA StyleThamali Perera, James McGree, Prasanna Egodawatta, K.B.S.N. Jinadasa, Ashantha Goonetilleke. A Bayesian approach to model the trends and variability in urban stormwater quality associated with catchment and hydrologic parameters. Water Research. 2021; 197 ():117076.
Chicago/Turabian StyleThamali Perera; James McGree; Prasanna Egodawatta; K.B.S.N. Jinadasa; Ashantha Goonetilleke. 2021. "A Bayesian approach to model the trends and variability in urban stormwater quality associated with catchment and hydrologic parameters." Water Research 197, no. : 117076.
Rivers are viewed as major pathways of microplastic transport from terrestrial areas to marine ecosystems. However, there is paucity of knowledge on the dispersal pattern and transport of microplastics in river sediments. In this study, a three dimensional hydrodynamic and particle transport modelling framework was created to investigate the dispersal and transport processes of microplastic particles commonly present in the environment, namely, polyethylene (PE), polypropylene (PP), polyamide (PA), and polyethylene terephthalate (PET) in river sediments. The study outcomes confirmed that sedimental microplastics with lower density would have higher mobility. PE and PP are likely to be transported for a relatively longer distance, while PA and PET would likely accumulate close to source points. High water flow would transport more microplastics from source points, and high flow velocity in bottom water layer are suggested to facilitate the transport of sedimental microplastics. Considering the limited dispersal and transport, the study outcomes indicated that river sediments would act as a sink for microplastic pollutants instead of being a transport pathway. The patchiness associated with the hotspots of different plastic types is expected to provide valuable information for microplastic source tracking.
Beibei He; Mitchell Smith; Prasanna Egodawatta; Godwin A. Ayoko; Llew Rintoul; Ashantha Goonetilleke. Dispersal and transport of microplastics in river sediments. Environmental Pollution 2021, 279, 116884 .
AMA StyleBeibei He, Mitchell Smith, Prasanna Egodawatta, Godwin A. Ayoko, Llew Rintoul, Ashantha Goonetilleke. Dispersal and transport of microplastics in river sediments. Environmental Pollution. 2021; 279 ():116884.
Chicago/Turabian StyleBeibei He; Mitchell Smith; Prasanna Egodawatta; Godwin A. Ayoko; Llew Rintoul; Ashantha Goonetilleke. 2021. "Dispersal and transport of microplastics in river sediments." Environmental Pollution 279, no. : 116884.
In this study, the ability of the aerobic biogranulation process to remove organic matter, total nitrogen, and total phosphorous from wastewater was investigated. The effect of organic matter load on the quality of the produced biogranules and settling velocity of the generated biomass was also investigated. Four different aerobic scenarios were studied in sequential batch bioreactors (SBR) to identify the best operating conditions. The experimental setup consisted of four bioreactors containing 300 mL samples (100 mL of sludge and 200 mL of sweet whey at four different concentrations) under constant stirring (150 rpm), room temperature, and controlled pH (e.g., 7.98 ± 0.25). The different organic matter loads were calculated as the chemical oxygen demand (COD) concentration at 1157 (A), 719 (B), 357 (C), and 202 mg/L (D), respectively. The process consisted of cycles of initial feast followed by 72 h of famine. During the experiments, COD, total nitrogen (TN), and total phosphorus (TP) were measured at the beginning (t0) and the end of the process. The results confirmed that the best conditions were found in the bioreactor with the highest COD load (1157 mg/L), which achieved 98.7 % reduction in organic matter, 45.6 % reduction in TP, and 99.4 % reduction in TN after 9 days with final average sludge settling velocity of 0.7 m/h. The biogranulation process achieved improved clarification of the supernatant, showing increased settling velocity in all of the bioreactors. Microscopic observation confirmed uniform morphology (e.g., spherical or cylindrical) with the biggest biogranules being observed in bioreactors A and B. Organic load was found to play a significant role in biogranules formation and the achievement of the highest organic matter removal, sludge volume reduction, and water clarification. The overall trend in final sludge settling velocity measured in the different bioreactors was C > B > D > A, and in all of them settling was faster than the untreated sample. The results of this study confirm the high potential of biogranulation process for the treatment of wastewater with high organic matter content.
M.A. Gomez-Gallegos; R. Reyes-Mazzoco; D.X. Flores-Cervantes; Ayomi Jarayathne; Ashantha Goonetilleke; Erick R. Bandala; J.L. Sanchez-Salas. Role of organic matter, nitrogen and phosphorous on granulation and settling velocity in wastewater treatment. Journal of Water Process Engineering 2021, 40, 101967 .
AMA StyleM.A. Gomez-Gallegos, R. Reyes-Mazzoco, D.X. Flores-Cervantes, Ayomi Jarayathne, Ashantha Goonetilleke, Erick R. Bandala, J.L. Sanchez-Salas. Role of organic matter, nitrogen and phosphorous on granulation and settling velocity in wastewater treatment. Journal of Water Process Engineering. 2021; 40 ():101967.
Chicago/Turabian StyleM.A. Gomez-Gallegos; R. Reyes-Mazzoco; D.X. Flores-Cervantes; Ayomi Jarayathne; Ashantha Goonetilleke; Erick R. Bandala; J.L. Sanchez-Salas. 2021. "Role of organic matter, nitrogen and phosphorous on granulation and settling velocity in wastewater treatment." Journal of Water Process Engineering 40, no. : 101967.
In recent years, the presence of the group of contaminants, termed as microplastics (MPs) has been recognized as significant water pollutants with considerable potential for exerting adverse impacts on human health and wildlife. Natural attenuation has practically no effect while conventional treatment processes are not capable of entirely removing MPs which are reported to accumulate in the environment, in organisms in the aquatic food web and, potentially reaching humans. This in-depth review critically evaluates the state-of-the-art engineered technologies suitable for the separation and degradation of microplastics in water with potential for real-scale application. The outcomes of the review confirmed that very limited number of studies are reported in this field, the majority from recent years and have focused on using phase-changing processes, including coagulation-flocculation, flotation, and membrane processes. A few other studies have reported the use of chemical or biological digestion, and even fewer, engineered removal using biodegradation, wet oxidation, and advanced oxidation processes. This paper focuses on the type of MPs being removed, the process conditions and the outcomes reported in research literature. The emerging trends in the field are also highlighted as well as the identification of current knowledge gaps and future research directions along with perceptive comments and recommendations related to the application of available technologies for water treatment.
Oscar M. Rodríguez-Narvaez; Ashantha Goonetilleke; Leonidas Perez; Erick R. Bandala. Engineered technologies for the separation and degradation of microplastics in water: A review. Chemical Engineering Journal 2021, 414, 128692 .
AMA StyleOscar M. Rodríguez-Narvaez, Ashantha Goonetilleke, Leonidas Perez, Erick R. Bandala. Engineered technologies for the separation and degradation of microplastics in water: A review. Chemical Engineering Journal. 2021; 414 ():128692.
Chicago/Turabian StyleOscar M. Rodríguez-Narvaez; Ashantha Goonetilleke; Leonidas Perez; Erick R. Bandala. 2021. "Engineered technologies for the separation and degradation of microplastics in water: A review." Chemical Engineering Journal 414, no. : 128692.
The isotherm, kinetics, and thermodynamics parameters, and mechanisms involved in the adsorption of Pb2+ and Cu2+ ions from an aqueous solution using engineered hydrochar were investigated. The hydrochar was produced through catalytic hydrothermal carbonization of rice straw at 200 °C with (engineered hydrochar) and without (hydrochar) FeCl3 (1.2 %) as iron catalyst which has been reported to have the ability to enhance surface properties. Batch experiments were conducted to examine the effect of sorbent dosage, pH, and initial metal ion concentration on the adsorptive performance. The results obtained revealed that the addition of iron catalyst increased the surface functional groups, and exhibit better adsorptive performance compared to non-treated hydrochar. The adsorptive performance of engineered hydrochar was higher for Pb2+ compared to Cu2+, which can be explained by surface complexation, cationic- π interaction, and mass diffusion process with the initial removal performance limited by mass transfer process. The Langmuir isotherm model gave the best fit for the adsorption of both metals compared to the other models tested. The adsorption kinetics followed the Lagergren’s pseudo-second order model. Thermodynamic parameters revealed that Pb2+ and Cu2+ adsorption by engineered hydrochar is a spontaneous and endothermic process. Moreover, this study created new knowledge by providing an in-depth understanding of the effect of iron catalyst on the functional properties of engineered hydrochar and its adsorption mechanisms. Research on the use of catalysts in engineered hydrochar for pollutant removal is very limited. In addition, the study outcomes would contribute to the production of highly efficient magnetic hydrochars.
Kannan Nadarajah; Erick R. Bandala; Zhanying Zhang; Sagadevan Mundree; Ashantha Goonetilleke. Removal of heavy metals from water using engineered hydrochar: Kinetics and mechanistic approach. Journal of Water Process Engineering 2021, 40, 101929 .
AMA StyleKannan Nadarajah, Erick R. Bandala, Zhanying Zhang, Sagadevan Mundree, Ashantha Goonetilleke. Removal of heavy metals from water using engineered hydrochar: Kinetics and mechanistic approach. Journal of Water Process Engineering. 2021; 40 ():101929.
Chicago/Turabian StyleKannan Nadarajah; Erick R. Bandala; Zhanying Zhang; Sagadevan Mundree; Ashantha Goonetilleke. 2021. "Removal of heavy metals from water using engineered hydrochar: Kinetics and mechanistic approach." Journal of Water Process Engineering 40, no. : 101929.
The ability of biochar beads embedded with freshwater algae ̶ Chlorella pyrenoidosa (Bc-Cp beads) were investigated for their efficiency in the removal of pollutants. Combining these is an innovative concept which can result in improvements in pollutant removal since both, biochar and algae have the ability for adsorbing/absorbing pollutants. Additionally, only limited work on embedding freshwater algae (common algae existing in surface water and having low ecological risks since they are native species) into biochar for the removal of water pollutants has been undertaken to-date. It was found that Bc-Cp beads prepared using 10 mL of algae (9 × 108 cell/mL), 0.3 g of biochar, 40 g/L of sodium alginate, and 20 g/L of CaCl2 displayed the optimum characteristics including mechanical strength (2.548 N), promotion of algae growth (191.70 % growth rate) and pollutant removal ability with the removal efficiency of ammonia nitrogen, total nitrogen and total phosphorus, total organic carbon, zinc and copper were up to 69.2 %, 43.0 %, 73.8 %, 81.0 %, 74.4 % and 81.0 %, respectively. The algae within the beads were primarily responsible for the removal of nutrients by assimilation, while biochar mainly exerted influence on the removal of organic matter and heavy metals by chemisorption. The study outcomes also confirmed that Bc-Cp beads possess high potential to be used in estuarine environments and saline groundwater.
Qicong Guo; Erick R. Bandala; Ashantha Goonetilleke; Nian Hong; Yuqing Li; An Liu. Application of Chlorella pyrenoidosa embedded biochar beads for water treatment. Journal of Water Process Engineering 2021, 40, 101892 .
AMA StyleQicong Guo, Erick R. Bandala, Ashantha Goonetilleke, Nian Hong, Yuqing Li, An Liu. Application of Chlorella pyrenoidosa embedded biochar beads for water treatment. Journal of Water Process Engineering. 2021; 40 ():101892.
Chicago/Turabian StyleQicong Guo; Erick R. Bandala; Ashantha Goonetilleke; Nian Hong; Yuqing Li; An Liu. 2021. "Application of Chlorella pyrenoidosa embedded biochar beads for water treatment." Journal of Water Process Engineering 40, no. : 101892.
First flush is an important phenomenon commonlyused in stormwater treatment system design where only the highly concentrated initial part of the runoff hydrograph is subject to treatment. Despite the existing methods for estimating the first flush, a robust quantitative definition is difficult to find. This paper discusses a novel approach, where a new parameter is introduced to analyse the variability in the discharge of pollutants at different times throughout a runoff event and thereby enable the identification of first flush. It was found that due to variability in rainfall, the first flush runoff volume varies from event to event. Therefore, a static estimate of the first flush is not applicable for a runoff event. The Monte Carlo simulation undertaken strengthened the analysis by providing credible limits to the outcomes. Accordingly, an interval estimation was obtained in which the first flush runoff can vary, and it was found that most commonly, the first flush can exist through the initial 30%–50% of the runoff. Therefore, in order to treat the stormwater runoff with minimum risk of discharging high loads of pollutants to the receiving water environment, at least the initial 30% of the runoff should be subject to treatment. This understanding provides a fundamental basis for the design of robust stormwater treatment systems.
Thamali Perera; James McGree; Prasanna Egodawatta; K.B.S.N. Jinadasa; Ashantha Goonetilleke. New conceptualisation of first flush phenomena in urban catchments. Journal of Environmental Management 2020, 281, 111820 .
AMA StyleThamali Perera, James McGree, Prasanna Egodawatta, K.B.S.N. Jinadasa, Ashantha Goonetilleke. New conceptualisation of first flush phenomena in urban catchments. Journal of Environmental Management. 2020; 281 ():111820.
Chicago/Turabian StyleThamali Perera; James McGree; Prasanna Egodawatta; K.B.S.N. Jinadasa; Ashantha Goonetilleke. 2020. "New conceptualisation of first flush phenomena in urban catchments." Journal of Environmental Management 281, no. : 111820.
Urban road build-up solids contain toxic metals posing potential risks to human health. Management of human health risks arising from these metals is critical in urban areas. This study collected solids build-up data from 16 study sites with various land use and traffic characteristics. Source quantification was conducted using PCA/APCS receptor model. It was found that soil and asphalt wear are the largest contributors (69.43%) to risk and mainly contribute Al, Cr, Mn, Fe, Ni, Zn and Pb to build-up solids. Brake wear is the second largest contributor accounting for 17.20% and contributes Cd and Cu. Tyre wear is the third major contributor (11.38%) and it primarily contributes Ni, Zn and Cr. Mathematical equations were fitted to estimate the risk against daily traffic volume and land use fractions, and the uncertainty analysis highlighted that risk assessment should account for the variability in metal concentrations rather than a point value of concentrations at a given time and space. Based on source quantification and risk assessment, an integrated risk management model was developed to manage human health risks from toxic metals in build-up solids. This risk model provides guidance for urban planning and land use development to mitigate risk arising from urban road deposited solids.
Yukun Ma; Sandya Mummullage; Buddhi Wijesiri; Prasanna Egodawatta; James McGree; Godwin A. Ayoko; Ashantha Goonetilleke. Source quantification and risk assessment as a foundation for risk management of metals in urban road deposited solids. Journal of Hazardous Materials 2020, 408, 124912 .
AMA StyleYukun Ma, Sandya Mummullage, Buddhi Wijesiri, Prasanna Egodawatta, James McGree, Godwin A. Ayoko, Ashantha Goonetilleke. Source quantification and risk assessment as a foundation for risk management of metals in urban road deposited solids. Journal of Hazardous Materials. 2020; 408 ():124912.
Chicago/Turabian StyleYukun Ma; Sandya Mummullage; Buddhi Wijesiri; Prasanna Egodawatta; James McGree; Godwin A. Ayoko; Ashantha Goonetilleke. 2020. "Source quantification and risk assessment as a foundation for risk management of metals in urban road deposited solids." Journal of Hazardous Materials 408, no. : 124912.
Land use management plays a key role in mitigating urban river pollution. Past research has addressed how primary land uses influence river water and sediment quality, but has given limited attention to the subdivision of primary land uses to a secondary level, limiting the accurate identification of potential sources of pollutants. The current study, using Bayesian Networks, investigated how the hierarchical structure of land use can be employed to accurately characterise the pollution of sediments in two rivers in China and Australia. It was found that the primary land uses are a weak determinant of potential sources of metals, nutrients, and organochlorine pesticides (OCPs). However, secondary land uses provide higher accuracy in determining pollutant sources. The study highlighted that the lack of data to enable the subdivision of land uses can constrain informed decision making for the mitigation of urban water pollution.
Buddhi Wijesiri; An Liu; Ayomi Jayarathne; Godfred Duodu; Godwin A. Ayoko; Lan Chen; Ashantha Goonetilleke. Influence of the hierarchical structure of land use on metals, nutrients and organochlorine pesticides in urban river sediments. Ecological Engineering 2020, 159, 106123 .
AMA StyleBuddhi Wijesiri, An Liu, Ayomi Jayarathne, Godfred Duodu, Godwin A. Ayoko, Lan Chen, Ashantha Goonetilleke. Influence of the hierarchical structure of land use on metals, nutrients and organochlorine pesticides in urban river sediments. Ecological Engineering. 2020; 159 ():106123.
Chicago/Turabian StyleBuddhi Wijesiri; An Liu; Ayomi Jayarathne; Godfred Duodu; Godwin A. Ayoko; Lan Chen; Ashantha Goonetilleke. 2020. "Influence of the hierarchical structure of land use on metals, nutrients and organochlorine pesticides in urban river sediments." Ecological Engineering 159, no. : 106123.
Water scarcity, which is exacerbated by climate change, is a major challenge to ensure human well-being. Therefore, it is equally important to protect conventional water resources from degradation and at the same time to identify cost-effective alternatives with a low carbon footprint. In this regard, stormwater plays a key role as it is a largely underutilised resource for both potable and non-potable use. However, stormwater carries substantial loads of pollutants to receiving waters such as rivers. Unfortunately, the lack of comprehensive stormwater quality modelling strategies, which account for the effects of climate change, constrains the formulation of effective measures to improve the quality of stormwater. Currently, there is a significant knowledge gap in the merging of stormwater quality modelling and climate modelling. This paper critically reviews current stormwater quality modelling approaches (quantity and quality) and the role of climate modelling outputs in stormwater quality modelling. This is followed by the presentation of a robust framework to integrate the impacts of climate change with stormwater quality models.
Buddhi Wijesiri; Erick Bandala; An Liu; Ashantha Goonetilleke. A Framework for Stormwater Quality Modelling under the Effects of Climate Change to Enhance Reuse. Sustainability 2020, 12, 10463 .
AMA StyleBuddhi Wijesiri, Erick Bandala, An Liu, Ashantha Goonetilleke. A Framework for Stormwater Quality Modelling under the Effects of Climate Change to Enhance Reuse. Sustainability. 2020; 12 (24):10463.
Chicago/Turabian StyleBuddhi Wijesiri; Erick Bandala; An Liu; Ashantha Goonetilleke. 2020. "A Framework for Stormwater Quality Modelling under the Effects of Climate Change to Enhance Reuse." Sustainability 12, no. 24: 10463.
The Event Mean Concentration (EMC) is considered as a key analytical parameter for assessing the quality of stormwater. The conventional estimation methods to determine EMC do not necessarily address the variability associated with the hydrologic characteristics. Accordingly, this study was conducted to identify the potential hydrologic variables that can influence EMC and thereby to create a mathematical model to determine EMC using the hydrologic variables while incorporating the catchment as an influential factor. This paper introduces an innovative approach to estimate EMC of a runoff event using a stepwise multiple linear regression model. The model incorporates hydrologic variables together with their two-way interaction terms. The catchment was included in the model as a dummy variable. This allows identifying the variability of EMC between catchments. Model can reasonably predict the EMC with an overall prediction error of 0.811. The regression coefficients of the model specify that, maximum rainfall intensity is the most influential variable having a coefficient of 1.008, followed by the average intensity with a coefficient −0.586. The interaction term of rainfall depth and the antecedent dry period indicates that for a relatively small rainfall event (<5 mm), an optimum value of antecedent dry period exists that maximises the EMC. Subsequently, EMC was employed to define the first flush runoff as an alternative approach to the conventional approaches for determining the first flush. The dynamic mean concentration (DMCt), was introduced as a parameter for estimating the first flush using EMC. The maximum accumulated runoff volume such that, DMCt≥EMC was defined as the first flush runoff. It was found that residential catchments generate more intense first flush compared to catchments with totally impervious surface areas and thereby a significant pollutant load is transported within a small initial fraction of the runoff.f
Thamali Perera; James McGree; Prasanna Egodawatta; K.B.S.N. Jinadasa; Ashantha Goonetilleke. Catchment based estimation of pollutant event mean concentration (EMC) and implications for first flush assessment. Journal of Environmental Management 2020, 279, 111737 .
AMA StyleThamali Perera, James McGree, Prasanna Egodawatta, K.B.S.N. Jinadasa, Ashantha Goonetilleke. Catchment based estimation of pollutant event mean concentration (EMC) and implications for first flush assessment. Journal of Environmental Management. 2020; 279 ():111737.
Chicago/Turabian StyleThamali Perera; James McGree; Prasanna Egodawatta; K.B.S.N. Jinadasa; Ashantha Goonetilleke. 2020. "Catchment based estimation of pollutant event mean concentration (EMC) and implications for first flush assessment." Journal of Environmental Management 279, no. : 111737.
In this study, PAHs and their transformed PAH products (TPPs) in road dust were subjected to UV driven photolysis, and then quantified using simultaneous pressurized fluid extraction, and analysed using Shimadzu Triple Quadrupole GC/MS. The results of the analysis were used to investigate the robustness and reliability of 14 existing diagnostic ratios (DRs) and two newly proposed molecular DRs that are relevant for characterizing the sources of PAHs and TPPs. The influence of photolysis on the carcinogenic health risk posed to humans by these hazardous pollutants was then assessed. The findings indicated that the DRs segregated into stable, moderately stable and non-stable classes of source characteristics under the influence of photolysis. Only two of the existing DRs, namely, benzo(a)pyrene/benzo(ghi)perylene (BaP/BghiP) and total index exhibited consistent stability to photolysis, whilst fluoranthene/(fluoranthene + pyrene) (FRT/(FRT+PYR)) showed moderate stability. The two newly proposed DRs, naphthalene/1-nitronaphthalene (NAP/NNAP) and pyrene/(1-nitropyrene + 1-hydroxypyrene) (PYR/(1NPY+HPY)) were found to be highly reliable in post-emission source characterization. The cross-plots of the most stable DRs showed that traffic emissions is the primary source of PAHs, whilst post-emission photolysis is the secondary source of nitro-PAH (NPAH) TPPs. The percent resonance energy thermodynamic stability of the PAH pollutants does not exert any direct influence on the source characteristics of the DRs. Adults are more vulnerable to potential carcinogenic risks as a result of PAH and TPPs photolysis whereas negligible risk exist for children. This study contributes to a more reliable diagnosis of PAH and TPP sources and thus, to the regulatory mitigation of these hazardous pollutants thereby, promoting enhanced protection of human health and the environment.
Gustav Gbeddy; Prasanna Egodawatta; Ashantha Goonetilleke; Eric Akortia; Eric T. Glover. Influence of photolysis on source characterization and health risk of polycyclic aromatic hydrocarbons (PAHs), and carbonyl-, nitro-, hydroxy- PAHs in urban road dust. Environmental Pollution 2020, 269, 116103 .
AMA StyleGustav Gbeddy, Prasanna Egodawatta, Ashantha Goonetilleke, Eric Akortia, Eric T. Glover. Influence of photolysis on source characterization and health risk of polycyclic aromatic hydrocarbons (PAHs), and carbonyl-, nitro-, hydroxy- PAHs in urban road dust. Environmental Pollution. 2020; 269 ():116103.
Chicago/Turabian StyleGustav Gbeddy; Prasanna Egodawatta; Ashantha Goonetilleke; Eric Akortia; Eric T. Glover. 2020. "Influence of photolysis on source characterization and health risk of polycyclic aromatic hydrocarbons (PAHs), and carbonyl-, nitro-, hydroxy- PAHs in urban road dust." Environmental Pollution 269, no. : 116103.
The key challenge in social resilience assessment is to translate abstract and complex concepts to enable its measurement. Existing measures of social resilience indicators are problematic as these do not necessarily account for the multi-faceted and dynamic nature of the indicators. Therefore, innovative and reliable measurement approaches are required to improve the incorporation of social resilience measures in disaster management policy and practice. The adoption of a surrogate approach, which has received limited attention in a disaster management context, can help to overcome the conceptual challenges inherent in measuring such indicators by capturing key facets of the target indicator and facilitate robust social resilience measurement. This manuscript presents a set of potential surrogates for social resilience indicators identified in an exploratory research investigation. The data was collected using a case study approach utilising interviews with disaster practitioners and policy makers. The data analysis revealed six potential surrogates for each social resilience indicator. The identified potential surrogates provide a reliable measure of social resilience in policy and practice to devise appropriate strategies for enhancing social resilience by regularly monitoring and updating the resilience status using locally available administrative data. The potential surrogates identified to measure social resilience indicators can also be replicated with proper contextualisation in different geographic and hazard exposure settings.
A.M. Aslam Saja; Melissa Teo; Ashantha Goonetilleke; Abdul M. Ziyath. Assessing social resilience in disaster management. International Journal of Disaster Risk Reduction 2020, 52, 101957 .
AMA StyleA.M. Aslam Saja, Melissa Teo, Ashantha Goonetilleke, Abdul M. Ziyath. Assessing social resilience in disaster management. International Journal of Disaster Risk Reduction. 2020; 52 ():101957.
Chicago/Turabian StyleA.M. Aslam Saja; Melissa Teo; Ashantha Goonetilleke; Abdul M. Ziyath. 2020. "Assessing social resilience in disaster management." International Journal of Disaster Risk Reduction 52, no. : 101957.
A sensitive and recyclable plasmonic nickel foam sensor has been developed for surface-enhanced Raman spectroscopy (SERS). A simple electrochemical method was used to deposit flower-shaped gold nanostructures onto nickel foam substrate. The high packing of the gold nanoflowers onto the nickel foam led to a high enhancement factor (EF) of 1.6 × 1011. The new SERS sensor was utilized for the direct determination of the broad-spectrum β-lactam carbapenem antibiotic meropenem in human blood plasma down to one pM. The sensor was also used in High Performance Liquid Chromatography (HPLC)-SERS assembly to provide fingerprint identification of meropenem in human blood plasma. Moreover, the SERS measurements were reproducible in aqueous solution and human blood plasma (RSD = 5.5%) and (RSD = 2.86%), respectively at 200 µg/mL (n = 3), and successfully recycled using a simple method, and hence, used for the repeated determination of the drug by SERS. Therefore, the new sensor has a strong potential to be applied for the therapeutic drug monitoring of meropenem at points of care and intensive care units.
Saiqa Muneer; Daniel K. Sarfo; Godwin A. Ayoko; Nazrul Islam; Emad L. Izake. Gold-Deposited Nickel Foam as Recyclable Plasmonic Sensor for Therapeutic Drug Monitoring in Blood by Surface-Enhanced Raman Spectroscopy. Nanomaterials 2020, 10, 1756 .
AMA StyleSaiqa Muneer, Daniel K. Sarfo, Godwin A. Ayoko, Nazrul Islam, Emad L. Izake. Gold-Deposited Nickel Foam as Recyclable Plasmonic Sensor for Therapeutic Drug Monitoring in Blood by Surface-Enhanced Raman Spectroscopy. Nanomaterials. 2020; 10 (9):1756.
Chicago/Turabian StyleSaiqa Muneer; Daniel K. Sarfo; Godwin A. Ayoko; Nazrul Islam; Emad L. Izake. 2020. "Gold-Deposited Nickel Foam as Recyclable Plasmonic Sensor for Therapeutic Drug Monitoring in Blood by Surface-Enhanced Raman Spectroscopy." Nanomaterials 10, no. 9: 1756.
The design of vertical subsurface flow (VSSF) constructed wetlands (CWs) uses kinetic models to calculate the area based on the kinetic reaction rate constant (k) specific to local environmental conditions and target pollutants. Currently, kinetic modelling does not fully account for the impact of the hydraulic loading rate (HLR), which influences the wetland performance. This study used four experimental VSSF CWs operated at HLRs of 5, 10, 20 and 40 cm/day to investigate the applicability of three first order kinetic models combining plug-flow and continuous stirred tank reactor (CSTR) flow patterns. The target pollutants were BOD5, NH4+ and NO3-. For each pollutant, estimated k values varied between different HLRs and between plug flow and CSTR models. Assessment of uncertainty in kinetic modelling showed that all three models exhibit a similar trend in predicting the concentrations of BOD5 and NH4+ at 5–20 cm/day HLRs. A substantial removal of BOD5 (>88 %) and NH4+ (>70 %) were found for the investigated HLRs, although NO3- removal was not satisfactory. The HLR had a positive impact on mass removal rates (MRRs) for BOD5 and NH4+. Accordingly, 20 cm/day was deemed as the highest viable HLR for designing effective VSSF wetlands for the removal of BOD5 and NH4+. All three models can be employed to design VSSF wetlands at 20 cm/day HLR to treat BOD5 using k values of 0.352 (k-C), 0.380 (k-C*) and 0.996 (CSTR) m/day and to treat NH4+ using k values of 0.170 (k-C), 0.173 (k-C*) and 0.273 (CSTR) m/day.
G.M.P.R. Weerakoon; K.B.S.N. Jinadasa; Jagath Manatunge; Buddhi Wijesiri; Ashantha Goonetilleke. Kinetic modelling and performance evaluation of vertical subsurface flow constructed wetlands in tropics. Journal of Water Process Engineering 2020, 38, 101539 .
AMA StyleG.M.P.R. Weerakoon, K.B.S.N. Jinadasa, Jagath Manatunge, Buddhi Wijesiri, Ashantha Goonetilleke. Kinetic modelling and performance evaluation of vertical subsurface flow constructed wetlands in tropics. Journal of Water Process Engineering. 2020; 38 ():101539.
Chicago/Turabian StyleG.M.P.R. Weerakoon; K.B.S.N. Jinadasa; Jagath Manatunge; Buddhi Wijesiri; Ashantha Goonetilleke. 2020. "Kinetic modelling and performance evaluation of vertical subsurface flow constructed wetlands in tropics." Journal of Water Process Engineering 38, no. : 101539.
This study investigated the removal of Acetaminophen (ACT) using biochars having different physicochemical characteristics. Biochars subjected to post-pyrolysis heat-treatment at 300°C for different treatment times (0, 3.5, 8 and 24 h) were used. The resulting biochars were characterized using FTIR and X-ray diffraction spectroscopy. Experiments for ACT adsorption with different biochars loads (0.0, 0.05, 1, and 2 g L-1) were performed. Using the best performing material, ACT adsorption was investigated for additional biochar loads (4.0, and 6.0 g L-1) and experiments to test the effect of ionic strength were undertaken for different ions (chloride, carbonate, and nitrate) at three different concentrations (0.0, 1.0, 5.0 mM). The results showed that the changes to the surface of the thermally treated biochars increased the adsorption of ACT. The changes in the amount of oxygen-containing functional groups on the surface of the modified biochars (e.g., C=O from 47.8 a.u. to 152 a.u. in the untreated and thermally treated biochars, respectively), as well as modifications to their crystalline structure are considered to be the reason for the observed improvement. Adsorption isotherm and kinetic models suggest the generation of an adsorbate monolayer and chemisorption as the rate-limiting step. The different anions tested were found to have a significant influence on ACT adsorption, related to their electronegativity and steric effect, as confirmed by the multivariate analysis.
Adam M. Clurman; Oscar M. Rodríguez-Narvaez; Ayomi Jayarathne; Gehan De Silva; Mahinda Ranasinghe; Ashantha Goonetilleke; Erick R. Bandala. Influence of surface hydrophobicity/hydrophilicity of biochar on the removal of emerging contaminants. Chemical Engineering Journal 2020, 402, 126277 .
AMA StyleAdam M. Clurman, Oscar M. Rodríguez-Narvaez, Ayomi Jayarathne, Gehan De Silva, Mahinda Ranasinghe, Ashantha Goonetilleke, Erick R. Bandala. Influence of surface hydrophobicity/hydrophilicity of biochar on the removal of emerging contaminants. Chemical Engineering Journal. 2020; 402 ():126277.
Chicago/Turabian StyleAdam M. Clurman; Oscar M. Rodríguez-Narvaez; Ayomi Jayarathne; Gehan De Silva; Mahinda Ranasinghe; Ashantha Goonetilleke; Erick R. Bandala. 2020. "Influence of surface hydrophobicity/hydrophilicity of biochar on the removal of emerging contaminants." Chemical Engineering Journal 402, no. : 126277.
Recombinant human erythropoietin (rHuEPO) is an important hormone drug that is used to treat several medical conditions.
Mahnaz D. Gholami; Frederick Theiss; Prashant Sonar; Godwin A. Ayoko; Emad L. Izake. Rapid and selective detection of recombinant human erythropoietin in human blood plasma by a sensitive optical sensor. The Analyst 2020, 145, 5508 -5515.
AMA StyleMahnaz D. Gholami, Frederick Theiss, Prashant Sonar, Godwin A. Ayoko, Emad L. Izake. Rapid and selective detection of recombinant human erythropoietin in human blood plasma by a sensitive optical sensor. The Analyst. 2020; 145 (16):5508-5515.
Chicago/Turabian StyleMahnaz D. Gholami; Frederick Theiss; Prashant Sonar; Godwin A. Ayoko; Emad L. Izake. 2020. "Rapid and selective detection of recombinant human erythropoietin in human blood plasma by a sensitive optical sensor." The Analyst 145, no. 16: 5508-5515.
The deposition and the re-suspension of particulate matter (PM) in urban areas are the key processes that contribute not only to stormwater pollution, but also to air pollution. However, investigation of the deposition and the re-suspension of PM is challenging because of the difficulties in distinguishing between the resuspended and the deposited PM. This study created two Bayesian Networks (BN) models to explore the deposition and the re-suspension of PM as well as the important influential factors. The outcomes of BN modelling revealed that deposition and re-suspension of PM10 occurred under both, high-traffic and low-traffic conditions, and the re-suspension of PM2.5 occurred under low-traffic conditions. The deposition of PM10 under low-volume traffic condition is 1.6 times higher than under high-volume traffic condition, which is attributed to the decrease in PM10 caused by relatively higher turbulence under high-volume traffic conditions. PM10 is more easily resuspended from road surfaces compared to PM2.5 as the particles which larger than the thickness of the laminar airflow over the road surface are more easily removed from road surfaces. The increase in wind speed contributes to the increase in PM build-up by transporting particulates from roadside areas to the road surfaces and the airborne PM2.5 and PM10 increases with the increase in relative humidity. The study outcomes provide a step improvement in the understanding of the transfer processes of PM2.5 and PM10 between atmosphere and urban road surfaces, which in turn will contribute to the effective design of mitigation measures for urban stormwater and air pollution.
Tong Wei; Buddhi Wijesiri; Yingxia Li; Ashantha Goonetilleke. Particulate matter exchange between atmosphere and roads surfaces in urban areas. Journal of Environmental Sciences 2020, 98, 118 -123.
AMA StyleTong Wei, Buddhi Wijesiri, Yingxia Li, Ashantha Goonetilleke. Particulate matter exchange between atmosphere and roads surfaces in urban areas. Journal of Environmental Sciences. 2020; 98 ():118-123.
Chicago/Turabian StyleTong Wei; Buddhi Wijesiri; Yingxia Li; Ashantha Goonetilleke. 2020. "Particulate matter exchange between atmosphere and roads surfaces in urban areas." Journal of Environmental Sciences 98, no. : 118-123.