Browsing by Author "Campo Moreno, Pablo"
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Item Open Access Assessing environmental drivers of fluoride mobilization in groundwater under increased loading of dissolved organic matter from managed aquifer recharge (MAR) Item(Cranfield University, 2022-12-01 15:51) Parker, Alison; Campo Moreno, Pablo; Le Corre Pidou, KristellGeogenic fluoride contamination of groundwater is common in many semi-arid regions, and the impact of managed aquifer recharge (MAR) on increased mobilization of fluoride to the water in these regions is a concern. This work used saturated column experiments to explore the aqueous and mineralogical environmental drivers of fluoride mobilization and how they interact with increased loading of dissolved organic matter (DOM) from infiltrated runoff collected by MAR structures. Groundwater alkalinity was identified as the dominating driver of fluoride mobilization, resulting in increased dissolution of fluorite under all mineral matrix compositions. The influx of a 20 mg/L load of DOM somewhat reduced the mobilization of fluoride from the solid matrix under alkaline conditions, but otherwise did not influence fluorite dissolution compared to unloaded conditions. Environmental drivers were therefore identified as important predictors of fluoride mobilization at groundwater extraction sites, whereas the additional load of DOM to the groundwater resulting from MAR structures does not appear to increase fluoride concentration in the groundwater.Item Open Access Biotransformation and sorption of trace organic compounds in biological nutrient removal treatment systems(Elsevier, 2018-05-29) Lakshminarasimman, Narasimman; Quiñones, Oscar; Vanderford, Brett J.; Campo Moreno, Pablo; Dickenson, Eric V.; McAvoy, Drew C.This study determined biotransformation rates (kbio) and sorption-distribution coefficients (Kd) for a select group of trace organic compounds (TOrCs) in anaerobic, anoxic, and aerobic activated sludge collected from two different biological nutrient removal (BNR) treatment systems located in Nevada (NV) and Ohio (OH) in the United States (US). The NV and OH facilities operated at solids retention times (SRTs) of 8 and 23 days, respectively. Using microwave-assisted extraction, the biotransformation rates of the chosen TOrCs were measured in the total mixed liquor. Sulfamethoxazole, trimethoprim, and atenolol biotransformed in all three redox regimes irrespective of the activated sludge source. The biotransformation of N, N-diethyl-3-methylbenzamide (DEET), triclosan, and benzotriazole was observed in aerobic activated sludge from both treatment plants; however, anoxic biotransformation of these three compounds was seen only in anoxic activated sludge from NV. Carbamazepine was recalcitrant in all three redox regimes and both sources of activated sludge. Atenolol and DEET had greater biotransformation rates in activated sludge with a higher SRT (23 days), while trimethoprim had a higher biotransformation rate in activated sludge with a lower SRT (8 days). The remaining compounds did not show any dependence on SRT. Lyophilized, heat inactivated sludge solids were used to determine the sorption-distribution coefficients. Triclosan was the most sorptive compound followed by carbamazepine, sulfamethoxazole, DEET, and benzotriazole. The sorption-distribution coefficients were similar across redox conditions and sludge sources. The biotransformation rates and sorption-distribution coefficients determined in this study can be used to improve fate prediction of the target TOrCs in BNR treatment systems.Item Open Access Data: Hydrodynamics (Reynolds number) determine scaling, nucleation and crystal growth kinetics in membrane distillation crystallisation(Cranfield University, 2023-09-05 16:18) McAdam, Ewan; Jikazana, Aphiwe; Campo Moreno, PabloDataset for journal article "Hydrodynamics (Reynolds number) determine scaling, nucleation and crystal growth kinetics in membrane distillation crystallisation"Item Open Access Development of a testing protocol for oil solidifier effectiveness evaluation(Springer Verlag, 2016-02-04) Sundaravadivelu, Devi; Suidan, Makram T.; Venosa, Albert D.; Rosales, Pablo I.; Campo Moreno, Pablo; Conmy, Robyn N.Chemical countermeasures for oil spill remediation have to be evaluated and approved by the U.S. Environmental Protection Agency before they may be used to remove or control oil discharges. Solidifiers are chemical agents that change oil from a liquid to a solid by immobilizing the oil and bonding the liquid into a solid carpet-like mass with minimal volume increase. Currently, they are listed as Miscellaneous Oil Spill Control Agent in the National Contingency Plan and there is no protocol for evaluating their effectiveness. An investigation was conducted to test the oil removal efficiency of solidifiers using three newly developed testing protocols. The protocols were qualitatively and quantitatively evaluated to determine if they can satisfactorily differentiate effective and mediocre products while still accounting for experimental error. The repeatability of the three protocols was 15.9, 5.1, and 2.7 %. The protocol with the best performance involved measuring the amount of free oil remaining in the water after the solidified product was removed using an ultraviolet–visible spectrophotometer and it was adopted to study the effect of solidifier-to-oil mass ratio, mixing energy, salinity, and beaker size (i.e., area affected by the spill) on solidifier efficiency. Analysis of Variances were performed on the data collected and results indicated that the beaker size increased spreading, which reduced removal efficiency. Mixing speed appears to impart a ceiling effect with no additional benefit provided by the highest level over the middle level. Salinity was found to be mostly an insignificant factor on performance.Item Open Access Diagnostic strategy and risk assessment framework for complex chemical mixtures(2018-10) Cipullo, Sabrina; Coulon, Frederic; Campo Moreno, PabloEnvironmental contamination comprises a complex mixture of both organic and inorganic contaminants. Understanding their distribution, behaviour and chemical interactions provides the evidence necessary to make informed decision and implement robust remediation strategies. However most of the current risk assessment frameworks, used to manage land contamination, are based on the total contaminant concentration rather than the concentration likely to pose significant risk, the bioavailable concentration. Further to this, the exposure assessments embedded within the frameworks do not explicitly address the partitioning and bioavailability of chemical mixtures. This inability may contribute to an overestimation of both the eco-toxicological effects of the fractions and their mobility in air and water; leading to an overestimation of health and environmental effects. In turn, this may limit the efficacy of the risk assessment frameworks to inform targeted and proportionate remediation strategies. The aim of this PhD study was to address this gap by delivering an integrated risk assessment framework for sites contaminated with complex chemical mixtures. Specifically, this PhD study investigated the fate and behaviour of complex mixtures of petroleum hydrocarbons, metals and metalloids in soils and its implication for partitioning, bioavailability and risk assessment through a 12 month mesocosms study. Further to this, an integrated approach, where contaminants bioavailability and distribution changes along with a range of microbiological indicators and ecotoxicological bioassays, was used to provide multiple lines of evidence to support the risk characterisation and assess the remediation end-point over a 6 month study. From the empirical data obtained from the two mesocosm studies, two Machine Leaning (ML) approaches have been developed to provide a quick and reliable tool to assess multi-contaminated sites with Visible and Near-Infrared Spectroscopy (Vis-NIRS), and to predict bioavailability and toxicity changes occurring during bioremediation. Overall this PhD study shed light on the behaviour of bioavailability, and toxicity of complex chemical mixtures in soils genuinely contaminated. This was supported through a comprehensive and integrated analytical framework providing the necessary lines of evidence to evaluate the implications for risk assessment and identify the end point remediation. The developed framework can significantly help to identify optimal remediation strategies and contribute to change the over-conservative nature of the current risk assessments.Item Open Access Distribution of trace metals (Cu, Pb, Ni, Zn) between particulate, colloidal and truly dissolved fractions in wastewater treatment(Elsevier, 2017-02-07) Hargreaves, Andrew J.; Dotro, Gabriela; Campo Moreno, PabloThe distribution of Cu, Pb, Ni and Zn between particulate, colloidal and truly dissolved size fractions in wastewater from a trickling filter treatment plant was investigated. Samples of influent, primary effluent, humus effluent, final effluent and sludge holding tank returns were collected and separated into particulate (i.e. > 0.45 μm), colloidal (i.e. 1 kDa to 0.45 μm), and truly dissolved (i.e. < 1 kDa) fractions using membrane filters. In the influent, substantial proportions of Cu (60%), Pb (67%), and Zn (32%) were present in the particulate fraction which was removed in conjunction with suspended particles at the works in subsequent treatment stages. In final effluent, sizeable proportions of Cu (52%), Pb (32%), Ni (44%) and Zn (68%) were found within the colloidal size fraction. Calculated ratios of soluble metal to organic carbon suggest the metal to be adsorbed to or complexed with non-humic macromolecules typically found within the colloidal size range. These findings suggest that technologies capable of removing particles within the colloidal fraction have good potential to enhance metals removal from wastewater.Item Open Access ENERWATER – A standard method for assessing and improving the energy efficiency of wastewater treatment plants(Elsevier, 2019-03-21) Longo, Stefano; Mauricio-Iglesias, Miguel; Soares, Ana; Campo Moreno, Pablo; Fatone, Francesco; Eusebi, Anna L.; Akkersdijk, E; Stefani, L.; Hospido, AlmudenaThis paper describes the first methodology specifically tailored to estimate energy efficiency at wastewater treatment plants (WWTPs). Inspired by the cycle of continuous improvement, the method (i) precisely defines the concept of energy efficiency in WWTPs, (ii) proposes systematic and comparable ways to measure it, and (iii) allows benchmarking and diagnosing energy hotspots. The methodology delivers an aggregated measure of the WWTP energy efficiency defined as the Water Treatment Energy Index, a single energy label that uses universally known illustrations enabling wide communication of standardized information on the WWTP energy status. The accuracy, reproducibility and generality of the methodology were validated by a widespread energy benchmarking method, and a case study is presented to show its capabilities. By promoting dialogue towards the creation of a specific European Standard, the actions accomplished by the H2020 Coordination Support Action ENERWATER should positively contribute to improving the exchange of information on energy saving actions and results between wastewater utilities and towards other stakeholders.Item Open Access Engineering biological wastewater treatment for the removal of hazardous chemicals.(Cranfield University, 2019-10) Mensah, Lawson; Campo Moreno, Pablo; Scrimshaw, MarkThe European Union’s Environmental Quality Standards (EQS) continue to be stringent with regards to discharge of hazardous chemicals (HCs) (mainly organic micropollutants) from wastewater treatment plants (WWTPs). The strict limits are driven by the growing interest in wastewater reuse, evidence of feminisation of male aquatic species and bioaccumulation of HCs in water-based biota. WWTPs are the last barrier to these chemicals getting into the environment from homes, institutions and industries and therefore optimisation of existing WWTPs is critical. The operational conditions of the WWTPs such as solid retention time (SRT), hydraulic retention time (HRT), dissolved oxygen (DO) concentration and seasonal temperature variations have been proven to influence the removal of these HCs and also affect the microbial/bacterial diversity in WWTPs. This study therefore aimed to find the missing link in the literature, which is to seek the relationship between the microbial/bacterial diversity or abundance and HCs removal in WWTPs. A pilot-scale study was conducted to analyse the microbial and bacterial diversity using phospholipids fatty acid and 16S rRNA analysis respectively at 3, 10 and 27 d SRT (at constant 8 h HRT) and then repeated at a fixed 27 d SRT while HRT varied at 8, 16 and 24 h. The concentrations of nonylphenols and estrogens in the influent and effluent were also analysed using LC-MS/MS to determine the plant’s chemical removal efficiency. The results showed that raising SRT (from 3 to 27 d) and HRT (from 8 to 24 h) increased bacterial diversity by 2.7 times and increased the removal of EE2 by 11%. The pilot-scale also revealed 32 novel positive correlations between bacterial genera abundance and HCs removal. The abundances of Hyphomicrobium, Mesorhizobium, Planctomyces, and Rhizomicrobium positively correlated with the removals of estrogens (E1, E2 and E3) and with nonylphenols (NP₂ EC, NP ₅EO) at r- values >0.7. The experiment was repeated by surveying the bacterial diversity in 12 full-scale activated sludge plants (ASPs) operating at varying DO levels, SRTs (4.9 to 22.3 d), HRTs (6.2 to 26.6 h) and temperature (10.6 to 20.3 ˚C). The concentrations of 26 micropollutants (analgesics, antibiotics, anti-depressants, beta-blockers, estrogens, flame retardants etc.) were also analysed in the influent and effluent. The results showed that bacterial diversity in the full- scale reactor differed from that of the pilot-scale plant. Euclidean distance matrix shows that temperature (p<0.005) was the most influential parameter in chemical removal and bacterial diversity. SRT and HRT were also important in bacterial diversity and HC removal but not in every ASP. Removal of HC followed a pseudo first order kinetics with metformin and ibuprofen achieving >98% removals. DO concentration did not show any effect due to lack of variation across the WWTPs. Once again, some novel correlations between bacterial genera abundance and chemical removal were found. The abundances of Candidatus Accumulibacter (a phosphate accumulating bacteria capable of denitrification) and Nitrosomonas (nitrite-oxidising bacteria) correlate positively with the removal of trixylenyl phosphate (flame retardant) at R>0.7. Anaeromyxobacter dehalogenans abundance also correlates positively with the removal of erythromycin. This work has shown that process parameters do influence both bacterial diversity and hazardous chemical removal, and there are correlations between bacteria taxa abundance and HCs removal. This knowledge will be vital in the discussion on improving existing activated sludge plants achieve better chemical removal and it will also be the foundation for future research into correlations of bacterial taxa abundance with chemical removal in the ASP reactor.Item Open Access Estimation of Groundwater Recharge in Semi-Arid Regions under Variable Land Use and Rainfall Conditions.(Cranfield University, 2020-09-17 16:47) Yadav, Basant; Parker, Alison; Le Corre Pidou, Kristell; Campo Moreno, PabloSoil water balance analysis and recharge estimation for a semi-arid region of Lapodiya watershed in 2019-20.Item Open Access Estimation of groundwater recharge in semiarid regions under variable land use and rainfall conditions: a case study of Rajasthan, India(PLOS (Public Library of Science), 2023-03-22) Yadav, Basant; Parker, Alison; Sharma, Anupma; Sharma, Rakesh; Krishan, Gopal; Kumar, Suraj; Le Corre Pidou, Kristell; Campo Moreno, PabloIn the semiarid regions of India, the annual rainfall is very low (~650 mm) and erratic; hence groundwater recharge is vital to support crops, especially in the winter season. For groundwater budgeting it is essential to consider how groundwater recharge is affected by both land-use and rainfall distribution. This study used a soil water balance approach, considering hydrological, meteorological, hydrogeological and crop information to understand the recharge process in semiarid regions. The approach was used at a sub-watershed scale where farmers grow rainfed and irrigated crops. Delayed recharge response on the water table was considered to estimate actual recharge, which closely matches the observed water levels in the field. The recharge estimated in rainfed agricultural lands, rainfed-irrigated agricultural lands, and barren lands was 29%, 17%, and 31% of the total inflow.Item Open Access Hydrodynamics (Reynolds number) determine scaling, nucleation and crystal growth kinetics in membrane distillation crystallisation(Elsevier, 2023-07-08) Jikazana, Aphiwe; Campo Moreno, Pablo; McAdam, EwanReynolds number (Re) has been previously related to several scaling mitigation and crystallisation strategies that offer distinct hypotheses for how Re may regulate the kinetics of nucleation and crystal growth in membrane crystallisation. Such ambiguity has arisen from the present inability to discretely characterise induction time in membrane systems. This study therefore introduces techniques for the detection of induction time, with measurements used to develop a modified power-law relation between nucleation rate and supersaturation to establish how Re can be used to adjust nucleation kinetics. Increasing Re enhanced mass and heat transfer processes which raised permeate flux. The interfacial supersaturation set by the increase in flux, also modified the supersaturation rate at induction for crystals formed in the bulk solution, providing the first direct evidence that it is the supersaturation level set within the boundary layer which controls primary nucleation in the bulk solution. Bulk nucleation rate can therefore be adjusted in proportion to Re. While the extent of scaling was also determined by the interfacial supersaturation set by Re, its formation was shown to be more dependent on the interfacial diffusion coefficient which regulates solute backtransport and the activation energy for nucleation. Through this work we suggest that the nucleation mechanisms underlying scale formation and bulk crystallisation are distinct. The regulation of nucleation rate in the bulk solution by Re is described analytically through classical nucleation theory, while scaling can be mitigated through operation below a critical threshold supersaturation value that determines the rate and type of scaling that prevails. These seemingly distinct strategies can be combined through modifications to T and dT with Re to suppress scaling and offer refined control over the kinetics of nucleation and crystal growth.Item Open Access Impact of the Oxford canal on water quality and ecological status of the River Cherwell.(Cranfield University, 2021-09) Dowdeswell-Downey, Luke; Grabowski, Robert; Campo Moreno, PabloGood quality water provides numerous ecosystem services and it is a legal requirement of the Water Framework Directive for all waterbodies to be achieving good status. Achieving good water quality and ecological status remains a critical issue throughout most waterbodies within the UK. Waterbodies can have an impact on one another, however, determining the impact of tributaries and canal interactions on rivers remains a challenge. This study aims to investigate whether the Oxford canal has had a negative impact upon water quality and ecological status of the River Cherwell. New water quality and sediment samples were collected, upstream and downstream of where the river and canal interact at two sections at 16 sampling locations. Historical invertebrate data was examined at three locations; upstream, between and downstream of these two sections along the River Cherwell and compared to the nearby River Windrush, which does not interact with any canals. Results showed no statistical decreases in river water quality downstream of where the canal joins the river. Conversely, there was evidence that interaction with the canal water may have decreased river nutrient levels, such as nitrate, by a dilution effect. Furthermore, mixing with river water may have significantly increased orthophosphate and conductivity in the canal (p< 0.05). Similarly, invertebrate data showed no negative impact from the canal on the river in terms of taxa richness, BMWP, ASPT, and diversity indices. However, results suggested that the River Cherwell has had higher invertebrate metrics and indices when compared to the River Windrush. Overall, this study found no evidence to indicate that the Oxford canal negatively impacted water quality and ecological status of the River Cherwell.Item Open Access Improving Energy Efficiency in Wastewater Treatment. Identification of Key Parameters and Key Performance Indicators(Cranfield University, 2018-12-05 09:11) Campo Moreno, PabloIn this presentation we propose to identify relevant parameters (key performance indicators, KPIs) that better describe the performance of a given treatment stage along with its corresponding energy demand. The final goal for compiling KPIs is the calculation of the Water Treatment Energy Index. This index evaluates the energy efficency in wastewater treatment plants and will allow one to readily compare energy utilization from different plants in a systematic way.Item Open Access Insights into mixed contaminants interactions and its implication for heavy metals and metalloids mobility, bioavailability and risk assessment(Elsevier, 2018-07-18) Cipullo, C.; Snapir, B.; Tardif, S.; Campo Moreno, Pablo; Prpich, George; Coulon, FredericMobility of heavy metals at contaminated sites is mainly influenced by the soil physicochemical properties and environmental conditions, therefore assessing heavy metals (HMs) and metalloids fractionation can provide insights into their potential risk and the mechanisms that regulate bioavailability. A 12-months mesocosms experiment was setup to investigate the effect of physicochemical factors (pH, moisture, and temperature) and weathering (time) on HMs and metalloids fractionation in three different multi-contaminated soil matrices (low, medium, and high contamination) collected from a soil treatment facility located in the United Kingdom, and two rural contaminated soil samples. The study demonstrates that even though Pb and Zn were found associated with the exchangeable fraction in the soil with the highest contamination (total average Pb 3400 mg/kg, and total average Zn 2100 mg/kg in Soil C), neither the condition applied nor the weathering caused an increase in their mobility. Although it was expected that lower pH (4.5) would favours the dissociation of HMs and metalloids, no significant differences were observed, potentially due to the initial alkaline pH of the genuine-contaminated soil samples. The results show that even though total concentration of Pb, Cu, and Zn exceed the soil standards and guideline values, HMs were predominantly associated with the non-exchangeable fraction, while only 5% were dissolved in the pore water fraction (potentially bioavailable). In addition, the mobility and bioavailability of HMs remained constant over the 12 months monitoring, suggesting that these soils pose negligible risk to the environment.Item Open Access Linking bioavailability and toxicity changes of complex chemicals mixture to support decision making for remediation endpoint of contaminated soils(Elsevier, 2018-09-27) Cipullo, Sabrina; Negrin, I.; Claveau, Leila; Snapir, Boris; Tardif, S.; Pulleyblank, C.; Prpich, George; Campo Moreno, Pablo; Coulon, FredericA six-month laboratory scale study was carried out to investigate the effect of biochar and compost amendments on complex chemical mixtures of tar, heavy metals and metalloids in two genuine contaminated soils. An integrated approach, where organic and inorganic contaminants bioavailability and distribution changes, along with a range of microbiological indicators and ecotoxicological bioassays, was used to provide multiple lines of evidence to support the risk characterisation and assess the remediation end-point. Both compost and biochar amendment (p = 0.005) as well as incubation time (p = 0.001) significantly affected the total and bioavailable concentrations of the total petroleum hydrocarbons (TPH) in the two soils. Specifically, TPH concentration decreased by 46% and 30% in Soil 1 and Soil 2 amended with compost. These decreases were accompanied by a reduction of 78% (Soil 1) and 6% (Soil 2) of the bioavailable hydrocarbons and the most significant decrease was observed for the medium to long chain aliphatic compounds (EC16–35) and medium molecular weight aromatic compounds (EC16–21). Compost amendment enhanced the degradation of both the aliphatic and aromatic fractions in the two soils, while biochar contributed to lock the hydrocarbons in the contaminated soils. Neither compost nor biochar affected the distribution and behaviour of the heavy metals (HM) and metalloids in the different soil phases, suggesting that the co-presence of heavy metals and metalloids posed a low risk. Strong negative correlations were observed between the bioavailable hydrocarbon fractions and the ecotoxicological assays suggesting that when bioavailable concentrations decreased, the toxicity also decreased. This study showed that adopting a combined diagnostic approach can significantly help to identify optimal remediation strategies and contribute to change the over-conservative nature of the current risk assessments thus reducing the costs associated with remediation endpoint.Item Open Access Magnetically recoverable TiO2-WO3 photocatalyst to oxidize bisphenol A from model wastewater under simulated solar light(Springer, 2016-09-27) Dominguez, S.; Huebra, M.; Han, C.; Campo Moreno, Pablo; Nadagouda, M. N.; Rivero, M. J.; Ortiz, I.; Dionysiou, D. D.A novel magnetically recoverable, visible light active TiO2-WO3 composite (Fe3O4@SiO2@TiO2-WO3) was prepared to enable the photocatalyst recovery after the degradation of bisphenol A (BPA) under simulated solar light. For comparison, the photocatalytic activity of other materials such as non-magnetic TiO2-WO3, Fe3O4@SiO2@TiO2, TiO2, and the commercial TiO2 P25 was also evaluated under the studied experimental conditions. The structure and morphology of the synthesized materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), and electron dispersion spectroscopy (EDS). Moreover, Brunauer-Emmett-Teller (BET) surface area and magnetic properties of the samples were determined. The Fe3O4@SiO2@TiO2-WO3 and TiO2-WO3 led to a BPA degradation of 17.50 and 27.92 %, respectively, after 2 h of the simulated solar light irradiation. Even though their activity was lower than that of P25, which degraded completely BPA after 1 h, our catalysts were magnetically separable for their further reuse in the treatment. Furthermore, the influence of the water matrix in the photocatalytic activity of the samples was studied in municipal wastewater. Finally, the identification of reaction intermediates was performed and a possible BPA degradation pathway was proposed to provide a better understanding of the degradation process.Item Open Access The multiple uses of water derived from managed aquifer recharge systems in Kenya and India(IWA, 2022-01-19) Parker, Alison H.; Nyangoka, Justus; Rodrigues, Inês; Yadav, B.; Le Corre Pidou, Kristell; Campo Moreno, Pablo; Quinn, Ruth‘Multiple-use services’ (MUS) takes into account the fact that households use water for both domestic and for productive uses. This paper is the first to determine how managed aquifer recharge (MAR) systems are a form of MUS. Two cases were studied in India and in Kenya. In the Kenyan case, sand dams are the form of MAR, and in India check dams and infiltration ponds of various scales are used. Through observations, interviews, and water quality data, it is possible to describe how the communities access the water from these infrastructures in multiple ways for different uses, according to their water needs and the characteristics of the different access points. MAR involves harvesting rainwater and retaining run-off water into the dry season thus increasing the amount of available water and enabling diversification of water uses. It should therefore be considered as an option by water managers aiming to develop water resources meeting both the domestic and productive needs of communities.Item Open Access A multi‐component method to determine pesticides in surface water by liquid‐chromatography tandem quadrupole mass spectrometry(Wiley, 2017-06-15) Ramos, Andre; Cosgrove, Stephanie; Villa, Raffaella; Jefferson, Bruce; Campo Moreno, Pablo; Jarvis, Peter; Whelan, M. J.; Guymer, I.Pesticide pollution of surface water is a major concern in many agricultural catchments The development of rapid and accurate methods for determining pesticide concentrations in water samples is, therefore, important. Here we describe a method for the simultaneous analysis of six pesticides (metaldehyde, quinmerac, carbetamide, metazachlor, propyzamide and pendimethalin) in natural waters by direct aqueous injection with liquid chromatography-tandem mass spectrometry. The method validation showed good linearity from 0.2 to 50.0 µg/L with correlation coefficients between 0.995 and 0.999. Method accuracy ranged from 84 to 100% and precision Relative standard deviation (RSD) from 4 to 15%. The limits of detection for the targeted pesticides ranged from 0.03 to 0.36 µg/L. No significant matrix effects on quantification were observed (t-test). The method was tested on water samples from a small arable catchment in eastern England. Peak concentrations for the determinands ranged from 1 to 10 µg/L.Item Open Access Predicting bioavailability change of complex chemical mixtures in contaminated soils using visible and near-infrared spectroscopy and random forest regression(Nature Publishing Group, 2019-03-14) Cipullo, S.; Nawar, S.; Mouazen, A. M.; Campo Moreno, Pablo; Coulon, FredericA number of studies have shown that visible and near infrared spectroscopy (VIS-NIRS) offers a rapid on-site measurement tool for the determination of total contaminant concentration of petroleum hydrocarbons compounds (PHC), heavy metals and metalloids (HM) in soil. However none of them have yet assessed the feasibility of using VIS-NIRS coupled to random forest (RF) regression for determining both the total and bioavailable concentrations of complex chemical mixtures. Results showed that the predictions of the total concentrations of polycyclic aromatic hydrocarbons (PAH), PHC, and alkanes (ALK) were very good, good and fair, and in contrast, the predictions of the bioavailable concentrations of the PAH and PHC were only fair, and poor for ALK. A large number of trace elements, mainly lead (Pb), aluminium (Al), nickel (Ni), chromium (Cr), cadmium (Cd), iron (Fe) and zinc (Zn) were predicted with very good or good accuracy. The prediction results of the total HMs were also better than those of the bioavailable concentrations. Overall, the results demonstrate that VIS-NIR DRS coupled to RF is a promising rapid measurement tool to inform both the distribution and bioavailability of complex chemical mixtures without the need of collecting soil samples and lengthy extraction for further analysis.Item Open Access Predicting bioavailability change of complex chemical mixtures in contaminated soils using visible and near-infrared spectroscopy and random forest regression em(Cranfield University, 2018-12-04 12:08) Coulon, Frederic; Cipullo, Sabrina; Campo Moreno, Pablo; Mouazen, Abdul; Nawar, SaidRaw data for total and bioavailable concentrations of petroleum hydrocarbons compounds, heavy metals and metalloids in the five soils.Spectra raw data are also provided