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Understanding the sorption behavior of per- and poly-fluoroalkyl substances (PFAS) in soils are essential for assessing their mobility and risk in the environment. Heavy metals often coexist with PFAS depending on the source and history of contamination. In this study, we investigated the effect of heavy metal co-contaminants (Pb 2+ , Cu 2+ and Zn 2+ ) on the sorption of 13 anionic PFAS with different perfluorocarbon chain length (C3-C9) in two soils with different properties. Results revealed that Pb 2+ , Cu 2+ and Zn 2+ had little effect on the sorption of most short-chain compounds, while the presence of these heavy metals enhanced the sorption of long-chain PFAS in two soils. The distribution coefficients (K d ) of several long-chain PFAS linearly increased with increasing concentrations of heavy metal, especially in the presence of Pb 2+ (ΔK d /Δ [Pb 2+ ] > 3 for PFOS and PFNA vs <1 for PFPeS and PFHxS). While several mechanisms may have contributed to the enhancement of sorption of PFAS, the heavy metals most likely contributed through enhanced hydrophobic interactions of PFAS by neutralizing the negative charge of adsorption surfaces in soils and thus making it more favorable for their partitioning onto the solid phase. Moreover, the increase in the concentrations of heavy metals led to a decrease in the pH of the system and promoted sorption of long-chain compounds, especially in soil with lower organic carbon content. Overall, this study provides evidence that the presence of co-existing heavy metal cations in soils can significantly enhance the sorption of long-chain PFAS onto soil, thereby potentially limiting their mobility in the environment., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Wenwen Cai reports financial support was provided by China Scholarship Council., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Removal of per- and polyfluoroalkyl substances (PFASs) from water or their immobilization in soil using carbon-based sorbents is one of the cost-effective techniques. Considering the variety of carbon-based sorbents, identifying the key sorbent properties responsible for PFASs removal from solution or immobilization in the soil can assist in the selection of the best sorbents for management of contaminated sites. This study evaluated the performance of 28 carbon-based sorbents including granular and powdered activated carbon (GAC and PAC), mixed mode carbon mineral material, biochars, and graphene-based materials (GNBs). The sorbents were characterized for a range of physical and chemical properties. PFASs' sorption from an AFFF-spiked solution was examined via a batch experiment, while their ability to immobilize PFASs in soil was tested following mixing, incubation and extraction using the Australian Standard Leaching Procedure. Both soil and solution were treated with 1 % w/w sorbents. Comparing different carbon-based materials, PAC, mixed mode carbon mineral material and GAC were the most effective in sorbing PFASs in both solution and soil. Among the different physical characteristics measured, the sorption of long-chain and more hydrophobic PFASs in both soil and solution was best correlated with sorbent surface area measured using methylene blue, which highlights the importance of mesopores in PFASs sorption. Iodine number was found to be a better indicator of the sorption of short-chain and more hydrophilic PFASs from solution but was found to be poorly correlated with PFASs immobilization in soil for activated carbons. Sorbents with a net positive charge performed better than those with a net negative charge, or no net charge. This study showed that surface area measured by methylene blue and surface charge are the best indicators of sorbent performance with respect to sorption/reducing leaching of PFASs. These properties may be helpful in selecting sorbents for PFASs remediation of soils/waters., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Shervin kabiri reports financial support was provided by The University of Adelaide School of Agriculture Food & Wine. Shervin kabiri reports a relationship with The University of Adelaide School of Agriculture Food & Wine that includes: funding grants., (Copyright © 2023 Elsevier B.V. All rights reserved.)

This paper aims to describe the performance of a soil washing plant (SWP) for remediating a per- and poly-fluoroalkyl substances (PFASs)-contaminated soil with a high clay content (61%). The SWP used both physical and chemical processes; fractionation of the soil particles by size and partitioning of PFASs into the aqueous phase to remove PFASs from the soil. Contaminated water was treated in series with granulated activated carbon (GAC) and ion-exchange resin and reused within the SWP. Approximately 2200 t (dry weight) of PFAS-contaminated soil was treated in 25 batches of 90 t each, with a throughput of approximately 11 t soil/hr. Efficiency of the SWP was measured by observed decreases in total and leachable concentrations of PFASs in the soil. Average removal efficiencies (RE) were up to 97.1% for perfluorocarboxylic acids and 94.9% for perfluorosulfonic acids. REs varied among different PFASs depending on their chemistry (functional head group, carbon chain length) and were independent of the total PFAS concentrations in each soil batch. Mass balance analysis found approximately 90% of the PFAS mass in the soil was transferred to the wash solution and > 99.9% of the PFAS mass in the wash solution was transferred onto the GAC without any breakthrough., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Charles Grimison reports a relationship with Ventia Services that includes: employment., (Crown Copyright © 2022. Published by Elsevier B.V. All rights reserved.)

The effect of soluble cations on sorption in soils of a range of anionic PFAS is not well studied. We investigated the role of three common cations (Na + , Ca 2+ , and Mg 2+ ) at varying solution concentrations on the sorption coefficients (K d ) of 18 anionic PFAS in two contrasting soils. The effective charge of the soil suspension (Zeta potential) became less negative as the concentration of these cations increased in the soil solutions. Perfluorinated compounds showed greater sorption than polyfluorinated compounds, with sulfonates of comparable chain lengths showing higher sorption than the carboxylates. We observed that the K d values of several PFAS in the two soils were positively correlated with the concentration of cations in solution, especially in the presence of polyvalent cations (Ca 2+ and Mg 2+ ). The changes in sorption with cation concentration were more prominent for long-chain PFAS, with C > 10 PFAS being completely removed from solution at higher cation concentrations. The emerging PFAS (replacement compounds GenX and ADONA) showed negligible or little sorption (K d  < 0.6 L/kg). While several mechanisms contribute towards sorption of PFAS in the presence of cations, we conclude that the primary effect of cations is through screening of negative charges on head groups of PFAS and reorientation of molecules at the interface between organic matter surfaces and soil solution as well as charge neutralisation at soil solid surface. Screening of negative charges allows for greater hydrophobic interaction between hydrophobic tails of PFAS and soil surfaces resulting in greater sorption. Increasing cation concentrations in soil solutions could thus reduce mobility of PFAS through a soil profile., Competing Interests: Declaration of competing interest There are no conflicts of interest to declare., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

This study investigated the potential aging and plant bioaccumulation of three perfluoroalkyl acids (PFAAs), perfluorosulphonic acid (PFOS), perfluorooctanoic acid (PFOA) and perfluorohexanesulphonic acid (PFHxS) in 20 soils over a six-month period. Sorption coefficients (Log K d ) ranged from 0.13-1.28 for PFHxS, 0.17-1.06 for PFOA and 0.98-2.03 for PFOS, respectively, and bioaccumulation factors (Log BAFs) ranged from 0.29-1.24, 0.22-1.46 and 0.05-0.65 for PFHxS, PFOA and PFOS, respectively. Over the six-month period, K d values significantly increased for PFHxS and PFOA but the magnitude of the increase was very small and did not translate into differences in plant PFAA-concentrations between aged and freshly spiked treatments. The K d and BAF values were modelled by multiple linear regression (MLR) to soil physico-chemical properties and by partial least squares regression to soil spectra acquired by mid-infrared spectroscopy (DRIFT-PLSR). Modelling of each PFAA was influenced by different soil properties, including organic carbon, pH, CEC, exchangeable cations (Ca 2+ , Mg 2+ , Na + and K + ) and oxalate extractable Al. BAF values were not strongly correlated to any soil property but were inversely correlated to K d values. Our results indicate that limited aging occurred in these soils over the six-month period., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Urbanisation will be one of the 21st century's most transformative trends. By 2050, it will increase from 55% to 68%, more than doubling the urban population in South Asia and Sub-Saharan Africa. Urbanisation has multifarious (positive as well as negative) impacts on the wellbeing of humans and the environment. The 17 UN Sustainable Development Goals (SDGs) form the blueprint to achieve a sustainable future for all. Clean Water and Sanitation is a specific goal (SDG 6) within the suite of 17 interconnected goals. Here we provide an overview of some of the challenges that urbanisation poses in relation to SDG 6, especially in developing economies. Worldwide, several cities are on the verge of water crisis. Water distribution to informal settlements or slums in megacities (e.g. >50% population in the megacities of India) is essentially non-existent and limits access to adequate safe water supply. Besides due to poor sewer connectivity in the emerging economies, there is a heavy reliance on septic tanks, and other on-site sanitation (OSS) system and by 2030, 4.9 billion people are expected to rely on OSS. About 62-93% of the urban population in Vietnam, Sri Lanka, the Philippines and Indonesia rely on septic tanks, where septage treatment is rare. Globally, over 80% of wastewater is released to the environment without adequate treatment. About 11% of all irrigated croplands is irrigated with such untreated or poorly treated wastewater. In addition to acute and chronic health effects, this also results in significant pollution of often-limited surface and groundwater resources in Sub-Saharan Africa and Asia. Direct and indirect water reuse plays a key role in global water and food security. Here we offer several suggestions to mitigate water and food insecurity in emerging economies., Competing Interests: Declaration of competing interest The authors along with all co-authors are in agreement for the work being peer reviewed and possibly published and we have no undeclared competing financial interests or conflicts of interest., (Crown Copyright © 2020. Published by Elsevier B.V. All rights reserved.)

The sorption of three perfluoroalkyl substances (PFASs), namely perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA) and perfluorohexane sulfonic acid (PFHxS), was determined in 19 coastal sediments. There are currently limited data on the sorption behaviour of these chemicals in marine or estuarine sediments and the properties controlling their sorption have not been well established. The median average PFOS K d value (30.4 L/kg) was >8 times that for PFOA (3.3 L/kg) and PFHxS (2.8 L/kg). Highly significant (P < .001) linear relationships were found between values for sorption coefficients (K d ) for all three chemicals (PFOS, PFOA and PFHxS) to the estuarine sediments and organic carbon (OC) content with r 2 values ranging from 0.87 to 0.91. The nature of the constituents of OC was determined by nuclear magnetic resonance (NMR) for a subset (10) of the sediments to assess whether the strong relationship between sorption and OC was due solely to an increasing amount of OC or to particular OC fractions. The NMR analysis could not provide strong evidence for one OC fraction type explaining the variation in sorption of the three PFASs. Further investigation using partial least squares of the whole spectra also did not show any particular OC components could explain the K d variation. This data suggests that variation in sorption in these sediments was primarily due to the varying OC content and not its chemistry., Competing Interests: Declaration of competing interest All authors declare there is no conflict of interest., (Crown Copyright © 2020. Published by Elsevier B.V. All rights reserved.)

We studied sorption potential for a range of herbicides using eleven waste materials (mill muds) containing organic matter (47.6 to 65.1%) produced by sugar mills and applied as soil conditioners by farmers. Sorption/desorption behaviour of five herbicides commonly used in sugarcane production (imazapic, atrazine, hexazinone, diuron and metribuzin) was studied on these mill muds, as is and after adding these to three soils at different rates (5-25%, dry weight basis). All mill muds had significant sorption capacity, especially for diuron, atrazine and metribuzin which was 6 to 26 times higher than the soil with 3.5% organic carbon (OC). Generally, sorption of the five herbicides assessed in all mill muds followed the order diuron > atrazine = metribuzin > hexazinone = imazapic. Eight out of 11 mill muds had similar sorption capacity for any given herbicides. Amending soils with selected mill muds significantly enhanced their sorption efficiency, depending on the rate of application especially in soil with low OC. Generally, application of mill muds at 5% w/w or 40 tons/ha increased sorption of studied herbicides by 2 to 10 folds. Soil amendment with mill muds also reduced the rate and extent of desorption of herbicides- especially mobile herbicides like metribuzin. Nearly 79% release of metribuzin was observed after three desorption steps in amended soil (at 5% w/w), whereas in unamended soil, 100% of metribuzin was released during first desorption step. The study demonstrates that wastes produced by sugar mills may have recycling use in enhancing the retention of mobile herbicides in soils with low OC content., Competing Interests: Declaration of competing interest The authors have no competing financial interests or conflicts of interest., (Crown Copyright © 2020. Published by Elsevier B.V. All rights reserved.)

The aim of this study was to establish partitioning coefficients (K d ) of perfluorooctanoic acid (PFOA) in a wide range of soils and determine if those values can be predicted from soil properties using multiple linear regression (MLR) and from infrared spectra of soils using partial least squares regression (PLSR). For 100 different soils, the K d values of spiked radiolabelled 14 C-PFOA ranged from 0.6 to 14.8 L/kg and significantly decreased with soil depth (p < 0.05) due to soil properties that change with depth. The MLR modelling revealed that PFOA sorption was significantly (p < 0.05) influenced, in decreasing order, by organic carbon (OC) content, silt-plus-clay content and soil pH. Soils were partitioned into all soils and surface soils alone. The MLR models using OC, silt-plus-clay content and pH together explained most of the variation in sorption in all soils as well as surface soils alone (0-15 cm). However, correlations between soil properties and K d values in some soils could not be explained by the MLR model. Modelling of K d prediction in soils with PLSR and diffuse reflectance (mid) infrared Fourier transform spectroscopy (DRIFT) showed comparable success in explaining the predictions of K d values, including some of the outliers identified in the MLR model. The PLSR loading weights suggested that quartz, and possibly pyrophyllite minerals, were inversely correlated with the K d values. Given that MLR requires a-priori characterisation of a range of soil properties and PLSR-DRIFT is a method based on the direct relationship between spectra and soil components, mid-infrared spectroscopy may be a more economical and rapid technique to predict the solid-liquid partitioning of PFOA in soils., (Crown Copyright © 2019. Published by Elsevier B.V. All rights reserved.)

This study investigated the effect of surface charge on the sorption of perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA) and perfluorohexane sulfonic acid (PFHxS) onto 7 tropical soils as a function of pH. The net surface charge became less negative with decreasing pH (from 7.5 to 3.5) in all soils. The rate of change in net surface charge varied from -0.6 to -2.8 (cmol/kg)/pH unit. The effect on sorption behaviour of PFASs was variable among soils. For two soils, the average sorption increased 54- and 45-fold for PFOS, 33- and 9-fold for PFOA, and 39- and 400-fold for PFHxS, across the pH range 7.5 to 3.5. Sorption in another sandier soil showed negligible change with decreasing pH. Sorption in the other soils did not change significantly until the pH decreased to approximately 5.5. The soils with high contents of sesquioxides (Fe and Al oxides) showed the most marked increase in sorption with decreasing pH. This study demonstrated that in addition to hydrophobic interactions with OC and other processes, electrostatic interactions are also important in the sorption process for these chemicals in soils. In acidic, variably charged tropical soils there is the possibility that any PFOS, PFOA or PFHxS sorbed to the soils may become desorbed if management practices (e.g. liming) raised soil pH., (Copyright © 2019. Published by Elsevier B.V.)

Research over the last decade on emerging trace organic contaminants in aquatic systems has largely focused on sources such as treated wastewaters in high income countries, with relatively few studies relating to wastewater sources of these contaminants in low and middle income countries. We undertook a longitudinal survey of the Ahar River for a number of emerging organic contaminants (including pharmaceuticals, hormones, personal care products and industrial chemicals) which flows through the city of Udaipur, India. Udaipur is a city of approximately 450,000 people with no wastewater treatment occurring at the time of this survey. We found the concentrations of many of the contaminants within the river water were similar to those commonly reported in untreated wastewater in high income countries. For example, concentrations of pharmaceuticals, such as carbamazepine, antibiotics and non-steroidal anti-inflammatory drugs, ranged up to 1900 ng/L. Other organic contaminants, such as steroid estrogens (up to 124 ng/L), steroid androgens (up to 1560 ng/L), benzotriazoles (up to 11 μg/L), DEET (up to 390 ng/L), BPA (up to 300 ng/L) and caffeine (up to 37.5 μg/L), were all similar to previously reported concentrations in wastewaters in high income countries. An assessment of the population densities in the watersheds feeding into the river showed increasing population density of a watershed led to a corresponding downstream increase in the concentrations of the organic contaminants, with quantifiable concentrations still present up to 10 km downstream of the areas directly adjacent to the highest population densities. Overall, this study highlights how a relatively clean river can be contaminated by untreated wastewater released from an urban centre., (Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.)

Reuse of treated wastewater for irrigation of crops is growing in arid and semi-arid regions, whilst increasing amounts of biosolids are being applied to fields to improve agricultural outputs. Due to incomplete removal in the wastewater treatment processes, pharmaceuticals present in treated wastewater and biosolids can contaminate soil systems. Benzodiazepines are a widely used class of pharmaceuticals that are released following wastewater treatment. Benzodiazepines are represented by a class of compounds with a range of physicochemical properties and this study was therefore designed to evaluate the influence of soil properties on the sorption behaviour and subsequent uptake of seven benzodiazepines (chlordiazepoxide, clonazepam, diazepam, flurazepam, oxazepam, temazepam and triazolam) in two plant species. The sorption and desorption behaviour of benzodiazepines was strongly influenced by soil type and hydrophobicity of the chemical. The partitioning behaviour of these chemicals in soil was a key controller of the uptake and accumulation of benzodiazepines by radish (Raphanus sativus) and silverbeet (Beta vulgaris). Benzodiazepines such as oxazepam that were neutral, had low sorption coefficients (K d ) or had pH-adjusted log octanol-water partition coefficients (log D ow , pH6.3) values close to 2 had the greatest extent of uptake. Conversely, benzodiazepines such as flurazepam that had an ionised functional groups and greater K d values had comparatively limited accumulation in the selected plant species. Results also revealed active in-plant metabolism of benzodiazepines, potentially analogous to the known metabolic transformation pathway of benzodiazepines in humans. Along with this observed biological transformation of benzodiazepines in exposed plants, previously work has established the widespread presence of the plant signalling molecule γ-amino butyric acid (GABA), which is specifically modulated by benzodiazepines in humans. This highlights the need for further assessment of the potential for biological activity of benzodiazepines following their plant uptake., (Copyright © 2018. Published by Elsevier B.V.)

Widespread usage of per- and polyfluoroalkyl substances (PFASs) has caused major environmental contamination globally. The hydrophilic and hydrophobic properties of PFASs affect the sorption behaviour and suggest organic carbon may not be the only factor affecting sorption. We reviewed the quality of all data published in peer-reviewed literature on sorption of PFASs to critically evaluate the role organic carbon (OC) and other properties have in sorption of PFASs in soils or sediments. The largest data sets available were for perfluorooctanoic acid (PFOA, n = 147) and perfluorooctane sulfonic acid (PFOS, n = 178), and these analyses showed very weak correlations between sorption coefficient (K d ) and OC alone (R 2  = 0.05-0.07). When only laboratory-derived K d values of PFASs and OC were analysed, the R 2 values increased for PFOA (R 2  = 0.24, n = 42), PFOS (R 2  = 0.38, n = 69), perfluorononanoic acid (PFNA, R 2  = 0.77 n = 12), and perfluorodecanoic acid (PFDA, R 2  = 0.78, n = 13). However, the relationships were heavily skewed by one or two high OC values. Similarly there was no significant relationship between K d values and pH for PFOS (R 2  = 0.06) and PFOA (R 2  = 0.07), across a range of environmental pH values. Our analyses showed sorption behaviour of a range of PFASs could not be explained by a single soil or sediment property. Multiple regression models better explained the sorption behaviour of a number of PFASs. Regressions of OC and pH together explained a significant proportion of the variation in K d values for 9 out of 14 PFASs and 8 of these regressions had ≥10 data points. This review highlighted that at least OC, pH and clay content are properties having significant effect on sorption. There is a clear need for more data and studies with thorough characterisation of soils or sediments to better understand their role in PFASs sorption. Current assessments based on OC alone are likely to be erroneous., (Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.)

Ferrate(VI) (Fe(VI)) has been known to react with emerging organic contaminants containing electron-rich organic moieties, such as phenols, anilines, olefins, reduced sulfur and deprotonated amines. Oxidation of fluoroquinolone antibiotics, ciprofloxacin (CIP) and enrofloxacin (ENR), by Fe(VI) were investigated for their reaction products and toxicity changes as well as biodegradability of these products. Ten products were identified for both CIP and ENR reactions with Fe(VI) using a high-resolution accurate-mass Orbitrap mass analyzer. Structural changes to the CIP and ENR molecule included dealkylation, formation of alcohols and amides in piperazine ring and oxygen transfer to the double bond in quinolone structure. An enamine formation mechanism was tentatively proposed to facilitate the interpretation of CIP and ENR oxidation pathways. Toxicity evaluation using Microbial Assay for toxicity Risk Assessment (MARA) bioassay indicated that Fe(VI) oxidation products of CIP and ENR contributed negligible antibacterial potency and Fe(VI) oxidation treatment can remove the residual toxicity of CIP and ENR impacted source waters. The Fe(VI) oxidation treatment resulted in formation of relatively more biodegradable products (based on in silico assessment) than their corresponding parent compounds. The results showed that Fe(VI) has a good potential to degrade fluoroquinolone antibiotics and their antimicrobial potency in natural waters., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Two pesticide risk indicators, Pesticide Impact Rating Index (PIRI) and Environmental Potential Risk Indicator for Pesticides (EPRIP), were used to determine the likelihood of off-site transport to surface water of pesticides used in a cherry (Prunus avium cultivars) and an apple (Malus domestica cultivars) orchard. The predictions of off-site transport of some of the pesticides were verified against actual pesticide concentrations in surface water continuously monitored over two years. To our knowledge, only one other study in the published literature has attempted this. Of the chemicals monitored there was good agreement between the predictions and the field measurements from the apple orchard, but less so for the cherry orchard. In both risk indicators the attenuation factor based on the width of the buffer strip over-estimated the effectiveness of the buffer strip. There was good agreement between the EPRIP and PIRI risk assessment except for ethephon which EPRIP rated a higher risk than PIRI and dithianon which EPRIP rated a lower risk than PIRI. A strong correlation was found between the field observations and the EPRIP predicted environmental concentrations for the majority of cases. This study showed that even simple risk indicators (e.g. PIRI and EPRIP) can be good predictors for a first tier risk assessment of pesticide transport to neighbouring water bodies., (Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.)

Canola (Brassica napus L.) is the third largest field crop in Australia by area sown. Genetically modified (GM) and non-GM canola varieties released or being developed in Australia include Clearfield® (imidazolinone tolerant), TT (triazine tolerant), InVigor® (glufosinate-ammonium tolerant), Roundup Ready® - RR® (glyphosate tolerant) and Hyola® RT® (tolerant to both glyphosate and triazine). We used two risk assessment approaches - the Environmental Impact Quotient (EIQ) and the Pesticide Impact Rating Index (PIRI) - to compare the environmental risks associated with herbicides used in the canola varieties (GM and non-GM) that are currently grown or may be grown in the future. Risk assessments found that from an environmental impact viewpoint a number of herbicides used in the production of TT canola showed high relative risk in terms of mobility and ecotoxicity of herbicides. The EIQ field use rating values for atrazine and simazine in particular were high compared with those for glyphosate and trifluralin. Imazapic and imazapyr, which are only used in Clearfield® canola, had extremely low EIQ field use rating values, likely reflecting the very low application rates used for these chemicals (0.02 to 0.04kg/ha) compared with those used for atrazine and simazine (1.2 to 1.5kg/ha). The PIRI assessment showed that irrespective of the canola variety grown, trifluralin posed a high toxicity risk to fish (Rainbow trout, Oncorhynchus mykiss), algae and Daphnia sp. While the replacement of trifluralin with propyzamide had little effect on the mobility score, it greatly decreased the ecotoxicity score to fish, algae and Daphnia sp. due to the lower LC50 values for propyzamide compared with trifluralin. This study has shown that based on likelihood of off-site transport of herbicides in surface water and potential toxicity to non-target organisms, the GM canola varieties have no advantage over non-herbicide tolerant (non HT) or Clearfield® canola., (Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.)

Attenuation of pharmaceuticals due to natural sunlight is expected to be an important removal pathway in wastewater treatment plants using treatment lagoon systems. In this work, the photolysis of two antidepressants, amisulpride and desipramine, has been investigated in both ultrapure water and wastewater under simulated solar irradiation. Results showed that for amisulpride short irradiation times (t1/2 approximately 3h in pure water and 4h in wastewater) were adequate to degrade the parent compound while a longer exposure period was required for desipramine (t1/2 of approximately 36 h in pure water), although its degradation is enhanced almost three times by indirect photolysis in wastewaters. A significant number of transformation products (TPs) were identified for both pharmaceuticals by high-resolution mass spectrometry. In general, TPs formed are not persistent although acute toxicity tests for desipramine and its TPs showed an increase of the mixture toxicity after solar irradiation, suggesting that some TPs may be more toxic than the parent compound. In wastewaters collected from treatment lagoons, only amisulpride and one of its major TPs, TP 357, were detected. This indicates that long solar exposure times may be necessary for an effective elimination of these substances in lagoon systems or that photolysis may not be the main removal pathway for these particular compounds., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Owing of their wide-range of commercial applications, fullerene (C60) nanoparticles, are likely to reach environments through the application of treated sludge (biosolids) from wastewater treatment plants to soils. We examined the release behaviour of C60 from contaminated biosolids added to soils with varying physicochemical characteristics. Incubation studies were carried out in the dark for up to 24 weeks, by adding biosolids spiked (1.5mg/kg) with three forms of C60 (suspended in water, in humic acid, and precipitated/particulate) to six contrasting soils. Leaching of different biosolids+soil systems showed that only small fractions of C60 (<5% of applied amount) were released, depending on incubation time and soil properties (particularly dissolved organic carbon content). Release of C60 from unamended soils was greater (at least twice as much) than from biosolids-amended soils. The form of C60 used to spike the biosolids had no significant effect on the release of C60 from the different systems. Contact time of C60 in these systems only slightly increased the apparent release up to 8 weeks, followed by a decrease to 24 weeks. Mass balance analysis at the completion of the experiment revealed that 20-60% of the initial C60 applied could not be accounted for in these systems; the reasons for this are discussed., (Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.)

The anti-microbial agent triclosan (TCS), and its derivative methyl-triclosan (Me-TCS), are discharged with treated effluents from wastewater treatment plants to receiving environments. We investigated the bioconcentration of TCS and Me-TCS in mussels (Mytilus galloprovincialis) exposed to TCS (100 ng L(-1)) for 30 days in seawater aquaria (19±2°C) with fresh phytoplankton as a food source. Bioconcentration increased with time reaching a steady-state around 24-30 days. The bioconcentration factor (log BCF) for TCS were 2.81 L kg(-1) (dry weight) and 4.13 L kg(-1), when lipid normalised concentrations were used. Mussels were also deployed in cages at four marine locations receiving effluents from WWTPs. The mean (±SD) TCS and Me-TCS concentrations for mussels from these sites were 9.87 (±1.34) and 6.99 (±2.44) μg kg(-1). The study showed that mussels can be a useful tool for monitoring pollution of TCS and Me-TCS in marine and estuarine environments., (Copyright © 2013. Published by Elsevier Ltd.)

We investigated the biodegradation of three selected benzotriazoles (BTs), namely benzotriazole (BT), 5-methyl-benzotriazole (5-TTri) and 5-chloro-benzotriazole (CBT), in aquifer materials. Biodegradation experiments were conducted in microcosms with fresh groundwater and aquifer sediment materials under aerobic and anaerobic (nitrate, sulfate, and Fe (III) reducing) conditions. All three BTs were degraded by microorganisms in aquifer materials under aerobic and anaerobic conditions. Under aerobic conditions, BT and 5-TTri were found to be degraded fastest with their half-lives of 43 days and 31 days, respectively, among the redox conditions used. Under anaerobic conditions, CBT was found to be degraded better with its half-life of 21 days under nitrate reducing conditions than under aerobic conditions with its half-life of 47 days. The two BT derivatives 5-TTri and CBT could be biotransformed into BT via demethylation and dechlorination reactions, respectively., (Copyright © 2013 Elsevier B.V. All rights reserved.)

This study compared the degradation of indigenous bisphenol A (BPA) and triclosan (TCS) in a biosolids-amended soil, to the degradation of spiked labelled surrogates of the same compounds (BPA-d16 and TCS-(13)C12). The aim was to determine if spiking experiments accurately predict the degradation of compounds in biosolids-amended soils using two different types of biosolids, a centrifuge dried biosolids (CDB) and a lagoon dried biosolids (LDB). The rate of degradation of the compounds was examined and the results indicated that there were considerable differences between the indigenous and spiked compounds. These differences were more marked for BPA, for which the indigenous compound was detectable throughout the study, whereas the spiked compound decreased to below the detection limit prior to the study completion. The rate of degradation for the indigenous BPA was approximately 5-times slower than that of the spiked BPA-d16. The indigenous and spiked TCS were both detectable throughout the study, however, the shape of the degradation curves varied considerably, particularly in the CDB treatment. These findings show that spiking experiments may not be suitable to predict the degradation and persistence of organic compounds following land application of biosolids., (Copyright © 2013 Elsevier B.V. All rights reserved.)

This study investigated the sorption-desorption behaviour of four pesticides by a by-product from mineral sand mining, commonly referred to as neutralised used acid (NUA). In batch studies the average amount of pesticide removed after 6h was 69% for atrazine, 89% for diuron, 61% for 2,4-D and 83% for chlorpyrifos. The lower sorption of 2,4-D to NUA compared with the other pesticides studied is most likely to be due to the high pH of the solutions (7.8 to 8.8) which would have resulted in 2,4-D being predominantly in an anionic form. The presence of other pesticides only significantly decreased the amount of 2,4-D sorbed from 59% to 34% when present in a mixture. Little (2 to 17%) diuron, chlorpyrifos, atrazine or 2,4-D were found to desorb from the NUA. The presence of nitrate or phosphate had minimal effect on the amount of diuron or atrazine sorbed to the NUA. However, all phosphate and nitrate treatments significantly (P<0.05) decreased the amount of 2,4-D sorbed (<50%) compared with when 2,4-D was present alone (65%). This study has shown that NUA has potential to be used as a sorbent for pesticides., (Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.)

We studied the sorption-desorption behaviour of two herbicides (diuron and artrazine) in a soil rich in Fe and Al oxides (Ferrosol), either amended freshly with two different types of biochars or that contained biochars aged under field conditions. Standard batch sorption-desorption experiments were conducted on soil samples freshly amended with two biochars, (namely, poultry litter - PL and paper mill - PM sludge) as well on those collected from field 32 months after biochar application. Soils that were freshly amended with biochars @ 10 t ha(-1) showed a two (PM) to five (PL) fold increase in sorption of herbicides as compared with that in the unamended soil. For example, the fresh amendments with PL biochar at 10 t ha(-1) led to a highly significant (P<0.001) increase in the Freundlich sorption coefficient (K(f)) of atrazine; i.e. 20.71 (n=0.40) as compared with 4.02 (n=0.70) for the control soil. Sorption was reversible in the unamended soil but sorption-desorption hysteresis was prominent in the soil amended with fresh biochars. In contrast, the soil containing aged biochars (at 10 t ha(-1)) exhibited sorption-desorption properties that were statistically similar to that of the control soil, especially for atrazine. Ageing of biochars in the soil over a 32 months period reduced the sorption capacity by 47% (PM) to 68% (PL) for diuron. These findings may have implications for herbicide efficacy in biochar amended soils., (Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.)

We investigated how the sorption affinity of diuron (3'-(3,4-dichlorophenyl)-1,1-dimenthyl-urea), a moderately hydrophobic herbicide, is affected by soil properties, topography and management practices in an intensively managed orchard system. Soil-landscape analysis was carried out in an apple orchard which had a strong texture contrast soil and a landform with relief difference of 50 m. Diuron sorption (K(d)) affinity was successfully predicted (R(2)=0.79; p<0.001) using a mid-infrared - partial least squares model and calibrated against measured data using a conventional batch sorption technique. Soil and terrain properties explained 75% of the variance of diuron K(d) with TOC, pH(w), slope and WI as key variables. Mean diuron K(d) values were also significantly different (p<0.05) between alley and tree line and between the different management zones. Soil in the tree line generally had lower sorption capacity for diuron than soil in the alleys. Younger stands, which were found to have lower TOC than in the older stands, also had lower diuron K(d) values. In intensively managed orchards, sorption affinity of pesticides to soils was not only affected by soil properties and terrain attributes but also by management regime., (Copyright © 2012 Elsevier B.V. All rights reserved.)

A new method using gas chromatography-tandem mass spectrometry (GC-MS/MS) was developed for the determination of four benzotriazoles, i.e. benzotriazole (BT), 5-methylbenzotriazole (5-TTri), 5-chlorobenzotriazole (CBT), 5,6-dimethylbenzotriazole (XTri), and six UV filters, i.e. benzophenone-3 (BP-3), 3-(4-methylbenzylidene)camphor (4-MBC), octyl 4-methoxycinnamate (OMC), 2-(3-t-butyl-2-hydroxy-5-methylphenyl)-5-chloro benzotriazole (UV-326), 2-(2'-hydroxy-5'-octylphenyl)-benzotriazole (UV-329), and octocrylene (OC) in ground water, effluent and biosolid samples. Solid phase extraction (SPE) and pressurized liquid extraction (PLE) were applied as the preconcentration method for water samples (ground water and effluent) and biosolid samples, respectively. The optimized method allowed us to quantify all target compounds with the method detection limits ranging from 0.29 to 11.02 ng/L, 0.5 to 14.1 ng/L and 0.33 to 8.23 ng/g in tap water, effluent and biosolid samples, respectively. The recoveries of the target analytes in tap water, effluent and biosolid samples were 70-150%, 82-127% and 81-133%, respectively. The developed analytical method was applied in the determination of these target compounds in ground water, effluent and biosolid samples collected from Bolivar sewage treatment plants in South Australia. In effluent samples, the target compounds BT, 5-TTri, CBT, XTri and BP-3 tested were detected with the maximum concentration up to 2.2 μg/L for BT. In biosolid samples, eight out of ten compounds tested were found to be present at the concentrations ranging between 18.7 ng/g (5-TTri) and 250 ng/g (4-MBC)., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Personal care products (PCPs) and endocrine disrupting compounds (EDCs) are groups of organic contaminants that have been detected in biosolids around the world. There is a shortage of data on these types on compounds in Australian biosolids, making it difficult to gain an understanding of their potential risks in the environment following land application. In this study, 14 biosolids samples were collected from 13 Australian wastewater treatment plants (WWTPs) to determine concentrations of eight compounds that are PCPs and/or EDCs: 4-t-octylphenol (4tOP), 4-nonylphenol (4NP), triclosan (TCS), bisphenol A (BPA), estrone (E1), 17β-estradiol (E2), estriol (E3) and 17α-ethinylestradiol (EE2). Concentration data were evaluated to determine if there were any differences between samples that had undergone anaerobic or aerobic treatment. The concentration data were also compared to other Australian and international data. Only 4tOP, 4NP, TCS, and BPA were detected in all samples and E1 was detected in four of the 14 samples. Their concentrations ranged from 0.05 to 3.08 mg/kg, 0.35 to 513 mg/kg, <0.01 to 11.2 mg/kg, <0.01 to 1.47 mg/kg and <45 to 370 μg/kg, respectively. The samples that were obtained from WWTPs that used predominantly anaerobic treatment showed significantly higher concentrations of the compounds than those obtained from WWTPs that used aerobic treatment. Overall, 4NP, TCS and BPA concentrations in Australian biosolids were lower than global averages (by 42%, 12% and 62%, respectively) and 4tOP concentrations were higher (by 25%), however, of these differences only that for BPA was statistically significant. The European Union limit value for NP in biosolids is 50 mg/kg, which 4 of the 14 samples in this study exceeded., (Copyright © 2010 Elsevier B.V. All rights reserved.)

We report a survey on the occurrence of estrogens (estrone, E1; 17beta-estradiol, E2; 17alpha-ethynylestradiol, EE2) and xenoestrogens (bisphenol-A, BPA; 4-t-octylphenol, 4-t-OP; 4-nonylphenols, 4-NP; and nonylphenol mono- and di-ethoxylates, NPE1 and NPE2) in effluents from five wastewater treatment plants and their receiving waters in South East Queensland. The total xenoestrogen concentrations in effluent ranged between 2446 ng/L and 6579 ng/L, with 4-NP and NPE1-2 having much higher concentration levels than BPA and 4-t-OP. The estrogen levels in effluent varied from 9.12 to 32.22 ng/L for E1, from 1.37 ng/L to 6.35 ng/L for E2 and from 0.11 ng/L to 1.20 ng/L for EE2. No significant differences (p<0.05) in the concentrations of the selected estrogenic compounds were found for the effluents from the five sewage treatment plants. The estrogens and xenoestrogens were also found in the receiving waters at relatively lower concentration levels due to dilution of effluents in the rivers. Based on the chemical analysis data and relative potency of the compound from in vitro and in vivo bioassays from the literature, the calculated in vitro EEQ values (estrogen equivalents) in the receiving river waters downstream of the effluent discharge points ranged from 1.32 to 11.79 ng/L, while the in vivo EEQ values (vitellogenin response in rainbow trout) ranged from 2.48 to 21.18 ng/L. The three estrogens accounted for the majority of the EEQ in the water samples. This study indicates that the rivers of South East Queensland are at potential risk.