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The sorption behaviour of three perfluoroalkyl substances (PFASs), namely perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA) and perfluorohexane sulfonic acid (PFHxS), was determined on 28 tropical soils. Tropical soils are often highly weathered, richer in sesquioxides than temperate soils and may contain variable charge minerals. There are little data on sorption of PFASs in tropical soils. The highest K d values were found for PFOS with mean values ranging from 0 to 31.6 L/kg. The K d values for PFOA and PFHxS ranged from 0 to 4.9 L/kg and from 0 to 5.6 L/kg, respectively. While these values are in the range of literature sorption data, the average K d values for PFOS and PFOA from the literature were 3.7 times and 3.6 times higher, respectively, than those measured in this study. Stepwise regression analysis did explain some of the variance, but with different explanatory variables for the different PFASs. The main soil properties explaining sorption for PFOS and PFOA were oxalate-extractable Al and pH, and for PFHxS was pH., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Crown Copyright © 2019. Published by Elsevier Ltd. All rights reserved.)

Graphene-based nanomaterials (GNMs) have been touted as miracle materials due to their extraordinary properties that can benefit many industries, including in agriculture and for environmental remediation. While improvement in nutrient delivery and the ability to adsorb environmental contaminants have been demonstrated, what happens to GNMs in soil is a question that has not been addressed. The main aim of this study was to investigate their degradation in soil to have a better understanding of their environmental fate. Using radioisotope techniques, this study assessed the potential mineralisation and release of graphene oxide (GO), one of the most commonly used forms of graphene. Results revealed that the conversion of GO to carbon dioxide was negligible (<2%) in microbially-active soils. GO remaining in soil was also not readily released by water extractions. The lack of mineralisation and release is indicative of GO's high (bio)degradation stability which is likely due to its limited availability resulting from its rapid homo/hetero-aggregation. Over-all, the results provide new and important information on the environmental fate of graphene nanomaterials applied to soils., (Crown Copyright © 2019. Published by Elsevier Ltd. 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.)

Measurement and reporting of concentrations of contaminants of emerging concern such as per- and polyfluoroalkyl substances (PFASs), including perfluorooctanoic acid (PFOA), is an integral part of most investigations. Occurrence of sorption losses of PFAS analytes onto particular laboratory-ware (e.g. glass containers) has been suggested in the published literature but has not been investigated in detail. We examined sorption losses from aqueous PFOA solutions in contact with different commonly-used materials in filter units and centrifuge tubes (glass and plastics). Sorption of PFOA onto different filter membrane types ranged from 21-79% indicating that filtration can introduce a major source of error in PFOA analysis; pre-treatment of filter membranes with phosphate or methanol solutions did not improve PFOA recovery. Substantial adsorption of PFOA was also observed on tubes made from polypropylene (PP), polystyrene (PS), polycarbonate (PC), and glass where losses observed were between 32-45%, 27-35%, 16-31% and 14-24%, respectively. Contrary to suggestions in the literature, our results indicated that the greatest sorption losses for PFOA occurred on PP, whereas losses on glass tubes were much lower. Variations in ionic strength and pH did not greatly influence PFOA recovery. When PFOA concentrations were increased, the percent recovery of PFOA increased, indicating that binding sites on tube-walls were saturable. This study draws attention towards analytical bias that can occur due to sorption losses during routine procedures, and highlights the importance of testing the suitability of chosen laboratory-ware for specific PFAS analytes of interest prior to experimental use., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

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.)

Among a wide range of possible applications of nanotechnology in agriculture, there has been a particular interest in developing novel nanoagrochemicals. While some concerns have been expressed regarding altered risk profile of the new products, many foresee a great potential to support the necessary increase in global food production in a sustainable way. A critical evaluation of nanoagrochemicals against conventional analogues is essential to assess the associated benefits and risks. In this assessment, recent literature was critically analysed to determine the extent to which nanoagrochemicals differ from conventional products. Our analysis was based on 78 published papers and shows that median gain in efficacy relative to conventional products is about 20-30%. Environmental fate of agrochemicals can be altered by nanoformulations, but changes may not necessarily translate in a reduction of the environmental impact. Many studies lacked nano-specific quality assurance and adequate controls. Currently, there is no comprehensive study in the literature that evaluates efficacy and environmental impact of nanoagrochemicals under field conditions. This is a crucial knowledge gap and more work will thus be necessary for a sound evaluation of the benefits and new risks that nanoagrochemicals represent relative to existing products.

Plant protection products containing nanomaterials that alter the functionality or risk profile of active ingredients (nano-enabled pesticides) promise many benefits over conventional pesticide products. These benefits may include improved formulation characteristics, easier application, better targeting of pest species, increased efficacy, lower application rates, and enhanced environmental safety. After many years of research and development, nano-enabled pesticides are starting to make their way into the market. The introduction of this technology raises a number of issues for regulators, including how does the ecological risk assessment of nano-enabled pesticide products differ from that of conventional plant protection products? In this paper, a group drawn from regulatory agencies, academia, research, and the agrochemicals industry offers a perspective on relevant considerations pertaining to the problem formulation phase of the ecological risk assessment of nano-enabled pesticides.

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.)

Fullerenes (e.g. C 60 , C 70 , etc.) present in soil may undergo changes in its retention with aging. In this study, the partitioning behavior of ( 14 C)-C 60 aged up to 12 weeks was investigated in biosolids-amended soil. Spiked samples were subjected to sequential partitioning using water, methanol, and toluene followed by total combustion of solids; the distribution of 14 C across solvents and matrices were used to provide insights on C 60 behavior. In most samples, 14 C only partitioned in toluene with the remaining (non-extractable) activity detected in the solid phase. In all biosolids-amended soil samples, an increase in non-extractable 14 C were observed for those exposed to light (vs dark) with the greatest difference observed in biosolids + sand samples. Possible processes that contribute to the observed 14 C distribution, i.e. retention and potential transformation of C 60, were discussed. Over-all, results suggest that environmental exposure to C 60 and potentially transformed C 60 species, as a result of their release from soils, is likely to be low., (Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.)

Char as a carbon-rich material, can be produced under pyrolytic conditions, wildfires or prescribed burn offs for fire management. The objective of this study was to elucidate mechanistic interactions of copper (Cu 2+ ) and nickel (Ni 2+ ) with different chars produced by pyrolysis (green waste, GW; blue-Mallee, BM) and forest fires (fresh-burnt by prescribed fire, FC; aged char produced by wild fire, AC). The pyrolytic chars were more effective sorbents of Cu 2+ (∼11 times) and Ni 2+ (∼5 times) compared with the forest fire chars. Both cross-polarization (CPMAS-NMR) and Bloch decay (BDMAS-NMR) 13 C NMR spectroscopies showed that forest fire chars have higher woody components (aromatic functional groups) and lower polar groups (e.g. O-alkyl C) compared with the pyrolytic chars. The polarity index was greater in the pyrolytic chars (0.99-1.34) than in the fire-generated chars (0.98-1.15), while aromaticity was lower in the former than in the latter. Fourier transform infrared (FTIR) and Raman spectroscopies indicated the binding of carbonate and phosphate with both Cu 2+ and Ni 2+ in all chars, but with a greater extent in pyrolytic than forest fire-generated chars. These findings have demonstrated the key role of char's oxygen-containing functional groups in determining their sorption capacity for the Cu 2+ and Ni 2+ in contaminated lands., (Copyright © 2016 Elsevier Ltd. 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.)

Removal of a persistent antiepileptic drug carbamazepine (CBZ) in aqueous solutions was investigated by using solar photolysis combined with free available chlorine (FAC). The combination of chlorination with simulated or natural sunlight markedly enhanced removal of CBZ in 10 mM phosphate buffer solution (pH 7.0) and river water (pH 7.0) compared with sunlight or FAC alone. Further analysis indicated that the observed enhancements in CBZ removal can be attributed to the in situ hydroxyl radical (HO) and ozone (O3) production during FAC photolysis. During 70 min simulated sunlight photolysis combined with FAC treatment, HO reaction contributed to 35.8% removal of CBZ and O3 reaction contributed to 40.6% removal, while only 5.3% of CBZ was removed by HOCl reaction. The oxidation products of CBZ, epoxide CBZ, 10,11-dihydro-10,11-dihydroxy CBZ, 1-(2-benzaldehyde)-4-hydro-(1H,3H)-quinazoline-2-one (BQM), 1-(2-benzaldehyde)-(1H,3H)-quinazoline-2,4-dione (BQD) and 4-aldehyde-9-acridone, were mainly formed from the HO and O3 attack at the double bond on the central heterocyclic ring of CBZ. Formation of these oxidation products did not cause any increase or decrease in toxicity to microbial species tested through Microbial Assay for Toxicity Risk Assessment (MARA). The initial FAC concentration and pH had a major influence on the removal process of CBZ during FAC photolysis, while temperature had a minor effect only. The combination of chlorination with natural sunlight could provide an effective approach for removal of CBZ and other contaminants during water treatment., (Copyright © 2016 Elsevier Ltd. 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.)

The application of fixed bed high rate nitrifying trickling filters (NTFs) for the removal of track organic chemicals of concern (CoC) is less well known than their application to nutrient removal in water treatment. Particularly, the effect of exogenous organic carbon substrate (sucrose) loading on the performance of NTFs is not well understood. A laboratory-scale NTF system was operated in recirculation mode, with the objective of removing ammonia and CoC simultaneously. The efficiency of a high rate NTF for removal both of low concentration of ammonia (5 mg NH4-N L(-1)) and different concentrations of CoC in the presence of an exogenous organic carbon substrate (30 mg total organic carbon (TOC) L(-1)) was investigated. In the presence of exogenous organic carbon, the results demonstrated that the high rate NTF was able to successfully remove most of the CoCs investigated, with the removal ranging from 20.2% to 87.54%. High removal efficiencies were observed for acetaminophen (87.54%), bisphenol A (86.60%), trimethoprim (86.24%) and 17α-ethynylestradiol (80.60%). It was followed by the medium removal efficiency for N, N-diethyl-m-toluamide (61.31%) and atrazine (56.90%). In contrast, the removal of caffeine (28.43%) and benzotriazole (20.20%) was poorer in the presence of exogenous organic carbon. The removal efficiency for CoC was also compared with the results obtained in our previous study in the absence of exogenous organic carbon. The results showed that the addition of exogenous organic carbon was able to improve the removal of some of the CoC. Significant TOC percentage removals (45.68%-84.43%) and ammonia removal rate (mean value of 0.44 mg NH4-N L(-1) h(-1)) were also achieved in this study. The findings from this study provide valuable information for optimising the efficiency of high rate NTF for the removal of ammonia, CoC and TOC., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

This special issue presents a collection of papers covering the environmental fate, effects, and risk of pesticides in tropical environments, which is expected to facilitate improved management of pesticides. Environmental monitoring programs of surface and ground waters in the tropics, including areas of high ecological value, have detected several relatively polar pesticides at concentrations that are of ecological concern. Novel monitoring techniques have the capacity to reveal the spatial and temporal extent of such risks. To best manage these pesticides, their sorption, dissipation rates, leaching, and runoff potential need to be better understood. On these aspects, important insights have been provided by several studies within this issue. Improved understanding of the environmental fate, effects, and risks through studies presented in this special issue is crucial for minimizing the nontarget impacts of pesticides on biodiversity-rich tropical regions.

We evaluated the effects of the soil organic matter (SOM) composition, distribution between soil aggregates size, and their interactions with the mineral phase on herbicide sorption (alachlor, bentazon, and imazethapyr) in tropical and subtropical Oxisols under no-till systems (NT). Using soil physical fractionation approach, sorption experiments were performed on whole soils and their aggregates. SOM chemistry was assessed by CP/MAS (13)C NMR. The lower sorption observed in tropical soils was attributed to the greater blockage of SOM sorption sites than in subtropical soils. When these sites were exposed upon physical fractionation, sorption of the three herbicides in tropical soils increased, especially for imazethapyr. High amounts of poorly crystallized sesquioxides in these soils may have contributed to masking of sorption sites, indicating that organomineral interactions may lead to blockage of sorption sites on SOM in tropical soils.

Two experiments were conducted where three biochars, made from macadamia nutshell (MS), hardwood shaving (WS) and chicken litter (CL), were co-composted with chicken manure and sawdust, and also incubated with a chicken litter based commercial compost. Biochars were added at the rates of 5% and 10% in the co-composting and 10% and 20% in the incubation experiment. The rates of biochar had no consistent effect on the change in element contents of composted- or incubated-biochars. The biochar C demonstrated recalcitrance in both composting and incubation systems. Composting increased the CEC of biochars probably due to thermophilic oxidation. The increases in CEC of WS and CL were 6.5 and 2.2 times, respectively, for composting. Translocation of elements, between biochar and compost medium, occurred in both directions. In most cases, biochars gained elements under the influence of positive difference of concentrations (i.e., when compost medium had higher concentration of elements than biochar), while in some cases they lost elements despite a positive difference. Biochar lost some elements (WS: B; CL: B, Mg and S) under the influence of negative difference of concentrations. Some biochars showed strong affinity for B, C, N and S: the concentration of these elements gained by biochars surpassed the concentration in the respective composting medium. The material difference in the biochars did not have influence on N retention: all three netbag-biochars increased their N content. The cost of production of biochar-compost will be lower in co-composting than incubation, which involves two separate processes, i.e., composting and subsequent incubation., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

The detection of a range of active pharmaceutical ingredients (APIs) in the soil environment has led to a number of publications demonstrating uptake by crops, however very few studies have explored the potential for impacts on plant development as a result of API uptake. This study investigated the effect of carbamazepine and verapamil (0.005-10 mg/kg) on a range of plant responses in zucchini (Cucurbita pepo). Uptake increased in a dose-dependent manner, with maximum leaf concentrations of 821.9 and 2.2 mg/kg for carbamazepine and verapamil, respectively. Increased carbamazepine uptake by zucchini resulted in a decrease in above (<60%) and below (<30%) ground biomass compared to the controls (p < 0.05). At soil concentrations >4 mg/kg the mature leaves suffered from burnt edges and white spots as well as a reduction in photosynthetic pigments but no such effects were seen for verapamil. For both APIs, further investigations revealed significant differences in the concentrations of selected plant hormones (auxins, cytokinins, abscisic acid and jasmonates), and in the nutrient composition of the leaves in comparison to the controls (p < 0.05). This is some of the first research to demonstrate that the exposure of plants to APIs is likely to cause impacts on plant development with unknown implications.

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.)

The contamination of major continental river systems by endocrine-active chemicals (EACs) derived from the discharge of wastewater treatment plant (WWTP) effluents can affect human and ecosystem health. As part of a long-term effort to develop a native fish model organism for assessment of endocrine disruption in Australia's largest watershed, the Murray-Darling River Basin, the present study evaluated endocrine disruption in adult males of the native Australian Murray rainbowfish (Melanotaenia fluviatilis) exposed to effluent from an activated sludge WWTP and water from the Murray River during a 28-d, continuous-flow, on-site experiment. Analysis of the WWTP effluent and river water detected estrone and 17β-estradiol at concentrations up to approximately 25 ng L(-1) . Anti-estrogenicity of effluent samples was detected in vitro using yeast-based bioassays (yeast estrogen screen) throughout the experiment, but estrogenicity was limited to the first week of the experiment. Histological evaluation of the testes indicated significant suppression of spermatogenesis by WWTP effluent after 28 d of exposure. Plasma vitellogenin concentrations and expression of vitellogenin messenger RNA in liver were not significantly affected by exposure to WWTP effluent. The combination of low contaminant concentrations in the WWTP effluent, limited endocrine disrupting effects in the Murray rainbowfish, and high in-stream dilution factors (>99%) suggest minimal endocrine disruption impacts on native Australian fish in the Murray River downstream from the WWTP outfall., (© 2015 SETAC.)

Perfluoroalkyl substances (PFASs) have received great attention from the public and scientific community due to their potential adverse impacts on the ecosystem and human health. We investigated the occurrence and distribution of 16 PFASs from 2 classes of PFASs-perfluoroalkyl carboxylic acids and perfluoroalkane sulfonic acids-in the archived surface sediments of five major rivers (Yellow River, Hai River, Liao River, Zhujiang River, and Dongjiang River) in northern and southern China. The study was also performed during the wet and dry seasons. Perfluorooctanoic acid and perfluorooctane sulfonic acid were the most frequently detected (detection frequency = 100 and 63 %, respectively) in the sediments of the five rivers; the concentrations ranged from 0.08 to 0.99 ng/g dry weight (dw) and were lower than the limit of detection (

Sorption of non-ionic organic compounds to soil is usually expressed as the carbon-normalized partition coefficient (KOC), because it is assumed that the main factor that influences the amount sorbed is the organic carbon content of the soil. However, KOC can vary by a factor of at least ten across a range of soils. We investigated two potential causes of variation in diuron KOC - organic matter-mineral interactions and organic matter chemistry - for a diverse set of 34 soils from Sri Lanka, representing a wide range of soil types. Treatment with hydrofluoric acid (HF-treatment) was used to concentrate soil organic matter. HF-treatment increased KOC for the majority of soils (average factor 2.4). We attribute this increase to the blocking of organic matter sorption sites in the whole soils by minerals. There was no significant correlation between KOC for the whole soils and KOC for the HF-treated soils, indicating that the importance of organic matter-mineral interactions varied greatly amongst these soils. There was as much variation in KOC across the HF-treated soils as there was across the whole soils, indicating that the nature of soil organic matter is also an important contributor to KOC variability. Organic matter chemistry, determined by solid-state (13)C nuclear magnetic resonance (NMR) spectroscopy, was correlated with KOC for the HF-treated soils. In particular, KOC increased with the aromatic C content (R=0.64, p=1×10(-6)), and decreased with O-alkyl C (R=-0.32, p=0.03) and alkyl C (R=-0.41, p=0.004) content., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Active pharmaceutical ingredients (APIs) can enter the natural environment during manufacture, use and/or disposal, and consequently public concern about their potential adverse impacts in the environment is growing. Despite the bulk of the human population living in Asia and Africa (mostly in low- or middle-income countries), limited work relating to research, development and regulations on APIs in the environment have so far been conducted in these regions. Also, the API manufacturing sector is gradually shifting to countries with lower production costs. This paper focuses mainly on APIs for human consumption and highlights key differences between the low-, middle- and high-income countries, covering factors such as population and demographics, manufacture, prescriptions, treatment, disposal and reuse of waste and wastewater. The striking differences in populations (both human and animal), urbanization, sewer connectivity and other factors have revealed that the environmental compartments receiving the bulk of API residues differ markedly between low- and high-income countries. High sewer connectivity in developed countries allows capture and treatment of the waste stream (point-source). However, in many low- or middle-income countries, sewerage connectivity is generally low and in some areas waste is collected predominantly in septic systems. Consequently, the diffuse-source impact, such as on groundwater from leaking septic systems or on land due to disposal of raw sewage or septage, may be of greater concern. A screening level assessment of potential burdens of APIs in urban and rural environments of countries representing low- and middle-income as well as high-income has been made. Implications for ecological risks of APIs used by humans in lower income countries are discussed., (© 2014 The Author(s) Published by the Royal Society. All rights reserved.)

Batch experiments were conducted to evaluate the sorption-desorption behaviour of (14)C-labelled carboxylic acids (citric and oxalic) and amino acids (glutamic, alanine, phenylalanine and lysine) on pure minerals (kaolinite, illite, montmorillonite, ferrihydrite and goethite). The sorption experiments were complemented by ATR-FTIR spectroscopy to gain possible mechanistic insight into the organic acids-mineral interactions. In terms of charge, the organic solutes ranged from strongly negative (i.e., citric) to positively charged solutes (i.e., lysine); similarly the mineral phases also ranged from positively to negatively charged surfaces. In general, sorption of anionic carboxylic and glutamic acids was higher compared to the other compounds (except lysine). Cationic lysine showed a stronger affinity to permanently charged phyllosilicates than Fe oxides. The sorption of alanine and phenylalanine was consistently low for all minerals, with relatively higher sorption and lower desorption of phenylalanine than alanine. Overall, the role of carboxylic functional groups for the sorption and retention of these carboxylic and amino acids on Fe oxides (and kaolinite) and of amino group on 2:1 phyllosilicates was noticeable. Mineral properties (surface chemistry, specific surface area), chemistry of the organic compounds (pKa value, functional groups) and the equilibrium pH of the system together controlled the differences in sorption-desorption patterns. The results of this study aid to understand the effects of mineralogical and chemical factors that affect naturally occurring low molecular weight organic compounds sorption under field conditions., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Manufactured nanoparticles (NPs) present in consumer products could enter soils through re-use of biosolids. Among these NPs are those based on silver (Ag), which are found sulphidised (e.g. silver sulphide, Ag2S) in biosolids. Herein, our aim was to examine the release of retained Ag(0) and Ag2S NPs in soils and biosolids as facilitated by environmentally and agriculturally relevant ligands. Under natural soil conditions, exemplified by potassium nitrate and humic acid experiments, release of Ag retained in soil was limited. The highest total Ag release was facilitated by ligands that simulated root exudates (citrate) or fertilisers (thiosulphate). Released Ag was predominantly present in the colloidal phase (>3 kDa-< 0.45 μm); intact NPs only identified in Ag2S-NP extracts. For biosolids containing nanoparticulate-Ag-S, release was also enhanced by thiosulphate, though mostly as colloidal-Ag - not intact NPs. These results suggest that exposure to NPs as a result of its release from soils or biosolids will be low., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

We examined the impact of triclosan (TCS) and triclocarban (TCC) antimicrobial compounds on the biomineralisation of glucose and cadusafos pesticide in three Australian soils. Mineralisations of radiolabelled ((14)C) compounds were measured over a period of up to 77 d in sterile and non-sterile soils treated with different concentrations of TCS and TCC (0-450 mg kg(-1)). The rates of mineralisation of cadusafos were found to decrease with increasing concentration of TCS in all soils, but varied with soil type. Soils treated with TCS at the highest concentration (270 mg kg(-1)) reduced cadusafos mineralisation by up to 58%. However, glucose mineralisation was not significantly affected by the presence of TCS. While TCS, significantly reduced the mineralisation of cadusafos (by 17%; p<0.05) even at the lowest studied concentration (30 mg kg(-1)), no significant effect of TCC was observed on cadusafos or glucose mineralisation even at the highest concentration used (450 mg kg(-1))., (Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.)

Nanopesticides or nano plant protection products represent an emerging technological development that, in relation to pesticide use, could offer a range of benefits including increased efficacy, durability, and a reduction in the amounts of active ingredients that need to be used. A number of formulation types have been suggested including emulsions (e.g., nanoemulsions), nanocapsules (e.g., with polymers), and products containing pristine engineered nanoparticles, such as metals, metal oxides, and nanoclays. The increasing interest in the use of nanopesticides raises questions as to how to assess the environmental risk of these materials for regulatory purposes. Here, the current approaches for environmental risk assessment of pesticides are reviewed and the question of whether these approaches are fit for purpose for use on nanopesticides is addressed. Potential adaptations to existing environmental risk assessment tests and procedures for use with nanopesticides are discussed, addressing aspects such as analysis and characterization, environmental fate and exposure assessment, uptake by biota, ecotoxicity, and risk assessment of nanopesticides in aquatic and terrestrial ecosystems. Throughout, the main focus is on assessing whether the presence of the nanoformulation introduces potential differences relative to the conventional active ingredients. The proposed changes in the test methodology, research priorities, and recommendations would facilitate the development of regulatory approaches and a regulatory framework for nanopesticides.

Pharmaceuticals have been detected in the soil environment where there is the potential for uptake into crops. This study explored the fate and uptake of pharmaceuticals (carbamazepine, diclofenac, fluoxetine, propranolol, sulfamethazine) and a personal care product (triclosan) in soil-plant systems using radish (Raphanus sativus) and ryegrass (Lolium perenne). Five of the six chemicals were detected in plant tissue. Carbamazepine was taken up to the greatest extent in both the radish (52 μg/g) and ryegrass (33 μg/g), whereas sulfamethazine uptake was below the limit of quantitation (LOQ) (<0.01 μg/g). In the soil, concentrations of diclofenac and sulfamethazine dropped below the LOQ after 7 days. However, all pharmaceuticals were still detectable in the pore water at the end of the experiment. The results demonstrate the ability of plant species to accumulate pharmaceuticals from soils with uptake apparently specific to both plant species and chemical. Results can be partly explained by the hydrophobicity and extent of ionization of each chemical in the soil.

Indaziflam is a relatively new herbicide for which sorption-desorption information is lacking, and nothing is available on its metabolites. Information is needed on the multiple soil and pesticide characteristics known to influence these processes. For four soils, the order of sorption was indaziflam (N-[1R,2S)-2,3-dihydro-2,6-dimethyl-1H-inden-1-yl]-6-[(1R)-1-fluoroethyl]-1,3,5-triazine-2,4-diamine) (sandy clay loam: Kf = 5.9, 1/nf = 0.7, Kfoc = 447; sandy loam: Kf = 3.9, 1/nf = 0.9, Kfoc = 276) > triazine indanone metabolite (N-[(1R,2S)-2,3-dihydro-2,6-dimethyl-3-oxo-1H-inden-1-yl]-6-[(1R)-1-fluoroethyl]-1,3,5-triazine-2,4-diamine) (sandy clay loam: Kf = 2.1, 1/nf = 0.8, Kfoc = 177; sandy loam: Kf = 1.7, 1/nf = 0.9, Kfoc = 118) > fluoroethyldiaminotriazine metabolite (6-[(1R-1-Fluoroethyl]-1,3,5-triazine-2,4-diamine) (sandy clay loam: Kf = 0.3, 1/nf = 0.9, Kfoc = 28; sandy loam: Kf = 0.3, 1/nf = 0.9, Kfoc = 22) = indaziflam carboxylic acid metabolite (2S,3R)-3-[[4-amino-6-[(1R)-1-fluoroethyl]-1,3,5-triazin-2-yl]amino]-2,3-dihydro-2-methyl-1H-indene-5-carboxylic acid) (sandy clay loam: Kf = 0.3, 1/nf = 0.9, Kfoc = 22; sandy loam: Kf = 0.5, 1/nf = 0.8, Kfoc = 32). The metabolites being more polar than the parent compound showed lower sorption. Desorption was hysteretic for indaziflam and triazine indanone metabolite, but not for the other two metabolites. Unsaturated transient flow Kd's were lower than batch Kd's for indaziflam, but similar for fluoroethyldiaminotriazine metabolite. Batch Kd's would overpredict potential offsite transport if desorption hysteresis is not taken into account.

Estrogenic compounds may enter the environment when biosolids are applied to land. In the present study, soil samples were collected over 4 mo from a field trial following addition of biosolids. The recombinant yeast estrogen screen bioassay identified estrogenic activity in the soil at all sampling times to concentrations up to 2.3 µg 17β-estradiol equivalency/kg. The present results indicate the potential for estrogenic compounds to persist in soil following biosolids application.

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 the occurrence and removal of four benzotriazoles (BTs) (benzotriazole: BT; 5-methyl-benzotriazole: 5-TTri; 5-chloro-benzotriazole: CBT; 5,6-dimethyl-benzotriazole: XTri) and six UV filters (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; octocrylene: OC) in a full scale municipal wastewater treatment in South Australia. BT, 5-TTri and BP-3 were found as the dominant compounds detected in the wastewater samples with average concentrations up to 5706 ± 928 ng/L, 6758 ± 1438 ng/L and 2086 ± 1027 ng/L in influent, and up to 2439 ± 233 ng/L, 610 ± 237 ng/L and 153 ± 121 ng/L in effluent, respectively. In the biosolid, 4-MBC and OC were found with the highest concentrations of 962 ± 135 ng/g and 465 ± 65 ng/g, respectively. Sorption onto sludge played a dominant role in the removal for UV filters, especially for 4-MBC, UV-326 and OC, which accounted for 54%-92% of influent loads, while biological degradation played a significant role for the other compounds., (Copyright © 2011 Elsevier Ltd. 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.)

The persistence of contaminants entering the environment through land application of biosolids needs to be understood to assess the potential risks associated. This study used two biosolids treatments to examine the dissipation of four organic compounds: 4-nonylphenol, 4-t-octylphenol, bisphenol A and triclosan, under field conditions in South Australia. The pattern of dissipation was assessed to determine if a first-order or a biphasic model better described the data. The field dissipation data was compared to previously obtained laboratory degradation data. The concentrations of 4-nonylphenol, 4-t-octylphenol and bisphenol A decreased during the field study, whereas the concentration of triclosan showed no marked decrease. The time taken for 50% of the initial concentration of the compounds in the two biosolids to dissipate (DT50), based on a first-order model, was 257 and 248 d for 4-nonylphenol, 231 and 75 d for 4-t-octylphenol and 289 and 43 d for bisphenol A. These field DT50 values were 10- to 20-times longer for 4-nonylphenol and 4-t-octylphenol and 2.5-times longer for bisphenol A than DT50 values determined in the laboratory. A DT50 value could not be determined for triclosan as this compound showed no marked decrease in concentration. The biphasic model provided a significantly improved fit to the 4-t-octylphenol data in both biosolids treatments, however, for 4-nonylphenol and bisphenol A it only improved the fit for one treatment. This study shows that the use of laboratory experiments to predict field persistence of compounds in biosolids amended soils may greatly overestimate degradation rates and inaccurately predict patterns of dissipation., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Biodegradation of the ultraviolet (UV) filter benzophenone-3 (BP-3) was investigated in the laboratory to understand its behavior and fate under oxic and anoxic (nitrate, sulfate, and Fe [III]-reducing) conditions. Biodegradation experiments were conducted in microcosms with 10% of activated sludge and digested sludge under oxic and anoxic conditions, respectively. Benzophenone-3 was well degraded by microorganisms under each redox condition. Under the redox conditions studied, the biodegradation half-life for BP-3 had the following order: oxic (10.7 d) > nitrate-reducing (8.7 d) > Fe (III)-reducing (5.1 d) > sulfate-reducing (4.3 d) ≥ anoxic unamended (4.2 d). The results suggest that anaerobic biodegradation is a more favorable attenuation mechanism for BP-3. Biodegradation of BP-3 produced two products, 4-cresol and 2,4-dihydroxybenzophenone, under oxic and anoxic conditions. Biotransformation of BP-3 to 2,4-dihydroxybenzophenone by way of demethylation of the methoxy substituent (O-demethylation) occurred in cultures under each redox condition. The further biotransformation of 2,4-dihydroxybenzophenone to 4-cresol was inhibited under oxic, nitrate-reducing, and sulfate-reducing conditions., (Copyright © 2011 SETAC.)

We examined the biodegradability of three benzotriazoles (benzotriazole: BT, 5-methylbenzotriazole: 5-TTri and 5-chlorobenzotriazole: CBT) under aerobic and anaerobic (nitrate, sulfate, and Fe (III) reducing) conditions. All three benzotriazoles were degraded by microorganisms under aerobic and anaerobic conditions. Both the biodegradation efficiency and biodegradation products were dependent on the predominant terminal electron-accepting condition. Among the redox conditions studied, the shortest biodegradation half lives for BT and 5-TTri were 114 days and 14 days, respectively, under aerobic condition. The shortest half-life for CBT was 26 days under Fe (III) reducing condition. The longest biodegradation half lives for BT and CBT were 315 days and 96 days, respectively, under sulfate reducing condition, while that of 5-TTri was 128 days under nitrate reducing condition. These results suggest that aerobic biodegradation is the dominant natural attenuation mechanism for BT and 5-TTri, while the most favorable process for CBT was anaerobic biodegradation. This study demonstrated that different predominant terminal electron-acceptors present in natural environment play a key role on the biodegradation of BT, 5-TTri and CBT, leading to specific biodegradability. This could have significant implications on in-situ biodegradation of the selected benzotriazoles in aerobic and anaerobic waters, soils and sediments., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Land application of biosolids is common practice in many countries, however, there are some potential risks associated with the presence of contaminants within the biosolids. This laboratory study examined the degradation of four commonly found organic compounds, 4-nonylphenol, 4-t-octylphenol, bisphenol A, and triclosan, in soil following the addition of two biosolids over 32 weeks. The pattern of degradation was assessed to determine if it followed a standard first-order decay model or if a biphasic model with a degrading and a recalcitrant fraction better described the data. The time taken for the initial concentrations to decrease by 50% (DT50), based on a first-order model, was 12-25 d for 4-nonylphenol, 10-14 d for 4-t-octylphenol, 18-102 d for bisphenol A, and 73-301 d for triclosan. For 4-nonylphenol, bisphenol A and triclosan, the biphasic model fitted the degradation data better than the first-order model, indicating the presence of a degrading fraction and a non-degrading recalcitrant fraction. The recalcitrant fraction for these three compounds at the completion of the 32 week experiment was 17-21%, 24-42%, and 30-51% of the initial concentrations, respectively. For 4-t-octylphenol, the first-order model was sufficient in explaining the degradation data, indicating that no recalcitrant fraction was present. This study showed that biphasic degradation occurred for some organic compounds in biosolids amended soil and that the use of standard first-order degradation models may underestimate the persistence of some organic compounds following land application of biosolids., (Crown Copyright © 2011. Published by Elsevier Ltd. 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.)

We studied the sorption behaviour of fullerene nano-C(60) particles (nC(60)) in soil from binary solvent mixtures of ethanol-water in order to critically evaluate the previous reports in the literature that the partitioning mechanism explains the soil sorption of fullerene C(60) as hydrophobic molecules. The sorption of nC(60) particles was studied in a range of solvent mixtures by changing volume fractions of ethanol from 20 to 100 percent. Sorption and particle characteristics were found to be very different in ethanol : water mixtures above and below 60% ethanol. In the range of 20-60% ethanol, sorption increased from 1.2 to 14.6 L kg(-1) accompanied by a change in zeta (ζ) potential from -32.4 to -7.2 mV. This observation can be attributed to hydrophilic interactions that negatively charged nC(60) particles undergo with soil colloids and water molecules. From 60% to 100% ethanol volume fractions, hydrophobic interactions of weakly charged nanoparticles may control the overall extent of soil sorption. The findings of this study indicate the importance of hydrophilic forces in controlling the sorption behaviour of nC(60) particles which are stabilized in water dominated solvent mixtures. The validity of the partitioning mechanism and K(OC) modelling approach in describing and estimating the sorption of nC(60) particles in soil (previously suggested in the literature) are, therefore, questioned.

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.)