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Mitigation measures are needed to prevent large loads of phosphate originating in agriculture from reaching surface waters. Iron-coated sand (ICS) is a residual product from drinking water production. It has a high phosphate adsorption capacity and can be placed around tile drains, taking no extra space, which increases the farmers' acceptance. The main concern regarding the use of ICS filters below groundwater level is that limited oxygen supply and high organic matter concentrations may lead to the reduction and dissolution of iron (hydr)oxides present and the release of previously adsorbed phosphate. This study aimed to investigate phosphate adsorption on ICS at the onset of iron reduction. First, we investigated whether simultaneous metal reduction and phosphate adsorption were relevant at two field sites in the Netherlands that use ICS filters around tile drains. Second, the onset of microbially mediated reduction of ICS in drainage water was mimicked in complementary laboratory microcosm experiments by varying the intensity of reduction through controlling the oxygen availability and the concentration of degradable organic matter. After 3 yr, ICS filters in the field removed phosphorus under low redox conditions. Over 45 d, the microbial reduction of manganese and iron oxides did not lead to phosphate release, confirming field observations. Electron microscopy and X-ray absorption spectroscopy did not evince systematic structural or compositional changes; only under strongly reducing conditions did iron sulfides form in small percentages in the outer layer of the iron coating. Our results suggest that detrimental effects only become relevant after long periods of operation.

Water quality can have serious impacts on human health. One crucial issue of water pollution seriously affects our safety due to the continually emerging of discovered anthropogenic pollutants. The water treatment technologies are persistent improvement to adapt such new contaminants, which accelerates the evolution of materials science to explore solving the problems. Metal-organic Frameworks (MOFs) as the significant porous and multi-dimensional networks has been concerned for toxic pollutant elimination, especially probed the applications of outstanding layered 2D skeletons MOFs-based materials. The emphases of this review highlight the 2D MOFs-based materials used in water remediation and treatment strategies including adsorption and catalysis methods. Further, the prospects and challenges of 2D MOFs-based materials for water treatments applications would be surveyed meticulously for the future research and development.

Water pollution and crisis of freshwater is one of the most alarming concern globally, which threatens the development and survival of living beings. Recycling of contaminated water has been the prime demand of 21st century as the area of contamination in natural waterbodies increasing rapidly worldwide. Detoxification and purification of wastewater via adsorptive removal technology has been proven to be more efficient because of it's simplicity, lesser complexity and cost-effectiveness. As the most rapid-growing division of coordination chemistry, porous coordination polymers (PCPs) or metal-organic frameworks (MOFs) with the liberty of crafting tailorable porous architecture and presence of numerous functional sites have become quintessential for recognition and sequestration of water pollutants. This personal account intends to highlight our recent contributions in the field of sensing and sequestration of toxic aquatic inorganic pollutants by functionalized water stable MOFs.

Anthropogenic effects on the aquatic environment are ever present and ever increasing and while a plethora of aquatic contaminants are known to affect fishes, one ubiquitous and increasingly prevalent world‐wide urban runoff pollutant is frequently disregarded, and that is pet waste. While dog waste has been identified as a significant factor contributing to bacteria and nutrient loading within receiving waters and the associated water quality changes are known to affect fishes, the impact of uncollected dog faeces on urban fish populations has never been directly investigated. In this study we exposed creek chub (Semotilus atromaculatus), a widespread tolerant stream minnow, to various realistic concentrations of dog waste as simulated urban park runoff testing both fresh and dried dog faeces in both stagnant and aerated water for 96 h to investigate the impact on fish survival and behaviour. Creek chub percentage mortality increased significantly relative to controls and across an exposure gradient and was likely caused by anoxic conditions. Survivors were initially smaller while those that died were initially larger and presented with abnormal abdominal subdermal lesions post‐exposure. Additional indicators of physiological stress included significantly increased rates of aquatic surface respiration and changes in flume test derived swimming motivation metrics with increased exposure concentrations. Both mortality and behavioural responses were alleviated by aeration. Furthermore, trials with fresh and dried faeces differed only in time‐to‐death and swimming metrics where results from dried trials were similar to those from aerated experiments. Results demonstrated the impact that the global dog waste management problem can have on aquatic communities with effects on creek chub likely to be more severe for less pollution‐tolerant species and also likely to be exacerbated under future scenarios that consider climate change and increased urbanization.

Currently, our environment is contaminated with various toxic substances. Removal of such hazardous materials from water, air and fuel is important for sustainability. In this minireview, adsorptive removal of organic substances, by using metal-organic frameworks (MOFs), for our safe environment will be discussed. For example, removal of (i) pharmaceuticals/personal care products, pesticides, and dyes from water; (ii) S- or N-containing compounds from liquid fuel; and (iii) volatile organic compounds from air will be summarized. Moreover, plausible mechanisms to explain the observation will also be discussed. Finally, prospects in the field will be suggested for further research and development.

This section presents a review of the scientific literature published in 2019 on topics relating to distributed treatment systems. This review is divided into the following sections: constituent removal, treatment technologies, planning and treatment management, and other topics. PRACTITIONER POINTS: Highlights changes and innovation in removal techniques and technologies in water treatment. Reviews management systems of distributed treatment systems. Discusses point-of-use treatment systems.

The wastewater from the dumping site usually contains high pollutant levels. Biological process and physico-chemical treatments are among several technologies for wastewater treatment. Using microorganisms in the treatment of landfill leachate is an emerging research issue. Furthermore, bioremediation is a feasible approach for pollutants removal from landfill leachate which would provide an efficient way to resolve the issue of landfill leachate. In this study, the performance of yeast and bacteria isolated from kefir grains was assessed for landfill leachate treatment. Kefir grains microbial composition was evaluated by molecular approaches (Rep-PCR and 16S rRNA gene sequencing). The obtained outcomes denoted that high concentrations of lactic acid bacteria and yeast populations (over 107 CFU/ml) were found in the kefir grains and were essentially composed of Lactococcus lactis, Lactobaccillus kefirien, bacillus sp., L. lactis, and Kluyveromyces marxianus. The co-culture with 1% of inoculum size was demonstrated as the most efficient in the degradation of different contaminants. The overall abatement rate of chemical oxygen demand (COD), ammonium nitrogen ( NH 4 + - N ), and salinity were 75.8%, 85.9%, and 75.13%, respectively. The bioremediation process resulted in up of 75% removal efficiency of Ni and Cd, and a 73.45%, 68.53%, and a 58.17% removal rates of Cu, Pb, and Fe, respectively. The research findings indicate the performance of L. lactis and K. marxianus co-culture isolated from kefir grains for the bioremediation of LFL. PRACTITIONER POINTS: Isolation and identification of microorganisms from kefir grains was carried out. Biological treatment of LFL using monoculture of (Lactoccocus lactis; Kluyveromyces marxianus) and co-culture (5% of L. lactis and 5% K. marxianus) has been performed. Biological treatment using co-culture strain is an effective approach to remove organic matter, NH 4 + - N and heavy metals.

Fish erythrocytes are very sensitive to environmental pollution because they exhibit pathological alterations before appearance of other external symptoms, may be used as reliable toxicity bioindicators. Microscopic analysis can be a useful tool in early detection of alterations in erythrocyte morphology due to different environmental stressors, and in predicting organism's possible response ways. This study aims to evaluate the toxicity of a polluted freshwater lake on the erythrocytes of crucian carp fish, Carassius carassius, using digital light microscopy (DLM). Scanning DLM micrographs revealed the presence of nuclear and cytoplasmic abnormalities like micronucleus, nuclear buds, lobed nucleus, deformed nucleus, vacuolated cytoplasm, and echinocyte in the erythrocytes of crucian carp fish from a polluted lake. The obtained results substantiate that computation of erythrocyte morphological damages as biomarkers of exposure, through digital light microscopy software, can be effectively used as a toxicological tool.

Nitrogen runoff from pastures fertilized with animal manure, such as poultry litter, can result in accelerated eutrophication. The objective of this study was to evaluate the long-term effects of grazing management and buffer strips on N runoff from pastures fertilized with poultry litter. A 12-yr study was conducted on 15 small watersheds in Booneville, AR, using five management practices: continuous grazing, haying, rotational grazing, rotational grazing with an unfertilized buffer strip, and rotational grazing with a fenced unfertilized riparian buffer. Poultry litter was applied annually at a rate of 5.6 Mg ha. Concentrations and loads of total N, NO-N, NH-N, organic N, and total organic C in runoff varied intra- and interannually and coincided with precipitation trends. Overall, the greatest component of total N in runoff was organic N. Rotational grazing resulted in the highest concentrations and loads of all forms of N in runoff compared with other treatments, including the continuously grazed paddocks, which were grazed almost twice as much. Total organic C concentrations and loads in runoff were also higher from rotationally grazed watersheds than other treatments. Rotational grazing is considered a best management practice that typically reduces soil erosion; hence, the mechanism by which it caused higher N and C runoff is unclear. Nitrogen runoff losses from rotationally grazed pastures were reduced by 44% with unfertilized buffer strips, by 54% with fenced unfertilized riparian buffers, and by 52% by converting pastures to hayfields.

A column study was conducted to test the ability of bioretention soil mixtures (BSMs) to remove nutrients, metals, and polyaromatic hydrocarbons (PAHs) from stormwater collected from an urban highway. Infiltration rate, plant growth response, and turbidity of the effluent were also measured. The BSMs were made from a range of types and rates of composts and additional materials such as water treatment residuals, sawdust, and oyster shells. Sand was used as a control. Total N and P in stormwater measured 1.8 ± 1 and 0.08 ± 0.03 mg L. All treatments were a source of these nutrients. Metal concentrations in the stormwater were low, with mean Cu and Zn concentrations of 39.8 ± 19.1 and 173 ± 113 μg L, and Cd and Pb close to detection limits. All treatments absorbed Cu and Zn from stormwater with varying levels of removal efficiency. The three treatments tested removed 84 to 100% of the PAHs from the stormwater. In general, contaminant removal (N, P, and Zn) efficiency was not related to infiltration rate, with a slight decrease in Cu removal efficiency observed with increased infiltration rate ( = 0.32). These results indicate that the BSMs tested were a source of nutrients but were generally effective at removing metals and PAHs from stormwater.

Vegetated buffer strips (VBS) between agricultural areas and surface waters are important retention areas for eroded particulate P through which they may obtain critically high degrees of P saturation imposing high risk of soluble P leaching. We tested topsoil removal and three harvesting frequencies (once, twice, or four times per year) of natural buffer vegetation to reduce P leaching with the aim to offset erosional P accumulation and high degrees of P saturation. We used a simple numerical time-step model to estimate changes in VBS soil P levels with and without harvest. Harvesting offset erosional deposition as it resulted in an annual ammonium oxalate-extractable P reduction of 0.3 to 2.8% (25-cm topsoil content) in soils of the VBS and thus, with time, reduced potential P leaching below a baseline of 50 mg L-1. Topsoil removal only marginally reduced potential leaching at two sites and not anywhere near this baseline. The harvest frequency only marginally affected the annual P removal, making single annual harvests the most economical. We estimate 50 to 300 yr to reach the P leaching baseline, due to substantial amounts of P accumulated in the soils. Even in high-erosion-risk situations in our study, harvesting reduced soil P content and the P leaching risk. We suggest harvesting as a practical and efficient management to combat P leaching from agricultural VBS, not just for short-term reductions of dissolved P, but also for reductions of the total soil P pool and for possible multiple benefits for VBS.

Graphene is a 2-dimensional nanomaterial with unique mechanical, thermal, electrical, and optical properties. With increasing applications of graphene-family nanomaterials (GFNs) in electronics, biomedicine, and surface coatings, concern for their impacts on aquatic ecosystems is rising. Current information on the toxicity of GFNs, including graphene oxide, is scarce. Filter-feeding bivalves, such as eastern oysters, are good models for nanomaterial exposure studies. We present results from a 72-h static renewal oyster study using 1 and 10 mg/L graphene oxide, which, to our knowledge, is the first report on in vivo effects of graphene oxide exposures in marine bivalves. Water samples were analyzed for graphene oxide concentration and size assessments. Gill and digestive gland tissues were evaluated for lipid peroxidation and glutathione-S-transferase (GST) activity. In addition, gill sections were fixed for histopathological analyses. Elevated lipid peroxidation was noted in oysters exposed to 10 mg/L graphene oxide. No significant changes in GST activity were observed, but reduced total protein levels were found in digestive gland tissues of exposed oysters at both concentrations. Loss of mucous cells, hemocytic infiltration, and vacuolation were observed in gills of exposed oysters. The results indicate that short-term graphene oxide exposures can induce oxidative stress and epithelial inflammation and adversely affect overall oyster health. Further investigations regarding the fate and sublethal effects of graphene oxide are critical to understanding the risks associated with a rapidly growing graphene consumer market. Environ Toxicol Chem 2019;38:820-830. Published 2019 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

A simple model is developed to describe the instantaneous (rv ) and cumulative (Rv ) recovery of viruses from water during sample concentration by tangential flow filtration in the regime of constant water recovery, r. A figure of merit, M = rv r, is proposed as an aggregate performance metric that captures both the efficiency of virus recovery and the speed of sample concentration. We derive an expression for virus concentration in the sample as a function of filtration time with the rate-normalized virus loss, η = 1 - r v r , as a parameter. A practically relevant case is considered when the rate of virus loss is proportional to the permeation-driven mass flux of viruses to the membrane: d m ad dt ∼ Q p C f ≫ Q p C p . In this scenario, the instantaneous recovery is constant, the cumulative recovery is decreasing as a power function of time, R v = 1 - Q p V 0 t η , η mediates the trade-off between r and rv , and M is maximized at r = r opt = 1 2 η . The proposed model can guide the design of the sample concentration process and serve as a framework for quantification and interlaboratory comparison of experimental data on virus recovery.

Marine plastic pollution has a range of negative impacts for biota and the colonization of plastics in the marine environment by microorganisms may have significant ecological impacts. However, data on epiplastic organisms, particularly fungi, is still lacking for many ocean regions. To evaluate plastic associated fungi and their geographic distribution, we characterised plastics sampled from surface waters of the western South Atlantic (WSA) and Antarctic Peninsula (AP), using DNA metabarcoding of three molecular markers (ITS2, 18S rRNA V4 and V9 regions). Numerous taxa from eight fungal phyla and a total of 64 orders were detected, including groups that had not yet been described associated with plastics. There was a varied phylogenetic assemblage of predominantly known saprotrophic taxa within the Ascomycota and Basidiomycota. We found a range of marine cosmopolitan genera present on plastics in both locations, i.e., Aspergillus, Cladosporium, Wallemia and a number of taxa unique to each region, as well as a high variation of taxa such as Chytridiomycota and Aphelidomycota between locations. Within these basal fungal groups we identified a number of phylogenetically novel taxa. This is the first description of fungi from the Plastisphere within the Southern Hemisphere, and highlights the need to further investigate the potential impacts of plastic associated fungi on other organisms and marine ecosystems.

Trimethylamine (TMA) is common in marine environments. Although the presence of this compound in the oceans has been known for a long time, unlike the mammalian gastrointestinal tract, where TMA metabolism by microorganisms has been studied intensely, many questions remain unanswered about the microbial metabolism of marine TMA. This minireview summarizes what is currently known about the sources and fate of TMA in marine environments and the different pathways and enzymes involved in TMA metabolism in marine bacteria. This review also raises several questions about microbial TMA metabolism in the marine environments and proposes potential directions for future studies.

Boron-containing organic compounds are reported to have excellent luminescent properties, however, their ability to photosensitize singlet oxygen generation remains unexplored. The synthesis of several Schiff-base based boranils is reported, starting from commercially available salicylaldehydes and anilines. The iodo-functionalized derivatives were observed to aid in the photosensitized generation of singlet oxygen. Poly(methylmethacrylate) films incorporating these molecules were prepared and were demonstrated to be capable of serving as a reusable heterogeneous medium for the photosensitized degradation of organic water pollutants.

Mercury chloride exposure through drinking water in adult male prairie voles (Microtus ochrogaster) has been shown to alter their social behavior. Here, we examined the potential disruption of adult social behavior in prairie voles that were exposed to 60 ppm mercury during early development. We used a cross-fostering approach to test the effects of mercury exposure: (1) from conception until birth; (ii) from birth until weaning; and (iii) from conception until weaning, on adult affiliative behavior. Untreated and mercury-treated voles were given the option of remaining in an empty cage or affiliating with a same-sex conspecific in a 3-h choice test. We found that early developmental mercury exposure had little if any effect on the reproductive success of breeder pairs or on affiliative behavior by either sex when subjects were tested as adults. These results suggest that, at least in the context of the behavior tested, the effects of early developmental exposure to mercury do not permanently alter adult prairie vole affiliative behavior, or do so in a way that is too subtle to be detected using the current testing paradigm.

Fine sediment (particles

Draining of geographically isolated (no defined inlet or outlet) freshwater mineral soil wetlands has likely converted areas that acted historically as important P sinks to sources of P. To explore the role of wetland drainage on nonpoint-source P pollution, differences in the chemical characteristics and P sorption parameters of drained and intact wetlands were investigated in a small watershed situated in the Prairie Pothole Region of southwestern Manitoba, Canada. Chemical characteristics and P sorption parameters varied across landscape positions, particularly for landscape positions that were submerged. Intact wetlands had slightly higher concentrations of organic and total P relative to drained wetlands, which is indicative of their P trapping capacity. More importantly, the maximum P sorption capacity and P buffering capacity of intact wetlands were 3.6 (1752 vs. 492 mg kg) and 17 (1394 vs. 84 L kg) times greater than those in drained wetlands. Conversely, equilibrium P concentrations and bioavailable P concentrations in drained wetlands were an order of magnitude greater than those in intact prairie wetlands. Our study suggests that intact prairie wetlands may be effective sinks for P. As a result, prairie wetlands may play an important role in mitigating nonpoint-source pollution. Conversely, our findings suggest that drained prairie wetlands are potentially a high risk for P export and should be treated as important critical source areas within prairie watersheds.

Imidacloprid, a neonicotinoid insecticide, is a major component of hemlock woolly adelgid (HWA) [Adelges tsugae (Annand)] management programs that are critical to protecting forest health in the eastern United States. However, the impact of imidacloprid soil applications in forests on some aquatic macroinvertebrate species by leaching into aquatic systems is uncertain. The time for residues from imidacloprid soil applications to migrate from treated hemlocks to nearby streams and the concentrations at which imidacloprid may occur after initial migration is unknown. The presence and concentration of imidacloprid in three streams adjacent to recently treated hemlock (soil drench >10 m from stream channels) were assessed in the Big South Fork National River and Recreation Area. Two standard water grabs were collected monthly for 1 yr from a location downstream from imidacloprid-treated areas. Samples were analyzed using liquid chromatography tandem mass spectrometry (limit of detection = 0.025 μg L⁻¹). Imidacloprid was detected in all treatment streams during a single rain event that occurred 184 to 196 d after treatments, and concentrations ranged from 0.053 to 0.833 μg L⁻¹. Imidacloprid was not detected on any other sampling date from treatment streams. All observed positive detections exceeded the USEPA freshwater invertebrate chronic endpoint (0.01 μg L⁻¹). One stream sample exceeded the USEPA freshwater invertebrate acute endpoint (0.39 μg L⁻¹). However, previous macroinvertebrate community assessments in streams with similar concentrations did not indicate negative effects to aquatic fauna. These findings help characterize the risk of imidacloprid treatments to stream macroinvertebrates within 1 yr of soil applications.

Out-migrating steelhead Oncorhynchus mykiss from four Puget Sound rivers and associated marine basins of Puget Sound in Washington State were examined for the parasite, Nanophyetus salmincola in 2014 to determine whether recent trends in reduced marine survival are associated with the presence of this pathogen. A subset of steelhead from three of these river-marine basin combinations was analyzed for the presence of persistent organic pollutants (POPs) to assess whether exposure to these contaminants is a contributing factor to their reduced marine survival. The prevalence and parasite load of N. salmincola were significantly higher in fish from central and southern Puget Sound than in fish from river systems in northern Puget Sound. The proportion of steelhead samples with concentrations of POPs higher than adverse effects thresholds (AETs) or concentrations known to cause adverse effects was also greater in fish from the central and southern regions of Puget Sound than in those from the northern region. Polybrominated diphenyl ether concentrations associated with increased disease susceptibility were observed in 10% and 40% of the steelhead sampled from central and southern Puget Sound regions, respectively, but in none of the fish sampled from the northern region. The AET for polychlorinated biphenyls was exceeded in steelhead collected from marine habitats: 25% of the samples from the marine basins in the central and southern regions of Puget Sound and 17% of samples from northern Puget Sound region. Both N. salmincola and POP levels suggest there are adverse health effects on out-migrating steelhead from one southern and one central Puget Sound river that have lower early marine survival than those from a river system in northern Puget Sound.

Since the 1980s, gadolinium (Gd)-based contrast agents (GBCAs) have been routinely used in magnetic resonance imaging as stable chelates of the Gd3+ ion, without toxic effects. Generally, GBCAs are considered some of the safest contrast agents. However, it has been observed that they can accumulate in patient tissue, bone, and probably brain (causing nephrogenic systemic fibrosis in patients with kidney failure or insufficiency and disturbance of calcium homeostasis in the organism). The GBCAs are predominantly removed renally without metabolization. Subsequently, they do not undergo degradation processes in wastewater-treatment plants and are emitted into the aquatic ecosystem. Their occurrence was confirmed in surface waters (up to 1100 ng/L), sediments (up to 90.5 μg/g), and living organisms. Based on a literature review, there is a need to investigate the contamination of different ecosystems and to ascertain the environmental fate of Gd. Long-term ecotoxicological data, degradation, metabolism, bioaccumulation processes, and biochemical effects of the Gd complexes should be explored. These data can be used to assess detailed environmental risks because currently only hotspots with high levels of Gd can be marked as dangerous for aquatic environments according to environmental risk assessments. Environ Toxicol Chem 2018;37:1523-1534. © 2018 SETAC.

Sodium dodecyl sulfate coated amino-functionalized magnetic iron oxide nanoparticles were used as an efficient adsorbent for rapid removal and preconcentration of three important organophosphorus pesticides, chlorpyrifos, diazinon and phosalone, by ultrasound-assisted dispersive magnetic solid-phase microextraction. Fabrication of amino-functionalized magnetic nanoparticles was certified by characteristic analyses, including Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and transmission electron microscopy. Affecting parameters on the removal efficiency were investigated and optimized through half-fractional factorial design and Doehlert design, respectively. The analysis of analytes was performed by high-performance liquid chromatography with ultraviolet detection. Under the optimum conditions, extraction recoveries for 20 ng/mL of organophosphorus pesticides were in the range of 84-97% with preconcentration factors in the range of 134-155. Replicating the experiment in above condition for five times gave the relative standard deviations

Although marine and coastal environments which are contaminated with xenobiotic organic compounds often become hypoxic during the summer, the interactive effects of hypoxia and xenobiotic exposure on marine species such as teleost fishes remain poorly understood. The expression and activity of monooxygenase enzyme cytochrome P450-1A (CYP1A) in fishes are upregulated by exposure to polychlorinated biphenyls (PCBs), whereas they are down-regulated during hypoxia exposure. We investigated the interactive effects of hypoxia and PCB co-exposure on hepatic CYP1A expression in Atlantic croaker and on potential regulators of CYP1A. Croaker were exposed to hypoxia (1.7 mg/L dissolved oxygen), 3,3',4,4'-tetrachlorobiphenyl (PCB 77, dose: 2 and 8 µg/g body weight), and Aroclor 1254 (a common PCB mixture, dose: 0.5 and 1 µg/g body weight), alone and in combination for 4 weeks. PCB 77 exposure markedly increased hepatic CYP1A mRNA and protein expression, and ethoxyresorufin-O-deethylase (EROD, an indicator of CYP1A enzyme) activity and increased endothelial nitric oxide synthase (eNOS) protein expression. PCB 77 treatment also increased interleukin-1β (IL-1β, a cytokine) mRNA levels and protein carbonyl (PC, an indicator of reactive oxygen species, ROS) contents. These marked PCB 77- and Aroclor 1254-induced increases in CYP1A mRNA levels and EROD activity were significantly attenuated by co-exposure to hypoxia, whereas the increases in hepatic eNOS protein and IL-1β mRNA expression, and PC contents were augmented by hypoxia co-exposure. The results suggest that biotransformation of organic xenobiotics by CYP1A is reduced in fish during co-exposure to hypoxia and is accompanied by alterations in eNOS, ROS, and IL-1β levels.

Despite much research and investment into understanding and managing nutrients across agricultural landscapes, nutrient runoff to freshwater ecosystems is still a major concern. We argue there is currently a disconnect between the management of watershed surfaces (agricultural landscape) and river networks (riverine landscape). These landscapes are commonly managed separately, but there is limited cohesiveness between agricultural landscape-focused research and river science, despite similar end goals. Interdisciplinary research into stream networks that drain agricultural landscapes is expanding but is fraught with problems. Conceptual frameworks are useful tools to order phenomena, reveal patterns and processes, and in interdisciplinary river science, enable the joining of multiple areas of understanding into a single conceptual-empirical structure. We present a framework for the interdisciplinary study and management of agricultural and riverine landscapes. The framework includes components of an ecosystems approach to the study of catchment-stream networks, resilience thinking, and strategic adaptive management. Application of the framework is illustrated through a study of the Fox Basin in Wisconsin, USA. To fully realize the goal of nutrient reduction in the basin, we suggest that greater emphasis is needed on where best management practices (BMPs) are used within the spatial context of the combined watershed-stream network system, including BMPs within the river channel. Targeted placement of BMPs throughout the riverine landscape would increase the overall buffering capacity of the system to nutrient runoff and thus its resilience to current and future disturbances.

The contribution of macropore flow to phosphorus (P) loadings in tile-drained agricultural landscapes remains poorly understood at the field scale, despite the recognized deleterious impacts of contaminant transport via macropore pathways. A new subroutine that couples existing matrix-excess and matrix-desiccation macropore flow theory and a modified P routine is implemented in the Agricultural Policy Environmental eXtender (APEX) model. The original and modified formulation were applied and evaluated for a case study in a poorly drained field in Western Ohio with 31 months of surface and subsurface monitoring data. Results highlighted that a macropore subroutine in APEX improved edge-of-field discharge calibration and validation for both tile and total discharge from satisfactory and good, respectively, to very good and improved dissolved reactive P load calibration and validation statistics for tile P loads from unsatisfactory to very good. Output from the calibrated macropore simulations suggested median annual matrix-desiccation macropore flow contributions of 48% and P load contributions of 43%, with the majority of loading occurring in winter and spring. While somewhat counterintuitive, the prominence of matrix-desiccation macropore flow during seasons with less cracking reflects the importance of coupled development of macropore pathways and adequate supply of the macropore flow source. The innovative features of the model allow for assessments of annual macropore P contributions to tile drainage and has the potential to inform P site assessment tools.

The advent of real-time, short-term farm management tools is motivated by the need to protect water quality above and beyond the general guidance offered by existing nutrient management plans. Advances in high-performance computing and hydrologic or climate modeling have enabled rapid dissemination of real-time information that can assist landowners and conservation personnel with short-term management planning. This paper reviews short-term decision support tools for agriculture that are under various stages of development and implementation in the United States: (i) Wisconsin's Runoff Risk Advisory Forecast (RRAF) System, (ii) New York's Hydrologically Sensitive Area Prediction Tool, (iii) Virginia's Saturated Area Forecast Model, (iv) Pennsylvania's Fertilizer Forecaster, (v) Washington's Application Risk Management (ARM) System, and (vi) Missouri's Design Storm Notification System. Although these decision support tools differ in their underlying model structure, the resolution at which they are applied, and the hydroclimates to which they are relevant, all provide forecasts (range 24-120 h) of runoff risk or soil moisture saturation derived from National Weather Service Forecast models. Although this review highlights the need for further development of robust and well-supported short-term nutrient management tools, their potential for adoption and ultimate utility requires an understanding of the appropriate context of application, the strategic and operational needs of managers, access to weather forecasts, scales of application (e.g., regional vs. field level), data requirements, and outreach communication structure. USDA-NRCS Conservation Innovation Grants This review was supported, in part, by USDA-NRCS Conservation Innovation Grants to improve P indexing and modeling and to improve short-term forecasting tools for nutrient management planning.

This section presents a review of the literature published in 2016 on topics relating to distributed treatment systems. This review is divided into the following sections with multiple subsections under each: constituent removal; treatment technologies; and planning and treatment system management.

Standard methods for the evaluation of recreational water quality rely on generic bacterial indicators such as . However, does not provide enough information to determine fecal source or public health risk. The stsudy objective was to determine factors influencing the presence of and host-specific markers (HSM) from upstream to downstream in Beaver Lake Reservoir (BLR). From February 2014 to September 2015, 420 base flow and rain event samples were collected from seven sites-two sites from streams (White River [WR] and War Eagle Creek) draining into BLR and five sites from within BLR. Each sample was analyzed for and by quantitative polymerase chain reaction for HSM related to human, bovine, and poultry. The data indicate that overall levels of were significantly greater in the WR and significantly lower at the most downstream sampling location in BLR. is more likely present during spring (adjusted odds ratio [aOR] = 1.86), at the WR sampling site (aOR = 3.39), or during a rain event (aOR = 2.73). Moreover, the HSM HumM2 is more likely present (aOR = 1.99) when is present. These same factors were associated with concentrations >126 most probable number 100 mL (aOR = 2.76-12.48), except the poultry marker CL was more likely associated (aOR = 3.81) than HumM2. This study revealed that both seasonal and locational factors are important variables for fecal pollution in BLR. Moreover, these same factors may apply to fecal pollution in manmade reservoirs within similar types of watersheds across the United States, as well as internationally.

High grazing pressure can lead to soil erosion in pastures, causing increased sediment delivery to waterways. The objectives of this research were to evaluate the impact of grazing management and buffer strips on soil erosion by assessing soil physical properties, hydrology, and sediment loads from pastures fertilized with broiler litter. Field studies were conducted for 12 yr on 15 small watersheds. Five management strategies were evaluated: hayed (H), continuously grazed (CG), rotationally grazed (R), rotationally grazed with a buffer strip (RB), and rotationally grazed with a fenced riparian buffer (RBR). Broiler litter was applied every year at a rate of 5.6 Mg ha. Bulk density and penetration resistance were highest for CG watersheds. Runoff volumes, sediment concentrations, and loads were lowest for the H and RBR treatments and highest for CG. Average runoff amounts were 48, 84, 77, 60, and 81 mm yr for the H, R, RB, RBR, and CG treatments, respectively. Annual average sediment loads were 25, 30, 58, 71, and 110 kg ha for H, RBR, R, RB, and CG, respectively. The Revised Universal Soil Loss Equation, Version 2 was reasonably effective at predicting soil loss for the R, RB, and RBR treatments, but it greatly overpredicted soil loss from the CG and H treatments. Converting a pasture to a hay field or using rotational grazing in conjunction with a fenced riparian buffer appear to be effective options for reducing soil erosion and runoff to waterways from pasture soils.

Metal runoff from fields fertilized with poultry litter may pose a threat to aquatic systems. Buffer strips located adjacent to fields may reduce nutrients and solids in runoff. However, scant information exists on the long-term effects of buffer strips combined with grazing management on metal runoff from pastures. The objective of this study was to assess the 12-yr impact of grazing management and buffer strips on metal runoff from pastures receiving poultry litter. The research was conducted using 15 watersheds (25 m wide and 57 m long) with five treatments: hayed (H), continuously grazed (CG), rotationally grazed (R), rotationally grazed with a buffer strip (RB), and rotationally grazed with a fenced riparian buffer strip (RBR). Poultry litter was applied annually in spring at 5.6 Mg ha. Runoff samples were collected after every rainfall event. Aluminum (Al) and iron (Fe) concentrations were strongly and positively correlated with total suspended solids, indicating soil erosion was the primary source. Soluble Al and Fe were not related to total Al and Fe. However, there was a strong positive correlation between soluble and total copper (Cu) concentrations. The majority of total Cu and zinc was in water-soluble form. The CG treatment had the highest metal concentrations and loads of all treatments. The RBR and H treatments resulted in lower concentrations of total Al, Cu, Fe, potassium, manganese, and total organic carbon in the runoff. Rotational grazing with a fenced riparian buffer and converting pastures to hayfields appear to be effective management systems for decreasing concentrations and loads of metals in surface runoff from pastures fertilized with poultry litter.

peer-reviewed Carbon (C) losses from agricultural soils to surface waters can migrate through water treatment plants and result in the formation of disinfection by-products, which are potentially harmful to human health. This study aimed to quantify total organic carbon (TOC) and total inorganic C losses in runoff after application of dairy slurry, pig slurry, or milk house wash water (MWW) to land and to mitigate these losses through coamendment of the slurries with zeolite (2.36 3.35 mm clinoptilolite) and liquid polyaluminum chloride (PAC) (10% Al2O3) for dairy and pig slurries or liquid aluminum sulfate (alum) (8% Al2O3) for MWW. Four treatments under repeated 30-min simulated rainfall events (9.6 mm h-1) were examined in a laboratory study using grassed soil runoff boxes (0.225 m wide, 1 m long; 10% slope): control soil, unamended slurries, PAC-amended dairy and pig slurries (13.3 and 11.7 kg t-1, respectively), alum-amended MWW (3.2 kg t-1), combined zeolite and PAC-amended dairy (160 and 13.3 kg t-1 zeolite and PAC, respectively) and pig slurries (158 and 11.7 kg t-1 zeolite and PAC, respectively), and combined zeolite and alumamended MWW (72 and 3.2 kg t-1 zeolite and alum, respectively). The unamended and amended slurries were applied at net rates of 31, 34, and 50 t ha-1 for pig and dairy slurries and MWW, respectively. Significant reductions of TOC in runoff compared with unamended slurries were measured for PACamended dairy and pig slurries (52 and 56%, respectively) but not for alum-amended MWW. Dual zeolite and alum-amended MWW significantly reduced TOC in runoff compared with alum amendment only. We conclude that use of PAC-amended dairy and pig slurries and dual zeolite and alum-amended MWW, although effective, may not be economically viable to reduce TOC losses from organic slurries given the relatively low amounts of TOC measured in runoff from unamended slurries compared with the amounts applied. ACCEPTED peer-reviewed

Lowland waters in Northern Ireland experience elevated agricultural phosphorus (P) inputs, and in response a variety of control measures targeting farm nutrient management have been implemented. Their efficacy in lowering nitrogen (N) and P exports and improving water quality is examined in 40 headwater streams from 1990 to 2009, and to 2014 for 24 of these. Over this period manure production in the study catchments declined by 7%, but regional chemical fertilizer inputs declined by 37% for N and 79% for P, and the regional nutrient surplus was lowered by 18% for N and 49% for P. Diminished pollution by organic wastes meant that 85% of streams exhibited chemistry suitable for salmonids in 2009 compared to 40% in 1990. Flow-weighted mean concentrations (FWMCs) of nutrients declined between 1990 and 2009, and their correlations with catchment stocking rates became stronger over time. For catchments with manure inputs

We investigated the influence of dissolved calcium fluoride, CaF(aq), on the electrochemical dissolution of pyrite and the corresponding environmental effects on acid mine drainage (AMD). The experimental results showed that CaF(aq) promotes pyrite electrochemical dissolution. When the CaF(aq) concentration increased from 0 to 10 mg L up to saturation, the promoting efficiency was 15.80 and 57.25%, respectively. The reason for this phenomenon is that F and Fe form FeF, and at a higher scan potential, F and Fe form the ion complex FeF. The mechanisms include: (i) the decreasing charge transfer resistance at the double layer due to the iron fluorine complex formation; and (ii) the decreasing passivation resistance at the cover layer due to the strong penetration of F ions through it into the double layer. Although the hydrolysis reaction of F in solution could increase the pH value of mine drainage, the AMD was significantly aggravated because CaF(aq) promoted the pyrite electrochemical dissolution.

A three-dimensional water-stable cationic metal-organic framework (MOF) pillared by a neutral ligand and with Ni(II) metal nodes has been synthesized employing a rational design approach. Owing to the ordered arrangement of the uncoordinated tetrahedral sulfate (SO4 (2-) ) ions in the channels, the compound has been employed for aqueous-phase ion-exchange applications. The compound exhibits rapid and colorimetric aqueous-phase capture of environmentally toxic oxoanions (with similar geometries) in a selective manner. This system is the first example of a MOF-based system which absorbs both dichromate (Cr2 O7 (2-) ) and permanganate (MnO4 (-) ) ions, with the latter acting as a model for the radioactive contaminant pertechnetate (TcO4 (-) ).

The National Research Council has estimated that over 126,000 contaminated groundwater sites are unlikely to achieve low ug/L clean-up goals in the foreseeable future. At these sites, cost-effective, long-term monitoring schemes are needed in order to understand the long-term changes in contaminant concentrations. Current monitoring optimization schemes rely on site-specific evaluations to optimize groundwater monitoring frequency. However, when using linear regression to estimate the long-term zero-order or first-order contaminant attenuation rate, the effect of monitoring frequency and monitoring duration on the accuracy and confidence for the estimated attenuation rate is not site-specific. For a fixed number of monitoring events, doubling the time between monitoring events (e.g., changing from quarterly monitoring to semi-annual monitoring) will double the accuracy of estimated attenuation rate. For a fixed monitoring frequency (e.g., semi-annual monitoring), increasing the number of monitoring events by 60% will double the accuracy of the estimated attenuation rate. Combining these two factors, doubling the time between monitoring events (e.g., quarterly monitoring to semi-annual monitoring) while decreasing the total number of monitoring events by 38% will result in no change in the accuracy of the estimated attenuation rate. However, the time required to collect this dataset will increase by 25%. Understanding that the trade-off between monitoring frequency and monitoring duration is not site-specific should simplify the process of optimizing groundwater monitoring frequency at contaminated groundwater sites.

Groundwater quality assessment is essential for drinking from a security point of view. In this paper, a new evaluation method called toxicity combined fuzzy evaluation (TCFE) has been put forward, which is based on the fuzzy synthetic evaluation (FSE) method and the toxicity data from Agency for Toxic Substances and Disease Registry. The comparison of TCFE and FSE in the groundwater quality assessment of Guangzhou region also has been done. The assessment results are divided into 5 water quality levels; level I is the best while level V is the worst. Results indicate that the proportion of level I, level II, and level III used by the FSE method was 69.33% in total. By contrast, this proportion rose to 81.33% after applying the TCFE method. In addition, 66.7% of level IV samples in the FSE method became level I (50%), level II (25%), and level III (25%) in the TCFE method and 29.41% of level V samples became level I (50%) and level III (50%). This trend was caused by the weight change after the combination of toxicity index. By analyzing the changes of different indicators' weight, it could be concluded that the better-changed samples mainly exceeded the corresponding standards of regular indicators and the deteriorated samples mainly exceeded the corresponding standards of toxic indicators. The comparison between the two results revealed that the TCFE method could represent the health implications of toxic indicators reasonably. As a result, the TCFE method is more scientific in view of drinking safety.

Resistance to semi-dry environments has been considered a crucial trait for superior growth and survival of strains used for bioaugmentation in contaminated soils. In order to compare water stress programmes, we analyse differential gene expression among three phylogenetically different strains capable of aromatic compound degradation: Arthrobacter chlorophenolicus A6, Sphingomonas wittichii RW1 and Pseudomonas veronii 1YdBTEX2. Standardized laboratory-induced water stress was imposed by shock exposure of liquid cultures to water potential decrease, induced either by addition of solutes (NaCl, solute stress) or by addition of polyethylene glycol (matric stress), both at absolute similar stress magnitudes and at those causing approximately similar decrease of growth rates. Genome-wide differential gene expression was recorded by micro-array hybridizations. Growth of P. veronii 1YdBTEX2 was the most sensitive to water potential decrease, followed by S. wittichii RW1 and A. chlorophenolicus A6. The number of genes differentially expressed under decreasing water potential was lowest for A. chlorophenolicus A6, increasing with increasing magnitude of the stress, followed by S. wittichii RW1 and P. veronii 1YdBTEX2. Gene inspection and gene ontology analysis under stress conditions causing similar growth rate reduction indicated that common reactions among the three strains included diminished expression of flagellar motility and increased expression of compatible solutes (which were strain-specific). Furthermore, a set of common genes with ill-defined function was found between all strains, including ABC transporters and aldehyde dehydrogenases, which may constitute a core conserved response to water stress. The data further suggest that stronger reduction of growth rate of P. veronii 1YdBTEX2 under water stress may be an indirect result of the response demanding heavy NADPH investment, rather than the presence or absence of a suitable stress defence mechanism per se.