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The objective of this paper was to study MEC performance at steady-state conditions in continuous mode and to analyse MEC performance in terms of chemical efficiency. At steady-state operation, a current density of 10.2 A m −2 (applied voltage 1.0 V) for a set-up with an AEM was produced, compared to 7.2 A m −2 for a set-up with a CEM. For all applied voltages, total internal resistance for the AEM configuration was lower than or the CEM configuration. Therefore, energy input for the AEM configuration is lower than for the CEM configuration. In case a CEM is used, the conductivity in the cathode reaches high values: >130 mS cm −1 . This conductivity is mainly caused by the presence of Na + (7.8 g L −1 ), K + (12.2 g L −1 ) and OH − (8.3 g L −1 ). Furthermore, MECs perform better at high buffer and electrolyte concentrations. However, as current density does not increase proportionally with increase in chemicals, the effectiveness of chemical addition decreases when more chemicals are added. Therefore, addition of chemicals and buffer does not necessarily enhance performance but increases operational costs.

Removal of the toxic selenium compounds selenite and selenate from waste water before discharge is becoming increasingly imperative in industrialized countries. Bacteria can reduce selenate to selenite, but also further to elemental selenium, selenide or organic selenium. In this paper, we aim to exclusively bio-reduce selenate to selenite in an open high-rate bioreactor. This conversion could be part of a two-stage process in which the selenite is subsequently reduced by chemical means under optimal conditions to produce a biomass-free selenium product. In the process, yield and reduction rate of biological selenate to selenite should be maximized, while formation of elemental selenium, selenide and organic selenium compounds should be avoided. Fed-batch experiments with a liquid volume of 0.25–0.75 L at different temperatures 20–30–40–50 °C, pH settings 6–7–8–9, initial biomass concentration of 1 or 5 g wet weight granular Eerbeek sludge and various lactic acid concentrations were performed to determine their effect on the biological conversion of selenate to selenite. Furthermore, the effect on selenite losses by further biological reduction or, if present, chemical reduction was investigated as well. Optimal selenate reduction to selenite was found at 30 °C and pH 6 or 7 or 8 with 25 mM selenate and 13.75 mM lactic acid in the influent, with a selenite yield of 79–95%. In all the other conditions, less selenate was reduced to selenite. Also a 5 times higher electron donor concentration resulted in less selenite production, with only 22% of the selenate converted to selenite. The high yield and the high biological reduction rate of at least 741 mg Se/g initial VSS/day detected in the 1 g initial biomass experiment implicate that biological selenate conversion to selenite is a feasible process.

This paper reports the effect of employing Ni & Sb oxide precursors ( instead of chlorides) in the preparation of Ni/Sb-SnO2 anodes on the activity and selectivity of ozone production in 1.0M HClO4. The effect of catalyst loading, Ni content in the precursor solution, furnace temperature and constant current density vs constant cell voltage operation is reported. The optimum composition was found to be Sn: Sb: Ni = 100: 6: 1, giving a maximum current efficiency of ca. 38% at a current density of 100 mA cm(-2), the latter higher than previously reported. The durability of anodes prepared using NiO and Sb2O3 at 550 degrees C during electrolysis at 100 mA cm(-2) in 1M HClO4 was found to be 200 hours, again significantly higher than Ni/Sb-SnO2 anodes prepared using the chloride precursors at lower temperatures. Damascus University, Syria

This paper presents a screening tool for the location-specific prioritization of human pharmaceutical emissions in Europe, based on risk quotients for the aquatic environment and human health. The tool provides direction towards either monitoring activities or additional research. Its application is illustrated for a set of 11 human antibiotics and 7 antineoplastics. Risk quotients for the aquatic environment were highest for levofloxacin, doxycycline and ciprofloxacin, located in Northern Italy (Milan region; particularly levofloxacin) and other densely populated areas in Europe (e.g. London, Krakow and the Ruhr area). Risk quotients for human health not only depend on pharmaceutical and location, but also on behavioral characteristics, such as consumption patterns. Infants in eastern Spain that consume locally produced food and conventionally treated drinking water were predicted to run the highest risks. A limited comparison with measured concentrations in surface water showed that predicted and measured concentrations are approximately within one order of magnitude. Keywords: Pharmaceuticals, Prioritization, Risk assessment, Environment, Human health, Spatial variation

Phosphorus losses from agricultural soils is an important source of P in surface waters leading to surface water quality impairment. In addition to reducing P inputs, mitigation measures are needed to reduce P enrichment of surface waters. Because drainage of agricultural land by pipe drainage is an important pathway of P to surface waters, removing P from drainage water has a large potential to reduce P losses. In a field trial, we tested the performance of a pipe drain enveloped with Fe-coated sand, a side product of the drinking water industry with a high ability to bind P, to remove P from the drainage water. The results of this trial, encompassing more than one hydrological season, are very encouraging because the efficiency of this mitigation measure to remove P amounted to 94%. During the trial, the pipe drains were below the groundwater level for a prolonged time. Nevertheless, no reduction of Fe(III) in the Fe-coated sand occurred, which was most likely prevented by reduction of Mn oxides present in this material. The enveloped pipe drain was estimated to be able to lower the P concentration in the effluent to the desired water quality criterion for about 14 yr. Manganese oxides are expected to be depleted after 5 to 10 yr. The performance of the enveloped pipe drain, both in terms of its ability to remove P to a sufficiently low level and the stability of the Fe-coated sand under submerged conditions in the long term, needs prolonged experimental research.

A method was developed and validated for the analysis of benzene, toluene, ethylbenzene, xylene (BTEX), and styrene in sea water samples using gas chromatography-mass spectrometry (GC-MS) with static headspace extraction. To carefully characterize the performance of this method, several factors affecting the parameters were studied in detail, such as the heating procedure, loop filling time, equilibrium temperature, the sample dilution ratio, equilibrium, and injection times. The optimized conditions are as follows: 1)the heating procedure, 50 degrees C for 4 min, then increased to 170 degrees C at 15 degrees C min-1, 2) equilibrium temperature, 60 degrees C, 3) equilibrium time, 5 min, and 4) injection time 0.5 min. Under the optimized conditions, the linear equations were obtained in the concentration range of 10 - 50 /kg L-1 with good correlation coefficient values. The limits of detection were 1.8 - 3.3 mu g L-1. The recoveries at the spiked level of 20 mu g L-1 BTEX and styrene ranged from 97% - 103% with the relative standard deviations were (RSD, n=3) 1.0% - 7.6%. The method was used for seawater samples from the Marmara Mudanya region. Deniz suyundaki benzen, toluen, etilbenzen, ksilen ve stiren bileşenlerinin tayininde gaz kromatografisi metodu kullanılmaktadır. Bunun için örnekler statik buhar faz ekstraksiyon yöntemiyle gaz faza alınıp gaz kromatografisi kütle spektrometresine enjekte edilmektedir. Analiz sonuçlarına etki edebilecek parametrelerden en önemlileri araştırılarak, gerçek deniz suyu örneğinin film kompozisyonu en önemli faktör olarak saptanmıştır. Cihazda kullanılan fırın programı; 50°C, 4 dk boyunca, 15°C dk-1 artış hızı ile 170°C’ ye ısınma şeklindedir. Enjektör sıcaklığı 280°C’ dir. Optimize edilen şartlarda, kullanılan analitik bölge aralığında (10-50 μg L-1), yüksek korelasyon katsayıları elde edilmiştir. Gözlenebilme sınırları 1,8-3,3 μg L-1 aralığındadır. Geri kazanım verimleri, 20 μg L-1 katılımlar için %97’nin üzerinden bulunurken, bağıl standart sapmalar ise %1 ile %8 arasında değişmektedir. Geliştirilen yöntem Marmara Denizi Mudanya kıyılarından alınan deniz suyu örneklerine uygulanmıştır.

Several membrane fouling mechanisms have been identified in membrane bioreactors. While cake layers can be removed by physical cleaning, irreversible fouling such as a gel layer is difficult to remove by physical cleaning during filtration. Harsh mechanical cleaning was applied in this study to evaluate how much fouling could be maximally removed and distribution of remaining fouling was investigated. The fouling resistance of several membranes operated at different relatively low fluxes was followed during long term continuous flux operation. Remaining fouling was observed with scanning electron microscopy (SEM) and magnetic resonance imaging (MRI). Dead-end filtration tests with mechanically cleaned membranes showed a decreased permeability. To determine whether bacteria were present in the remaining fouling, oxygen consumption was quantified. Even after harsh mechanical cleaning, membrane samples showed considerable oxygen consumption. SEM did not show fouling inside the membrane. Of several membranes operated for at least 1 year, the permeate side was covered with bacteria and extracellular polymeric substances (EPS). These results show that fouling cannot be removed completely by harsh mechanical cleaning and that both feed and permeate side of the membrane contains biofouling. This fouling on the permeate side should not be neglected when designing membrane cleaning.

Nutrient balances are useful indicators to assess the sustainability of farming systems. This study study investigates inflow and outflow of major nutrients in urban and periurban production systems in Kano, Nigeria. To this end, 16 households representing three different urban and peri-urban (UPA) farming systems were studied using the MONQI toolbox (formerly known as NUTMON) to calculate nutrient flows and economic performances. The farm nitrogen (N) balance was positive at 56.6, 67.4 and 56.4 kg farm-1 year-1 for commercial garden and crop-livestock (cGCL), commercial gardening and semi-commercial livestock (cGscL) and commercial livestock subsistence field cropping (cLsC) farm types, respectively. The same trend was observed for phosphorus (P) and potassium (K) in all farm types except an annual negative K balance of 16 kg farm-1 in cGCL. Across the different activities within the farms, land uses had positive N (359, 387 and 563 kg N ha-1 year-1) and P (74, 219 and 411 kg P ha-1 year-1) balances for all farm types, but again a negative K balance in cGCL with an average loss of 533 kg K ha-1 year-1. Partial nutrient balances in livestock production indicated a positive balance for all nutrients across the farms types but were slightly negative for P in cLsC. Commercial livestock keeping (cLsC) was economically more profitable than the other farm types with an average annual gross margin (GM) and net cash flow (NCF) of 9,033and 935. Cropping activities within cGCL and cGscL had GMs of 1,059and 194 and NCFs of 757and 206, respectively, but livestock activities in both farm types incurred financial losses. Potassium inputs were limited under vegetable and crop production of cGCL, threatening long-term K nutrient availability in this system. Overall, the results indicated large annual surpluses of N and P in urban and peri-urban vegetable and crop production systems which pose a potential threat when lost to the environment. Appropriate policies should aim at promoting sustainable production through efficient nutrient management in the Kano UPA sector.

The effects of sulfathiazole (STA) on Escherichia coli with glucose as a growth substrate was investigated to elucidate the effect-based reaction of sulfonamides in bacteria and to identify biomarkers for bacterial uptake and effect. The predominant metabolite was identified as pterine-sulfathiazole by LC-high resolution mass spectrometry. The formation of pterine-sulfathiazole per cell was constant and independent of the extracellular STA concentrations, as they exceeded the modeled half-saturation concentration K M S of 0.011 μmol L−1. The concentration of the dihydrofolic acid precursor para-aminobenzoic acid (pABA) increased with growth and with concentrations of the competitor STA. This increase was counteracted for higher STA concentrations by growth inhibition as verified by model simulation of pABA dynamics. The EC value for the inhibition of pABA increase was 6.9 ± 0.7 μmol L−1 STA, which is similar to that calculated from optical density dynamics indicating that pABA is a direct biomarker for the SA effect.

International audience; A coupled process was studied for the removal of a chlorinated pesticide: 2,4-Dichlorophenoxyacetic acid (2,4-D). A home-made electrochemical flow cell was used for the pre-treatment and a biological treatment was then carried out using activated sludge supplied by a local wastewater treatment plant. 2,4-D was used as a target compound for the study. Several parameters were monitored during the biological treatment, like dissolved organic carbon (DOC), the target compound and the major by-product. Pretreatment led to a quick decrease of DOC during the biological process, since a 66% mineralization yield was measured after the second day, and 79% after the seventh day of culture. After two days of treatment, HPLC results revealed a total degradation of Chlorohydroquinone, the major by-product. The electrochemical pretreatment shortened the length of the biological treatment, since DOC measurements showed that in the case of non-pretreated 2,4-D, no mineralization was observed before day 7. These promising results should be subsequently confirmed on commercial 2,4-D-containing solutions and then on real effluents.

Bio-recalcitrant micropollutants are often insufficiently removed by modern wastewater treatment plants to meet the future demands worldwide. Therefore, several advanced oxidation techniques, including cold plasma technology, are being investigated as effective complementary water treatment methods. In order to permit industrial implementation, energy demand of these techniques needs to be minimized. To this end, we have developed an electrical discharge reactor where water treatment by dielectric barrier discharge (DBD) is combined with adsorption on activated carbon textile and additional ozonation. The reactor consists of a DBD plasma chamber, including the adsorptive textile, and an ozonation chamber, where the DBD generated plasma gas is bubbled. In the present paper, this reactor is further characterized and optimized in terms of its energy efficiency for removal of the five pesticides α-HCH, pentachlorobenzene, alachlor, diuron and isoproturon, with initial concentrations ranging between 22 and 430 μg/L. Energy efficiency of the reactor is found to increase significantly when initial micropollutant concentration is decreased, when duty cycle is decreased and when oxygen is used as feed gas as compared to air and argon. Overall reactor performance is improved as well by making it work in single-pass operation, where water is flowing through the system only once. The results are explained with insights found in literature and practical implications are discussed. For the used operational conditions and settings, α-HCH is the most persistent pesticide in the reactor, with a minimal achieved electrical energy per order of 8 kWh/m3, while a most efficient removal of 3 kWh/m3 or lower was reached for the four other pesticides.

Record-breaking floods in September 2013 caused massive damage to homes and infrastructure across the Colorado Front Range and heavily impacted the Cache La Poudre River watershed. Given the unique nature of this watershed as a test-bed for tracking environmental pathways of antibiotic resistance gene (ARG) dissemination, we sought to determine the impact of extreme flooding on ARG reservoirs in river water and sediment. We utilized high-throughput DNA sequencing to obtain metagenomic profiles of ARGs before and after flooding, and investigated 23 antibiotics and 14 metals as putative selective agents during post-flood recovery. With 277 ARG subtypes identified across samples, total bulk water ARGs decreased following the flood but recovered to near pre-flood abundances by ten months post-flood at both a pristine site and at a site historically heavily influenced by wastewater treatment plants and animal feeding operations. Network analysis of de novo assembled sequencing reads into 52,556 scaffolds identified ARGs likely located on mobile genetic elements, with up to 11 ARGs per plasmid-associated scaffold. Bulk water bacterial phylogeny correlated with ARG profiles while sediment phylogeny varied along the river’s anthropogenic gradient. This rare flood afforded the opportunity to gain deeper insight into factors influencing the spread of ARGs in watersheds.

A comprehensive mechanistic model for describing algal growth dynamics in a photobioreactor was developed in this work with state of the art understanding and realistic assumptions for major associated processes. The model included 27 state variables related to various algal processes. This model was validated with extensive experimental data obtained from independent growth experiments in batch reactors, and was able to simulate system performance reasonably well. The comprehensive nature of the formulation also highlights the complex inter-relationship between all processes, and provides a tool for gaining more systematic insights into algal behavior in photobioreactors and other such systems. (C) 2017 Elsevier Ltd. All rights reserved.

Anaerobic digestion of high-salinity wastewaters often results in process inhibition due to the susceptibility of the methanogenic archaea. The ability of the microbial community to deal with increased salinity levels is of high importance to ensure process perseverance or recovery after failure. The exact strategy of the microbial community to ensure process endurance is, however, often unknown. In this study, we investigated how the microbial community is able to recover process performance following a disturbance through the application of high-salinity molasses wastewater. After a stable start-up, methane production quickly decreased from 625 +/- 17 to 232 35 mL CH4 L-1 d(-1) with a simultaneous accumulation in volatile fatty acids up to 20.5 +/- 1.4 g COD L-1, indicating severe process disturbance. A shift in feedstock from molasses wastewater to waste activated sludge resulted in complete process recovery. However, the bacterial and archaeal communities did not return to their original composition as before the disturbance, despite similar process conditions. Microbial community diversity was recovered to similar levels as before disturbance, which indicates that the metabolic potential of the community was maintained. A mild increase in ammonia concentration after process recovery did not influence methane production, indicating a well-balanced microbial community. Hence, given the change in community composition following recovery after salinity disturbance, it can be assumed that microbial community redundancy was the major strategy to ensure the continuation of methane production, without loss of functionality or metabolic flexibility.

Hydraulic fracturing has advanced the development of shale gas extraction, while inadvertent spills of flowback water may pose a risk to the surrounding environment due to its high salt content, metals/metalloids (As, Se, Fe and Sr), and organic additives. This study investigated the potential impact of flowback water on four representative soils from shale gas regions in Northeast China using synthetic flowback solutions. The compositions of the solutions were representative of flowback water arising at different stages after fracturing well establishment. The effects of solution composition of flowback water on soil ecosystem were assessed in terms of metal mobility and bioaccessibility, as well as biological endpoints using Microtox bioassay (Vibrio fischeri) and enzyme activity tests. After one-month artificial aging of the soils with various flowback solutions, the mobility and bioaccessibility of As(V) and Se(VI) decreased as the ionic strength of the flowback solutions increased. The results inferred a stronger binding affinity of As(V) and Se(VI) with the soils. Nevertheless, the soil toxicity to Vibrio fischeri only presented a moderate increase after aging, while dehydrogenase and phosphomonoesterase activities were significantly suppressed with increasing ionic strength of flowback solutions. On the contrary, polyacrylamide in the flowback solutions led to higher dehydrogenase activity. These results indicated that soil enzyme activities were sensitive to the composition of flowback solutions. A preliminary human health risk assessment related to As(V) suggested a low level of cancer risk through exposure via ingestion, while holistic assessment of environmental implications is required.

The susceptibility for photon-induced degradation of over 800 pharmaceutical compounds present in the LOPAC(1280) library, was analyzed by UV/Vis spectroscopy in the absence or presence of TiO2 P25 in water. In general, few compounds were effectively degraded in the absence of the TiO2 photocatalyst (3% of all compounds tested), while in the presence of TiO2, the majority of compounds was converted, often to a large degree. Differences in degree of degradation are evaluated on the basis of molecular weight, as well as the chemical nature of the drug compounds (functional groups and pharmacological classes). In general, if the molecular weight increases, the degradation efficacy decreases. Relatively high degrees of conversion can be achieved for (relatively small) molecules with functional groups such as aldehydes, alcohols, ketones and nitriles. A low degree of conversion was observed for compounds composed of conjugated aromatic systems. Trends in degradation efficacy on the basis of pharmacological class, e.g. comparing hormones and opioids, are not obvious. (C) 2016 Elsevier Ltd. All rights reserved.

An increased number of suspected outbreaks of gastroenteritis linked to bathing water were reported to the Finnish food- and waterborne outbreak (FWO) registry in July and August 2014. The investigation reports were assessed by a national outbreak investigation panel. Eight confirmed outbreaks were identified among the 15 suspected outbreaks linked to bathing water that had been reported to the FWO registry. According to the outbreak investigation reports, 1,453 persons fell ill during these outbreaks. Epidemiological and microbiological data revealed noroviruses as the main causative agents. During the outbreaks, exceptionally warm weather had boosted the use of beaches. Six of eight outbreaks occurred at small lakes; for those, the investigation strongly suggested that the beach users were the source of contamination. In one of those eight outbreaks, an external source of contamination was identified and elevated levels of faecal indicator bacteria (FIB) were noted in water. In the remaining outbreaks, FIB analyses were insufficient to describe the hygienic quality of the water. Restrictions against bathing proved effective in controlling the outbreaks. In spring 2015, the National Institute for Health and Welfare (THL) and the National Supervisory Authority for Welfare and Health (Valvira) published guidelines for outbreak control to prevent bathing water outbreaks.

In this paper, a one-pot and easy-to-handle method at room temperature without additional chemicals for the modification of graphene oxide (GO) with surfactant is found. Removal of nickel (II) ions from aqueous solutions by GO and surfactant (sodium dodecyl sulphate) modified graphene oxide (SDS-GO) was studied spectrophotometrically at room temperature as a function of time, initial concentration and pH. Adsorption capacity of the adsorbent was increased dramatically (from 20.19 to 55.16 mg/g found by Langmuir model) due to the functionalization of the surface by SDS. The driving force of the adsorption of Ni(II) ions is electrostatic attraction and Ni(II) ions adsorbed on the GO surface chemically besides ion exchange.

Copper is a major problem in industrial wastewater streams, seriously affecting the quality of potential drinking water. Several approaches, including continuous membrane processes or batch-wise application of adsorbents, are in use to tackle this problem. Unfortunately, these processes suffer from their particular drawbacks, such as low permeance or disposal of saturated adsorbents. However, a combination of these processes could constitute a step towards a more efficient copper removal solution. Here, we present a nanopaper ion-exchanger prepared from cellulose nanofibrils produced from fibre sludge, a paper industry waste stream, for the efficient, continuous removal of copper from aqueous solutions. This nanopaper ion-exchanger comprises phosphorylated cellulose nanofibrils that were processed into nanopapers by papermaking. The performance of these phosphorylated nanopaper membranes was determined with respect to their rejection of copper and permeance. It was shown that this new type of nanopaper is capable of rejecting copper ions during a filtration process by adsorption. Results suggest that functional groups on the surface of the nanopapers contribute to the adsorption of copper ions to a greater extent than phosphate groups within the bulk of the nanopaper. Moreover, we demonstrated that those nanopaper ion-exchangers could be regenerated and reused and that in the presence of calcium ions, the adsorption capacity for copper was only slightly reduced.

Heterogeneous photocatalysis with TiO2 has shown high efficiency in the removal of a wide range of organic contaminants. Recently, significant efforts have been made to activate TiO2 under visible light wavelengths, and promising results were obtained by doping it with nitrogen. The main drawback of the use of nanoparticles for the purification of wastewater is their separation after the depollution treatment and this is an issue that has to be addressed for a proficient application of N-doped TiO2 nanoparticles. The use of magnetic core Fe3O4 and N-doped TiO2 shell nanoparticles could be a solution to this problem. With the aid of an external magnetic field, the removal and recycling of the photocatalyst nanoparticles become possible. For this reason, the aim of this work was to obtain nanocomposites consisting of visible active N-doped TiO2 supported on SiO2/Fe3O4 ferromagnetic nanoparticles. The nanocomposites were then evaluated in the photocatalytic removal of phenol. The photocatalytic tests were carried out in a recirculating batch cylindrical photoreactor irradiated by a strip of white LEDs surrounding the external surface of the reactor and emitting in the visible region. The experimental results showed that N-doped TiO2/SiO2/Fe3O4 nanoparticles are effective in the removal of phenol, reaching degradation and TOC removal of about 64 and 55%, respectively, after an irradiation time of 270 min. The catalyst was collected at the photoreactor bottom after each test cycle by applying a magnet on the external surface of the photoreactor, so easily separating the treated solution from the photocatalyst. After washing with distilled water and drying at 50 °C, the photocatalyst was reused without further treatment. Photocatalytic tests on the recycled catalyst showed that N-doped TiO2/SiO2/Fe3O4 remains stable, evidencing phenol degradation in the range 59-65% after four operation/regeneration cycles.

Hydrogen Sulfide (H2S) is an odourous, highly toxic gas commonly encountered in various commercial and municipal sectors. Three novel, laboratory-scale, Horizontal-Flow Biofilm Reactors (HFBRs) were tested for the removal of H2S gas from air streams over a 178-day trial at 10 degrees C. Removal rates of up to 15.1 g [H2S] m(-3) h(-1) were achieved, demonstrating the HFBRs as a feasible technology for the treatment of H2S-contaminated airstreams at low temperatures. Bio-oxidation of H2S in the reactors led to the production of H+ and sulfate (SO42-) ions, resulting in the acidification of the liquid phase. Reduced removal efficiency was observed at loading rates of 15.1 g [H2S] m(-3) h(-1). NaHCO3 addition to the liquid nutrient feed (synthetic wastewater (SWW)) resulted in improved H2S removal. Bacterial diversity, which was investigated by sequencing and fingerprinting 16S rRNA genes, was low, likely due to the harsh conditions prevailing in the systems. The HFBRs were dominated by two species from the genus Acidithiobacillus and Thiobacillus. Nonetheless, there were significant differences in microbial community structure between distinct HFBR zones due to the influence of alkalinity, pH and SO4 concentrations. Despite the low temperature, this study indicates HFBRs have an excellent potential to biologically treat H2S-contaminated airstreams. This work was supported by Science Foundation Ireland [grant number 08/RFP/ENM1762] and a European Research Council Starting Grant (3C-BIOTECH; no. 261330). peer-reviewed

During the investigation it was observed that waste water regularly (WWR) used for irrigation of crop show adverse effect on plants growth and yield, thus significantly increased the disease intensity as compared to occasionally used waste water (WWO) and ground water (GW). WWR suppressed the growth of fennel plant and showed highest increase in disease intensity but the yield of crop was decreased gradually. The highest disease intensity was observed in Fusarium wilt disease caused by Fusarium sp. followed by stem gall. WWO showed the moderate (++) plant growth in comparison to normal growth of plants irrigated with GW and suppressed growth of crop irrigated by WWR. The WWO increased the total yield of crop followed by GW and showed the slightly decreased disease intensity except Fusarium wilt due to their composition of minerals which is necessary for plant growth. The study reveals that the high quantity of inorganic minerals was presented in WW followed by soil and GW respectively. The regular irrigation of crop by WWR showed the high accumulation of soil toxins and inorganic minerals in the field caused high disease intensity and poor growth yield of fennel crop as compared to irrigation by WWO and GW.

Growing travel and trade threatens biodiversity as it increases the rate of biological invasions globally, either by accidental or intentional introduction. Therefore, avoiding these impacts by forecasting invasions and impeding further spread is of utmost importance. In this study, three forecasting approaches were tested and combined to predict the invasive behaviour of the alien macrophyte Lemna minuta in comparison with the native Lemna minor: the functional response (FR) and relative growth rate (RGR), supplemented with a combined biomass-based nutrient removal (BBNR). Based on the idea that widespread invasive species are more successful competitors than local, native species, a higher FR and RGR were expected for the invasive compared to the native species. Five different nutrient concentrations were tested, ranging from low (4 mgN.L-1 and 1 mgP.L-1) to high (70 mgN.L-1 and 21 mgP.L-1). After four days, a significant amount of nutrients was removed by both Lemna spp., though significant differences among L. minor and L. minuta were only observed at lower nutrient concentrations (lower than 17 mgN.L-1 and 6 mgP.L-1) with higher nutrient removal exerted by L. minor. The derived FR did not show a clear dominance of the invasive L. minuta, contradicting field observations. Similarly, the RGR ranged from 0.4 to 0.6 d-1, but did not show a biomass-based dominance of L. minuta (0.5 ± 0.1 d-1 versus 0.63 ± 0.09 d-1 for L. minor). BBNR showed similar results as the FR. Contrary to our expectations, all three approaches resulted in higher values for L. minor. Consequently, based on our results FR is sensitive to differences, though contradicted the expectations, while RGR and BBNR do not provide sufficient power to differentiate between a native and an invasive alien macrophyte and should be supplemented with additional ecosystem-based experiments to determine the invasion impact.

The feasibility of continuous phosphate recovery, by adsorption on powdered Ca-activated zeolite (PAZ), was assessed in a hybrid sorption membrane ultrafiltration (UF) system. The objective was to explore the influence of process parameters such as initial P(V) concentration, pH, and PAZ dose on P(V) recovery from a tertiary treatment effluent. The hydrodynamic parameters of the UF operation were also evaluated as a function of the PAZ dose. The P(V) recovery profiles as a function of the initial P(V) concentrations, at pH 8 and 2.5 gpAz/L, indicated that the sorbent was not saturated, and recoveries reported were 1.8 +/- 0.2, 5.7 +/- 0.3, and 47.2 +/- 2 mg P(V)/gpAz for 10 +/- 1, 25 2, and 100 +/- 6 mg P(V)/L, respectively. The increase of the pH of the feed solution from 8 to 9 increased the P(V) recovery up to 70 4%. A P(V) fractionation protocol of the loaded samples confirmed that the phosphate -sorption process involves the formation of calcium phosphate mineral forms

Hydroxyapatite (Ca-10(PO4)(6)(OH)(2), HAp) is a calcium phosphate employed both in biomedicine and for environmental remediation. It is known that HAp can also be photocatalytic under UV light, probably due to oxygen deficiencies, but the mechanism is unclear, and reported optical band gap energies vary greatly. For the first time we propose the mechanisms and precise kinds of vacancies which may cause the photocatalytic activity of HAp, and compare these theoretical data with our measured data on both samples of marine origin and commercial HAp powders. Density functional theory (DFT) (from first principles calculations and Density of States (DOS) modelling) was used to calculate the optical band gap energy (E-g) created by various possible oxygen vacancies in the HAp lattice: O from PO4, O from OH, the loss of an entire OH group, or the simultaneous loss of O from PO4 and an entire OH group. The modelled values match the measured values very closely, suggesting that in non-photocatalytic HAp, if any vacancies exist, they are O atoms from the OH group, resulting in a band gap of similar to 5 eV in the UVC region (not present in solar light at the Earth's surface). However, in photocatalytic HAp, reduction from the combustion of an organic component at 1000 degrees C led to oxygen deficiency in the phosphate groups, probably in the O15 position, giving an E-g of similar to 3.45 eV, in the UVA region (present in sunlight). Heating HAp with no organic component to 1200 degrees C also led to vacancies, of both an entire OH group and oxygen from PO4 groups, which led to an intermediate Eg value of similar to 4 eV, on the boundary of the UVA-UVB regions. Absorption peaks were also predicted in the visible-light region with some types of vacancy. (C) 2016 Elsevier B.V. All rights reserved.

BACKGROUND: This study evaluated a polymeric ion exchanger impregnated with nanoparticles of hydrated ferric oxide as a selective sorbent for anionic P(V) species. The hybrid impregnated anion exchanger (HAIX) employed as sorbent combines the durability and mechanical strength of a polymeric weak base anion exchange resin with the high sorption affinity of hydrated ferric oxide towards P(V) species.; RESULTS: The P(V) loading capacity of the sorbent at a pH simulating the expected conditions in treated wastewaters was 92+/-3mg P-PO4 g(-1) in single component solutions. The sorption of P(V) is affected slightly by the common ions typically present in these effluents such as Cl-, SO42- and NO3-, and a reduction of only 5% was observed (89+/-2 mg P-PO4 g(-1)) in multicomponent solutions. The sorbent can be regenerated (95+/-3%) using 4% (w/w) sodium hydroxide solution.; CONCLUSIONS: HAIX displays high selectivity for phosphate and small affinity for SO42-, NO3- and Cl- ions, which provides excellent conditions for its application at pH values typical of secondary wastewater effluents. HAIX exhibits higher and competitive phosphate removal capacity compared with data reported in the literature for materials based on HFO and for adsorbents prepared by impregnation of HFO onto polymeric supports. (C) 2015 Society of Chemical Industry

In this study, Portuguese clay, Fe-impregnated clay, red mud and clay/red mud mixtures were used in the removal of Acid Orange 7 by Fenton and photo-Fenton (under UV light) oxidation processes. In comparison with pure adsorption, the catalytic activity of Fe-loaded clay showed an optimum removal rate (98%). This photo-assisted Fenton degradation of Acid Orange 7 azo-dye molecules was exploiting HO center dot radicals from generated H2O2 and clay supported iron species, following the pseudo-first order kinetic mechanism. By using red mud pre-calcined at 400 degrees C, 10% improvement in overall discolouration was observed in comparison to the untreated clay. This improvement is attributed to the partial reduction of Fe3+ to Fe2+ species on the surface of the catalyst, and to the reaction with H2O2 to generate highly oxidative hydroxyl radicals. It was seen that the synergistic effect of photocatalysis due to the presence of TiO2 in the red mud also contributed in this photo Fenton process. Furthermore, the use of red mud/clay catalyst mixes assured 38% dye discolouration at pH 7, but a lowering of solution pH to 3 resulted in a much higher discolouration rate (over 80% after 1 h). The good fitting with a pseudo-second-order kinetic model (R-2 equals to 0.99) shows that adsorption processes could strongly contribute in the dye removal efficiency. (C) 2016 Elsevier B.V. All rights reserved.

In the nuclear field, the availability of effective techniques to eliminate lead pollution from wastewater is of interest both for the purposes of radiation protection from the radioactive isotope lead-210 and also for the issues related to the use of lead in the new generation reactors nowadays under study. Evidences exist of lead pollution due to the radioactive isotope lead-210 in the proximities of uranium extraction mines. In this study, two commercial granular activated carbons obtained by physical activation of coconut shell, specifically developed and selected to purify potable water from dissolved organics (GCN 1240) and for use in gold recovery systems (GCN 816 G), were studied in batch systems to evaluate their effectiveness for separation of lead (II) from aqueous solutions. A characterization of the two carbons, different in particle size, is provided through determination of their pHPZC and scanning electron microscope analysis. Adsorption of lead (II) was observed as a function of c...

Electrocoagulation is a group of various procedures used for removing contaminants from water by electrochemically dissolving aluminum or iron. The contaminants of the solution may be incorporated in the in situ forming metal hydroxide flocs, which can be filtered as a precipitate or skimmed as a float. The main features of the procedure are highlighted on the example of cleaning of an oily waste-water. Design parameters of a 1 m 3 /h waste-water cleaning system are calculated from the results of small-scale experiments.

The study aimed to evaluate the efficiency of dithiocarbamate functionalized silica coated magnetite nanoparticles (NPs) for Hg decontamination of saltwater either contaminated with Hg alone or with As and Cd. For this, the residual levels of Hg in seawater were assessed and Hg-contaminated or Hg+ As+ Cd-contaminated seawater toxicity to aquatic biota, before and after the sorption process, was compared. The results showed that under highly competitive conditions (water salts, Cd and As), the removal of Hg from seawater, by using these magnetic NPs, for the lowest concentration (50 mu g/L) was superior to 98% and for the highest concentration (500 mu g/L) ranged between 61% to 67%. Despite the great affinity of the magnetic NPs for Hg, they were not effective at removing As and Cd from seawater. In relation to the ecotoxicity endpoints after remediation, the mixture with lower Hg concentration exhibited no toxicity to rotifer Brachionus plicatilis and bacteria Vibrio fischeri; however, the mixture with higher concentration revealed toxicity. In addition, the toxicity of bacteria V. fischeri, rotifer B. plicatilis and algae Phaeodactylum tricornutum, whose responses where inhibited during its exposure to the non-remediate sample was considerably reduced after treatment with NPs. Furthermore, microalgae P. tricornutum appears to be most sensitive species while Artemia franciscana showed no toxic effects to the tested solutions. Both chemical and ecotoxicological approaches revealed a high efficiency for the remediation of Hg-contaminated saltwater. (C) 2016 Elsevier B.V. All rights reserved.

The efficiency of chitosan cross-linked with genipin (Chg) and cross-linked with genipin and grafted with caffeic acid (Ch(g+car)) to remove Hg(II) from waters was investigated. An optimal dose of 50 mg L-1 for both chitosan films was selected based on the equilibrium removal percentage and on the contact time required to attain the equilibrium. The sorption extent was dependent on the initial Hg(II) concentration (C-Hg,C-0), with removal efficiencies varying between 79% and 82% for C-Hg,C-0 = 0.05 mg L-1 and between 89% and 94% for C-Hg,C-0 = 0.50 mg L-1. Under ion competition, the Ch(g) and Ch(g+caf) films showed to be effective and selective for mercury in multimetallic solutions containing also cadmium and lead. In the case of natural river and seawaters, the mercury speciation played an important role in the overall sorption process, reducing the percentage removal of Hg. In terms of modeling, the kinetic data were well described by pseudo-first and pseudo-second order models, depending on the experimental conditions. The diffusion models suggested that the entire sorption process of Hg(II) by both Chg and Chg+caf films was essentially controlled by pore diffusion. The equilibrium data were well described by the Sips isotherm, and the estimated capacity was 2.2 and 4.0 mg g(-1) for Chg and Ch(g+caf) films, respectively. In the whole, the results showed that the sorption efficiency was improved by grafting caffeic acid to the polymeric chains of chitosan cross-linked with genipin. (C) 2016 Elsevier B.V. All rights reserved.

The effects of gold (ionic form and nanopartides - AuNPs) and pharmaceuticals (carbamazepine and fluoxetine) on enzymes involved in neurotransmission (acetylcholinesterase - AChE) and biotransformation (glutathione S-transferases - GST) were assessed by their incubation with Mytilus galloprovincialis' hemolymph and subcellular fraction of gills, respectively. AuNPs did not alter enzymatic activities unlike ionic gold that inhibited AChE and GST activities at 2.5 and 0.42 mg.L-1, respectively. Carbamazepine inhibited AChE activity at 500 mg.L-1 and fluoxetine at 1000 mg.L-1. GST was inhibited by carbamazepine at 250 mg.L-1 and by fluoxetine at 125 mg.L-1. Increased AChE activity was found in simultaneous exposures to fluoxetine and bovine serum albumin coated AuNPs (BSA-AuNPs). Concerning GST, in the simultaneous exposures, AuNPs revealed protective effects against carbamazepine (citrate and polyvinylpyrrolidone coated) and fluoxetine (citrate and BSA coated) induced inhibition. However, BSA-AuNPs increased the inhibition caused by carbamazepine. AuNPs demonstrated ability to interfere with other chemicals toxicity justifying further studies. (C) 2016 Elsevier Ltd. All rights reserved.

International audience; Contaminants in urban wet weather discharges originate from a number of sources such as materials from wet and dry atmospheric deposition, wastewaters, urban surface erosion, traffic-related activities, in-sewer deposits, etc. In the current study, four contributions (rainwater, dry atmospheric deposition, dry weather discharge and catchment surface + possible erosion of in-sewer deposits) to the total concentrations of priority substances have been assessed at the outlet of two urban catchments (one residential catchment with a combined system and one industrial area with a separate stormwater system) for 12 storm events (six for each catchment). Mass balances were calculated for seven metals and four pesticides, as well as for total suspended solids and chemical oxygen demand. The respective contributions of dry and wet atmospheric deposition, wastewater and catchment surface differ for each pollutant type, corresponding to different land use, activities, environments and sewer systems. For most of the pollutants, the catchment surface appears to be the main contribution, with significant storm event variability, excepted for atrazine in one catchment.

Metoprolol (MTP) is known as one of the most frequently detected beta blockers in surface waters, with potentially harmful impact on environment and human health due to its widespread use and resistance to hydrolysis. The removal of MTP in wastewater treatment plants is still very low due to fairly ineffective conventional water treatment procedures and, therefore, more efficient treatments are needed. To tackle this challenge, novel biosorbents composed of magnetite nanoparticles functionalized by kappa-carrageenan hybrid siliceous shells (Fe3O4@SiO2/SiCRG) were successfully prepared and tested in magnetically assisted removal of metoprolol tartrate from aqueous solutions. The MTP adsorption by the produced core-shell composite structures was thoroughly assessed and modeling of the equilibrium data was best fit with Langmuir and Toth models. The maximum observed MTP adsorption capacity of the magnetic hybrids amounted to 447 mg/g, thus representing an enhancement of 300% compared to most efficient MTP sorbents reported so far. The results of FTIR analysis indicate that the adsorption mechanism is mostly based on electrostatic interactions between sulfonate groups of kappa-carrageenan and protonated amine groups of metoprolol. The obtained Fe3O4@SiO2/SiCRG composite particles show a great potential for removing MTP from water, stemming from their high inherent absorption capacity and convenient magnetic separation. (C) 2016 Elsevier B.V. All rights reserved.

Forward osmosis (FO) is a promising membrane technology to combine seawater desalination and water reuse. More specifically, in a FO-reverse osmosis (RO) hybrid process, high quality water recovered from the wastewater stream is used to dilute seawater before RO treatment. As such, lower desalination energy needs and/or water augmentation can be obtained while delivering safe water for direct potable reuse thanks to the double dense membrane barrier protection. Typically, FO-RO hybrid can be a credible alternative to new desalination facilities or to implementation of stand-alone water reuse schemes. However, apart from the societal (public perception of water reuse for potable application) and water management challenges (proximity of wastewater and desalination plants), FO-RO hybrid has to overcome technical limitation such as low FO permeation flux to become economically attractive. Recent developments (i.e., improved FO membranes, use of pressure assisted osmosis, PAO) demonstrated significant improvement in water flux. However, flux improvement is associated with drawbacks, such as increased fouling behaviour, lower rejection of trace organic compounds (TrOCs) in PAO operation, and limitation in FO membrane mechanical resistance, which need to be better considered. To support successful implementation of FO-RO hybrid in the industry, further work is required regarding up-scaling to apprehend full-scale challenges in term of mass transfer limitation, pressure drop, fouling and cleaning strategies on a module scale. In addition, refined economics assessment is expected to integrate fouling and other maintenance costs/savings of the FO/PAO-RO hybrid systems, as well as cost savings from any treatment step avoided in the water recycling.

An adsorbent, SnO2 quantum dots (QDs) decorated reduced graphene oxide (RGO) nanocomposite, is used for removal of different organic dyes (methylene blue (MB), methyl orange (MO) and rhodamine B (RhB)), toxic metal ions (Co2+, Ni2+, Cu2+, Cd2+, Cr3+, Pb2+, Hg2+ and As3+), and pathogenic bacteria (Escherichia coli) from wastewater. It exhibits good removal capacity and fast adsorption rate for cationic dye MB. In binary solution the nanocomposite registered an excellent separation efficiency of 94% for MB/MO mixtures, whereas the same is 76% for MB/RhB mixture. The effect on removal process by different influencing parameters such as dosage of adsorbent (0.1-0.6 g/L), initial solution pH (3-11), initial dye concentration (10-50 ppm), contact time (0-60 min) and temperature (303-333 K) is investigated in order to find the optimum adsorption conditions. Adsorption isotherm data are extensively investigated using Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherms; it is found to fit well in Freundlich model. Adsorption kinetics is described by pseudo-second order kinetics. Thermodynamic study suggested that the MB adsorption on QDs-RGO is a spontaneous and exothermic process. QDs-RGO also shows good removal efficiency for lead (II) from individual as well as mixed solution. Adsorption kinetics and isotherm data are extensively investigated for adsorption of lead (II) and found to be better described by pseudo-second order kinetics and Freundlich model. Furthermore, QDs-RGO showed higher antibacterial activity towards E. coli than the individual constitute materials. It is essentially established from the results that QDs-RGO is an ideal aspirant for removal of positively charged organic dyes, toxic heavy metal ions and bacteria pathogen from wastewater. (C) 2016 Elsevier B.V. All rights reserved.

This work aimed to isolate and characterize organisms able to store polyhydroxyalkanoates (PHAs), from a mixed microbial culture (MMC) selected under feast and famine conditions, using hardwood sulfite spent liquor (HSSL), a by-product of the pulp and paper industry, as the carbon source. The MMC was able to accumulate PHA from the different HSSL carbon components (acetic acid, xylose and lignosulfonates) with a PHA storage content during the reactor operation of 54.2 +/- 10.6 % PHB. In order to clarify the MMC composition, isolation was performed from the MMC, using HSSL or its main components. Three isolates were identified: Rhodococcus spp., Pseudomonas spp. and Klebsiella spp. All isolates were able to grow and accumulate PHAs in harsh conditions of HSSL using xylose, the second most abundant sugar in nature. Rhodococcus and Pseudomonas isolates were able to accumulate a homopolymer PHB, whereas Klebsiella accumulated the copolymer P(HB-co-HV), with a composition of 96 % HB and 4 % HV. 16S rDNA clonal analysis was performed to identify the unculturable fraction of the MMC, and members of Novosphingobium spp., Sphingobium spp. and Pleomorphomonas spp., were found to be related to PHA production. The capability of the isolated bacteria to simultaneously consume xylose and accumulate PHAs offers a possibility for further studies and routes for the valorization of xylose-rich by-products.

It is demonstrated that colloidal magnetite nanoparticles can be used as nanosorbents for lanthanide ions dissolved in water. In particular, a series of experiments are performed for the removal of Eu(III) in distinct analytical conditions and by applying an external magnet to collect the sorbents previously dispersed in water samples. Furthermore, strategies for surface chemistry functionalization are also investigated, aiming to investigate the effect of this parameter on the removal capacity of the Fe3O4 nanoparticles. The supernatant solutions are monitored for the remaining amount of Eu(III) by fluorescence emission measurements in the presence of 2,6-pyridinedicarboxylic acid as a sensitizer. The results demonstrate that neat Fe3O4 nanoparticles are capable of capturing lanthanide ions (III) from aqueous solutions (pH 7), without need of surface modification, and for subsequent removal by magnetic separation. During the removal, efficiency is increased after modifying the particles' surfaces with silica and 3-aminopropyltrimethoxysilane; in alkaline medium (pH 10), there is complete removal regardless the type of nanosorbent used. This has been explained by the formation of insoluble Eu(III) species that adsorb strongly to the nanosorbents surfaces allowing their subsequent magnetic separation.

There have been extensive and comprehensive reviews in the field of metal sulfide precipitation in the context of environmental remediation. However, these works have focused mainly on the removal of metals from aqueous solutions-usually, metal-contaminated effluents-with less emphasis on the precipitation process and on the end-products, frequently centering on metal removal efficiencies. Recently, there has been an increasing interest not only in the possible beneficial effects of these bioremediation strategies for metal-rich effluents but also on the formed precipitates. These metal sulfide materials are of special relevance in industry, due to their optical, electronic, and mechanical properties. Hence, identifying new routes for synthesizing these materials, as well as developing methodologies allowing for the control of the shape and size of particulates, is of environmental, economic, and practical importance. Multiple studies have shown proof-of-concept for the biological synthesis of inorganic metallic sulfide nanoparticles (NPs), resorting to varied organisms or cell components, though this information has scarcely been structured and compiled in a systematic manner. In this review, we overview the biological synthesis methodologies of nanosized metal sulfides and the advantages of these strategies when compared to more conventional chemical routes. Furthermore, we highlight the possibility of the use of numerous organisms for the synthesis of different metal sulfide NPs, with emphasis on sulfate-reducing bacteria (SRB). Finally, we put in perspective the potential of these methodologies in the emerging research areas of biohydrometallurgy and nanobiotechnology for the uptake of metals in the form of metal sulfide nanoparticles. A more complete understanding of the principles underlying the (bio)chemistry of formation of solids in these conditions may lead to the large-scale production of such metal sulfides, while simultaneously allowing an enhanced control over the size and shape of these biogenic nanomaterials. POCI-01-0145-FEDER-007679

International audience; Recently, environmental scientists have been focused their attention on the occurrence and the elimination of specific organic compounds in water. Among them, chlorophenols are considered to be a public health problem due to their carcinogenic properties. Thus, there is an important need to find new strategies to efficiently transform these compounds to no toxic or inactive by-products. In this work the photocatalytic removal of 2,4-dichlorophenol in water solution was investigated at laboratory scale in a batch photoreactor using a commercial titanium dioxide as catalyst. Effects of different operating parameters such as initial pollutant concentration, catalyst load and UV-light intensities on the photocatalytic elimination efficiency were evaluated in detail for future practical application purposes. Obtained data clearly showed an optimum degradation of the target compound under an initial pollutant concentration of 1.5 mg/L, a titanium dioxide concentration of 1 g/L and for UV-light intensity of 59.6 W/m(2). The total organic carbon removal was also calculated in order to confirm the mineralization of 2,4-dichlorophenol. The obtained data showed a higher mineralization yield under the optimized photocatalytic reaction conditions demonstrating the performance of the photocatalytic oxidation to remove the target molecule at low concentrations from aqueous medium.

This paper presents the development and application of a new multi-residue analytical method providing the first data on the environmental occurrence of human pharmaceuticals in Africa, particularly the Nairobi River basin (Kenya).Based on pharmaceutical consumption data available for the Nairobi region, 43 'priority' pharmaceutically active ingredients (PAIs) were selected for this study. On the basis of magnetic sector high-resolution mass spectrometry, a new methodology involving both full-scan screening and selective target analysis has been developed to investigate the presence of the defined priority PAIs. Subsequent analysis of the corresponding standard compounds provided the full confirmation and indicative concentrations (low ng/L-high mu g/L) of 10 human PAIs in the Nairobi River. The detected compounds belong to different classes, i.e. antibiotics, analgesic/anti-inflammatory and anti-epileptic drugs, antimalarials and antiretrovirals. Ibuprofen, paracetamol, sulfamethoxazole and zidovudine showed to be the most concentrated PAIs (about 10-30 mu g/L). The concentration of the antiretrovirals (lamivudine, zidovudine and nevirapine) is clearly higher than those reported in the literature, although environmental data on this class of PAIs are still very limited. To the best of our knowledge, this is the first study that provides evidence of detection of lamivudine in surface water. The presented unique data on the occurrence of selected PAIs in the aquatic environment of Africa clearly show that the high prevalence of specific diseases like HIV/AIDS infection in developing countries might result in a different pattern of PAIs in environmental waters compared to the more developed regions. (C) 2012 Elsevier B.V. All rights reserved.

Across West Bengal and Bangladesh, concentrations of Cl in much groundwater exceed the natural, upper limit of 10 mg/L. The Cl/Br mass ratios in groundwaters range up to 2500 and scatter along mixing lines between waste-water and dilute groundwater, with many falling near the mean end-member value for waste-water of 1561 at 126 mg/L Cl. Values of Cl/Br exceed the seawater ratio of 288 in uncommon NO(3)-bearing groundwaters, and in those containing measurable amounts of salt-corrected SO(4) (SO(4) corrected for marine salt). The data show that shallow groundwater tapped by tube-wells in the Bengal Basin has been widely contaminated by waste-water derived from pit latrines, septic tanks, and other methods of sanitary disposal, although reducing conditions in the aquifers have removed most evidence of NO(3) additions from these sources, and much evidence of their additions of SO(4). In groundwaters from wells in palaeo-channel settings, end-member modelling shows that >25% of wells yield water that comprises ≥10% of waste-water. In palaeo-interfluvial settings, only wells at the margins of the palaeo-interfluvial sequence contain detectable waste water. Settings are identifiable by well-colour survey, owner information, water composition, and drilling. Values of Cl/Br and faecal coliform counts are both inversely related to concentrations of pollutant As in groundwater, suggesting that waste-water contributions to groundwater in the near-field of septic-tanks and pit-latrines (within 30 m) suppress the mechanism of As-pollution and lessen the prevalence and severity of As pollution. In the far-field of such sources, organic matter in waste-water may increase groundwater pollution by As.

Despite many advantages of anaerobic sewage treatment over conventional activated sludge treatment, it has not yet been applied in temperate zones. This is especially because effluent from low-temperature anaerobic treatment contains nitrogen and dissolved methane. The presence of nitrogen and methane offers the opportunity to develop a reactor in which methane is used as electron donor for denitrification. Such a reactor could be used in a new concept for low-temperature anaerobic sewage treatment, consisting of a UASB-digester system, a reactor for denitrification coupled to anaerobic methane oxidation, and a nitritation reactor. In the present study denitrifying methanotrophic bacteria similar to 'Candidatus Methylomirabilis oxyfera' were enriched. Maximum volumetric nitrite consumption rates were 33.5 mg NO(2)(-)-N/Ld (using synthetic medium) and 37.8 mg NO(2)(-)-N/Ld (using medium containing effluent from a sewage treatment plant), which are similar to the maximum rate reported so far. Though the goal was to increase the rates, in both reactors, after reaching these maximum rates, volumetric nitrite consumption rates decreased in time. Results indicate biomass washout may have significantly decelerated enrichment. Therefore, to obtain higher volumetric consumption rates, further research should focus on systems with complete biomass retention.

International audience; The formation of several by-products from the photodegradation of testosterone was previously observed under laboratory conditions. The objectives of the manuscript were to complete the identification of testosterone's photoproducts and to develop an analytical method for the detection of testosterone as well as its three main photoproducts in natural sunlit surface waters. To accomplish these tasks, an efficient extraction method was developed based on solid-phase extraction, followed by the use of liquid chromatography coupled to tandem mass spectrometry, a selective and sensitive detection method. This analytical procedure has the capability of detecting target analytes in the ng/L range, with recoveries above 80 %. The methodology was successfully applied to the analysis of testosterone and its photoproducts in several surface waters.

An important issue in chlorine drinking water disinfection is the generation from natural organic matter (NOM) of disinfection by-products (DBPs), especially trihalomethanes (THMs). The THMs generation can be limited by reducing the levels of NOM prior to the chlorination step. Herein, photo-Fenton system under solar simulator degraded humic acid solutions (as NOM model compounds), as well as NOM contained in river water (Pance River, Cali-Colombia), and dramatically reduced THMs formation during the subsequent chlorination step. In both cases the initial pH of treated water was near to 7.In no pre-treated river water 100-160 mu g/L of THMs are formed during chlorination while values of 20-60 mu g/L were reached in water previously treated for 4 h by neutral photo-Fenton under solar simulator. The decrease in the generated THMs/total organic carbon ratio suggests that mainly the NOM fraction sensitive to THMs formation was photo-degraded. Therefore, the neutral photo-Fenton reagent could be implemented as a technological option for NOM removal for limiting THMs formation during a subsequent chlorination step. (C) 2011 Elsevier B.V. All rights reserved.

Iodinated contrast media (ICM) are persistent and ubiquitous water pollutants. Because of their high water solubility and biochemical stability, their phase-separation and recovery from the aquatic environment is very difficult. Here, borate was chosen as a complexing agent of the two diagnostic aids iomeprol and iopamidol in order to provide them with a negative charge and to fix the resulting adducts on Dowex 1X4 ion exchangers. A systematic characterization study of the complex by means of capillary zone electrophoresis and 11B NMR revealed that iomeprol and iopamidol interact with borate anions in aqueous solutions giving a 1:1 single-charged adduct and that the association constant at 25 °C for both contrast agents is highest at pH 10.5. These findings allowed the proper calibration of experimental parameters for further batch adsorption–desorption trials, where the two ICM were shown to be almost completely removed from the water phase and released from the solid sorbents in mild conditions, enabling the recovery of functional resin.

In this study, advanced oxidation technologies, namely Fenton Process (FP), Fenton-Like Process (FLP), ozonation (O-3) and O-3/H2O2 processes, were applied to synthetic wastewater containing 3-indolebutyric acid (IBA). The effectiveness of each process was investigated at different pH values, Fe+2, Fe+3, O-3 and H2O2 concentrations with respect to the removal efficiencies for chemical oxygen demand (COD) and total organic carbon (TOC). The best removal efficiencies were seen at pH 3 and 2 mM Fe concentration in both FP and FLP, in which the optimum H2O2 concentrations were 6 mM for FP and 10 mM for FLP. Optimum process conditions were pH 12 for the O-3 process, pH 9 for the O-3/H2O2 process and 1:1 O-3/H2O2 molar ratio. The highest COD removal efficiency was 86 percent, obtained in the O-3/H2O2 process and the highest TOC removal efficiency was obtained at 77 percent in the FP. Water Environ. Res., 84, 100 (2012).

Lack of focus on the treatment of wastewaters bearing potentially hazardous pollutants like 1,1,2 trichloroethane and 1,1,2,2 tetrachloroethane in anaerobic reactors has provided an impetus to undertake this study. The objective of this exercise was to quantify the behavior of upflow anaerobic sludge blanket reactors and predict their performance based on the overall organic substrate removal. The reactors (wastewater-bearing TCA (R2), and wastewater-bearing TeCA (R3)) were operated at different hydraulic retention times (HRTs), i.e., 36, 30, 24, 18, and 12 h corresponding to food-to-mass ratios varying in the range of 0.2–0.7 mg chemical oxygen demand (COD) mg−1 volatile suspended solids day−1. The process kinetics of substrate utilization was evaluated on the basis of experimental results, by applying three mathematical models namely first order, Grau second order, and Michaelis-Menten type kinetics. The results showed that the lowering of HRT below 24 h resulted in reduced COD removal efficiencies and higher effluent pollutant concentrations in the reactors. The Grau second-order model was successfully applied to obtain the substrate utilization kinetics with high value of R 2 (>0.95). The Grau second-order substrate removal constant (K 2) was calculated as 1.12 and 7.53 day−1 for reactors R2 and R3, respectively. This study demonstrated the suitability of Grau second-order kinetic model over other models, for predicting the performance of reactors R2 and R3, in treating wastewaters containing chlorinated ethanes under different organic and hydraulic loading conditions.

Now that more than half of the world's population lives in cities, improving urban resource cycles is crucial for sustainable urban development. Currently cities are highly dependent on external supplies of water, energy, nutrients, and other materials, while local possibilities of self-production of such resources are generally overlooked. This article describes a novel method, the urban harvest approach (UHA), its rationale, and the steps toward sustainable urban resource planning. The UHA is based on the urban metabolism concept. Herein, a city is regarded to have multiple potentials in the form of untapped primary and secondary (already used) resources that can be utilized. The UHA works on the principle that urban systems and their direct peri-urban surroundings can become self-sufficient by applying three strategies: minimizing demand, minimizing outputs, and multisourcing. An elaboration of the UHA for the resource “water” at the building scale is also presented in this article. A freestanding house in the Netherlands and a similar house in Australia were studied, with a focus on indoor consumption. Results showed a 40% demand reduction when water-saving technologies were implemented. In both cases, after demand minimization, local resources were sufficient to cover the demand by recycling grey water and harvesting rainwater. These findings confirm that a multimeasure implementation according to the three different strategies is needed to achieve sustainable urban water systems. The UHA helps to structure large influences of urban context on water and other resource cycles as an aid to urban planners and water managers in designing sustainable urban areas.

Coastal and freshwater eutrophication continues to accelerate at sites around the world despite intense efforts to control agricultural P loss using traditional conservation and nutrient management strategies. To achieve required reductions in nonpoint P over the next decade, new tools will be needed to address P transfers from soils and applied P sources. Innovative remediation practices are being developed to remove nonpoint P sources from surface water and groundwater using P sorbing materials (PSMs) derived from natural, synthetic, and industrial sources. A wide array of technologies has been conceived, ranging from amendments that immobilize P in soils and manures to filters that remove P from agricultural drainage waters. This collection of papers summarizes theoretical modeling, laboratory, field, and economic assessments of P removal technologies. Modeling and laboratory studies demonstrate the importance of evaluating P removal technologies under controlled conditions before field deployment, and field studies highlight several challenges to P removal that may be unanticipated in the laboratory, including limited P retention by filters during storms, as well as clogging of filters due to sedimentation. Despite the potential of P removal technologies to improve water quality, gaps in our knowledge remain, and additional studies are needed to characterize the long-term performance of these technologies, as well as to more fully understand their costs and benefits in the context of whole-farm- and watershed-scale P management.