Dairy soiled water (DSW) is water from concreted areas, hard stand areas and holding areas for livestock that has become contaminated by livestock faeces or urine, chemical fertilisers and parlour washings. Losses of DSW occur as point (e.g. storage, pivot irrigators) and diffuse losses (e.g. during or shortly after land application). The concept of a permeable reactive interceptor (PRI), comprising a denitrifying bioreactor woodchip cell to convert nitrate (NO₃⁻) to dinitrogen (N₂) gas and an adsorptive media cell for phosphorus (P) and ammonium (NH₄⁺) mitigation, attempts to simultaneously treat mixed pollutants. This study is the first attempt to test this concept at laboratory-scale. Washing of woodchip media prior to PRI operation produced low NO₃⁻but high NH₄⁺, dissolved reactive P (DRP) and dissolved organic carbon losses. Dairy soiled water was then treated in replicated PRIs containing woodchip in combination with zeolite or gravel compartments. In general, all PRIs were highly efficient at reducing NO₃⁻, NH₄⁺, DRP, dissolved unreactive phosphorus (DUP) and dissolved organic nitrogen (DON) from an influent water replicating DSW. Longitudinal and hydrochemical PRI profiles, as well as zeolite batch experiments, showed that woodchip can both enhance NO₃⁻reduction and adsorb nutrients. Since woodchip is likely to become saturated, it is important to place the reactive media cell further into the sequence of treatment. Even though the majority of the dissolved nutrients were mitigated, the PRIs also emitted greenhouse gases, which would need further remediation sequences.

This paper examined the gut digestive enzymes, trypsin and leucine aminopeptidase (LAP), in gypsy moth (Lymantria dispar, L.) larvae exposed to cadmium. We analyzed the 3-day acute effect, chronic effects from hatching until sacrifice, and recovery from long-term dietary treatment with cadmium concentrations of 10 and 30 μg Cd/g dry food. The activities of both examined enzymes declined at the higher level of cadmium after both acute and chronic treatments and did not recover within 3 days of feeding a diet with no added cadmium. Leucine aminopeptidase was more sensitive because its activity was inhibited after both short-term treatments. Three trypsin and one leucine aminopeptidase isoform were detected by electrophoresis. Egg hatches (full-sib families) differed in enzyme activities, index of phenotypic plasticity, and isozyme expression after different treatments. Statistically significant positive correlations between these enzymes pointed to common genetic regulation. Moreover, variances were higher for the control group than for cadmium treatment groups implying that these proteolytic enzymes did not participate directly in detoxification. These results suggest that, with additional research to discover the mechanisms of enzyme inhibition, trypsin and leucine aminopeptidase might be used as biomarkers to indicate the severity of gastrointestinal disease due to cadmium intake.

The processing, storage, and flux of inorganic carbon in rivers and streams play an influential role in the lateral transfer of atmospheric and terrestrial carbon to the marine environment. Quantifying and understanding this transfer requires a rapid and accurate means of measuring representative concentrations of dissolved inorganic carbon (DIC) and CO₂in field settings. This paper describes a field method for the determination of DIC based on the direct measurement of dissolved CO₂using a commercial carbonation meter. A 100-mL water sample is combined with 10 mL of a high ionic strength, low-pH, citrate buffer, mixed well, and the dissolved CO₂concentration is measured directly. The DIC is then calculated based on the dissolved CO₂concentration, buffer-controlled ionic strength, pH, and temperature of the mixture. The method was accurate, precise, and comparable to standard laboratory analytical methods when tested using prepared sodium bicarbonate solutions up to 40 mM DIC, North Atlantic seawater, commercial bottled waters, and carbonate spring waters. Coal mine drainage waters were also tested and often contained higher DIC concentrations in the field than in subsequent laboratory measurements; the greatest discrepancy was for the high-CO₂samples, suggesting that degassing occurred after sample collection. For chemically unstable waters and low-pH waters, such as those from high-CO₂mine waters, the proposed field DIC method may enable the collection of DIC data that are more representative of natural settings.

Extractions with mixtures of oxalic acid, ammonium oxalate, and ascorbic acid have been used to analyze trace metals that are occluded in Fe and Mn oxides in soil samples. In our experiments, the amount of Fe extracted from two Andisols decreased with increased extraction time using a mixture of 0.1 mol L⁻¹oxalic acid, 0.175 mol L⁻¹ammonium oxalate, and 0.19 mol L⁻¹ascorbic acid (OxAsc). Differential X-ray diffraction analysis showed the presence of Fe(II)C₂O₄ · 2H₂O in the residue after the extraction, and the amount of this precipitate increased with extraction time. These results indicate that the decrease in Fe extraction with time was caused by precipitation of Fe(II)C₂O₄ · 2H₂O. The amounts of some trace metals (Cd, Co, Mn, Ni, and Zn) extracted with OxAsc showed trends similar to that of Fe, whereas As, Cu, and Pb did not show this trend. A coprecipitation experiment showed that the concentrations of Cd, Co, Mn, Ni, and Zn markedly decreased after the precipitation of Fe(II)C₂O₄ · 2H₂O, whereas those of As, Cu, and Pb did not noticeably change. These results indicate that some trace metals coprecipitated with Fe(II)C₂O₄ · 2H₂O during extraction with OxAsc. This coprecipitation results in underestimation of oxide-occluded trace metals in soils; therefore, using mixtures of oxalic acid, ammonium oxalate, and ascorbic acid to extract some trace metals occluded in Fe and Mn oxides may yield erroneous data.

The feasibility of cyanobacteria removal from freshwater by a dielectric barrier discharge (DBD) process is investigated. Seven commercial and environmental cyanobacteria strains, as well as real algae-laden water, were tested. The removal of the cyanobacteria was evaluated by analyzing the changes in chlorophyll a content, total organic carbon (TOC) concentration, and cell morphology. Nearly total removal of chlorophyll a was achieved within 20 min, while the TOC analysis exhibited an increase-decrease-increase trend in 60 min of treatment, likely due to the oxidation of intracellular and intercellular materials. Observation under light microscopy revealed the disruption of intracellular and intercellular structures within 5 min of DBD treatment and thus supported the TOC analysis. Increasing the salinity of the medium from 0 to 5 parts per thousand (ppt) improved treatment efficiency, where similar level of chlorophyll a removal (around 93 %) was achieved in only half the treatment time. Application of DBD on real algae-laden water from a fish farm yielded higher treatment efficiency than in synthetic medium, indicating the promising application of DBD as a means to control cyanobacteria bloom in fresh and estuary water bodies.

Copper hydrotalcites with and without adsorbed chlorophyllin exhibit a bactericidal effect that depends on the copper release and the basicity, which can be tuned through the chlorophyllin adsorption. The prepared solids performed well for the elimination of Escherichia coli, Enterobacter aerogenes, Salmonella enterica, and Staphylococcus aureus bacteria. The results showed that the copper-containing hydrotalcite with the adsorbed chlorophyllin is the most active material. Wastewaters from a metal industry were treated with these hybrid compounds, and the bactericidal effect was comparable with the results reported using more complex methods such as photocatalysis. Furthermore, one main advantage of these hybrid compounds is its low human toxicity compared with silver-containing materials.

This work is a synthesis of a 5-year estimation of nitrogen balance at a semi-arid, semi-natural, undisturbed grassland site (Bugac). We measured the N input of atmospheric pollutants by wet and dry deposition of gases and aerosols, while we considered N output as NO and N₂O gases volatilized from soil. Besides measurements of soil fluxes, the denitrification-decomposition (DNDC) ecological model was also used and simulations were compared to and validated against the measured values. The daily flux simulations generally did not match well the measured data for N₂O and NO. In most cases, the mean fluxes were underestimated, though results of the comparison of monthly values suggest that model data, together with observed deposition data, are applicable to estimate the net N balance for grasslands. The calculated yearly N balance (net flux) between atmosphere and surface, without biological fixation and effect of grazing, ranged between −9.4 and −14 kg N ha⁻¹ year⁻¹as the sum of the measured deposition and emission terms, −11 to −15 and 0.9 to 2.9 kg N ha⁻¹ year⁻¹, respectively, between 2006 and 2010. Observed and modeled soil emissions were lower by one order of magnitude than atmospheric deposition. Considering the biological nitrogen fixation and the effect of grazing (effects of both grazed plant and excreta), the net nitrogen balance varies within −6.6 and −11 kg N ha⁻¹ year⁻¹. It seems — taking into account the high uncertainty in calculation due to the effect of grazing — that sources of nitrogen exceed the sinks; the surplus is probably mineralized in the soil.

Methane production by methanogenic microbes under anaerobic condition is affected by the types of fertilizers, which determine carbon availability, used in rice fields. In addition, irrigation management controls oxygen availability in soil. Thus, irrigation management and types of fertilizers are major driving forces for methane emission in rice fields. While these factors affect paddy microbial communities over the course of cultivation, little is known about the effects of fertilizers and irrigation conditions on initial paddy microbial communities. In this study, we investigated the initial impacts of fertilizers and irrigation systems on paddy microbial communities and methane emission. At early stages of rice cultivation (2 weeks after transplanting 15-day-old rice seedlings), a high amount of methane was emitted from rice fertilized with swine manure. In addition, pre-transplantation flooding increased methane emission by 30 %. Although these conditions did not affect the overall paddy soil microbial communities, 126 operational taxonomic units (OTUs) were found to be significantly more abundant in paddy soils fertilized with swine manure. These OTUs included archaeal methanogenic species and bacterial substrate providers for biomethane production. Shared-OTU analysis with swine fecal microbial communities indicated swine manure as the origin of key methane-producing microbes. In conclusion, the applications of swine manure and permanent flooding irrigation introduce active methane producers and enhance methane emission, respectively, and should therefore be avoided.

The aim of this work is to increase the information on trace metals in seabirds and coastal soils in the Antarctica. Concentrations (mg kg⁻¹dry weight) of Cd, Cu, Cr, Ni, Mn, Zn and Pb were determined by ICP-MS in fresh excreta and feathers of Gentoo penguins as well as in soils around the nesting sites where this species inhabits. Samples were collected in four locations throughout the Antarctic Peninsula (January 2014): O’Higgins Base, Stranger Point, Neko Harbor and Doumer Island. The highest levels of elements were found in excreta from O’Higgins Base (2.92, 266.83, 2.99, 44.75, 18.15, 1.68 and 317.92 for Cd, Cu, Cr, Mn, Ni, Pb and Zn, respectively) and Stranger Point (1.97, 222.51, 2.98, 36.62, 13.41, 1.46 and 201.18 for Cd, Cu, Cr, Mn, Ni, Pb and Zn, respectively. Similarly, the highest levels were found in feathers from O’Higgins Base (0.21, 20.89, 1.44, 1.19, 5.90, 0.63 and 64.07 for Cd, Cu, Cr, Mn, Ni, Pb and Zn, respectively) and Stranger Point (0.14, 19.65, 1.47, 1.23, 3.85, 0.60 and 64.19 for Cd, Cu, Cr, Mn, Ni, Pb and Zn, respectively). In soils, the highest levels were found in O’Higgins Base (4.31, 421.94, 64.75, 404.76, 28.13, 281.54 and 484.99 for Cd, Cu, Cr, Mn, Ni, Pb and Zn, respectively), whereas the lowest levels were found in Neko Harbor and Doumer Island. These results observed could be related to the major human presence in the northern area of the Antarctic Peninsula and large-scale transport of pollutants. The metals detected in the excreta of the Gentoo penguin can contribute to increase the contamination of coastal terrestrial ecosystems, which could also affect other living organisms.

Degradation and fate of sulfamethazine (SMZ) were determined under aerobic and anaerobic conditions in soil with and without swine manure amendment. For both aerobic and anaerobic conditions, SMZ disappeared rapidly during the first 7 days followed by slow disappearance which may indicate that SMZ had become more persistent and less available. For soils receiving 100 mg/kg of SMZ, the percent of SMZ remaining in the soil after 63 days were between 25 and 60 %. Depending on the initial SMZ concentration, estimated half-lives for aerobic and anaerobic incubations ranged from 1.2 to 6.6 and 2.3 days to more than 63 days, respectively. Addition of manure (0.054 g/g soil) did not significantly affect the half-lives of SMZ. Inhibitory effects of SMZ on anaerobic microbial respiration were observed in unamended soil at concentrations of 50 mg/kg or higher, but only transient inhibitory effects were found in aerobic soil. Five to 22 % of the¹⁴C[phenyl]-SMZ added were extracted at the end of the incubations while 70 to 91 % of the¹⁴C were converted to bound (non-extractable) forms in both manure amended and unamended soil. Only 0.1 to 1.5 % of¹⁴C-SMZ was mineralized to¹⁴CO₂. Disappearance of SMZ in sterilized soil was not completely halted indicating possible contribution of abiotic processes to the disappearance of SMZ in soil.