Over the past few years the number of biogas slurries, which are generally used as nitrogen fertilisers, have seen a steady increase in Germany. A mechanistic ammonia volatilisation model was developed to predict the ammonia losses of these slurries when applied to bare soil, maize, wheat and rye grass canopies. Data for model development were collected from several field measurements carried out at two locations in Northern Germany between the years of 2007 and 2008. Additionally, the behaviour of the slurries on and in the soil was investigated through the use of infiltration pot experiments. The model includes three main compartments: slurry, atmosphere and soil. The soil compartment model is relatively simple, as the slurry infiltration, nitrification and ploughing dislocation into the soil determined in the experiments showed quantitatively no significant differences between the tested slurries (mono-fermented, co-fermented and pig slurry) and soils (sand soil and loamy sand). Hence, instead of a complex soil model, stable reduction factors, as derived from the experiments, were implemented in the model. Simulated ammonia emissions were statistically compared (root mean square error (RMSE), modelling efficiency (ME), linear regression) to the observed emissions. All evaluations showed an acceptable model performance (RMSE = 1.80 kg N ha−1), although there were a few number of anomalies which could not be modelled in an adequate way. A model sensitivity analysis showed that temperature and slurry pH value are the main drivers of NH3 volatilization in the model. Following a change of +1°C or of +0.1 pH unit ammonia volatilization will increase by about 1% and 1.6% of the applied total ammoniacal nitrogen, respectively. We were able to show that a simple model approach could explain most factors of ammonia volatilization in biogas crop rotations.

Water quality of Lake Okeechobee has been a major environmental concern for many years. Transport of dissolved organic matter (DOM) in runoff water from watershed is critical to the increased inputs of nutrients (N and P) and metals (Cu and Zn). In this study, 124 soil samples were collected with varying soil types, land uses, and soil depths in Lake Okeechobee watershed and analyzed for water-extractable C, N, P, and metals to examine the relationship between dissolved organic carbon (DOC) and water soluble nutrients (N and P) and metals in the soils. DOC in the soils was in 27.64–400 mg kg⁻¹ (69.30 mg kg⁻¹ in average) and varied with soil types, land uses, and soil depth. The highest water-extractable DOC was found in soils collected in sugar cane and field crops (277 and 244 mg kg⁻¹ in average, respectively). Water soluble concentrations of N and P were in the range of 6.46–129 and 0.02–60.79 mg kg⁻¹, respectively. The ratios of water-extractable C/N and C/P in soils were in 0.68–12.52 (3.23 in average) and 3.19–2,329 (216 in average), and varied with land uses. The lowest water-extractable C/N was observed in the soils from dairy (1.66), resident (1.79), and coniferous forest (4.49), whereas the lowest water-extractable C/P was with the land uses of dairy (13.1) and citrus (33.7). Therefore, N and P in the soils under these land uses may have high availability and leaching potential. The concentrations of water soluble Co, Cr, Cu, Ni, and Zn were in the ranges of < method detection limit (MDL)–0.33, <MDL–0.53, 0.04–2.42, <MDL–0.71, and 0.09–1.13 mg kg⁻¹, with corresponding mean values of 0.02, 0.01, 0.50, 0.07, and 0.37 mg kg⁻¹, respectively. The highest water soluble Co (0.10 mg kg⁻¹), Cr (0.26 mg kg⁻¹), Ni (0.31 mg kg⁻¹), and Zn (0.80 mg kg⁻¹) were observed in soils under the land use of sugar cane, whereas the highest Cu (1.50 mg kg⁻¹) was with field crop. The concentration of DOC was positively correlated with total organic carbon (TOC) (P <0.01), water soluble N (P <0.01), electrical conductivity (EC, P <0.01), and water soluble Co, Cr, Ni, and Zn (P <0.01), and Cu (P <0.05), whereas water soluble N was positively correlated with water soluble P, Cu, and Zn (P <0.01) in soils. These results indicate that the transport of DOC from land to water bodies may correlate with the loss of macro-nutrients (N, P), micro-nutrients (Cu, Zn, and Ni), and contaminants (Cr and Co) as well.

There are several possible methods by which amine groups can be grafted on the surface of activated carbon (AC) to improve their capacity for CO2 adsorption. Ethylenediamine and diethylenetriamine were selected as amino compounds for anchoring on the surface of an oxidized AC. Oxidation of AC was carried out by concentrated nitric acid. For each amino compound, two “in-solvent” and “solvent-free” methods with a number of grafting times were studied. Nitrogen adsorption–desorption at 77 K and proximate and ultimate analysis were used to determine physical and chemical characteristics of the samples. Temperature-programmed (TP) CO2 adsorption test from 30°C to 120°C were performed to investigate the effect of modification on CO2 capture. The modification clearly had a negative effect on the textural characteristics of the samples, so the samples showed a less CO2 uptake at lower temperatures. However, the decrease of capture capacity with increasing temperature is to somewhat softer for amine-grafted samples, so that they have a capacity comparable to the parent sample or even more than that at elevated temperatures. This property may give the new adsorbents this opportunity to be used at flue gas temperature with a higher efficiency. CO2 capture capacity per unit surface area of all the amine-modified samples, however, was significantly improved, compared to the parent sample presenting a great influence of amino groups on the CO2 capture capacity. Moreover, the used amine compounds and grafting methods were compared in terms of adsorbent characteristics and CO2 uptake curves. Cyclic adsorption–desorption tests showed a satisfactory regeneration for the modified samples.

We investigated the influence of cadmium stress on zinc hyperaccumulation, mineral nutrient uptake, and the content of metal-binding proteins in Arabidopsis halleri. The experiments were carried out using plants subjected to long-term cadmium exposure (40 days) in the concentrations of 45 and 225 μM Cd²⁺. Inductively coupled plasma-mass spectrometry, size exclusion chromatography coupled with plasma-mass spectrometry, and laser ablation inductively coupled plasma-mass spectrometry used for ablation of polyacylamide gels were employed to assess the content of investigated elements in plants as well as to identify metal-binding proteins. We found that A. halleri is able to translocate cadmium to the aerial parts in high amounts (translocation index >1). We showed that Zn content in plants decreased significantly with the increase of cadmium content in the growth medium. Different positive and negative correlations between Cd content and mineral nutrients were evidenced by our study. We identified more than ten low-molecular-weight (<100 kDa) Cd-binding proteins in Cd-treated plants. These proteins are unlikely to be phytochelatins or metallothioneins. We hypothesize that low-molecular-weight Cd-binding proteins can be involved in cadmium resistance in A. halleri.

Characterization of spatial variation of heavy metals in urban soils is essential to identify pollution sources and potential risks to humans and the environment. While heavy metals concentration in soils depends also on the nature of bedrock and on abiotic and biotic factors, it can be argued that nowadays, due to increasing human activities, it is determined mainly by anthropogenic sources. We determined concentrations and spatial distribution of heavy metals, with particular focus on those potentially toxic (As, Cr, Pb, V, and Zn), in urban and peri-urban soils of Cosenza-Rende (southern Italy). One hundred forty-nine samples of topsoil (0–10 cm) were collected and analyzed for 36 elements by X-ray fluorescence spectrometry and inductively coupled plasma mass spectrometry (ICP-MS). In addition, 18 samples of rocks were collected on outcrops of whole area and analyzed by ICP-ES and ICP-MS. Geostatistical methods were used to map the concentrations of major oxides and several minor elements. Heavy metals in the analyzed samples showed a wide range of concentrations, primarily controlled by the geochemical composition of bedrock, with the notable exceptions of Cu, Pb, and Zn, whose concentrations are heavily affected by land use and anthropogenic pollution in urban areas. Geochemical analysis and spatial distribution showed that high concentrations of potentially toxic elements are found in soils near major roads, indicating that anthropogenic factors determine the anomalies in these areas.

To elucidate the influence of airborne materials on the ecosystem of Japan’s Yakushima Island, we determined the elemental compositions and Sr and Nd isotope ratios in streamwater, soils, vegetation, and rocks. Streamwater had high Na and Cl contents, low Ca and HCO₃ contents, and Na/Cl and Mg/Cl ratios close to those of seawater, but it had low pH (5.4 to 7.1), a higher Ca/Cl ratio than seawater, and distinct ⁸⁷Sr/⁸⁶Sr ratios that depended on the bedrock type. The proportions of rain-derived cations in streamwater, estimated by assuming that Cl was derived from sea salt aerosols, averaged 81 % for Na, 83 % for Mg, 36 % for K, 32 % for Ca, and 33 % for Sr. The Sr value was comparable to the 28 % estimated by comparing Sr isotope ratios between rain and granite bedrock. The soils are depleted in Ca, Na, P, and Sr compared with the parent materials. At Yotsuse in the northwestern side, plants and the soil pool have ⁸⁷Sr/⁸⁶Sr ratios similar to that of rainwater with a high sea salt component. In contrast, the Sr and Nd isotope ratios of soil minerals in the A and B horizons approach those of silicate minerals in northern China’s loess soils. The soil Ca and P depletion results largely from chemical weathering of plagioclase and of small amounts of apatite and calcite in granitic rocks. This suggests that Yakushima’s ecosystem is affected by large amounts of acidic precipitation with a high sea salt component, which leaches Ca and its proxy (Sr) from bedrock into streams, and by Asian dust-derived apatite, which is an important source of P in base cation-depleted soils.

In Southern Spain, as in other semi-arid zones, plants used for the phytoremediation of heavy metal-contaminated sites must be able to withstand not only the challenging soil conditions but also seasonal drought and high temperatures. A pot assay was carried out to determine the ability of soil amendments to promote the survival and growth of the seedlings of two native species, Atriplex halimus L. (Amaranthaceae) and Bituminaria bituminosa (L.) C.H. Stirton (Fabaceae), in two heavy metal-contaminated soils, one of which also had a high level of arsenic (As). Restriction of A. halimus shoot growth in the non-amended soils appeared to be due to deficiency of nitrogen, phosphorus (P) and potassium (K) and in the more highly contaminated soil to lead (Pb) toxicity. Shoot biomass of A. halimus in the more highly contaminated soil was increased significantly by compost addition, due to increased uptake of K and P and decreased tissue Pb. The lack of effect of compost on B. bituminosa growth in this soil, despite a large increase in tissue K, may have been due to elevated tissue levels of As and Pb and the high soil salinity. The combination of A. halimus and compost addition seems appropriate for the phytostabilisation of contaminated semi-arid sites.

Poultry litter leachate (PLL) is known to contain a variety of contaminants including endocrine disrupting compounds (EDCs). This study analyzed the presence of steroids and contaminants in samples of poultry litter from a broiler poultry operation in Maryland, USA. Litter samples were homogenized, hydrated, incubated for two time periods (4 and 24 h) at two temperatures (20°C and 37°C), filtered, and analyzed for steroids and anthropogenic contaminants. In addition, duplicate samples were spiked with 17‐β estradiol (E2) and testosterone (T), and β-glucuronidase and aryl sulfatase, to measure steroid recovery and the presence of conjugates, respectively. A steroid recovery rate of 71 and 73% was obtained from E2 and T spiked samples, respectively. Increased incubation duration demonstrated an increased trend in E2 and a decreased trend in androgen (T and/or dihydrotestosterone [DHT]) concentrations, regardless of temperature. In contrast, increased incubation temperature displayed different trends in E2 and androgen concentrations. High temperature with a 4-h incubation resulted in an increased trend in androgen with no effect on E2. However, after 24 h of incubation at high temperature, an increased trend in E2 was observed with no effect on androgen. The presence of de-conjugating enzymes resulted in a greatly increased trend in T concentrations with a slight increased trend of E2 concentrations. Trace amounts of several metals and anthropogenic compounds were detected. Arsenic, barium, endosulfan, and bis (2-ethylhexyl) phthalate were detected at quantifiable levels. This study demonstrates that PLL contains potential EDCs and contaminants that can be toxic to, and bioaccumulate in, aquatic fauna. Determination of EDC concentrations in environmental samples is important to elucidate potential detrimental effects of agricultural runoff on aquatic wildlife.

The effect of activated sludge acclimation on the biodegradation of toluene and dimethyldisulphide (DMDS) in the presence of a non-aqueous phase liquid, polydimethylsiloxane (PDMS), in a two-phase partitioning bioreactor was characterized. The influence of the presence of PDMS, at a ratio of 25% (v/v), and acclimation of activated sludge on two hydrophobic VOC biodegradation was studied. Activated sludge were acclimated to each VOC and in the presence of the non-aqueous phase liquid, namely in the emulsion of PDMS in water. Using acclimated cells, 97.9% and 108.7% improvement of the mean biodegradation rates were recorded for toluene and DMDS, respectively, if compared to the values recorded in the absence of acclimation. While and in agreement with the lower solubility in water of DMDS if compared to toluene, a most significant effect of PDMS addition on the rate of DMDS removal was recorded, 87.0% and 153.6% for toluene and DMDS, respectively. In addition and if both biomass acclimation and PDMS addition were considered, overall improvements of the removal rates were 204% and 338% for toluene and DMDS.

Solution pH is among the most important parameters that influence heavy metal biosorption. This work presents a kinetic study of the effects of pH on chromium biosorption onto Cupressus lusitanica Mill bark from aqueous Cr(VI) or Cr(III) solutions and proposes a mechanism of adsorption. At all assayed contact times, the optimum pH for chromium biosorption from the Cr(III) solution was 5.0; in contrast, optimum pH for chromium biosorption from the Cr(VI) solution varied depending on contact time. The kinetic models that satisfactorily described the chromium biosorption processes from the Cr(III) and Cr(VI) solutions were the Elovich and pseudo second-order models, respectively. Diffuse reflectance infrared Fourier transform spectroscopy studies suggest that phenolic compounds present on C. lusitanica Mill bark play an important role in chromium biosorption from the Cr(III) solution. On the other hand, chromium biosorption from the Cr(VI) solution involved carboxyl groups produced on the bark by redox reactions between oxygen-containing groups and Cr(VI), and these were in turn responsible for the biosorption of Cr(III) produced by Cr(VI) reduction.