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[en] Antibiotics are widely used in daily life but their abuse has posed a potential threat to human health. The interaction between human serum albumin (HSA) and sulfamethazine (SMZ) was investigated by capillary electrophoresis, fluorescence spectrometry, and circular dichroism. The binding constant and site were determined to be 1.09 × 104 M−1 and 1.14 at 309.5 K. The thermodynamic determination indicated that the interaction was driven by enthalpy change, where the electrostatic interaction and hydrogen bond were the dominant binding force. The binding distance between SMZ and tryptophan residue of HSA was obtained to be 3.07 nm according to Förster non-radioactive energy transfer theory. The site marker competition revealed that SMZ bound into subdomain IIA of HSA. The binding of SMZ induced the unfolding of the polypeptides of HSA and transferred the secondary conformation of HSA. The equilibrium dialysis showed that only 0.13 mM SMZ decreased vitamin B2 by 38% transported on the HSA. This work provides a new quantitative evaluation method for antibiotics to cause the protein damage. -- Highlights: ► Various techniques characterized the interactions between SMZ and HSA. ► The electrostatic interaction and hydrogen bond dominated in the interaction. ► SMZ induced the conformation change of HSA. ► SMZ affected the transportation function of HSA.
[en] To better understand the spatial dynamics of non-point source (NPS) phosphorus loading with soil property at watershed scale, integrated modeling and soil chemistry is crucial to ensure that the indicator is functioning properly and expressing the spatial interaction at two depths. Developments in distributed modeling have greatly enriched the availability of geospatial data analysis and assess the NPS pollution loading response to soil property over larger area. The 1.5 km-grid soil sampling at two depths was analyzed with eight parameters, which provided detailed spatial and vertical soil data under four main types of landuses. The impacts of landuse conversion and agricultural practice on soil property were firstly identified. Except for the slightly bigger total of potassium (TK) and cadmium (Cr), the other six parameters had larger content in 20–40 cm surface than the top 20 cm surface. The Soil and Water Assessment Tool was employed to simulate the loading of NPS phosphorus. Overlaying with the landuse distribution, it was found that the NPS phosphorus mainly comes from the subbasins dominated with upland and paddy rice. The linear correlations of eight soil parameters at two depths with NPS phosphorus loading in the subbasins of upland and paddy rice were compared, respectively. The correlations of available phosphorus (AP), total phosphorus (TP), total nitrogen (TN) and TK varied in two depths, and also can assess the loading. The soil with lower soil organic carbon (SOC) presented a significant higher risk for NPS phosphorus loading, especially in agricultural area. The Principal Component Analysis showed that the TP and zinc (Zn) in top soil and copper (Cu) and Cr in subsurface can work as indicators. The analysis suggested that the application of soil property indicators is useful for assessing NPS phosphorus loss, which is promising for water safety in agricultural area. -- Highlights: ► Spatial dynamics of NPS phosphorus pollution with soil property at watershed scale are analyzed. ► Impacts of agricultural practice on soil property at spatial and vertical are identified. ► Eight soil parameters at two depths observe different patterns with NPS phosphorus loading. ► Watershed soil copper and cadmium in subsurface are useful indicators.
[en] Soil beneath a stormwater infiltration basin receiving runoff from a 23 ha predominantly residential watershed in north-central Florida, USA, was amended using biosorption activated media (BAM) to study the effectiveness of this technology in reducing inputs of nitrogen and phosphorus to groundwater. The functionalized soil amendment BAM consists of a 1.0:1.9:4.1 mixture (by volume) of tire crumb (to increase sorption capacity), silt and clay (to increase soil moisture retention), and sand (to promote sufficient infiltration), which was applied to develop an innovative stormwater infiltration basin utilizing nutrient reduction and flood control sub-basins. Comparison of nitrate/chloride (NO3−/Cl−) ratios for the shallow groundwater indicates that prior to using BAM, NO3− concentrations were substantially influenced by nitrification or variations in NO3− input. In contrast, for the new basin utilizing BAM, NO3−/Cl− ratios indicate minor nitrification and NO3− losses with the exception of one summer sample that indicated a 45% loss. Biogeochemical indicators (denitrifier activity derived from real-time polymerase chain reaction and variations in major ions, nutrients, dissolved and soil gases, and stable isotopes) suggest that NO3− losses are primarily attributable to denitrification, whereas dissimilatory nitrate reduction to ammonium is a minor process. Denitrification was likely occurring intermittently in anoxic microsites in the unsaturated zone, which was enhanced by the increased soil moisture within the BAM layer and resultant reductions in surface/subsurface oxygen exchange that produced conditions conducive to increased denitrifier activity. Concentrations of total dissolved phosphorus and orthophosphate (PO43−) were reduced by more than 70% in unsaturated zone soil water, with the largest decreases in the BAM layer where sorption was the most likely mechanism for removal. Post-BAM PO43−/Cl− ratios for shallow groundwater indicate predominantly minor increases and decreases in PO43− with the exception of one summer sample that indicated a 50% loss. Differences in nutrient variations between the unsaturated zone and shallow groundwater may be the result of the intensity and duration of nutrient removal processes and mixing ratios with water that had undergone little biogeochemical transformation. Observed nitrogen and phosphorus losses demonstrate the potential, as well as the future research needs to improve performance, of the innovative stormwater infiltration basin using BAM for providing passive, economical, stormwater nutrient-treatment technology to support green infrastructure. -- Highlights: ► New technology to control nutrient leaching beneath stormwater infiltration basins. ► Integrated nutrient reduction and flood control sub-basins. ► Biosorption activated media (BAM) promotes sorption and soil moisture retention. ► Soil moisture retention is key BAM function promoting biogeochemical processes. ► Documented decreases in nitrogen and phosphorus species.
[en] Alluvial soils are reservoirs of metal contaminants such as Pb that originate from many different sources and are integrated temporally and spatially through erosional and depositional processes. In this study the source, lability and solubility of Pb were examined in a range of alluvial soils from the middle and lower River Trent and its tributary the River Dove using Pb isotope apportionment and isotopic dilution. All samples were collected within 10 m of the river bank to represent the soil that is most likely to be remobilised during bank erosion. Paired samples were taken from the topsoil (0–15 cm) and subsoil (35–50 cm) to assess differences with depth. Lead concentrations in soil ranged from 43 to 1282 mg/kg. The lability of soil Pb varied between 9 and 56% of total metal concentration whilst Pb concentrations in pore water varied between 0.2 and 6.5 μg/L. There was little difference in the % Pb lability between paired top and sub soils, possibly because soil characteristics such as pH, iron oxides and clay content were generally similar; a result of the recycling of eroded and deposited soils within the river system. Soil pH was found to be negatively correlated with % Pb lability. Source apportionment using 206Pb/207Pb and 208Pb/207Pb ratios showed that the isotopic ratios of Pb in the total, labile and solution pools fitted along a mixing line between Broken Hill Type (‘BHT’) Pb, used as an additive in UK petrol, and the local coal/Southern Pennine ore Pb. Various anomalies were found in the Pb isotopes of the bankside alluvial soils which were explained by point source pollution. Statistically significant differences were found between (i) the isotopic composition of Pb in the total soil pool and the labile/solution pools and (ii) the isotopic composition of Pb in the labile and solution pools, suggesting an enrichment of recent non-Pennine sources of Pb entering the soils in the labile and solution pools. -- Highlights: ► The labile pool of Pb in alluvial soils ranges from 9 to 56% of the total pool. ► The lability of Pb (as %) is negatively correlated with soil pH. ► Evidence for post-depositional vertical migration of petrol-derived Pb was found. ► Petrol Pb is enriched in the labile and pore water pools compared to the total pool.
[en] This study deals with the characteristics of throughfall produced by vine (Vitis vinifera L.) in one of the most common pedoclimatic conditions for grape production: a soil derived from marine sediments under a temperate Mediterranean climate, and located rather close to the seacoast. To distinguish the contribution of the plant from that of the atmospheric deposition, the throughfall was collected for more than one year under real and artificial (plastic) vines; for the same period, also the bulk precipitation was collected. The solution collected were analysed for pH, electrical conductivity, and concentration of cations and anions. For each event, the ionic fluxes of bulk precipitation and throughfall were calculated. Results indicated that the chemical composition of the bulk precipitation was strongly influenced by the proximity of the seashore and, to a lesser extent, by local anthropic activities and windblown material coming from distant areas. The chemical composition of the throughfall was affected by the same factors of bulk precipitation, but also by solubilisation of dry deposition trapped by the canopies, agronomic practices, plant, and living-on-the-leaves microorganisms. The comparison of the characteristics of the throughfall of the real with the artificial vines revealed that the vines are a source of Mg and K. During winter season, the reduction of Ca, NH4 and PO4 from bulk precipitation to throughfall was ascribed to the formation of biogenic minerals on the plant surface. The presence of these minerals was proved by X-ray diffraction on the powders collected during the winter season on the surface of cordons and fruiting canes. We conclude that an approach to the estimation of the nutritional potentiality of the soil that includes the contribution of the throughfall is functional to the management of the agro-ecosystem. -- Highlights: ► The characteristics of the throughfall of vines are affected by agronomic practices. ► Throughfall contributes to the nutrient cycles through solubilisation of dry depositions. ► Bio-minerals form on the plant surfaces. ► The contribution of the TF is functional to the management of the agro-ecosystem.
[en] Little is known about atmospheric input of beryllium (Be) into ecosystems, despite its highly toxic behavior. For three consecutive winters (2009–2011), we measured Be concentrations in horizontal deposition (rime) and vertical deposition (snow) at 10 remote mountain-top locations in the Czech Republic, Central Europe. Beryllium was determined both in filtered waters, and in HF digests of insoluble particles. Across the sites, soluble Be concentrations in rime were 7 times higher, compared to snow (6.1 vs. 0.9 ng·L−1). Rime scavenged the pollution-rich lower segments of clouds. The lowest Be concentrations were detected in the soluble fraction of snow. Across the sites, 34% of total Be deposition occurred in the form of soluble (bioavailable) Be, the rest were insoluble particles. Beryllium fluxes decreased in the order: vertical dry deposition insoluble > vertical dry deposition soluble > horizontal deposition soluble > vertical wet deposition insoluble > vertical wet deposition soluble > horizontal deposition insoluble. The average contributions of these Be forms to total deposition were 56, 21, 8, 7, 5 and 3%, respectively. Sites in the northeast were more Be-polluted than the rest of the country with sources of pollution in industrial Silesia. -- Highlights: ► We measured Be concentrations in rime and snow in the Czech Republic. ► Soluble Be concentrations in rime were 7 times higher than in snow. ► 34% of total Be deposition occurred in the form of soluble (bioavailable) Be. ► Dry-deposited fluxes dominated Be inputs. ► Soluble Be concentrations only rarely exceeded 30 ng·L−1.
[en] The study of microbial life in building materials is an emerging topic concerning biodeterioration of materials as well as health risks in houses and at working places. Biodegradation and potential health implications associated with microbial growth in our residues claim for more precise methods for quantification and identification. To date, cultivation experiments are commonly used to gain insight into the microbial diversity. Nowadays, molecular techniques for the identification of microorganisms provide efficient methods that can be applied in this field. The efficiency of DNA extraction is decisive in order to perform a reliable and reproducible quantification of the microorganisms by qPCR or to characterize the structure of the microbial community. In this study we tested thirteen DNA extraction methods and evaluated their efficiency for identifying (1) the quantity of DNA, (2) the quality and purity of DNA and (3) the ability of the DNA to be amplified in a PCR reaction using three universal primer sets for the ITS region of fungi as well as one primer pair targeting the 16S rRNA of bacteria with three typical building materials — common plaster, red brick and gypsum cardboard. DNA concentration measurements showed strong variations among the tested methods and materials. Measurement of the DNA yield showed up to three orders of magnitude variation from the same samples, whereas A260/A280 ratios often prognosticated biases in the PCR amplifications. Visualization of the crude DNA extracts and the comparison of DGGE fingerprints showed additional drawbacks of some methods. The FastDNA Spin kit for soil showed to be the best DNA extraction method and could provide positive results for all tests with the three building materials. Therefore, we suggest this method as a gold standard for quantification of indoor fungi and bacteria in building materials. -- Highlights: ► Up to thirteen extraction methods were evaluated with three building materials. ► Plaster, red brick and gypsum cardboard were chosen as representative materials. ► DNA yield, DNA purity and PCR amplifiability were the decisive parameters. ► The results from the DNA yield showed fluctuations of up to 3 orders of magnitude. ► The FastDNA Spin kit is the best DNA isolation method for building materials.
[en] The impact of the operating Ignalina Nuclear Power Plant (INPP) on the contamination of top soil layer with artificial radionuclides has been studied. Results of the investigation of artificial gamma-ray emitting radionuclide distribution in soil in the vicinity of the INPP and distant regions in Lithuania in 1996–2008 (INPP operational period) show that nowadays 137Cs remains the most important artificial gamma-ray emitting radionuclide in the upper soil layer. Mean 137Cs activity concentrations in the top soil layer in the vicinity of the INPP were found to be significantly lower compared to those in remote regions of Varėna and Plungė (∼ 300 km from INPP). In 1996 and 1998 mean 137Cs activity concentrations were in the range of 28–45 Bq/kg in the nearest vicinity to the INPP, 103 Bq/kg in Varėna and 340 Bq/kg in Plungė region. 137Cs activity concentrations were 5–20 times lower in meadow soil (4–14 Bq/kg) compared to swamp and forest soil. 60Co, the INPP origin radionuclide, was detected in samples only in 1996 and 2000, and the activity concentration of 60Co was found to be in the range from 0.4 to 7.0 Bq/kg at the sampling ground nearest to the INPP. Average annual activity concentrations of the INPP origin 137Cs and 60Co in the air and depositions in the INPP region were modeled using Pasquill–Gifford equations. The modeling results of 137Cs and 60Co depositional load in the INPP vicinity agree with the experimentally obtained values. Our results provide the evidence that the operation of INPP did not cause any significant contamination in soil surface. -- Highlights: ► Gamma-emitters in top soil were studied during the operational period of the Ignalina NPP. ► Only 137Cs was detected in each sample of the top soil in studied regions every year. ► The mean 137Cs activity in the top soil of the INPP vicinity was lower than in remote regions. ► The INPP origin 60Co and 137Cs deposition loads were modeled. ► Theoretically obtained data were compared to experimental results.
[en] The widely used antihistamine diphenhydramine is present in municipal biosolids, and is detected in runoff from agricultural land fertilized with biosolids. In the present study the kinetics and major pathways of diphenhydramine dissipation in a loam, sandy loam, and clay loam soil were determined in laboratory incubations. The time to dissipate 50% (DT50) of 14C-diphenhydramine residues at 30 °C ranged from 88 ± 28 days in the clay loam to 335 ± 145 days in the loam soil. Mineralization of 14C was insignificant, and diphenhydramine-N-oxide was the only detected extractable transformation product elucidated by radioisotope and HPLC-MS methods. There were no significant effects of municipal biosolids on the kinetics or pathways of removal. Overall, diphenhydramine is quite persistent in soils, and formation of non-extractable soil-bound residues is the major mechanism of diphenhydramine dissipation. -- Highlights: ► Diphenhydramine is a widely used antihistamine drug, is found in biosolids, and in runoff from biosolids-fertilized fields. ► The persistence of 14C-diphenhydramine was evaluated in soils. ► Half lives ranged from 88 to 335 days. Diphenhydramine-N-oxide was the only detected transformation product. ► Soil-bound residues was a major sink.
[en] The impact of land transportation on local soil environments is an important topic in environmental and ecological sciences. The rapid development of transportation infrastructure lends increasing importance to studies that identify and evaluate related heavy metal pollution. This paper discusses the effects of railways on soil heavy metal enrichments in the Tibetan plateau. At a representative area along the Haergai–Delingha railway, lead, cadmium, copper, zinc, chromium, nickel, cobalt, and vanadium were measured in 127 topsoil samples (0–10 cm depth). The results indicate that railway transport has a significant effect on the concentration of Zn, Cd and Pb in the soil, with levels of enrichment ranging from no pollution to significant pollution. The affected area was within 20 m of the railway. The soil at Delingha was the most contaminated soil with heavy metals, and the enrichment level of Cd in the soil was the highest along the Qinghai–Tibet railway. The horizontal distributions of the three heavy metals present different characteristics at different sampling sites, which may be due to discrepancies in terrain and vegetation types. Alkaline soils and guardrails along the railway might reduce the effect of soil pollution on local people and animals. -- Highlights: ► Levels of Zn, Cd and Pb in soils are affected by railway transportation. ► Cadmium enrichment is especially high. ► The affected area for these pollutants was within 20 m of the railway. ► The distributions of metal presented different characteristics in different sites.