In this study, stable carbon and nitrogen isotope ratios in the samples of pine needles collected in 2013 and 2014 from heavily urbanized area in close proximity to point-source pollution emitters, such as a heat and power plant, nitrogen plant, and steelworks in Silesia (Poland), were analyzed as bio-indicators of contemporary environmental changes. The carbon isotope discrimination has been proposed as a method for evaluating water-use efficiency. The measurement of carbon and nitrogen isotopes was carried out using the continuous flow isotope ratio mass spectrometer. The isotope ratio mass spectrometer allows the precise measurement of mixtures of naturally occurring isotopes. The δ¹⁵N values were calibrated relative to the NO-3 and USGS34 international standards, whereas the δ¹³C values were calibrated relative to the C-3 and C-5 international standards. The strong year-to-year correlations between the δ¹³C in different sampling sites, and also the inter-annual correlation of δ¹⁵N values in the pine needles at each of the investigated sampling sites confirm that the measured δ¹³C and δ¹⁵N and also intrinsic water-use efficiency (iWUE) trends are representative of the sampling site. Diffuse air pollution caused the variation in δ ¹³C, δ¹⁵N, and iWUE dependent on type of emitter, the localization in the space (distance and direction) from factories and some local effect of other human activities. The complex short-term variation analysis can be helpful to distinguish isotopic fractionation, which is not an effect explainable by climatic conditions but by the anthropogenic effect. Between 2012 and 2014, an increase in iWUE is observed at leaf level.

This study assessed the suitability of passive sampler extracts for use with a GC-MS-database rapid screening technique for around 940 organic chemicals. Chemcatcher™ passive sampler systems containing either Empore™ SDB-XC or C18FF disks were deployed at 21 riverine sites in and near Melbourne, Victoria, Australia, for a period of 28 days during September–October 2008. Methanolic elution of the SDB-XC and C18FF disks produced an extract that, after evaporation and inversion into hexane, was compatible with the GC-MS-database method enabling over 30 chemicals to be observed. The sources of the non-agricultural chemicals are still unclear, but this study was conducted in a relatively dry season where total rainfall was approximately 40 % lower than the long-term mean for the catchment during the study period. Thus, the risks may be greater in wetter seasons, as greater quantities of chemicals are likely to reach waterways as the frequency, extent and intensity of surface run-off events increase. This study provides valuable information for policy and decision-makers, both in Australia and other regions of the world, in that passive sampling can be conveniently used prior to analysis by multi-residue techniques to produce data to assess the likely risks trace organic chemicals pose to aquatic ecosystems.

Biochar has great advantages and potentials on soil amendment and polluted soil remediation. In order to explore these applications, a pot experiment was carried out to research the effect of biochar on the heavy metal speciation in paddy soil and the heavy metal accumulation of paddy rice from Chengdu plain, Sichuan Province. The experimental results show that wine lees-derived biochar can efficiently increase soil pH, decrease the contents of soil exchangeable heavy metals, and promote heavy metal transformation to residual fraction. Moreover, application of biochar can reduce the accumulation of heavy metals in paddy plant, decrease the migration ability of heavy metals to the aboveground part of the plant, and consequently cut down contents of heavy metals in rice. When biochar dosage was 0.5 % in weight, the contents of soil exchangeable Cr, Ni, Cu, Pb, Zn, and Cd decreased 18.8, 29.6, 26.3, 23.0, 23.01, and 48.14 %, respectively, which all significantly differed from CK (P < 0.05), and the contents of heavy metals in plant roots, stems, leaves, rice husk, and rice all decreased accordingly, among which Zn, Cd, and Pb decreased 10.96, 8.89, and 8.33 % respectively. When biochar dosage increased to 1 %, heavy metal contents in roots, stems, leaves, rice husk, and rice decreased further. Therefore, wine lees-derived biochar shows a great potential in remediation of heavy-metal-polluted soil, and this work provides theoretical basis for restoring heavy-metal-polluted soil using biochar.

Iodinated contrast media (ICM), which are used for radiological visualization of human tissue and cardiovascular system, are poorly biodegradable; hence, new methods of their removal are sought. In this study, the effectiveness of selected X-ray ICM removal by means of UV and UV/TiO₂pretreatment processes from synthetic hospital wastewater was demonstrated. The following compounds were investigated: iodipamide, iohexol, and diatrizoate. The experiments were as follows: (i) estimated susceptibility of the ICM to decay by UV radiation in different aquatic matrices, (ii) determined an optimal retention time of hospital wastewater in the UV reactor, (iii) determined optimum TiO₂concentration to improve the effectiveness of the UV pretreatment, and (iv) investigated removal of ICM by combination of the photochemical and biological treatment methods. The quantum yields of selected ICM decay in deionized water (pH = 7.0) were established as 0.006, 0.004, and 0.029 for iohexol, diatrizoate, and iodipamide, respectively. Furthermore, the experiments revealed that diatrizoate and iohexol removal in the UV/TiO₂process is more efficient than in UV process alone. For diatrizoate, the removal efficiency equaled to 40 and 30 %, respectively, and for iohexol, the efficiency was 38 and 27 %, respectively. No significant increase in iodipamide removal in UV and UV/TiO₂processes was observed (29 and 28 %, respectively). However, highest removal efficiency was demonstrated in synthetic hospital wastewater with the combined photochemical and biological treatment method. The removal of diatrizoate and iohexol increased to at least 90 %, and for iodipamide, to at least 50 %.

A multivariate analysis was performed in the city of Florence (Italy) to investigate the influence of road traffic and meteorology on air pollution levels at urban traffic stations. Focussing on main traffic-related pollutants (CO, NO, NO₂, NO ₓ and PM₁₀), two typical urban road configurations were analysed: a street canyon and an open road. In addition to traffic flows, basic meteorological parameters were considered: wind speed, air temperature and relative humidity. The influence of all drivers by period of the year and day of the week was analysed with correlation analysis, while a statistical model was developed to predict concentrations at traffic stations by using predictors as urban background concentrations, traffic flows and a site-specific constant. Trained on a 1-year period (2008), the model was validated over an independent 1-year period (2007). The highest correlation of urban traffic concentrations was found vs. background concentrations, markedly for PM₁₀ (r = 0.85–0.87). The influence of road traffic was the highest for NO₂ (r = 0.51–0.58) and the lowest for PM₁₀ (r = 0.36–0.40). Urban-scale poor advection conditions proved to affect PM₁₀ peak levels more significantly than local traffic increase. For all pollutants, good forecasting capability was achieved by the developed statistical model, generally performing better at the street canyon (r = 0.79–0.86) than at the open road (r = 0.72–0.82).

We report on treatment and disposal of flue gas desulfurization (FGD) as a solid and hazardous waste. The effects of modified flue gas desulfurization residue (MFGDR) prepared by calcining a mixture of dry/semi-dry FGD residue, potassium feldspar, and/or limestone power on growth of plant and soil amelioration are investigated. The effect of MFGDR on the sweet potato was evaluated by analyzing the soil physiochemical properties and heavy metal speciation in the soil, and the yield, quality, and heavy metal concentrations of the sweet potato. The results indicated that applying MFGDR as soil ameliorant increased total yield by 53.38 %, safety, and the quality of sweet potato. The concentrations of Cd, Cr, Cu, Pb, and As in the sweet potato reduced by 31.34, 70.57, 22.17, 79.49, and 100 %, respectively. The improvements were attributed to enhancement of soil mineral composition contained in MFGDR. The MFGDR could also improve the soil physicochemical properties and decreased phytoavailability of heavy metals. The application of MFGDR in agriculture not only was a potential and useful technique for recycling and utilization of FGD residue, but also had potential benefits for soil amelioration, plant growth, and decrease of heavy metals in grown products.

We need specific and competent adsorbents to remove arsenic and bring it down to permissible levels in drinking water. Therefore, industrial byproducts are extensively applied to produce large amounts of natural adsorbents. Similarly, managing optimum arsenic adsorption with palm oil clinker sand (POCS) is possible through a careful statistical planning of adsorption variables. We plan and perform a minimum number of experiments to (1) obtain optimum arsenic adsorption and (2) provide a new possible application opportunity to the industrial waste managers and future planners. We observed that adsorption of arsenic was dependent on the pH of the system, initial concentration of arsenic (mg L⁻¹), amount (mg) of POCS, and temperature of the bio-adsorption system. A correlation among the study variables was constructed by three-dimensional (3D) response surfaces and two-dimensional (2D) contour plots based on central composite design (CCD) experiments in a batch mode of study. A quadratic model fitted well with the experimental data and better explained the superiority of current bio-adsorption system and efficient removal of arsenic from water samples. We confirmed that the selected variables were experimentally and statistically significant and controlled the overall adsorption response by the batch system. A comparative and thorough analysis of the adsorption process confirmed that selected variables were mutually interacting in a nonlinear fashion in this study. Excellent experimental results and external comparative studies prove the relative importance of the present model and adsorption system for arsenic remediation biotechnology.

The reversible and resistant components of adsorption and desorption of munition constituents (MCs) on soils was studied to determine the environmental fate of these contaminants. The long-term desorption of MCs has applicability in formulating accurate risk assessments for operational military ranges. Batch experiments near 1:1 (w/v) soil-to-solution ratios reflecting field conditions using solutions containing mixtures of HMX, RDX, and nitroglycerine (NG) were conducted. The three soils used varied from 0.04 to 13.3 % organic matter. The experiment involved one adsorption step followed by four consecutive desorption steps. Adsorption times were 2, 5, 10, and 30 days. For each adsorption time, desorption times were carried out for 1, 12, 24 and 72 h and 30 days. The reversible/resistant component model was applied to the data. The model predicted the desorption concentrations of the MCs in the soil with root mean square errors of approximately 0.05 to 0.2 μg g soil⁻¹. The extent of desorption hysteresis is not changed by the length of desorption time, irrespective of the initial adsorption time.

A coupling technique is developed to predict the behavior of a buoyant river plume in a lake. The model incorporates a 3D hydrodynamic model (POMGL) and a 3D particle tracking model (Partic3D) for the far-field transport computations. The source conditions for the particle tracking model are obtained from a near-field model derived from the characteristics of the plume analyzed from extensive field studies on the Grand River plume, Lake Michigan. The empirical near-field model was developed to predict the geometry of the plume, dilution, and centerline trajectory near the river mouth, and to provide the concentration and location of the particles to be released in the far field. The coupled empirical-numerical model shows improved predictions in the near field versus the single numerical model. The present results strongly advocate the use of model combinations in order to improve coastal diffusion and transport processes. The primary application of the technique is in recreational water early-warning and forecasting systems that will estimate the immediate and short-term risk of exceeding pathogen indicator concentration criteria in lakes and coastal areas.

The large spatial heterogeneity in soil physico-chemical and microbial parameters challenges our ability to predict and model pesticide leaching from agricultural land. Microbial mineralization of pesticides is an important process with respect to pesticide leaching since mineralization is the major process for the complete degradation of pesticides without generation of metabolites. The aim of our study was to determine field-scale variation in the potential for mineralization of the herbicides glyphosate, bromoxyniloctanoate, diflufenican, and bentazone and to investigate whether this variation can be predicted by variations in basic soil parameters. Sixty-five soil samples were sampled from an agricultural, loamy field in Silstrup, Denmark, from a 60 × 165 m rectangular grid. The mineralization potential of the four pesticides was determined using a 96-well microplate ¹⁴C-radiorespirometric method. Initial mineralization rates were determined using first-order kinetics for glyphosate and bromoxyniloctanoate and zero-order kinetics for diflufenican and bentazone. The mineralization rates of the four pesticides varied between the different pesticides and the different soil samples, but we could not establish correlations between the pesticide mineralization rates and the measured soil parameters. Only the glyphosate mineralization rates showed slightly increasing mineralization potentials towards the northern area of the field, with increasing clay and decreasing OC contents. The mineralization potentials for glyphosate and bentazone were compared with 9-years leaching data from two horizontal wells 3.5 m below the field. The field-scale leaching patterns, however, could not be explained by the pesticide mineralization data. Instead, field-scale pesticide leaching may have been governed by soil structure and preferential flow events.