Carbonic anhydrase (CA) has been immobilized on chitosan stabilized iron nanoparticles (CSIN) for the biomimetic carbonation reaction. CSIN was characterized using scanning electron microscope, energy dispersive X-ray, X-ray diffraction spectroscopy, and Fourier transform infrared analysis. The effect of various parameters such as pH, temperature and storage stability, on immobilized CA was investigated using a p-NPA assay. Kinetic parameters of immobilized and free CA (K ₘ and V ₘₐₓ values) were also evaluated. The K ₘ and V ₘₐₓ for immobilized CA was 1.727 mM and 1.189 μmol min⁻¹ ml⁻¹, respectively, whereas for free enzyme the K ₘ and V ₘₐₓ was 1.594 mM and 1.307 μmol min⁻¹ ml⁻¹, respectively. It was observed that the immobilized enzyme had longer storage stability and retained 50 % of its initial activity upto 30 days at room temperature. CA immobilized on CSIN has been used for hydration of CO₂, and the results were validated by using a gas chromatographic method. Proof of concept has been established for the biomimetic carbonation reaction. Immobilized CA show reasonably good CO₂ sequestration capacity of 21.55 mg of CaCO₃/mg of CA as compared to CO₂ sequestration capacity of 34.92 mg of CaCO₃/mg of CA for free CA respectively, under a limiting concentration of CO₂ (14.5 mg of CO₂/10 ml).

The mining exploitation of metallic sulphides, together with the activities associated to the mineral treatment and smelting, when maintained through centuries due to the wealth of the ores, generate important accumulations of wastes in structures of different kind of tailing dams and ponds, for instance. When no previous corrective steps are taken, as usually happens in old exploitations, this means a serious risk of environmental pollution, due to the mobilisation of heavy metals. The present study has been carried out in a mining district, actively exploited during the last two millennia, that was the first world’s producer of lead during some periods (Linares-La Carolina, southern Spain). In this district, the mining activity was associated to a philonian network of metallic sulphurs and ended by the 1980s of the past century. The ancient mining operations, mostly subterranean, have generated large accumulations of residues without any prior corrective action. Therefore, this work intends to characterise these mining dams and determine the influence of these mining wastes on the quality of surface and ground waters. With this goal, three structures that store the mining refuse of different mineralogical origin have been selected. First, a geochemical characterisation of the soil was performed in the area surrounding each of the structures. In all cases, high levels of trace elements (including Pb, Zn, Cu, Cd, Mn, As, Sb and Ba) were observed. A hydrochemical study revealed the mobilisation through the aqueous medium of certain contaminants from the leachate of these ancient accumulations; these contaminants will flow to the streams that drain the area or to the aquifers of the sector. The internal characterisation of these structures was performed with geophysical techniques, specifically electrical resistivity imaging (ERI). The six generated resistivity models have allowed the identification of the morphology of the structures, variations in the vertical and horizontal distribution of the deposited material, fracture zones, water content and reload–unload zones and the contact of the mining wastes with the substrate. Thus, the ERI study confirms the lack of impermeabilisation measures for the terrain in the spill zones in all three cases, which indicates a high risk of contamination of the soil and waters. The obtained images also permit the identification of the ideal positions to conduct future borehole controls.

This paper presents a new tool, developed with the aim of assessing the environmental impact from industrial effluents and sewage systems in Hanumante River and to recommend the finest procedures to control water pollution so as to improve the water quality of Hanumante River using environmental system analysis. Hanumante River is heavily polluted due to inefficient management resulting in water-associated problems. The time horizon for this study is from 2000 to 2030, yearly, and the spatial boundary is considered to be Hanumante River, Bhaktapur, Nepal. The stakeholder, function, and scenario analyses are employed as three tools for study. The participation of main stakeholders aids in resolving their various conflicting interests in Hanumante River, thus creating a common understanding about the crisis under study. A complete functional analysis illustrates various functions fulfilled by the river and their associated services. Based on the interests of the stakeholders and their priorities, two alternatives resulting in four scenarios are identified and ranked against four selected criteria. A combination of improved industrial technology and efficient municipal waste management gives the best solution to the pollution problem in Hanumante River. Different alternative themes have corresponding effects on the selected criteria. The choice is in the hands of the decision makers of Bhaktapur City. The outcome of this paper will ultimately help decision and policy makers to analyze the environmental impact of river systems and find efficient and better-quality decision making for water resource management incorporating the knowledge and experiences of various stakeholders.

This review addresses the quantification of anthropogenic pollutants in lacustrine sediments by multidisciplinary analyses including: chronostratigraphy using radioisotopes (¹³⁷Cs) and radiocarbon dates (¹⁴C), trace metal analysis, faecal indicator analysis, as well as antibiotic-resistant genes by molecular analysis. Sediment cores from lakes Lucerne and Geneva that are located at a distance of 150 km from each other reveal a synchronous increase in anthropogenic trace metals (Pb, Cu, Zn, and Mn) following the industrial revolution in Europe about 1850. In both lakes, the peak of water pollution by toxic metals due to discharge of industrial wastewaters was reached in the middle of the twentieth century. During the second part of the twentieth century, both sites show a decrease in metal pollution following the implementation of wastewater treatment plants. On the contrary, the Vidy Bay of Lake Geneva where the treated wastewaters from the city of Lausanne are released since 1964 points out a dramatic increase in trace metal deposition. Later, a high increase in organic matter deposition, in bacteria (Escherichia coli and Enterococcus faecalis) activity as well as antibiotic-resistant genes and bacteria occurred into the bay, simultaneously with the eutrophication of the large and deep perialpine lakes in the 1970s due to excessive external nutrient loading.

Atmospheric carbonyl sulfide (COS) mixing ratios measured over 24 h during five summer campaigns (2003–2007) in a forest at the foot of Mt. Fuji, Japan (35°21′ N, 138°43′ E; 1,300 m above sea level, a.s.l.) and at the summit (3,776 m a.s.l.) were compared. COS levels were lower at the foot than at the summit during four out of five summer campaigns. The ratios of COS mixing ratios at the foot of Mt. Fuji to those at the summit ranged from 0.7 to 0.9. These results provide evidence of biological consumption of COS in the East Asian atmospheric boundary layer. We also measured the vertical profile of ambient COS below the forest canopy. These data showed a clear gradient of COS mixing ratio: in the lowermost 1 m of the boundary layer, COS mixing ratios decreased markedly downward. Two of the different kinds of vertical distribution of COS presented here support the role of soil as a sink of atmospheric COS described by previous research using dynamic enclosure experiments.

Lead is a well-known pollutant with documented toxicity. Lead-containing weights used to balance motor vehicle wheels are regularly lost from vehicles and enter the environment. Lead weights deposited on roadways in the vicinity of Trenton, NJ were gathered and measured from February 2006 to January 2009. Measurements included loss of mass from specific weights exposed to traffic. Extrapolation of the results to the entire state suggests that approximately 12 tons per year of lead in the form of wheel weights are deposited on New Jersey roadways, and that approximately 40 kg of lead enters the environment in the form of small particles formed from the abrasion and grinding action of traffic on weights deposited on roadways. This quantity of small particles is much less than the approximately 60 tons per year of lead estimated by an earlier study to enter New Jersey in precipitation, some of which may result from the combustion of leaded aviation fuel. The quantity is also likely small compared with the fluxes of lead into the environment that still continue from leaded paint and with the residue of finely dispersed lead from historical uses of leaded gas in motor vehicles that remains in the environment. The quantity of lead released to the environment in the form of wheel weights appears likely to decline in the future because of legislation, voluntary phase-outs by manufacturers, and new trends in wheel technology

This paper presents for the first time the technological potential of novel Lantana camara-reinforced ethylene vinyl acetate (EVA) composites fabricated via the melt-blending technique. The composite and L. camara were characterized using X-ray diffraction spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and deferential scanning calorimeter. L. camara was found to drastically reduce the crystallinity of EVA from 44.3 % to a minimum of 1.16 %. Immersion of the composite specimens in de-ionised water showed that moisture absorption was less significant for composites with L. camara contents less than 15 % (w/w). A maximum sorption capacity of 1.20 mol% was recorded in 42 h which is remarkable considering the hydrophobic nature of EVA with 9 % vinyl acetate. L. camara and the composite removed 96 % and 88 % para-nitrophenol from water, respectively.

We examined a performance of the multiplicative stomatal conductance model to estimate the stomatal ozone uptake for Fagus crenata. Parameterization of the model was carried out by in-situ measurements in a free-air ozone exposure experiment. The model performed fairly well under ambient conditions, with low ozone concentration. However, the model overestimated stomatal conductance under enhanced ozone condition due to ozone-induced stomatal closure. A revised model that included a parameter representing ozone-induced stomatal closure showed better estimation of ozone uptake. Neglecting ozone-induced stomatal closure induced a 20 % overestimation of the stomatal uptake of ozone. The ozone-induced stomatal closure was closely related to stomatal ozone uptake rather than accumulated concentrations of ozone exceeding 40 nmol mol⁻¹. Our results suggest that ozone-induced stomatal closure should be implemented to stomatal conductance model for estimating ozone uptake for F. crenata. The implementation will contribute to adequate risk assessments of ozone impacts on F. crenata forests in Japan.

This paper analyses the influence of activated sludge technologies on the Particle Size Distribution (PSD) of urban wastewater treatment plants operating under real conditions. The activated sludge treatment systems selected for the analysis are the most widely used in wastewater treatment installations: (a) double step activated sludge, (b) medium load activated sludge, (c) prolonged aeration, and (d) membrane bioreactors The main quality parameters (suspended solids, turbidity, and COD) and PSD in the influent and effluent of each different activated sludge treatment were analyzed during 1 year. The PSD was fitted using the power law ([Formula: see text]) obtaining coefficients A and b to define the particle distribution. Mathematical correlations between this coefficients and the rest of parameters studied were found [Formula: see text]. The relation with the average particle size by mass was also found, ([Formula: see text]). Moreover, a relation between PSD and the particle elimination efficiency of the secondary treatment was study, ([Formula: see text]). Finally, the particulate matter nature was assessed by SEM-EDX. It can be concluded that membrane bioreactor is the technology that produces the best water quality effluent due to physic process of particle separation by ultrafiltration membrane technology.

The aim was to study the influence of soil properties on the leaching of nitrate, phosphate and organic matter (OM) following the application of sewage sludge to contrasting soils. Seventy agricultural soils from different parts of Spain were amended with sewage sludge (50 t dry weight ha−1), and a controlled column study was developed. After 2, 4 and 6 months of incubation, distilled water, equivalent to an autumn rainfall event of 25 l m−2 in Mediterranean environments, was applied and leachates collected and analysed: pH, electrical conductivity (EC), chemical oxygen demand (COD), phosphate and nitrate. The mean values of pH in the leachates after 2, 4 and 6 months were similar and close to the neutrality. The highest concentrations for the rest of the parameters analysed were found after 2 months of incubation and diminished for 4 and 6 months, especially COD. Soil pH and texture were the most relevant soil properties controlling the leaching of the analysed parameters. The OM mineralization seemed to be enhanced at high values of soil pH, thus increasing the nitrate and reducing the COD leaching. However, phosphate levels were reduced at high values of soil pH. In addition, leaching was promoted in sandy soils. Other soil properties influenced phosphate leaching being the equivalent calcium carbonate soil content as the most relevant. Soil organic carbon was negatively related to the EC and nitrate concentration in the leachates but resulting in a weak contribution compared with soil pH and texture. Concerns about nitrate pollution have been confirmed.