Dispersion of pollutants over land–water–land interface: Study using CALPUFF model

The CALMET/CALPUFF modeling system is used to study atmospheric dispersion of pollutant over land–water–land interface. It is shown that the default scheme used by CALMET/CALPUFF to handle inhomogeneous surfaces does not take care of the different turbulence characteristics over such surfaces. An alternative method is suggested to incorporate different turbulent characteristics over inhomogeneous surfaces by using the appropriate atmospheric stability category over different surfaces. The results show that the presence of water body can increase the ground level concentration by a factor of up to 50 for the width of water body varying from 1 km to 5 km. It is also shown that the effect of water body on the ground level concentration decreases as the distance from the water body increases. The present study showed that for land–water interface, the realistic specification of turbulence characteristics over inhomogeneous surfaces significantly changes the estimation of ground level concentration as compared to the default scheme available in the CALMET/CALPUFF modeling system and is expected to give realistic results.     

Enantioselective hydrolysis and photolysis of mandipropamid in different aquatic environments — evaluation of influencing factors

Environmental Science and Pollution Research - The hydrolysis and photolysis of the chiral fungicide mandipropamid were investigated, and the potential enantioselectivity of mandipropamid in...     

Process envelopes for stabilisation/solidification of contaminated soil using lime–slag blend

Purpose  

Stabilisation/solidification (S/S) has emerged as an efficient and cost-effective technology for the treatment of contaminated soils. However, the performance of S/S-treated soils is governed by several intercorrelated variables, which complicates the optimisation of the treatment process design. Therefore, it is desirable to develop process envelopes, which define the range of operating variables that result in acceptable performance.     

An evaluation of sulfate in European precipitation 1955–1982

More than 25 years of data on sulfate in precipitation from the European Air Chemistry Network (EACN) are analysed for seasonal and long-term trends and their spatial variability. The number of stations has varied between about 50 and 100, all of them located in the central and northern parts of western Europe. Despite considerable shortcomings of the data (indicated among other things by poor ionic balance during several years, particularly in the late 1950s and the early 1960s) the following conclusions are drawn.In Norway, Sweden, Denmark and Finland, the sulfate concentration increased by roughly 50 per cent between the late 1950s and the late 1960s. A further increase during the 1970s is indicated at the Danish stations but most stations in Sweden and Norway show a decline by on the average about 20 per cent since the early 1970s. Sulfate data from the U.K. and the European continent seem to exhibit less systematic variations.A comparison between the long-term changes in the Scandinavian data on sulfate in precipitation and the corresponding changes in anthropogenic SO₂ emission in Europe indicates a fair agreement with regard both to the increase in emission during the 1950s and 1960s and, except for the Danish stations, also the subsequent decrease in emission in several of the West European countries.In most parts of the network the annual cycle of concentration of sulfate exhibits a maximum in February through May and a minimum in July to October, whereas the wet deposition normally has its maximum in May to August and minimum in December to March. A comparison with the annual cycle of anthropogenic emission, which has a clear maximum in December to March, indicates that the fraction of sulfur exported out of the region is larger in winter than in summer.     

Quantitative evaluation of environmental risks of flotation tailings from hydrothermal sulfidation–flotation process

Floatation tailings (FT) are the main by-products of the hydrothermal sulfidation–flotation process. FT (FT₁ and FT₂) were obtained by treating two different neutralization sludges (NS) (NS₁ and NS₂). This paper quantitatively evaluated the environmental risks of heavy metals (Zn, Cd, Cu, Pb, and As) in FT versus NS. The total concentration and leaching rates (R ₂) of heavy metals in FT were much lower than those in NS, demonstrating that the hydrothermal sulfidation–flotation process was able to effectively suppress the mobility and leachability of heavy metals. The BCR-three sequence leaching procedure of FT confirmed that all metals were transformed into more stable forms (residue and oxidizable forms) than were found that in NS. The potential ecological risk index indicated that the overall risks caused by heavy metals decreased significantly from 6627.59 and 7229.67 (very serious risk) in NS₁ and NS₂, respectively, to 80.26 and 76.27 (low risk) in FT₁ and FT₂, respectively. According to the risk assessment code, none of the heavy metals in FT posed significant risk to the natural environment except Zn (with low risk). In general, the risk of heavy metals in FT had been well controlled.     

Application of HYDRUS 1D model for assessment of phenol–soil adsorption dynamics

Laboratory-scale batch, vertical, and horizontal column experiments were conducted to investigate the attenuative capacity of a fine-grained clayey soil of local origin in the surrounding of a steel plant wastewater discharge site in West Bengal, India, for removal of phenol. Linear, Langmuir, and Freundlich isotherm plots from batch experimental data revealed that Freundlich isotherm model was reasonably fitted (R ²?=?0.94). The breakthrough column experiments were also carried out with different soil bed heights (5, 10, and 15 cm) under uniform flow to study the hydraulic movements of phenol by evaluating time concentration flow behavior using bromide as a tracer. The horizontal migration test was also conducted in the laboratory using adsorptive phenol and nonreactive bromide tracer to explore the movement of solute in a horizontal distance. The hydrodynamic dispersion coefficients (D) in the vertical and horizontal directions in the soil were estimated using nonlinear least-square parameter optimization method in CXTFIT model. In addition, the equilibrium convection dispersion model in HYDRUS 1D was also examined to simulate the fate and transport of phenol in vertical and horizontal directions using Freundlich isotherm constants and estimated hydrodynamic parameters as input in the model. The model efficacy and validation were examined through statistical parameters such as the coefficient of determination (R ²), root mean square error and design of index (d).     

Development and evaluation of air pollution–linked quality of life (AP-QOL) questionnaire: insight from two different cohorts

Environmental Science and Pollution Research - In this study, the air pollution–related quality of life (AP-QOL) questionnaire was carried out in two geographically and economically different...     

Fifteen years of monitoring of POPs in the breast milk, Czech Republic, 1994–2009: trends and factors

Background, aim and scope

The breast milk has been recommended to carry out as a monitoring tool for effectiveness evaluation of the Stockholm Convention on Persistent Organic Pollutants (POPs). Polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloro-ethane (DDT) and its metabolites (DDX), hexachlorbenzene (HCB) and isomers of hexachlocyklohexane (HCHs) have been monitored in the breast milk of nursing mothers in the Czech Republic since 1994 as a part of The Environmental Health Monitoring System. Knowledge about long-term POPs distribution and accumulation in the human body is crucial to understanding uptake, degradation and subsequent effects as well as to conduct risk assessments. The main aim of this study is to evaluate 15-years long-term trends of selected POPs in human milk in the Czech Republic and to elucidate the questionnaire information about the age, parity and social habits, to the final concentrations. This effectiveness evaluation of POPs restriction is quite precisely after 15-years monitoring campaigns.

Materials, methods and results

The human milk samples (4,753 samples) were analysed for a number of chlorinated organic chemicals including PCBs and selected chlorinated pesticides (OCPs, HCB, HCHs, DDX). The relative change of concentration per year for all chemicals was analysed. The remaining percentages of POPs in breast milk in comparison to 1994 are also expressed. Czech population half-lives of POPs in breast milk, derived from either linear or exponential models were computed.

Conclusions and perspectives

The long-term data indicates a continuation of a decreasing trend of POPs concentrations on breast milk. Our study did not confirm lactation and parity as an important outflux resulting in the decrease in concentrations in mothers, which is in the antagonism with most of the studies. The higher BMI was associated with higher amounts of HCB and lower amounts of higher chlorinated PCBs. The results confirm the effectiveness of restrictions of POPs usage in the Czech Republic. This ongoing long-term study is very useful tool for parametric effectiveness evaluation of Stockholm Convention.     

Multiscale analysis of factors affecting food security in China, 1980–2017

Environmental Science and Pollution Research - Food security is an important issue affecting people’s lives and social stability. Clarifying levels of food security and the factors affecting...     

A study on influential factors of high-phosphorus wastewater treated by electrocoagulation–ultrasound

A combined treatment of electrocoagulation and ultrasound was proposed to solve some problems which exist in the phosphorus removal processes in fine chemical industry. The intermittently discharged wastewater has the features of high initial phosphorus concentration and wide initial pH variation. The electrocoagulation–ultrasound effective performance for the removal of phosphorus was investigated. The results obtained from synthetic wastewater showed that the total phosphorus (TP) decreased from 86 to about 0.4 mg/L, and the removal efficiency reached about 99.6 %, when ultrasound was applied to the electrocoagulation cell under the optimum working conditions in 10 min. Comparatively, the TP removal efficiency of electrocoagulation group was 81.3 % and the ultrasound group has almost no change. Therefore, we can conclude that the electrocoagulation and ultrasound synergistic effect can effectively degrade high-phosphorus wastewater. We have discussed the impact of various parameters on the electrocoagulation–ultrasound based on the phosphorus removal efficiency. The results obtained from synthetic wastewater showed that the optimum working pH was found to be 6, allowing the effluent to be met the emission standards without pH adjustment. An increased current enhanced the speed of treatment significance, but higher current (>40 mA/cm²) enhanced ultrasonic cavitation effect causing flocculation ineffective. In addition, it was found that the optimum ultrasonic power was 4 W/cm² and the frequency was 20 kHz. The best ultrasound intervention and ultrasonic irradiation time were processed with electrocoagulation simultaneously. The results indicated that the electrocoagulation–ultrasound could be utilized as an attractive technique for removal of phosphate in the real wastewater.     

Characterization of spent nickel–metal hydride batteries and a preliminary economic evaluation of the recovery processes

Valuable metal materials can be recovered from spent nickel–metal hydride (NiMH) batteries. However, little attention has been paid to the metal compositions of individual components of NiMH batteries, although this is important for the selection of the appropriate recycling process. In this study, NiMH batteries were manually disassembled to identify the components and to characterize the metals in each of these. A preliminary economic analysis was also conducted to evaluate the recovery of valuable metals from spent NiMH batteries using thermal melting versus simple mechanical separation. The results of this study show that metallic components account for more than 60% of battery weight. The contents of Ni, Fe, Co, and rare earth elements (REEs) (i.e., valuable metals of interest for recovery) in a single battery were 17.9%, 15.4%, 4.41%, and 17.3%, respectively. Most of the Fe was in the battery components of the steel cathode collector, cathode cap, and anode metal grid, while Ni (>90%) and Co (>90%) were mainly in the electrode active materials (anode and cathode metal powders). About 1.88 g of REEs (Ce, La, and Y) could be obtained from one spent NiMH battery. The estimated profits from recovering valuable metals from spent NiMH batteries by using thermal melting and mechanical processes are 2,329 and 2,531 USD/ton, respectively, when including a subsidy of 1,710 USD/ton. The findings of this study are very useful for further research related to technical and economic evaluations of the recovery of valuable metals from spent NiMH batteries. Implications: The spent nickel–metal hydride (NiMH) batteries were manually disassembled and their components were identified. The metals account for more than 60% of battery weight, when Ni, Fe, Co, and rare earth elements (REEs) were 17.9%, 15.4%, 4.41%, and 17.3%, respectively, in a single battery. The estimated profits of recovering valuable metals from NiMH batteries by using thermal melting and mechanical processing are 2,329 and 2,531 USD/ton, respectively, when including a subsidy of 1,710 USD/ton. These findings are very useful to develop or select the recovery methods of valuable metals from spent NiMH batteries.     

A model for NOx–O3–terpene chemistry in chamber measurements of plant gas exchange

Cuvette measurements are a tool to analyse CO₂ exchange, transipiration and deposition/emission of different trace gases by plants. To verify these experimental methods and to use them efficiently we have developed a numerical model with atmospheric chemical reactions. The model includes reactions between 54 different chemical species in the gas phase. Using the model we are able to determine optimal size/flow rate ratios and cuvette cycles (closure times) from an experimental point of view. Using the cuvette model with atmospheric chemistry more accurate estimates for emissions/deposition rates of different species can be found. Some chemical reactions are significant, e.g. for NO and terpenes, as regards the analysis and interpretation of measured concentrations. With slower flow rates through a cuvette the significance of reactions is more pronounced. However, there are some species like ozone, where stomatal deposition is a dominant phenomenon and chemistry plays a minor role.     

Towards the analysis of urban livability in China: spatial–temporal changes,regional types,and influencing factors

Environmental Science and Pollution Research - The increasing drift of urbanization and its impact on urban human settlements are of major concern for China cities. Therefore, demystifying the...     

Bio-efficacy evaluation of nanoformulations of β-cyfluthrin against Callosobruchus maculatus (Coleoptera: Bruchidae)

In the present investigation, bioefficacy of developed β-cyfluthrin formulations, utilizing laboratory synthesized poly(ethylene glycols) based amphiphilic copolymers, were evaluated against Callosobruchus maculatus (Coleoptera: Bruchidae). The bioefficacy data indicated that the formulations developed by utilizing polymers having PEG - 1500 (3c) and PEG - 2000 (3d) as the hydrophilic segment showed greater efficacy after 14 days as evident from EC(50) values (2.2 and 1.58 mg L(-1) respectively). Also, release from the commercial SC formulation was faster than developed formulations as the commercial formulation had the lowest EC(50) value on the first day (0.51 mg L(-1)). The mean EC(50) of the commercial formulation against C. maculatus was quite high as compared to those of developed formulations. The results suggest that depending upon the polymer matrix used, the application rate of β-cyfluthrin can be optimized to achieve insect control at the desired level and period. The results described in this paper are promising and provide a comparison of developed formulations with the commercial one showing an earlier degradation of β-cyfluthrin in the latter and relatively prolonged activity in the former.     

Bio-efficacy evaluation of nanoformulations of β-cyfluthrin against Callosobruchus maculatus (Coleoptera: Bruchidae)

In the present investigation, bioefficacy of developed β-cyfluthrin formulations, utilizing laboratory synthesized poly(ethylene glycols) based amphiphilic copolymers, were evaluated against Callosobruchus maculatus (Coleoptera: Bruchidae). The bioefficacy data indicated that the formulations developed by utilizing polymers having PEG – 1500 (3c) and PEG – 2000 (3d) as the hydrophilic segment showed greater efficacy after 14 days as evident from EC₅₀ values (2.2 and 1.58 mg L^?1 respectively). Also, release from the commercial SC formulation was faster than developed formulations as the commercial formulation had the lowest EC₅₀ value on the first day (0.51 mg L^?1). The mean EC₅₀ of the commercial formulation against C. maculatus was quite high as compared to those of developed formulations. The results suggest that depending upon the polymer matrix used, the application rate of β-cyfluthrin can be optimized to achieve insect control at the desired level and period. The results described in this paper are promising and provide a comparison of developed formulations with the commercial one showing an earlier degradation of β-cyfluthrin in the latter and relatively prolonged activity in the former.     

Impacts of hydrologic variations on chemical weathering and solute sources in the Min River basin,Himalayan–Tibetan region

Environmental Science and Pollution Research - Feedback between hydrologic variations and chemical weathering is thought to play a crucial role in modulating global carbon cycling. The mechanisms...     

Nontargeted evaluation of the fate of steroids during wastewater treatment by comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry

Emerging organic contaminants in wastewater are usually analyzed by targeted approaches, and especially estrogens have been the focus of environmental research due to their high hormonal activity. The selection of specific target compounds means, however, that most of the sample components, including transformation products and potential new contaminants, are neglected. In this study, the fate of steroidal compounds in wastewater treatment processes was evaluated by a nontargeted approach based on comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry. The potential of the nontargeted approach to generate comprehensive information about sample constituents was demonstrated with use of statistical tools. Transformation pathways of the tentatively identified compounds with steroidal four-ring structure were proposed. The purification efficiency of the wastewater treatment plants was studied, and the distribution of the compounds of interest in the suspended solids, effluent water, and sludge was measured. The results showed that, owing to strong adsorption of hydrophobic compounds onto the solid matter, the steroids were mostly bound to the suspended solids of the effluent water and the sewage sludge at the end of the treatment process. The most abundant steroid class was androstanes in the aqueous phase and cholestanes in the solid phase. 17β-estradiol was the most abundant estrogen in the aqueous phase, but it was only detected in the influent samples indicating efficient removal during the treatment process. In the sludge samples, however, high concentrations of an oxidation product of 17β-estradiol, estrone, were measured.     

The key role of hydrophobicity in the determination of pharmaceuticals by liquid chromatography–electrospray ionization-mass spectrometry under the interference of natural organic matter

Environmental Science and Pollution Research - The determination of trace-level pharmaceuticals in water is generally performed using liquid chromatography combined with mass spectrometry, which is...     

Preparation and evaluation of humic acid–based composite dust suppressant for coal storage and transportation

Environmental Science and Pollution Research - To mitigate environmental pollution caused by the escape of dust during coal storage and transportation, humic acid (HA) and grafted acrylamide (AM)...