Acceleration of environmental degradation in recent years highlights the environmental quality as an indication of welfare and increases the number of studies conducted within this framework. Also, economic decision-making units have been doing various spending in order to maintain/increase environmental quality. In this context, the aim of this study is to examine the effect of environmental expenditures made by public sector on ecological deficit as a representative of the environmental quality for 9 coordinated market economies in Europe from 1995 to 2014. According to the findings acquired in the research, a cointegration relationship has been found between variables. It has been detected within the frame of panel ARDL analysis that total public expenditures increase the ecological deficit while environmental expenditures decrease it. In other words, scale effect of public expenditures affects the environmental quality negatively but its composition effect which will take place in favour of environmental expenditures has a positive effect. Thus, instead of the size of public expenditures, focusing on how the content of public expenditures of policy makers is formed in a way highlighting the environmental expenditures can boost welfare over environmental quality.

The extensive use of anticoagulant rodenticides (ARs) results in widespread unintentional exposure of non-target rodents and secondary poisoning of predators despite regulatory measures to manage and reduce exposure risk. To elucidate on the potential vectoring of ARs into surrounding habitats by non-target small mammals, we determined bromadiolone prevalence and concentrations in rodents and shrews near bait boxes during an experimental application of the poison for 2 weeks. Overall, bromadiolone was detected in 12.6% of all small rodents and insectivores. Less than 20 m from bait boxes, 48.6% of small mammals had detectable levels of bromadiolone. The prevalence of poisoned small mammals decreased with distance to bait boxes, but bromadiolone concentration in the rodenticide positive individuals did not. Poisoned small mammals were trapped up to 89 m from bait boxes. Bromadiolone concentrations in yellow-necked mice (Apodemus flavicollis) were higher than concentrations in bank vole (Myodes glareolus), field vole (Microtus agrestis), harvest mouse (Micromys minutus), and common shrew (Sorex araneus). Our field trials documents that chemical rodent control results in widespread exposure of non-target small mammals and that AR poisoned small mammals disperse away from bating sites to become available to predators and scavengers in large areas of the landscape. The results suggest that the unintentional secondary exposure of predators and scavengers is an unavoidable consequence of chemical rodent control outside buildings and infrastructures.

The thickening performance of CO₂ fracturing fluid was poor because of the low apparent viscosity. In this paper, the thickening performance of a modified silicone on liquid CO₂ is measured, and a rheology was investigated according to the consistency coefficient K and rheological index n. Meanwhile, a reservoir model was established to evaluate the fracturing property. Results showed that the modified silicone contributes to improve the apparent viscosity of liquid CO₂ and decrease the rheology of liquid CO₂. With the thickener content or pressure increase, the apparent viscosity of liquid CO₂ increases, and the rheological index n decreased obviously. A reduced apparent viscosity is shown as the flow rate or temperature rises, but the rheology increased gradually. The fracturing simulation herein shows that thickened CO₂ fracturing fluid could improve obviously the fracture property. This modified thickener possesses the potential as a thickener and could be a reliable alternative to the thickener in CO₂ fracturing technology, and the large contact angle improved the backflow property of this CO₂ thickener from rock surfaces. The development of CO₂ fracturing technology provides basic data for the improvement of greenhouse effect and clean mining of energy.

In the present study, NH₄Cl-modified activated carbon was synthesized from rice husk and used as an adsorbent for removal of hinosan from underground waters. The effect of some effective parameters on the adsorption of hinosan on the rice husk NH₄Cl-modified activated carbon (RHNAC) like pH, adsorbent dose, contact time, and temperature was evaluated in batch mode and the optimum conditions were determined. Kinetic of adsorption was studied by Langmuir and Freundlich’s models. The equilibrium data were well fitted to the Langmuir isotherm model, and the maximum adsorption capacity of hinosan on RHNAC based on the Langmuir isotherm model was 81.366 mg g⁻¹. The experimental adsorption data had the best fitness with the pseudo-second-order kinetic model. The applicability of the prepared adsorbent (RHNAC) was compared with other activated carbons (ZnCl₂-modified activated carbon was prepared from rice husk and industrial activated carbon). The obtained results which were calculated from the selected adsorbents showed more desirability for RHNAC as an adsorbent. So, RHNAC could be introduced as an effective and cost-effective adsorbent for removal of hinosan from underground waters. Graphical abstract

In the present study, electrospun nanofiber membranes (ENMs) of polyacrylonitrile (PAN) were modified by dispersing α-Fe₂O₃ nanoparticles, synthesized using a thermal solvent process, in a PAN solution. The morphology and physiochemical properties of the prepared ENMs and the α-Fe₂O₃ were characterized using FESEM, EDX, BET, XRD, FTIR, porosity, and contact angle measurement. XPS was used to investigate the interaction of ENM with arsenate (As(V)) during the adsorption. Moreover, the effect of pH, the equilibrium isotherm, and the kinetics were investigated in batch experiments. The Langmuir isotherm best correlated the experimental results, indicating monolayer adsorption on ENMs, and the kinetics was best fitted, R² > 0.99, by the pseudo-second-order model. In addition, the effects of certain conditions on the filtration performance were examined, such as feed concentration and transmembrane pressure (TMP). By passing sodium hydroxide (0.1 M) for 20 min, the membrane was regenerated. The increase in TMP, along with the presence of co-ions including chloride, nitrate, and sulfate, had negative impacts on the removal of As(V). The results show that the modified ENMs with α-Fe₂O₃ nanoparticles are applicable for As(V) ion removal and possibly for eliminating other heavy metals from aqueous media.

Rice is considered the most main food in Iranian diet. Its chemical contamination with heavy metals can lead to adverse effects to human health. In the present study, 60 imported rice samples from 20 different brands were collected and examined in terms of lead and arsenic levels in Tehran. Besides, point estimation and uncertainty analysis were used to determine the additional risk of carcinogenicity and non-carcinogenicity in raw and as-consumed rice. The results showed that the means of lead and arsenic (mg/kg fresh weight) in raw sampled rice were 0.0352 ± 0.0398 and 0.106 ± 0.049, respectively, and they were 0.0226 ± 0.0360 and 0.0689 ± 0.046 in as-consumed rice, respectively. Additionally, lead and arsenic amounts were 5% and 15% higher than the value set by Institute of Standards and Industrial Research of Iran respectively, while assessment of the non-carcinogenicity risk of lead and arsenic in point estimation and uncertainty analysis showed the hazard quotient and hazard index values were less than 1 and in safe ranges in both raw and as-consumed rice and were not considered a threat to the public health. The additional risk of arsenic carcinogenicity in point estimation and uncertainty analysis in raw and as-consumed rice samples found higher than the 1E-06 EPA’s acceptable level of risk. So, these results could be applicable and encourage researchers to perform more detailed studies with more samples for considering by food authorities.

The present work is dedicated to the experimental analysis on the influence of fuel-borne additives on ternary fuel blend operated in a single cylinder DI diesel engine. Alumina (Al₂O₃) nanoparticles were chosen as fuel additives at dosing levels of 10, 20, and 30 ppm, respectively, and the ternary fuel (TF) is prepared by blending 70% diesel, 20% Jatropha biodiesel, and 10% ethanol. Performance characteristics like brake thermal efficiency (BTE) and brake-specific energy consumption (BSEC) and emission characteristics like HC, CO, NOx, and smoke along with combustion characteristics like cylinder pressure, HRR (heat release rate), and CHRR (cumulative heat release rate) were considered for analysis. Based on experimentation, it is observed that TF blended with 20 ppm alumina nanoadditive (TF20) resulted in higher BTE and lowered BSEC by 7.8 and 4.93% and lowered HC, CO, NOx, and smoke emissions by 5.69, 11.24, 9.39, and 6.48% in comparison with TF. Moreover, TF20 resulted in higher cylinder pressure, HRR, and CHRR of about 72.67 bar, 76.22 J/°CA, and 1171.1 J, respectively, which are higher than those of diesel and TF. Hence, it is concluded that the addition of 20 ppm alumina nanoadditive in TF can enhance the engine performance and combustion as well as lower the exhaust pollutants simultaneously.

Water fountains are usually present in the urban public places and often draw the attention of citizens and tourists. Their water is often, in various ways, used by adults and children, but water from fountains is not usually a subject of researchers’ interest. This paper describes the analytical procedure and the results of the multi-elemental characterisation of the waters from the selected public water fountains in the city of Zagreb, Republic of Croatia. Twenty-eight chemical elements (Al, As, B, Ba, Be, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, P, Pb, S, Sb, Se, Sr, Ti, Tl, V, Zn and Ca, K, Mg and Na) were quantified by means of ICP-AES technique. In addition to the multi-elemental analysis, determination of pH values was performed too. Pearson’s correlation coefficients suggest that Al, Cu, Fe, Mn and Pb originate from the plumbing system and their leaching is strongly negatively correlated with the pH values of the tested samples. On the other hand, alkali and alkaline-earth metals as well as Mo, Ti, Zn and B, P and S are most probably of a natural origin in the water samples tested in this study. The results lead to the conclusions that (i) trace and major element content in squirt of a monumental water fountain is analogous to their content in water of the same origin and (ii) a pool of a fountain which is made of a high-quality stone, in the context of the herein performed testings, generally does not affect the quality of water which is contained in it.

Ethidium bromide (EtBr) is widely used as DNA-staining dyes for the detection of nucleic acids in laboratories and known to be powerful mutagens and carcinogens. In the present paper, the removal of EtBr from aqueous solutions in a batch system using DNA-loaded Fe₃O₄ nanoparticles as a simple and efficient method was investigated. DNA was covalently loaded on the surface of Fe₃O₄ magnetic nanoparticles, which was confirmed by FT-IR analysis and zeta potential measurements. The morphology and crystal structure were characterized by SEM, TEM, and XRD. The influence factors on the removal efficiency such as initial EtBr concentration, contact time, adsorbent dose, pH, and temperature were also studied. The removal process of EtBr can be completed quickly within 1 min. The removal efficiency was more than 99% while the EtBr concentration was routinely used (0.5 mg L⁻¹) in biology laboratories and the dosages of nanoparticles were 1 g L⁻¹. For the different EtBr concentrations from 0.5 to 10 mg L⁻¹ in aqueous solution, the goal of optimized removal was achieved by adjusting the dosage of DNA-loaded Fe₃O₄ nanoparticles. The optimum pH was around 7 and the operational temperature from 4 to 35 °C was appropriate. Kinetic studies confirmed that the adsorption followed second-order reaction kinetics. Thermodynamic data revealed that the process was spontaneous and exothermic. The adsorption of EtBr on DNA-loaded Fe₃O₄ nanoparticles fitted well with the Freundlich isotherm model. These results indicated that DNA-loaded Fe₃O₄ nanoparticles are a promising adsorbent for highly efficient removal of EtBr from aqueous solution in practice.

Phosphorus (P), an essential element for living cells, is present in different soluble and adsorbed chemical forms found in soil, sediment, and water. Most species are generally immobile and easily adsorbed onto soil particles. However, P is a major concern owing to its serious environmental effects (e.g., eutrophication, scale formation) when found in excess in natural or engineered environments. Commercial chemicals, fertilizers, sewage effluent, animal manure, and agricultural waste are the major sources of P pollution. But there is limited P resources worldwide. Therefore, the fate, effects, and transport of P in association with its removal, treatment, and recycling in natural and engineered systems are important. P removal and recycling technologies utilize different types of physical, biological, and chemical processes. Moreover, P minerals (struvite, vivianite, etc.) can precipitate and form scales in drinking water and wastewater systems. Hence, P minerals (e.g., struvite, vivianite etc.) are problems when left uncontrolled and unmonitored although their recovery is beneficial (e.g., slow release fertilizers, sustainable P sources, soil enhancers). Sources like wastewater, human waste, waste nutrient solution, etc. can be used for P recycling. This review paper extensively summarizes the importance and distribution of P in different environmental compartments, the effects of P in natural and engineered systems, P removal mechanisms through treatment, and recycling technologies specially focusing on various types of phosphate mineral precipitation. In particular, the factors controlling mineral (e.g., struvite and vivianite) precipitation in natural and engineered systems are also discussed.