Because of its low concentration, its unique physico-chemical properties and the analytical difficulties associated with its measurement, the determination of mercury species in solids is not an easy task. Thermal desorption (HgTPD) is an attractive option for the identification of mercury species in solids due to its simplicity and accessibility. However, there are still issues that need to be solved for it to reach its full potential. One such issue is the availability of reference materials that will reproduce real mercury associations. The novelty of this study is the use of six uncommon mercury minerals, taken from around the world, and a sphalerite sample to expand the data base of reference materials for mercury speciation by thermal desorption at programmed temperature. In addition, by using such materials, a number of matrix effects can be ascertained. Different mercury associations were identified depending on the temperature of desorption, thereby validating the thermal desorption as a reliable technique for mercury speciation in solid samples and as a consequence improving the knowledge of the geochemistry of mercury in the environment.

To investigate the characteristics and formation mechanisms of haze pollution in the autumn season in the Sichuan Basin, hourly concentrations of water-soluble inorganic ions in PM₂.₅ (Na⁺, K ⁺, NH₄⁺, Mg²⁺, Ca²⁺, Cl⁻, NO₃⁻, and SO₄²⁻) and major gaseous precursors (HCl, NH₃, SO₂, HONO, and HNO₃) were measured by a gas and aerosol collector combined with ion chromatography (GAC-IC) from September to November 2017 at an urban site in Chengdu. The average mass concentration of total water-soluble ions was 36.9 ± 29.4 μg m⁻³, accounting for 62.8% of PM₂.₅ mass. Nitrate was the most abundant ion, comprising 41.2% of the total ions, followed by sulfate (27.1%) and ammonium (18.1%), indicating the important contribution of motor vehicle emissions to PM₂.₅ in Chengdu. Secondary formation of inorganic ions and biomass burning emissions played a vital role in the haze pollution processes. The formation of nitrate aerosol was particularly dominant and exhibited the most substantial increase during haze processes. It was likely to be produced primarily through homogeneous reactions, whereas heterogeneous reactions dominated sulfate formation. Additionally, distinct differences in diurnal patterns of secondary inorganic ions between clean days and polluted days were observed, reflecting different formation characteristics under polluted conditions. Due to a large increase of acidic aerosols, most particles collected on polluted days were acidic, and ammonium in most samples existed mainly as NH₄HSO₄ and NH₄NO₃. Furthermore, backward-trajectory cluster analysis revealed that air masses originating from the northeast of Chengdu prevailed in the autumn season, and haze pollution was dominated mainly by short-distance transport within the Sichuan Basin.

The lignin-based carbon fibers were prepared by electrospinning followed by stabilization, carbonization, and activation (i.e., steam activation, one-step KOH activation, and metal activation). The effect of carbonization temperature on prepared carbon fibers (CFs) was investigated. As a result, 800 °C is the most suitable carbonization temperature because the prepared carbon fibers possess greater specific surface area and pore volume. With the help of various characterization methods, the structural characteristics of the activated carbon fibers (ACFs) prepared by the three activation methods and the adsorption performance of toluene were compared. It was observed that the activated carbon fibers prepared by KOH one-step activation method (ACFK) exhibited higher specific surface area (1147.16 m²/g) and greater toluene adsorption (463 mg/g). Particularly, abundant microporous structures and surface functional groups play a vital role in the adsorption process. Further, the adsorption performance of toluene onto ACFK was further investigated in a gas-phase dynamic adsorption system and the results showed that ACFK has great potential application in adsorption of volatile organic compounds.

Nonrenewable fossil fuels show increased demand and with fossil fuels at a rapid depleting stage, there seems to be an increase in requirement for alternative fuels too. Biofuels and blended fossil fuels are one of a kind. Nonedible jatropha (Jatropha curcas) oil-based methyl ester was produced and mixed with ethanol and blended with conventional diesel in various compositions. Jatropha biodiesel is used because of its great blending capacity with diesel. Sodium hydroxide is used as a catalyst which allows miscibility between ethanol and diesel. In present epoch, the paucity of fossil fuels and its adverse impact have driven researchers to focus on alternative fuels. Biodiesel is one of the most favorable and promising alternatives in the application of automobiles, boilers, gas turbines, etc. This study targets at finding the engine performance and emission characteristics under various load conditions on Kirloskar single-cylinder VCR research engine by blending both jatropha biodiesel and ethanol with base diesel at various compositions. Both jatropha biodiesel and ethanol have high calorific value which is a most important factor for engine power production. The performance analysis showed that the biodiesel blend of 98% diesel with 1.5% jatropha biodiesel and 0.5% (D98J1.5E0.5) of ethanol had a significant improvement in the engine performance than the conventional diesel.

A comprehensive study was conducted to appraise the concentrations of 30 endocrine disrupting pesticides (EDPs) in soil and vegetable samples collected from Khyber Pakhtunkhwa, Pakistan. The sum of 30 EDPs (Σ₃₀EDPs) ranged from 192 to 2148 μg kg⁻¹ in the collected soils. The selected EDP concentrations exceeded their respective limits in most of the tested soils and showed great variation from site to site. Similarly, high variations in Σ₃₀EDP concentrations were also observed in vegetables with the highest mean concentration in lettuce (28.9 μg kg⁻¹), followed by radish (26.6 μg kg⁻¹), spinach (25.7 μg kg⁻¹), onion (16.2 μg kg⁻¹), turnip (15.6 μg kg⁻¹), and garlic (14.7 μg kg⁻¹). However, EDP levels in all studied vegetables were within FAO/WHO limits. The mean bioconcentration factor values were observed < 1 for all the studied vegetables. The health risk assessment revealed that the incremental lifetime cancer risk (ILCR) of Σ₃₀EDPs associated with vegetable ingestion was below the acceptable risk level (1 × 10⁻⁶), showing no cancer risk to local inhabitants. However, exposure to endocrine disruptor and probable carcinogen heptachlor epoxide poses a potential non-cancer risk (hazard quotient (HQ > 1)) to children through vegetable consumption. The presence of banned EDPs in soils and vegetables of the study area indicates the stability of these legacy chemicals in the environment from over usage in the past or illegal current application for agricultural purposes. Graphical abstract

As China and other developing countries continue to urbanize over the next decades, construction and demolition waste (CDW) management has been becoming a significant challenge for urban sustainability in terms of the environment, economy, and safety. However, accurate estimations or statistics of CDW generation are absent from the official national report in spite of their importance to devise sensible interventions to tackle CDW-related problems. This paper examines and compares the applications of three prevailing methods for estimating CDW, including the weight-per-construction-area method (WAM), buildings’ life span-based method, and weight-per-capita method. Specifically, China has been chosen as the case study. This study implies that the weight-per-construction-area method is more appropriate because of the data availability and accuracy at a city or national level. The results of WAM indicate that a total of 4.1 billion metric tons (Bt) of CDW were generated in China in 2016, mainly from demolition waste (85%). Taking the changes of buildings’ life span into account, a projection analysis reveals that the cumulative CDW generation will be 50 Bt between 2017 and 2040 in China (equal to approximately 38 years cumulative generation of global municipal solid waste). Overall, the findings provide some methodological options for scholars, practitioners, and decision-makers to more accurately estimate the amount of the CDW and to develop a more environmentally sound management strategy.

In this study, the validity of the environmental Kuznets curve (EKC) hypothesis is examined with the newly developed bootstrap autoregressive distributed lag (ARDL) approach by incorporating the effects of trade openness for Turkey from 1969 to 2017. The bootstrap ARDL approach results show that there is a long-run relationship between per capita carbon dioxide (CO₂) emissions, per capita real income, and trade openness in the presence of one structural break. The results of the long-run estimators indicate that the inverted U-shaped EKC hypothesis is valid, and trade openness has an increasing impact on CO₂ emissions. However, Turkey has not yet reached the level of income necessary to reduce pollution. The results of the Fourier Toda–Yamamoto Granger causality test also show that unidirectional causality runs through per capita real income and trade openness to per capita CO₂ emissions. In addition to these findings, it has been determined that the decrease in growth rate and production experienced during the 2001 financial crisis in Turkey reduced environmental pollution in both the short and long runs. Consequently, these results show that the scale and composition effects outweigh for economic growth and trade openness in Turkey.

Drinking water containing environmental endocrine disruptor compounds (EDCs) endangers human health, and researching the purification process of drinking water for the effective removal of EDCs is vitally important. Filtering plays a crucial role in the bio-adsorption of EDCs, but the adsorption mechanism that occurs between the EDCs and filters remains unclear. In this study, a quartz crystal microbalance (QCM) was employed to elucidate the adsorption mechanism because QCM is a label-free method that possesses high selectivity, high stability, and high sensitivity. The results indicated that a pseudo-first-order kinetic model best fits the adsorption process of four different EDCs, which included bisphenol A (BPA), estrone (E1), estradiol (E2), and sulfamethoxazole (SMZ), on silica (quartz sand), a typical filter material surface. The order of the amount of individual EDCs absorbed on the silica surface was qE₂ > qE₁ > qSMZ > qBPA and related to their molecular structure, polarity, and chargeability. As the initial EDC concentration increased, the adsorbed amount of the four EDCs on the silica surface increased; however, the initial concentration had little effect on removal efficiency. The calculated Freundlich exponent (1/n) demonstrated SMZ and BPA showed a greater tendency for adsorption than E1 and E2. The mass response time on the surface of the silica gradually increased as the pH increased (from 5.5 to 8.5), indicating the adsorption rate was inhibited by the increase in pH. The addition of electrolytes shortened the mass response time of EDCs on the QCM chip. The pH and ionic strength produced no significant effects on adsorption because hydrophobicity was the primary contributor to adsorption. This study facilitated a better understanding of the interaction between EDCs and filters in water treatment.

It is claimed that oxidative stress has a prominent role in the mechanism of toxic effects formed by glyphosate-based herbicide (GBH) in living systems. A strong thiol compound, N-acetylcysteine (NAC), has antioxidative and cytoprotective properties. The objective in this subchronic toxicity study was to identify the prophylactic effect of NAC over histopathological changes and oxidative stress induced by GBH in blood, renal, liver, cardiac, and brain tissues. A sum of 28 male Wistar rats were divided into four equal groups, each containing 7 rats. During the study, group I (control group) was supplied with normal rodent bait and tap water ad libitum. The applied agents were 160 mg/kg NAC to group II, 375 mg/kg as equivalent to 1/10 of lethal dose 50% (LD50) of GBH to group III, and 160 mg/kg of NAC and 375 mg/kg of GBH together once per day as oral gavage to group IV for 8 weeks. While GBH decreased the levels of GSH in blood, liver, kidney, and brain tissues, it considerably increased malondialdehyde levels. On the contrary, these parameters happened to improve in the group supplied with NAC. Besides, it was seen that NAC was observed to improve the histopathologic changes in rat tissues induced by GBH. It was concluded that NAC protects oxidative stress and tissue damage induced by GBH in blood and tissue and this prophylactic effect could be attributed to its antioxidant and free radical sweeper character.

Various research works are being undertaken around the world on the subject of thermal efficiency improvisation and emission reduction from diesel engines. This research work analyzes the performance and emission characteristics of a thermal barrier coated diesel engine which used palm biodiesel. The piston and cylinder liners were coated with equal percentages of alumina (Al₂O₃) and yittria-stabilized zirconia (YSZ) powder using plasma spraying coating method. The piston was coated with 100 μm thickness and the two cylinder liners were coated with 150 and 200 μm thicknesses and were used to analyze the performance and emission characteristics. Test results of the thermal barrier coated engine using palm biodiesel were compared with the results derived from the base engine. The tests revealed an increase of 3.8% specific fuel consumption (SFC) as an average when neat palm biodiesel was used in the base engine. Interestingly, the palm biodiesel used in the 150- and 200-μm thick thermal barrier coated engine was responsible for a significant decrease of the SFC by an average of 4.18% and 8.05% respectively. The brake thermal efficiency was found to decrease on an average of 1.02% when tests were run using the neat palm biodiesel in the base engine. But an average proportionate increase of 0.72% and 2.19% was visible when palm biodiesel was used in the tests conducted on the 150- and 200-μm thick thermal barrier coated engine. There was also an understandable brake specific reduction of 0.991 g/kWh carbon monoxide (CO) emission and 0.025 g/kWh unburned hydrocarbon (HC) levels. The nitrogen oxide (NOₓ) emission was observed as 14.06 g/kWh in the 200-μm thick thermal barrier coated engine which was slightly higher when the results were compared with that of the uncoated engine. The novelty of this research investigation is based on the usage of yttrium-stabilized zirconia and alumina thermal barrier coating on the cylinder liner and piston head of engine. This is justified due to the fact that most of the previous investigations undertaken focused on the thermal barrier coating in the piston, valve, and cylinder head alone. The utility factor of the palm biodiesel (B 100) in the low heat rejection engine has also proved to be another significant and novel factor in the present investigation outlined in this paper. This is mainly due to the fact that the ongoing investigations in this realm concentrated only on blends of 20 to 30% of palm biodiesel with diesel fuel in the low heat rejection diesel engine.