The petroleum production has been raised sharply over the past decades, whereas the petroleum exploitation has also caused serious environmental contamination. A pot experiment has been conducted to monitor the dynamic response of antioxidant defense system and the growth reaction of Amorpha fruticosa seedlings to soil petroleum contamination. The results show that (1) in 5 g kg⁻¹ contaminated soil, A. fruticosa removes reactive oxygen species (ROS) by increasing the activities of antioxidant enzymes (glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT)), while in 10–15 g kg⁻¹ long-term contaminated soil, A. fruticosa removes ROS by the cooperation of antioxidant enzymes and antioxidants (SOD, CAT, ascorbate peroxidase (APX), GR, ascorbic acid (AsA), glutathione (GSH), and proline (Pro)). In long-term 20 g kg⁻¹ contaminated soil, the defense ability of APX and AsA decreases sharply, and A. fruticosa removes the ROS by the synergistic effect of antioxidant enzymes (SOD and CAT) and antioxidants (GSH and Pro). Only in 20 g kg⁻¹ long-term petroleum contamination caused significant (P < 0.05) increase in H₂O₂ content in seedlings. (2) SOD, CAT, GR, GSH, and Pro exhibit increases in long-term severely contaminated soil, and these enzymes and antioxidants are the most important defender of A. fruticosa to ROS accumulation caused by petroleum contamination. (3) The growth of A. fruticosa seedlings is less affected in 5 g kg⁻¹ petroleum-contaminated soil, while it significantly decreases in 10, 15, and 20 g kg⁻¹ petroleum-contaminated soils (P < 0.05). (4) Considering comprehensively the response of antioxidant defense system and the growth reaction of seedlings to petroleum contamination, A. fruticosa could be utilized for phytoremediation in ≤15 g kg⁻¹ contaminated soil.

This study evaluated the possibility of improving the macronutrient status of Cd-stressed white mustard ‘Rota’ using intensive S nutrition. Three S-SO₄ (2, 6, 9 mM S) and four CdCl₂ doses (0, 0.0002, 0.02, 0.04 mM Cd) in the Hoagland’s nutrient solution were conducted for 14 days. High S supply (6 or 9 mM) appears, to some extent, to affect positively the macronutrient status of Cd-stressed mustard. It increased roots and shoots contents of K and S, without significant changes in P content. Simultaneously, Mg content in shoots and roots remained stable, but Mg bioaccumulation was elevated. Shoot Ca content at the lowest and medium Cd dose decreased, whilst was unaffected at the highest Cd treatment. Intensive S nutrition of Cd-stressed mustard increased root N content and accumulation at the highest Cd concentration, but the N content dropped in above-ground parts. The bioaccumulation of remained macronutrients in general was substantially elevated together with enhanced Cd accumulation. Thus, the intensive S nutrition can enhance mustard tolerance to Cd stress by improvement macronutrients relations in plants, and S supplementation may be recommended for mustard cultivation on the Cd-contaminated areas.

The effects of soil micro-particles and micro-pores on the release of total petroleum hydrocarbons (TPH) were investigated using long-term weathered, TPH-contaminated soil samples. The TPH concentrations were analyzed using various extraction schemes (i.e., total extraction, weak extraction, solvent extraction with or without ultrasound). The particle size distribution (<2 mm, 0.063–2 mm, <0.063 mm), micro-pore volume (<0.38 mm), and TPH fraction (C8–14, C16–28, C30–40) of selected samples were also determined to better understand the factors controlling TPH release from contaminated soils. TPH concentrations varied greatly among different fractions of each soil sample, but were highest in the micro-fraction (<0.063 mm) of each sample. In weathered soil samples, TPH was not only weakly or strongly adsorbed on soil particles, but also trapped in soil micro-pores. Moreover, heavier fractions of TPH were released slowly and lesser extent from contaminated soils. Results showed that the solvent extraction method with and without ultrasound could be used to assess relative binding strength of TPH to contaminated soils. These findings imply that to achieve a remediation goal, some contaminated soils require only relatively mild extraction with solvent, but soils with TPH trapped in micro-pores require physical destruction along with chemical extraction.

The bulk deposition of both PAHs and metals is a significant, mounting issue for the urban ecological environment. However, studies generally performed on these pollutants have focused on the regions surrounding a pollution source; thus, it most likely overestimated pollutants in the cities. Therefore, 72 atmospheric bulk deposition samples were collected from six sites located along a transect from the suburbs to the city center in Shanghai over a 1-year period (February 1, 2012 to January 31, 2013). The seasonal variation, spatial distribution, and sources of multiple metals (Al, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, As, Cd, Pb, K, Na, and Mg) and 16 polycyclic aromatic hydrocarbon (PAH) compounds were determined. The results indicated that the annual average rate of dust deposition in Shanghai was 43,100 ± 54,800 mg/m²/year. There were significant or high enrichments of Cu, Zn, Cd, and Pb, and higher depositional fluxes were observed for Zn, Pb, and Cd in the Huangpu district and for Cu in the Minhang district. The deposition fluxes of the PAHs exhibited the following order: urban fringe zone > city center > rural zone (background site). However, unlike in northern Chinese cities, the high-molecular-weight PAHs accounted for most of the PAHs. Furthermore, there were higher depositional fluxes of PAHs in March, July, and October. Overall, the factors influencing urban air quality may include construction, fossil fuel combustion, the abrasion of tires and brake linings (directly related to traffic), the corrosion of galvanized protection barriers, and increasing population density.

The mass spectrometric analysis of the impact of sulfur dioxide and dust emission on carbon and oxygen stable isotopic compositions of glucose hydrolysed from α-cellulose samples extracted from Scots pine growing in the vicinity of “Huta Katowice” steelworks was the main aim of this study. The annual rings covered the time span from 1975 to 2012 AD. The relationships between climatic conditions, sulfur dioxide, and industrial dust emission and oxygen and carbon isotopic compositions were analyzed using correlation function methods. This study shows the first analysis of carbon and oxygen stable isotopes in glucose as the bio-indicators of CO₂, sulfur dioxide, and industrial dust emission. The anticoincidence trend of δ¹⁸O and δ¹³C and dust and sulfur dioxide confirms that the decreases of dust and sulfur dioxide industrial emission increase δ¹⁸O and δ¹³C values in glucose.

In earlier studies in the existing literature, concentration balance in the feeding solution has never been considered as an influencing factor when the studies were carried out under several feeding conditions to examine effects of different carbon sources on the enhanced biological phosphorus removal (EBPR) process. For a better understanding of a stable operation of an EBPR reactor, it is thought that effects of the concentration balance need to be combined and evaluated with effects of the type of carbon sources in EBPR studies. Therefore, this study was aimed at determining the effect of concentration balance on the performance stability and the phosphorus and glycogen dynamics of a sequencing batch reactor (SBR). In this study, the SBR operation was divided into two main stages. In the first stage, two different ratios of the total concentration of monovalent (M) to divalent (D) cations (in milliequivalent per liter, meq/L) (7.6 and 1.5, 30 days of operation for each) was applied in the feeding solution to investigate the effect of the concentration balance on the performance stability of the SBR. During this stage, sodium acetate was used as the sole carbon source. To investigate the effect of the type of carbon source on the EBPR process under the condition of constant M/D ratio, sodium acetate was used as the sole carbon source during the first half of the reactor operation of 120 days, and, then, the carbon source was abruptly switched to glucose in the second stage.

Difficulties encountered in estimating the biodegradation of poorly water-soluble substances are often linked to their limited bioavailability to microorganisms. Many original bioavailability improvement methods (BIMs) have been described, but no global approach was proposed for a standardized comparison of these. The latter would be a valuable tool as part of a wider strategy for evaluating poorly water-soluble substances. The purpose of this study was to define an evaluation strategy following the assessment of different BIMs adapted to poorly water-soluble substances with ready biodegradability tests. The study was performed with two poorly water-soluble chemicals—a solid, anthraquinone, and a liquid, isodecyl neopentanoate—and five BIMs were compared to the direct addition method (reference method), i.e., (i) ultrasonic dispersion, (ii) adsorption onto silica gel, (iii) dispersion using an emulsifier, (iv) dispersion with silicone oil, and (v) dispersion with emulsifier and silicone oil. A two-phase evaluation strategy of solid and liquid chemicals was developed involving the selection of the most relevant BIMs for enhancing the biodegradability of tested substances. A description is given of a BIM classification ratio (R BIM), which enables a comparison to be made between the different test chemical sample preparation methods used in the various tests. Thereby, using this comparison, the BIMs giving rise to the greatest biodegradability were ultrasonic dispersion and dispersion with silicone oil or with silicone oil and emulsifier for the tested solid chemical, adsorption onto silica gel, and ultrasonic dispersion for the liquid one.

We conducted multiday continuous monitoring of indoor and outdoor particulate matter (PM) in classrooms with fan-assisted natural ventilation (NV) at five primary schools in Singapore. We monitored size-resolved number concentration of PM with diameter 0.3–10 μm at all schools and alveolar deposited surface area concentrations of PM with diameter 0.01–1.0 μm (SA₀.₀₁–₁.₀) at two schools. Results show that, during the monitoring period, schools closer to expressways and in the downtown area had 2–3 times higher outdoor PM₀.₃–₁.₀ number concentrations than schools located in suburban areas. Average indoor SA₀.₀₁–₁.₀ was 115–118 μm² cm⁻³ during periods of occupancy and 72–87 μm² cm⁻³ during unoccupied periods. There were close indoor and outdoor correlations for fine PM during both occupied and unoccupied periods (Pearson’s r = 0.84–1.0) while the correlations for coarse PM were weak during the occupied periods (r = 0.13–0.74). Across all the schools, the size-resolved indoor/outdoor PM ratios (I/O ratios) were 0.81 to 1.58 and 0.61 to 0.95 during occupied and unoccupied periods, respectively, and average infiltration factors were 0.64 to 0.94. Average PM net emission rates, calculated during periods of occupancy in the classrooms, were lower than or in the lower range of emission rates reported in the literature. This study also reveals that indoor fine and submicron PM predominantly come from outdoor sources, while indoor sources associated with occupancy may be important for coarse PM even when the classrooms have high air exchange rates.

This outdoor research investigated the variations in soil ammonium (NH₃-N), nitrite (NO₂-N), nitrate (NO₃-N), total organic nitrogen (TON), and microbial biomass carbon (MBC) in bioretention tanks. Two biretention tanks (tank 1#: The depth of 0–20 cm was vacant aquifer layer; 20–90 cm, filled with the planting soil; 90–105 cm, filled with gravel. tank 3#: 0–20 cm was aquifer layer, 20–50 cm, filled with the planting soil; 50–90 cm, filled with blast furnace slag and sand; 90–105 cm, filled with gravel) were used with simulated rainwater discharge experiments to obtain soil samples at intervals of 1 h before the inflow and 24 h after the end of inflow. Results indicate that soil nitrogen (N) and MBC in two bioretention tanks were mainly captured at 10∼30 cm depth in soil; the content of soil NH₃-N exhibited a trend of initial decline but increase with time; the content of NO₂-N varied from 0.011 to 0.024 g/kg, and the change regularity was similar with the NH₃-N; different from the NH₃-N and NO₂-N, soil NO₃-N exhibited a trend of declining; while TON exhibited a trend of declining after slightly increase. Meanwhile, the content of NH₃-N and NO₃-N at 50 cm depth in tank 1# was slight lower than those at 10 and 30 cm; conversely, the discrepancy at the different depths in tank 3# was small. The contents of soil NH₃-N and NO₂-N before inflow were less than those after inflow, but it was adverse for NO₃-N. The NO₃-N leaching in bioretention system is a main reason for poor N removal in runoff. The content of MBC ranged from 1.055 to 1.847 g/kg and exhibited a trend of decline after increase. Furthermore, the content of MBC and TN has good linear correlation in bioretention tanks (R ² > 0.8), but it has general performance with TP (R ² > 0.5). The immobilization of NH₃-N, NO₂-N, and NO₃-N at the planting soil layer in tank 1# was greater than that in tank 3#. The N interception differences in the two tanks resulted from different infiltration rates of their underlying fillers.

Psychiatric pharmaceuticals, such as anxiolytics, sedatives, hypnotics and antidepressors, are among the most prescribed active substances in the world. The occurrence of these compounds in the environment, as well as the adverse effects they can have on non-target organisms, justifies the growing concern about these emerging environmental pollutants. This study aims to analyse the effects of six psychotropic drugs, valproate, cyamemazine, citalopram, sertraline, fluoxetine and oxazepam, on the survival and locomotion of Japanese medaka Oryzias latipes larvae. Newly hatched Japanese medaka were exposed to individual compounds for 72 h, at concentrations ranging from 10 μg L⁻¹ to 10 mg L⁻¹. Lethal concentrations 50 % (LC₅₀) were estimated at 840, 841 and 9,136 μg L⁻¹ for fluoxetine, sertraline and citalopram, respectively, while other compounds did not induce any significant increase in mortality. Analysis of the swimming behaviour of larvae, including total distance moved, mobility and location, provided an estimated lowest observed effect concentration (LOEC) of 10 μg L⁻¹ for citalopram and oxazepam, 12.2 μg L⁻¹ for cyamemazine, 100 μg L⁻¹ for fluoxetine, 1,000 μg L⁻¹ for sertraline and >10,000 μg L⁻¹ for valproate. Realistic environmental mixture of the six psychotropic compounds induced disruption of larval locomotor behaviour at concentrations about 10- to 100-fold greater than environmental concentrations.