Aerosol samples of PM₂.₅ and PM₁₀ were collected every 6 days from March 2012 to February 2013 in Huangshi, a typical industrial city in central China, to investigate the characteristics, relationships, and sources of carbonaceous species. The PM₂.₅ and PM₁₀ samples were analyzed for organic carbon (OC), elemental carbon (EC), char, and soot using the thermal/optical reflectance (TOR) method following the IMPROVE_A protocol. PM₂.₅ and PM₁₀ concentrations ranged from 29.37 to 501.43 μg m⁻³ and from 50.42 to 330.07 μg m⁻³, with average levels of 104.90 and 151.23 μg m⁻³, respectively. The 24-h average level of PM₂.₅ was about three times the US EPA standard of 35 μg m⁻³, and significantly exceeds the Class II National Air Quality Standard of China of 75 μg m⁻³. The seasonal cycles of PM mass and OC concentrations were higher during winter than in summer. EC and char concentrations were generally highest during winter but lowest in spring, while higher soot concentrations occurred in summer. This seasonal variation could be attributed to different seasonal meteorological conditions and changes in source contributions. Strong correlations between OC and EC were found for both PM₂.₅ and PM₁₀ in winter and fall, while char and soot showed a moderate correlation in summer and winter. The average OC/EC ratios were 5.11 and 4.46 for PM₂.₅ and PM₁₀, respectively, with individual OC/EC ratios nearly always exceeding 2.0. Higher char/soot ratios during the four seasons indicated that coal combustion and biomass burning were the major sources for carbonaceous aerosol in Huangshi. Contrary to expectations, secondary organic carbon (SOC) which is estimated using the EC tracer method exhibited spring maximum and summer minimum, suggesting that photochemical activity is not a leading factor in the formation of secondary organic aerosols in the study area. The contribution of SOC to OC concentration for PM₂.₅ and PM₁₀ were 47.33 and 45.38%, respectively, implying that SOC was an important component of OC mass. The serious air pollution in haze-fog episode was strongly correlated with the emissions of pollutants from biomass burning and the meteorological conditions.

In the present study, the electrocatalytic degradation of triazine herbicide metamitron using Ti/PbO₂-CeO₂ composite anode was studied in detail. The effects of the current density, initial metamitron concentration, supporting electrolyte concentration, and initial pH value were investigated and optimized. The results revealed that an electrocatalytic approach possessed a high capability of metamitron removal in aqueous solution. After 120 min, the removal ratio of metamitron could reach 99.0% in 0.2 mol L⁻¹ Na₂SO₄ solution containing 45 mg L⁻¹ metamitron with the current density at 90 mA cm⁻² and pH value at 5.0. The reaction followed the pseudo-first-order kinetics model. HPLC and HPLC-MS were employed to analyze the degradation by-products in the metamitron oxidization process, and the degradation pathway was also proposed, which was divided into two sub-routes according to the different initial attacking positions on metamitron by hydroxyl radicals. Therefore, the electrocatalytic approach was considered as a very promising technology in practical application for herbicide wastewater treatment.

As potassium ferrate(VI) is an important kind of water treatment agent which has a high efficiency in algal removal, its effects on the cell substance are rarely discussed. The changing of the protein and enzyme was analyzed here to deeply understand the oxidation of Fe on the protein in the algae. The result of the research showed the inactivation on growth and the biochemical process of the algal cell were all inhibited by Fe, including the function of the photosynthesis system. During the process, SOD (superoxide dismutase), CAT (catalase), POD (peroxidase), and GST (glutathione S-transferase) played cooperative roles to prevent the injury on the cells from destructive oxidation stress. The lipid peroxidation strengthened the defense system. The damage was intensified with the increase of ferrate concentration.

Biogas reactors are now a common part of wastewater treatment systems. The quality of produced biogas is the result of many factors, mainly the input substrate and microbial composition of the bioreactor. The aim of this research was to evaluate the microbial community of the Modřice biogas reactor together with the possible changes in biogas composition. The key microbial groups and their content in anaerobic digester were identified by sequencing techniques. The most dominant group were sulphate-reducing (45%), followed by methanogenic (19%), acetate (6%) and hydrogen-producing (11%) microorganisms. The remaining microorganisms were identified only to their order (19%). Phylogenetic trees were constructed to show evolutionary relationships of detected microorganisms. The volume of methane in biogas content was 60%, which corresponds with literature data regarding sewage digesters. None of the detected impurities have crossed the safe limits and their volume remained stable during the measurement period. Despite sulphate-reducing bacteria being the dominant group, their produced hydrogen sulphide (H₂S) was detected only in a small quantity (2.43–7.46 ppm) and had no inhibitory effect on the methane production. The mechanism of inhibition by H₂S and the perspective of its biological removal were discussed. Application of phototrophic sulphur bacteria, especially Chlorobiaceae and Chromatiaceae family, and the creation of new photobioreactor systems can be a promising pathway for hydrogen sulphide treatment in biogas plants.

This article studies the price competition and cooperation in a duopoly that is subjected to carbon emissions cap. The study assumes that in a departure from the classical Bertrand game, there is still a market for both firms’ goods regardless of the product price, even though production capacity is limited by carbon emissions regulation. Through the decentralized decision making of both firms under perfect information, the results are unstable. The firm with the lower maximum production capacity under carbon emissions regulation and the firm with the higher maximum production capacity both seek market price cooperation. By designing an internal carbon credits trading mechanism, we can ensure that the production capacity of the firm with the higher maximum production capacity under carbon emissions regulation reaches price equilibrium. Also, the negotiation power of the duopoly would affect the price equilibrium.

Coal mine dust continues to be a health and safety issue in underground coal mines. Coal seam water infusion was developed and widely applied in European coal mines for dust control, and was also a common practice in most Chinese coal mines. This method typically involves the infusion of water into the coal seam to increase its moisture content, and therefore reduce dust generation during mining operations. With the availability of other dust control methods such as water spraying systems, the water infusion method has not been considered as a viable means for dust mitigation in modern mines. However, the increase in production output and the deployment of more powerful equipment for coal cutting and transport and intensive gas drainage practices mean that workers could be exposed to more dust contaminations. Whilst the mine operators are committed to suppress and dilute airborne dust particles using these passive measures, there is a need to critically examine and subsequently develop this proactive dust control technology for practical applications in Chinese coal mines. The paper provides a critical review of the water infusion technologies in view of its technological advances and practical application limitations. The methods of water infusion, mechanism of water flow in coal, the role of surfactants and the key parameters influencing the effect of water infusion on dust control are identified and discussed. Existing problems and prospects for water infusion are analysed.

Total (all forms of inorganic and organic) concentrations of mercury (Hg) and selenium (Se) were measured in dorsal muscle and eggs of wild fishes from two shallow lakes in China: Tai Lake (Ch: Taihu; TL) and Baiyangdian Lake (BYDL). Hazard quotients (HQs) were calculated by dividing concentrations of Se or Hg in muscle or eggs of fishes by threshold concentrations for effects expressed as tissue residue toxicity reference values (TR-TRVs). Concentrations of Hg in whole bodies of fishes were estimated by concentrations in muscle. Based on concentrations of Hg in whole body, HQs for fishes in TL and BYDL were less than 1.0, which suggests little to moderate potential for effects on these fishes and unaccepted adverse effects of Hg are unexpected for adult fishes. HQs of Se in muscle of common carp from TL were closed to 1.0, and 27% of HQs based on concentrations of Hg in eggs of fishes from BYDL exceeded 1.0. Potential hazard due to Hg on common carp in TL and reproductive effects of Se on fishes from BYDL exhibited need for concern. Ratios of molar concentrations of Se to Hg were greater than 1.0. Thus, there might be some protective effects of Se on effects of Hg on fishes in TL and BYDL.

This study aims to evaluate the practical potential of using constructed wetlands (CWs) for treating saline wastewater containing various heavy metals. The results demonstrated that CWs growing Canna indica with porous slag as substrate could efficiently remove heavy metals (Cu, Zn, Cd, and Pb) from saline wastewater at an electrical conductivity (EC) of 7 mS/cm, especially under low influent load. Salts with salinity level (characterized as EC) of 30 mS/cm suppressed the removal of some heavy metals, dependent on heavy metal species and their influent concentrations. The presence of salts in CWs can improve the accumulation of Cu, Zn, and Pb in plant tissues as compared to control treatment, irrespective of metal concentrations in solution. The influence of salts on Cd accumulation depended on both salinity levels and Cd concentrations in solution. Although more heavy metals were accumulated in roots than in shoots, the harvesting of aboveground plant materials is still efficient addition for heavy metal removal due to the greater biomass and growth rate of aboveground plant material. Furthermore, replacing all plants instead of preserving roots from harvested plants in CWs over a period of time is essential for heavy metal removal, because the continued accumulation by roots can be inhibited by the increasing accumulated heavy metals from saline wastewater.

Analysis of limnic sediments can serve as a tool to assess sedimentary pollution for both the status quo as well as changes over time. However, in environmental studies, often only a small number of established well-studied contaminants are considered. This study focused on a more comprehensive investigation of sedimentary pollution of Djerdap Reservoir. Therefore, complementary analytical approaches were applied covering lipophilic organic contaminants and heavy metals. Investigations were performed on limnic sediment layers representing a period of 43 years of reservoir functioning. The core was sectioned on 11 samples and analyzed for, loss on ignition (LOI), and organic compounds (gas chromatography-mass spectrometry). Here, we report the quantitative data of 43 lipophilic organic compounds indicating both domestic and industrial emissions. Measured concentrations are generally low. Surprisingly, no polychlorinated biphenyls have been detected. Data concerning grain size, sedimentological, and inorganic composition were measured and published by in Kasanin-Grubin et al. (Kasanin-Grubin et al. 2019).

In Taiwan, because of the co-use of some irrigation and drainage canals, a portion of industrial wastewater was directly discharged into irrigation canals or even flowed into rivers or wetlands, causing the heavy metal pollution in waters and sediments. Mercury (Hg) contamination in rivers, irrigation canals, and wetlands has been found in Taiwan, but a thorough investigation on the distribution of Hg and methylmercury (MeHg) in these waters and sediments, which may be present in a greater level with elevating total Hg (THg) concentration and markedly impact human health, is still lacking. In this study, surface waters and surface sediments were sampled from five major rivers, two irrigation canals, two reservoirs, and one wetland in Taiwan, and their THg and MeHg concentrations were quantified. Additionally, statistical analysis was carried out to understand the relationship between sediment properties and MeHg levels. The results showed that irrigation canal sediments were relatively more polluted by Hg and the THg concentrations of some sampling points exceeded the upper limit (i.e., 0.87 mg kg⁻¹) of sediment quality index (SQI) for THg promulgated by Taiwan Environmental Protection Administration, which may be attributed to the co-use of irrigation and drainage canals. Furthermore, the MeHg concentration in irrigation canal sediments was the highest; rivers came in second followed by wetlands. In addition, the Siangshan Wetland was analyzed to have the greatest THg and MeHg concentrations in its surface water. Linear regression analysis also indicated that total organic carbon and clay content substantially affected the MeHg production in sediments.