Plastic pollution is the biggest threat to marine ecosystem owing to its high rates of disposal and low recovery from the environment. Due to inefficiency in degradation, most of plastic is fragmented into microplastics that are reported as ubiquitous toxicants in marine environment. The abundance of toxic microplastics in marine ecosystem causes adverse impacts on aquatic flora and fauna including oceans, lakes, rivers, coastal areas, and seas. This aggravates its toxicity and induces genomic instability, oxidative stress and disruption of marine organisms. Hence, it is necessary to understand the potential sources, types and behaviour of microplastic in marine environment. In this review, considering the pollution of aquatic ecosystem, major contributors of microplastics in marine environment along with their classification are brought out. Also, behaviour mechanisms of microplastics including physical, chemical and biological behaviours together with their ecological and toxicological impacts on marine ecosystem are illustrated. Finally, the remediation measures to combat against toxic microplastic pollution in aquatic ecosystem are highlighted to bring out an instant remedy for the environment.

Herbicides reduce the unsafe effects of weeds, but they are likely to have negative impact on essential and secondary metabolism in crops. However, the combined effect of different herbicides on chemical constituents of different varieties of wheat is still not fully obvious. The current investigation was carried out to determine the effects of three post-emergence herbicides (pinoxaden, tribenuron-methyl, and pyroxsulam) on total protein, lipid, and carbohydrate concentrations of three bread wheat cultivars (Misr 1, Giza 171, and Gemmiza 11). These herbicides were added individually and in combinations at recommended and/or half recommended doses. Our findings revealed that the individual application of herbicides decreased total protein and total lipid concentrations in fresh shoots of the three studied wheat cultivars, but increased total carbohydrate concentration. Combined addition of herbicides at recommended and half recommended doses generally decreased the concentrations of total proteins, total lipids, and total carbohydrates. However, the combined addition of tribenuron-methyl and pinoxaden at recommended dose enhanced total protein and total lipid concentrations under Misr1 and Gemmiza 11 cultivars compared to control treatment. Furthermore, the combined addition of tribenuron-methyl and pyroxsulam at half recommended dose enhanced total protein concentration in Giza 171 up to 15.05% and Gemmiza 11 up to 15.09% cultivars, and total lipid concentration in Misr 1 (7.53%) and Giza 171 (9.81%) cultivars against control treatment, where it was the lowest. Total carbohydrate concentration was enhanced by the sole application of pinoxaden by 53.55%, 52.40%, and 51.79% for Misr 1, Giza 171, and Gemmiza 11 cultivars, respectively. Moreover, individual or combined additions of the studied pesticides at recommended and half recommended doses negatively affected wheat grains under all cultivars via decreasing their concentration of nutrients (nitrogen, phosphorus, and potassium) as well as total protein and total carbohydrates. The highest reduction of nitrogen, phosphorus, and potassium concentrations compared to control was observed when tribenuron-methyl+pyroxsulam was applied at the half recommended dose under the three studied cultivars. However, the combined application of tribenuron-methyl+pyroxsulam at the half recommended dose caused the great depression in total proteins and total carbohydrates of wheat grains. Under the stress effect of herbicides, individual application of pinoxaden gave the best results for nitrogen and potassium content as well as total protein and total carbohydrate concentrations in the three studied wheat grain cultivars.

The article presents the results of the study of sulfur-containing gases (carbon disulfide, CS₂, and dimethyl sulfide, C₂H₆S) in the air above the sulfide tailings and in the soils in Komsomolsk settlement. Concentrations of CS₂ (gas of the second hazard class) and C₂H₆S (gas of the fourth hazard class) in the air above the tailings exceeded the average maximum permissible on-time concentration (MPCot) by 20 times and 9 times, accordingly. Because of the alarming medical statistics on childhood morbidity, vegetable gardens in houses in the settlement were selected for measuring gas concentrations and metal contents. Concentrations of CS₂ varied from 2.2 to 27 µg/m3 and exceeded MPCdn at 24 locations out of the 31 selected points. Concentrations of C₂H₆S varied from 120 to 440 μg/m3 and exceeded MPCot at 9 out of the 31 points. Particularly high gas concentrations were detected at a school and kindergarten. Geochemical study showed high concentrations of arsenic, zinc, and lead in garden soils compared to their background values. Mathematical models of the distribution of hazard indices indicated that about 633 residents of Komsomolsk are at risk of diseases related to respiratory organs and liver damage, and approximately 215 inhabitants of Komsomolsk are exposed to the combined effects of CS₂ and C₂H₆S and are at a risk of neurotoxic disorders.

The magnetic Fe₃O₄ was synthesized by using a one-step solvothermal method. Then, anhydrous ethanol as a solvent, tetramethyl ammonium hydroxide (TMAOH) as an auxiliary agent, tetraethyl orthosilicate (TEOS) as a silicon source, and (3-aminopropyl) triethoxysilane (APTES) as amino source were used to prepare Fe₃O₄@mSiO₂-NH₂ by using the sol-gel method. Uniform design U14*(14⁵) and the response surface method (RSM) were used to optimize the synthesis ratio. According to the results of TEM, SEM, N₂ adsorption–desorption test, VSM, and XRD, it found that the best coating effect obtained when the relative molar ratio of TMAOH:TEOS:APTES:Fe₃O₄ was 5:4:6:0.45. The results of EDS and elemental analysis confirmed the success of amino group coating; VSM magnetization after surface modification was 32 emu/g; BET results show that specific surface area is 236 m²/g, size 5 nm, and the pore volume is 0.126 cm³/g. The removal of Cu²⁺, Zn²⁺, and Pb²⁺ by Fe₃O₄@mSiO₂-NH₂ was studied at the optimal initial pH value 6 of the adsorption test system. The isothermal adsorption results show that the Langmuir model and Redlich–Peterson model are more suitable than the Freundlich model to describe the adsorption behavior, and Cu²⁺, Zn²⁺, and Pb²⁺ adsorption is mainly single molecular layer. The maximum adsorption capacity qm of the Langmuir model for Cu²⁺, Zn²⁺, and Pb²⁺ removal was 48.04 mg/g, 41.31 mg/g, and 62.17 mg/g, respectively. The adsorption kinetic rates of Cu²⁺, Zn²⁺, and Pb²⁺ on Fe₃O₄@mSiO₂-NH₂ relatively more suitable for pseudo-second-order kinetic model, i.e., R², were ranged between 0.995 and 0.999, and the suitable reaction time was 60 min. These results proved that Fe₃O₄@m-SiO₂-NH₂ prepared by using this method is easy to synthesize, has easy recovery, is ecofriendly, and can be potential adsorbent for Cu²⁺, Zn²⁺, and Pb²⁺ removal.

As a major carbon emitter in China, the emission mitigation in industrial sector performs great significance for China to achieve its emission reduction targets. Using the provincial panel data during 2000–2016 of China’s industrial sector, this paper first used a gravity model to study the spatial distribution and center of gravity of industrial CO₂ emissions. Then, an integrated decomposition approach based on Shephard distance functions was adopted to study the driving factors of industrial carbon intensity. Results indicate that during 2000–2016, industrial CO₂ emissions center of gravity gradually moved to the west. China’s industrial carbon intensity achieved considerable decline, with the annual change rate of 8.27%. The energy intensity decline, technology progresses of both production and energy saving were the most important factors facilitating carbon intensity decline. However, energy structure adjustment exerted positive effects in carbon intensity increase, although its effects were minor. Industrial carbon intensity witnessed decrease in almost all provinces except Xinjiang. The effects resulted from various factors were also different across provinces. Finally, suggestions were proposed to further decrease industrial carbon intensity.

Improving the accuracy of the green total factor productivity (GTFP) calculation has certain theoretical and practical value for sustainable development. We use a slack-based directional distance function (DDF) proposed by Färe and Grosskopf (European Journal of Operational Research 200:320-322, Färe and Grosskopf, European Journal of Operational Research 200:320–322, 2010) to combine with Malmquist-Luenberger Productivity Index (MLPI) to re-examine the GTFP. This new GTFP index takes inputs such as energy consumption, labor, and capital stock into account, while considering the comprehensive outputs of real GDP and three types of industrial wastes (gas, solid, water). The proposed slack-based MLPI is applied to access GTFP changes and compare the results under the slack-based DDF measure and original DDF measure over the period 2005–2012. The primary results in this paper present the average growth of GTFP for these 30 Chinese provinces shows a downward trend until 2010 suggesting that most provinces pay less attention on the productivity growth. The downward trend results primarily from no significant improvement in technical change. We also discover that although the distributions of the slack-based measure are roughly similar with that of the original DDF, the decomposed component, efficiency change, shows a significant difference between them.

Tannery sludge that has accumulated in the natural environment of a tannery industrial zone for a long time contains large amounts of toxic heavy metal elements such as Cr, which has a serious impact on the surrounding environment. This study used indigenous acidophilic sulfur-oxidizing bacteria from local tannery wastewater treatment plants to examine the effects of bioleaching on the removal of heavy metals in local tannery sludge accumulated in the natural environment. The effect of pre-oxygenation on bioleaching was investigated, and trends of sludge dewaterability during bioleaching and changes in the total amount of heavy metals, total nitrogen (TN), and total phosphorus (TP) during bioleaching were determined. Changes in the contents of different bound forms of heavy metals in tannery yard sludge during the bioleaching process were revealed. The experimental results showed that pre-oxygenation treatment of tannery yard sludge can shorten the bioleaching period (by at least 4 days) and improve the removal efficiency of all heavy metals. To ensure sludge dewaterability, the pH of the leaching system at the end of the bioleaching must not be lower than 1.67. The main components of heavy metals were stable in the tannery yard sludge, which critically affected the final removal efficiency of all heavy metals. The dissolution process of heavy metals showed that the morphology of heavy metals changed from stable to unstable forms in the bioleaching process, further dissolving into the liquid phase to be removed. In this experiment, the removal efficiency of all heavy metals in the tannery yard sludge was higher than 88.49%, and these heavy metals had good stability in morphology (the stable forms accounted for more than 87% of the total). In addition, the TN content in the remaining sludge was 27.9 g/kg, which is much higher than fertilizer TN requirements, indicating a high potential for resource utilization. Therefore, the method of bioleaching to remove heavy metals in tannery yard sludge for reuse is worthy of in-depth study and promotion.

A continuous flow filtration system was designed to identify and quantify the removal mechanisms of Cyanobacteria (Microcystis aeruginosa) by hydroponic biofilters of Phalaris arundinacea compared to synthetic filters. The filtration units were continuously fed under plug-flow conditions with Microcystis grown in photobioreactors. Microcystis cells decreased at the two flow rates studied (1.2 ± 0.2 and 54 ± 3 cm³ minˉ¹) and results suggested physical and chemical/biological removal mechanisms were involved. Physical interception and deposition was the main removal mechanism with packing density of the media driving the extent of cell removal at high flow, whilst physical and chemical/biological mechanisms were involved at low flow. At low flow, the biofilters decreased Microcystis cell numbers by 70% compared to the controls. The decrease in cell numbers in the biofilters was accompanied by a chlorotic process (loss of green colour), suggesting oxidative processes by the release of allelochemicals from the biofilters.

The Paris agreement (COP21) emphasized the need to progress toward using low-carbon energy technologies, including nuclear power, that is favorably looked for to meet the challenges to reduce an enormous increase in global temperature to below 2 °C. The cost of carbon pollution is highly induced by the energy sector that damages the global environmental sustainability plan. The alternative and nuclear energy demand is an optimized solution to decrease carbon damages, which can be better work under the imposition of carbon taxes on polluting industries. This study works in a given direction to analyze the role of alternative and nuclear energy, carbon pricing, FDI inflows, fossil fuel combustion, economic growth, and population density on the cost of carbon pollution in a panel of 90 selected countries for a period of 1995–2018. The results confirmed a “nuclear energy-augmented environmental Kuznets curve” with a turning point of 39.974% of total energy demand across countries. The result implies that alternative and nuclear energy initially increases carbon damages. Simultaneously, it decreases at the later stages of atomic energy expansion; thus, nuclear power growth is imperative for long-term sustainable development. A positive relationship is found between carbon pricing and carbon damage, while a negative relationship is between fossil fuel combustion and carbon damage across countries. The results conclude that expansion in nuclear energy would help reduce the cost of carbon pollution to achieve environmental sustainability agenda across countries.

The installation of district heating (DH) systems constitutes an advantage from the energetic, climate, and air quality aspects. However, the configuration and operational features of a DH system affect significantly its environmental performance. The objective of the present study is the energetic and environmental assessment of DH networks that present differences in size and operating configurations, to define relevant environmental performance indicators. Three case studies in Italy are analyzed, following a methodology based on the impact pathway approach that was presented by the authors in previous studies. Case studies are evaluated in terms of total emission, pollutant concentration (NOₓ, CO, PM), and health damage external costs. Results show that lower pollutant emissions are associated with the installation of a DH system compared to autonomous residential boilers. Air quality is also improved and health externalities are reduced. The results of CO₂ savings are differentiated depending on the efficiency and emission factors of the systems. An inter-comparison of different cases is then presented, based on the elaboration of specific indicators of environmental and health impacts. This section shows that, besides the size of the DH system, other factors, such as population density and geographical distribution of pollutants concentration, are important. Among the indicators considered, those based on health externalities provide more complete and comparable information on the final impact of the alternative solutions on the exposed population. Their application seems thus promising for the evaluation of alternative planning strategies for DH systems.