Based on the Tapio decoupling model, this paper calculates the decoupling indexes of the transportation output and the transportation carbon emissions of China’s 30 provinces and municipalities from 2006 to 2015. The research period (2006–2015) is divided into the 11th Five-Year Plan period (FYP) (2006–2010) and the 12th FYP period (2011–2015). On this basis, we conduct a comparative analysis to describe the spatial-temporal evolution of the decoupling states of transportation output and transportation carbon emissions. Furthermore, in order to deeply analyze the reasons for the evolution of the decoupling states during the 12th FYP period compared with the 11th FYP period, the LMDI decomposition method is used to decompose and compare the factors affecting the transportation carbon emissions in the two periods. The results show the following: (1) from the national point of view, the decoupling relationship between transportation output and transportation carbon emissions improved gradually, with small fluctuations from 2006 to 2015; (2) from the provincial point of view, their decoupling states mainly were expansive negative decoupling and weak decoupling, and the spatial evolution of the two decoupling states is significantly different; (3) the reductions in the transportation energy intensity and transportation intensity were the main factors inhibiting the increase of transportation carbon emissions in the 11th and 12th FYP periods, respectively. The growth of per-capita wealth was the decisive factor driving the increase in transportation carbon emissions in the two periods; (4) in contrast to the causes of decreases in the carbon emission variations in the 11th FYP period, in the 12th FYP period, the significant reduction in transportation intensity is the main reason causing the significant decrease of carbon emission variations. However, the transportation energy intensity and the transportation intensity fail to reduce simultaneously in the two periods.

Biodiesel has been renowned as potential and alternative fuel for years. In order to improve the quality of the conventional fossil fuels, biodiesel, and air pollution from combustion, additives are essential to exploit. In this study, the uses of cerium oxide (CeO₂) nanoparticle additive for B20 fuel in a diesel engine are investigated. The CeO₂ nanoparticles with cetyl-trimethyl ammonium bromide are doped into the B20 fuel by using ultrasonicator. The purpose of the experimental work was adopted to enhance engine combustion and reduce the emissions with an approach of CeO₂ nanoparticle additive. The experiment was conducted on a diesel engine using different propagation of CeO₂ nanoparticle in blended mahua methyl ester fuel such as B20 + CeO₂ 50 ppm, B20 + CeO₂ 100 ppm, and B20 + CeO₂ 150 ppm. The obtained results are compared with the diesel and B20 fuels. The minor changes are obtained in B20 fuel properties due to the addition of CeO₂ nanoparticles. The performance of brake thermal efficiency and combustion of pressure data is observed to be enhanced by the addition of a metal-based additive. The CO, HC, and smoke are decreased for B20 fuel with nanoparticles. The NOₓ is reduced by dosing the CeO₂ due to the oxidation of unburned CeO₂ in the exhaust.

In order to remove aqueous radionuclides and find an appropriate method for the disposal of wild duckweed in eutrophic water body, alkali-treated duckweed biomass and duckweed-based hydrothermal biochar (hydrochar) and pyrolytic biochars of 300 and 600 °C were prepared. Their physicochemical properties were characterized carefully. The adsorption isothermal data fitted well with the Langmuir model and the maximum Langmuir adsorption capacities were 104.1, 96.3, 86.7, and 63.5 mg/g for hydrochar, modified biomass, and 300 and 600 °C biochars, respectively. The adsorption kinetic data fitted well with the pseudo-second-order kinetic equation. The sorption data of fixed-bed column also confirmed the high efficient removal of Th(IV) and fitted well with the Thomas model. The duckweed-based hydrothermal biochar is a low-cost adsorbent for Th(IV) removal, and it is also a resource utilization technology of the duckweed collected from eutrophic water body.

The present work studies the effect of butanol in thumba (Citrullus colocynthis) biodiesel in an IDI CI engine at varying percentages of 5 and 10% in 15 and 10% thumba biodiesel respectively with 80% diesel in each blend. Another blend was introduced with 80% diesel and 20% biodiesel without any additive. The experiment was conducted in a single cylinder four-stroke IDI CI engine at 1500 rpm varying from 25% to full-load (100%) conditions. The results showed diesel with less bio diesel and higher butanol in percentage gives good performance and emission compared to diesel at higher loads. Blend containing 10% bio diesel, 10% butanol, and 80% diesel (D80B10Bu10) showed higher cylinder pressure, heat release rate, BThE, and less NOₓ. Biodiesels gave less UHC, CO emissions. In this work, multi-objective fuzzy-based genetic algorithm was introduced for the best fit result. Four parameters were used for optimization (BSFC, BThE, CO, NOₓ). The result from genetic algorithm was taken for validation and the optimized result was found adequate after validation.

Molybdenum (Mo), an essential microelement for plants, animals, and microorganisms, is reported can reduce soil nitrogen (N) residues and regulate plant root growth, but little is known about its effect on soil N transformation in plant-root region. A specially designed rhizobox was used in the present study to investigate the N processes in rhizosphere and non-rhizosphere soils of winter wheat applied with different rates of Mo fertilizer. (1) In the rhizosphere soil, pH values increased with increasing rates of Mo application, nitrate (NO₃⁻-N) accumulated at the rates of 0.15 and 0.3 mg Mo kg⁻¹, potential denitrification activity (PDA) was significantly reduced by application of 0.15–1 mg Mo kg⁻¹, and the copy numbers of narG and nosZ genes were increased by application of 0.15–1 mg Mo kg⁻¹. (2) In the non-rhizosphere soil, NO₃⁻-N content decreased by application of 0.15–0.3 mg Mo kg⁻¹, and narG gene abundance increased obviously by application of 0.3–1 mg Mo kg⁻¹. (3) Soil pH, NO₃⁻-N, apparent nitrification rate (ANR), and nosZ gene abundance were significantly higher in rhizosphere than in non-rhizosphere soil. On the contrary, NH₄⁺-N and total N, PDA, the abundance of AOB, and nirK and nirS genes were significantly higher in non-rhizosphere soil. The results indicated that the N transformations in rhizosphere and non-rhizosphere soils were differently affected by soil application of Mo fertilizer, and rhizosphere played a more important role in soil N cycle processes. The regulatory effects of Mo on these processes were to increase plant biomass and N uptake, promote the NO₃⁻-N accumulation in rhizosphere soil, and weaken the denitrification in both rhizosphere and non-rhizosphere soils.

The formation of a common mycorrhizal network (CMN) between roots of different plant species enables nutrient transfers from one plant to another and their coexistence. However, almost all studies on nutrient transfers between CMN-connected plants have separately, but not simultaneously, been demonstrated under the same experimentation. Both conspecific and heterospecific seedlings of Cinnamomum camphora, Bidens pilosa, and Broussonetia papyrifera native to a karst habitat in southwest China were concurrently grown in a growth microcosm that had seven hollowed compartments (six around one in the center) being covered by 35.0-μm and/or 0.45-μm nylon mesh. The Ci. camphora in the central compartment was supplied with or without Glomus etunicatum and ¹⁵N to track N transfers between CMN-connected conspecific and heterospecific seedlings. The results showed as follows: significant greater nitrogen accumulations, biomass productions, ¹⁵N content, % Nₜᵣₐₙₛfₑᵣ, and the Nₜᵣₐₙₛfₑᵣ amount between receiver plant species ranked as Br. papyrifera≈Bi. pilosa > Ci. camphora under both M⁺ and M⁻, and as under M⁺ than under M⁻ for Ci. camphora but not for both Bi. Pilosa and Br. papyrifera; the CMN transferred more nitrogen (¹⁵N content, % Nₜᵣₐₙₛfₑᵣ, and Nₜᵣₐₙₛfₑᵣ amount) from the donor Ci. camphora to the heterospecific Br. papyrifera and Bi. pilosa, with a lower percentage of nitrogen derived from transfer (%NDFT). These findings suggest that the CMN may potentially regulate the nitrogen transfer from a donor plant to individual heterospecific receiver plants, where the ratio of nitrogen derived from transfer depends on the biomass strength of the individual plants.

Rodents infest urban environments, causing damage and acting as vectors for disease transmission. Currently, anticoagulants are the most widely used chemical rodenticides, and their extensive and widespread use can contaminate the environment. To ensure effectiveness and avoid accumulation of rodent baits in the environment, it is important to evaluate how long rodent baits maintain their palatability and efficacy. In rodent control programs, rodent baits are placed in locations such as sewers, but after a few days, baits appear altered, causing doubts about the control efficacy. For this reason, baits are replaced periodically, which increases costs and generation of chemical waste. The objective of this study was to evaluate the palatability and efficacy of commercial paraffin-type rodent bait blocks placed in sewers in São Paulo City over a period of 90 days. Bait blocks were placed in sewers and collected after 30, 60, and 90 days. Additionally, in a laboratory two-choice test, wild-caught urban Norway rats were offered 40–60 g of bait and an equal volume of standard rat pellets. The amount of bait and rat pellet consumed was registered, the palatability was calculated, and the efficacy was measured as the percentage mortality over 14 days. The results showed that, even when they had an altered appearance, bait blocks remained palatable to the rats and were effective after at least 90 days. Leaving bait blocks for longer periods could be an effective strategy for reducing costs and could help to ensure the control of urban rodents in an environmentally sustainable way.

Three landfills are located in the eastern part of the Chengdu City, and two traffic tunnels pass beneath the south portion of landfill-1. The landfills have a simple leachate collection system without any bottom liner and impermeable wall, which causes a severe corrosion of the traffic tunnels from 175 to 250 m in the test section. In order to explore how the traffic tunnels impact the transport path of contaminants infiltrating from landfills, a groundwater flow model and a solute transport model were established in the present study. It was found that, after 16 years of operation, the traffic tunnels will accelerate the vertical migration of sulfate ions in the area between the tunnels. Furthermore, 64 water samples along the traffic tunnels were collected to test the concentration of the contaminants. According to the distribution mechanism of the measured concentrations in the traffic tunnels, a preliminary treatment plan was proposed to control the further corrosion of the tunnels and the spread of the contaminants.

An exhaustive overview of heavy metal pollution in Chaohu Lake illustrating enrichment intensity, temporal and spatial distribution, chemical speciation, and ecological risk under natural and anthropogenic changes was conducted. Low concentrations of heavy metals excluding Hg were found in water whereas high Hg might be ascribed to surrounding coal-fired power plants. Copper, Pb, Zn, Cd, and Hg were enriched in sediment whereas Cr and Ni were comparable to background values. Besides, As demonstrated an equal accumulation from natural and anthropogenic fluxes. Heavy metals were at a low level prior to the 1950s; it increased gradually during the 1950s–1960s owing to population growth and agricultural expansion; then it displayed abrupt increase since the late 1970s due to rapid modern urbanization and industrialization and agricultural intensification. Spatial distribution of heavy metals was a good indicator of natural and anthropogenic changes, where higher enrichment was found in the western lake. Apart from fluvial input, anthropogenic disturbances such as land use changes, atmospheric deposition, and algae-derived organic matter, along with natural stressors including climate change, hydrological alteration, and soil erosion, made significant contribution to the biogeochemical cycle of heavy metals in the lake. Heavy metals mainly from anthropogenic sources were dominantly partitioned in non-residual fractions, whereas those mainly from natural sources were predominantly distributed in residual form. Mercury and Cd were below the threshold effect concentration (TEC) indicating that adverse effects were excluded. However, result of chemical speciation demonstrated Cd would pose a considerable potential ecological risk. Besides, most of the heavy metals were in the range of TEC-PEC suggesting possible toxicity.

Phosphogypsum (PG) accumulation occupies huge amounts of land resources and results in serious environmental risks. A new recycling product, the phosphogypsum embedded filler (PGEF) made with calcination-modified phosphogypsum, was developed. The preparation process, hydration mechanism of PG, basic physical performances, environmental safety, engineering application, and cost analysis of the PGEF were studied. The results showed that the stress performance and thermal insulation property of the products were satisfied. Environmental performance tests established their findings that the application of PGEF prepared with calcination-modified PG does not cause any secondary contamination. In addition, the cost of PGEF is far lesser than that of the same volume of reinforced concrete. PGEF prepared with calcination-modified PG has shown a perfect application in cast-in situ concrete hollow floor structure.