This study aimed to investigate the compression behaviors of mechanically biologically treated (MBT) wastes. For this purpose, the short-term compression-rebound and long-term compression tests were conducted on MBT wastes collected from Hangzhou Tianziling landfill in China. The results showed that the duration of immediate compression was obtained as 15.17–36.67 h and was comparable to municipal solid waste (MSW). The immediate compression ratio was 0.233–0.247, and it was comparable to the aged high food waste content (HFWC)-MSW, fresh and aged low food waste content (LFWC)-MSW, but much lower than the fresh HFWC-MSW. The mechanical creep ratio (C′αc) was 0.012–0.018, being close to the fresh and aged MSWs. The bio-induced compression ratio (C′αb) was 0.143–0.174. The compression ratio rose exponentially with temperature (5–42 °C) in both mechanical creep stage and bio-induced compression stage, and it increased much faster in the bio-induced compression stage. The resilient strains was only 2.1–3.3% of the compression strain at the same stress interval, suggesting that the compression strain consisted of mostly plastic deformation and negligible elastic deformation. The above findings can provide a reference for settlement prediction and storage capacity estimation of an MBT waste landfill.

Novel adsorbent, phosphoric acid-modified Paeonia ostii seed coats (PA-PSC) were successfully prepared by low-temperature pyrolysis to effectively remove Cu(II) from aqueous solution. The results revealed that equilibrium adsorption capacity (qₑ) of PA-PSC for Cu(II) was notably enhanced up to 4-folds compared with the raw PSC. FT-IR and XPS analyses suggested that the adsorption of Cu(II) by PA-PSC was primarily ascribed to electrostatic forces and complexing effects. Besides, equilibrium and kinetic studies demonstrated that Freundlich and pseudo-second-order models were the actually fairly good approximations of Cu(II) adsorption. Thermodynamic analysis revealed that the adsorption of Cu(II) onto PA-PSC was a chemical, endothermic, and spontaneous process. Lastly, reusability study further confirmed the applicability of PA-PSC as a promising adsorbent for removing Cu(II) from aqueous solution.

The outbreak of COVID-19 in Daegu, South Korea, early in 2020 has led this metropolitan city to become one of the major hotspots in the world. This study investigates the association of meteorology and the new daily COVID-19 confirmed cases and the effects of the city lockdown on the variation in criteria air pollutants (CAPs) in Daegu. Ambient temperature and relative humidity were negatively correlated to the new daily cases and played an important role in the spread of COVID-19. Wind speed could enhance the virus transmission through the inhalation of aerosols and/or droplets and contact with fomites. The lockdown has directly decreased the concentrations of CAPs. In particular, reductions of 3.75% (PM₁₀), 30.9% (PM₂.₅), 36.7% (NO₂), 43.7% (CO), and 21.3% (SO₂) between the period before and during the outbreak were observed over the entire city. An increase in O₃ (71.1%) was affected by natural processes and photochemical formation other than the lockdown effects. The three central districts were the areas most affected by the virus and showed the highest reductions in CAPs (except for O₃) during the outbreak. Apart from the influence of the lockdown, the decreasing trend in CAPs may be a result of the actions taken by the government to mitigate air pollutants nationwide since 2019. The results of this study can be useful for government and medical organizations to understand the behavior of the virus in the atmosphere. Further studies are necessary to explore the detailed influences of the lockdown on the environment and public life.

Soils have the potential to accumulate heavy metals and the capacity to do so is strongly related the properties of each soil. Soil organic matter is a key factor in the retention, release, and bioavailability of heavy metals, and here we have determined the accumulation of heavy metals in various types of humus in the Rybnik Forest District in southern Poland. In a novel approach, we analyzed relationships between heavy metals within soil organic matter fractions and evaluated the role of organic fractions in mediating metal mobility. Specifically, we tested whether (i) the type of forest humus determines the heavy metal accumulation; (ii) heavy metals accumulation is associated with soil organic matter fractions; and (iii) heavy metals have an inhibitory influence on biochemical properties especially enzymes activity in different humus types. Four types of humus were sampled (mor, moder, moder-mull, mull), physically fractioned, and a number of chemical and biochemical properties were analyzed. Calculated geo-accumulation index (Igₑₒ) and enrichment factor (EF) confirmed soil pollution with Cd and Pb. The type of humus differed in the accumulation of heavy metals, which is associated to the variable concentration of organic matter remaining at each decay class. We found no relationship between enzymatic activity and heavy metals concentration except for a positive correlation between urease activity and nickel concentration. Considering wider evidence, we propose a biogeochemical link between nickel deposition and the production of soil-borne urease in these forest soils.

The non-steroidal anti-inflammatory pharmaceuticals ketoprofen, meloxicam, and tenoxicam were degraded by photo-assisted peroxidation (hv/H₂O₂) and photo-Fenton processes under simulated solar radiation (sunlight) and UV-C. Preliminary studies showed that the processes under UV-C and sun-photo-Fenton radiation showed similar degradation results. The sun-photo-Fenton was less sensitive to the concentration variation of the H₂O₂ oxidant. Given that, in general, the highest percentages of degradation were achieved using the sun-photo-Fenton system and that this radiation resembles solar radiation, this process was selected for further studies. From the results of a factorial design 2³, in duplicate, the highest degradation condition within the studied levels was 400 mg L⁻¹ of [H₂O₂], 1.75 mg L⁻¹ of [Fe], and pH at 3–4 range. The kinetic degradation curve, monitored by the chemical oxygen demand (COD), could be represented by the pseudo-first-order model, and after 120 min the COD concentrations reached values below 2% of the initial demand. Degradation products from the three drugs were identified by high-performance liquid chromatography with coupled mass spectrometry (UCLAE-EM) and verified the toxicity of Escherichia coli and Salmonella enteritidis bacteria and of lettuce seeds (Lettuce Veneranda), indicating the formation of compounds that have lower molecular mass and can be more easily degraded, using this process as one of the stages of a system of treatment.

TiO₂-based heterogeneous photocatalysis systems have been reported with remarkable efficiency to decontaminate and mineralize a range of pollutants present in air and water medium. In the present study, a series of visible light active metal oxide TiO₂ nanoparticle were synthesized and evaluated for their photodegradation efficiency against emerging textile pollutant (Reactive Yellow 145) and antibacterial applications. In the first phase, nanomaterial synthesis was carried out following various synthesis parameters like addition of metallic impurities (different types and concentration) and calcination temperature. In the second phase, synthesized nanomaterials were screened for their performance in terms of photocatalytic degradation of RY145 and the best one (Fe-1-T-3 with 100% RY145 removal within 80 min of irradiation) was further optimized against various reaction parameters. To get knowledge about the insights of nanomaterial performance for degradation of different environmental pollutants, the most important is to understand their physicochemical properties utilizing different characterization techniques. The physical morphology and elemental dispersion of metal-doped TiO₂ nanomaterials were analyzed and results indicated that added metallic impurities were well dispersed onto the substrate surface. The efficient nanomaterials selected from initial screening were further assessed for photocatalytic disinfection efficiency against human pathogenic bacterial strains. Antimicrobial activities of the metal oxide nanomaterial were tested against gram-positive and gram-negative pathogenic bacterial strains. Possible mode of interaction of nanomaterial with bacterial DNA for bacterial cell inactivation was predicted using molecular docking simulation. The research project has the potential to contribute to multiple disciplines like material synthesis, water disinfection, and as green solutions for the textile industry replacing traditional technologies.

Lithium (Li) exploitation for industrial and domestic use is resulting in a buildup of the element in various environmental components that results in potential toxicity to living systems. Therefore, a soil culture experiment was conducted to evaluate the effects of increasing concentration of Li (0, 20, 40, 60, and 80 mg kg⁻¹ soil) on spinach growth, the effects of Li uptake, and its effects on various physiological attributes of the crop. The results showed that lower levels of Li in soil (20 mg Li kg⁻¹) improve the growth of spinach plants, while a higher concentration of applied Li enhanced the pigment contents. Higher concentrations of Li in soil interfered with potassium and calcium uptake in plants. Moreover, increasing Li concentration resulted in higher activities of antioxidant enzymes activity in spinach shoots. From these results, it is concluded that spinach shoot accumulated higher concentrations of Li without showing any visual toxicity symptoms. Therefore, the study concludes that Li ion was mostly deposited in leaves rather than in roots which may cause potential human health risk on the consumption of Li-contaminated plants. Therefore, the cultivation of leafy vegetables in Li-affected soils should be avoided to reduce the potential human health risks.

This paper presents a fresh understanding of the vigorous connection between inward FDI, renewable energy consumption, economic growth and carbon emission in the Chinese economy employing novel Morlet wavelet analysis. Wavelet correlation, continuous wavelet transform and partial and the multiple wavelet coherence analyses are applied on variables under study for data acquired during the period 1979 to 2017. The outcome of these analyses reveals that the connections among the variables progress over frequency and time. From the frequency domain point of view, the current study discovers noteworthy wavelet coherence and robust lead and lag linkages, although time domain reveals inconsistent associations among the considered variables. The wavelet analysis according to economic point of view supports that inward foreign direct investment (FDI) and renewable energy consumption help to enhance economic condition in Chinese economy. The results also suggested that inward FDI enhances the environmental degradation in medium and long run in China. The results emphasize the significance of having organized strategies by the policymakers to cope with huge environmental degradation occurred for a couple of decades in China.

Dust particles suspended in the atmosphere have been a big headache for electric power transmission industry in China. As transmission lines pass through dusty or air-polluted areas, dust contaminants are likely to deposit and accumulate on line insulators, which is one of the greatest causes of flashover and failure of power transmission. To study the statistical characteristics of this type of contamination, dust samples were collected and measured, and a physical model was set up to explain the deposition and accumulation mechanism of the particles. The trajectories of particles were tracked using fluid mechanics and contact mechanics, and an adhesion criterion was proposed. Simulation software was then applied to validate the model; further different environmental factors were studied that would affect the particle size distribution. The results show that under natural contamination conditions, the particle size distribution on the surface of the insulator shows a certain concentration at size ranges 1~100 μm and basically obeys a log-normal distribution. In addition, relative humidity, air velocity, and the charge accumulated on the surface all have significant influences on particle size distribution characteristics, while the effect of the electric field is mainly reflected in the difference in the number concentration of particle adhesion.

This study attempts to investigate the environment cleanness between the total factor productivity, natural resources and green taxation on Malaysia’s clean environment. Using the environmental Kuznets curve (EKC) hypothesis, this study employs the bootstrap quantile estimates based on the annual data series covering the period of 1970–2018 to analyse the quantile effect factors affecting environment cleanness in Malaysia. The empirical estimates of this study reject the EKC hypothesis throughout the quantile levels, while the green taxation shows a negative sign which indicated government fiscal policies are reducing carbon emission in the upper quantiles. There is also homogeneity slope equality effect between total factor of productivity and green taxation on carbon emissions in the middle and upper quantile levels, while natural resources are indication heterogeneity effect on all quantile levels. From the policy point of view, if Malaysia wants to get environment cleanness, there is a need for comprehensive policies of total factor of productivity with environment innovation-friendly and technological improvement in all major economic sectors of the country.