This paper proposes the study and comparison of two commercial photocatalysts of TiO₂ when applied as coating on a fibrocement roof tile. Are reported their respective photocatalytic activities, chemical, morphological, and textural characteristics. For that, commercial photocatalysts InterBrasil® FA-101 and Fotosan® were deposited on fibrocement support to perform photocatalytic activity tests and characterization analyses. The measurement of the photocatalytic activity of each sample was carried out through the efficiency of H₂S degradation, using artificial (UV lamp) and natural (solar lighting) radiation. The surfaces formed with this photocatalyst coating were characterized by scanning electron microscopy, with energy-dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD), nitrogen adsorption-desorption isotherms, diffuse reflectance spectroscopy (DRS), and Fourier infrared transformation using attenuated total reflection (ATR-FTIR). The volumetric flow rate and saturation time (deactivation) were evaluated as operational performance parameters of the degradation reaction. The X-ray diffraction shows that TiO₂ formed in the coatings correspond to the anatase phase. In addition, the pore volume of the coatings was from 4.9 to 9.0 × 10⁻³ g cm⁻³ and the superficial area was from 19.6 to 30.5 m² g⁻¹ that is considered relatively high. The results showed that, unlike the Fotosan®, the type of radiation used had a greater influence on the InterBrasil® FA-101, since there was a reduction of the photocatalytic activity when the solar radiation was used. The H₂S degradation efficiency of 80% was obtained for a residence time (RT) of 115 s using Fotosan®, whereas that for InterBrasil® FA-101 was reached 45% for the same RT. Lower on the photocatalytic activity was observed after 30 min and 390 min of reaction for the InterBrasil® FA-101 and Fotosan®, respectively. The sample containing Fotosan® was the most effective photocatalyst in comparison with InterBrasil® FA-101.

End-of-life packaging materials (EOLPM) present an important challenge from an environmental and financial perspective at utility-scale solar energy (USSE) sites. Reuse on-site represents, in particular for remote sites, a significant contribution to sustainable business practice as it provides a higher value end use when used to develop on-site mulch to enable soil improvement, reducing transport emissions (from the least preferred option of off-site disposal to landfill), reducing costs, and employing local contractors. The objective of the study was to enable on-site reuse, which was primarily achieved through chemical and physicochemical characterization of EOLPM streams; cardboard, and wood. Given the common occurrence of these materials in the rapidly growing renewable energy sector, it represents an important scope of work for the sector internationally. The methods used for characterization of the EOLPM, the first of its type reported, included a range of organic and inorganic chemical analyses, phytotoxicity testing, followed by an environmental and high-level (or initial) financial benefit cost analysis. Key scientific findings were that only trace concentrations of chemicals of potential concern (COPC) were detected; the material was not phytotoxic and has potential for soil improvement at the site, and the selected option of on-site reuse (of the materials as a mulch) had a global warming potential of 50 times less than the business as usual option (transport to landfill). The results also demonstrated the broader potential for using EOLPMs from USSE sites for soil improvement at remote locations rather than transporting offsite for disposal or reuse. Structural changes will need to be made to the way in which markets operate to achieve circular economy outcomes for these EOLPMs.

Efficient removal of heavy metals from water and wastewater is a necessity for human and environmental well-being. Agricultural, domestic, and industrial waste discharges increase with the increase in the global population. Discharges are loaded with toxic metallic substances that inevitably reach water sources. Conventional treatment methods are in many cases inadequate in their removal efficiencies. Alternatively, recently developed advanced treatment approaches, such as nanotechnologies, offer advantages in water treatment. Nanotechnology brought about materials with high specific surface areas and adsorption capacities for the removal of undesirable heavy metals present in water. A detailed review of the use of nanotechnologies and nanomaterials for the removal of heavy metals from aqueous solutions is presented in this study. Limitations, research gaps, and suitability of nanotechnology in water treatment for the removal of heavy metals at a large scale are discussed, and relevant conclusions are accordingly deduced.

In leather industries, raw hides/skins are always preserved before being processed into leather. Salting method of preservation is the general and age old popular practice of preservation used in these industries. The main drawbacks of this method are the generation of huge amounts of pollution load, in terms of total dissolved solids (TDS), total suspended salts (TSS), and chlorides; and ecological damage which occurs as a result of these waste effluents being discharged into the ground. Therefore, finding cheaper and eco-friendly methods of preservation has become a major necessity for these industries. In this manuscript, we have used ethanolic extract of Aegle marmelos for preservation which totally eliminates salt. The efficacy of this method was assessed by evaluating parameters such as microbial count, nitrogen content, and collagen content of the skin samples, and biological oxygen demand (BOD), chemical oxygen demand (COD), TDS, and TSS of the waste effluents collected during processing of leather. It was found that this method showed a remarkable reduction in pollution loads like BOD (46%), COD (3-fold), TDS (many folds), and increased values of collagen content. Thus, we could conclude that preservation using A. marmelos was found to be more effective and eco-friendly.

Ground level ozone is a major air pollutant with known toxic effects on humans. The research field is well established with many scientists from developed and developing countries contributing original research articles. Strict regulations for ozone air pollution are being implemented worldwide based on supporting scientific literature. In this scientometric analysis, we have analyzed the research trends in the field of ozone air pollution during 2011–2019. The collected SCOPUS data was analyzed using common scientometric analysis methods for known indicators to identify top ten rankings and scientific collaborations important for the field. Our result demonstrates that the USA is leading the field as USEPA and American regulatory authorities have funded most of the research. Two scientists, Russell A.G. and Schwartz J., working in American institutions, are leading with the most publications. Our assessment of ozone and PM together shows a significant impact on research direction in the last years to accommodate the study of both air pollutants together. In addition, we have analyzed the possible disease trends in the field for the last 3 years and identified that cardiovascular system, nervous system, and diabetes are upcoming disease areas that would be studied in the coming future.

This study aims to investigate the changes in atmospheric deposition trends in Bulgaria, studied using the moss biomonitoring technique since 1995. For the first time, a paired (site-wise) comparison was performed after a critical review of the sampling networks and adjusting for location, the distance between the sampling points, and moss species. Data from the 2005/2006 and 2015/2016 moss surveys were chosen as instrumental neutron activation analysis was employed in both to determine the content of 34 elements (Al, As, Ba, Br, Са, Ce, Cl, Со, Cr, Cs, Fe, Hf, I, K, La, Mn, Na, Nd, Ni, Rb, Sb, Sc, Se, Sr, Ta, Tb, Th, Ti, Tm, U, V, W, Yb, Zn). In addition, Cd, Cu, and Pb were determined using complementary analytical methods: inductively coupled plasma atomic emission spectroscopy in 2015/2016 and atomic absorption spectroscopy in 2005/2006. For the subset of 57 routinely sampled locations in Bulgaria, hierarchical clustering on principal components and multiple factor analysis (MFA) were applied to assess the spatial trends in the 10 years elapsed between the surveys, as well as to characterise the origin of the determined elements. Elevation and distance between the sampling points were used as additional variables in the multiple factor analysis plane to ascertain their effect on the overall variance in the datasets. Distribution maps were constructed to illustrate the deposition patterns for the pollutant Pb. The results were consistent with decreased industrial output in the country, increased coal combustion and transport pollution, and construction of roads.

Increasingly severe environmental issues, especially those in developing countries such as China, drive the evolution of the environmental protection institution (EPI) to its strictest levels. However, the implementation of the strictest EPI still confronts various challenges and barriers, and the multi-stakeholder features of EPI determine these barriers are not independent of one another but rather present complex interactive relationships. This paper identifies the barriers to implementing China’s EPI from four aspects of environmental legal, economic, regulatory, and public participation institutions. A variable precision rough DEMATEL approach is proposed to visualize the causal relationships and intensities among barriers from the similarities and differences in perspectives of stakeholders from the government, company, and public levels. The obtained causal interactive mechanism among barriers highlights the need to prioritize the improvement of environmental policy assessment, and the concrete measures in policies or plans should be integrated into legislation to ensure they are mutually supportive early. The non-substantive contributions achieved by China’s public participation in environmental protection reveal prejudices that the public is often regarded as a supporter or spectator by both government and company groups, which makes the transparent environmental information disclosure, transfer and feedback into an effective mediation among stakeholders. Comprehensive coordination and feedback mechanisms including source prevention, process control, and severe punishment for consequences while enhancing linkages among stakeholders are put forward to overcome barriers and help implement the strictest EPI.

This paper has empirically explored the impact of macroeconomic and financial development on CO₂ emissions by utilizing a novel dynamic simulated ARDL model for annual time series data from 1982 to 2018 for Pakistan. The results of a novel dynamic simulated ARDL disclosed that the growth of stock market, FDI, economic growth, and consumption of oil wield a positive impact on CO₂ emission, while domestic credit exerts a negative effect on CO₂ emission both in the short and the long run in Pakistan. The stock market development and domestic credit wield a significant influence on carbon dioxide emission in Pakistan both in the long and the short run. FDI exerts significant impact only in the long run, while economic growth and consumption of oil wield significant impact only in the short run on CO₂ emission in Pakistan. This study opens up new visions for the economy of Pakistan to sustain financial and economic growth by protecting environment from pollution through its efficient national environmental policy, fiscal policy, and monetary policy.

Small-scale agriculture (SA) is regarded as unsustainability because of its low benefit. To protect traditional agricultural landscapes like terraces through SA will be difficult. However, in China, terraces are still maintained well by smallholders now. This study takes the family as a basic unit and SA in Hani terraced region as an object to explore its sustainability from the perspective of labor productivity (LP) through the questionnaire method. The findings are that peasant households work on both farm and non-farm jobs. They get a low income (3854.5 yuan RMB) from hybrid-rice-cropping and a high income (44,665.8 yuan RMB) from non-farm jobs but spend a small part of labors (34.23 person•days) in growing hybrid-rice and expended lots of labor (522 person•days) for non-farm jobs. In conclusion, LP of hybrid-rice-cropping is 1.32 times that of non-farm jobs for a household. The result shows SA in Hani terraced region has a higher return of labor investment than non-farm jobs. It is different from the common impression of the low benefit of SA and also explains why SA still continues to exist in the mountainous area in China now. However, SA in Hani terraced region also faces challenges with salary level rise of non-farm jobs and part-time farmers’ requirement for living quality improvement. In the future, promoting industrial integration development in this region to add local employment for improving farmers’ income is a feasible approach to protect terraced landscapes.

Despite the important niche and broad applicability of thermal remediation (TD), little work has been done to discuss chemical reactions of methylnaphthalene contaminated soil. The 2-methylnaphthalene desorption amount (MDA) of TD is studied here under different conditions, and the carbonation (chemically polymerized or condensed) behavior of 2-methylnaphthalene is explained by analyzing the changes of soil organic carbons (SOCs), off-gas products, and surface chemical properties. It indicates that the influence sequence of MDA from high to low is heating time, heating temperatures, and flow rates of carrier gas. MDA increases steadily with the increase of temperatures (200–300 °C) but decreases slightly after 300 °C; the reason may be the chemical conversion of 2-methylnaphthalene. GC-MS analysis of off-gas confirms that partial 2-methylnaphthalene is polymerized to form 2-methylbenzo[b]thiophene and 2,4-di-tert-butylpheno at 400 °C, which is the first step of carbonization process. The x-ray photoelectron spectroscopy results of soil indicate that the C content decreases, but C–(C, H) chemical structure increases, indicating that new carbonaceous substances are generated. A layer of “char” is seen by scanning electron microscope to be left on the surface of the soil particles. As the temperature increases (200–400 °C), the SOCs generally decreases from 1.14 to 0.82%, which is the result of the equilibrium between SOCs pyrolysis and 2-methylnaphthalene carbonization. Therefore, partial 2-methylnaphthalene turns into smaller organic molecules in desorption gas of TD, meanwhile is accompanied by its chemical conversion to non-volatile products, which are attached to remediated soils and then improve soil properties and increase their fertility. Graphical Abstract