Metal Pollution in the Environment of Minas Gerais State – Brazil

Intense mining activities in Minas Gerais State – Brazil brings out tons of waste to the environment. Considerable concentrations of toxic elements penetrate the soil, ground waters and rivers. This endangers the environment quality not only in the surrounding areas but also in ichthyofauna and in more distant areas of cattle raising and agricultural activities. After seasonal floods, veterinary clinic studies have shown that most animals raised in this region are affected by symptomatologic nervous diseases, still not clearly diagnosed, which suggests intoxication. These pathologies are mostly noted after floods. Instrumental Neutron Activation Analysis was applied to determine Al, As, Au, Ba, Br, Ca, Cl, Co, Cr, Cs, Cu, Fe, Hg, K, La, Mg, Mn, Na, Nd, Rb, Sb, Sc, Sm, Th and Zn in environmental samples. The obtained results show that the water and sediment contaminated with heavy metals and toxic elements from the Das Velhas River upstream basin, the mining region, carry contamination to the ichthyofauna and farming region within a distance of approximately 400 km.     

Global variability of food waste chemical composition and its consequences on the production of biofuels and chemical compounds

Journal of Material Cycles and Waste Management - The use of food waste (FW) for the production of biofuels and value-added compounds is growing worldwide. However, the significant chemical...     

Removal of Hg2+ ions by adsorption using (TiO2@MnO2)-NPs nanocomposite

Journal of Material Cycles and Waste Management - Waste water contaminated with inorganic mercury is considered a serious environmental problem, mainly due to the hazardous effects this contaminant...     

Heterogeneous alternative catalysts: A bibliometric and systematic evaluation of their application in solar photocatalytic processes

The present study sought to objectively demonstrate how a researcher can, in a structured way, select relevant articles about alternative heterogeneous catalysts in photocatalytic processes. Therefore, the ProKnow-C (Knowledge Development Process – Constructivist) method was used to systematize the results found, with the application bibliometric and systematic analysis techniques for the evaluation of the results. The search string adopted as criteria was: solar photocatalysis AND heterogeneous catalysts OR alternative catalysts AND effluents. The databases were Web of Science, Science Direct and Scopus. The final bibliographic portfolio obtained for the research theme was made up of 19 articles. It was possible to verify advances in the number of publications on the theme over the evaluated period, with the Journal of Photochemistry and Photobiology A: Chemistry standing out in the final portfolio. Evaluating each article in the portfolio individually, it was possible to verify that most studies use combinations of catalysts already reported to create an alternative material to those already investigated in the literature. Those that use waste as catalysts chose to source this material from treatment plants and the steel industry. Around 58% of the papers used hydrogen peroxide in their processes, while 42% chose not to use it. Finally, approximately 63% of the papers in the portfolio used synthetic effluent in their processes, while the rest (37% of the research) chose to use real effluent. The results obtained in this research by applying the method can contribute to studies related to heterogeneous photocatalysis by alternative means over the years.     

Aquaculture expansion in Brazilian freshwaters against the Aichi Biodiversity Targets

The Convention on Biological Diversity proposed the Aichi Biodiversity Targets to improve conservation policies and to balance economic development, social welfare, and the maintenance of biodiversity/ecosystem services. Brazil is a signatory of the Aichi Biodiversity Targets and is the most diverse country in terms of freshwater fish, but its national policies have supported the development of unsustainable commercial and ornamental aquaculture, which has led to serious disturbances to inland ecosystems and natural resources. We analyzed the development of Brazilian aquaculture to show how current aquaculture expansion conflicts with all 20 Aichi Targets. This case suggests that Brazil and many other megadiverse developing countries will not meet international conservation targets, stressing the need for new strategies, such as the environmental management system, to improve biodiversity conservation.     

Resilience thinking applied to fisheries management: perspectives for the mullet fishery in Southern-Southeastern Brazil

The mullet fishery system encompasses a complex arrange of ecological and socioeconomic factors interacting in multiple scales on the Southern-Southeastern Brazilian coast. Similarly, to other fisheries in developing countries, overfishing and poor governance have been threatening the resilience of the mullet fishery. In this paper, we explore aspects related to fisheries management from the perspective of the concept of resilience. The industrial and artisanal fishery sectors represent the different stakeholders. The main issues of concern are related to failures in the fisheries management to properly address equity in resource access and resource use sustainability among stakeholders. Asymmetry in technology and political and economic power affect food security and income generation especially for subsistence and small-scale fishing. Despite changes in rules-in-use, overfishing and conflicts between resource users are still relevant. Fishery dynamics and resource availability are greatly affected locally by forces such as pollution, urbanization, non-selective fishing, and regionally, by the El Niño Southern Oscillation (ENSO), and industrial (purse-seine) fishery. Considering the influence of ENSO on this fishery, a time span of at least 7 years to investigate this system could provide better answers to improve the management. Effective resilient fisheries should rely on three aspects. First, there should be a flexible fish allocation system based on ecosystem variability. Secondly, fish allocation should prioritize food security and poverty alleviation. Thirdly, a monitoring system should be implemented that takes into consideration ecosystem, fisheries and human dimensions to support a flexible and adaptive fisheries management, with resilient fisheries as an ultimate goal.     

E‐waste in the world today: An overview of problems and a proposal for improvement in Brazil

Environmental issues have been at the center of society's concerns for a long time. Recently, this kind of concern is growing even more due to the damage caused to the environment by electrical and electronic product waste. Based on this same concern, this work aimed to analyze, through a literature review, the production and treatment of electronic waste in today's world, with an emphasis on Brazil and China. The articles reviewed point to an increase in the production of this type of waste, in both Brazil and China, and reveal that the current processes of treatment of electronic waste mostly aim to obtain profit through the recovery of precious metals such as copper. This paper concluded that although Brazil is one of the major producers of e‐waste, more than 90% of its e‐waste has not had a proper final destination. This deficiency in e‐waste treatment in Brazil is mainly due to financial factors and the lack of a robust educational policy focused on the environment. Thus, this work suggests the implementation of an effective educational policy aimed at environmental conservation, as well as investments in research on recycling methods in Brazil, especially on the use of e‐waste as an aggregate in the manufacture of concrete.     

Cell-based assays as an alternative for the study of aquatic toxicity of pharmaceuticals

An increasing number and amount of pharmaceuticals for human and veterinary use currently reach the aquatic environment, and the determination of their effects on aquatic organisms becomes of major importance. The 96-h fish lethal test is one of the conventional assays required for environmental hazardous assessment, but it is extremely time-consuming and costly, and it raises ethical concerns. In a broad study, we compared the ability of cell-based assays to detect, in absolute terms, lethal toxicity in fish due to pharmaceuticals in order to select sensitive cell lines to be posteriorly used as an alternative to fish testing. This study also explored the sensitivity of the rat cardiomyoblast H9c2(2-1) cell line and the suitability of the sulforhodamine B colorimetric assay regarding 15 pharmaceuticals belonging to 9 different therapeutic classes. The relation between in vivo and in vitro data was expressed as LC_50,96h/EC₅₀ ratios, and 66% of concordant data were attained. Accordingly, it was possible to conclude that cell-based assays could be considered a suitable alternative to fish lethal testing for pharmaceuticals, which, after validation, may dramatically reduce the number of fish required for environmental hazardous assessment. Several cell lines were selected as promising alternatives, but H9c2(2-1), HepG2, PLHC-1, and RTG-2 could be considered suitable starting cell types for further studies, as relevant results were obtained with low exposure times.

     

On the influence of faulting on small-scale soil-gas radon variability: a case study in the Iberian Uranium Province

In order to evaluate the influence of faulting on the variability of geogenic radon at detailed scale (1:2000), data on gamma ray fluxes, U and Th concentrations in rocks, radon in soil-gas and radon in groundwater were collected in three target areas on the Oliveira do Hospital region (Central Portugal). This region stands on the Iberian Uranium Province, and is dominantly composed of Hercynian granites and metasedimentary rocks of pre-Ordovician age, crosscut by faults with dominant strike N35°E, N55°E and N75°E. Radiometric anomalies are frequent, associated with faults of the referred systems and metasedimentary enclaves; the analytical data confirms that these anomalies are produced by local high uranium contents in rocks and fault-filling materials (n = 34, range 13-724 ppm), while other radiogenic elements are relatively constant (e.g. Th 4-30 ppm). Radon concentration in soil can be extremely high, up to 12,850 kBq m⁻³ (n = 215), with a large proportion of results above 100 kBq m⁻³. Unsurprisingly, groundwater also shows high radon concentrations, with observed values in the range 150-4850 Bq.L⁻¹ (n = 17). From the results it is concluded that metasedimentary enclaves, as well as faults, can accumulate uranium from circulating fluids, and as a consequence, strongly locally enhance geogenic radon potential. Due to this fact, for the purpose of land use planning in such uranium-enriched regions, very detailed geological mapping is needed to precisely recognize radon high risk areas. A correlation between radon concentration in soil or in groundwater and gamma ray fluxes was established pointing to the possible use of these fluxes as a first step in assessing geogenic radon potential, at least to geological setting similar to the study area.     

Laboratory appraisal of organic carbon changes in mixtures made with different inorganic wastes

Mixtures of organic and inorganic wastes were incubated to examine the changes in organic C (OC) contents. An anaerobic sludge and a CaO-treated aerobic sludge, with OC concentrations of 235 and 129 g kg^?1, were used. The inorganic wastes used – referred to as “conditioners” – were shot blasting scrap, fettling, Linz-Donawitz slag, foundry sand (FS), and fly ash from wood bark combustion (FA). The total OC (TOC) and ${\text{KMnO}}_4^{?}$ oxidized OC were determined. DTA-TGA profiles and FTIR spectra were also obtained. Mixtures made with the FS contained significantly lower (P < 0.05) amounts of TOC (45 g kg^?1) than the rest of mixtures, which was attributed to the non-existence of reactive surfaces in the conditioner and the increased aeration induced by this material. Those made with FA contained significantly higher (P < 0.05) amounts of TOC (170 g kg^?1), which was attributed to: (i) the addition of an extra source of C – black carbon (BC) – in the FA, and (ii) the inhibition of mineralization from the compounds present in this conditioner (e.g., amorphous aluminosilicates, BC). The results highlight the importance of the characteristics of the conditioners on the fate of the OM originating from the sludges.