Paraquat is resistant to degradation by conventional treatments, being necessary to use treatments with greater effectiveness, such as advanced oxidative processes. In this work, different advanced oxidative processes were applied (Fenton, electro-Fenton, photoelectro-oxidation and photoelectro-Fenton) employing oxide electrodes to degrade Gramoxone, a commercial herbicide that contains paraquat in its composition. The degradation and formation of by-products were accompanied by high performance liquid chromatography, total organic carbon (TOC) and chemical oxygen demand (COD). The results showed that the photoelectro-Fenton process was the most efficient due to the synergistic effect, reaching 79% degradation of the initial compound and 82% and 71% removal of TOC and COD, respectively. After the application of the electro-Fenton and photoelectro-Fenton oxidation processes, short-chain carboxylic acids such as succinic acid, oxalic acid, acetic acid and formic acid were identified as by-products of the oxidation of Gramoxone. The results were satisfactory and deserve to be highlighted, as a commercial formulation was used, making the scenario more realistic.
Inadequate disposal of Municipal Solid Waste (MSW) is one of the greatest environmental issues confronted nowadays. One of the techniques used for its final disposal is incineration, otherwise known as mass burning. Although this procedure remains very controversial in Brazil, some recent studies published in Europe reveal a large amount of misinformation about it. It has been widely used in European countries, Japan, and a few U.S. cities and has been increasingly and significantly adopted in China. Therefore, this article aims to carry out a literature review on the evolution of waste-to-energy recovery from Municipal Solid Waste (MSW) worldwide and the progress of mass-burning technologies, particularly in the Brazilian context. For such a purpose, global scientific databases were selected and some of their results allowed us to present how the main WtE recovery technologies function, as well as their benefits and impacts. Moreover, it was possible to systematize the main regulatory frameworks on the theme in Brazil and to reveal the country’s electricity generation capacity, in addition to depicting the progress of Waste-to-Energy Plants (WtEPs) undergoing licensing processes in the state of São Paulo.
16 May 2015 in Archives of Environmental Contamination and Toxicology
Wet distiller grains (WDG) are a corn by-product rich in protein and fiber that can be used in feedlot diets. This study evaluated F1 Angus-Nellore bulls fed on a control diet vs. WDG (n = 25/treatment). After a period of 129 days on these feeds, the animals were slaughtered and Longissimusthoracis samples were collected for both a meat quality evaluation and gel-based proteomic analyses. A greater ribeye area (99.47 cm²) and higher carcass weight (333.6 kg) (p < 0.05) were observed in the WDG-finished cattle compared to the control (80.7 cm²; 306.3 kg). Furthermore, there were differences (p < 0.05) in the intramuscular fat between the WDG and control animals (IMF = 2.77 vs. 4.19%), which led to a significant decrease (p < 0.05) in saturated fatty acids (FA). However, no differences (p > 0.10) were observed in terms of tenderness, evaluated using Warner–Bratzler shear force (WBSF). The proteomic and bioinformatic analyses revealed substantial changes in the biological processes, molecular functions, and cellular components of the WDG-finished cattle compared to the control. Proteins related to a myriad of interconnected pathways, such as contractile and structural pathways, energy metabolism, oxidative stress and cell redox homeostasis, and transport and signaling. In this experiment, the use of WDG supplementation influenced the protein expression of several proteins, some of which are known biomarkers of beef quality (tenderness and color), as well as the protein–protein interactions that can act as the origins of increases in muscle growth and reductions in IMF deposition. However, despite the effects on the proteome, the tenderness, evaluated by WBSF, and fatty acid profile were not compromised by WDG supplementation.
Pesticides ensure greater productivity in less time; however, they spread beyond the perimeters to which they are applied to reach non-target organisms, thereby affecting plant, animal, and human health. Thiamethoxam (TMX) is considered to be one of the main agents responsible for poisoning bees and potentially contaminating surface and groundwater. Conventional water-treatment protocols are unable to degrade thiamethoxam; therefore, electrochemically advanced oxidative processes (EAOPs) have become promising alternatives owing to their ease of operation and cost-effectiveness. Herein, we examined the use of EAOPs to oxidize thiamethoxam in commercial Actara® and analyzed treatment efficiencies through phytotoxicity studies using cucumber and maize seeds as bioindicators. In addition, the cost of each process was analyzed based on the resulting current efficiency. The treated solutions were used to germinate seeds that were analyzed for total protein, hydrogen peroxide, lipid peroxidation (MDA), superoxide dismutase (SOD), and catalase (CAT) activities. EAOPs were found to effectively oxidize TMX, with more than 50% degraded and 80% COD removed under all treatment conditions, even when the commercial product was used. The photoelectro-Fenton process using 10 mg L−1 FeSO4 and 100 mg L−1 H2O2 exhibited the best results, with 79% of the TMX degraded and 83% of the COD removed, additionally exhibiting the lowest estimated operating cost (USD 1.01 dm−3). Higher enzymatic SOD and CAT activities, total protein content, and H2O2 concentration were observed; however, no significant changes in MDA were recorded. This treatment protocol effectively oxidizes TMX and reduces its phytotoxicity in maize and cucumber seedlings.