Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 51
Filtrar
1.
J Environ Sci Health B ; 59(4): 131-141, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38314812

RESUMO

Small slaughterhouses generate biowaste, which for economic reasons, is generally destined for composting. Inoculating appropriate microorganisms can improve biodegradation efficiency and mitigate odor generation during the composting process and can give rise to composts with neutral or pleasant odors. Therefore, the aim of this study was to compare the odor intensity reduction of compost generated with and without a formulated inoculum (Saccharomyces cerevisiae, Bacillus subtilis, and Rhodopseudomonas palustris). A set of experimental data was collected and analyzed according to the German "Verein Deutscher Ingenieure" odor protocol. The results showed that adding microorganisms was effective in reducing unpleasant odors in all three composts generated from swine, cattle, and poultry slaughterhouse by-products during both summer and winter seasons. Additionally, soil odor was predominant in composts that were inoculated in the two tested seasons (i.e., summer and winter). On the other hand, composts without inoculation had odors similar to peat for swine compost, ammonia for cattle compost, and manure for poultry compost, regardless of the season tested. Overall, composting process with appropriate inoculum can help in the correct disposal of slaughterhouse wastes by transforming organic matter into composts, which can have economic and environmental value as a soil conditioner and/or fertilizer.


Assuntos
Compostagem , Animais , Bovinos , Suínos , Matadouros , Odorantes/prevenção & controle , Solo , Biodegradação Ambiental , Esterco
2.
Environ Sci Pollut Res Int ; 30(50): 108635-108648, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37752395

RESUMO

To understand which type of hospital waste may contain the highest amount of antibiotic resistant microorganisms that could be released into the environment, the bacterial strains entering and leaving a hospital wastewater treatment plant (HWTP) were identified and tested for their antibiotic susceptibility. To achieve this goal, samples were collected from three separate sites, inlet and outlet wastewater positions, and sludge generated in a septic tank. After microbiological characterization according to APHA, AWWA, and WEF protocols, the relative susceptibility of the bacterial strains to various antibiotic agents was assessed according to the Clinical and Laboratory Standards Institute guidelines, to determine whether there were higher numbers of resistant bacterial strains in the inlet wastewater sample than in the outlet wastewater and sludge samples. The results showed more antibiotic resistant bacteria in the sludge than in the inlet wastewater, and that the Enterobacteriaceae family was the predominant species in the collected samples. The most antibiotic-resistant families were found to be Streptococcacea and non-Enterobacteriaceae. Some bacterial strains were resistant to all the tested antibiotics. We conclude that the studied HWTP can be considered a source of resistant bacterial strains. It is suggested that outlet water and sludge generated in HWTPs should be monitored, and that efficient treatment to eliminate all bacteria from the different types of hospital waste released into the environment is adopted.


Assuntos
Esgotos , Águas Residuárias , Humanos , Esgotos/microbiologia , Bactérias , Antibacterianos/farmacologia , Hospitais
3.
Environ Technol ; : 1-9, 2023 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-37482803

RESUMO

Environmental release of wastewater that contains cytostatic drugs can cause genotoxic impact, since these drugs act directly on the genetic material of aquatic organisms. Thus, the aim of this study was to evaluate the removal of the cytostatic drugs cytarabine (CTR) and methotrexate (MTX) using different physico-chemical methods individually (i.e. US, O3, H2O2 and UV) and combined (i.e. O3/US, US/H2O2, O3/H2O2 and O3/US/H2O2) under different pH conditions (4, 7 and 10). In the degradation tests, the efficiency of the methods applied was found to be dependent on the pH of the solution, with the degradation of CTR being better at pH 4 and MTX at pH 7 and pH 10. The US, H2O2 and US + H2O2 methods were the least efficient in degrading CTR and MTX under the pH conditions tested. The highest MTX degradation rate after 16 min of treatment at pH 7 was achieved by the O3 + H2O2 method (97.05% - C/C0 = 0.0295). For CTR, the highest degradation rate after 16 min of treatment was achieved by the O3 process (99.70% - C/C0 = 0.0030) at pH 4. In conclusion, most of the treatment methods tested for the degradation of CTR and MTX are effective. Notably, ozonolysis is an efficient process applied alone. Also, in combination with other methods (US + O3, O3 + H2O2 and O3 + H2O2 + US) it increases the degradation performance, showing a rapid removal rate of 70-94% in less than 4 min of treatment.

4.
Environ Sci Pollut Res Int ; 30(27): 70713-70721, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37155099

RESUMO

Agrochemicals used for treating and preventing aquaculture diseases are usually present in combination with other compounds, and the toxicity resulting from their chemical interactions presents an important reason to assess the ecotoxicity of compound mixtures in view to better understanding the joint action of chemicals and avoiding their environmental impacts. In this study, we evaluated the acute aquatic ecotoxicity of several compounds used in Brazilian fish farming (Oxytetracycline [OXT], Trichlorfon [TRC], and BioFish® [BIO]), both individually and in binary and ternary mixtures. Initial test concentrations were prepared according to the recommended concentrations for aquaculture application, and from these, a geometric dilution series was tested on two important fresh water quality indicator species, the microcrustacean Daphnia magna and the bacterium Aliivibrio fischeri. At the recommended pond application rate, TRC and BIO applied individually showed toxicity to the tested organisms in terms of the lowest-observed-effect concentration (LOEC), and D. magna was always more sensitive than A. fischeri. For the two test organisms, the results obtained with the binary mixtures showed that the TRC and BIO mixture was more toxic than TRC and OXT, which in turn was more toxic than OXT and BIO. The toxicity from all agrochemicals in the ternary mixture was more than that of the agrochemical combinations in the binary mixtures. Given the results presented in this study, it is evident that the mode of action and availability of the tested compounds undergo changes that increase toxicity when they are present in combination, and therefore, aquaculture wastewater treatment should be adopted to ensure decontamination of agrochemical residues.


Assuntos
Oxitetraciclina , Poluentes Químicos da Água , Animais , Agroquímicos/toxicidade , Brasil , Aquicultura , Oxitetraciclina/toxicidade , Daphnia , Poluentes Químicos da Água/análise , Aliivibrio fischeri
5.
Artigo em Inglês | MEDLINE | ID: mdl-36734197

RESUMO

The literature reports the presence of multiresistant microorganisms in wastewater discharged from municipal and hospital wastewater treatment plants (WWTPs). This has led to questions concerning the disinfection efficiency of the treatments applied. Thus, this study aimed to assess the efficiency of different chemical oxidation methods to disinfect and to degrade bacterial plasmids present in hospital wastewaters, to avoid the dispersion of antibiotic resistance genes in the environment. The methods tested were UV254nm alone or associated with an Ag or Ti-photocatalyst in photo-peroxonization (UV254 nm/H2O2/O3/Ag2O/Ag2CO3@PU or UV254 nm/H2O2/O3/TiO2@PU) under different pH conditions (4, 7, and 10). The application of plasmid DNA electrophoresis to hospital wastewater treated using an advanced oxidation process (AOP) achieved the total structural denaturation of microorganism plasmids at the three pH values tested. Also, UV254 nm alone was partially efficient in the disinfection of hospital wastewater. AOPs performed with the two functionalized catalysts resulted in 100% disinfection after 10 min at the three pH values tested. No intact plasmids were observed after 20 min of treatment with photocatalysis. This study could contribute to the development and improvement of wastewater treatment aimed at mitigating the spread of multiresistant microorganisms in the environment.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Águas Residuárias , Peróxido de Hidrogênio/química , DNA , Bactérias/genética , Plasmídeos/genética , Oxirredução , Hospitais , Purificação da Água/métodos , Desinfecção/métodos
6.
Environ Technol ; : 1-8, 2022 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-36355390

RESUMO

In this article, the environmental sustainability of a circular economy concept applied to the management of biowaste was studied. To achieve this goal, the composting performance, compost-amended soil health, and phytotoxicity were assessed in the case of management of solid waste from a small swine slaughterhouse. Microorganisms present in a similar composting process were used as inoculums to improve the efficiency of composting. Addition of the inoculum promoted a faster and more efficient composting process than composting without the inoculum. The physical, chemical, and microbiological characteristics of soil were considered to be improved after compost application. Phytotoxicity tests in soils with and without compost amendment showed that a soil-compost mixture (90:10 and 70:30 mass ratios) was not phytotoxic to the plant species Sorghum saccharatum and Lepidium sativum, and that soil with compost showed higher plant biomass growth than that without compost amendment. The triple bottom line methodology used in this study can help in the assessment of circular economy activity in relation to the environmentally sustainable management of solid waste generated in small swine slaughterhouses.

7.
Artigo em Inglês | MEDLINE | ID: mdl-36281981

RESUMO

The goal of this study was to assess the efficiency of antibiotic degradation applying different chemical treatment methods and their combinations. Thus, improvement in the efficiency of these methods when combined was quantified. The methods tested to degrade/mineralize the antibiotics amoxicillin (AMX) and ciprofloxacin (CIP) under different pH conditions (4, 7 and 10) were ultra-violet irradiation (UV254 nm), ultrasound (US), hydrogen peroxide (H2O2) and ozone (O3) alone and in combination. The results showed that individual methods were only partially efficient in the degradation/mineralization of antibiotics, except for ozonation at alkaline pH. In the combined methods, the best performance was obtained with US/UV/H2O2/O3 (pH 10, 20-min treatment), where the degradation rates for the antibiotics were 99.8% for CIP and 99.9% for AMX. For the mineralization efficiency the values obtained were 71.3% for CIP and 79.2% for AMX. The results of this study could contribute to the development and improvement of wastewater treatment aimed at avoiding the presence of residual antibiotics in the environment.


Assuntos
Ozônio , Poluentes Químicos da Água , Purificação da Água , Peróxido de Hidrogênio/química , Poluentes Químicos da Água/análise , Oxirredução , Amoxicilina , Ciprofloxacina/química , Antibacterianos/química
8.
J Environ Sci Health B ; 57(9): 756-764, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36039562

RESUMO

The composting process is an option for acceptable environmental management of cattle slaughterhouse by-products. The goals of this article were (i) to make a low-cost inoculum using popular supermarket ingredients and microorganisms that are already present in the composting environment, and (ii) to compare the efficiency of the composting process with and without the application of formulated inoculum. Initially, a consortium of microorganisms already present in the composting environment (Saccharomyces cerevisiae, Bacillus subtilis, and Rhodopseudomonas palustris) was prepared in a low-cost culture medium for use as an inoculum for the composting process. The composting process with the addition of the inoculum was more efficient than the composting process without the inoculum, in terms of both the chemical composition and the process efficiency, but mainly in relation to the time required for composting, with the mean times for decay of 50% of the windrows' temperature (taking in to account the difference between internal and external windrow temperatures) being 96 days without inoculum and 65 days with inoculum. Thus, inoculum made with low-cost supermarket products reduced the composting time and yielded compost of better quality.


Assuntos
Compostagem , Matadouros , Animais , Bovinos , Solo/química , Temperatura
9.
Environ Technol ; : 1-9, 2022 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-35802062

RESUMO

This article seeks to characterize the bacterial profile of pediatric hospital wastewater samples collected at the outlet of a wastewater treatment plant, and to estimate their relative susceptibility to antimicrobial agents. A total of 64 strains were isolated in the wastewater samples, of which 49 were identified as belonging to different families: Enterobacteriaceae (e.g. Escherichia coli, Klebsiella sp., Citrobacter sp.) comprised 57.2% of the identified bacteria, non-Enterobacteriaceae (e.g. Aeromonas sp., Pseudomonas sp.) comprised 30.6%, and Streptococcaceae (e.g. Enterococcus sp.) comprised 12.2%. The tests of the susceptibility of the bacteria to the antimicrobial agents used in the hospital showed that 100% of the bacterial species found discharged in the hospital wastewater treatment system were resistant to one or more of the antimicrobial agents according to the criteria of the U.S. Clinical Laboratory Standards Institute/National Committee for Clinical Laboratory Standards. The antimicrobial agent tests showed that meropenem, norfloxacin, ciprofloxacin, levofloxacin, and cefepime were the most effective antimicrobials against bacteria of the Enterobacteriaceae family. For bacteria of the non-Enterobacteriaceae family, norfloxacin, ciprofloxacin, levofloxacin, and cefepime presented the most effective antimicrobial action, whereas for bacteria of the Streptococcaceae family, ampicillin, vancomycin, and gentamicin were the most effective antimicrobials. Hospital wastewater treatment plants could be considered as places of selection pressure for bacterial resistance because of the presence of antibiotic-resistant bacteria coming from sewers or created at the treatment plant.

10.
Environ Sci Pollut Res Int ; 29(37): 56579-56591, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35338463

RESUMO

Urban afforestation can mitigate the effects of air pollution, but the suitability of plant species for this purpose needs to be determined according to pollution intensity and climate change. The goal of this study was to evaluate the sensitivity of different phytotoxicity endpoints using two native Brazilian plant species as models, Aroeira (Schinus terebinthifolius) and Cuvatã (Cupania vernalis). The sensitivity parameters evaluated could help in selecting the most air-pollution-tolerant plant species for use in urban afforestation programs. The two plant species were exposed, in a greenhouse, to the combustion gases of a diesel engine for 120 days, with daily intermittent gas exposure. Every 30 days, leaf injury (chlorosis and necrosis), biomass, and physiological/biochemical parameters (proteins, chlorophyll, and peroxidase enzyme activity) were evaluated for both plant species. For the two selected species, the endpoints studied can be ranked according to their sensitivity (or inversely the tolerance) to diesel oil combustion gases in the following order: peroxidase > biomass ≈ chlorophyll > protein > leaf injury. The endpoint responses of higher plants can be used to assess the suitability of particular plant species for use in urban afforestation areas with relatively intense vehicle traffic.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Alcaloides , Anacardiaceae , Poluentes Atmosféricos/análise , Alcaloides/farmacologia , Anacardiaceae/metabolismo , Brasil , Clorofila/metabolismo , Gases/metabolismo , Peroxidases/metabolismo , Plantas/metabolismo , Sapindaceae
11.
Chemosphere ; 288(Pt 2): 132595, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34662633

RESUMO

Deterministic and probabilistic ecological risk assessments were performed for the boron present in coastal waters in the region of the São Sebastião channel (coast of São Paulo State, Brazil) surrounding the outfall of the São Sebastião waterway terminal (TEBAR) and in reference areas far from the outfall. A set of ecotoxicity tests with 9 marine organisms (Lytechinus variegatus, Arbacia lixula, Skeletonema costatum, Asterionellopsis glacialis, Parablenius pilicornis, Artemia salina, Megabalanus coccopoma, Mysidopsis juniae and Hypnea musciformes) was performed in the laboratory. Ecotoxicity tests confirmed that boron presents low ecotoxicity, with Lytechinus variegatus being the most sensitive species studied, with an EC50 of 14.6 mg L-1 and a no-observed effect concentration (NOEC) of 6.75 mg L-1. According to the deterministic ecological risk assessment, no significant environmental impact is expected if we consider the most sensitive of the organisms tested and the highest concentration of boron found in the coastal waters (5.82 mg L-1).


Assuntos
Organismos Aquáticos , Boro , Boro/toxicidade , Brasil , Medição de Risco , Água
12.
Artigo em Inglês | MEDLINE | ID: mdl-34338138

RESUMO

The use of advanced oxidative processes (AOPs) is an efficient alternative for the treatment of textile wastewaters. The aim of this study was to assess the dye removal efficiency of a Fenton-based degradation process followed by a polishing step using biochar prepared from rice husk. Six recalcitrant textile dyes - Reactive Red 195 (D1), Synolon Brown S2 (D2), Orange Remazol RGB (D3), Yellow Synozol K3 (D4), Reactive Orange (D5), and Reactive Black 5 (D6) - were treated with Fenton and photo-Fenton processes (with and without biochar polishing) under optimized conditions. The results showed a general efficiency ranking: photo-Fenton + biochar ≈ Fenton + biochar > photo-Fenton ≈ Fenton. The Fenton process was also efficient for the regeneration of the dye-saturated biochar. The photo-Fenton + biochar process achieved the following color removal percentages: D1 (98.8%), D2 (99.7%), D3 (98.9%), D4 (96.3%), D5 (94.2%) and D6 (94.8%). This process was applied to a real conventionally-treated textile wastewater and analysis showed a reduction in BOD (87.5% degradation), COD (62.5% degradation) and color (93.5% mean removal). These results reveal the possibility for the reuse of the treated water for non-potable industrial uses, for example, floor washing or the cleaning of machines and toilet areas.


Assuntos
Eliminação de Resíduos Líquidos , Poluentes Químicos da Água , Carvão Vegetal , Corantes , Peróxido de Hidrogênio , Oxirredução , Têxteis
13.
J Environ Sci Health B ; 56(7): 675-684, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34319219

RESUMO

This work aimed to evaluate the impact of veterinary antibiotics on biomass phytoproductivity and soil enzyme activity. The soil was sampled in the city of Camboriú (state of SC, Brazil). The soil enzyme activity was assessed through hydrolysis of fluorescein diacetate (FDA), while phytotoxicity was tested using Lactuca sativa (lettuce). Results showed that the most appropriate exposure time to assess the impact of antibiotics on soil microbiology was 24 h, while the incubation time of 3 h was the most appropriate for FDA hydrolysis. Ampicillin and Amoxicillin at the tested concentrations did not interfere with the enzyme activity of the soil microbiota, while Oxytetracycline and Neomycin showed a significant reduction in soil enzyme activity. For the dry and wet biomass of lettuce, 2% Colistin and 1% Ampicillin were the treatments that reduced lettuce biomass. Hence, the use of excessive antibiotics in animal production may lead to environmental impacts and, in the future, to public health problems.


Assuntos
Poluentes do Solo , Solo , Animais , Antibacterianos/toxicidade , Brasil , Fazendas , Lactuca , Microbiologia do Solo , Poluentes do Solo/toxicidade
14.
Environ Sci Pollut Res Int ; 28(36): 49642-49650, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33942267

RESUMO

Recalcitrant dyes found in textile wastewater represent a threat for sustainable textile production due to their resistance to conventional treatments. This study assessed an alternative co-composting system for the treatment of recalcitrant textile dyes where textile industrial sludge, sewage wastewater, or sewage sludge were used as microbial compost inocula. The biodegradation efficiency of bioreactor trials and compost quality of the co-composting system were assessed by visible spectrophotometry and by a phytotoxicity test. The co-composting system (dry weight (dw) basis) consisted of 200 g of restaurant organic residues + 200 g sewage sludge (or 100 mL sewage wastewater, or 200 g textile sludge) + 100 mL of a 10% dye solution (Reactive Red 195, or Synolon Brown, or Orange Remazol, or Yellow Synozol, or Reactive Orange 122, or Reactive Black 5). After 60 days of composting, all dyes were biodegraded according to spectrophotometric data, with efficiency varying from 97.2 to 99.9%. Inoculum efficiency ranking was textile sludge > sewage sludge > sewage wastewater. Regarding compost quality, a phytotoxicity study with lettuce showed no toxicity effect. Thus, co-composting can be a low-cost and efficient method for recalcitrant textile dye biodegradation and for managing textile sludge in terms of waste recycling, contributing to environmental sustainability.


Assuntos
Compostagem , Esgotos , Corantes , Solo , Têxteis , Águas Residuárias
15.
Environ Sci Pollut Res Int ; 28(13): 16532-16543, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33387324

RESUMO

The degradation efficiency of the Fenton reaction or ozonolysis (O3) to treat soil contaminated by crude petroleum was studied in association with the sonolysis process. To quantify oxidation efficiency, total organic carbon (TOC) and chemical oxygen demand (COD) were measured, while biochemical oxygen demand (BOD5) was measured to estimate biodegradation potential. TOC removal efficiency ranged from 9 to 52% to the Fenton reaction without sonolysis, and 18% and 78% with sonolysis for reagent concentrations of 1% H2O2-100 mM Fe2+ and 20% H2O2-1 mM Fe2+, respectively. For ozonolysis (after 10 and 60 min of treatment), the reduction in TOC ranged from 9 to 43% without sonolysis and 15 to 61% with sonolysis. The Fenton reaction without sonolysis increased the biodegradability in relation to the non-oxidized sample by 6% (1% H2O2-100 mM Fe2+) and 26% (20% H2O2-1 mM Fe2+), and with sonolysis the corresponding values were 13% and 42%, respectively. The biodegradation potential under ozonolysis without sonolysis increased from 0.18 (10 min of treatment) to 0.38 (30 min of treatment), and with sonolysis these values were 0.26 and 0.58, respectively. Optimization of the remediation processes is essential to determine sequential treatment order and efficiency.


Assuntos
Ozônio , Petróleo , Poluentes Químicos da Água , Peróxido de Hidrogênio , Ferro , Oxirredução , Solo , Poluentes Químicos da Água/análise
16.
Artigo em Inglês | MEDLINE | ID: mdl-33090067

RESUMO

The minimum set of parameters that can be used to assess the adsorption capacity of activated carbon (AC) produced from termite bio-waste was determined. Three types of AC were prepared: AC600 at 600 °C, MAC600 at the same temperature and impregnated with FeCl3, and AC800 at 800 °C. The influence of the solution pH on the adsorption, adsorption kinetics, isotherms and thermodynamic parameters was considered to characterize the amoxicillin (AMX) adsorption process. The AC materials had surface areas (m2 g-1) of approximately 248.8 for AC600, 501.6 for AC800 and 269.5 for MAC600, with point of zero charge (pHPZC) values of 8.3, 7.5 and 1.7, respectively. A time period of 30 min was chosen for the adsorption kinetics, which was best represented by the pseudo-first-order model for AC600, the intraparticle diffusion model for AC800 and the pseudo-second-order model for MAC600. Regarding the isotherms, a maximum adsorption of 23.4 mg g-1 was found for AC800. In general, the thermodynamic parameters demonstrated a non-spontaneous process. It seems that the medium conditions, the adsorbate and adsorbent characteristics, and the Gibbs free energy are the most important parameters to be considered in a preliminary assessment of the adsorption efficiency of specific adsorbent/adsorbate pairs.


Assuntos
Amoxicilina/análise , Carvão Vegetal/química , Resíduos , Poluentes Químicos da Água/análise , Adsorção , Animais , Concentração de Íons de Hidrogênio , Isópteros/química , Cinética , Temperatura , Termodinâmica
17.
Chemosphere ; 262: 127647, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32739679

RESUMO

This study sought to use concentration-time-response surfaces to show the effects of exposure to toxic (semi-)metals on peroxidase activity in higher plants as a function of exposure-concentration and exposure-time. Maize (Zea mays L.) seedlings (i.e., leaves and roots) were exposed to arsenic (as As3+) or aluminium (as Al3+) under hydroponic conditions, and their biomass and peroxidase enzyme responses were assessed at different concentration-time-exposures. The 3D ecotoxi-profile generated with these data showed two distinct regions: the first region is formed by exposures (i.e., points for time-concentration pairings) that were not statistically different from the results of the control points (i.e., zero toxicant concentration and all exposure-times), whereas the second region is formed by exposure pairings with results that were statistically different to those obtained from control pairings. Overall, the data show that enzyme activity increased over a shorter exposure-time when there was an increase in the exposure-concentration of the toxicant, which can be seen on a 3-D toxicity profile. We propose that quantitative relationship ratios from different assessed endpoints (e.g., biomass and enzyme activity) and enzymatic concentration-time-response surfaces could be helpful in the field of environmental-policy management.


Assuntos
Arsênio/toxicidade , Peroxidase/metabolismo , Zea mays/fisiologia , Alumínio/farmacologia , Biomassa , Hidroponia , Oxirredução , Peroxidases , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Plântula/efeitos dos fármacos , Tempo , Zea mays/efeitos dos fármacos
18.
Environ Pollut ; 265(Pt A): 114675, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32806393

RESUMO

Urban afforestation can mitigate the effects of air pollution by acting as a sink for atmospheric emissions, but these emissions (e.g., combustion gases from diesel engines) can be a precursor of structural and physiological changes in higher plant species, which could compromise the success of afforestation projects. In this study, Guabiroba (Campomanesia xanthocarpa O. Berg.) plants were exposed in greenhouses to combustion gases emitted by a diesel engine over 120 days, with daily intermittent gas exposure. Every 30 days, leaf injury (chlorosis and necrosis), plant biomass and physiological/biochemical parameters (proteins, chlorophyll and peroxidase enzyme activity) were evaluated. The data obtained were used to construct a hierarchy of the sensitivity (and inversely, of the resistance or tolerance) of this higher plant species to the diesel oil combustion gases: peroxidase > biomass ≈ chlorophyll > protein > leaf injury. Variations in these parameters could be used for the early diagnosis of plant stress or as a marker for stress tolerance in trees. In the first case, a sensitive species could be used for the phytomonitoring of air quality and in the second case the lack of significant variations in these parameters would indicator tolerance of the plant species to air pollution. The results showed that Guabiroba, a plant native to the Atlantic forest, is sensitive to air pollution and could therefore be used for air quality monitoring, since all parameters analyzed were affected by the polluted air.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar , Monitoramento Ambiental , Gasolina , Emissões de Veículos/análise
19.
Artigo em Inglês | MEDLINE | ID: mdl-32347158

RESUMO

This work aimed to produce activated carbon (AC) from brewing industry waste (the malt bagasse) to adsorb Paracetamol. Malt bagasse was characterized by moisture and ash contents and thermogravimetric analysis. Three types of AC were prepared: C400 (400 °C) and C500 (500 °C) under oxidizing atmosphere, and CN550 (550 °C) under nitrogen atmosphere. Some of these ACs were characterized by pH, point of zero charge (pHPZC), infrared spectroscopy, N2 adsorption-desorption isotherms, scanning electron microscopy, and temperature-programed desorption of CO2 and NH3. A pHPZC value < 7.0 and high density of acid sites were identified for CN550. Specific surface areas were between 192.5 and 364.0 m2.g-1. Adsorption kinetic studies were performed in a batch system with 50 mL of Paracetamol solution (100 mg.L-1) under pH 4 and 0.75 g of adsorbent (optimized conditions). The time to reach adsorption equilibrium was 20 min with 98.3% Paracetamol removal for CN550 AC. The pseudo-second order model and the Langmuir isotherm best fitted experimental data. Brewing industry waste can be used as a source of organic matter for AC production, since the percentage of Paracetamol removal in this study showed that CN550 AC presentes high adsorption efficiency and economically viable production.


Assuntos
Acetaminofen/análise , Celulose/química , Carvão Vegetal/química , Resíduos Industriais/análise , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Adsorção , Indústria Alimentícia , Temperatura Alta , Concentração de Íons de Hidrogênio , Cinética , Nitrogênio/química , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica
20.
Artigo em Inglês | MEDLINE | ID: mdl-31924135

RESUMO

The influence of the pH and the contaminant desorption/emulsification on ozone (O3), ozone-hydrogen peroxide (O3/H2O2) and ozone-photolysis (O3/UV) oxidation reactions were performed to treat crude petroleum (CP) contaminated soil and water samples. Oxidation efficiency is also related to both free radicals formation in reaction medium (which is dependent of the pH), and contaminant availability (which is dependent of the compounds solubilization or desorption processes). Thus, batch basic processes of O3/H2O2 or O3/UV were improved with sonication system and surfactant addition. In the case of O3/H2O2 process, the reactions were performed at adjusted (pH = 11) and natural pH (free pH= 4-5). The effectiveness of the improved advanced oxidation processes were evaluated through the time-course analysis of the chemical oxygen demand (COD), biochemical oxygen demand (BOD5), and total organic carbon (TOC) values. For both improved treatment processes, CP-contaminated water samples displayed higher values for TOC removal and BOD5/COD ratios than CP-contaminated soil samples. The O3/H2O2 process provided better results than the O3/UV process regarding degradation efficiency, but the former is associated with higher treatment costs due to H2O2 consumption. Overall, oxidation treatment processes increase their efficiencies when reactions are carried out associated with solubilization and desorption systems promoted by sonication/surfactant action.


Assuntos
Peróxido de Hidrogênio/química , Ozônio/química , Petróleo/análise , Poluentes do Solo/análise , Raios Ultravioleta , Poluentes Químicos da Água/análise , Análise da Demanda Biológica de Oxigênio , Concentração de Íons de Hidrogênio , Modelos Teóricos , Oxirredução , Petróleo/efeitos da radiação , Fotólise , Solo/química , Poluentes do Solo/efeitos da radiação , Poluentes Químicos da Água/efeitos da radiação , Purificação da Água/métodos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...