RESUMO
Pesticides has transformed the agricultural industry, primarily by enhancing productivity. However, the indiscriminate use of such compounds can adversely affect human health and disrupt ecosystem balance. Limited knowledge exists regarding the removal of these compounds from water, particularly for organophosphate pesticides when employing conventional treatment technologies. Therefore, this study aimed to assess the removal of acephate (ACE) and methamidophos (MET) - considered priority pesticides in Brazil - from waters with high and low turbidity during the clarification process carried out with aluminum sulfate (AS) and ferric chloride (FC), either alone or combined with powdered activated carbon (PAC) adsorption. All water samples were submitted to solid phase extraction (SPE C18 cartridges) prior to acephate and methamidophos analysis by HPLC MS/MS. The clarification process with either AS or FC coagulant did not efficiently remove acephate or methamidophos and maximum average removal (27 %) was observed with waters of high turbidity when using ferric chloride as coagulant. Addition of mineral PAC was also ineffective for removing both pesticides. However, the use of vegetable PAC (10 mg/L) resulted in better removal percentages, up to 80%, but only for methamidophos. The limited removal rates were attributed to the high hydrophilicity of acephate and methamidophos, along with their neutral charge at coagulation pH. These factors hinder the interaction of such organophosphorus pesticides with the flocs formed during coagulation as well as with PAC surface.
Assuntos
Compostos Organotiofosforados , Fosforamidas , Poluentes Químicos da Água , Purificação da Água , Compostos Organotiofosforados/química , Poluentes Químicos da Água/análise , Adsorção , Purificação da Água/métodos , Compostos Férricos/química , Brasil , Compostos de Alúmen/química , Extração em Fase Sólida/métodos , Praguicidas , CloretosRESUMO
Alum sludge (AS) is a by-product generated from drinking water treatment and produced in large amounts around the world. Its chemical composition makes this waste an emerging alternative source of silicon and aluminum for aluminosilicates or zeolite material production, which can add value to residues and contribute to the circular economy process on a global scale. In this sense, and considering the scarcity of information about AS, this review shows data collection about AS in different countries, including generation, chemical composition, and disposal information. The reuse of AS is discussed based on circular economy and the environmental gains derived from such approaches are highlighted, including the possibility of utilization with other residues (e.g., ash, bioproducts, etc). Moreover, this review shows and discusses the benefits and challenges of AS reuse in the synthesis process and how it can be a sustainable raw material for aluminosilicates and zeolite synthesis. The most common conditions (conventional or non-conventional) in zeolite synthesis from AS are mentioned and advantages, limitations and trends are discussed. The discussions and data presented can improve the AS management and reuse legislations, which certainly will collaborate with sustainable AS use and circular economy processes.
Assuntos
Compostos de Alúmen , Silicatos de Alumínio , Reciclagem , Esgotos , Purificação da Água , Zeolitas , Zeolitas/química , Silicatos de Alumínio/química , Compostos de Alúmen/química , Purificação da Água/métodos , Reciclagem/métodos , Eliminação de Resíduos Líquidos/métodosRESUMO
Wastewater reuse has been widely discussed as an essential strategy to minimize the consumption of drinking water for less noble purposes. During biological wastewater treatment, organic matter is converted into a complex matrix containing a variety of soluble organic compounds. The objective of the present study was to evaluate the removal efficiency of the residual organic load in the final effluent from wastewater treatment plant with a conventional activated sludge process by different coagulants and parameters of coagulation-flocculation process, using dissolved organic carbon (DOC) concentration, molecular weight (MW) size distribution by size exclusion chromatography (SEC) coupled to mass spectrometry (MS), and zeta potential (ZP) analyses. The results showed a DOC removal efficiency up to 45% with iron chloride, and of 38% for aluminum sulfate and 31% for PAC coagulants. ZP was also measured during the procedures and authors conclude that the ZP also does not have a determining role in these removals. SEC and MS assessment was able to detect changes on secondary effluent molecular weight distribution profile after effluent coagulation-flocculation, this technique might be a promising tool to understand the composition of effluent organic matter and be helpful to estimate and optimize the performance of wastewater effluents treatment processes.
Assuntos
Floculação , Compostos Orgânicos/análise , Esgotos/química , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Purificação da Água/métodos , Compostos de Alúmen/química , Análise da Demanda Biológica de Oxigênio , SolubilidadeRESUMO
Blomia tropicalis mite is highly prevalent in tropical and subtropical regions and it is associated with allergic diseases such as rhinitis and asthma. By using an OVA-model of allergic lung disease, we have previously shown that sensitization in the presence of toll like receptors (TLRs) agonists attenuates subsequent OVA-induced allergic responses. Here, we evaluated the effect of CpG-ODN, a specific synthetic TLR-9 agonist, on the development of experimental asthma induced by Blomia tropicalis extract, a relevant source of aeroallergens. Among different protocols of Blomia tropicalis extract sensitization, the subcutaneous sensitization in the presence of alum adjuvant induced the highest Th2 responses, including high IgE levels. Adsorption of CpG to Blomia tropicalis extract/Alum attenuated the airway hyperreactivity, the infiltration of inflammatory cells including eosinophils, and the IL-5 content in BAL. In addition, lung peribronchial inflammatory infiltrate, mucus production and IL-5-producing CD3+ CD4+ T cells were significantly reduced in the Blomia tropicalis extract/Alum+CpG group. Importantly, CpG inhibited total IgE production as well as active systemic or cutaneous anaphylaxis reactions. Inhibition of pulmonary Th2 responses was associated with increased IL-10 production but not with IFN-γ production. Notably, in IL-10-deficient mice, sensitization with OVA/Alum+CpG resulted in intense lung neutrophilia and IFN-γ production, indicating that IL-10 is necessary to inhibit subsequent Th1 immunity. Our work highlights the mechanisms of allergy attenuation by CpG and it indicates the potential use of Alum-based formulation with CpG to treat allergic processes.
Assuntos
Adjuvantes Imunológicos/uso terapêutico , Compostos de Alúmen/química , Asma/prevenção & controle , Asma/parasitologia , Pyroglyphidae/fisiologia , Receptor Toll-Like 9/agonistas , Adjuvantes Imunológicos/farmacologia , Adsorção , Anafilaxia/complicações , Anafilaxia/imunologia , Anafilaxia/parasitologia , Animais , Asma/complicações , Citocinas/biossíntese , Modelos Animais de Doenças , Eosinófilos/patologia , Feminino , Hipersensibilidade/complicações , Hipersensibilidade/imunologia , Hipersensibilidade/parasitologia , Imunidade/efeitos dos fármacos , Imunização , Interleucina-10/metabolismo , Interleucina-4/biossíntese , Linfonodos/efeitos dos fármacos , Linfonodos/imunologia , Linfonodos/patologia , Subpopulações de Linfócitos/efeitos dos fármacos , Subpopulações de Linfócitos/imunologia , Camundongos Endogâmicos C57BL , Neutrófilos/patologia , Oligodesoxirribonucleotídeos/farmacologia , Pyroglyphidae/efeitos dos fármacos , Células Th1/efeitos dos fármacos , Células Th1/imunologia , Células Th2/efeitos dos fármacos , Células Th2/imunologia , Receptor Toll-Like 9/metabolismoRESUMO
The helminth Schistosoma mansoni is one of main causes of human schistosomiasis, a health and economic concern in some of the world's poorest countries. Current treatment regimens can lead to serious side effects and are not suitable for breastfeeding mothers. As such, efforts have been undertaken to develop a vaccine to prevent infection. Of these, Sm29 is a promising candidate that has been associated with resistance to infection/reinfection in humans and mice. Its ability to induce resistance to reinfection has also been recently demonstrated using a vaccine formulation containing Freund's adjuvant. However, Freund's adjuvant is unsuitable for use in human vaccines. We therefore evaluated the ability of Sm29 to induce protection against S. mansoni reinfection when formulated with either alum or MPLA as an adjuvant, both approved for human use. Our data demonstrate that, in contrast to Sm29 with MPLA, Sm29 with alum reduced parasite burden after reinfection compared to a control. We next investigated whether the immune response was involved in creating the differences between the protective (Sm29Alum) and non-protective (Sm29MPLA) vaccine formulations. We observed that both formulations induced a similar mixed-profile immune response, however, the Sm29 with alum formulation raised the levels of antibodies against Sm29. This suggests that there is an association between a reduction in worm burden and parasite-specific antibodies. In summary, our data show that Sm29 with an alum adjuvant can successfully protect against S. mansoni reinfection in mice, indicating a potentially effective vaccine formulation that could be applied in humans.
Assuntos
Antígenos de Helmintos/imunologia , Imunidade Humoral , Schistosoma mansoni/fisiologia , Esquistossomose mansoni/imunologia , Vacinas/imunologia , Adjuvantes Imunológicos/administração & dosagem , Adjuvantes Imunológicos/química , Compostos de Alúmen/administração & dosagem , Compostos de Alúmen/química , Animais , Anticorpos Anti-Helmínticos/sangue , Antígenos de Helmintos/química , Resistência à Doença , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , VacinaçãoRESUMO
The Surface Immunogenic Protein (SIP) of Group B Streptococcus (GBS) had been described as a good target for vaccine development. To date, SIP has been reported as a highly conserved protein, and in a mouse model it induces protection against lethal GBS challenge. Also, similar effects have been described by intranasal immunization with a SIP-based vaccine. In this study, we show the immune response induced by an oral SIP-based vaccine formulated on alum in a mouse model. Our vaccine can reduce vaginal GBS colonization and induce specific SIP-antibodies with opsonophagocytosis activities against GBS. Moreover, we observed the activation of T-cells producing IFN-γ, TNF-α, IL-10, IL-2, and increased expression of the transcription factor T-bet, suggesting a Th1-type humoral response. The oral SIP-based vaccine is a novel alternative in the development of a vaccine against GBS.
Assuntos
Antígenos de Bactérias/imunologia , Infecções Estreptocócicas/imunologia , Streptococcus agalactiae/imunologia , Vacinas/imunologia , Vagina/imunologia , Administração Oral , Compostos de Alúmen/administração & dosagem , Compostos de Alúmen/química , Animais , Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/química , Feminino , Células HL-60 , Humanos , Camundongos Endogâmicos C57BL , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/prevenção & controle , Streptococcus agalactiae/efeitos dos fármacos , Streptococcus agalactiae/fisiologia , Vacinação/métodos , Vacinas/administração & dosagem , Vacinas/química , Vagina/efeitos dos fármacos , Vagina/microbiologiaRESUMO
In this paper the environmental evaluation of the separation process of the microalgal biomass Scenedesmus sp. from full-scale photobioreactors was carried out at the Research and Development Nucleus for Sustainable Energy (NPDEAS), with different flocculants (iron sulfate - FeCl3, sodium hydroxide - NaOH, calcium hydroxide - Ca(OH)2 and aluminum sulphate Al2(SO4)3, by means of the life cycle assessment (LCA) methodology, using the SimaPro 7.3 software. Furthermore, the flocculation efficiency by means of optical density (OD) was also evaluated. The results indicated that FeCl3 and Al2(SO4)3 were highly effective for the recovery of microalgal biomass, greater than 95%. Though, when FeCl3 was used, there was an immediate change in color to the biomass after the orange colored salt was added, typical with the presence of iron, which may compromise the biomass use according to its purpose and Al2(SO4)3 is associated with the occurrence of Alzheimer's disease, restricting the application of biomass recovered through this process for nutritional purposes, for example. Therefore, it was observed that sodium hydroxide is an efficient flocculant, promoting recovery around 93.5% for the ideal concentration of 144 mg per liter. It had the best environmental profile among the compared flocculant agents, since it did not cause visible changes in the biomass or compromise its use and had less impact in relation to acidification, eutrophication, global warming and human toxicity, among others. Thus, the results indicate that it is important to consider both flocculation efficiency aspects and environmental impacts to identify the best flocculants on an industrial scale, to optimize the process, with lower amount of flocculant and obtain the maximum biomass recovery and decrease the impact on the extraction, production, treatment and reuse of these chemical compounds to the environment. However, more studies are needed in order to evaluate energy efficiency of the process coupled with other microalgal biomass recovery technologies. In addition, studies with natural flocculants, other polymers and changes in pH are also needed, as these are produced in a more sustainable way than synthetic organic polymers and have the potential to generate a biomass free of undesirable contaminants.
Assuntos
Técnicas de Cultura Celular por Lotes , Biomassa , Meio Ambiente , Microalgas/química , Fotobiorreatores , Scenedesmus/química , Compostos de Alúmen/química , Compostos de Alúmen/farmacologia , Técnicas de Cultura Celular por Lotes/instrumentação , Técnicas de Cultura Celular por Lotes/métodos , Poluentes Ambientais/isolamento & purificação , Reutilização de Equipamento , Floculação/efeitos dos fármacos , Química Verde/métodos , Humanos , Microalgas/efeitos dos fármacos , Fotobiorreatores/microbiologia , Scenedesmus/efeitos dos fármacos , Hidróxido de Sódio/química , Hidróxido de Sódio/farmacologiaRESUMO
Water treatment plants are designed to continuously produce drinkable water, meeting defined criteria of potability. However, besides potable water, these plants produce sludges that are disposed of in the environment. The present work aimed to evaluate the sludges generated in two water treatment plants and disposed of in the margin of the Juturnaíba dam. Since alum has been used as a flocculating agent in these two plants, the concentrations of aluminum were measured in the sludges and in surface sediments. The generated piles are extremely soft to walk on and difficult to measure, so indirect modeling procedures had to be applied. The calculated mass of the sludge piles at each plant are similar and respectively 60,370 and 61,479 tons. The aluminum content of the residues, calculated according to its dosage, was 33.2 and 32.6 g kg-1 in the piles from the two plants. The amount of alum dosed to the water corresponds almost to the excess of aluminum in the sludge, compared to the sediments. It was concluded that regardless of the fact that residues are disposed of in very restricted areas, they are directly in contact with the water and may constitute a threat for the environment and humans' health.
Assuntos
Compostos de Alúmen/análise , Sedimentos Geológicos/análise , Modelos Teóricos , Esgotos/análise , Instalações de Eliminação de Resíduos , Purificação da Água/métodos , Compostos de Alúmen/química , Brasil , Água Potável , Floculação , Sedimentos Geológicos/química , Esgotos/químicaRESUMO
The main objective of this study was to propose an improvement to the flocculation kinetics model presented by Argaman and Kaufman, by including a new term that accounts for the irreversible floc breakup process. Both models were fitted to the experimental results obtained with flocculation kinetics assays of low turbidity raw water containing Microcystis aeruginosa cells. Aluminum sulfate and ferric chloride were used as coagulants, and three distinct average velocity gradient (G) values were applied in the flocculation stage (20, 40 and 60â s-1). Experimental results suggest that the equilibrium between the aggregation and breakup process, as depicted by Argaman and Kaufman's original model, might not be constant over time, since the residual turbidity increased in various assays (phenomenon that was attributed to the irreversible floc breakup process). In the aluminum sulfate assays, the residual turbidity increase was visible when G = 20â s-1 (dosages of 60 and 80â mgâ L-1). For the ferric chloride assays, the phenomenon was noticed when G = 60â s-1 (dosages of 60 and 80â mgâ L-1). The proposed model presented a better fit to the experimental results, especially at higher coagulant dosages and/or higher values of average velocity gradient (G).
Assuntos
Floculação , Purificação da Água/métodos , Compostos de Alúmen/química , Cloretos/química , Coagulantes/química , Compostos Férricos/química , Cinética , MicrocystisRESUMO
Aluminum salts are used as coagulants in water treatment; however, the exposure to residual aluminum has been associated with human brain lesions. The water-soluble Moringa oleifera lectin (WSMoL), which is extracted with distilled water and isolated by chitin chromatography, has coagulant activity and is able to reduce the concentration of metal ions in aqueous solutions. This study evaluated the potential of using aluminum sulfate and WSMoL to reduce the turbidity and toxicity of water from the Cavouco stream located in Recife, Pernambuco, Brazil. The water sample used (called P1) was collected from the stream source, which was found to be strongly polluted based on physicochemical and water quality analyses, as well as ecotoxicity assays with Artemia salina and seeds of Eruca sativa and Lactuca sativa. The assays combining WSMoL and aluminum sulfate were more efficient than those that used these agents separately. Furthermore, the greatest reduction in turbidity (96.8%) was obtained with the treatment using aluminum sulfate followed by WSMoL, compared to when they were applied simultaneously (91.3%). In addition, aluminum sulfate followed by WSMoL treatment resulted in residual aluminum concentration (0.3 mg/L) that was much lower than that recorded after the treatment using only the salt (35.5 mg/L). The ecotoxicity of P1 was also strongly reduced after the treatments. In summary, the combined use of aluminum sulfate and WSMoL was efficient in promoting a strong reduction of turbidity and ecotoxicity of a polluted water sample, without resulting in a high residual aluminum concentration at the conclusion of the treatment.