Review for "Discolouration of contaminated water with textile dye through a combined coagulation/flocculation and membrane separation process with different natural coagulants extracted from Moringa oleifera Lam . seeds"

Author(s):  
Maiara Luzia Grigoli OLIVIO ◽  
Elizângela Flávia Jacob ESTEVES ◽  
Dagmar Aparecida de Marco FERRO

Comumente o sulfato de alumínio é o coagulante químico utilizado nas Estações de Tratamentos para a clarificação da água, embora produza um lodo tóxico de difícil deposição no ambiente. No entanto, os coagulantes naturais como sementes de Moringa oleífera Lam. têm demonstrado vantagens para tratamento em comparação aos químicos, pela simplicidade de uso e baixo custo. O estudo objetivou analisar a eficiência coagulante da semente de Moringa oleífera na clarificação de água com turbidez e comparar com os parâmetros do coagulante químico sulfato de alumínio. As amostras de água foram coletadas no Córrego Jacu Queimado e as sementes colhidas em um plantio da própria espécie. Foram realizados, em laboratório, etapas sequenciais do experimento: comparação da eficiência da semente verde e seca, determinação da concentração e tempo de exposição da semente à água, comparação de agitação manual e magnética entre elas e do coagulante biológico com o químico, sendo analisados os aspectos físico, químico e biológico antes e após a adição de ambos. Observou-se que apenas a semente seca realiza a clarificação da água em comparação com os resultados das análises da água clarificada com o sulfato, determinando-se que 5 sementes são eficazes para tratar 1 litro de água com turbidez de até 25,0 NTU, considerando-se mais relevante a agitação manual para o efeito de coagulação e o aguardo de 2 horas para o término da decantação. Conclui-se, que a semente de Moringa é um coagulante biológico que se apresenta como alternativa para o tratamento de água com turbidez, porém, ainda não é indicada para a potabilidade. É preciso dar continuidade ao tratamento em busca de processos que visam melhorar a qualidade da água para aproximar-se aos parâmetros aceitáveis para o consumo humano.   Moringa oleífera Lam SEEDS: EFFICIENT USE OF BIOLOGICAL COAGULANT FOR WATER TURBIDITY TREATMENT, COMPARED TO ALUMINUM SULFATE CHEMICAL COAGULANT   ABSTRACT Aluminum sulfate is a chemical coagulant commonly used at Water Treatment Plants for water clarification, although it produces a toxic sludge of difficult deposition in the environment. However, natural coagulants such as Moringa oleíferaLam seeds have evidenced the advantages for the treatment when compared to chemicals, due to either their simplicity in and low cost.  This research aims at reviewing the efficient use of   Moringa oleífera seeds as coagulants for turbid water clarification as well as comparing the parameters of aluminum sulfate chemical coagulants. The water samples were collected at Córrego Jacu Queimado and the seeds were harvested from a crop of its own species. Sequential steps were performed in the lab for this experiment: Comparison of green and dry seeds efficiency, concentration and time of exposition of the seed to water measurements, comparison of manual and magnetic stirring among them and among biological and chemical coagulants, being analyzed physical, chemical and biological aspects before and after adding both of them. It was observed that only the dry seed enables water clarification when comparing the analysis results to sulfate water clarification, it was ascertained that 5 seeds are efficient to treat a liter of 25,0 NTU turbidity in water, considering as more relevant manual stirring for coagulation effect after a two-hour rest for decantation completion. It was concluded that Moringa seed is a biological coagulant presented as an alternative for turbid water treatment, although it is not indicated for drinkability. Further treatment is necessary in order to keep searching for processes that target to improve the quality of water and meeting acceptable parameters for water consumption.   Keywords: Biological Coagulant. Chemical Coagulant. Efficiency. Water Clarification. Comparative Parameters.


2020 ◽  
Vol 81 (2) ◽  
pp. 265-273 ◽  
Author(s):  
Fabiane Masala R. Silveira ◽  
Aline Takaoka A. Baptista ◽  
Tatiane V. Dutra ◽  
Benício Alves de Abreu Filho ◽  
Raquel G. Gomes ◽  
...  

Abstract Chemical products traditionally used in the disinfection of water bodies often pose human health risks. For this reason, studies on natural coagulants such as Moringa oleifera Lam. represent an alternative for the inactivation of pathogenic microorganisms, among which is Escherichia coli. This study evaluated the effect of different concentrations of coagulants obtained from Moringa seed extracts and their protein fractions in the inactivation of E. coli during the coagulation/flocculation process. The coagulants studied were the aqueous extract, saline extract and protein fractions albumin and globulin, highlighting that the protein fractions were more effective on inactivating E. coli. The protein fraction globulin at a concentration of 10.0 mg L−1 showed bactericidal effects against E. coli within 18 min, whereas the albumin showed a bacteriostatic effect within 48 min because it isolated colonies in the sediment sample.


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