Copper and lead ion removal from wastewater using fava d'anta fodder (Dimorphandra gardneriana Tulasne).

The contamination of bodies of water by potentially hazardous elements has in recent decades become an environmental problem that poses serious risks to humans, fauna, flora and microbiota, compromising the quality of life of the present ecosystem. Therefore, effluents must be properly treated in a legally acceptable manner before their disposal in the environment. With this in mind, adsorption presents itself as an inexpensive efficient technique for the removal of potentially hazardous elements from effluents with excellent adsorption capacities when natural adsorbents are used. In this study, fava d'anta fodder was used in its crude and alkalinized form to remove Cu(II) and Pb(II) ions. Equilibrium studies were carried out using adsorption isotherms in batch systems with mono- and multi-elementary systems containing the two ions. The Langmuir and Freundlich models were applied to the isotherm studies, with the ions being better suited to the Langmuir model, with maximum adsorption capacities of 24.45 mg g-1 and 68.49 mg g-1 (crude form) and 11.12 mg g-1 and 35.34 mg g-1 (alkalinized form) in the mono-elementary system for Cu(II) and Pb(II) ions, respectively.

Statistical evaluation of analytical curves for quantification of pesticides in bananas.

The aim of this paper is to statistically validate the analytical curves of a chromatography method to identify and quantify azoxystrobin, difenoconazole and propiconazole residues in banana pulp, using QuEChERS and GC-SQ/MS. A matrix-matched calibration was used and analytical curves were estimated by weighted least squares regression (WLS), confirming heteroscedasticity for all compounds. Statistical tests were performed to confirm the quality adjustment of the proposed linear model. The correlation coefficient for azoxystrobin, difenoconazole and propiconazole were, respectively, 0.9985, 0.9966 and 0.9997 (concentration range: 0.05 and 2.0 mg kg-1). The limits of detection and quantification were, respectively, between 0.007 and 0.066 mg kg-1, and between 0.022 and 0.199 mg kg-1, below the maximum limits stipulated by Brazilian, American, and European legislation. Only difenoconazole had an insignificant matrix effect (6.8%). Thus, the weighted least squares method is shown to be a safe linear regression model, providing greater reliability of the results.

Evaluating the presence of pesticides in bananas: An integrative review.

INTRODUCTION: Pesticides are organic compounds widely used in modern agriculture, being relevant for helping plantations and increasing food production. The banana, a fruit with oriental origin, stands out for being widely produced in tropical and subtropical regions which, like other matrices, is susceptible to pest action. This review aims to evaluate the presence of pesticides in bananas according to Brazilian, European and Codex legislation. METHODS: Four databases, ScienceDirect, SciELO, PubMed and Springer, were used to find relevant articles in the literature addressing methods for the determination of pesticide residues in bananas using the terms "banana", "chromatography", "pesticides" and "determination". The search stages included reading abstracts and titles, reading the full text, extracting data and analyzing data from eligible articles. The search was restricted to original research articles published in English from 2008 to 2018. RESULTS: 404 articles were found from the initial research, with only 15 studies being considered eligible for this review. Mass spectrometry is the most widely used detection technique. 5 articles were seen to use a multiresidue method to analyze only bananas (pulp), and from these, only 2 studies used methods to analyze the pulp and peel. The articles analyzed 172 samples, with 59.3% of these being conducted in Europe, 32.5% being conducted in Asia and only 8.1% in South America. A total of 79.1%, 32.4% and 42.6% of samples were unsatisfactory according to the Brazilian, European and Codex legislation, respectively, with these samples being contaminated with pesticide residues. CONCLUSION: This review presents the scarcity of articles aimed at identifying pesticide residues in bananas and the urgency of checking the quality of the fruit that reaches the population. The MRLs allowed by different legislations have clear divergences that do not ensure the lowest concentration values that guarantee consumer safety.