ABSTRACT
Treatment of effluents from animal slaughterhouse industries is indispensable, standing out coagulation/flocculation/sedimentation processes. Bionanoparticles (BioNPs) (nanoparticles (NPs) functionalized with Moringa extracts (MO)) were studied as an alternative natural coagulant that would contribute to the microbial load reduction, without increasing the treated effluent toxicity. MO extracts were prepared with different salts, and then, in a kinetics study, different NPs mass and coagulant dosages were evaluated. In the best-defined conditions, microbial load, toxicity tests for the bioindicator Lactuca sativa, and NPs reuse evaluation were performed. Removals of 96.14% turbidity and 43.63% UV254nm were achieved when using 500â mg L-1 of BioNPs containing 60â mg of NPs for every 20â mL of MO extract prepared with 0.1 M CaCl2. The BioNPs with an external magnetic field also decreased the sedimentation time from 140 to 10â min compared to MO, and the process efficiency did not expressively decrease after reusing the recovered NPs. Through toxicity tests, BioNPs were not considered to leave residuals toxic to the Lactuca sativa in the treated effluent. Besides, the microbial load reduction was 97.33% for heterotrophic microorganisms and total mesophiles and 99.25% for moulds/yeasts. Therefore, a satisfactory primary treatment was achieved, contributing to the sustainability of industries.
ABSTRACT
BACKGROUND: Currently, there is a great interest in cosmetics prepared on natural resources bases and this may restrict the use of synthetic substances. Plants play a relevant role as a source of biologically active natural products with cosmetic and dermatological importance. According to this context, polyphenolic extracts are highlighted because they have proven antioxidant, anti-inflammatory, anti-aging, antimicrobial, and supporting activity in solar photoprotection. AIMS: The purpose this study were reviewed at reporting the antioxidant activity of phenolic compounds, mainly applied to dermatological therapy, and highlighting the action mechanisms and structure-activity relationship. METHODOLOGY: In September 2017, we performed a literature search in PubMed and Scielo for scientific researches, antioxidant studies, and systemic reviews. The search terms we used were "PHYTOCOSMETICS" AND "ANTIOXIDANT ACTIVITY" OR "PHENOLIC COMPOUNDS" (from 2000). As inclusion criteria were used relevant original articles, scientific research in the area of interest, and crucial reference articles. Exclusion criteria were: duplicate publications, non-relevant articles and not published in English. RESULTS: The potential cosmetic application of phenolic compounds as natural antioxidants has been attributed to the chemical structure of these compounds, which to interfere in different phases of the oxidation mechanism. CONCLUSION: The use of phenolic extracts emerges as a viable alternative for cosmetic application, ensuring a commitment to sustainability. However, it is of crucial importance to evaluate the toxicity risks of raw materials and finished products.
