Ana Paula Serafini Immich

Removal of Remazol Blue RR dye from aqueous solutions with Neem leaves and evaluation of their acute toxicity with Daphnia magna

The removal of dyes present in industrial effluent has received great attention in the past few years. This is partly due to increasing environmental awareness and the implementation of ever stricter environmental rules. However, some treatments for color removal from these effluents do not guarantee the absence of other secondary toxic substances, often originating from the treatment process itself. The aim of this study is to evaluate the toxicity level of the adsorbent Neem, used in adsorption processes for color removal, as well as that of the dye solution before and after the adsorption process. The toxicity tests were carried out according to the Environment Agency FATMA regulation no. 017/02. They consisted of exposing representative microorganisms from the environment, for a certain time interval, to several concentrations of one or more substances, under different environmental conditions, and then evaluating the toxic effects. The results show that the Neem leaf extract had a harmful affect on the test organism used. Thus, it is recommended that the leaf extract is removed prior to effluent treatment, since the results of this study indicate that this will reduce the toxicity of the effluent and also improve the efficiency of the adsorption process.

Adsorption of Remazol Blue RR from Textile Effluents Using Azadirachta indica Leaf Powder as an Alternative Adsorbent

Adsorption is one of the techniques used for the effective removal of dyes from industrial effluents, but the adsorption efficiency depends on the choice of a suitable adsorbent. The aim of the present study was to investigate the use of Neem leaves as an alternative adsorbent for the removal of dyes present in textile effluents. The dyestuff studied was the reactive dye Remazol Blue RR. In order to obtain the best removal conditions, the influence of the following parameters was investigated: pH value of the aqueous solution, agitation, addition of sodium sulphate, temperature and adsorbent particle size. A good correlation was obtained when the Langmuir model was applied to fit the experimental data obtained for the concentration of solute adsorbed by the solid phase in terms of the equilibrium concentration of the fluid phase. The experimental data showed that 90% removal of Remazol Blue RR was achievable using Neem leaves as the adsorbent.

Improved tympanic membrane regeneration after myringoplastic surgery using an artificial biograft

Tympanic membrane perforations are due to common otologic problems. The current treatments to heal tympanic membrane perforation, such as myringoplasty, have some disadvantages, including the need for autologous grafting, which is rapidly absorbed by the organism before perforation recovery is complete. To improve the structural and functional tympanic membrane healing after surgery, we propose a new branch of artificial grafts. In this study, we report the development of artificial grafts using electrospun bioabsorbable polymers. Polymers such as poly (l-lactic acid) and poly (lactic-co-glycolic acid) acted as the scaffold for cell growth in a co-culture of fibroblasts and keratinocytes. This co-culture promoted the growth of an epithelial-equivalent tissue over the electrospun scaffold, which was used as an alternative graft in myringoplasty. The in vivo study was performed in Sprague Dawley rats. Ear endoscopy was performed 30days after surgery and showed that tympanic membrane perforations treated with artificial grafts healed naturally, completely and with the possibility of maintaining their actual functionality. In conclusion, our study described a new artificial graft created specifically to fulfill the requirements of perforated tympanic membrane healing processes, which are compatibility, proper durability and less intense side effects following myringoplasty.