Hybrid treatment system for remediation of sugarcane vinasse.

The sugar and alcohol industries provide promising alternative energy sources to replace the use of petroleum derivatives. Vinasse is a byproduct of the alcoholic fermentation of various raw materials, and is used in the fertirrigation of sugarcane plantations. However, its excessive use leads to many soil and groundwater related problems, including toxicity to living organisms, acidification of soil and water, accumulation of heavy metals, and contamination of groundwater. The use of integrated systems, such as stabilization, filtration, and phytoremediation, have attracted interest in the treatment of wastewater from various sources, as these highly effective biogeochemical systems can reduce the pollutant concentrations in wastewater, thereby reducing its adverse effects. The aim of this work was to develop a hybrid treatment system to optimize the physical and chemical characteristics of vinasse so that it can be used as fertilizer for crops with a lower pollution impact. The results of this study validated the effectiveness of the proposed system and demonstrated positive modifications of vinasse.

Toxicity evaluation of leached of sugarcane vinasse: Histopathology and immunostaining of cellular stress protein.

Sugarcane vinasse is a residue generated at a rate fifteen times greater than the ethanol production. Because of its high organic and micronutrient content, this residue is used as a fertilizer on sugarcane crops. However, when used in large quantities, vinasse can saturate the soil and contaminate nearby water resources by percolation and leaching. Given the proven toxic potential of in natura vinasse, the present study aimed to evaluate the toxic potential of leached sugarcane vinasse using Nile tilapia (Oreochromis niloticus) as a test organism. A bioassay was performed after vinasse percolation in laboratory soil columns. The bioassay included one control group containing fresh water and two treatment groups, the first exposed to a 2,5% dilution of leached of vinasse and the second to a 2,5% dilution of in natura vinasse. After exposure, histopathological analysis was performed in gills and livers, and the latter were labelled for HSP70 proteins. No significant changes were detected in the gills of the exposed fish. However, in the liver, both in natura and leached vinasse induced statistically significant histopathological changes. These changes include hydropic degeneration, cell boundary losses, pyknotic nuclei and cellular disorganization. HSP70 expression significant increase in liver of both treatment groups were observed, being higher for the in natura vinasse exposed group. Results suggested that both leached vinasse and in natura vinasse were toxic, its still able to provoke histological changes and induce the cytoprotective response in exposed fish liver, evidenced by a immunostaining of cellular stress proteins. Thus, in order to reduce its environmental impact, appropriated effluent disposal is essential.

Liver alterations in Oreochromis niloticus (Pisces) induced by insecticide imidacloprid: Histopathology and heat shock protein in situ localization.

Liver is very sensitive to environmental contaminants such as pesticides, it being the first target of toxicity of a substance. The objective of this study was to investigate the possible effects of the insecticide imidacloprid (IMI) on the liver of Oreochromis niloticus according concentrations used for growing sugarcane. A semi-quantitative analysis of histopathological alterations of IMI on liver was performed by light microscopy and cellular labeling of heat shock proteins (HSP70) by immunohistochemistry. The most common changes in liver at all concentrations of IMI were hydropic degeneration, pyknotic nuclei, and loss of cell limits. Steatosis and increased levels of HSP70 were detected in hepatocytes with the highest concentration of IMI. In conclusion, the tested concentrations of IMI induced histopathological changes in the liver of O. niloticus and active defence mechanisms to maintain the morphophysiological integrity of the liver. This insecticide has a toxicity potential for these fish, which is a non-target organism of its action.

Sugar cane vinasse in water bodies: impact assessed by liver histopathology in tilapia.

Aquatic ecosystems are the main receptors of toxic substances from human activities. With the increase in sugar cane production, vinasse - the main residue of ethanol production - is a potential contaminant of water resources, due to its high organic matter content. This study was aimed at evaluating the toxicity of vinasse by examining the liver of the fish Oreochromis niloticus exposed to different dilutions of sugar cane vinasse (1%, 2%, 5%, 5% and 10%) in laboratory bioassays. Portions of liver were collected and fixed for histological and histochemical techniques to detect total proteins, polysaccharides and lipids. In the histological analysis, the groups treated with vinasse exhibited significant alterations, such as loss of cytoplasmic integrity, loss of cell limit and tissue disorganization. Protein and lipid profiles were not altered. Higher accumulation of polysaccharides was detected in fish exposed to lower concentrations of vinasse, with a gradual decrease in animals treated with vinasse in higher concentrations. We concluded that vinasse has a dose-dependent toxic and cytotoxic potential in water bodies and that the liver is strongly affected when acutely exposed to this contaminant.