Development of Physical and Chemical Processes to Increase the Efficiency of Concentration of Vinasse＇s Solids

Each year, ethanol production is increasing in Brazil, consequently, the generation of byproducts as well. Among these, the vinasse stands out. With polluting power a hundred times greater than domestic sewage and high concentration of minerals, vinasse is generated in large volumes. Because of these characteristics, it is widely used in fertirrigation. However, it is composed of about 97% water, inflating the cost of the transport from the plant to the field. For these reasons, removing water from the vinasse and the consequent concentration of solids is an alternative management and application of this by-product. This project aimed to analyze the efficiency of various physical and chemical processes in the removal of water from the vinasse.

Factorial analysis of the effect of sugarbeet vinasses on agroecological indices in horticultural field

The impact on soil of applying sugarbeet vinasses （V） was analyzed through a field experiment in horticulture greenhouse, arranged in a 23 factorial design. Two levels of three independent variables--application of V, use of polyethylene cover （PC） on the soil. and soil depth （D）---on various dependent variables were studied. Vinasses favoured crop yield and reduced the number of Meloidogyne incognita juveniles in soil. The concentrations ofN. P and K increased with the interaction VxD, with PC also increasing N concentration. The amounts of humic acids and humin decreased with D; fulvic acid concentration increased with V, but decreased with the interaction VxPC. Soil physical factors were improved mainly with D and V. Aromaticity of humic acid-like fractions increased ~＇itb V. In general, V showed significant effects mainly on the topsoil, suggesting low leaching risks. The results indicate that the levels of the independent factors improving a group of variables were not the same that those contributing to another group. Therefore, their best combination should be determined for each scenario to achieve optimum agroecological performance.

The Weight of Environment Aspect in the Choice of Vinasse Processing with New Technology through Economic Assessment

Vinasse improper disposal can cause damages to the environment.Fertigation,concentration and digestion aerobic or anaerobic generating fuel gas are the main technologies for vinasse use.Such alternatives present different impact on the environment;however,the weight of environment aspect in the decision remains under discussion.In this paper,authors present a discussion and valuations of environmental aspects about the main technologies of vinasse treatments.First,authors elaborated questionnaires,consulting specialists about the environmental and economical aspect of decision for changing to more environmentally friend technologies.The answers strongly suggest that the decisions of companies are mainly motivates by economics issue,and changing the current technology would be possible only if IRR(Internal Rate of Return)remains around 25%-30%.Then,authors proposed and performed calculations for inserting environmental aspects in the economical evaluation of technologies.The environmental resources performed considering carbon credit,economy with mineral fertilizers and the cost avoided with environmental fines.Scenarios and sensitivity cases performed,presenting discussions about the weight of environmental aspect in technology choice.It is possible to propose government policies that can economically value environmental benefits,such as tax reductions for people using vehicles to RGN(Renewable Gas Natural)or the implementation of a green label for companies that use biogas or RGN in their production processes(green label can be a differential or an extra score for company in future public bids,for example).The results showed that environmental aspect impacts directly the NPV(Net Present Value)of each technology,which can lead even to positive financial returns to companies;however,depending on valuation of environmental resources.Considering the environmental feature in economic impacts,the best option is the use of anaerobic digestion to produce energy that reduces carbon dioxide emissions or anaerobic digestion to produce gas if considering environmental scenario with the government policy of exemption from the tax on the ownership of motor vehicles.From the point of view of the land and water,it is possible to value economically in qualitative aspects through sectoral governmental policies.

Synthesis of vinasse-dolomite nanocomposite biochar via a novel developed functionalization method to recover phosphate as a potential fertilizer substitute

The effectiveness of phosphate(P)removal from aqueous solutions was investigated by novel low-cost biochars synthesized from vinasse and functionalized with calcined dolomite.The vinasse-derived biochar,synthesized via pyrolysis at different temperatures,showed easy preparation and a large surface area.The novel vinasse biochar nanocomposites were prepared by adding dolomite to the vinasse biochars with different weight percentages(10,20 and 30%).The characteristics of the prepared materials were identified for further understanding of the inherent adsorption mechanism between P ions and vinasse biochars.Vinasse-dolomite nanocomposite was very effective in the adsorption of P species from aqueous media.The effect of the operational factors on Vinasse-dolomite nanocomposite was explored by applying response surface methodology(RSM).According to RSM results,the optimum condition was achieved to be contact time 90(min),250(mg/L)of P concentration and pH 7.Thermodynamic isotherm and kinetic studies were applied on experimental data to understand the adsorption behavior.The Vinasse-dolomite nanocomposite revealed preferential P species adsorption in the presence of co-existing anions.The P species could be recovered by 1.0 MHC 1 where the efficiency was not affected up to the fifth cycle.The P-loaded Vinasse-dolomite nanocomposite was successfully tested on a plant;it significantly improved its growth and proved its potency as a P-based fertilizer substitute.

Biodegradation of beet molasses vinasse by a mixed culture of micro organisms:Effect of aeration conditions and pH control

The effect of aeration conditions and pH control on the progress and efficiency of beet molasses vinasse biodegradation was investigated during four batch processes at 38°C with the mixed microbial culture composed of Bifidobacterium,Lactobacillus,Lactococcus,Streptococcus,Bacillus,Rhodopseudomonas,and Saccharomyces.The four processes were carried out in a shake flask with no pH control,an aerobic bioreactor without mixing with no pH control,and a stirred-tank reactor （STR） with aeration with and without pH control,respectively.All experiments were started with an initial pH 8.0.The highest efficiency of biodegradation was achieved through the processes conducted in the STR,where betaine （an organic pollutant occurring in beet molasses in very large quantities） was completely degraded by the microorganisms.The process with no pH control carried out in the STR produced the highest reduction in the following pollution measures：organic matter expressed as chemical oxygen demand determined by the dichromatic method ＋ theoretical COD of betaine （COD sum,85.5%）,total organic carbon （TOC,78.8%） and five-day biological oxygen demand （BOD 5,98.6%）.The process conditions applied in the shake flask experiments,as well as those used in the aerobic bioreactor without mixing,failed to provide complete betaine assimilation.As a consequence,reduction in COD sum,TOC and BOD 5 was approximately half that obtained with STR.

Effects of Biochar on the Emissions of Greenhouse Gases from Sugarcane Residues Applied to Soils

The sugar and bioethanol industry generate large amounts of filter cake and vinasse, residues that are applied to sugarcane fields as conditioners and organic fertilizers. However, these may be significant sources of greenhouse gases emissions to the atmosphere. This study assessed the impact of sugarcane straw biochar on the emissions of CO2, CH4and N2O promoted by filter cake and vinasse applied to soil, and its effects on the chemical properties and bacterial communities of a Typic Hapludox and a Quartzipsamment. A laboratory incubation was conducted for 100 days with both soils under five treatments: vinasse and filter cake amendment (FV), plus biochar at 10 (FV + B10), 20 (FV + B20) and 50 (FV + B50) Mg·ha-1, and a control. Soil pH, available P and exchangeable base contents increased with biochar added to sandy soil. Mineral N decreased with biochar addition to both soils. The FV treatment increased CO2 emissions by 5-fold and 2.4-fold in sandy and clayey soils, respectively, compared to the control. Moreover, FV +B10 increased CO2 emissions by 4% and 6.4% in sandy and clayey soils, respectively, compared to FV. Cumulative N2O emissions in FV were 537% and 125% higher in sandy and clayey soils, respectively, compared to the control. Nevertheless, increasing biochar amendment rates reduced N2O emissions from 24% to 34% in sandy soil, and from 14% to 56% in clayey soil. CH4 emissions were negligible. The effects of filter, vinasse and biochar amendments on soil amelioration were closely related to its buffering capacity. Temporal changes on bacterial community structure were more pronounced in the sandy soil compared to clayey, and indicated that N2O emission mitigation in clayey soil was directly related to biotic mechanisms, while abiotic mechanisms caused by biochar played a more important role in mitigating N2O emissions in sandy soil.

Water Use in Sugar and Ethanol Industry in the State of Sao Paulo(Southeast Brazil)

Brazil is the largest producer of ethanol from sugarcane in the world. While the ethanol industry is economically important to Brazil for several reasons, it also has a significant impact on the environment. Here we analyze the water consumptive use in the transformation of the feedstock (sugarcane) into ethanol and the impact of industrial byproduct effluents on water resources of the state of Sao Paulo, Brazil. Our estimates indicated that in the 2007-2008 harvest, 700 million m3 was withdrawn mainly from rivers and streams by 140 mills, and of this total 440 million m3 was consumed which yielded a water use of approximately 1.53 m3 ·water·tonˉ1 sugarcane or approximately 18 L·water·L-ˉ1 ethanol. At the same time, a total of 120 million m3 of vinasse by-product was produced in the state, equivalent to an organic load of approximately 3 billion kg·BOD during the harvest season or approximately 8 million kg·BOD·dˉ1. Although the water used by sugarcane mills has decreased in recent decades, it is still possible to further decrease the amount of water used by ethanol production. This would decrease the pressure on 1st order streams of the state from which most water is withdrawn. In addition, the enormous volume of vinasse production must be reduced because it exerts constant pressure on aquatic ecosystems, soil and groundwater due to the constant increase in the potassium (K) concentration in areas where it is used as a fertilizer.

Recycling Agave Bagasse of the Tequila Industry

This paper presents an overview of different handling systems and use of the agave bagasse. These systems have appeared from different research works always taking in account the environmental sustainability. It is mentioned that the agave bagasse can be used for animal feeding, for the elaboration of compound materials, as an element for agricultural and hydroponic vegetables cultivation purposes, and also as a means to treat biosolids, vinasses, and bagasses of slaughterhouses and tanneries.