RESUMO
The objective of this study was the toxicity evaluation of landfill leachate samples both raw and after treatment by photo-Fenton (PF), biological (Bio) and photo-Fenton followed by biological (PF-Bio) processes. The organisms Artemia salina and Lactuca sativa were exposed to the leachate in different dilution. In the phytotoxicity evaluation, the inhibition of root (RGI) and radicle (RAGI) growth, and the number of germinated seeds (GR) were evaluated. In the ecotoxicity analysis, the 50% lethal dose (LD50) for each type of treatment was evaluated. The raw leachate, and after treatments PF, Bio and PF-Bio presented COD of 12,797, 1,347, 1,685, 220 mg/L and BOD5 of 4,251, 1,060, 692 and 89 mg/L, respectively. The GR was 0, 95, 25 and 40%, RGI was 100, 83, 100, 93%, whereas RAGI was 100, 72, 100 and 79% in the raw leachate and after treatments PF, Bio and PF-Bio, respectively. LD50 values of 0.25, 0.40, 0.38 and 0.54 were obtained for the raw effluent and after the PF, Bio and PF-Bio treatments, respectively. Smaller values of COD, BOD5, ecotoxicity and phytotoxicity were observed in the effluent after the PF-Bio treatment, indicating that this is the most environmentally suitable system for the treatment of landfill leachate.
Assuntos
Peróxido de Hidrogênio/química , Ferro/química , Esgotos/microbiologia , Poluentes Químicos da Água/toxicidade , Purificação da Água/métodos , Animais , Artemia/efeitos dos fármacos , Fenômenos Biológicos , Relação Dose-Resposta a Droga , Dose Letal Mediana , Lactuca/efeitos dos fármacos , Oxirredução , Processos Fotoquímicos , Testes de ToxicidadeRESUMO
In this work, the improvement on the concentrated grape juice physico-chemical characteristics by using an enzymatic treatment followed by Membrane Separation Process (MSP) has been investigated. By using Novozym 33095(r) and Ultrazym AFP L(r) enzymes varying three operating parameters, the best result on the grape pulp characteristics was attained for the Novozym 33095(r) performed at 35oC, 15 min. and 50 mgL-1. In micro/ultra filtration processes after enzymatic pretreatment, the best performance of the MSP with high permeate flux value and suitable grape juice characteristics was attained using 0.05 mm membrane pore size, 1 bar pressure and 40 oC treatment temperature. When reverse osmosis process is operated at 40 bar and 40oC, high soluble solid and low turbidity values are attained. An enzymatic treatment along with MSP has shown an alternative and efficient grape juice processing system, being possible to extend to other foods.
Assuntos
Bebidas/análise , Filtração/métodos , Manipulação de Alimentos/métodos , Vitis , OsmoseRESUMO
In this work, the removal of reactive blue 5G (RB5G) dye using the drying biomass of banana pseudostem (BPS) was investigated. The characterization of BPS particles was performed. Improvement in the RB5G dye removal performance at the following sorption conditions was evidenced: pH 1, 30°C sorption temperature and 40 rpm shaking, regardless of the particle size range. Kinetic RB5G dye sorption data obtained at better conditions fit well in an Elovich model. A combined Langmuir-BET isotherm model provides a good representation of the RB5G dye equilibrium sorption data, which shows the evidence of a physical sorption process on the BPS surface. Based on the results, the removal of RB5G dye molecules by BPS is based on a physical sorption process.
Assuntos
Corantes/química , Corantes/isolamento & purificação , Musa/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Corantes/análise , Concentração de Íons de Hidrogênio , Resíduos Industriais , Poluentes Químicos da Água/análise , Purificação da Água/métodosRESUMO
An electro-coagulation laboratory scale system using aluminium plates electrodes was studied for the removal of organic and inorganic pollutants as a by-product from leather finishing industrial process. A fractional factorial 2(3) experimental design was applied in order to obtain optimal values of the system state variables. The electro-coagulation (EC) process efficiency was based on the chemical oxygen demand (COD), turbidity, total suspended solid, total fixed solid, total volatile solid, and chemical element concentration values. Analysis of variance (ANOVA) for final pH, total fixed solid (TFS), turbidity and Ca concentration have confirmed the predicted models by the experimental design within a 95% confidence level. The reactor working conditions close to real effluent pH (7.6) and electrolysis time in the range 30-45 min were enough to achieve the cost effective reduction factors of organic and inorganic pollutants' concentrations. An appreciable improvement in COD removal efficiency was obtained for electro-coagulation treatment. Finally, the technical-economical analysis results have clearly shown that the electro-coagulation method is very promising for industrial application.