RESUMO
Treatment of municipal landfill leachate by fixed TiO2 photocatalytic method was investigated in the present study using sunlight as light source. Indigenous TiO2 was immobilized with white cement. The leachate used in the study was collected from Kodungaiyur dumpsite in Chennai. Optimization of pH, catalyst dose and exposure time were carried out. Chemical Oxygen Demand (COD) was used to determine the degradation efficiency. The degradation efficiency of leachate was found to be 85% with a batch flat reactor under optimum condition. Fixed catalyst was found to be reusable for 5 times without any reduction in the efficiency. The degradation process was found to follow pseudo first order kinetics.
Assuntos
Catálise , Fotoquímica , Luz Solar , Titânio/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/químicaRESUMO
The recovery of anionic dyes Acid Red10 B (CI Acid Violet 54) and Acid Pink BE (CI Acid Red 183) in flat type supported liquid membrane (SLM) using tri-n-butyl phosphate as carrier was studied. The parameters studied were the effect of feed phase pH, stripping reagent concentration, string speed and initial dye concentration on permeability of dyes. The influence of salt concentration such as sodium chloride and sodium sulphate on the dye recovery was examined. The reusability of membrane and kinetics of transport were also studied. The optimum conditions of transport are feed phase pH 1 +/- 0.1, 0.1 M sodium hydroxide as stripping phase, stirring speed at 500 rpm. The maximum recovery under optimum conditions was observed as 94.2 % for Acid Red10 B and 85.7 % for Acid Pink BE. The maximum permeability was 11.0 x 10(-6) m/s for Acid Red10 B and 7.7 x 10(-6) m/s for Acid Pink BE.
Assuntos
Corantes/isolamento & purificação , Conservação dos Recursos Naturais/métodos , Concentração de Íons de Hidrogênio , Resíduos Industriais , Permeabilidade , Organofosfatos/química , Politetrafluoretileno/química , Cloreto de Sódio/química , Hidróxido de Sódio/química , Sulfatos/química , Indústria Têxtil , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/isolamento & purificaçãoRESUMO
Aqueous biphasic systems (ABS) are useful for the extraction of dye molecules from aqueous solution. Thus, they can be used in textile dye bath effluent treatment. The partitioning behavior of two commercially used textile dyes-Cibacron Scarlet LS 2G and Astacryl Red 3B were investigated in a TBAB-salt aqueous biphasic systems. It was found that all three salts, namely sodium chloride, sodium sulphate and sodium carbonate, investigated caused partitioning of dye into the upper TBAB rich phase. The efficiency of separation increased in the order NaCl < Na2SO4 < Na2CO. It was found that the cationic dye partitioned better than the anionic dye in the system. A concentration of 5 g/l of dye was extracted into the upper layer. Alteration of solution pH did not cause any significant difference in distribution ratios. Studies were extended to actual dye bath effluent and small scale up studies carried out. Efficiencies of removal obtained in all cases were extremely good with maximum efficiencies above 98 %.