Many nitrophenols tend to persist in the environment and they may become public health hazards. Among nitrophenols, p-nitrophenol （PNP） is a priority pollutant that has been widely used as pesticide. PNP is a toxic ...Many nitrophenols tend to persist in the environment and they may become public health hazards. Among nitrophenols, p-nitrophenol （PNP） is a priority pollutant that has been widely used as pesticide. PNP is a toxic compound that enters the environment during manufacturing and processing of a variety of industrial products. This situation generalized its presence in multiple natural ecosystems： rivers, wastewaters, subterranean waters, soil treated by pesticides and urban atmosphere. This study aims to test the ability of wastewater microflora to degrade high concentration of PNP （500 rag/L） aerobically. An identification of the dominant microorganisms involved in the biodegradation is also carried. The cultures are performed using a minimum medium, where PNP is the sole source of carbon, energy and nitrogen. The kinetic of biodegradation is followed for more than 30 days of incubation at 30 ~C on a shaker （150 tours/min）. The obtained results show that more than 90% of PNP initial concentration is decomposed at the end of incubation. The isolation of microorganisms degrading PNP gave two bacterial colonies with different macroscopic aspects. Sequence analysis of 16S ribosomal DNA indicated that the PNP degrading isolates were closely related to members of the species： Pseudomonas aeruginosa and Bacillus cereus.展开更多
The effluents of textile dyes are highly colored, and disposal of the wastes into receiving waters cause damage to the environment, therefore dyes removal is of great importance. In this research, removal of Orange II...The effluents of textile dyes are highly colored, and disposal of the wastes into receiving waters cause damage to the environment, therefore dyes removal is of great importance. In this research, removal of Orange II, Remazol Blue, Methyl red, Malachite green and Safranin dyes by Pseudomonas fluorescens was studied in batch system as function of temperature, pH and initial dye concentration. The rate of removal dyes was studied by using pectrophotometer. The optimum value was determined as pH 7 for all dyes tested about 87.8-72.7%, and optimum temperature for removal of all tested dyes was 30℃ about 86.6-60.8%. Higher removal of dyes observed at 25 mL for all tested dyes about 91.9-72,7%. In general, the increase in dye concentration inhibited the growth of bacteria. Pseudomonasfluorescens showed higher removal of Orange II among the dyes tested.展开更多
文摘Many nitrophenols tend to persist in the environment and they may become public health hazards. Among nitrophenols, p-nitrophenol （PNP） is a priority pollutant that has been widely used as pesticide. PNP is a toxic compound that enters the environment during manufacturing and processing of a variety of industrial products. This situation generalized its presence in multiple natural ecosystems： rivers, wastewaters, subterranean waters, soil treated by pesticides and urban atmosphere. This study aims to test the ability of wastewater microflora to degrade high concentration of PNP （500 rag/L） aerobically. An identification of the dominant microorganisms involved in the biodegradation is also carried. The cultures are performed using a minimum medium, where PNP is the sole source of carbon, energy and nitrogen. The kinetic of biodegradation is followed for more than 30 days of incubation at 30 ~C on a shaker （150 tours/min）. The obtained results show that more than 90% of PNP initial concentration is decomposed at the end of incubation. The isolation of microorganisms degrading PNP gave two bacterial colonies with different macroscopic aspects. Sequence analysis of 16S ribosomal DNA indicated that the PNP degrading isolates were closely related to members of the species： Pseudomonas aeruginosa and Bacillus cereus.
文摘The effluents of textile dyes are highly colored, and disposal of the wastes into receiving waters cause damage to the environment, therefore dyes removal is of great importance. In this research, removal of Orange II, Remazol Blue, Methyl red, Malachite green and Safranin dyes by Pseudomonas fluorescens was studied in batch system as function of temperature, pH and initial dye concentration. The rate of removal dyes was studied by using pectrophotometer. The optimum value was determined as pH 7 for all dyes tested about 87.8-72.7%, and optimum temperature for removal of all tested dyes was 30℃ about 86.6-60.8%. Higher removal of dyes observed at 25 mL for all tested dyes about 91.9-72,7%. In general, the increase in dye concentration inhibited the growth of bacteria. Pseudomonasfluorescens showed higher removal of Orange II among the dyes tested.
