Dyes mostly used in the textile industry end up in their wastewater. The treatment of textile effluent has become necessary because of its associated environmental and health problems. In this study, five bacterial is...Dyes mostly used in the textile industry end up in their wastewater. The treatment of textile effluent has become necessary because of its associated environmental and health problems. In this study, five bacterial isolates were obtained from textile effluent. The isolated bacteria were used to decolourise effluent samples in a time-dependent manner and the change in colour was observed using an Ultraviolet-visible spectrophotometer. After 24 hours, decolourisation efficiencies of the five isolates were calculated and the highest decolourisation efficiency (78.5%) was observed with one of the isolates (E12). Isolate E23 recorded 64.7% followed by isolate E9 (62.0%) and E21 (53.7%). Isolate E19 had the lowest decolourisation efficiency (2.6%). The isolated bacteria were identified with E9 as <i>Aeromonas hydrophilia</i>, E12 as <i>Aeromonas hydrophilia</i>, E19 as <i>Pseudomonas aeruginosa</i>, E21 as <i>Aeromonas hydrophilia</i> and E23 as <i>Pseudomonas fluorescens</i>. To achieve a decolourisation efficiency of 78.5%, 25 ml of textile wastewater should be inoculated with 1 ml of the isolate (E12) culture. Thus, Isolate E12 (<i>Aeromonas hydrophilia</i>) is considered a promising candidate for biological textile wastewater treatment followed by isolate E23 (<i>Pseudomonas fluorescens</i>).展开更多
Armoracia rusticana is the commercial source of the enzyme Horseradish Peroxidase (HRP). Calcium ions play an important role in the functional conformation of HRP. The present study assesses the effect of three calciu...Armoracia rusticana is the commercial source of the enzyme Horseradish Peroxidase (HRP). Calcium ions play an important role in the functional conformation of HRP. The present study assesses the effect of three calcium salts viz., calcium chloride (CaCl2), calcium nitrate [Ca(NO3)2] and calcium sulphate (CaSO4) on the guaiacol activity of crude peroxidase extracted from the shoots and roots of in vitro grown plantlets of A. rusticana and their growth medium. The highest activity was observed in the shoot extracts of 25 mM CaCl2 treated plantlets (1.92 U/mL) and the root extracts of 25 mM Ca(NO3)2 supplemented plantlets (2.84 U/mL). The crude peroxidase activity of the medium containing 25 mM CaCl2 supplement was highest (0.13 U/mL). The capacity of the shoot and root extracts to decolourise a 10 ppm solution of methyl orange over 48 hours, was also tested. The decolourisation capacity was highest in the shoot extracts from CaCl2 treated plantlets (49.32%) and root extracts from Ca(NO3)2 treated plantlets (29.72%) respectively. Hence, the addition of calcium salts to growth medium enhances both peroxidase activity and decolourisation capacity of crude extracts of A. rusticana plantlets. These findings are of significance in enzymatic treatment for decolourisation of effluents containing dyestuffs.展开更多
In the present study, response surface methodology applying Doehlert experimental design was used to investigate decolourisation parameters of crude black shea butter. The decolourisation process was significantly inf...In the present study, response surface methodology applying Doehlert experimental design was used to investigate decolourisation parameters of crude black shea butter. The decolourisation process was significantly influenced by three independent parameters: contact time, decolourisation temperature and adsorbent dose. The responses of the process were oil loss, acid value, peroxide value and colour index. Contour plots of the decolourisation responses were superimposed and well defined the optimum zone. The optimum decolourisation conditions were found to be: contact time (30 min), temperature (72℃ - 95℃) and adsorbent dosage (1.5 - 2.5 mass %).展开更多
In this study, response surface methodology applying Doehlert experimental design was used to optimise decolourisation parameters of crude yellow shea butter. The decolourisation process was significantly influenced b...In this study, response surface methodology applying Doehlert experimental design was used to optimise decolourisation parameters of crude yellow shea butter. The decolourisation process was significantly influenced by three independent parameters: contact time, decolourisation temperature and adsorbent dose. The responses of the process were oil loss, acid value, peroxide value and colour index. Contour plots of the decolourisation responses were superimposed and well defined the optimum zone. The optimum decolourisation conditions were found to be: contact time (30 min), decolourisation temperature (80℃ - 95℃) and adsorbent dosage (1 - 2 mass%). These conditions gave decolourised shea butter with the following responses;oil loss (6.2% ± 0.2%), peroxide value (1.7 ± 0.1 meq O2/kg), colour (0.21 ± 0.05 Lovibond yellow) and acid value (25.6 ± 0.7 mg KOH/g).展开更多
在35℃温厌氧条件下,采用间歇批量实验法,通过测定不同体系中酸性橙Ⅱ(AO7)脱色情况,研究了氧化还原介体2-磺酸钠蒽醌(AQS)、2,6-二磺酸钠蒽醌(AQDS)、对苯醌(BQ)、核黄素(VB2)和硫堇(Thio)对厌氧脱色体系的影响.结果表明,QDS与AQS对染...在35℃温厌氧条件下,采用间歇批量实验法,通过测定不同体系中酸性橙Ⅱ(AO7)脱色情况,研究了氧化还原介体2-磺酸钠蒽醌(AQS)、2,6-二磺酸钠蒽醌(AQDS)、对苯醌(BQ)、核黄素(VB2)和硫堇(Thio)对厌氧脱色体系的影响.结果表明,QDS与AQS对染料降解的促进效果最佳,反应速率常数分别提高了199%和760%,BQ的反应速率常数仅提高了14.1%;当氧化还原介体投加浓度为0.1 m mol.L-1时,促进作用由大到小的排列顺序为:AQDS>AQS>VB2>Thio>BQ.促进效果因介体氧化还原电位、浓度、微生物种群结构的不同而有所差异.展开更多
文摘Dyes mostly used in the textile industry end up in their wastewater. The treatment of textile effluent has become necessary because of its associated environmental and health problems. In this study, five bacterial isolates were obtained from textile effluent. The isolated bacteria were used to decolourise effluent samples in a time-dependent manner and the change in colour was observed using an Ultraviolet-visible spectrophotometer. After 24 hours, decolourisation efficiencies of the five isolates were calculated and the highest decolourisation efficiency (78.5%) was observed with one of the isolates (E12). Isolate E23 recorded 64.7% followed by isolate E9 (62.0%) and E21 (53.7%). Isolate E19 had the lowest decolourisation efficiency (2.6%). The isolated bacteria were identified with E9 as <i>Aeromonas hydrophilia</i>, E12 as <i>Aeromonas hydrophilia</i>, E19 as <i>Pseudomonas aeruginosa</i>, E21 as <i>Aeromonas hydrophilia</i> and E23 as <i>Pseudomonas fluorescens</i>. To achieve a decolourisation efficiency of 78.5%, 25 ml of textile wastewater should be inoculated with 1 ml of the isolate (E12) culture. Thus, Isolate E12 (<i>Aeromonas hydrophilia</i>) is considered a promising candidate for biological textile wastewater treatment followed by isolate E23 (<i>Pseudomonas fluorescens</i>).
文摘Armoracia rusticana is the commercial source of the enzyme Horseradish Peroxidase (HRP). Calcium ions play an important role in the functional conformation of HRP. The present study assesses the effect of three calcium salts viz., calcium chloride (CaCl2), calcium nitrate [Ca(NO3)2] and calcium sulphate (CaSO4) on the guaiacol activity of crude peroxidase extracted from the shoots and roots of in vitro grown plantlets of A. rusticana and their growth medium. The highest activity was observed in the shoot extracts of 25 mM CaCl2 treated plantlets (1.92 U/mL) and the root extracts of 25 mM Ca(NO3)2 supplemented plantlets (2.84 U/mL). The crude peroxidase activity of the medium containing 25 mM CaCl2 supplement was highest (0.13 U/mL). The capacity of the shoot and root extracts to decolourise a 10 ppm solution of methyl orange over 48 hours, was also tested. The decolourisation capacity was highest in the shoot extracts from CaCl2 treated plantlets (49.32%) and root extracts from Ca(NO3)2 treated plantlets (29.72%) respectively. Hence, the addition of calcium salts to growth medium enhances both peroxidase activity and decolourisation capacity of crude extracts of A. rusticana plantlets. These findings are of significance in enzymatic treatment for decolourisation of effluents containing dyestuffs.
文摘In the present study, response surface methodology applying Doehlert experimental design was used to investigate decolourisation parameters of crude black shea butter. The decolourisation process was significantly influenced by three independent parameters: contact time, decolourisation temperature and adsorbent dose. The responses of the process were oil loss, acid value, peroxide value and colour index. Contour plots of the decolourisation responses were superimposed and well defined the optimum zone. The optimum decolourisation conditions were found to be: contact time (30 min), temperature (72℃ - 95℃) and adsorbent dosage (1.5 - 2.5 mass %).
文摘In this study, response surface methodology applying Doehlert experimental design was used to optimise decolourisation parameters of crude yellow shea butter. The decolourisation process was significantly influenced by three independent parameters: contact time, decolourisation temperature and adsorbent dose. The responses of the process were oil loss, acid value, peroxide value and colour index. Contour plots of the decolourisation responses were superimposed and well defined the optimum zone. The optimum decolourisation conditions were found to be: contact time (30 min), decolourisation temperature (80℃ - 95℃) and adsorbent dosage (1 - 2 mass%). These conditions gave decolourised shea butter with the following responses;oil loss (6.2% ± 0.2%), peroxide value (1.7 ± 0.1 meq O2/kg), colour (0.21 ± 0.05 Lovibond yellow) and acid value (25.6 ± 0.7 mg KOH/g).
文摘在35℃温厌氧条件下,采用间歇批量实验法,通过测定不同体系中酸性橙Ⅱ(AO7)脱色情况,研究了氧化还原介体2-磺酸钠蒽醌(AQS)、2,6-二磺酸钠蒽醌(AQDS)、对苯醌(BQ)、核黄素(VB2)和硫堇(Thio)对厌氧脱色体系的影响.结果表明,QDS与AQS对染料降解的促进效果最佳,反应速率常数分别提高了199%和760%,BQ的反应速率常数仅提高了14.1%;当氧化还原介体投加浓度为0.1 m mol.L-1时,促进作用由大到小的排列顺序为:AQDS>AQS>VB2>Thio>BQ.促进效果因介体氧化还原电位、浓度、微生物种群结构的不同而有所差异.
