Two direct dyes were applied to conventional viscose(CV)and bamboo viscose(BV)fibers,which were prepared from bamboo cellulose pulps,and the dyeing kinetics of two fibers were compared.Three kinetic equations,namely C...Two direct dyes were applied to conventional viscose(CV)and bamboo viscose(BV)fibers,which were prepared from bamboo cellulose pulps,and the dyeing kinetics of two fibers were compared.Three kinetic equations,namely Chrastil,Cegarra-Puente,and Vickerstaff,were used to fit the experimental dyeing rate points,showing that the best result was obtained by the Chrastil equation.BV fibers displayed slightly higher dyeing rates and dye adsorption values at initial stages,but a bit lower dye adsorption values at equilibrium than CV fibers.Furthermore,the dyeing of BV fibers exhibited lower activation energies and higher dyeing rate constants than that of CV fibers,and therefore showed slightly lower dependence on temperature.展开更多
Batches experiments were carried out to study the removal potentials of Moringa oleifera seed presscake( MOSP),the residual solids of Moringa oleifera seed after oil extraction used as a natural coagulant for the remo...Batches experiments were carried out to study the removal potentials of Moringa oleifera seed presscake( MOSP),the residual solids of Moringa oleifera seed after oil extraction used as a natural coagulant for the removal of two direct azo dyes including Direct Red-31( DR-31) and Direct Yellow-12( DY-12). The results indicated that the MOSP contained active proteins which were active agents and efficient for the removal of the two dyes. Higher temperature and lower p H were favorable for dye removal. The removal rates of the two dyes increased with the increasing MOSP dosage. Inorganic salts improved the dye removal efficiencies by the salt-in effect that prompted the release of proteins from the MOSP particles. Suspended solid simulated by kaolin decreased the dye removal efficiencies because of the competition for active sites of the MOSP between the kaolin particles and the dye molecules. The most likely mechanism for the removal of the two dyes by using MOSP as coagulant was a combined effect of adsorption and neutralisation of charges and the nucleation of the MOSP particles. The results provide new insight into the MOSP utilization and development of new coagulant for dye removal.展开更多
Influence of common dye-bath additives, namely sodium chloride, ammonium sulphate,urea, acetic acid and citric acid, on the reductive decolouration of Direct Green 1 dye in the presence of Fe0 was investigated. Organi...Influence of common dye-bath additives, namely sodium chloride, ammonium sulphate,urea, acetic acid and citric acid, on the reductive decolouration of Direct Green 1 dye in the presence of Fe0 was investigated. Organic acids improved dye reduction by augmenting Fe0 corrosion, with acetic acid performing better than citric acid. Na Cl enhanced the reduction rate by its ‘salting out’ effect on the bulk solution and by Cl-anion-mediated pitting corrosion of iron surface.（NH4）2SO4induced ‘salting out’ effect accompanied by enhanced iron corrosion by SO42-anion and buffering effect of NH4＋ improved the reduction rates.However, at 2 g/L（NH4）2SO4concentration, complexating of SO42-with iron oxides decreased Fe0 reactivity. Urea severely compromised the reduction reaction, onus to its chaotropic and‘salting in’ effect in solution, and due to it masking the Fe0 surface. Decolouration obeyed biphasic reduction kinetics（R2〉 0.993 in all the cases） exhibiting an initial rapid phase,when more than 95% dye reduction was observed, preceding a tedious phase. Maximum rapid phase reduction rate of 0.955/min was observed at p H 2 in the co-presence of all dye-bath constituents. The developed biphasic model reckoned the influence of each dye-bath additive on decolouration and simulated well with the experimental data obtained at pH 2.展开更多
Green thinking looks to develop alternatives with higher environmental advantage that traditional materials or processes. The present experimental studies are directed to investigation of dyeing the linen fabric prepa...Green thinking looks to develop alternatives with higher environmental advantage that traditional materials or processes. The present experimental studies are directed to investigation of dyeing the linen fabric prepared with modification with enzymes. In the research, 1% and 2% solution of cellulase enzyme Beizym ENC-SB （garment auxiliary of enzymes mixture of CHT R. BEITLICH GmbH/BEZEMA AG） and pectinase Beisol PRO （enzymes mixture for cleaning cellulose fibers of CHT R. BE1TLICH GmbH） enzyme solutions were used. The main objective of this work is focus on results studies of enzyme influence on dyeing of flax fabric with direct Solphenyl dye triade Blue FGLE （economical, fairly good light fast blue, main trichromatic component for medium shades with high wash fastness）, Scarlet BNLE （economical scarlet, main trichromatic component for medium to dark shades） 200%, and Yellow GLE （very bright neutral yellow, main trichromatic component for high wash fastness requirements）. The dye-bath exhaustion, color fastness to rubbing and washing were estimated. The color parameters before and after tests were calculated.展开更多
The degradation and decolourization of direct dye(Everdirect supra turguoise blue,FBL),acidic dye(Isolan orange S-RL) and vat dye(Indanthren red FBB) have been investigated by solar/TiO2 process.The effects of solutio...The degradation and decolourization of direct dye(Everdirect supra turguoise blue,FBL),acidic dye(Isolan orange S-RL) and vat dye(Indanthren red FBB) have been investigated by solar/TiO2 process.The effects of solution pH,dye concentration,dosage of TiO2 and nano-size of TiO2 have been studied.The increase in initial pH(3,5 and 11) and dye concentration decrease the removal rate.The treatment for FBB and FBL dye solutions is more efficient than that of S-RL.Under optimum conditions,the color removal is found to be almost complete for FBB and FBL while that of S-RL also reaches 95%.Langmuir adsorption isotherm and modified Langmuir-Hinshelwood kinetic model(L-H model) have been fitted to the experimental data and found to correlate the adsorption patterns as well as the kinetics of the dyes studied.展开更多
基金National Key Technology R&D Program of the Chinese Ministry of Science and Technology,China(No.2007BAE41B04)
文摘Two direct dyes were applied to conventional viscose(CV)and bamboo viscose(BV)fibers,which were prepared from bamboo cellulose pulps,and the dyeing kinetics of two fibers were compared.Three kinetic equations,namely Chrastil,Cegarra-Puente,and Vickerstaff,were used to fit the experimental dyeing rate points,showing that the best result was obtained by the Chrastil equation.BV fibers displayed slightly higher dyeing rates and dye adsorption values at initial stages,but a bit lower dye adsorption values at equilibrium than CV fibers.Furthermore,the dyeing of BV fibers exhibited lower activation energies and higher dyeing rate constants than that of CV fibers,and therefore showed slightly lower dependence on temperature.
基金the Research and Demonstration of Key Technology of Pollution Control for Heavily Polluting Industries in the Upper and Middle Reaches of Shaying River,China(No.2009ZX07210-002)The Opening Fund of State Key Laboratory of Pollution Control&Resource Reuse of Nanjing University,China(No.PCRRF12016)
文摘Batches experiments were carried out to study the removal potentials of Moringa oleifera seed presscake( MOSP),the residual solids of Moringa oleifera seed after oil extraction used as a natural coagulant for the removal of two direct azo dyes including Direct Red-31( DR-31) and Direct Yellow-12( DY-12). The results indicated that the MOSP contained active proteins which were active agents and efficient for the removal of the two dyes. Higher temperature and lower p H were favorable for dye removal. The removal rates of the two dyes increased with the increasing MOSP dosage. Inorganic salts improved the dye removal efficiencies by the salt-in effect that prompted the release of proteins from the MOSP particles. Suspended solid simulated by kaolin decreased the dye removal efficiencies because of the competition for active sites of the MOSP between the kaolin particles and the dye molecules. The most likely mechanism for the removal of the two dyes by using MOSP as coagulant was a combined effect of adsorption and neutralisation of charges and the nucleation of the MOSP particles. The results provide new insight into the MOSP utilization and development of new coagulant for dye removal.
文摘Influence of common dye-bath additives, namely sodium chloride, ammonium sulphate,urea, acetic acid and citric acid, on the reductive decolouration of Direct Green 1 dye in the presence of Fe0 was investigated. Organic acids improved dye reduction by augmenting Fe0 corrosion, with acetic acid performing better than citric acid. Na Cl enhanced the reduction rate by its ‘salting out’ effect on the bulk solution and by Cl-anion-mediated pitting corrosion of iron surface.（NH4）2SO4induced ‘salting out’ effect accompanied by enhanced iron corrosion by SO42-anion and buffering effect of NH4＋ improved the reduction rates.However, at 2 g/L（NH4）2SO4concentration, complexating of SO42-with iron oxides decreased Fe0 reactivity. Urea severely compromised the reduction reaction, onus to its chaotropic and‘salting in’ effect in solution, and due to it masking the Fe0 surface. Decolouration obeyed biphasic reduction kinetics（R2〉 0.993 in all the cases） exhibiting an initial rapid phase,when more than 95% dye reduction was observed, preceding a tedious phase. Maximum rapid phase reduction rate of 0.955/min was observed at p H 2 in the co-presence of all dye-bath constituents. The developed biphasic model reckoned the influence of each dye-bath additive on decolouration and simulated well with the experimental data obtained at pH 2.
文摘Green thinking looks to develop alternatives with higher environmental advantage that traditional materials or processes. The present experimental studies are directed to investigation of dyeing the linen fabric prepared with modification with enzymes. In the research, 1% and 2% solution of cellulase enzyme Beizym ENC-SB （garment auxiliary of enzymes mixture of CHT R. BEITLICH GmbH/BEZEMA AG） and pectinase Beisol PRO （enzymes mixture for cleaning cellulose fibers of CHT R. BE1TLICH GmbH） enzyme solutions were used. The main objective of this work is focus on results studies of enzyme influence on dyeing of flax fabric with direct Solphenyl dye triade Blue FGLE （economical, fairly good light fast blue, main trichromatic component for medium shades with high wash fastness）, Scarlet BNLE （economical scarlet, main trichromatic component for medium to dark shades） 200%, and Yellow GLE （very bright neutral yellow, main trichromatic component for high wash fastness requirements）. The dye-bath exhaustion, color fastness to rubbing and washing were estimated. The color parameters before and after tests were calculated.
文摘The degradation and decolourization of direct dye(Everdirect supra turguoise blue,FBL),acidic dye(Isolan orange S-RL) and vat dye(Indanthren red FBB) have been investigated by solar/TiO2 process.The effects of solution pH,dye concentration,dosage of TiO2 and nano-size of TiO2 have been studied.The increase in initial pH(3,5 and 11) and dye concentration decrease the removal rate.The treatment for FBB and FBL dye solutions is more efficient than that of S-RL.Under optimum conditions,the color removal is found to be almost complete for FBB and FBL while that of S-RL also reaches 95%.Langmuir adsorption isotherm and modified Langmuir-Hinshelwood kinetic model(L-H model) have been fitted to the experimental data and found to correlate the adsorption patterns as well as the kinetics of the dyes studied.
