Biocoagulation of Direct Red-31 and Direct Yellow-12 Azo Dyes from Synthetic Wastew ater with Moringa Oleifera Seed Presscake

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.

Comparison between the Direct Dyeing Kinetics of Bamboo and Conventional Viscose Fibers

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.

Tourmaline activated persulfate for degradation of Sirius Türkis GL 01

The high Fe^(2+)content of tourmaline(TM)has potential of activating a persulfate reaction.However,information pertaining to using TM as an activator in persulfate oxidation process is currently unavailable.In this study,powdered TM was used to activate persulfate(PS)oxidation for decolorization synthetic direct azo dye,Sirius Türkis GL 01(STGL).Findings revealed that decolorization was significantly enhanced by TM/PS combined with ultrasound.A suitable oxidation condition for removal true color was TM 1.5 g/L,PS 5 *10^(-4)M,US 106 W/cm^2(20 min sonication at 20 kHz),and initial pH 6.0,which could completely remove the color and COD of 40 mg/L STGL after 20 min treatment.Oxidation condition under higher TM dosage with higher sonication power is beneficial for generation of sulfate radicals,consequently,promoting the oxidation performance of TM/PS process.Results clearly indicated that Fe-tourmaline,can be potentially used to activate PS oxidation for effective decolorization of wastewater containing direct azo dyes.

Color Fastness of Dyed Raw Linen Cloth Modified with Enzymes

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.