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In this paper, on the basis of chemical mechanical pulp wastewater generation, the generation of the characteristics and chemical mechanical pulp DCS, hazards and control, Huatai BCTMP production line back to the water DCS characteristics were studied; through simulation experiments, the effects of recycled water slurry bleaching properties; through simulation experiments to study the characteristics of slurry before and after bleaching DCS change and reuse water the unbleached pulp bleached pulp DCS; final This paper discusses the pectinase treatment and chemical methods of chemical mechanical pulp DCS control, main contents and conclusions are summarized as follows: (1) back to the water DCS water samples, dissolved substances (Dissolved Substances referred to as DS) and its main constituent. DCS watery solids content of 12 g / L, of which 95% contribution by DS; ash content of about 4.2 g / L, of which 96% contribution by DS; DCS turbidity of the water samples by the colloidal substances (colloidal Substances referred to as CS) contribution cationic demand and conductivity contribution by the DS. By GC-MS identified MTBE (Methyl Tertiary Butyl Ether, MTBE) extract contains substances: succinic acid, styrene-acrylic acid, p-hydroxybenzoic acid, p-hydroxyphenylacetic acid, p-hydroxyphenyl propionic acid , azelaic acid, 14-alkoxy acid, 3,4,5 - trihydroxy-benzoic acid, 16-alkoxy acid, 18 alkanoic acid, 11 - octadecenoic acid, oleic acid, adipic acid bis (2 - ethyl hexyl) phthalate, bis (6 - methyl-heptyl) ester. Identified by GC the The methanolysis reactions: xylose, arabinose, glucose, galactose, galacturonic acid, mannose, p-hydroxybenzoic acid. (2) through simulation experiments, the effects of to reuse water slurry drift. The results show that the use of reuse water after bleaching pulp brightness, the strength of small wastewater COD value increased after bleaching. (3) through simulation experiments to study the impact of reuse water DCS unbleached pulp and bleached pulp. The results showed that brownstock DCS content reuse water from the growth of 0.22 g / L to 0.85 g / L, bleaching pulp DCS growth from 3.43 g / L to 4.21 g / L; the brownstock cation requirements (Cationic Demand referred to the CD value) from 36.32μeq / L growth to 124.89μeq / L, after bleaching pulp CD value from 873μeq / L growth to 998μeq / L; bleaching before and after DCS content and CD values change shows that the use of reuse water slurry DCS content and nature of the impact, but the bleaching process more DCS. GC identified by the brownstock MTBE extract containing substance was: malonic acid, glycerol, p-hydroxy benzoic acid, 14-alkoxy acid, dibutyl phthalate, and 16-alkoxy acid, 18-alkoxy acid, hexyl diethyl-(2 - ethylhexyl) ester, phthalic acid bis (6 - methyl-heptyl) ester; bleaching pulp MTBE extract containing the substance: malonic acid, succinic acid, p-hydroxy benzoic acid, dioctyl ester of the hydroxy acid, azelaic acid, 14-alkoxy acid, 16-alkoxy acid, 18-alkoxy acid, 11 - octadecenoic acid, oleic acid, adipic acid, adipic acid bis (2 - ethyl- hexyl) ester, bis (6 - methyl-heptyl) phthalate esters; determined by GC the unbleached pulp methanolysis product: p-hydroxybenzoic acid, galactose, mannose, arabinose, xylose, ; after bleaching pulp methanolysis reactions are: p-hydroxy benzoic acid, galactose, arabinose, mannose, xylose, galactose, glucuronic acid, glucuronic acid. (4) pectinase, aluminum sulfate, cationic polyacrylamide deal with kind of the Huatai the BCTMP slurry DCS water. Pectinase enzyme activity is affected by temperature, pH value greater impact in the pH = 7.36, a temperature of 50 ° C, pectinase enzyme activity of 1250 U. Pectinase treatment the DCS water sample With the increase in the amount of enzyme, water samples CD value decreased to decrease the turbidity, COD value increased, the conductivity constant; when the processing time of 1 hour, the enzyme dosage of 100 U / L, when, DCS CD value of the water samples from 601μeq / L down to 465μeq / L, turbidity from 51 NTU reduced to 45.6 NTU the COD value rose from 2118 mg / L to 2348 mg / L. Aluminum sulfate processing DCS water samples, with the increase in the amount of aluminum sulfate, DCS turbidity of water samples first and then decreased, the conductivity increases, the COD value decreased, decreased pH value; when aluminum sulfate dosage of 0.7 g / L, CD almost down to zero, pH 4.57, for 8.23 NTU turbidity, COD of 1269 mg / L. CPAM processing in DCS water samples, with the increase in the amount of CPAM the DCS water sample turbidity decreased the CD value decreased, decreased COD value; when the CPAM dosage of 50 mg / L, DCS water samples CD of value 550μeq / L, turbidity to 17.9 NTU, COD value of 1904 mg / L.
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