CHEMISTRY OF STRAW BASED, CHEMI-THERMO-MECHANICAL PULPING BLACK LIQUOR AND ITS CHEMICAL AND BIOLOGICAL TREATMENT

Muhammad Ikram, . (2008) CHEMISTRY OF STRAW BASED, CHEMI-THERMO-MECHANICAL PULPING BLACK LIQUOR AND ITS CHEMICAL AND BIOLOGICAL TREATMENT. Doctoral thesis, College University, Lahore.

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Abstract

Pulping of non-wood raw materials available in abundance by Kraft, soda and chemi-thermo-mechanical processes produces good quality pulp in short processing time. As these process involve less chemical doses hence the present research work was designed for the chemical recovery from the black liquors to make the waste environment friendly. In the first step of the chemical recovery of the effluents, series of experiments were conducted to determine behavior and chemistry of this straw based black liquors. Chemical composition of the chemi-thermo-mechanical pulping black liquor was determined by fractional and composite sample analysis which showed extensively low dry solids andphysical and chemical properties of the black liquor tend to vary with organic to inorganic ratio of the solid contents. In the second step of the chemical recovery, desilication of the black and green liquors obtained from the chemi-thermo-mechanical pulping was conducted through the pH reduction by carbonation (80%) and sulphuric acid (85%). The green liquor sludge was found to be extremely high in COD, BOD with high reduction value. Sodium (95%) and sulphur (97%) were recovered from the sludge on dilution and addition of coagulating polymers. Second part of this thesis discusses treatment of the black liquor by chemical and/or microbiological means. In the chemical treatment process some flocculating and coagulating chemicals were employed. Addition of 200ppm alum, Buflok polymer 5425 (Buckmans) and setting of two hours yielded 82% COD reduction and solids in the range of 292ppm. Increase of alum to 1,000ppm and polymer dose of only 1ppm yielded similar results. The treatment of black liquor with hydrogen peroxide, ferric chloride, polyaluminium chloride (PAC), other flocculating polymers like HMW 110, HMW 130 by GEBetz and 8086 by BALCO gave no appreciable results.

Item Type: Thesis (Doctoral)
Uncontrolled Keywords: N/A
Subjects: Q Science > QA Mathematics
Depositing User: Unnamed user with email jmemon@hec.gov.pk
Date Deposited: 25 Jul 2017 06:38
Last Modified: 25 Jul 2017 06:38
URI: http://eprints.hec.gov.pk/id/eprint/3993

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