Method for processing lignin-containing wastes from the paper industry to produce sorbents for wastewater treatmen
Y. I. Vaysman, I. S. Glushankova, E. S. Shirinkina, S. F. Davletova
Section: Ecologization of industry
Pulp and paper mill requires large amount of resources and energy. Technological processes of pulp and paper
mill are associated with high water consumption (10–20 m
3
per ton of final product) and high consumption of wood
raw materials and electricity (1080–1100 kg of raw materials and 300–350 kWh of electricity per ton of final product).
The most environmentally hazardous objects in pulp and paper mills are cellulose production, which is followed by
the formation of liquid waste – waste liquors containing lignosulfonates, the treatment of lignosulfonates is a compli
-
cated technological problem. Lignosulfonates are practically not subjected to biological degradation and the extraction
of liquor together with industrial wastewater into biological treatment facilities leads to a significant reduction in the
efficiency of water purification and increase contamination of hydrosphere objects. Despite the possibility of using liquid
lignosulfonates as surfactants, reagents for the preparation of drilling muds, a binder in the production of wood chipboards, fiberboards, the scale of their use is limited due to the volatility of the composition and structure of the waste. The
disposal of waste at landfill sites leads to long negative impacts on environmental objects, incineration of waste will be
followed by emissions of toxic substances and it would be necessary to use expensive waste gas purification technologies.
One of the directions of lignosulfonates treatment is their thermal destruction with the production of carbon sor
-
bents, which allows not only treating waste, but also obtaining cheap sorption materials for wastewater and gas emissions
treatment.
The paper presents the results of thermochemical pyrolysis process researches of lignosulfonates formed during the
production of cellulose from birch chips, the results of obtaining carbon sorbents, determining the main factors affecting
the yield of the sorbent, its physicochemical and sorption properties: the pyrolysis temperature, the processing time, the
ratio of lignosulfonate: hydroxide potassium. Determination of the sorbents porous structure parameters and the specific
surface was carried out on the basis of an analysis of nitrogen adsorption isotherms at a temperature of 77 K (-196
о
C)
obtained from the Quantum Hydrocarbon Analyzer NOVA 1200e and calculated using the metod BET (Brunauer, Em
-
mett and Teller) of the polymolecular adsorption theory and the Dubinin-Radushkevich eq
ISSN 1995-4301
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