The Prospects for Advanced Processing of Paper Sludge Using Enzymes, Microalgae and Yeast
Journal Title: Lesnoy Zhurnal (Russian Forestry Journal) - Year 2024, Vol 2, Issue 2
Abstract
This article presents the information on the valorization of waste generated during the production of tissue paper. The possibility of bioconversion of the polysaccharide part of paper sludge into simple sugars has been evaluated. The options for processing the paper sludge before enzymic hydrolysis to achieve the maximum yield of monosaccharides have been considered. Pretreatment with acids has been found to be a key step before the biocatalytic cleavage of waste polysaccharides. An additional yield of enzymic hydrolysis products after pretreatment with acids has been obtained by pre-extraction of the paper sludge with spirit or acetone. It has been established that the most intense enzymic hydrolysis of readily available fractions of the paper sludge takes place in the first 10â12 hours. Further, the process slows down, probably due to the action of the remaining components of the fillers, as well as an increase in the proportion of the difficult-to-hydrolyze polysaccharide part. In all cases, the proportion of absolutely dry non-hydrolyzed residue has been about 43±2 % of the dry matter of the paper sludge. The main products of enzymic hydrolysis have been glucose and xylose. The resulting sugars have been used for mixotrophic cultivation of the Tetradesmus obliquus and Chlorella vulgaris algae. Yeast strains have been selected for the conversion of monosaccharides from the paper sludge. In a series of experiments on non-sterile yeast cultivation, the Candida utilis PAL D and Debaryomyces hansenii SWING R cultures have turned out to be the most productive (within 2.10±0.14 g of air-dry yeast weight/dm3 per 24 hours). The degree of conversion of hydrolysate sugars has been 70±2 %. Most of the remaining sugars (about 80 %) have been represented by xylose. Complete utilization of the sugars has taken place on the 2nd day when having added an extra nitrogen source to the medium. On the other hand, the spent nutrient medium after yeast separation has been suitable for mixotrophic cultivation of microalgae. It has been revealed that the economic costs of pre-treatment of the paper sludge with nitric acid can be leveled by using the resulting salts as a nitrogen source for cultivating yeast. In doing so, the yield of yeast biomass increases by almost 2 times.
Authors and Affiliations
Dmytriy V. Tarabukin, Elena N. Patova, Irina V. Novakovskaya
Keywords
Related Articles
- EP ID EP734354
- DOI 10.37482/0536-1036-2024-2-166-177
- Views 12
- Downloads 0
Zoning of Catchments of Small Rivers in the South of the Volga Upland by the Water Protection Role of Forests
The article presents the results of the spatial distribution analysis of protective forest plantations within the catchment basins of in the south of the Volga Upland (within the Volgograd region). The data obtained are...
The use of flat rafting units during the Initia Timber rafting
The prohibition of drift floating used in the initial timber rafting led to an increase in the cost of supplying timber to consumers. Nowadays, the technology for rafting operations on small and medium-sized rivers is de...
Detritus Inside High Density Pine Stands in the Taiga Forest-Steppe Subzone of Central Siberia
At the present time, certain harmful effects are observed that affect forest ecosystems. They are forest fires, phytopathogenic activities, and invasive influence, in addition to changes in climatic conditions, in partic...
Mathematical Justification of Vehicular Traffic Resistance in Relation to Structural Surface Conditions of Hauling Roads
The currently available methods for evaluating technical-operational characteristics and conditions of hauling roads are time- consuming. Although, they provide a sufficiently accurate description of the conditions of ce...
Features of Designing Wooden Bridges of the Forest Complex
The supply of the national economy with forest resources is directly related to transport accessibility, the condition and development of the road network of forest-rich territories. Construction requirements for year-ro...