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Studies on pulp and paper making characteristics of some Indian non-woody fibrous raw materials - Part II

Thu, 01 Jan 2004 00:00:00 GMT

Title: Studies on pulp and paper making characteristics of some Indian non-woody fibrous raw materials - Part II Authors: Dutt, Dharm; Upadhyaya, J S; Tyagi, C H; Malik, R S Abstract: Indian pulp and paper industries are facing an acute shortage of good quality of wood fibre with other associated problems. So they could not match their final product vis-a-vis to the finished products in globally competitive market. To overcome a serious lack of domestic wood fibres, morphological as well as chemical investigations on abundantly available and fast growing non-woody fibrous plants, which resemble in some aspects with softwoods and bamboo, have been undertaken. Keeping this challenge in view the pulp and paper making characteristics of three non-woody plants namely, Eulaliopsis binaia, Cajanus cajan, and Sesbania sesban have been studied extensively. Eulaliopsis binata, which is popularly known as ‘Sabai grass', consists of long leaf fibres. The fibre length of sabai grass is more than that of bamboo but fibre diam is 2.5-times lower than bamboo. Sabai grass consists of high cellulose and pectase with low lignin content. Sesbania sesban popularly known as 'Jainti' and consists of both bast and woody fibres. The rigidity coefficient, wall fraction and runkel ratio resembles that of bamboo, however the fibre length lies in the vicinity of fibre length of eucalyptus. Cajanus cajon shows higher degree of conformability within the sheet due to lower value of runkel ratio, slenderness ratio. wall fraction and rigidity coefficient and result in greater degree of fibre collapse and higher degree of conformability within the sheet. Page(s): 58-67

Studies on pulp and paper - making characteristics of some indian non-woody fibrous raw materials: Part 1

Thu, 01 Jan 2004 00:00:00 GMT

Title: Studies on pulp and paper - making characteristics of some indian non-woody fibrous raw materials: Part 1 Authors: Dutt, Dharm; Upadhyaya, J S; Malik, R S; Tyagi, C H Abstract: Indian pulp and paper industries are facing many problems in which availability of better quality of wood fibres is one of them. Hence the Indian pulp and paper industry could not match their final product vis-a-vis to the finished products in globally competitive market. Attempts are made to investigate the unique chemical and morphological characteristics of some potentially available non-woody fibrous plants that lie in close vicinity of softwood and bamboo in some properties that can be used to develop certain specific quality papers. In this paper industrial potential application of Ipomea carnea, Cannabis Jarivel and Sesbania aculeata, are discussed, in order to augment their utilization for manufacturing of high-quality cultural papers. Out of three, two non-woody plants are native of South America and Australia and are available in plenty in all the states of the India by adapting Indian climatic conditions. Ipomea carnea that is native to South America resembles with Pinus kesia and Picca abies in lumen and fibre diameter. Although the fibres are short, yet it gives stronger paper due to high collapsing index. Cannabis sativa, which is popularly known as 'true hemp', its long bast fiber strands or ribbons are extensively used for manufacturing of quality papers. Sesbania aculeata produces high quality bast fibers resembles with jute. Page(s): 48-57

Effect of drying methods on rehydration kinetics of potato slices

Sat, 01 May 2004 00:00:00 GMT

Title: Effect of drying methods on rehydration kinetics of potato slices Authors: Ghosh, U; Gangopadhyay, H Abstract: The effect of drying methods on rehydration kinetics of potato slices is investigated at (l0, 35, 60°C), respectively. The effective diffusion coefficients for water and solute are determined, assuming the rehydration process to be governed by fickian diffusion and the apparent moisture (Dew) and solute (Des) diffusion coefficients are calculated. The effect of temperatue on dew, can be interpreted according to Arrhenius law. Low temperature dehydration is found to improve the rehydration characteristics of potato slices. Page(s): 452-457

Adsorption of cadmium Ions from aqueous solution using different adsorbents

Sat, 01 May 2004 00:00:00 GMT

Title: Adsorption of cadmium Ions from aqueous solution using different adsorbents Authors: Meena, Ajay Kumar; Mishra, G. K.; Kumar, Satish; Rajagopal, Chitra; Nagar, P N Abstract: A comparative study on the adsorption of cadmium from aqueous solutions on a few low cost and locally available untreated and chemically treated adsorbents is carried out. Mustard husk, carbon aerogel and treated GAC are found to be most effective adsorbents in addition to treated GAC for the removal of cadmium from the aqueous solution solution at varying process parameters such as, pH (2-12) adsorbent dose (0.5-1.2 g/100 mL.), contact time (24-72 h) and initial cadmium concentration (1-5 rng/L). Treated GAC, carbon aerogel, and mustard husk show 100, 87 and 72 per cent adsorptive removal of cadmium, respectively, under optimized conditions of pH 4 and dosage 1 g/100 mL for 2 mg/L cadmium aqueous solutions in 48 h. The adsorption parameters are determined using both Langmuir and Freundlich isotherm models. Surface complexation and ion exchange are the major removal mechanisms involved. The adsorption isotherm studies indicate that the adsorption process is a monolayer coverage of cadmium on surface of treated GAC and fits into the Langmuir model. The adsorptive behaviour of cadmium on untreated mustard husk and carbon aerogel satisfies not only the Langmuir assumptions but also the Freundlich assumptions, i.e., multilayer formation on the surface of the adsorbent with an exponential distribution of site energy. The results of the experimental studies as well as the model parameters are presented. Page(s): 410-416