حسین کرمانیان

Sticky contaminants represent one of the biggest technical challenges in the paper recycling process. These contaminants reduce paper strength, cause plugging of wires and felts, and stick to or deposit on machine parts affecting the runnability of the paper machine In this study, firstly, the sticky deposit of Docter blade dryer blades was subjected to multi-stage extraction with alcohol, aceton, toluene, and tetrahydrofuran solvents respectively. Then the nature of the resulting material and its physicochemical properties was investigated with FTIR analysis, GC-MS, TGA, XRF, SEM.. The results showed that the deposite originates from fiber, polymers such as polyvinyl acetate and styrene butadiene, which are components of hot melt adhesives, and fatty acid/resin esters. Fatty acids and resins are the most common organic compounds in stickies deposite. the possible origin of these compounds are chemical substances (saponified fatty acids), deinking steps and some resins and fatty acids used in the formulation of adhesives or more resistant resins and extractive materials related to Cellulose fibers. The observed minerals are mainly calcium, iron, silica and aluminum, which are present in the formulation of fillers and coating pigments during the papermaking process

Efficient approaches to eliminate or neutralize stickies is one of the topics of recent research. In the current study, some of the most conventional chemical and physical strategies in controlling these contaminants were compared. Control of micro-stickies originated from recycling of OCC using some selected physical approaches (washing, washing-flotation, flotation-washing and flotation) and some selected chemical methods by 4 fixing agents (Alum-PAC-pDADMAC-Cationic Starch) at 0.1-0.5-1 % dosing levels based on oven-dry weight of pulp were investigated. Electrical conductivity, TDS, turbidity, dissolved and colloidal substances (DCS) and COD were measured and compared to evaluate the efficiency of each approaches of micro- stickies removal. The results indicated that the lowest value of electrical conductivity and TDS in the physical methods was related to the flotation-washing stage and in the chemical methods was related to cationic starch 1%. The lowest amount of turbidity in the physical methods was observed in the washing and washing-flotation. Besides, the potential of secondary stickies was the lowest in the washing stage, while the flotation method had the highest potential of secondary stickies. Among the different dosing levels of the fixing agents, the lowest level of turbidity and DCS was determined for pDADMAC with 0.1% addition level, and the lowest amount of potential of secondary stickies was observed for Alum with 0.5% dosage. Both in the physical and chemical methods turbidity and DCS in pH4 was more than neutral pH. In the chemical approach with cationic starch dosage at 1% and in the physical method with the washing-flotation stage, the lowest amount of COD was reached

Petroleum compounds are major contributors to aquatic environmental pollution. In recent years, biological treatments as environmental-friendly and cost-effective techniques have been used alongside the various physico-chemical methods. Microbial cell immobilization in hydrogel carriers has been the focus of researchers due to various advantages such as ease of microbial species control, non-direct exposure of pollutants to the cells, increasing cell resistance during different types of stresses and reusability. The main goals of this study were introduction to electrospraying technique in order to size reduction of alginate beads and comparison of heavy crude oil biodegradation using an isolated strain of Bacillus licheniformis in free and immobilized cells.

The oil-degrading strain was isolated from oil-polluted site on Kharg Island. Microbial cells were examined in both free and immobilized systems under different conditions (pH=5,7) and initial crude oil concentration (1500,3500 ppm). Electrospraying technique was used for alginate beads production. Residual crude oil content was analyzed by gas chromatograph and gravimetrically method.

The maximum oil removal (61%) was obtained for the immobilized cells at a concentration of 3500 ppm in neutral medium. Overall, according to the results, after the 14th day, the biodegradation through the immobilized cells was significantly (p<0.05) higher than the free cells. Moreover, the cell immobilization caused the microorganisms to be more resistant to the harsh environments.

This study showed that the immobilized microbial cell system has a great potential for oil wastewater treatment. The electrospraying technique can be used to overcome to the mass transfer limitations.

Due to the hydrophilic nature of cellulose, nanofibrillated cellulose (NFC) is supplied in low solid content and high viscosity. As a cost saving strategy, increasing the possible highest solid content is preferred, which is hardly feasible owing to the irreversible hydrogen bonding formation during drying. This phenomenon known as Hornification prevents the cellulose nanofibrils to be readily dispersed in water after being dried. This research assessed an environmentally friendly procedure for the production of water-dispersible nanofibrillated cellulose powder based on carboxymethyl cellulose (CMC) absorption.

The absorption of varying amounts of CMC (0, 20 and 40 ml to constant 100 ml NFC) on cellulose nanofibrils in different temperatures of 22 °C (ambient) and 121 °C (autoclave) was investigated using conductometric titration. As the innovative part of the project, hydrodynamic properties of the dispersed NFC suspension including viscosity, turbidity, hydrodynamic specific volume, and water uptake were explored. Besides, the size of powder particles was probed by Dynamic Light Scattering (DLS).

The results indicated that in the highest addition level of CMC (40 ml) and autoclaving at 121 °C for 25 min, the highest absorption was observed, which yielded maximum results in all hydrodynamic properties compared to the control and other treated samples. On the contrary, data recorded for DLS signified that Poly Dispersity Index and the hydrodynamic diameter of the treated samples were bigger than untreated NFC, which was ascribed to the aggregation and agglomeration of cellulose particles in aqueous media.

Based on the method presented in this research, NFC powders with suitable dispersibility were obtained after oven-drying. It is concluded that the addition of adequate CMC to NFC results in increased dispersion and waster absorption capacity. The achievements of this novel method facilitates the production, handling, and storage of NFC in industrial applications.

Acid prehydrolysis aiming to remove hemicelluloses is one the key steps in producing dissolving pulp from wood resources. The objective of the present research is to resolve the necessity of using tis treatment in dissolving pulp production from old corrugated container. Therefore, temperature of 130 C, acid concentration of 1%, time of 30 min and liquor to paper of 7:1 were selected as acid pretreatment and the properties of both samples of with and without prehydrolysis were compared after cooking. The results showed that excluding reactivity, other dissolving pulp required properties including accessibility, degree of polymerization and the alpha cellulose content were diminished. Also, the results of yield and chemical composition indicated the destruction of this step to samples. Finally, regarding the superior properties of samples with no prehydrolysis and their acceptable value of reactivity, not only the acid prehydrolysis necessity was not acknowledged but also its application is not recommended.

Improvement the strength properties of papers made from recycled fibers is of important aims in papermaking industries. Current researches revealed that higher retention of strength induced additives through alternative absorption of polymers having opposite charge is one of promising approaches to obtain such purpose. In this study, treatment of fibers prepared from neutral sulfite semi-chemical papers with cationic starch and anionic CMC was conducted in pH~7, pH~10 and 0.001 M NaCl salty suspension. Then, fibers water retention value and zeta potential was measured. Standard handsheets with 60±3 g/m2 basis weight were made from untreated and treated pulps. The results have shown that fibers WRV significantly increased by absorbing of these two water-loving polymers. Consecutive changes of zeta potential confirmed charge reversion of fibers surface and sequential absorption of couple polymers. Scanning electron micrographs prepared from the samples of untreated and treated papers presented new variations in amount of fibers bend area due to the larger absorption of these two reinforcement polymers. Moreover, considerable development in paper mechanical characteristics (tensile, burst and tear indices) proved the success of high absorption of applied bio-polymers.

In this study, the liquorice root (Glycyrrhiza glabra) has been extracted in the Liquorice factory of Kerman, supplied as raw material. The above mentioned waste, after pre-hydrolyzed with sulfuric acid 2% at 130 °C in 60 minutes, is cooked at temperatures of 170 ̊C, the chemicals charge of 20%, and in four times 15, 30, 60 and 90 minutes and rate of liquor to waste 7:1 in Soda process. Obtained Soda pulps were evaluated in yield, lignin percentage, water retention value (WRV), viscosity and crystallinity. Results showed that by prolonging of cooking time, pulp yield and lignin percentage were decreased and WRV increased. Also, pulp viscosity in 30, 45 min was increased by increasing in cooking time that according to other results, it seems that it is false viscosity. In addition, accordance with characterizing of samples by XRD, by progressive cooking time from 15 to 45 min, sample crystallinity decreased and in 60 min its value is increased. According to the pulps viscosity and downward trend of lignin removal with progressive cooking time, this addition can be due to crystallization of hemicellulose like xylan on the crystalline zone of cellulose chain. Therefore, according to the results and based on Bio-refinery concept, cooking time 30 min suggested as the best option for production of high value-added products in saccharification process.

Paper made of recycled fibers has less strength compared to virgin fibers due to the multiplicity of recycling. Several solutions have been proposed to solve this problem consist of specialized enzymes application. While the applications of enzymes in the pulp and paper industry is still in the research and development stage, but some of them have pioneered the technology to operate. There are various methods to increase recycled fiber bonding and improves the paper strength. Oxidant enzymes such as cellulase and laccase are one of the methods that could accelerate delignification. Laccase-mediator system has the greatest effect on increasing of paper strength according to previous studies. Common Low molecular weight of mediator such as ABTS or HBT are the best non-phenolic lignin oxidizing that have been used yet. In order to increase the strength of recycled paper the effect of laccase treatment on old corrugated container (OCC) pulp was investigated in this study. OCC pulp was obtained from headbox of recycled paper factory in the north of Iran (Afrang Noor), and then was fractionated by Bauer-McNett classifier. HBT mediator was selected to treatment of OCC pulp by laccase. The pulp was treated by the enzyme in the adjusted conditions including consistency: 2%, pH: 5, reaction time: 2 hours, and reaction temperature: 60 °C in dosing levels of 0.005%, 0.01% , and 0.015 % based on oven-dried weight of pulp. Handsheet making and characteristic measurement carried out by TAPPI test methods and also statistical analysis was conducted using completely randomized design. Fiber classification result showed that fines constitute about 31% of weight of the pulp. There are significant differences at 1% level among the pulp strength properties of OCC which treated with laccase enzyme. Tensile and burst indices significantly were increased compared to the control using 0.005% of laccase. Multiple Duncan test showed that the average of these two indices by using 0.005% and 0.015% laccase (based on O.D. weight of pulp) had no significant difference and placed in the same statistical group. The variation trend of tear index unlike the other indices was observed and concora medium test (CMT) decreased at all levels of the treatments. OCC pulp treated with 0.005% laccase-HBT (based on O.D. weight of pulp) is recommended according to the important role of tensile and burst strength in test liner for packaging industry. Due to decreasing of Concora medium test (CMT) by the enzyme, laccase application is not suitable for making corrugated paper.

In this article, magnesium oxide (MgO) nanoparticles coated onto sawdust (SD) and its application as an efficient sorbent for removal of methylene blue dye has been reported. The introduced Nanocomposite was prepared through co-precipitation by addition of sawdust which has been previously soaked in magnesium sulfate solution into a NaOH solution. Adsorption studies was carried out in both batch and column systems. For determination of optimum dye removal conditions, the effect of parameters such as pH, initial dye concentration, sorbent dosage, contact time, and temperature were investigated in a batch adsorption system. The results indicated that SD/MgO nanocomposite is able for uptaking of methylene blue dye from aqueous solutions successfully. It was found that more than 95% dye removal is happened when 0.20 g adsorbent was treated with 100 mL of dye solution with initial concentration of 100 mg/L. The treatment of the data was also carried out using both Freundlich and Langmuir adsorption isotherms. Based on regression analysis, it was found that the sorption of methylene blue using nanocomposite of SD/MgO adopt Freundlich isotherm partially better than Langmuir isotherm. Maximum monolayer adsorption capacity has been obtained 59.17 mg/g. Kinetic studies have also been conducted and it was found that adsorption of methylene blue by SD/MgO follows with the pseudo-second-order kinetic model.

It was shown that the use of signaling molecules like nitric oxide donor sodium nitroprusside (SNP) can elevate phytoremediation potential of some plant species. The aim of the study is to reveal the effect of SNP on the enhancement of the phytoremediation potential and physiological responses of zinc-stressed safflower roots.
Material and The treatments were arranged in a completely randomized design with five replicates. After 10 days, the level of oxidative markers (e.g., H2O2 and lipid peroxidation) and antioxidant compounds (e.g., glutathione, ascorbate and phytochelatins) of plants were analyzed.
SNP application alleviated Zn-induced growth inhibition of roots probably through induction of some antioxidative compounds.Application of SNP resulted in decrease in oxidative markers and the activity of SOD as compared to the plants treated with Zn only. No relationship was found between SNP supplementation and glutathione and ascorbate levels, while upon application of SNP the level of PCs increased significantly.
The results suggest that the application of SNP render safflower roots more tolerant to zinc toxicity possibly through zinc chelation by the stimulation of phytochelatin production.

In recent years, the use of nano fibrillated cellulose (NFC) have been received a great attention. In this study, NFC cationized at three levels of 10, 20 and 30 wt% using 3-chloro-2-hydroxypropyl tri-methyl ammonium chloride (CHPTAC) and the cationic modification verified by Kjeldahl test. Then, the effects of the cationic nano fibrillated cellulose (CNFC) which were added to the bagasse pulp at four levels (0.1, 0.5, 1, and 2% based on OD pulp) on retention, drainage, and also the laboratory handsheet properties were assessed and compared with complex mechanism containing NFC (at the same addition levels of CNFC)/cationic starch (0.2, 0.4 and 0.6% based on OD pulp). The results showed that the type and amount of the additives have significant effects on all the optical and strength properties of paper. Using NFC, whether as unmodified together with cationic starch or as solely modified, made an increment in freeness and retention of the bagasse pulp and also, air permeance of the handsheet, and led to superior mechanical performance of CNFC in comparison with NFC/cationic starch. CNFC poses ionic bonding ability in addition to its hydrogen bonding, which in turn resulted in its more evenly distribution across the paper network and better performance as promoter biopolymer of paper. Furthermore, utilization of CNFC caused increment and NFC/cationic starch caused decline in brightness of paper, produced from bagasse pulp.

The use of cellulose at nanoscale has been greatly studied in the production of biological compounds due to its high strength, low weight and biodegradability. Nanostructures are synthesized through two mechanisms including top-down and bottom-up approaches. In this study, top-down partial dissolution was used as a simple and fast technique to produce nano cellulose. By controlling dissolution parameters such as time, the solvent interrupts the adjacent nanofibrils linking which is supplied through hydrogen bonds, and solves partially outer chains of nanofibril. During solvent rinsing, the partially dissolved chains re-solidified and welded each other, making consolidated structure in which the main components are undissolved native nanofibrils surrounded by cellulose type II and non-crystalline cellulose. Because of this, the final film was named nanopaper. This study considers the characteristics of fully biocompatible nanopaper directly produced from cotton linter fibers by partial dissolution method.
Refining the cotton linter fibers were done in three steps; pneumatic, washing with hot water followed by treating with sodium hydroxide. The handsheets were made by TAPPI standard method. The partial dissolution of papers with high content of alpha cellulose were done in the solvent N,N-dimethylacetamide/ 9% lithium chloride (DMAc/LiCL) and translucent cellulose nanopaper was obtained through pressing and drying the resulting gel. To evaluate the properties of the nanopaper, field emission scanning electron microscopy, X-ray diffraction, mechanical properties and thermal gravimetric analysis were used.
The diameter of undissolved nanofibrils in nanopaper fell between 60 and 66 nm. . Electron micrographs showed that nanopaper had more uniformity than paper. Visual transparency (back view) of nanopaper was significant due to the liberalization of cellulose nanostructures, the increase of uniformity and density, the loss of surface roughness and the increase of light transmission. The results of tensile properties showed that the nanopaper tensile stress was higher than that of paper. Paper and nanopaper tensile stress were 8.02 and 27.28 MPa, respectively and tensile modulus elasticity were 0.483 and 0.649 GPa, respectively. X-ray diffraction (XRD) of paper matched cellulose type I. During partial dissolution/re-solidification cellulose type II was appeared and non-crystalline phase increased judging from XRD data. The crystallinity degree of paper and nanopaper were measured 84.9 and 54.89%, respectively. The crystallite size of paper and nanopaper obtained 6.44 and 2.55 nm, respectively. The thermal stability of nanopaper was less than that of paper.
In nanopaper structure, undesolved cellulose type Iβ (undesolved nanofibrils) played reinforcing phase role, and cellulose type (II) and the amorphous cellulose formed the matrix phase. Partial dissolution destroyed part of the crystals and after solvent rinsing and re-solidification, some parts of the amorphous chains were rearranged to form crystals of cellulose type II. Finally, a tough translucent nanopaper was produced by creating consolidated nano structures. The reduction of cellulose crystallinity in nanopaper resulted in the loss of thermal stability in nanopaper.

This study was carried out in order to investigate the effects of different types of resins and also their mixtures on the impregnated paper properties. In this regard, pure urea resin (100%), mixture of melamine and urea resins with various combinations (60/40 and 70/30 and 50/50), mixture of nano-fiber cellulose ratios of 1, 2 and 3 percent with urea resin and pure PVA (100%) were used to impregnate of newsprint basic paper of Mazandaran wood and paper industries. Immersion of samples in the impregnation step were done in two time of 5 and 10 seconds. Next, melamine resin was used for surface coating and then absorption of resin in the impregnation and coating process measured. Results showed that in the impregnation step with pure urea (100%), in the respect of absorption rate and surface properties of melamine paper, the best time of impregnation was obtained 10 seconds. In the combined treatment, adding up to 30% melamine to urea resin, as impregnation step resin, offers better properties in terms of stain resistance, cigarette resistance, resistance to cracking and resistance to hot water steam for impregnatedmade paper. By adding nanocellulose up to 1% in impregnation resin, better properties is obtained for melamine paper. Also, PVA as impregnation resin, can be offer similar quality to pure urea in the resulting melamine papers.

Different factors influence on the properties of wood composite panels. Evaluating all of these factors not only increases waste of time and energy but also decreases accuracy in estimation of influence value of selected factors in manufacturing panels in order to obtain optimum point of different properties of wood composite panels. Hence, application of a new statistical method is necessary for determination of model estimating production´s optimum point. This study was aimed to evaluate the artificial neural networks performance to model the physical properties of the particleboard made of canola stalks particles. The physical properties of the particleboard were modeled and estimated using different weight ratios of melamine formaldehyde to urea formaldehyde, canola stalks to poplar particles and mat moisture content through MLP, RBFN and ANFIS artificial neural networks. The results showed that MLP neural network has better performance than RBFN and ANFIS neural networks to estimate the physical properties of the particleboard. The results also showed that the artificial intelligence models have a proper precision and ability to predict the particleboard's physical properties. The results of the sensitivity analysis also showed that for estimating and , the most important parameter was mat moisture content with a positive effect on the modeling, and melamine formaldehyde to urea formaldehyde ratio was also the most effective parameter for estimating and .

with respect to the special advantages of lignocellulosic materials, substitution of mineral reinforcement agents (fiber glass, asbestos and etc.) by organic-based fibers such as sisal, cellulosic fibers can be performed. However, using these natural fibers have some defects which could decrease curing and hardening speed of gypsum due to dissolution water-soluble extractives of fiber, while wood materials shortage in country, cheapness and abundance of lignocellulosic resources during the seasons of the year are some reasons of using agricultural waste. Hence, in this research the possibility of gypsum-bonded fiberboard production from bagasse, kenaf and synthetic fiber (fiber glass) was investigated.
any of bagasse fiber and kenaf fiber at three levels of 0, 7.5 and 15% (based on the dry weight of panels) and fiber glass at three levels of 0, 3 and 6% as effective variables on the physical and mechanical properties of gypsum-bonded fiberboard manufactured with gypsum to inorganic or organic fibers ratio of 1:2.75 and nominal density of 1.10g/cm3 were evaluated. Production methods of panels was semi-dry process. At first, water containing citric acid (99.50% water.5% acid) was sprayed on the dry fibers. After agitating fibers in the laboratory blender for 5min, gypsum was added to fibers and mixed together in blender with high circuit speed again. Then, admixture poured into the wood mould with dimension of 30×30 cm and pressed under cold press with pressure of 3MPa for 48 hours. After discharging, panels were treated at the fresh air condition for 5 days in order to climatization. Then, panels set in oven dryer with temperature of 50°C for 5 hours in order to complete hardening and reach to maximum strength. Drying the panels continued to 5-7% humidity. After ending manufacture process, physical and mechanical properties of panels tested and results was analyzed by response surface methodology based on second order polynomial regression model.
Finding: results showed that there is a good conformity between predicted and estimated values, so with increasing bagasse and kenaf fibers MOR and IB increased.
results of determination of hydration temperature and time of gypsum paste test showed that with increasing extractives of lignocellulosic materials temperature and hardening time of complex decreased and increased, respectively.

The old newsprint, as an important grade of waste papers, usually has been produced from chemicalmechanical pulp (CMP). Although the effect of paper aging on different properties of recycled pulp has been investigated from long time ago; but, few studies have been observed about the effect of this phenomenon on recycling of CMP paper. In this study, accelerated aging was applied on Hardwood CMP newspaper by 2 levels of temperature (50 and 100˚c) and 2 levels of time (24 and 48 hours). Results showed that accelerated aging applying 100˚c in 24 and 48 hours (about half of a decade and more) impose an intense reduction tensile strength, burst strength and tear strength indices as well as folding endurance strength of recycled pulp. Also, accelerated aging in 50˚c for 24 and 48 hours (about six months until one year) did not show any special effect on mentioned mechanical properties. Moreover, thermal accelerated aging didn’t have any significant effect on brightness of deinked CMP pulp. In general, it can be concluded that CMP waste papers less than one year old can preserve or even upgrade their mechanical properties after recycling, but aging more than half of a year will have detrimental effect on these properties

As renewable resources, agricultural wastes, such as bagasse, can be used as the raw materials for making cement-bonded particleboard (CBPB). Also for improving cement-bonded particleboard properties by increasing the hydration speed, methods such as water leaching and additives must be examined and used to eliminate or mitigate the effect of harmful substances and to increase the compatibility between organic material and cement. So, the present research is aimed at studying the effect of water-leaching treatment of bagasse and MgCl2 additive content on the properties of cement-bonded particleboard. According to many researchers, thermal treatment of wood creates dimensional stability, reduces the fiber's hydrophilicity and increases the strength of the boards by removing the negative effects of water soluble carbohydrates, hemicellulose and lignin on the hydration speed. Also according to the researches done by some researchers, adding catalysts to water and cement mixture can increase the hydration speed of the cement paste, and the compatibility between wood and lignocellulosic materials and cement is improved and cement hydration process is accelerated. In their research on the hydration speed of six wood species, it was showed that as hydration catalysts, MgCl2 and CaCl2 increase the speed of the process and improve the cement's curing time.
Materials used in this research include bagasse, Portland cement type II and MgCl2 additive. In this research, using Response Surface Methodology (RSM), the effect of water-leaching treatment and MgCl2 additive content on modulus of rupture (MOR), internal bonding (IB) strength, water absorption (WA) and thickness swelling (TS) of bagasse-based CBPB was examined. Quadratic models were developed to correlate the variables including water-leaching treatment (X1) and additive content (X2) to the dependent variables MOR, IB, WA and TS based on Central Composite Face design (CCF).
Findings: Analysis of variance (ANOVA) showed that hot water-leaching treatment improves the physical and mechanical properties more. Also, optimal condition for improving physical and mechanical properties using hot water-leaching treatment is to use 4.5% MgCl2 additive. In this condition, MOR, IB, WA and TS were 9 N/mm2, 0.3 N/mm2, 17.68% and 1.6%, respectively.
Due to its significance in the statistical analysis, the model presented by Response Surface Methodology provided a suitable and significant estimate to determine the application of the variables. According to the statistical analysis, the effect of water-leaching treatment and additive content on the physical and mechanical properties was significant at the level of confidence 99%.

In the current study, modification of NSSC pulp broke fibers was done by forming starch polymeric multilayers, using Layer-by-Layer (LbL) layering method. After fiber slushing and preparation of pulp suspension with 0.5% consistency and conductivity formation of about 437 µS/cm, adding water solution of 1 mM NaCl, the experiments of fibers treatment were conducted to build the polymeric layers (up to 5 consecutive layers). Afterward, water retention value (WRV) of fibers was calculated in samples to evaluate the influence of this method on fibers hydrophilicity. The fibers were then used to prepare standard handsheets (60±3g/m2) and the physical and strength properties of sheets were evaluated as a function of the number of layers deposited on the fibers. The results showed that the WRV index of the fibers was improved by the LbL treatment of NSSC broke pulp fibers, due to the increase in starch electrostatic absorption. Successive variation in paper apparent density increase and paper thickness decrease confirmed the construction of starch multilayers on the surface of broke fibers. Formation of such multilayers on broke fibers has led to considerable improvement in tensile index (from 13.21 N.m/g to 30.65 N.m/g) and burst index (from 1.23 kPa.m2/g to 2.36 kPa.m2/g). Also, the prepared SEM micrographs approve the sheet web compaction and paper mechanical improvement resulted due to an increase in inter-fiber bonding.

By Increasing demands on paper products and shortage of fiber resources, various strategies were introduced to meet the requirements. In this context, application of mineral fibers is a novel and growing approach. This study was aimed to Reduce the plant fibers by application of, mineral fiber in the papermaking system. Application of 0, 10, 20, and 30% Loadings of rock wool mineral fibers (RWMF) in incorporation with cationic starch (1%) on handsheet strengths, RWMF retention and total retention of stock were investigated. Results showed that bonding-dependent strengths, e.g. tensile and burst, were reduced by increasing the RWMF loading due to the low bonding ability of RWMF compared to the lignocellulosic fibers, while the tear index was increased up to 20% RWMF and declined then after due to higher intrinsic strength of the mineral fibers. Interwoven network creation of mineral-organic fibers during the sheet forming, enhanced the mineral and total retention value, however, despite priority of 30% over 20% substitution, there was no statistically meaningful differences. Therefore, with respect to severe reductions, the overall optimum substitution level of 20% for RWMF was reported in NSSC pulp production according to the obtained strengths results. In addition to economic and technical benefits derived from the mineral fiber application, the higher retention indirectly affects the environmental aspects such as reduction in suspended organic solids in process water, easier treatment of wastewater and lesser utilization of forest and other lignocellulosic fiber resources, all as the most important issues.

The effect of bleaching with sodium hypochlorite, as one of the most important parameters in obtaining optimal alpha cellulose pulp from cotton linter was studied. In this respect, unbleached cotton linter pulp was prepared from Parchin chemical industry co., bleached by HEA sequence in pH=9, 11 and 13; and then its chemical structures properties such as alpha cellulose, degree of polymerization, carbonyl groups, carboxyl groups, microkappa, ash content, acid insoluble materials and brightness were characterized. The lowest amount of alpha cellulose and lignin content were achived at pH=9,. Also, carbonyl and carboxyl groups were obtained in the highest level as well as sulfuric acid insoluble and ash content in this pH. By increasing of pH to 11, maximum amount of alpha cellulose and pulp brightness and also minnimum amount of ash content were obtained. In pH=13, less delignification was occurred while the lowest carboxyl groups were also observed in this pH. Therefore, according to results, pH=11 was suggested for industrial alpha cellulose production.

In this study, the liquorice root (Glycyrrhiza glabra) that was extracted in the factory in Kerman province, pre-hydrolyzed and then chemical compositions (Extractives, Lignin content, Holocellulose percent), the hydrolysis process yield and weight loss of the waste was measured. Pre-hydrolysis process was done on the above mentioned waste by hot water, hot water followed by 0.5 percent sulfuric acid and also alone sulfuric acid with different concentrations (0.5, 1, 1.5 and 2 percent) The samples were pre-hydrolyzed in hot water at 150 °C and 30, 60 and 90 minutes as well as in the mixture of hot water and 0.5 % sulfuric acid at 150 °C and 60 minutes and also in pure sulfuric acid, at 130 °C and at 60 minutes. The results showed that the pre-hydrolyzed treatment with hot water in 60 minutes had been favorable performance in the respect of weight loss, lignin content and holocellulose percent. Also, in the case of pre-treatment including sulfuric acid, 2% dose can be good selected option in term of maximum holocellulose percent and minimum lignin content so that it can be suggested to produce higher value-added products such as bioethanol from licorice root bid.

Upgrading recycled fiber properties has been a constant concern in pulp and paper industry. In this respect many researches has been applied. The present paper has been considered the effect of Amylase enzyme in pulping stage of old corrugated container (OCC). Also، pre-soaking of OCC (first step of pre-soaking for 6 hours in 3% consistency in different pH(s) and second step of pre-soaking at 60˚C for 18 hours with constant pH) in acid، neutral and alkaline pH on physical and mechanical properties (air resistence، tensile index، burst index، tear index and fold) of recycled paper and its effect on Amylase performance was investigated. Soaking itself improved mechanical properties. Alkaline pH pre-soaking had the most efficient effect on the mechanical properties. The results indicated that α-Amylase treatment improved the mechanical properties (except tear index) in the non-soaked samples but Amylase treatment had no significant effect on the soaked samples in the experimented pH ranges. The results showed that independent effects of soaking and alkaline treatments had superior effect on mechanical properties compared to enzymatic treatment. Statistically، none of treatments had significant effects on air resistence.

In this research، the influence of paper drying condition، as one of the most important variable in paper recycling، on the characteristics of fibers was studied. In this respect، bagasse soda pulp was collected from Pars Paper mill in Khozestan province and handsheets were made. The control hand sheet samples were dried at room temperature and the rest of the handsheets were dried using drum dryer set at 60° C for 3 hours، 100° C for 50 minutes and 120° C for 25 minutes to reach the same moisture content as the sheets dried at room temperature. Then، these handsheets were slushed in water and the pulp properties were determined. The results showed that with increasing the drying temperature، cellulose content did not change while hemicelluloses were reduced. Although the assessment of changing the lignin content with micro kappa method showed an increasing trend، but based on previous literature، it was concluded that the result are not justified. Also، the results indicated that changing the degree of polymerization and crystallinity did not show a consistent trend، showing initial reduction following by increased values. These results were attributed to interaction effect of drying temperature and time.

This study was carried out to provide improvement of recycled paper strength made from OCC. Chemical treatment of OCC pulp was carried out using 1% sodium chloride as ion exchange stage and then extraction by 3% and 5% sodium hydroxide based on oven dried pulp. Slurry temperature during the chemical reaction was adjusted to 25 and 70 °C. Handsheets were made based on a new standard method by KCL sheet former using a closed water system. Water retention value (WRV)، sheet density and strength were measured to characterize the treated fiber properties. No significant differences in WRV were found among control and treated pulps despite of maximum increasing of 25% applying 3% NaOH، ionic exchange and room temperature. The mentioned condition wasselected as the best condition which significantly improved apparent density، burst strength، tear strength and RCT.

This research was carried out to compare the paper properties from rice straw applying sodium and potassium based Chemimechanical pulping processes. Cooking conditions in potassium based pulping were adjusted as; potassium sulfite 6، 8، 10 and 12%، potassium hydroxide 3، 4، 5، 6، 8 and 12% on oven dry weight of rice straw، impregnation time; 30 minutes، liquid to rice straw ratio of 7:1، cooking time 30 and 60 minutes and cooking temperature 130، 150، 160، 165 and 170 oC. In sodium- based pulping، cooking conditions were selected as; sodium sulfite 6 and 8%، sodium hydroxide 3 and 4 % on oven dry weight of rice straw، impregnation time 30 minutes، liquid to rice straw ratio of 7:1، cooking time 30 minutes and cooking temperature 130 and 150 oC. The selected treatment in potassium based pulping showed the average total yield of 65. 19 and reject of 4. 22% and in sodium based pulping showed the average total yield of 69. 75 and reject percent of 3. 68. After refining the selected pulp to reach the freeness of 300±25 ml CSF، 60 g/m2 hand sheets were made and physical، mechanical and optical properties were measured. Results showed that the tensile strength index، breaking length and apparent density of paper made from potassium based process was similar to paper made from sodium based process. The papers made from potassium based process had higher burst strength index and brightness compared to sodium based process and papers made from sodium based process had higher tear index and higher K/S values than potassium based paper.