Sugarcane Bagasse Pulp Research Articles

Biocomposites of Bio-Polyethylene Reinforced with a Hydrothermal-Alkaline Sugarcane Bagasse Pulp and Coupled with a Bio-Based Compatibilizer

Bio-polyethylene (BioPE, derived from sugarcane), sugarcane bagasse pulp, and two compatibilizers (fossil and bio-based), were used to manufacture biocomposite filaments for 3D printing. Biocomposite filaments were manufactured and characterized in detail, including measurement of water absorption, mechanical properties, thermal stability and decomposition temperature (thermo-gravimetric analysis (TGA)). Differential scanning calorimetry (DSC) was performed to measure the glass transition temperature (Tg). Scanning electron microscopy (SEM) was applied to assess the fracture area of the filaments after mechanical testing. Increases of up to 10% in water absorption were measured for the samples with 40 wt% fibers and the fossil compatibilizer. The mechanical properties were improved by increasing the fraction of bagasse fibers from 0% to 20% and 40%. The suitability of the biocomposite filaments was tested for 3D printing, and some shapes were printed as demonstrators. Importantly, in a cradle-to-gate life cycle analysis of the biocomposites, we demonstrated that replacing fossil compatibilizer with a bio-based compatibilizer contributes to a reduction in CO2-eq emissions, and an increase in CO2 capture, achieving a CO2-eq storage of 2.12 kg CO2 eq/kg for the biocomposite containing 40% bagasse fibers and 6% bio-based compatibilizer.

Potential of pineapple wastes for Pectin recovery: A path towards waste valorization

Majority of agricultural wastes and crop residues like cereal brans, sugarcane bagasse, peels, pomace and sugar beet pulp act as the vital sources for natural production of biochemicals. The production of natural pectin from various agro-wastes can be focused as the major biotechnological tool taking much demand against the chemical production processes. Investigation was carried out for conversion of pineapple wastes towards isolation of pectin as a part of waste management. About 60% of total pineapple fruit is regards as waste in form of peel, core, pomace and crown. Maximum pectin was detected from pomace part of the pineapple.

Statistical Optimization of Biobleaching Efficacy of endo-β-1,4-xylanase from an Actinobacterium Streptomyces olivaceus (MSU3) in Comparison with Zinc Oxide Pretreated Sugarcane Bagasse Pulp Using Box–Behnken Design

ABSTRACT The bio-bleaching efficacy of endo-β-1,4-xylanase from an actinobacterium Streptomyces olivaceus (MSU3) was studied by using sugarcane bagasse pulp in comparison with chemical-mediated bleaching. Before that, the sugarcane bagasse pulp was processed with various concentrations of xylanase (20–100IU) and zinc oxide (0.2–1.0 g) individually through laboratory conditions. Simultaneously, both enzyme- and chemical-mediated bleaching process were optimized through response surface methodology by using the reaction condition containing pH 6.6, temperature 47°C with the incubation time of 3 h. The analysis of variance of the parameters expressed the maximum level of coefficient (R 2 = 0.963–0.996) with more significant (P < 0.0001). In bleaching process under-optimized conditions, the highest level of reducing sugar (110.02 mg/g), reduction of kappa number (14.69 k), degree of brightness (43.62%ISO), level of residual lignin (2.20%) with the discharge of phenolic (λ 237 = 0.119 OD), and hydrophobic (λ 465 = 0.046 OD) groups were attained in xylanase (80.0 IU) mediated bleaching than zinc oxide bleaching. Further, the effect of bleaching on processed pulp samples with loosening and changes of surface cell fiber was examined by field emission scanning electron microscopic analysis. The efficient fibrillation and porosity of pulp fiber were seen in xylanase bleached pulp than chemical-bleached pulp. These results clearly indicated that the endo-β-1,4-xylanase of the chosen actinobacterium could able to bleach the bagasse pulp effectively than the zinc oxide-mediated bleaching.

Production and Characterization of Paper from Pineapple Leaves and Sugarcane Bagasse Pulp

Paper is the final product resulted from compression of fiber suspension of cellulose pulp, which is derived from wood or non-woody material. In this study, paper was made from mixture of pineapple leaves and sugarcane bagasse pulp (P:S, 100:0%, 80:20%, 60:40%, 40:60%, 20:80%, and 0:100%) at varying cooking liquor or NaOH concentration (1.5% and 3%) using semi-mechanical soda pulping method. Pulp characterisation (kappa number, tensile and tearing strength) was further carried out to ensure a stable pulp and paper quality. Results showed that the highest tensile strength of 6,709 kN was obtained at pineapple leaves and sugarcane bagasse pulp composition of 100:0% and NaOH 3%, whereas the highest tearing strength (1730,13 mN) was observed at the P:S of 40:60% with similar concentration of NaOH. The lowest kappa number (6,182) was also obtained at P:S of 0:100% and 3% NaOH. The pulp characterisation values have fullfil SNI No. 6519:2016 quality standard for plastic laminated paper.

INFLUENCE OF USING SUGARCANE BAGASSE AND SUGAR BEET PULP WITH OR WITHOUT ENZYMES IN RABBIT DIETS: 1- ON GROWTH PERFORMANCE OF GROWING RABBITS

The aim of this study was to investigate the effect of using different levels of sugarcane bagasse (SCB) and sugar beet pulp (SBP) with or without enzyme in diets of growing APRI line rabbits on the productive performance. One hundred and forty-four APRI rabbits were divided randomly into nine experimental groups of 16 rabbits each (8 males + 8 females) of 5 weeks of age with an average live body weight of (723 ± 2 gm.), were used in this study. The following 9 diets were obtained: control (0% Sugarcane Bagasse and Sugar Beet Pulp), SCB50 diet (Sugarcane Bagasse replace to 50% Berseem hay), SCB100 diet (Sugarcane Bagasse replace to 100% Berseem hay), SCB50E diet (Sugarcane Bagasse replace to 50% Berseem hay with Kemzyme), SCB100E diet (Sugarcane Bagasse replace to 100% Berseem hay with Kemzyme), SBP50 diet (Sugar Beet Pulp replace to 50% Berseem hay), SBP100 diet (Sugar Beet Pulp replace to 100% Berseem hay), SBP50E diet (Sugar Beet Pulp replace to 50% Berseem hay with Kemzyme) and SBP100E diet (Sugar Beet Pulp replace to 100% Berseem hay with Kemzyme). All diets were nearly isonitrogenous, iso-caloric and contained similar levels of crude fiber and micro elements. Results indicated that there were no significant differences in body weight between rabbits fed SBP diet and rabbits fed control diet, while those fed SCB diet had the lowest body weight. Using Kemzyme increased the body weight insignificantly, except in weeks 10, 11 and 12, which Kemzyme significantly (P<0.05) increased body weight. During the whole experimental period (5-13 weeks of age), rabbits fed SCB diets recorded significantly the lower daily weight gain, as compared with those fed SBP and control diet (23.56 vs. 25.43 and 25.41 g, P<0.001, respectively). Supplementing Kemzyme in diets had no significant differences on daily weight gain in all experimental periods. Feed intake in the whole period (5-13 weeks of age) significantly decreased by 3.5 and 5.1% for rabbits fed SBP and SCB diets, respectively, as compared with those fed control diet. Moreover, feed intake was decreased by 1.95% with adding Kemzyme during the whole experimental period. Feed conversion ratio was significantly improved with rabbits fed SBP diets, as compared with those fed control diet. Moreover, rabbits fed diets supplemented with Kemzyme improved the feed conversion ratio by 3.36%, as compared with those fed diets without Kemzyme. No significant differences could be observed in mortality percentage due to fiber source (AL, SCB and SBP) or enzyme supplementation in diets.

Chemical-free thermomechanical pulping of empty fruit bunch and sugarcane bagasse

The biomass resources oil palm empty fruit bunch (EFB) and sugarcane bagasse, which are residues from the palm oil and sugar industries, continue to be investigated for more applications. With increasing concern for the environment, cleaner production has been a worldwide aim of researchers. In this study, thermomechanical pulp (TMP) from EFB and sugarcane bagasse was prepared with disc refining after steam pretreatment of the raw materials. Afterwards, refining and handsheet properties of TMP using various percentages of unbleached soda bagasse pulp (USBP) were studied. Fiber characterizations and handsheet properties showed that pulp of acceptable quality was obtained via thermomechanical pulping. Moreover, energy consumption during PFI refining of EFB TMP was higher than that of bagasse TMP. Physical properties were further enhanced through introduction of USBP. The results firmly support the feasibility of cleaner thermomechanical pulping of EFB and sugarcane bagasse.

Preparation and Characterization of Nanocomposite Films Containing Nano-Aluminum Nitride and Cellulose Nanofibrils.

Nanocomposites consisting of cellulose nanofibrils (CNFs) and nano-aluminum nitride (AlN) were prepared using a simple vacuum-assisted filtration process. Bleached sugarcane bagasse pulp was treated with potassium hydroxide and sodium chlorite, and was subsequently ultra-finely ground and homogenized to obtain CNFs. Film nanocomposites were prepared by mixing CNFs with various AlN amounts (0–20 wt.%). X-ray diffraction revealed that the crystal form of CNF-AlN nanocomposites was different to those of pure CNFs and AlN. The mechanical performance and thermal stability of the CNF-AlN nanocomposites were evaluated through mechanical tests and thermogravimetric analysis, respectively. The results showed that the CNF-AlN nanocomposites exhibited excellent mechanical and thermal stability, and represented a green renewable substrate material. This type of nanocomposite could present great potential for replacing traditional polymer substrates, and could provide creative opportunities for designing and fabricating high-performance portable electronics in the near future.

Investigation of deposit problem during sugarcane bagasse pulp molded tableware production

Abstract Formation of brown deposit is quite a common problem in hot pressing stage of cellulosic pulp molded tableware production, especially using bleached sugarcane bagasse pulp as raw material which blocks the pipes, corrodes and damages the equipment, increases the cleaning frequency and correspondingly increases the costs as well as reduces the quality of the products. In this work, the composition of the deposit was analyzed, and the effects of fines to the drainage and drying process of cellulosic pulp molded tableware production was studied by thermogravimetric analysis to investigate the cause of this problem. It was found that high contents of fines containing waterproofing agent and oilproofing agent was the main cause of this problem. Compared to the pulps without fines, pulp composed of 100% fines had lower absolute value of zeta-potential and higher adsorption ability of waterproofing agent and oilproofing agent. Besides, fines could increase the water retention capacity and prolong drainage time of pulp, which would result in higher drying intensity and generated strong vapor during drying. During hot pressing process of cellulosic pulp molded tableware production, the strong vapor could bring the small and light fines containing waterproofing agent and oilproofing agent into the air vents and the deposit was formed. The finding of this work would give supports for cleaner production of cellulosic pulp molded tableware by understanding the mechanisms of deposit formation which would be helpful to reduce the deposit problem to some extent.

Electiveness of agro-pulping process in the sustainable production of black liquor-based activated carbons.

During the production of paper pulp, the waste water loaded with organic materials from pulping process is discharged. Therefore, water treatment should be performed before disposing of such effluent. The use of such effluent for production of activated carbon will be effective in omitting the wastewater treatment and in obtaining the product required in many industries. In this respect, this paper deals with evaluating the performance of activated carbons (ACs) produced from black liquors (BLs) as by-products from three pulping processes of rice straw (RS) and sugar-cane bagasse (SCB), namely: alkaline, sulfite and neutral sulfite, which are coded SP, SSP and NSP, respectively. Elemental analysis and thermal analysis (TGA and DTGA) are carried out on the BLs, while the surface area (SBET), micro-/mesoporous distribution, adsorption capacity of methylene blue (MB) and iodine (I2-value), as well as Fourier transform infrared spectra (FT-IR) and scanning electron micrograph (SEM) are studied on synthesizing ACs. The optimal pulping approach for achieving BL-based AC, with the following characteristics: specific surface area (SBET) ∼ 921 and 545 m2 g−1, MB adsorption capacity 238 and 370 mg g−1, and I2-value 928 and 1255 mg g−1 of BL-based ACs, are from neutral sulfite pulping of SCB (B-NSP) and RS (RS-NSP), respectively. These finding data are ascribed to the carbon content of BL, as well as greatest total volume (VT 0.786 and 0.701 cm3 g−1) together with decreasing the volume of micropores/total (38 and 48%) of BL-NSP-ACs. It is interesting to note that the AC provided from RS-NSP has greater adsorption capacity for I2 and MB than the AC produced from RS-pulp fibres.

In vitro digestion and fermentation characteristics of tropical ingredients, co-products and by-products with potential use in diets for rabbits

The objective of this work was to evaluate and classify 16 tropical ingredients, co-products and by-products with potential use in rabbit feeding. We evaluated alfalfa hay, maize, wheat bran, soybean meal, crumbled maize with straw and cob (CMSC), soybean hull, citrus pulp, sugarcane bagasse, coffee husk, macauba seed cake meal (Acrocomia aculeata; MSCM), desmanthus hay (Desmanthus virgatus), sicklepod hay (Senna obtusifolia), neem hay (Azadirachta indica), Sodom apple hay (Calotropis procera), Barbados gooseberry hay (Pereskia aculeata) and moringa hay (Moringa oleifera). Chemically, were quantified dry matter (DM), crude protein (CP), ether extract (EE), neutral detergent fiber (aNDF), acid detergent fiber (ADF) and their nitrogen content (NDIN and ADIN, respectively), lignins, hemicelluloses, cellulose and non-fiber carbohydrates (NFC). Were evaluated the in vitro digestibility (ivDMdig) and degradability (ivDMdeg) of DM, and fermentation parameters, maximum amount of gas produced (B, mL/g DM), specific rate of gas production (C), decay of the specific rate of gas production (A), maximum fermentation rate (MFR, mL/h), time for maximum fermentation rate (TMFR, h) and latency time (LAG, h), using caecal inoculum for the in vitro evaluations. Were performed the hierarchical clustering on principal components (HCPC) of the data collected in the in vitro evaluations and obtained the matrix containing Pearson’s correlation coefficients between the chemical composition and the in vitro parameters. The values of DM, CP, Ash, EE, aNDF, ADF, lignins, hemicelluloses, cellulose, NDIN, ADIN, GE and NFC ranged from 857 to 906 g/kg, 22.9–552 g/kg DM, 7.0–153 g/kg, 5.26–136 g/kg DM, 204–697 g/kg DM, 20.6–493 g/kg DM, 2.27–226 g/kg DM, 73–443 g/kg DM, 18.3–437 g/kg DM, 25.3–395 g/kg CP, 19.9–227 g/kg CP, 13.3–21.7 MJ/kg and 38.9–690 g/kg, respectively. The results for ivDMdig, ivDMdeg, B, C, A, TMFR, MFR and LAG ranged from 0.21 to 0.84, 0.22 a 0.67, 79.9–348 mL/g DM, 2.75–4.44, 0.08 to 0.30, 8.58–38.8 h, 2.99–9.32 mL/h and 0.07–6.51 h, respectively. The results of the HCPC analysis determined the classification of the feeds into four groups: Group I contain sugarcane bagasse, coffee husk and citrus pulp; Group II contain soybean hull, desmanthus hay, MSCM, moringa hay and Barbados gooseberry hay; Group III contain alfalfa hay, Sodom apple hay, soybean meal, wheat bran, sicklepod hay and neem hay and Group IV contain maize and CMCS.

Enzymatic and cold alkaline pretreatments of sugarcane bagasse pulp to produce cellulose nanofibrils using a mechanical method

Lignocellulosic biomass is the most abundant renewable resource on the earth. With the development of related fields, the high value utilization of lignocellulosic biomass has gradually become a new avenue for research. In this study, unbleached bagasse pulp was pretreated with xylanase and cold alkali to partially remove hemicellulose and convert to some cellulose I into cellulose II. Cellulose nanofibrils (CNF) were then obtained through ultra-micro grinding and high-pressure homogenization. The prepared CNF were characterized by TEM, Zeta potential, ATR-FTIR and XRD, and a thermogravimetric analyzer was used to analyze the thermal stability of CNF. The results show that xylanase pretreatment can improve the dispersion of fibers during mechanical treatment and can enhance the crystallinity of CNF. With an increase in alkali concentrations, the proportion of cellulose II structures increased, while cellulose crystallinity levels decreased due to the folding of cellulose chains. Under the common influence of crystallinity and crystal structures, the thermal stability of the CNF prepared after cold alkali pretreatment underwent an increasing trend. This shows that the influence of crystal structures on the thermal stability of CNF gradually plays a dominant role as alkali concentrations increase.

Effects of D-hot pretreatment on micro-distribution of residual lignin in sugarcane bagasse pulp and fiber properties

Pretreatment of sugarcane bagasse pulp by hot chlorine dioxide has been performed to study delignification and structural changes in lignocelluloses. The compositions of the products were measured by gas chromatography mass spectrometry. The structure and morphology of the D-hot pretreated sugarcane bagasse pulps were characterized by FTIR, scanning electron microscope, X-ray diffraction, Metso Kajaani FS300 fiber analyzer and optical analyzer. Temperature played a crucial role in the lignin depolymerization and hemicellulose hydrolysis. The results show that the lignin content was reduced by 28.39% in the P layer and 20.93% in the S layer with increasing temperature from 60 to 95 °C. The resulting compositions of D-hot stage effluent were mainly including oxidized lignin and derivatives of furfural. Compared with the control, the category of oxidized lignin can be increased with D-hot pretreatment. Also, pretreated bagasse pulp has high brightness of 59.71% ISO, crystallinity index of 70.84%, L/W of 50.84 and outstanding optical properties. Therefore, bleached bagasse pulps might have the opportunities for further application in paper and paper-based materials. The graphical abstract showed that the changes of the crystallinity index (CrI), the brightness, and the L/W of the SCB pulp fibers with increasing reaction temperature from 60 to 95 °C. Also showed that the cross section of the single fiber and the region of P and S layer. EDS images of P and S layers for the unbleached SCB pulp, control pulp and D-hot bleached SCB pulps, the peaks corresponding to elemental carbon and oxygen were shown for the samples. In EDS, oxygen/carbon atom ratios and lignin mass in P and S layer of the unbleached pulp and bleached pulps were determined. The degradation products of lignin (1)–(3) in the control and degradation products (2)–(15) in the D-hot effluent were identified.

Effects of physical and chemical structures of bacterial cellulose on its enhancement to paper physical properties

Bacterial cellulose (BC) was used to reinforce paper sheets made from non-woody fibers, e.g. sugarcane bagasse. BC produced from static and agitated fermentation methods was mixed with bleached sugarcane bagasse pulp (BSBP) to produce composite paper sheets. BC from static culture had a higher degree of polymerization, crystallinity, and crystallite width. Adding BC at a low ratio (<1% of the dry weight of the sheets) can effectively improve the mechanical properties of BSBP paper sheets. Adding static BC improved the tensile index of BC-BSBP composite sheets up to 25%. Furthermore, BC was also chemically modified or cationized by reacting with (3-chloro-2-hydroxypropyl)trimethylammonium chloride. The results demonstrated that the cationization reaction had to be maintained at a low level (DS < 0.005) for effective improvement in mechanical properties of the BC-BSBP composite sheets. The improvements in tensile index were up to 10 and 32%, compared to the unmodified BC-reinforced sheets and sheets without BC, respectively. The low addition and low cationization levels suggest an economical prospect for static BC being used in the paper-based material industries to improve the qualities of non-woody fiber products.

Properties of thermomechanical pulps derived from sugarcane bagasse and oil palm empty fruit bunches

This research identified suitable conditions to fabricate pulp fibers for paperboards and medium density fiberboards (MDF) from the bagasse of sugarcane (Saccharum officinarum) and the empty fruit bunch (EFB) of oil palm (Elaeis guineensis). First, the effects of chemical pretreatments at 121°C and pressurized refining under steaming conditions were studied in regards to the thermomechanical pulps. The optimal conditions to achieve the highest paper strength properties of the EFB pulp involved pretreatment with 2% NaOH for 2h and refining at 0.7MPa of pressure at 165°C. The sugarcane bagasse (SB) pulp properties could not be improved by chemical pretreatment, while the EFB pulp properties clearly benefited from such pretreatment. Second, the effects of dry and wet blowing methods after pressurized refining on the fiber properties were examined. The strength properties of the half-dried SB and EFB pulps with 55% solid content were slightly higher than those of their wet counterparts. These results clearly suggest that SB and EFB can be promising refined fibers for paperboard and MDF preparation. Third, MDF was made from dried EFB refined fibers with 92% solid content by dry processing, and suitable properties for actual use were obtained.

Green synthesis of highly fluorescent carbon quantum dots from sugarcane bagasse pulp

Carbon quantum dots (CQDs) have great potential due to its advantageous characteristics of highly fluorescent nature and good stability. In this study, we aimed to develop a simple and efficient method for the green synthesis of fluorescent CQDs from sugarcane bagasse, a renewable and sustainable resource. The process involves the top down approach of chemical oxidation followed by exfoliation of sugarcane carbon. The synthesized CQDs was characterized by UV–vis absorption spectroscopy, Spectrofluorophotometry, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Raman spectroscopy, X-ray photon spectroscopy (XPS), Atomic force microscopy (AFM) and High-resolution transmission electron microscopy (HR-TEM). The synthesized CQDs possess stable fluorescent properties, good bio-compatibility and high quantum yield. The CQDs are highly crystalline with longitudinal dimensions of 4.1±0.17nm with an average roughness of around 5nm. The XRD and TEM analysis indicates that the synthesized CQDs possess face centred cubic crystal structure. The results suggest that the proposed CQDs could be utilized for bio-sensor, bio-imaging and drug delivery applications.

Promising bioethanol processes for developing a biorefinery in the Moroccan sugar industry

In order to establish a cost-effective biorefinery in Moroccan sugar plants, the use of sugarcane bagasse and beet pulp to produce bioethanol is considered as a promising option. In fact, lately this efficient way of biomass conversion into bioethanol, which is a cleaner source of energy, has received a lot of interest. In this context, the main objective of the present paper is to conduct a comparative study between the most investigated processes of producing bioethanol from lignocellulosic biomass. This study has considered the technical, economical, and environmental criteria to select the most efficient processes for a large scale production. For each step of the studied process, the most efficient options have been selected. In the pretreatment step, the use of dilute sulfuric acid was selected as the best option followed by steam explosion method. In the hydrolysis step, dilute sulfuric acid was also adopted. Concerning the following step, co-culture fermentation using a respiratory mutant of Saccharomyces cerevisiae and Pichia stipitis has been found to give the best result. In the last step, conventional distillation process coupled with pervaporation has been chosen as the best way to produce high purity anhydrous ethanol; while molecular sieves and extractive distillation in dividing-wall columns using ethylene glycol was also considered as promising alternatives of the pervaporation process.

Evaluation of the effects of chemical composition and refining treatments on the properties of nanofibrillated cellulose films from sugarcane bagasse

The different chemical and mechanical pre-treatments applied to pulp prior to nanofibrillation may also influence the characteristics of the fibrils and prepared films. In this work, the effects of the chemical composition and the degree of fibrillation of sugarcane bagasse pulps on the properties of the resulting nanofibrillated cellulose (NFC) films were investigated. Several environmentally-friendly treatments that reduce cost and simplify processing were applied to the bagasse fibres. Ethanol-based organosolv pulps with different residual lignin contents (2.9%, 5.0%, and 9.4%) were refined by Jokro milling and Bauer disk refining. Nanofibrils were isolated through an enzymatic treatment followed by high-intensity sonication. NFC films with similar morphologies were obtained with high crystallinity without changes in thermal stability relative to those of the initial materials. The residual lignin content affects the nanofibrillation process, the mechanical properties of the NFC filmsand modifies the film-water interactions. The combination of mechanical refining and enzymatic treatment was successful applied to produce homogeneous nanofibrils from sugarcane bagasse.

Production of cellulose nanocrystals from sugarcane bagasse fibers and pith

Cellulose nanocrystals (CNs) were produced from unbleached and bleached sugarcane bagasse pulps by classical H2SO4 hydrolysis of fiber and pith fractions of pressed culms. Both the raw materials and final products were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, field emission gun scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The advantages and disadvantages of using both unbleached and bleached pulps for the production of CNs were demonstrated and discussed.

이산화염소 표백단계와 킬레이트 처리단계 동시 진행 시 킬레이트 종류가 사탕수수 Soda-AQ 펄프 표백에 미치는 영향

Pulp made from sugarcane bagasse (SCB) was bleached in element chlorine free (ECF) sequence. The peroxide bleaching process for the final bleaching process has been introduced in order to reduce the use of chlorine dioxide. Prior to peroxide bleaching, different chelating chemicals were applied. When 4.5% of the total chlorine dioxide was used, bleached SCB pulp using additional DTPA chelate stage (DEDQP) resulted in 87.0% of the ISO brightness. However, bleached pulp using simultaneous stage of DTPA chelate and chlorine dioxide (DE(DQ)P) was reached at 83.9% of the ISO brightness. The viscosity of DEDQP bleached pulp was 25.6 cPs, and the one of DE(DQ)P bleached pulp was 21.9 cPs. Decreasing of chelate effect by chlorine dioxide led to a decrease in the final brightness and a lower viscosity. But simultaneous stage of EDTA chelate and chlorine dioxide (DE(DQ)P) led to higher final brightness (87.0% ISO) and higher viscosity (25.8 cPs) than those of the bleached pulp (86.4% ISO, 25.2 cPs).

Absorbable Organic Halide (AOX) Reduction in Elemental Chlorine-Free (ECF) Bleaching of Bagasse Pulp from the Addition of Sodium Sulphide

A laboratory investigation was developed to confirm and to quantify the reductions in absorbable organic halide (AOX) discharge when sodium sulphide was added during elemental chlorine-free (ECF) bleaching of sugarcane bagasse pulp. After the chlorine dioxide bleaching stage, the pulp was sent directly into the extraction stage without washing. FTIR was employed to determine the breakage of chemical bonds in the pulp, and GC-MS was used to measure the composition of the bleaching effluent. The addition of sodium sulphide caused a reduction in AOX of up to 46.7%. The AOX reduction reached this maximum when the sodium sulphide was added 30 min after the start of the extraction stage and when the pH was higher than 12. FTIR spectroscopy showed that the phenolic lignin of the pulp was degraded by the sodium sulphide and that the syringyl lignin and C-O-C, C=O structure of the pulp holocellulose of the pulp was preserved during the extraction stage. The GC-MS showed that the chlorobenzene and chlorophenol contents decreased noticeably after the addition of sodium sulphide.