scholarly journals Determining wash loss levels in the brownstock pulp washing line using different methods

TAPPI Journal ◽  
2017 ◽  
Vol 16 (05) ◽  
pp. 253-259
Author(s):  
Riku Kopra ◽  
Olli Dahl
Keyword(s):  
Lignin Content ◽  
Oxygen Demand ◽  
Pulp Mill ◽  
Measurement Methods ◽  
Chemical Recovery ◽  
Minimal Amount ◽  
Chemical Pulp ◽  
Washing Process ◽  
Chemical Pulping ◽  
And Control

The purpose of brownstock pulp washing is to recover the maximum amount of dissolved inorganic and organic material using a minimal amount of water. Brownstock washing is a notable subprocess in chemical pulping because it has effects on the subsequent treatments of the pulp and is also the first step in the chemical recovery cycle. Without effective washing, the economic viability of chemical pulp production is affected. The performance of washing can be described in two main ways: using wash loss, which describes the amount of washable compounds in the pulp suspension that could have been removed in washing; or the dilution factor, which represents the net amount of water that is added during washing. The amount of sodium in the pulp suspension after washing has typically been used as an indicator of wash loss, usually expressed as kg sodium sulfate/ovendry ton of washed pulp. Other common measurement methods are conductivity, chemical oxygen demand (COD), total organic carbon (TOC), dissolved dry solids (DDS), and lignin concentration. Scandinavian pulp mill softwood and hardwood fiber lines were investigated using various measurement methods in the pulp phases to gain better understanding of wash loss. The concentration of DDS in the streams was measured using a refractometer and laboratory scale. The pH, conductivity, lignin content, TOC, and COD were measured to look for any correlations. Using different methods, the level differences remain constant, but it is difficult to control the washing process with sufficient precision using individual measurements. The measurement methods must also be continuous and reliable to be used to monitor and control washing.

scholarly journals Extraction and characterization of nanofibrillated cellulose from yacon plant (Smallanthus sonchifolius) stem

2020 ◽  
Author(s):  
Romaildo Santos de Sousa ◽  
Alan Sulato de Andrade ◽  
Maria Lucia Masson
Keyword(s):  
Lignin Content ◽  
Crystallinity Index ◽  
Nanofibrillated Cellulose ◽  
Lower Amount ◽  
Infrared Analysis ◽  
Technical Feasibility ◽  
Smallanthus Sonchifolius ◽  
Chemical Pulp ◽  
Chemical Pulping

This study aimed to evaluate the process of cellulose extraction from yacon stem using combined pulping and bleaching processes for produce nanofibrillated cellulose (NFC). First, chemical pulping process with NaOH was applied and, subsequently, the pulp obtained was bleached. From the chemical pulp (CP) bleached, NFC was obtained by the mechanical defibrillation in a colloidal grinder. Then, chemical composition, color, and infrared analysis of the pulps was performed. The pulping process showed a lower amount of extractives and lignin content, as a low yield and an excessively dark pulp. The CP bleached with NaClO2 showed the best results increased whiteness of the pulp. A suspension of NFC with fibers of 5–60 nm in diameter, high crystallinity index, and thermal stability was obtained. The results are promising and demonstrate the technical feasibility of obtaining NFC from yacon stems waste which is ideal to apply to other materials of the industry.

Environmental benefits of magnesium hydroxide-based peroxide bleaching of mechanical pulp – mill results

TAPPI Journal ◽  
2013 ◽  
Vol 12 (6) ◽  
pp. 9-15 ◽  
Author(s):  
TOMI HIETANEN ◽  
JUHA TAMPER ◽  
KAJ BACKFOLK
Keyword(s):  
Sodium Hydroxide ◽  
Magnesium Hydroxide ◽  
Oxygen Demand ◽  
Pulp Mill ◽  
Transition Metal Ions ◽  
Environmental Benefits ◽  
Raw Material ◽  
Paper Machine ◽  
High Brightness ◽  
Peroxide Bleaching

The use of a new, technical, high-purity magnesium hydroxide-based peroxide bleaching additive was evaluated in full mill-scale trial runs on two target brightness levels. Trial runs were conducted at a Finnish paper mill using Norwegian spruce (Picea abies) as the raw material in a conventional pressurized groundwood process, which includes a high-consistency peroxide bleaching stage. On high brightness grades, the use of sodium-based additives cause high environmental load from the peroxide bleaching stage. One proposed solution to this is to replace all or part of the sodium hydroxide with a weaker alkali, such as magnesium hydroxide. The replacement of traditional bleaching additives was carried out stepwise, ranging from 0% to 100%. Sodium silicate was dosed in proportion to sodium hydroxide, but with a minimum dose of 0.5% by weight on dry pulp. The environmental effluent load from bleaching of both low and high brightness pulps was significantly reduced. We observed a 35% to 48% reduction in total organic carbon (TOC), 37% to 40% reduction in chemical oxygen demand (COD), and 34% to 60% reduction in biological oxygen demand (BOD7) in the bleaching effluent. At the same time, the target brightness was attained with all replacement ratios. No interference from transition metal ions in the process was observed. The paper quality and paper machine runnability remained good during the trial. These benefits, in addition to the possibility of increasing production capacity, encourage the implementation of the magnesium hydroxide-based bleaching concept.

scholarly journals Study of Ponds in Kathmandu Valley and Analysis of their Present Situation

2020 ◽  
Vol 12 (1) ◽  
pp. 38-54
Author(s):  
Bikash Adhikari ◽  
Anmol Parajuli ◽  
Prakash Adhikari
Keyword(s):  
Dissolved Oxygen ◽  
Sustainable Management ◽  
Field Survey ◽  
Oxygen Demand ◽  
Present Situation ◽  
Control Fish ◽  
Kathmandu Valley ◽  
E Coli ◽  
Dug Wells ◽  
And Control

Ponds in Kathmandu were constructed to feed the sub surface aquifers of stone spouts and dug wells at all seasons. The study focuses on how the ponds have been saved, reduced in size or completely lost. The causes behind the degradation of ponds are forces of intervention and disturbances that lead to the loss of the originality, quality and quantity of ponds throughout its timeline. Out of eight existing ponds in the study area, 10 samples were taken from eight different ponds for quality assessment. The historical significances and status, uses as of 2019 are tabulated based on field survey. The paper focuses on the study of pH, Total Solids, Electrical Conductivity, Ammonia, Nitrate, Phosphate, Ammonia, Dissolved Oxygen, Biological Oxygen Demand, Total Organic Matter, Chlorophyll, E. Coli, and dimensions of existing ponds. The physical, social stresses and lack of regular inspection of ponds have contributed to their degradation. However, the existing ponds require sustainable management. Proper safeguarding mechanism should be developed for the regular aeration of water in the ponds such as fountains so that the ponds have more dissolved oxygen eliminating faulty smell and control fish death.

The assessment of different operating strategies for minimising activated sludge deflocculation under temperature transient conditions

2004 ◽  
Vol 50 (3) ◽  
pp. 67-77 ◽  
Author(s):  
F. Morgan-Sagastume ◽  
D. Grant Allen
Keyword(s):  
Activated Sludge ◽  
Oxygen Demand ◽  
Pulp Mill ◽  
Temperature Shift ◽  
Batch Reactors ◽  
Substrate Removal ◽  
Removal Capacity ◽  
Floc Structure ◽  
Fundamental Research ◽  
Operating Strategies

Three operating strategies were tested for decreasing activated sludge deflocculation due to temperature shifts from 30° to 45°C: magnesium sludge enrichment, increased sludge retention time (33 d), and spikes of an easily degradable substrate (methanol). The temperature shifts were conducted sequentially in 4 parallel lab-scale sequencing batch reactors (SBRs) treating kraft pulp mill effluent. Three SBRs operated at an SRT = 20 days, and in one of them the sludge was not manipulated, thus, serving as a reference SBR. The temperature shift was associated with decreased soluble chemical oxygen demand (SCOD) removals, decreased sludge settleability and substrate removal capacity, and increased effluent suspended solids (ESS) and turbidity levels. The shift also increased the sludge specific respiration rates and reduced the sludge substrate removal capacity. Sludge deflocculation was assessed as floc solubilisation (increased effluent SCOD levels) and floc fragmentation (increase in effluent solids smaller than 50 mm). Mg enrichment of the sludge and methanol spikes reduced the ESS levels (in 9 and 25%), and the three operating strategies decreased effluent turbidity (in 22-35%) compared to the maximum levels from the non-manipulated reactor (44 mg ESS/L). The stronger sludge floc structure achieved by magnesium enrichment and a high sludge age of 33 days was unsuccessful in significantly decreasing deflocculation. The mechanisms involved in sludge deflocculation require further fundamental research.

The role of organic matter lost in kraft pulping material balances

2003 ◽  
Vol 47 (10) ◽  
pp. 61-69 ◽  
Author(s):  
A. Luonsi ◽  
S. Lento ◽  
S. Halttunen ◽  
K. Ala-Kaila
Keyword(s):  
Organic Matter ◽  
Oxygen Demand ◽  
Pulp Mill ◽  
Kraft Pulping ◽  
Efficiency Improvement ◽  
Unit Process ◽  
Volatile Solids ◽  
Volatile Organic ◽  
Washing Water

Efficiency improvement in a pulp mill includes minimisation of environmental discharges simultaneously with the development of pulp quality and production economy. Material balances in production processes, including fate of sidestreams, are key in proceeding these matters. Different approaches of determining the material balances increase understanding of process behaviour. We have focused on measuring sidestream (carryovers, washing water, filtrate) dissolved organic matter (DOM) in fibreline unit process blocks of softwood ECF bleached kraft production. The DOM was analysed by traditional wastewater methods (volatile solids, organic carbon, chemical oxygen demand). The measured data was combined with primarily simulated water balances and routine operational mill data in a simulation model. From this balance, yield estimate included, lost organic matter through complete degradation (CD) and volatile organic compounds (VOC) can be calculated throughout the fibreline. The sensitivity of this considerable amount (23-35 kgDVS/adt in total) to various factors is discussed in this paper.

GRAPHICAL REPRESENTATION OF CAUSE-EFFECT RELATIONSHIPS AMONG CHEMICAL PROCESS VARIABLES USING A NEURAL NETWORK APPROACH

2010 ◽  
Vol 09 (01) ◽  
pp. 69-86 ◽  
Author(s):  
GUSTAVO M. DE ALMEIDA ◽  
MARCELO CARDOSO ◽  
DANILO C. RENA ◽  
SONG W. PARK
Keyword(s):  
Visual Information ◽  
Graphical Representation ◽  
Pulp Mill ◽  
Process Variable ◽  
Chemical Recovery ◽  
Human Beings ◽  
Steam Generation ◽  
Fuel Temperature ◽  
Neural Network Approach ◽  
Operating Variables

The extraction of information from tabular data is not a natural task for human beings, which is worse when dealing with high dimensional systems. On the other hand, graphical representations make the understanding easier by exploring the human capacity of processing visual information. Such representations can be used for many purposes, e.g., complex systems structuring which contributes to a better understanding of it. This paper constructs a cause-effect map relating the influence of each input process variable on the steam generated by a boiler. The real case study is based on the operations of a chemical recovery boiler of a Kraft pulp mill in Brazil. The map is obtained by two steps, namely the identification of a neural predictive model for the steam and a study of sensitivity analysis. The numerical results are then depicted in a graphical format using a cause-effect map. This representation highlights the relative importance of the predictor variables to the steam generation. The results, in agreement with the literature, show the higher contribution of the heat released during the fuel burning, and the lower influence of both the fuel temperature and the operating variables associated with the primary level of injection of the combustion air.

Proteomic Analysis of Waldenstrom Macroglobulinemia (WM) Using Nanoscale Protein Micorarray Techniques.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 504-504
Author(s):  
Yazan Alsayed ◽  
Michael Timm ◽  
Alexey Leontovich ◽  
Daniel Santos ◽  
Allen Ho ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mtor Inhibitors ◽  
Pi3k Pathway ◽  
Protein Quantification ◽  
Minimal Amount ◽  
Newly Diagnosed ◽  
Apoptosis Protein ◽  
The Mean ◽  
And Control ◽  
Control Samples

Abstract The objective of this study was to determine the molecular alterations that occur at the protein level in patients with WM in order to identify novel targets of therapy, determine new markers of prognosis, and begin to delineate the pathogenesis of WM. Five bone marrow samples were obtained after informed consent from patients with symptomatic WM. Two bone marrow samples were obtained from age-matched controls and were pooled. All samples were purified with anti-CD19+ beads with over 90% purity. Protein quantification was performed and 1ug of protein was obtained for each sample and control. The nanoscale protein micorarray technique (BD Clontech, CA) was used to measure changes in the patterns of protein expression between WM samples and control lymphocytes. This is a new technique that detects differences in protein abundance between the tumor and control samples by hybridizing fluorescently labeled (Cy3 and Cy5) protein mixtures onto slides spotted with 512 monoclonal antibodies against human polypeptides. It requires minimal amount of protein. Two microarray slides were used for each experiment and a control experiment of control versus control was performed for normalization of the data. The slides were scanned using the Axon GenePix 4000B scanner. Two ratios were generated from the spot images for each protein target. The mean of the ratios of Cy5/Cy3 of both slides were analyzed using Clontech software and used to calculate an Internally Normalized Ratio (INR = ÷Ratio1/Ratio2, ratios 1 and 2 correspond to slides 1 and 2) for each spot on the array. The INR values were input into GeneSpring 6.0 software (Silicon Genetics, Redwood City CA). The data was normalized to the mean INR of the control samples. Proteins whose expression fold change relative to control was greater than 1.3 fold were determined. All samples were of symptomatic WM. There were 3 females and 2 males. The median age was 61 years (range, 47–83). Four patients were newly diagnosed and one had received prior rituximab, CHOP ad thalidomide therapy. Clustering analysis did not demonstrate a difference between newly diagnosed and treated samples. There were 72 proteins up or downregulated by 1.3 fold in all WM samples as compared to control. These included proteins in the PI3K pathway such as VHR, PTP1B, PI3K (p110alpha) and Rb2. Protein kinases such as PKCi, PKCbeta, PKC gamma, PKC delta, PLCgamma were all upregulated in WM samples. Other proteins included the B-cell specific activator protein PAX-5, the ubiquitin protein UBCH6, the STAT kinase STAT4, the GTPase Rho A-binding kinase ROK alpha, and the apoptosis protein SMAC/DIABLO. We demonstrate that several isoforms of the PKC family of proteins are upregulated in WM. PKC proteins regulate apoptosis, proliferation and migration in many cancer cells. These proteins may be useful targets of therapy in future clinical trials in WM. Other inhibitors that may be useful in WM include ubiqutin/proteosome inhibitors such as bortezomib and PI3K pathway inhibitors such AKT or mTOR inhibitors. Our results also confirm the presence of PAX-5 in WM consistent with previous cytogenetic studies. Supported in part by an ASH scholar award and Research Fund for Waldenstrom.

Reproductive Steroid Responses in Fish Exposed to Pulp Mill Condensates: An Investigation of Cause Case Study

2010 ◽  
Vol 45 (2) ◽  
pp. 163-173 ◽  
Author(s):  
Deborah L. MacLatchy ◽  
Craig Milestone ◽  
Kevin S. Shaughnessy ◽  
Andrew M. Belknap ◽  
Monique G. Dubé ◽  
...  
Keyword(s):  
High Performance ◽  
Fundulus Heteroclitus ◽  
Solid Phase ◽  
Pulp Mill ◽  
Chemical Recovery ◽  
Plasma Testosterone ◽  
Evaluation Approach ◽  
Identification Evaluation ◽  
Active Substances

Abstract An investigation of cause (IOC) approach integrating artificial stream exposures and laboratory bioassays has been used to identify waste stream sources of contaminants at the Irving Pulp & Paper Ltd. mill, in Saint John, New Brunswick, Canada. Chemical recovery condensates have shown the greatest potential for reducing circulating steroids in mummichog (Fundulus heteroclitus), an endemic fish species. A solid phase extraction (SPE) technique was developed to isolate hormonally active substances from the condensates, and a toxicity identification evaluation approach was used to gain a better understanding of the chemical characteristics of the active substances. Extracts were fractionated by high performance liquid chromatography (HPLC) and the fractions were used in a seven-day bioassay. Dose-response experiments indicated that steroid reductions in male mummichog were observed consistently after a 4% (vol/vol) exposure. At 4% (vol/vol), however, steroid reductions were not observed in fractions of the active SPE extract generated by HPLC. Some fractions actually induced increases in plasma testosterone. Recent work has focused on understanding what methodologies must be used to handle the semivolatile condensates to ensure 100% chemical recovery and retention of biological activity. Results are summarized in the context of developing an industry-wide IOC framework.

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