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Home > Development of Chlorine Free Novel Bleaching Process for Wheat Straw Pulp to Reduce the Toxicity Level of Effluents

Development of Chlorine Free Novel Bleaching Process for Wheat Straw Pulp to Reduce the Toxicity Level of Effluents

Thesis Info

Access Option

External Link

Author

Yaqoob, Naila

Program

PhD

Institute

Lahore College for Women University

City

Lahore

Province

Punjab

Country

Pakistan

Thesis Completing Year

2011

Thesis Completion Status

Completed

Subject

Chemistry

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/2393/1/3009S.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676725870319

Similar


Wheat straw is a non-wood agricultural residue which serves as an excellent fibrous source for pulp and paper industry. In the present work, TCF bleaching sequences were developed for indigenous variety of AS/AQ wheat straw pulp. Different chemicals such as acid, oxygen, oxone, dithionite, alkali and hydrogen peroxide were optimized in different stages and sequences at varying doses of bleaching agents and reaction conditions. Multistage TCF bleach sequences i.e., AOOxPP*, AOOxEP, AOOxYP, AO′Ox′P′ are resulted from various optimization trials during the study. It was very promising to find out that cellulose remained protected whereas most of the residual lignin was removed during the process. Most of the hemicelluloses were washed away during bleaching. However, it is quite evident from the pulps’ sugar analysis that only a small fraction of hemicelluloses remained intact in the bleached pulp which is important in fiber preparation and its bonding during papermaking process. Similarly, hexenuronic acid was also removed during successive stages of bleaching that may be the causes of reduction in fiber strength, brightness and brightness stability. The results also revealed that the developed bleaching sequences are effective and selective to fully bleach the pulp with brightness gain greater than 80% ISO without deteriorating its fibre characteristics such as kappa number, viscosity, strength and brightness stability etc. A considerable reduction in effluent load with reduced toxicity and zero AOX level shows the advantage of process over chlorinated bleaching processes. Thus the study provides enough evidence to fill the gap between producing quality products and requirements for a healthy environment using TCF bleaching sequences.
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2۔ اہل اور تربیت یافتہ حکام کا انتخاب و تقرر

حکام بالا ،بااختیارمقتدر عہدیداران اور ملازمین و اہلکاروں کے بغیر نظام حکومت نہیں چل سکتا ۔ حکام میں صدر ، وزیراعظم ، گورنرز، وزرا ءسےمشیروں تک، قضاۃ سے لے کر فیصلہ لکھنے والوں تک اور مفتیان کرام تک سب شامل ہیں ۔ ان سب مناصب پر اہل ، ایماندار اور قابل لوگوں کا تقرر لازمی امر ہے ۔ ان حکام کے انتخاب کے لیے شریعت مطہرہ نے اصول و ضوابط مقرر فرمائے ہیں جو کہ مندرجہ ذیل ہیں:
2.1ریاستی عہدوں پر اہل افراد کا تقرر
سیاست کا ایک بنیادی اصول یہ ہے کہ ریاست میں انتظامی امورکی انجام دہی کے لیے تمام عہدوں اور مناصب پر اہل، باصلاحیت اور ایماندار افراد کا تقرر کیا جاناچاہئے ۔ حکومت کے اختیارات اور اموال اللہ اور اس کے رسول ﷺ کی امانت ہیں جنہیں خداترس، ایماندار اور عادل لوگوں کے سپردکیا جانا چاہئے اور اس امانت میں کسی شخص کواپنی مرضی کے مطابق ، یا نفسانی اغراض کے لئے استعمال کرنے کاحق نہیں ہے ۔ جب کسی منصب پرکسی نااہل شخص کا تقرر ہوتا ہے تومعاشرہ میں بدامنی، ظلم وزیادتی اور بے چینی کا آنا لازمی امر ہے، جیسا کہ حضرت ابو ہریرہؓ سے روایت ہے
"فَإِذَا ضُیِّعَتِ الأَمَانَۃُ فَانْتَظِرِ السَّاعَۃَ، قَال کَیْفَ إِضَاعَتُہَا؟قَال إِذَا وُسِّدَ الأَمْرُ إِلَی غَیْرِ أَھلِہِ فَانْتَظِرِ السَّاعَۃَ ۔" 345
’’ جب امانت ضائع کردی جائے تو پھر قیامت کا انتظار کرو۔ پوچھا کہ یا رسول اللہ امانت کیسے ضائع ہوگی۔ آپ ﷺنے جواب دیا کہ جب کوئی منصب کسی نا اہل کے سپرد کردیا جائے تو پھر قیامت کا انتظار کرو۔ ‘‘
اقربا پروری، تعلقات اورسفارش کی بنیاد پر جب عہدے تقسیم کیے جاتے ہیں تو اس کا نتیجہ یہ نکلتا ہے کہ نااہل اورناتجربہ کار لوگ عہدوں پر قابض ہو کر خلق خدا کو پریشان کرتے ہیں اور نظامِ حکومت برباد ہو...

Prevention Models of Occupational Contact Dermatitis in Beauty Salon Employees of Kendari City

This study aims to determine the effect of modifying factors, perceived vulnerability, perceived seriousness, perceived barriers and encouragement to prevent occupational contact dermatitis on beauty salon employees in Kendari City. This research is a quantitative study with a cross-sectional study approach using an explanative survey research design with a sample size of 100 respondents. The sampling technique used purposive random sampling. The data was collected by means of a questionnaire. Data analysis in this study used the SPSS program and Partial Least Squares (PLS). The results of this study indicate that there is a significant influence between modifying factors on perceptions of seriousness and barriers, on perceptions of vulnerability, there is a significant influence between perceptions of vulnerability, seriousness, barriers, encouragement on the prevention of occupational contact dermatitis.

Some New Results in the Theory of Fractional Second Grade and Ordinary Oldroyd-B Fluids

In this thesis some results regarding the flow behavior of second grade fluid with fractional derivatives and ordinary Oldroyd-B fluid under different circumstances have been studied. Firstly, some basic concepts regarding fluid motion and integral trans- forms have been discussed. Then the fluid motion of fractional second grade and ordinary Oldroyd-B fluids through a cylinder and annulus is studied. In chapter 2, the motion of fractional second grade fluid through an infinite cir- cular cylinder has been studied. After time t = 0+ the fluid motion is produced by rotating the circular cylinder about its axis. Laplace and finite Hankel transforms are used to find exact solutions. The similar solutions for Newtonian and ordinary second grade fluids are obtained as limiting cases of general solutions by making κ → 1 and α1 → 0, respectively κ → 1 . Chapter 3 intends to establish exact solutions for the unsteady flow of a fractional second grade fluid between two infinite coaxial circular cylinders. The general expres- sions for velocity and shear stress are obtained by using Laplace and finite Hankel transforms. The motion of the fluid is produced by the inner cylinder which is ro- tating around its axis due to a time-dependent torque per unit length 2πR1 at2 . The solutions that have been obtained satisfy all imposed initial and boundary conditions. For κ → 1, respectively κ → 1 and α1 → 0, the corresponding solutions for ordinary second grade and Newtonian fluids, performing the same motion, are obtained as limiting cases. In chapter 4 the unsteady helical flow of an Oldroyd-B fluid through an infinite circular cylinder is studied. The motion of the fluid is produced by cylinder that, after time t = 0+ , is subject to both torsional and longitudinal time dependent shear stresses. The general solutions are presented in series form in terms of Bessel functions J0 (•), J1 (•) and J2 (•), and satisfy all imposed initial and boundary conditions. The corresponding solutions for Newtonian, second grade and Maxwell fluids are obtained as limiting cases of general solutions. Finally, the obtained solutions are compared by graphical illustrations and the influence of material parameters on the fluid motion is also underlined. Chapter 5 concerns with the unsteady Taylor-Couette flow of an Oldroyd-B fluid in an annulus due to a time-dependent torque applied to the inner cylinder. Motion is studied by means of finite Hankel transforms. The exact solutions are presented in series form in terms of usual Bessel functions, satisfy both the governing equations, and all imposed initial and boundary conditions. Similar solutions for Newtonian, second grade and Maxwell fluids performing the same motion are obtained as limit- ing cases of general solution. Finally, some characteristics of the fluid motion, as well as the influence of pertinent parameters on the behavior of the fluid motion, analyzed by graphs.