Search or add a thesis

Advanced Search (Beta)
Home > Solid Phase Extraction of Heavy Metals Using Low Cost Sorbents

Solid Phase Extraction of Heavy Metals Using Low Cost Sorbents

Thesis Info

Access Option

External Link

Author

Wahid, Fazal

Program

PhD

Institute

University of Peshawar

City

Peshawar

Province

KPK

Country

Pakistan

Thesis Completing Year

2013

Thesis Completion Status

Completed

Subject

Chemistry

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/2609/1/2691S.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676727184755

Asian Research Index Whatsapp Chanel
Asian Research Index Whatsapp Chanel

Join our Whatsapp Channel to get regular updates.

Similar


The aim of present work is to investigate the sorption capacity of salvadora persica, activated carbon, chitosan and chemically modified chitosan for heavy metals from dilute solutions. Salvadora persica was converted into powdered form and characterized by using Infrared spectroscopy. It has various organic compounds and these compounds contain sulphur, oxygen and nitrogen in their skeletons and behave superbly as coordinating ligands for cations present in the aqueous solution and hence causing effective sorption. Activated carbon was also prepared from salvadora persica under vacuum at 673 K with different soacking time. The prepared activated carbons were characterized using Surface Area Analyzer. Percentage yield of the prepared activated carbons in different heating times prior to washing was different. The activated carbon yields obtained at 673 K were 54.78 %, 52.27 % and 50.31 % at 30, 45 and 60 min heating time, respectively. The yield of activated carbons decreased as the heating duration increased. Surface area decreased from 375 to 27 m2/g. 4-Acryloylmopholine was reacted with chitosan to alter it chemically .The aim of treatement was to enhance binding sites for heavy metals ions. The amended chitosan holds different binding sites (chelating centers) in the form of oxygen and nitrogen. Different techniques were applied to illustrate the amended chitosan. Activated carbons, powdered salvadora persica, chitosan and the chemically modified chitosan were used as sorbents for different cations (Cu 2+, Cd 2+, Pb 2+ and Ni 2+ ). Among these cations copper showed highest sorption ability as compared to other and the sorption properties were in agreement with that of the Langmuir model. The activated carbon prepared at 30 min heating time, showed maximum sorption capacities for cations due to its larger surface area. The Freundlich, Langmuir and Temkin models (both linear and non linear methods) were used to assess the experimental statistics. For activated carbon and powdered salvadora persica, lower errors were shown by type one (I) of the Langmuir model as compared to Freundlich and Temkin models, so it is the appropriate model to explain the sorption phenomenon. Among the linear forms of the Langmuir isotherms, low error values were given by type four (IV) than other linear forms of Langmuir and the Freundlich model but higher than that of Temkin model, which shows that Temkin model fits better to the experimental data of chemically modified chitosan.
Loading...
Loading...

Similar Books

Loading...

Similar Chapters

Loading...

Similar News

Loading...

Similar Articles

Loading...

Similar Article Headings

Loading...

1۔ حدِ زنا

1۔ حدِ زنا
زنا کا لغوی و اصطلاحی مفہوم
زنا کثیر المعنی لفظ ہے ۔ اس کا ایک معنی ہے، عظیم ، بلند، چنانچہ ابن فارس تحریر کرتے ہیں
"الزاء والنون والحرف المعتل لا تتضايف، ولا قياس فيها لواحدةٍ على أخرى. فالأوَّل الزِّنَى، معروف. ويقال إنّه يمدّ ويقصر. یقال أبا حاضِرٍ مَنْ يَزْنِ يُعرَف زنَاؤُهُ ۔ "71
"زنا کا اصل زا ء اور نون اور آخر میں ی معتل ہے اس میں کسی اور چیز کا اضافہ نہیں ہوسکتا اور اس میں ایک کو دوسرے پر قیاس نہیں کیا جا سکتا ۔ اس میں پہلا مادہ زَنَی َ ہے اور یہی معروف ہے اور یہ مدہ اور قصر دونوں کے ساتھ پڑھا جا سکتا ہے جیسے کہا جاتا ہے کہ وہ ایسا بلند مرتبہ شخص ہے جس کا عظیم مرتبت ہونا مشہور ہے۔ "
زنا حرام کا م ہے اور عظیم گناہوں میں ایک گناہ ہے ۔ ابن قدامہ نے زنا کو عظیم اور بڑا گناہ کہا ہے
"الزنا حرام وهو من الكبائر العظام ۔"72
زنا کا ایک معنی ہے گھر والے سے بغاوت کرنے والی عورت ،جیسا کہ ابن منظور لکھتےہیں
"الزِّنا يمد ويقصر زَنَى الرجلُ يَزْني زِنىً مقصور وزناءً ممدود وكذلك المرأَة وزانى مُزاناةً وزَنَّى كَزَنى... والمرأَة تُزانِي مُزاناةً وزِناء أَي تُباغِي۔ "73
"زنا مدہ اور قصر کے ساتھ پڑھا جا سکتا ہے" زَنَى الرجلُ يَزْني زِنىً" یہ مقصور ہے اور "وزناءً " یہ ممدود ہے اور اسی طرح عورت کے بارے میں ہے کہ زانیہ عورت یعنی اپنے گھر والے کے حق میں بغاوت کرنے والی ہے۔ "
بغیر نکاح کے کسی غیر عورت سے ہم بستری کرنا زنا کہلاتا ہے اور امام راغب اصفہانی کے بقول زنا
"الزنا وطءُ المراۃمن غیر عقد شرعی۔ "74
"عقد شرعی کے بغیر کسی عورت سے ہم بستری کرنا ہے۔ "
اصطلاحی مفہوم یہ ہے کہ...

عالمی امن میں اسلام کا کردار

We live in a global village. The cyber world has brought together people and shurnk the distences, yet multi cultural, multi ethinic and multi national has become the norm of the day. There is virtually no such place, no town, no village, city or state where people from diverse backgrounds speaking diffirent lagnuages and professing diffirent creeds live. This diveristy and variety is the essence of life.  This paper analyzes various ways of establishing peace in the light of Islamic teachings. It finds out the causes of quarrels and disputes in different nations so that they may be prevented to make the world peaceful.

Impact of Culture on Stock Market Returns and Volatility Spillover: Case of World Frontier Markets

As integration is related to systemic risk and rewards in the markets, it’s coupled with both weak and semi-strong form efficiency. Little or no evidence is found on return and volatility spillover of Frontier markets let alone the very new emerging area of cultural Finance. This study takes US and fifteen frontier markets out of 32 from all five regions defined by MSCI 2015, based on their data availability from January 2000 to December 2015 for sixteen years. This study uses the Diebold and Yilmaz''s (2009) measure of financial integration which uses decomposition of Variances in vector autoregressive models, on weekly data of returns and realized volatility to arrive at static and dynamic return and volatility indices. At the second layer of analysis the static indices are used in cross sectional country pair financial gravity model to know the determinants of return and volatility spillovers followed by Balli, Balli, Jean Louis, and Vo, (2015). With addition of Weighted mahalanobis, asymmetrical Cultural distance measure of Yeganeh (2014) by taking four dimension of culture from Hofstede (2001), in the cross sectional determinant model this study take next step by examining the relationships in independently pooled panel data paradigm. By taking bi-lateral returns and volatility spillovers with four sub-sample periods of 2000- 2003, 2004-2007, 2008-2011, 2012-2015 of four years each, the study incorporates dynamism in integration of not only interdependence in financial markets but also in cultural variables. Moreover, in both cross sectional and panel data setting this study investigates the channels through which Culture operates, motivated by the work of Lucey & Zhang (2010); Eun, Wang, and Xiao (2015); and Rothonis, Tran, and Wu, (2016) through introducing moderators in OLS models. Finally this study also includes the crisis index developed by Sachs, Tornell, and Velasco (1997) and used by Zhu and Yang (2008) to know the contagion of crisis in frontier markets and if Culture is a channel of contagion through simple OLS methodology in panel settings. The Markets are partially integrated and spillovers are low as compared to previous results of emerging and developed markets. The overall high volatility spillovers against returns give way to behavioral and cultural factors and non-existence of rational models of finance in decision making. US as representative of the developed markets shows highest contribution to the shocks in Frontier markets variance ratios in both cases. This study found high significant positive relationship to our cultural distance measure and support the notion that culturally distant countries have low levels of spillovers in both returns and volatility. Geographical proximity related hypothesis was completely rejected proving that frontier markets financial dynamics are not derived by regions. Trade openness is a channel through which relationship between culture and financial integration weakens in both spillovers, which leads to the theory of liberalization and efficiency as posited by Bekaert, Harvey, and Lundblad (2003). On the other hand Capital account openness enhances the culture-spillover relationship a little bit which is against the theory but we can attribute it to sociological concept of cultural lag, and as theorized by Lucey and Zhang (2010), it is proved that trading is also channel of cultural impact on both returns and volatility spillover. Interestingly from the five international scaled crises only Sovereign Debt crises created the relationship between national crisis index and Volatility/returns spillovers. According to results only return spillover spread through channel of culture not the volatility spillover. Theoretically it proves that both weak and Semi-Strong form of efficiency do not hold in frontier markets. Significant impact of cultural distances can be attributed to home biasness and information costs, moreover openness is gradual and time taking process.