Search or add a thesis

Advanced Search (Beta)
Home > Organochlorine Residues in the Riverine Ecosystem of Pakistan

Organochlorine Residues in the Riverine Ecosystem of Pakistan

Thesis Info

Access Option

External Link

Author

Eqani, Syed-Ali-Musstjab-Akber-Shah,

Program

PhD

Institute

Quaid-I-Azam University

City

Islamabad

Province

Islamabad.

Country

Pakistan

Thesis Completing Year

2012

Thesis Completion Status

Completed

Subject

Natural Sciences

Language

English

Link

http://prr.hec.gov.pk/jspui/handle/123456789/1683

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676726829557

Asian Research Index Whatsapp Chanel
Asian Research Index Whatsapp Chanel

Join our Whatsapp Channel to get regular updates.

Similar


Present study aimed to provide the detailed data on Organochlorine Pesticides (OCPs) and Polychlorinated Biphenyls (PCBs) concentrations, possible sources, their seasonal variation, bioaccumulation and risk assessment. For this purpose; water, sediment and fish samples were collected from 25 site locations at River Chenab, during May 2007 to November 2009. Water samples were extracted by liquid-liquid extraction while sediment and fish samples were Soxhlet extracted, cleaned by column chromatography and finally analyzed by Gas Chromatography/Mass Selective Detector (GC-MSD). Concentration (ng/L) in surface waters (including particulate phase) of River Chenab ranged from 27-1100 and 25-1200 for OCPs and 7.7-110 and 13-99 for PCBs during summer and winter, respectively. Dichlorodiphenyltrichloroethane (DDTs) exhibited the highest concentration in all water samples following by Hexachlorocyclohexane (HCHs), Chlordanes, PCBs and other OCPs in descending order, respectively. DDT and PCB levels in surface water exceeded existing criteria concentration guidelines of USEPA. The concentrations (ng/g, dry weight) in sediment ranged from 29-831 and 11.4-811 for OCPs and 9.3- 129 and 12.5-144 for PCBs during summer and winter seasons. The risk evaluation highlighted the burden of γ-HCH, heptachlor, dieldrin and DDTs levels in 70% sediments, while PCBs concentration in 35% of sediment exceeded Effect Range Low (ERL) and Threshold Effect Level (TEL) values. Different indicative ratios for organochlorine residues in both water, and sediment suggested current use, long range transport along with past application of these chemicals. Statistical analysis highlighted agricultural and industrial activities and municipal waste disposal as main source of OCPs and PCBs in the riverine ecosystem of River Chenab. The level of OCPs and PCBs from feeding tributaries (i.e. S20) was relatively greater as compared to those collected from the River Chenab mainstream. The detection frequencies and concentrations of all OCPs and PCBs in water and sediment were higher in winter than those collected in summer season. OCPs and PCBs concentration (ng/g WW) ranged from 13-106 (mean; 38) and 3.1-93.7 (mean; 20) for five herbivorous fish species and 21.5-365 (mean; 148) and 2.4-108 (mean; 30) for six carnivorous species. DDTs, β-HCH, Page XVIII Chlordanes and PCBs detected in fish from distinct trophic levels highlighted biomagnifications. Risk assessments of OCPs and PCBs indicated that fish intake would pose a health risk to human. The findings of present study highlighted the contamination of OCPs and PCBs in River Chenab and there is an urgent need to mitigate the situation. The results can also be helpful for future management of other fresh water resources in the same region.
Loading...
Loading...

Similar Books

Loading...

Similar Chapters

Loading...

Similar News

Loading...

Similar Articles

Loading...

Similar Article Headings

Loading...

ڈاکٹر ہادی حسن

ڈاکٹر ہادی حسن
افسوس ہے پچھلے دنوں علی گڑھ میں ڈاکٹر ہادی حسن کابھی انتقال ہوگیا۔ مرحوم مسلم یونیورسٹی میں فارسی کے بڑے دیرینہ پروفیسر تھے،انگریزی اورفارسی دونوں زبانوں کے بڑے خوش بیان مقرر اورفارسی شعروادب کے نامور محقق تھے، حافظہ بلاکاتھا ،کسی کتاب کے صفحہ کے صفحہ بلا تکلف اپنی یاد سے پڑھ دیتے تھے۔ مسلم یونیورسٹی کے علاوہ ملک کی دوسری یونیورسٹیوں میں بھی ان کے علم وفضل اور تقریر وخطابت کی دھوم تھی۔ متعدد بلند پایہ کتابوں اورمقالات کے مصنف تھے۔ان کے فیضِ تعلیم وتربیت نے سینکڑوں نوجوانوں کو علم و فن کااستاذ اورماہر بنا دیا۔ بیوی کی وفات اور یونیورسٹی کی ملازمت سے سبکدوش ہونے کے بعد بالکل گوشہ نشین اورزندگی سے بیزار ہوگئے تھے،مگر مطالعہ اور تصنیف وتالیف کا شغل پھر بھی جاری تھا۔خوداُن کاذاتی کتب خانہ بڑی تعداد میں اہم اوربعض نادرالوجودکتابوں پر مشتمل ہے۔اﷲ تعالیٰ مغفرت ورحمت سے نوازے!
[جون۱۹۶۳ء]

 

بیوہ عورت کی کفالت سیرت طیبہ صلی اللہ علیہ وسلم کی روشنی میں

Holy Prophet (PBUH) has been made blessing for Humanity, and the being of Prophet (PBUH) is such an ocean of blessings that no any strata of society is derived of  by his teachings. Before the arrival of Holy Prophet (PBUH), the weak strata of society used to be oppressed in all its forms and manifestations, and suffered all sort of atrocity and cohesion. It is very core to the Teachings of Prophet (PBUH) that, it restored the rights of former oppressed class and brought its status equal to all. The list of oppressed and weak strata of society remained long, but our discussion is confined to the widow. Before Islam, the status of widow was very deplorable and she was ground under the oppression of all other strata of society. Even though in some religions, she was burnt alive with the corpse of husband. And somewhere her second marriage was denied and somewhere so on. But, a teaching of Islam and Holy Prophet (PBUH) has given a very crucial, respectable and safe as well as significant place to her in society. This article deals with this subject in detail, with solid references from different resources. In the end this articles carries suggestion for the welfare and development of widows.

Motion Correction in Compressively Sampled Dynamic Mr Imaging

Magnetic Resonance Imaging (MRI) is a non-invasive but slow imaging modality for studying different anatomical and functional aspects of human body. However, it is difficult for a patient to remain motionless during the slow MR acquisition process. The subject motion is one of the main hurdles in MRI due to the fact that the respiratory motion is faster compared to acquisition process resulting in ghosted and blurry recovered images. Cardiac and abdominal MR imaging is mostly affected by respiratory motion. In this thesis, compressive sensing (CS) based new approaches are developed to tackle the respiratory motion in cardiac and abdominal MRI examination. The cost function used by CS based MR recovery algorithms include ?1-norm penalty to exploit the transformed domain sparsity of the acquired MR data. The initial part of dissertation presents a comparison of surrogate functions used to approximate the l1-norm penalty. The experimental work shows that the hyperbolic tangent based function outperforms its competing function in the recovery of static MR images for different acceleration rates and various Gaussian noise levels. Based on these findings, an iterative thresholding algorithm utilizing hyperbolic tangent based ?1-norm approximation is developed to recover free breathing dynamic MR images from sub-sampled k-space data. A block matching algorithm, known as Adaptive Rood Pattern Search (ARPS) is then used to estimate and correct respiratory motion among the recovered images. In the next part, an adaptive thresholding parameter utilizing the MR data statistics is derived and used in wavelet domain shrinkage to recover both static and dynamic MR images. A novel iterative shrinkage thresholding (IST) algorithm based on the derived adaptive parameter is also proposed. Results show that the MR recovery using adaptive threshold is more effective in the presence of motion as compared to fixed threshold value. The final part presents the reduction of motion artifacts in the recovery of under-sampled abdominal and liver dynamic contrast enhanced (DCE) MR images using data binning and low-rank plus sparse (L+S) decomposition. In the data binning, radial k-space data is acquired continuously using golden-angle radial sampling pattern and grouped into various motion states or bins. The respiratory signal for binning is extracted directly from radially acquired k-space data. A compressed sensing (CS)-based L+S matrix decomposition model is then used to reconstruct good quality DCE MR images. The proposed techniques are validated using simulated and clinical MRI data.