Chlorinated organic compounds are released to the environment as a result of production, use and inefficient handling of these compounds. Such compounds are highly stable, toxic toward living organisms including humans and causes cancer and other disorders. Trichloroethylene (TCE), a representative of chlorinated organic compounds is largely used in various industries and its release impacts adversely on environment. To control its damaging effects, removal and decomposition of TCE is highly desirable. The current study is focused on synthesis of novel Iron loaded spherical mesoporous silica particles (SMSPs) and its application as adsorbent for dechlorination of TCE. The silica was synthesized using modified Stöber’s method at varying temperatures (20-70 °C) to study its effect on the size and porosity of the synthesized particles. Loading of iron into silica follows two routes to carry out pre and post modification of mesoporous silica particles through sol gel and reduction process. During the synthesis, ratio of silica to Iron is varied from 1:10 to 1:5 to study its impact on loaded iron and porosity of the Iron loaded spherical mesoporous silica particles (Fe-SMSPs). The synthesized particles were characterized using a range of techniques including fourier transformed Infrared spectroscopy (FTIR), raman spectroscopy, Energy dispersive X-ray spectroscopy (EDX), dcanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and BET surface area measurement. The results show that synthesized SMSPs have mean diameter of 627±140 nm at room temperature and decreases to 408±156 nm at 60 °C. SMSPs also exhibited high BET surface area (627 m2/g) that determines its high efficiency for uptake of iron into the mesoporous structure. However, loss of spherical structure is also witnessed on increasing silica to iron ratio (1:3) during synthesis. Series of batch experiments were carried out to test dechlorination efficiency of the synthesized Fe-SMSPs against TCE. HPLC data indicated rapid decrease and removal of 25 ppm TCE in two hours at room temperature. Mass spectrometry revealed formation of hydrocarbons as dechlorination products. The present research concludes that the synthesized Fe-SMSPs have a promising potential to be used for dechlorination of TCE contaminated water. This has special preference for underground water treatment. Future prospects determine applicability of these materials for dechlorination of other chlorinated organic compounds than TCE.
1977 ء میں شائع ہونے والی پروفیسر عبدالحق کی اس کتاب نے بہت شہرت حاصل کی۔ اس میں آپ نے شیخ ظہور الدین حاتم کے کلام کی تدوین کی ہے اور حاتم کو شمالی ہند کا سب سے پہلا شاعر تسلیم کیا ہے۔ یہ کتاب دیوان حاتم کے نام سے 2008ء میں اور پھر 2010ء میں اور پھر 2011ء میں شائع ہوئی۔ جس نے ثابت کر دیا ہے کہ حاتم ہی شمالی ہند کااولین شاعر ہے۔ پروفیسر تو قیر احمد خاں اس پر تبصرہ کرتے ہوئے فرماتے ہیں: پروفیسر عبد الحق نے اس سلسلہ میں بڑی گراں قدر تحقیق کی ہے اور مختلف شواہد سے ثابت کر دیا کہ حاتم ہی شمالی ہند کا پہلا صاحب دیوان شاعر ہے ۔ (31)
Islamic Fiqh is the representative of legal aspect of Islam. It has been originated and established on direct teachings of Qur’an and Sunnah of the Holy Prophet Muhammad (SAW). These two sources are called primary sources of Islamic law. There are some supplementary sources to the primary sources; Istihsan (Juristic Preference) is one of these. Orinetalist’s studied and produced literature on Islamic law. Istihsan has also been discussed by them but they have different opinions about its origin and its role in Islamic law. In this article their opinions are being critically analyzed and the definition, role and types of Istihsan being presented according to Muslim’s viewpoint. This research concluded that the Goldziher, Joseph Schacht, MicDonald, David Pearl, and Benjamin Jokisch explanations about the establishment of Isti╒san are not correct.
High ethylene concentration under different environmental stresses such as salinity is one of the contributing factors for premature senescence of different plant parts. Plants under salinity stress produce increased levels of ethylene which inhibit the plant growth. Microbial 1-aminocyclopropane-1-carboxylic acid (ACC)-deaminase is the enzyme which is present in some strains of plant growth promoting rhizobacteria (PGPR). These PGPR alone and also in combination with rhizobial strains promote plant growth by lowering the endogenous level of ethylene along with some other mechanisms. A number of rhizobacterial and Rhizobium strains were isolated from rhizosphere and nodules of mung bean, respectively. The rhizobacterial strains were screened on the basis of ACC metabolism assay. The selected rhizobacterial strains containing ACC-deaminase activity and Rhizobium were assessed for their ability to tolerate salt stress by conducting osmoadaptation assay. These strains were further screened for their ability to promote growth of mung bean seedlings under salt-stressed axenic conditions in growth pouch/jar trials. Three most effective strains of PGPR (Mk1, Pseudomonas syrigae; Mk20, Pseudomonas fluorescens and Mk25, Pseudomonas fluorescens Biotype G), and Rhizobium phaseoli (M1, M6 and M9) were screened in co-inoculation for their growth promoting activity at original, 4 and 6 dS m-1 under axenic conditions. Strains from three most effective combinations were tested alone and in combinations in pot and field trials for their potential to improve growth, nodulation and yield of mung bean under salt- affected conditions. Results showed that salinity stress significantly reduced plant growth, some physiological parameters, nodulation and yield but inoculation with PGPR containing ACC-deaminase and rhizobia improved these, thus reducing the inhibitory effect of salinity. However, their combined application was more effective under salinity and the co-inoculation with PGPR strain Pseudomonas fluorescens and Rhizobium phaseoli was the most efficient for improving growth, nodulation, physiology and yield of mung bean. The effect of high ethylene concentrations on plant growth and performance of these strains for reducing this negative impact was also evaluated by conducting classical triple-response bioassay. Intensity of the classical triple response decreased due to inoculation with these strains as the root/shoot length of inoculated mung bean seedlings increased while stem diameter decreased which is typical indication of the dilution in classical triple response. Such bacteria could be very effective as co- inoculants to improve growth, physiology, nodulation and yield of mung bean under salt affected conditions. However, the degree to which these inoculants impart benefits to plant growth can vary with the conditions and PGPR strains. A PGPR strain with multiple traits could be more useful under diverse conditions compared to a strain containing single trait.