Bioremediation of colored textile wastewater loaded with dyes and metals is a matter of great concern due to the hazardous risks associated with their untreated discharge into water bodies. The present study was conducted to isolate and characterize dye decolorizing metal tolerant bacterial strains for treatment of textile wastewater. For this purpose, 220 metal tolerant bacteria isolated from textile wastewaters coming from different textile industries in Faisalabad were tested for their potential to decolorize four different reactive dyes viz. reactive red 120 (RR120), reactive black 5 (RB5), reactive orange 16 (RO16) and reactive yellow 2 (RY2). Based on the potential to decolorize RR120, RB5, RO16 and RY2 in the presence of a mixture of four heavy metals (Cr, Cd, Zn, Pb), four bacterial strains viz. ZM17, ZM130, ZM160 and ZM183 were selected for subsequent studies. These strain were identified following the amplification, sequencing and bioinformatics analyses of their 16SrRNA, and were named as Raoultella sp. ZM17, Pseudomonas aeruginosa strain ZM130, Pseudomonas sp. ZM160 and Pseudomonas sp. ZM183. The selected bacterial strains were found to have varying levels of tolerance against the presence of different heavy metal ions in the media. Moreover, the decolorizing potential of these isolates was found to be decreased with an increase in the initial dye concentration. Furthermore, the interactive effects of four input variables including salt content, pH, C source concentration and level of multi-metal mixture on decolorization of RB5 by the selected bacterial strains were examined following response surface methodology (RSM) statistical modeling. All the four strains were also found capable of simultaneously removing Cr(VI) and all the reactive azo-dyes under study. However, the strain ZM130 was found to be the most efficient among these strains. The strains ZM17 and ZM183 were also found to harbor a dye decolorizing azoreductase Azr gene, whereas, a cadmium tolerant czcABC gene was found to be amplified from the DNA of the strains ZM130, ZM160 and ZM183. Enzymatic analyses of the strain ZM130 indicated that azo-reductase and tyrosinase activities were absent in this strain, however, this strain exhibited considerable activity of laccase and NADH-DCIP reductase activity during the decolorization of RR120. While testing the applicability of the strain ZM130 for treatment of synthetic wastewater, efficiency for color and COD removal of this strain was found to be favored and better in the anaerobic batch bioreactor as compared to aerobic batch bioreactor system. However, presence of yeast extract significantly increased the potential of ZM130 for color and COD removal with attached growth of microbial culture. The potential of the most efficient dye decolorizing metal tolerant bacterial strain Pseudomonas aeruginosa ZM130 for treatment of synthetic colored wastewater containing both RB5 (300 mg L-1) and hexavalent chromium (25 mg L-1) was also tested in vertical soil columns bio-augmented with this strain using sterilized and non-sterilized soil. It was interesting to note that the highest level of color, COD and Cr(VI) removal (˃90%) was achieved in the treatments where the soil columns were bio-augmented either with the sludge alone or the sludge along with ZM130 followed by the strain ZM130 along with addition of yeast extract. Based on the findings of the present study, it might be concluded that the selected bacterial strains, particularly Pseudomonas aeruginosa strain ZM130, harbor a varying but highly considerable potential for bioremediation of different xenobiotic compounds including dyes and heavy metals. Hence, this strain could be used to develop the bio-treatment systems (bioreactors) for addressing the problem of azo-dyes and metals in the wastewater.
ارضِ اقبال آفاقیت کے آئینے میں‘‘ڈاکٹر نصیر احمداسد کے مختلف تحقیقی و تنقیدی نوعیت کے مضامین پر مشتمل کتاب ہے۔بیشتر مضامین مختلف تحقیقی و تنقیدی رسائل کی زینت بن چکے ہیں۔ اُنھوں نے جن جن شخصیات پر قلم اٹھایا ہے،ان کے بارے میں معلومات کا ایک ذخیرہ جمع کر دیا ہے۔جہاں جہاں ضرورت محسوس کی ہے اپنی ناقدانہ رائے کا اظہار بھی بڑی خوب صورتی سے کیا ہے۔ مَیں نے ڈاکٹر نصیر احمد اسدکے مزاج میں ایک خاص بات محسوس کی ہے کہ وہ اپنے کام سے نہایت مخلص ہیں اور اپنی دُھن میں علمی خدمات میں ہمہ وقت مصروف نظر آتے ہیں۔ان کے اسلوب کی سادگی اور روانی بات کو بوجھل نہیں ہونے دیتی۔ ان مضامین کے مطالعہ سے قاری نہ صرف مختلف شخصیات سے متعارف ہوتا ہے بلکہ ان کی علمی خدمات سے بھی ایک حد تک مستفید ہوتا ہے۔ ’’مولوی فیروز الدین ڈسکوی‘‘ اور’’مولوی ابراہیم میر سیالکوٹی‘‘ والے مضامین میں مذکورہ شخصیات سے متعلق عمدہ معلومات جمع کی گئی ہیں۔ان شخصیات کے تعارف کے ساتھ ساتھ ان کی علمی خدمات پر بھی روشنی ڈالی گئی ہے۔اسی طرح ’’سیالکوٹ میں اردو شاعری کا ارتقا‘‘ اور’’ریاض حسین چودھری ایک نعت گو شاعر‘‘ میں ناقدانہ انداز نظر سے کام لیا گیا ہے۔دیگر مضامین بھی اپنی نوعیت کے خوب صورت مضامین ہیں۔الغرض مذکورہ کتاب ان کی تحقیقی و تنقیدی بصیرت کی آئینہ دار ہے۔ ڈاکٹر محمد افضل صفی صدر شعبہ اردو گورنمنٹ گریجوایٹ کالج ،کروڑ لعل عیسن، ضلع لیہ
This study revisited the literature to find answer to an important question that whether Zakat could or could not be paid to the non Muslims? There are different arguments in favor of giving the Zakat to the needy Dhimmies (non Muslims) in an Islamic State. After reviewing Islamic teachings, laid down in holy Quran and Sunnah, the practices of pious Caliphs, in the Islamic History, views of different Islamic schools of thought and the opinion of modern Islamic jurists, the study found that Quran and Sunnah allowed the payment of zakat to the Al-Muallaf-al-Qulub (poor non-Muslims and those, whose hearts are to be inclined). However, there are differences in the opinion of various Islamic schools of thought. For example, according to Maliki and Zaidi schools of jurisprudence it is lawful to give Zakat to the non-Muslims, where as Shyafee school of thought hold opposite opinion and does not allow the payment of Zakat to the non-Muslims. The modern Islamic jurists Muhammad Shaltut, Mustafa Al-Zarka, Taha Jabir, Syed Abual Aa la Maududi, Imam Khumany of Shia School of thought etc, argue that since modern states have become welfare states, it is therefore allowed to use zakat for the well-being of citizens including the non-Muslims. The recommendations given in this study are multidimensional that we will not only help the poor non-Muslims but also complement to eradicate poverty and reduce income inequality in Muslim countries
The main objective of the present research work was to explore the potentially unique properties and possible synergistic effect in supported bimetallic catalysts which were synthesized in two stages by adopting simple route. γ-Al2O3 granules were selected as a support material and prepared by sol gel process followed by oil drop method for granulation purpose. Co was chosen as low cost, basic metal and four noble metals (M): Ir, Ru. Pt, and Pd were selected as promoters. Four series of γ-Al2O3 supported bimetallic catalysts, (CoMx/γ-Al2O3) were synthesized via wet impregnation by loading ~ 20 wt% of Co metal and 0-5 wt% of promoter metals onto γ-Al2O3 in each series. On the basis of mole fraction (x) of promoter metals, the catalyst series were named as CoIrx/γ-Al2O3, CoRux/γ-Al2O3, CoPtx/γ-Al2O3, and CoPdx/γ-Al2O3. The prepared catalysts were characterized by various techniques i.e., Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) along with EDX analysis, transmission electron microscopy (TEM), surface area analysis, and temperature programmed reduction/oxidation (TPR/TPO) processes. In order to explore the diverse role, the synthesized catalysts were applied for hydrogen generation from two model reactions i.e., catalytic decomposition of hydrazine in a self-designed reactor and electro-oxidation of hydrazine by cyclic voltammetry (CV) technique. The catalytic decomposition of hydrazine (0.5 M) was performed at 25 oC and volume of gaseous products (H2+N2) was measured by a gravimetric water displacement method. The catalytic efficiency was evaluated in terms of turn over frequency (TOF) and selectivity (X) towards hydrogen generation. The optimal composition from each series was selected on the basis of activity and selectivity. Hydrazine decomposition reaction was further tested at various temperatures and activation energy (Ea) values were calculated from the kinetic profiles using Arrhenius equation. In particular, the kinetic studies depicted an increase in rate of hydrogen generation with an increase in temperature up to 65 oC. The effect of support was also studied by loading the selected optimal composition on various supports including MgO, ZnO, SiO2, and zeolite; (γ-Al2O3 proved to be the best iv support candidate). For electrochemical studies, glassy carbon electrode was modified with each catalyst powder by drop-casting and used for investigating electro-oxidation of hydrazine analyte in 0.1 M phosphate buffer solution (pH 7.2). Cyclic voltammetry was performed to elucidate the redox behavior of synthesized electroactive materials. A linear current-voltage response was observed on the modified electrodes in each catalyst series. The stability and reproducibility of all the catalytic materials was substantiated by the catalytic activity as measured in many successive cycles. All bimetallic catalysts showed potentiality for hydrogen generation and electrochemical applications. The combination of high TOF and selectivity for hydrogen generation as well as prominent current response in CV studies rendered CoIr0.081/γ-Al2O3, CoRu0.11/γ-Al2O3, CoPt0.034/γ-Al2O3, and CoPd0.093/γ-Al2O3 catalysts as optimal compositions in respective series. Out of these optimal compositions, CoPt0.034/γ-Al2O3 bimetallic catalyst exhibited maximum performance for hydrogen generation from hydrazine decomposition as well as for electro-oxidation of hydrazine. CoPt0.034/γ-Al2O3 catalyst presented 100% H2 selectivity with TOF of 190 h-1, and activation energy of 29 kJ mol-1. All bimetallic catalysts also showed robust electrocatalysis and presented good peak current response for electro-oxidation of hydrazine. These results reflected better alloying effect between Co and Pt metals in addition to presence of more active sites and better metal dispersion. The electroanalytical activity was in the order of: CoPt0.034/γ-Al2O3 > CoPd0.093/γ-Al2O3 > CoIr0.081/γ-Al2O3 > CoRu0.11/γ-Al2O3, with peak current values of 183.2 μA, 59.4 μA, 50.3 μA, and 46.1 μA, respectively. The maximum performance of the optimal catalysts can be attributed to tuning of catalyst’s properties by synergistic effect of two metals, better metal dispersion, metal-support interactions besides the excellent features of γ-Al2O3 granular support as confirmed by XRD, H2 chemisorption, BET, SEM, TEM, TPR and TPO analyses. In addition, noble metals in low contents promoted the activity and selectivity tremendously, and were quite suitable for making the process cost effective for selective decomposition of hydrazine, a toxic material into clean future energy fuel (H2 + N2).