This dissertation study aims to the investigation of new biosorbent from locally available low cost agriculture material, rice husk, for scavenging of heavy metals especially precious and rare earth metals. Rice husk was treated with NaOH solution to check the effect of modification on metal ions adsorption. Rice husks treated and virgin were characterized by Fourier transform infrared (FT-IR) spectrometry, Scanning Electron Microscopy (SEM), Energy dispersive X- Ray (EDX) and Brunner EmmetTeller (BET) techniques. The rice husk (RH) & NaOH treated rice husk (TRH) were characterized by various physico-chemical methods like porosity, bulk density, ash, volatile and moisture contents, pHPZC, pH and methylene blue surface area measurements. The determined surface area of RH was 47.91 and TRH was 272.06 m2 g−1 by methylene blue method whereas BET surface area was 1.03 for RH and 2.53 m2g−1 for TRH. From the comparison of FTIR spectra of RH and TRH and metals loaded adsorbent, it was found that metals ions mostly attached with the oxygen and silicon containing functional groupsThus OH, −COOH, O CH3 and Si−O−Si, functional groups play vital role in the adsorptive removal of heavy metals ions from aqueous solutions. SEM analysis showed that RH and TRH possess rough and porous structures and the morphological difference between them revealed that the NaOH treatment created large and wide pores making TRH more rough and porous material. The pore size for untreated rice husk was 100-108 nm and for treated rice husk was 355.57 to 1220 nm confirming macro porous structure of the adsorbent. SEM exhibited the morphological changes on the adsorbent surface after metal ions adsorption and were confirmed by EDX analysis by the presences of these metal ions on the adsorbent surface. Various physico-chemical parameters such as pH, mineral acid concentrations (HNO3, HCl, H2SO4 and HClO4), amount of adsorbent, contact time, initial metal ions concentration and temperature have been optimized for maximum removal of metal ions from aqueous media by rice husk employing batch mode. The removal of metal ions were quantitative within a short contact time of 10 - 25 minutes for all metal ions (Ag, Cs, Cu, Co, Ni, Th, La and Ce). Maximum adsorption of silver and cerium was observed in 1 × 10-2 mol L-1 of nitric acid solution whereas maximum adsorption in case of thorium, nickel, lanthanum and caesium was found in 1 × 10-2 mol L-1 nitric acid solution. The adsorption data obtained by the variation of equilibrium time was applied to various kinetic models. Pseudo second order was the best fitted kinetic model for the adsorption of precious and rare earth metal ions. Mechanism of metal ions uptake was verified by applying intra-particle, liquid film and Elovich models. The adsorption data of metal ions on rice husk obeyed the Freundlich, Langmuir and Dubinin-Radushkevich isotherm equations. Adsorption capacities of rice husk for all these metal ions were calculated form their linear and nonlinear forms. Regression coefficient ‗R2‘ and Chi square test ‗χ2‘ were used as the criteria for the best fit of adsorption isotherm models. The adsorption capacities of the rice husk obtained by the Freundlich isotherm were compared with the reported adsorption capacities of various adsorbents and rice husk was found better adsorbent for the removal of these metal ions from aqueous media. The sorption free energies determined by D-R isotherm confirmed chemisorption type of adsorption of metal ions on rice husk having numerical values in a range of 10.16 – 22.43 kJ mol−1 for the metal ions in this study. The adsorption processes were found to be endothermic in nature with positive values of ∆H in a range of 3 839 – 31.016 kJ mol−1 and ∆S values (16 839 – 115.764 J mol−1 K−1) confirmed increase in randomness at the solid-solution interface by the fixation of metal ions on the rice husk. The increased numerical values of ∆G with rise in temperature indicates that the adsorption process of metal ions ( Cu, Co, Ag, Ni, Cs, Th, La and Ce) on rice husk becomes more favourable at higher temperatures. Sticking probabilities and activation energies of all metal ions system favour the chemisorption nature of interactions with rice husk. The adsorption of metal ions occurs in the presence of a variety of anions and cations. Regeneration of adsorbent and recovery of metal ions were performed by using different concentrations of nitric acid. The developed procedures were successfully applied to the spiked tap water samples by removing the metal ions under optimized conditions. The maximum metal ions removal was obtained in two steps under optimized conditions. On the basis of this study it was concluded that abundantly and locally available inexpensive rice husk has great potential to be utilized for the removal of precious and rare earth metal ions from bulk aqueous solutions for the safe disposal of industrial as well as radioactive effluents and will provide an alternative solution to minimize environmental damages caused by these metal ions.
Life of Iqbal is the source of many virtues. This article focuses on some of the sources and motivations that influenced Iqbal's personality. Home environment was the first school of training for Iqbal. Parent's training made him a person of outstanding qualities from the time of childhood. The teachers polished more. Iqbal was also influenced by Sir Syed's movement. This article will give you a glimpse of the research and critique of many new aspects. We must consider the motives of Iqbal's knowledge and wisdom. By the study of these motives, we can examine the mental evolution of Iqbal. Therefore, everything should come to light. Iqbal also expressed his love for nature but within limits. Otherwise, people would make nature an idol and start worshiping it. Authoritative quotes from experts are the part of this research article. These references will provide assistance in the topics of Iqbal Studies.
The purpose of this study was to improve the job performance of teachers by measuring the factors affecting the performance of teachers at higher secondary level. Main objectives of the study were to measure and summarize the perceptions of principals, teachers themselves and students about the factors that influence teachers’ performance, to compare teachers’ performance on each factor in the light of perceptions of principals, teachers themselves and students, to determine the rating of principals, teachers themselves and their students on each factor, to discover the level of presence of each factor on teachers’ job performance in the light of perceptions of principals, teachers themselves and students and to recommend improvement of the existing situation. The study was descriptive in nature. All the principals, teachers and students at higher secondary level in Punjab constituted the population of the study. The principal, five teachers and ten students were included in the sample from each institution, thus the sample consisted of 1920 individuals i.e. 120 principals, 600 teachers and 1200 students. Three types of closed ended questionnaires on five point rating scale were prepared separately for principals, teachers and students. The data obtained were tabulated, analyzed and interpreted by using statistical techniques as, mean, standard deviation, average rating and analysis of variance (ANOVA). The main conclusions of the study were that the factor of subject mastery was perceived by the principals, teachers themselves and students to be at the highest level among the four factors of teachers’ job performance. The factor of attitude toward students was viewed to be at the lowest level among the four factors of teachers’ job performance. Teaching methodology and teachers’ personal characteristics were factors considered to be present in teachers’ performance at intermediary level. xiiiThe average rating of teachers was the highest whereas that of students was the lowest on all the four factors, namely the attitude toward students, subject mastery, teaching methodology and personal characteristics of teachers’ job performance. The rating of the principals was at intermediary level. There was no real difference among the views of principals, teachers themselves and students about teachers’ performance on the factors of attitude toward students, subject mastery and teaching methodology. However, the views of principals, teachers themselves and students were found different on the factor of teachers’ personal characteristics. On the basis of analysis of the study, it was recommended that though the factor of teachers’ job performance was found on the highest level in the present study, yet teachers should continue their attention and improve their command on the content through self study and by attending in service refresher courses. The attitude toward students, as a factor of teachers’ job performance as analyzed was perceived at the lowest. So teachers need to improve their approach toward the students in order to improve their performance. Teachers are required to continually improve their teaching methodology by consulting internet media, new informatory literature to bring innovation in their teaching methodology. The factor of personal characteristics of teachers’ job performance was given the third position among the four factors, thus teachers should give specific attention toward this factor by improving their personality characteristics such as use of easily understandable language, removal of potential blocks to communication, use of key vocabulary, use of different channels of communication to facilitate the students and xivalso speak clearly and vary the tone pitch and inflection of the voice to all areas of the classroom. In the light of above mentioned conclusions, it can be suggested that if teachers improve their performance on the four factors attitude toward students, subject mastery, teaching methodology and personal characteristics, a significant improvement can be made in teachers’ job performance. Due to few research studies conducted in Pakistan, there is a need to conduct more studies in this area in the future. The present study was conducted in the province of Punjab, the future researchers may expand it to other provinces of the country in order to measure the factors affecting the teachers’ job performance at national level. The present study was delimited to four factors only as attitude toward students, subject mastery, teaching methodology and personal characteristics, whereas the literature indicates a number of other factors such as the classroom environment, general mental ability, personality, relations with students, preparation and planning, effectiveness in presenting subject matters, relations with other staff, self improvement, relations with parents and community, poise, intellect, teaching techniques, interaction with students, motivational skills and fairness in grading etc.