Spatio-temporal change detection of land use and land cover in Malakand Division Khyber Pakhtunkhwa, Pakistan, using remote sensing and geographic information system.

The land use land cover (LULC) change due to the rapidly growing population is a common feature of the urban area. The rapidly growing population in Malakand Division is a greater threat to the LULC of the area due to its negative impact on environment and ecology. This research aims to detect the variations in LULC from 1991 to 2017 in the Malakand Division, Khyber Pakhtunkhwa (KP) province of Pakistan. The study relies on secondary dataset downloaded from the US Geological Survey (1991, 2001, 2011, and 2017 imageries) and the United Nations Office for the Coordination of Humanitarian Affairs (UN OCHA) website. Maximum likelihood technique under supervised image classification was opted to analyze the LULC changes in between 1991 and 2017. The results were based on six major land use classes including agriculture built-up area, vegetation cover, water bodies, snow cover, and barren land. The results from 1991 to 2017 show a substantial reduction in snow cover and barren land which is consequence of climate change. A known change has been recorded in built-up area which shows an increase from 1.02 to 6.2% with a change of 5.18% of the total land. The vegetation cover water bodies were also showing increase in area. The vegetation cover increased from 28.89 to 44.67% while barren land decreased from 45.68 to 40.29% of the total area. Furthermore, the built-up area increased from 1.02 to 6.2%, whereas water covers increased from 0.63% (1991) to 0.86% (2017) of the total area. The study concludes that there is an immense need for planning to preserve the natural habitat for sustainable development in the area.

Synthesis of Fe3O4@mZrO2-Re (Re = Y/La/Ce) by Using Uniform Design, Surface Response Methodology, and Orthogonal Design & Its Application for As3+ and As5+ Removal.

In this study, iron oxide (Fe3O4) was coated with ZrO2, and doped with three rare earth elements((Y/La/Ce), and a multi-staged rare earth doped zirconia adsorbent was prepared by using uniform design U14, Response Surface methodology, and orthogonal design, to remove As3+ and As5+ from the aqueous solution. Based on the results of TEM, EDS, XRD, FTIR, and N2-adsorption desorption test, the best molar ratio of Fe3O4:TMAOH:Zirconium butoxide:Y:La:Ce was selected as 1:12:11:1:0.02:0.08. The specific surface area and porosity was 263 m2/g, and 0.156 cm3/g, respectively. The isothermal curves and fitting equation parameters show that Langmuir model, and Redlich Peterson model fitted well. As per calculations of the Langmuir model, the highest adsorption capacities for As3+ and As5+ ions were recorded as 68.33 mg/g, 84.23 mg/g, respectively. The fitting curves and equations of the kinetic models favors the quasi second order kinetic model. Material regeneration was very effective, and even in the last cycle the regeneration capacities of both As3+ and As5+ were 75.15%, and 77.59%, respectively. Adsorption and regeneration results suggest that adsorbent has easy synthesis method, and reusable, so it can be used as a potential adsorbent for the removal of arsenic from aqueous solution.

Synthesis of magnetic core-shell amino adsorbent by using uniform design and response surface analysis (RSM) and its application for the removal of Cu2+, Zn2+, and Pb2.

The magnetic Fe3O4 was synthesized by using a one-step solvothermal method. Then, anhydrous ethanol as a solvent, tetramethyl ammonium hydroxide (TMAOH) as an auxiliary agent, tetraethyl orthosilicate (TEOS) as a silicon source, and (3-aminopropyl) triethoxysilane (APTES) as amino source were used to prepare Fe3O4@mSiO2-NH2 by using the sol-gel method. Uniform design U14*(145) and the response surface method (RSM) were used to optimize the synthesis ratio. According to the results of TEM, SEM, N2 adsorption-desorption test, VSM, and XRD, it found that the best coating effect obtained when the relative molar ratio of TMAOH:TEOS:APTES:Fe3O4 was 5:4:6:0.45. The results of EDS and elemental analysis confirmed the success of amino group coating; VSM magnetization after surface modification was 32 emu/g; BET results show that specific surface area is 236 m2/g, size 5 nm, and the pore volume is 0.126 cm3/g. The removal of Cu2+, Zn2+, and Pb2+ by Fe3O4@mSiO2-NH2 was studied at the optimal initial pH value 6 of the adsorption test system. The isothermal adsorption results show that the Langmuir model and Redlich-Peterson model are more suitable than the Freundlich model to describe the adsorption behavior, and Cu2+, Zn2+, and Pb2+ adsorption is mainly single molecular layer. The maximum adsorption capacity qm of the Langmuir model for Cu2+, Zn2+, and Pb2+ removal was 48.04 mg/g, 41.31 mg/g, and 62.17 mg/g, respectively. The adsorption kinetic rates of Cu2+, Zn2+, and Pb2+ on Fe3O4@mSiO2-NH2 relatively more suitable for pseudo-second-order kinetic model, i.e., R2, were ranged between 0.995 and 0.999, and the suitable reaction time was 60 min. These results proved that Fe3O4@m-SiO2-NH2 prepared by using this method is easy to synthesize, has easy recovery, is ecofriendly, and can be potential adsorbent for Cu2+, Zn2+, and Pb2+ removal.