Development of Novel PET-PAN Electrospun Nanocomposite Membrane Embedded with Layered Double Hydroxides Hybrid for Efficient Wastewater Treatment.

Layered double hydroxides (LDHs) with their unique structural chemistry create opportunities to be modified with polymers, making different nanocomposites. In the current research, a novel PET-PAN embedded with Mg-AI-LDH-PVA nanocomposite membrane was fabricated through electrospinning. SEM, EDX, FTIR, XRD, and AFM were carried out to investigate the structure and morphology of the nanocomposite membrane. The characterization of the optimized nanocomposite membrane showed a beadless, smooth structure with a nanofiber diameter of 695 nm. The water contact angle and tensile strength were 16° and 1.4 Mpa, respectively, showing an increase in the hydrophilicity and stability of the nanocomposite membrane by the addition of Mg-Al-LDH-PVA. To evaluate the adsorption performance of the nanocomposite membrane, operating parameters were achieved for Cr(VI) and methyl orange at pH 2.0 and pH 4.0, respectively, including contact time, adsorbate dose, and pollutant concentration. The adsorption data of the nanocomposite membrane showed the removal of 68% and 80% for Cr(VI) and methyl orange, respectively. The process of adsorption followed a Langmuir isotherm model that fit well and pseudo-2nd order kinetics with R2 values of 0.97 and 0.99, respectively. The recycling results showed the membrane's stability for up to five cycles. The developed membrane can be used for efficient removal of pollutants from wastewater.

A figure of merits-based performance comparison of various advanced functional nanomaterials for adsorptive removal of gaseous ammonia.

The implementation of sustainable industrial development based on energy/cost-effective techniques with zero/low rate of pollutant emission is an ideal strategy for the proper management of a natural environment. Gaseous ammonia released from a variety of anthropogenic sources (e.g., agriculture, pharmaceuticals, commercial cleaning products, and refrigerant) is estimated to be as high as 150 million tons∙year-1. To reduce the negative effects of atmospheric ammonia, the great utility of advanced functional nanomaterials (e.g., metal organic frameworks, covalent organic polymers, metal/metal oxide nanoparticles, and carbon nanostructures) has been recognized. To gain a better understanding of the sorptive removal potential of diverse materials, their performance has been evaluated based on the key performance merits (e.g., initial concentration, sorption capacity, and partition coefficient). Generally, the PC values can be applied to significantly estimate the contaminant adsorption potential of NMs via balancing the biased influences of operating parameters (e.g., initial concentration of pollutants) as perceived for the partitioning of compounds between aqueous phases at equilibrium (e.g., Henry's Law). Therefore, in this work, we have proposed the PC as a prosperous performance merit (in terms of heterogeneity of surface and strength of adsorption process) for the selection of high performance nano-adsorbents for gaseous ammonia. Moreover, the water stability, recyclability, economic aspects, and future perspectives have also been discussed for real-world applications of advanced nanomaterial against gaseous ammonia adsorption. The outcome of this evaluation will be expedient for the classification/selection of the most effectual and cost-effective options for mitigation of environmental pollutants like gaseous ammonia.

Modeling and simulation of solar flat plate collector for energy recovery at varying regional coordinates.

Pakistan has remained an energy-deficient country, and most of the industrial sectors are closed due to the loading shedding of electricity. Even though Pakistan is located on the "solar belt" and receives over 2 MWh/m2 solar irradiation per year with 1500-3000 h of sunshine, unfortunately solar energy is not harnessed to fulfill the energy needs of the country. Solar flat plate collectors (SFPC) are widely employed for collecting solar radiations from the sun. Currently, worldwide solar thermal energy is widely used in household and commercial equipment for energy collection and utilization. The working fluid selected for this research work is water; numerical simulations were performed using Ansys FLUENT. On selected geographical coordinates, solar ray tracing model was employed to incorporate solar heat flux. Nawabshah (NWB), Hyderabad (HYB), Jacobabad (JCB), and Mirpurkhas (MPK) cities were selected for the measuring of performance of SPFC. Firstly, parallel to ground (at a 0° tilt angle) orientation of SFPC was performed. Furthermore, the performance of SFPC was measured using tilt angles of 15°, 30°, and 45°, respectively. The maximum exit water temperature in JCB at a tilt angle of 30° was 97.8 °C in March and a minimum of 88.09 °C in June. In HYD, at a tilt angle of 45°, the maximum temperature rise was recorded at 98.01 °C in November and the minimum was noticed at 76.37 °C in June. While in JCA, at an angle of 30°, the highest temperature was recorded at 97.83 °C in February and a minimum of 78.54 °C in June. The specific aim of this research study was to measure the performance of the SFPC at different tilt angles and at varying geographical coordinates through numerical simulations.

Experimental investigations of arsenic adsorption from contaminated water using chemically activated hematite (Fe2O3) iron ore.

Indigenous hematite iron ore was chemically activated as a function of various hydrogen peroxide concentrations (0.5, 1, 1.5, and 2.0 M), activation time, and iron ore size. Adsorption potential was evaluated at various initial arsenic concentrations, contact time, adsorbent dose, and particle size. Maximum 95% removal efficiency was achieved at 600-µm size of iron ore, activated with 0.5 M concentration of hydrogen peroxide at 24 h of activation time. The experimental data were further evaluated through Langmuir and Freundlich isotherms. The maximum 14.46 mg/g of adsorption capacity was observed through Langmuir isotherm. Moreover, adsorption kinetics was evaluated using pseudo-first-order and pseudo-second-order kinetics, and the intra-particle diffusion model. The kinetics of arsenic adsorption was best described by using the pseudo-first-order kinetics with a kinetic rate of 0.621 min-1. The hematite iron ore before and after arsenic adsorption was characterized by XRD, SEM, and EDX.

Experimental study and dynamic simulation of melanoidin adsorption from distillery effluent.

This work aims to utilize fly ash from a thermal power station for melanoidin reduction from distillery effluent by adsorption. To accomplish this, coal fly ash was modified through chemical treatment and was then tested for melanoidin adsorption as a function of various melanoidin concentrations, contact time, and pH. The specific novelty of this study is the evaluation of coal fly ash as a low-cost adsorbent for melanoidin removal. Furthermore, the simulation study was carried out using Aspen ADSIM software in order to optimize the commercial usage of the prepared adsorbent. The main results achieved include the maximum removal efficiency of 84% which was reached at initial melanoidin concentration of 1100 mg L-1 (5% dilution), pH 6, and a contact time of 120 min. The Langmuir and Freundlich isotherm models were used to evaluate adsorption isotherms. The maximum adsorption capacity of 281.34 mg/g was observed using the Langmuir isotherm. Furthermore, pseudo-first- and pseudo-second-order and intra-particle diffusion models were used to fit adsorption kinetic data. The pseudo-second-order was best describing the adsorption kinetic with a faster kinetic rate of 0.142 mg g-1 min-1. CFA (coal fly ash) after acidic activation resulted in a slightly higher surface area, average pore volume, and pore size. The maximum breakthrough time and adsorbent saturation time were achieved at initial melanoidin concentration of 1 mol/lit, bed height of 2.5 m, and flow rate of 50 lit/min.