https://hdl.handle.net/10259/6169 2026-06-02T02:34:03Z https://hdl.handle.net/10259/11774 Optimizing Physical Factors for the Ammonium Removal from Wastewater Using Bio-Electrochemical Systems Sharma, Aparna; Gurung, Anup; Mehdi, Syed Ejaz Hussain; Shahzad, Suleman; Hussain, Fida; Kang, Woochang; Pandey, Sandesh; Khan, Aqib Hassan Ali; Oh, Sang-Eun Waste streams, leachates, and wastewater often contain high-strength ammonia, which can be challenging to manage. Microbial fuel cells (MFCs) offer a promising solution for treating such a nuisance of high-strength ammonia. However, optimizing MFC operating conditions, at lower technology readiness levels, is crucial to achieve a sustainable and economically viable application. This study investigates the factors affecting ammonia nitrogen removal in MFCs. MFCs with a cation exchange membrane (CEM) exhibit a higher diffusion rate of ammonium ions from the anode to the cathode compared to those with a proton exchange membrane (PEM). In close circuit mode (CCM), MFCs with a Pt-coated cathode electrode achieved an ammonium removal efficiency of 96% in the cathode chamber. Moreover, a plain carbon cathode electrode yielded an 87.1% removal efficiency. These results indicate that the combination of a catalyst (Pt) and oxygen in the cathode chamber can effectively remove or recover ammonia nitrogen from wastewater. Simultaneously, the removal of ammonia nitrogen in a microbial electrolysis cell (MEC) was studied. At an applied potential of 1.0 V, an ammonium removal efficiency of 87.5% was achieved. It was concluded that ammonium losses in MFCs can occur through electron migration, volatilization, and biological processes such as nitrification and denitrification 2025-03-01T00:00:00Z https://hdl.handle.net/10259/11773 Sustainable management of post-phytoremediation biomass Mukherjee, Santanu; Leri, Alessandra C.; Bandaranayaka, Chathurika; Vázquez-Núñez, Edgar; Barros García, Rocío; Khan, Aqib Hassan Ali; Zhou, Pingfan; Zhang, Tao; Bernal, M. Pilar; Clemente, Rafael; Bolan, Nanthi Organic and inorganic contaminants are entrained into environmental systems through natural and anthropogenic processes, such as mining activities, manufacturing, and waste disposal. In terrestrial and aquatic environments, the contaminant(s) remediation can be achieved by immobilization, thereby inhibiting their dispersal and bioavailability. Mobilization, through leaching and plant uptake, is another process of pollutant removal. Phytoremediation has attracted attention as an eco-friendly alternative for the remediation of contaminated environments. However, the safe management of post-phytoremediation contaminated biomass poses many practical challenges. Understanding the fate of the pollutants in the plants allows the estimation of the possible transfer of the contaminants to the food chain ascertain by-products or residues during biofuel production. Metal-enriched fractions could be used as a valuable source of novel catalysts or reusable materials. The safe conversion of biomass into energy may require sequestering contaminants at any step of the process, preferably upstream of the energy conversion or as a pre-treatment of plant biomass. Through gasification or pyrolysis of post-remediation biomass, bioenergy products (including syngas, oil, hydrogen gas, biochar, and hydrochar) can be used for heating and electricity generation. A comparative evaluation among pyrolysis, gasification, combustion, and liquefaction/fermentation processes for biofuel production from post-phytoremediation biomass suggests that pyrolysis is the strategy with the lowest transfer of toxic metals to the final products. This review presents critical discussions of the processes involved in phytoremediation of contaminated environments, the redistribution of contaminants within plant biomass, the sustainable management of post-phytoremediation biomass, and the unintended environmental consequences of phytoremediation 2025-12-01T00:00:00Z https://hdl.handle.net/10259/11772 Assessing Recharge Zones for Groundwater Potential in Dera Ismail Khan (Pakistan): A GIS-Based Analytical Hierarchy Process Approach Tabassum, Anwaar; Sajjad, Asif; Sajid, Ghayas Haider; Ahmad, Mahtab; Iqbal, Mazhar; Khan, Aqib Hassan Ali Groundwater constitutes the primary source of liquid freshwater on Earth and is essential for ecosystems, agriculture, and human consumption. However, rising demand, urbanization, and climate change have intensified groundwater depletion, particularly in semi-arid regions. Therefore, assessing groundwater recharge zones is essential for sustainable water resource management in vulnerable areas such as Dera Ismail Khan, Pakistan. This study aims to delineate groundwater potential zones (GWPZs), using an integrated approach combining the Geographic Information System (GIS), remote sensing (RS), and the analytical hierarchy process (AHP). Twelve factors were identified in a study conducted using GIS-based AHP to determine the groundwater recharge zones in the region. These include land use/land cover (LULC), rainfall, drainage density, soil type, slope, road density, water table depth, and remote sensing indices such as Normalized Difference Vegetation Index (NDVI), Normalized Difference Built-up Index (NDBI), Moisture Stress Index (MSI), Worldview Water Index (WVWI), and Land Surface Temperature (LST). The results show that 17.52% and 2.03% of the area have “good” and “very good” potential for groundwater recharge, respectively, while 48.63% of the area has “moderate” potential. Furthermore, gentle slopes (0–2.471◦ ), high drainage density, shallow water depths (20–94 m), and densely vegetated areas (with a high NDVI) are considered important influencing factors for groundwater recharge. Conversely, areas with steep slopes, high temperatures, and dense built-up areas showed “poor” potential for recharge. This approach demonstrates the effectiveness of integrating advanced remote sensing indices with the AHP model in a semi-arid context, validated through high-accuracy field data (Kappa = 0.93). This methodology offers a cost-effective decision support tool for sustainable groundwater planning in similar environments 2025-06-01T00:00:00Z https://hdl.handle.net/10259/11763 Thymol-Based Natural Deep Eutectic Solvents under Pressure: A Novel Platform for Green Solvents Ozkilinc, Ozge; Bol Arreba, Alfredo; Soler, Miguel Angel; Fogolari, Federico; Aparicio Martínez, Santiago Deep eutectic solvents (DESs) are emerging green alternatives to traditional solvents, yet their behavior under high pressure (HP) remains underexplored. This study examines two thymol-based eutectic mixtures─thymol:1,8-cineole (1:1) and thymol:camphor (1:1)─using a combined experimental and molecular dynamics approach. Pressure–volume–temperature (PVT) measurements were conducted across 0.1–60 MPa and 293.15–343.15 K. The two systems displayed expected density trends but exhibited markedly different internal pressure responses: a maximum for the camphor system and a shallow minimum for the cineole mixture. Molecular dynamics simulations revealed more frequent hydrogen bonding and greater structural organization in the camphor system, highlighting how molecular structure affects interactions. Changes in hydrogen bonding and internal pressure remained within 25% over the entire pressure range. These results provide molecular-level insight into pressure effects on DESs, guiding their future application in chemical processing and materials science under nonambient conditions 2025-09-01T00:00:00Z