Using principal component analysis to distinguish sources of radioactivity and nitrates contamination in Southern Tunisian groundwater samples

Journal of Geochemical Exploration, Journal Year: 2025, Volume and Issue: unknown, P. 107670 - 107670

Published: Jan. 1, 2025

Language: Английский

Impacts of Natural Organic Matter and Dissolved Solids on Fluoride Retention of Polyelectrolyte Multilayer-Based Hollow Fiber Nanofiltration Membranes

Membranes, Journal Year: 2025, Volume and Issue: 15(4), P. 110 - 110

Published: April 2, 2025

This study examines the effects of natural organic matter (NOM) and dissolved solids on fluoride (F−) retention in polyelectrolyte multilayer-based hollow-fiber nanofiltration membranes (dNF40). Lab-scale filtration experiments were conducted under varying operating conditions (initial salt concentration, NOM permeate flux, crossflow velocity, recovery rate). dNF40 exhibited F− above 70% ± 1.2 absence competing ions. However, when filtering synthetic model water (SMW) designed to simulate groundwater contaminated with high total (TDSs) NOM, decreased approximately 60% 0.7, which was generally attributed ion competition. Furthermore, despite limited declines normalized permeability, addition SMW notably deceased steady state to~20% due fouling effects. The facilitated transport divalent cations Ca2+ Mg2+ could be observed, as they accumulated layer. While SO42− remained relatively stable, monovalent anions (NO3−, Cl−, F−) substantially drag Na+ improved slightly maintain electroneutrality. Feed salinity shown significantly affect separation efficiency, PEC layers undergoing swelling certain structural changes ionic strength increased. During batch at rates, further decreased, reducing just ~10% a 90% rate. provides valuable insights into better understanding optimizing performance PEC-based NF across diverse treatment scenarios.

Language: Английский

A Systematic Review of the Current State of Numerical Groundwater Modeling in American Countries: Challenges and Future Research

Hydrology, Journal Year: 2024, Volume and Issue: 11(11), P. 179 - 179

Published: Oct. 25, 2024

In arid and semi-arid regions, groundwater is often the only available water source. However, overexploitation pollution have led to a decrease in quantity quality. Therefore, proper management of resources essential promote sustainable development. Numerical simulation models (NSMs) emerged as valuable tool address these challenges due their ability accurately efficiently model systems. This study provides comprehensive systematic review evaluate current knowledge on using numerical flow for planning resource countries American region. A total 166 research articles were published between years 2000 2024. We analyzed summarized details such methods applied software, performance metrics, modeling units, limitations, prediction scenarios. addition, we discuss alternatives constraints difficulties suggest recommendations future research. The continued research, improvement, development are ensure sustainability resources.

Language: Английский