Introduction/purpose: Algerian natural zeolite (denoted NZ) was modified using hydrochloric acid (HZ) and sodium hydroxide solution (NaZ). This study investigated the impact of acid and alkaline modifications on the adsorption of two cationic textile dyes (BR46 and BY13) from aqueous solutions. Methods: The XRF analysis confirmed that SiO2 is the predominant mineral in all three zeolites. The XRD results revealed that NZ is primarily composed of mordenite, with chabazite and minor quartz content. The MEB-EDX analysis showed slight variations in the Si and Al content for HZ and NaZ, without significantly altering the zeolite’s structure.. The effects of initial dye concentration, contact time and pH were examined in a batch system.

Results: The adsorption on NZ, NaZ and HZ increased with longer contact times, higher initial dye concentrations, and elevated temperatures. Equilibrium was rapidly attained best described using the pseudo-second order kinetic model. Both the Langmuir and the Freundlich isotherm models fit for the adsorption data. Conclusion: The highest dye removal efficiency was observed for NaZ, with 97.62% for BR46 and 98.97% for BY13. The lowest removal rates occurred at pH= 8 for HZ and pH=10 for NZ and NaZ. Adsorption was spontaneous and endothermic.

Introduction purpose: As population growth and industrial expansion continue, surface freshwater reservoirs such as dams have become increasingly vital due to their accessibility and ease of treatment. However, the quality of these water sources has significantly deteriorated, primarily due to the discharge of domestic and industrial wastewater. The proliferation of extensive algal blooms has led to significant challenges in maintaining drinking water quality and raised concerns about public health. This study investigates the impact of various water sources on the physicochemical quality of an Algerian dam over four seasons (December 2020 – October 2021) and explores the factors influencing the occurrence of cyanobacterial blooms to better understand and manage this excessive growth.

Methods: Physicochemical properties and algal composition of the dam water were analyzed monthly to determine nutrient sources and environmental factors affecting cyanobacterial proliferation. Results: The analysis revealed that the Timgad stream and Reboua valley are notable sources of nutrient enrichment. Elevated temperatures and high nutrient loads, particularly total phosphorus (TP), in Timgad dam water facilitate the proliferation of blue-green algae. Additionally, limited nitrogen content favors the dominance of nitrogen-fixing cyanobacteria such as Aphanizomenon and Oscillatoria. The study also highlights that the low flow rate and high nutrient load of the Timgad stream create favorable conditions for cyanobacterial growth. Conclusions: Nutrient inputs, temperature, and hydrological conditions significantly influence cyanobacterial blooms. Understanding these factors is crucial for implementing effective water management strategies to reduce algal proliferation and protect freshwater quality.

Polluted water poses significant health risks when it is part of the water sources used for irrigation, leading to the contamination of soil and plants by various pollutants. This work aims, firstly, to assess the degree of pollution of Wadi El Gourzi water (Batna, Algeria), and then to verify the consequences on their use for the irrigation of market garden plants for everyday consumption (lettuce, cilantro, parsley and spinach), both in the aerial part (stems and leaves) and in the soil where they are grown. This study focuses on trace metals (Cr, Pb, Zn and Cd). Soil pollution was assessed by calculating the soil pollution index (PI), while the uptake of these elements by plants was monitored by the transfer factor (TF). The analyses of the Wadi El Gourzi water with the flame atomic absorption spectrophotometer (FAAS) show a maximum abnormal concentration of Cr (17.37 mg∙dm–3), Pb (0.71 mg∙dm–3) and Cd (0.45 mg∙dm–3). For the analysis of the soils irrigated by these waters, the results of the PI show that the soils used for the cultivation of parsley and lettuce are polluted by several metals (PI > 1). The concentrations of trace metals elements (TMEs) in the sampled plants show a significant accumulation of Zn, Cd, Pb and Cr by the vegetables (coriander, parsley, spinach and lettuce). These concentrations are above the permitted standards.

The Mio-Plio-Quaternary groundwater of Mchira-Teleghma suffers from an increasing rate of salinity especially in the northwestern part. To identify the reason for the water’s salinity and its aptitude for irrigation, physico-chemical analyses of 20 water samples, which were based on the different physical and chemical parameters (electric conductivity EC, pH, Ca²⁺, Mg²⁺, Na⁺, K⁺, HCO₃⁻, Cl⁻, SO₄²⁻, NO₃⁻ and Sr²⁺), were carried out during the period of October 2015. This study showed disquieting anomalies of electric conductivity that reached the value of 4376.14 µS cm⁻¹. The statistical analyses, the multivariate statistics: the principal component analysis, Q-mode cluster analyses, Sr²⁺/Ca²⁺ ratio and water type showed that the hydrochemistry of Mchira-Teleghma groundwater is controlled by the dissolution of carbonate rocks and the leaching of evaporite processes, which proved that these anomalies of the MPQ groundwater’s salinity of Mchira-Teleghma are mainly determined by the leaching of Triassic gypsum formations process. This hydrogeochemical process generates an unsuitable quality of water based on Wilcox’s and Water Quality Index’s methods, whereas Richard’s method classifies all water samples to C3S1 and C4S1 classes as they are recommended to be used with salt-tolerant species in well-drained and leached soils.