Surface water is used for a variety of purposes, including agriculture, drinking water, and other services. Therefore, its quality is crucial for irrigation, human welfare, and health. Thus, the main objective is to improve surface water quality assessment and geochemical analysis to evaluate anthropogenic activities’ impact on surface water quality in the Oued Laou watershed, Northern Morocco. Thirteen surface water samples were characterized for 26 physicochemical and biological parameters. In this aspect, emerging techniques such as multivariate statistical approaches (MSA), water quality indices (WQI), irrigation water quality (IWQI), and Geographic Information System (GIS) were employed to identify the sources of surface water pollution, their suitability for consumption, and the distribution of surface water quality. The results showed that the major ion concentrations were reported in the following order: Ca²⁺, Na⁺, Mg²⁺, and K⁺; and HCO₃⁻ > CO₃²⁻ > Cl⁻ > SO₄²⁻ > NO₃⁻ > F⁻ > PO₄³⁻ > NO₂⁻. It was also demonstrated that almost all parameters had concentrations lower than World Health Organization (WHO) limits, except for bicarbonate ions (HCO₃⁻) and the biochemical oxygen demand for five days (BOD₅), which exceeded the WHO limits at 120 mg/L and 3 mg/L, respectively. Furthermore, the types of Ca²⁺-HCO₃⁻ (Calcium-Bicarbonate) and Ca²⁺-Mg²⁺-HCO₃⁻ (Calcium-Magnesium-Bicarbonate) predominated in surface water. The Principal Component Analysis (PCA) indicates that the Oued Laou river was exposed to two forms of contamination, the first being attributed to anthropogenic activities such as agriculture, while the second reflects the water-sediment interaction. The Hierarchical Cluster Analysis (HCA), reflecting the mineralization in the study area, has classified the samples into four clusters. The Inverse Distance Weighting (IDW) of the WQI indicates that 7.69% and 38.46% of the surface water represent, respectively, excellent and good quality for drinking. At the same time, the IWQI revealed that 92.30% of the water surface is good for irrigation. As a result, the combination of WQIs, PCA, IWQI, and GIS techniques is effective in providing clear information for assessing the suitability of surface water for drinking and its controlling factors and can also support decision-making in susceptible locations such as the Oued Laou river in northern Morocco.

The relationship between agricultural activities, soil characteristics, and groundwater quality is critical, particularly in rural areas where groundwater directly supplies local people. In this paper, three agricultural sandy soils were sampled and analyzed for physicochemical parameters such as pH, water content, bulk density, electrical conductivity (EC), organic matter (OM), cation exchange capacity (CEC), and soil grain size distribution. Major and trace elements were analyzed by inductively coupled plasma-optical emission spectrometry (ICP/OES) to determine their concentrations in the fine fraction (FF) of the soils. Afterward, the elemental composition of the soils was identified by X-ray powder diffraction (XRD) and quantified by X-ray fluorescence (XRF). The surface soil characteristics were determined by the Brunauer–Emmett–Teller (BET) method, whereas the thermal decomposition of the soils was carried out using thermogravimetric analysis and differential scanning calorimetric (TGA-DSC) measurements. The morphological characteristics were obtained by scanning electron microscopy (SEM). Afterward, column-leaching experiments were conducted to investigate the soil’s retention capacity of nitrate (NO⁻₃). Parallelly, a chemical and physical study of olive pomace biomass slag (OPBS) residue was carried out in order to explore its potential use as a soil additive and improver in the R’mel area. The OPBS was characterized by physicochemical analysis, assessed for heavy metals toxicity, and characterized using (XRD, XRF, SEM, and BET) techniques. The results show that the R’mel soils were slightly acidic to alkaline in nature. The soils had a sandy texture with low clay and silt percentage (<5% of the total fraction), low OM content, and weak CEC. The column experiments demonstrated that the R’mel irrigated soils have a higher tendency to release large amounts of nitrate due to their texture and a higher degree of mineralization which allows water to drain quickly. The OPBS chemical characterization indicates a higher alkaline pH (12.1), higher water content (7.18%), and higher unburned carbon portion (19.97%). The trace elements were present in low concentrations in OPBS. Macronutrients in OPBS showed composition rich in Ca, K, and Mg which represent 10.59, 8.24, and 1.56%, respectively. Those nutrients were quite low in soil samples. Both XRD and XRF characterization have shown a quasi-dominance of SiO₂ in soil samples revealing that quartz was the main crystalline phase dominating the R’mel soils. Oppositely, OPBS showed a reduced SiO₂ percentage of 26,29% while K, Ca, and P were present in significant amounts. These results were confirmed by XRF analysis of OPBS reporting the presence of dolomite (CaMg, (CO₃)₂), fairchildite (K₂Ca (CO₃)₂), and free lime (CaO). Finally, the comparison between the surface characteristic of OPBS and soils by BET and SEM indicated that OPBS has a higher surface area and pore volume compared to soils. In this context, this study suggests a potential utilization of OPBS in order to (1) increase soil fertility by the input of organic carbon and macronutrients in soil; (2) increase the water-holding capacity of soil; (3) increase soil CEC; (4) stabilize trace elements; (5) enhance the soil adsorption capacity and porosity.

High-level findings on the deep-sea capacity of 186 geographical areas, divided into six global regions: Europe, Asia, Northern America, Africa, Oceania, and Latin America & the Caribbean.

Mediterranean countries experience a large production of olive oil, thus generating huge quantities of non-biodegradable vegetation waters. The discharge of these effluents into aquatic environments seriously affects the quality of surface waters. This study investigated the potential use of carbon steel slag (SS) as an adsorbent and improver for reducing olive mill wastewater (OMWW) toxicity. The elemental and structural characterization of SS was carried out using inductively coupled plasma-optical emission spectrometry (ICP/EOS), X-ray fluorescence (XRF), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and Brunauer–Emmett–Teller (BET) analysis. OMWW characterization indicated that the effluent was acidic in nature, with a pH of 4.8, a higher conductivity reaching 14.92 mS/cm, higher COD of 157.31 g/L, rich in organic matter 112.33 g/L, and total phenolic compounds of 11.13 g/L. The neutralization capacity of SS was demonstrated by reducing the OMWW’s acidic character. Afterward, the adsorption of tannic acid (TA) was investigated using SS. Parameters such as contact time, initial TA concentration, adsorbent dosage, pH, and temperature were investigated. The kinetic study indicated that the adsorption of TA onto SS fitted well with the second pseudo-order (r = 0.99) and Elovich (r = 0.98) models, indicating that the adsorption of TA was mainly chemical and depends on the reactions of oxide hydrolysis and hydroxides dissolution. Moreover, Langmuir isotherm has greatly described the adsorption of TA on SS (R = 0.997), suggesting that the surface of SS is homogenous, and the adsorption occurs mainly in monolayer. The maximum adsorption capacity reached 714.28 mg/g, indicating the higher capacity of SS to reduce the polyphenolic compounds in OMWW. This study demonstrated that SS residue from the steelmaking industry could present a highly interesting material for OMWW remediation.

This research provides the first assessment of the leachate impact on water sources near the newly installed Landfill and Recovery Center (LRC) in Tangier, Morocco, which has been operational since the beginning of 2021. The investigation involved the analysis of microbiological and chemical...