Ahmad Jamrah

Olive mill wastewater (OMW) is a major environmental concern in olive-producing regions because of its high organic load and phytotoxic phenolic content, which limit its safe discharge or reuse. This study aimed to develop and evaluate an integrated electrocoagulation–adsorption (ECAD) treatment using olive pomace (OP) biochar and to determine how electrode material influences the performance and cost of the combined process. Specifically, the study characterized OP biochar produced by pyrolysis and evaluated its adsorption behavior toward total phenols (TPh) and soluble chemical oxygen demand (COD _soluble ), compared Al- and Fe-based EC and their integrated ECAD performance, and theoretically determined biochar dosages and estimated the operational cost of both configurations. The produced biochar exhibited a BET surface area of 135.23 m ² /g, a mesoporous structure with an average pore width of 21.95 Å, a negative zeta potential of −29.89 mV, and a carbon content of 67.21%, confirming the formation of a carbon-rich and porous adsorbent. Isotherm analysis showed that TPh adsorption was best described by the Langmuir model, with a maximum adsorption capacity of 84.74 mg/g, whereas COD _soluble was best fitted by the Dubinin–Radushkevich (D–R) model. Standalone EC achieved comparable TPh and COD _soluble removal using Al and Fe electrodes (about 52–55%). However, the integrated systems showed a strong electrode-dependent response. The Al-ECAD system achieved maximum removals of 70.69% TPh and 71.39% COD _soluble , while the Fe-ECAD system reached 67.40% and 66.33%, respectively, at the lowest biochar dosage, with removal declining at higher dosages. The estimated operational costs were 4.25 and 5.30 US$/m ³ for Al- and Fe-based systems, respectively. The novelty of this work lies in demonstrating that the effectiveness of biochar-assisted EC is strongly dependent on electrode–biochar compatibility, identifying electrode selection as a key design factor for ECAD treatment of OMW.

Olive mill solid waste (OMSW) is a major by-product of the agro-industrial sector and can be converted into biochar through pyrolysis, with potential applications in environmental management. This study investigated the effects of pyrolysis temperature (400, 500, and 600 °C) and residence time (1, 3, and 5 h) on the physicochemical, structural, and surface properties of OMSW-derived biochar. As the temperature increased, the biochar yield decreased from 32.08% at 400 °C (1 h) to 25.18% at 500 °C (1 h) and 24.67% at 600 °C (1 h). Surface area and pore development varied considerably with the processing conditions. At 500 °C, the BET surface area increased from 6.99 m²/g at 1 h to 44.19 m²/g at 5 h, accompanied by an increase in total pore volume from 0.006 to 0.026 cm³/g. At 600 °C, the maximum Langmuir surface area (201.6 m²/g) and total pore volume (0.075 cm³/g) were obtained at 1 h, whereas the BET surface area reached 135.23 m²/g at 5 h. These differences indicate that residence time influenced the measured surface area and pore characteristics differently. Moisture content reached 4.18% at 600 °C for 5 h, while ash content reached 10.83% under the same conditions. Moisture content varied with temperature and residence time, reaching 4.18% at 600 °C for 5 h. Ash content also reached its maximum value of 10.83% under these conditions, while electrical conductivity reached 0.077 mS/cm. All biochar samples exhibited negative zeta potentials, ranging from −22.72 to −32.21 mV at 400 and 500 °C, while values at 600 °C ranged from −23.53 to −29.89 mV. Elemental analysis revealed variations in the H/C and O/C atomic ratios, with H/C values ranging from 0.2468 to 0.5984 and O/C values ranging from 0.0369 to 0.296. These variations indicate differences in elemental composition and relative carbonization characteristics among the samples. Calcium and potassium were the predominant mineral elements. Overall, the findings provide a basis for further investigating OMSW-derived biochar for potential adsorption, soil-related, and nutrient-management applications, subject to application-specific experimental validation.

Introduction: Olive mill wastewater (OMW) is characterized by a high organic load and complex composition, requiring efficient and sustainable treatment strategies. This study investigates the potential of biochar (BC) derived from olive mill solid waste (OMSW) as an adsorbent for the removal of total phenols (TPh) and chemical oxygen demand (COD) from OMW. Methods: OMSW-derived BC was produced by slow pyrolysis at 600°C for 5 h and characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The BC exhibited a carbon content of 67.21%, a BET surface area of 135.2 m ² /g, and a total pore volume of 0.0055 cm ³ /g. Batch adsorption experiments were conducted to evaluate the effects of contact time, BC dosage, and temperature. Adsorption kinetics, isotherms, and thermodynamic parameters were evaluated using established models. Results: TPh adsorption followed a pseudo-second-order kinetic model with an excellent fit (R ² = 1), whereas COD showed a weaker fit (R ² = 0.76), indicating more complex adsorption behavior. Increasing the BC dosage from 0.05 to 0.5 g resulted in only limited improvements in removal efficiency, with COD removal increasing from 73.79% to 77.45% and TPh removal from 75.87% to 79.30%. Temperature significantly affected adsorption performance. COD removal reached 75.61% at 25°C and 79.46% at 35°C. TPh removal from OMW increased from 0.12% at 25°C to 19.15% at 35°C and reached 24% at 45°C. For the gallic acid (GA) solution, TPh removal reached 72.28% at 35°C before declining at 45°C. Isotherm analysis showed that the Freundlich model provided a better description of TPh adsorption at elevated temperatures, with R ² = 0.9833 at 45°C. Thermodynamic analysis indicated that TPh adsorption was spontaneous and endothermic (ΔH° = +71.37 kJ/mol), with negative entropy suggesting increased ordering at the BC surface. Discussion: The results demonstrate that OMSW-derived BC has potential as a sustainable adsorbent for the treatment of OMW, particularly for the removal of COD and phenolic compounds. The conversion of OMSW into BC provides an approach for valorizing an agricultural waste stream while producing an adsorbent with useful physicochemical properties. These findings support the potential application of agricultural waste-derived BC in targeted OMW treatment and contribute to more sustainable wastewater management practices in the olive oil sector.

The growing complexity and variability of industrial wastewater (IWW) require treatment strategies that can support reliable prediction, monitoring, optimization, and operational decision-making. Artificial intelligence (AI) and machine learning (ML) have increasingly been applied to these functions; however, the literature remains fragmented across pollutants, treatment processes, and modeling approaches. This study presents a critical bibliometric review of 151 Scopus-indexed publications on AI/ML applications in IWW treatment published between 2016 and 2025. Publication output increased substantially, reaching 35 publications in 2024 and 67 in 2025, compared with 1–4 publications annually during 2016–2019. China was the leading contributor with 54 publications, followed by India with 26, while Saudi Arabia and the United States each contributed 15. The main research directions included prediction and soft sensing, process optimization and control, monitoring and digitalization, adsorption and material-based treatment, membrane processes, and advanced oxidation and degradation. Artificial neural networks, support vector machines, random forests, and hybrid models were among the most frequently applied techniques. Study-level assessment of 38 technically assessable original AI/ML applications showed that 34 studies (89.5%) relied on offline or retrospective model evaluation, whereas only four (10.5%) demonstrated online or real-time AI/ML evaluation or operation. Conventional internal validation predominated among studies for which validation design could be established, while independent temporal, cross-domain, cross-scale, or field-based validation remained comparatively uncommon. Laboratory- and bench-scale applications were common, although several studies used full-scale industrial data. Major barriers to practical deployment include limited transferability across wastewater matrices, insufficient field-scale validation, inconsistent sensor and data quality, limited interpretability, and weak integration with treatment-plant control systems. Chemical oxygen demand soft sensing, pH and chemical-dosing support, and real-time monitoring and anomaly detection represent promising pathways for near-term implementation, while closed-loop control requires stronger validation of reliability, safety, and long-term performance. Overall, the field is transitioning from isolated, model-centered research toward system-level deployment, where transferability, validation, interpretability, and control integration are as important.

This study evaluated the potential of biochar (BC) produced from olive mill solid waste (OMSW) for methylene blue (MB) removal from synthetic solutions. BC was prepared at pyrolysis temperatures of 400 °C, 500 °C, and 600 °C for residence times of 1, 3, and 5 h. The produced BCs were characterized using BET, SEM, FTIR, XRD, zeta potential, and elemental analysis, while adsorption performance was assessed through equilibrium, kinetic, and thermodynamic studies. The results demonstrated that increasing pyrolysis temperature improved the physicochemical properties of BC. The BET surface area increased from 1.34–1.9 m²/g at 400 °C to 135.23 m²/g at 600 °C, accompanied by enhanced pore volume and the development of a highly porous structure observed by SEM. FTIR analysis revealed progressive transformation of oxygen-containing functional groups, while XRD indicated increased structural ordering and carbonization at higher pyrolysis temperatures. BC produced at 600 °C exhibited the highest adsorption performance, achieving a maximum MB removal efficiency of 99.57% and an adsorption capacity of 17 mg/g. Adsorption kinetics were best described by the pseudo-second-order model (R² > 0.99), indicating strong adsorbate–adsorbent interactions. Equilibrium results were best fitted by the Langmuir isotherm with a maximum R² of 0.9963, suggesting predominantly monolayer adsorption, whereas the Freundlich model showed a maximum R² of 0.9788 under elevated temperature and prolonged contact conditions, indicating surface heterogeneity and multilayer adsorption. Thermodynamic analysis confirmed that MB adsorption was spontaneous (ΔG° = −38.61 to −47.57 kJ/mol), predominantly endothermic (ΔH° up to 4.11 kJ/mol), and associated with increased randomness at solid–solution interface (ΔS° > 0). Overall, BC produced at 600 °C for 3–5 h exhibited the most favorable structural characteristics and adsorption performance, highlighting its potential as a sustainable and low-cost adsorbent for wastewater treatment applications.

This research employed “Response Surface Methodology (RSM)” to assess the effectiveness of electrocoagulation (EC) in treating olive mill wastewater (OMW) before applying adsorption with olive stone biochar (OS) as a sustainable adsorbent. Several parameters, including reaction time, current density (CD), inter-electrode distance, and the number of electrodes, were optimized. Analysis using Minitab 22.2 resulted in robust regression models with high coefficients of determination (R²). The optimal parameters were CD of 12.41 mA/cm², a time of 45.61 min, an inter-electrode spacing of 1 cm, and a maximum of 6 electrodes, resulting in an energy consumption (ENC) of 9.85 kWh/m³. Significant pollutant percentage removals were achieved: 72.32% for total Kjeldahl nitrogen (TKN), 80.74% for turbidity, 57.44% for total phenol (TPh), 56.9% for soluble chemical oxygen demand (COD_soluble), and 56.6% for total chemical oxygen demand (COD_total). After the EC, the adsorption of pollutants was conducted using OS biochar that was generated through the pyrolysis of OS at a temperature of 500 °C. FTIR analysis of the biochar revealed key absorption bands that indicated the presence of inorganic compounds, aromatic C=C, and phenolic groups O-H. The integrated EC and adsorption (ECA) process demonstrated markedly higher efficiencies, with TPh removal reaching 61.41%, turbidity reduction at 81.92%, TKN reduction at 77.78%, COD_soluble reduction at 70.31%, COD_total reduction at 65.1%, and project cost of $2.88/m³. The ECA process presents a promising treatment approach for OMW.

This study investigates the effectiveness of electrocoagulation (EC) with locally sourced iron electrodes for treating olive mill wastewater (OMW) prior to adsorption with olive stone (OS). Using Response Surface Methodology (RSM), 60 experiments were conducted to evaluate various operational parameters, including current density (CD), reaction time (T), distance between electrodes (D), and the number of electrodes (N). The optimal conditions identified were a reaction time of 53.49 min, a current density of 15.1104 mA/cm², 1 cm electrode spacing, and six electrodes. Under these conditions, the removal efficiencies achieved were 54.46% for total phenols (TPh), 73.25% for total Kjeldahl nitrogen (TKN), 92% for turbidity, 58.91% for soluble chemical oxygen demand (COD_soluble), and 58.55% for total COD (COD_total), with an energy consumption of 14.3146 kWh/m³ and a projected cost of USD 3.92/m³. Following the EC process, the treated OMW underwent further adsorption using OS, enhancing pollutant removal. The combined EC and adsorption (ECA) method demonstrated superior performance, achieving TPh removal at 62.63%, TKN removal at 77.52%, and turbidity reduction at 83.73%. Additionally, COD_total removal increased to 72.88% with COD_soluble removal at 70.04%. This integrated approach significantly improves pollutant removal, presenting a promising solution for effective OMW treatment.

The use of treated wastewater (TWW) in agriculture is an important technological alternative for decreasing freshwater consumption and improving soil physicochemical and biological properties. The aim of this study was to investigate how the quality of soil and olive plants was affected by irrigation with TWW, surface water (SW), and blended water (BW), using tap water as the control. Several plant growth, chemical, and microbial parameters, namely plant height, trunk diameter, chlorophyll content, pH, total organic carbon (TOC), total nitrogen (TN), metals, salinity, and microbial population were selected for this purpose. The short-term irrigation of olive plants for 3 years with TWW, BW, and SW increased the electrical conductivity, TOC, TN, phosphorus, and potassium in the soil. There were notable differences in plant height and chlorophyll content observed in the third year of the experiment, with the greatest values found for the TWW-irrigated plants. These differences were attributed to the rise in the TOC and TN in the soil, which promoted rapid plant growth. The reduction in microbial contamination during the cold seasons may indicate the natural control of these harmful pathogens. Accordingly, it can be concluded that the blending of TWW with SW can reduce the negative effects of TWW resulting from the accumulation of TOC, TN, and metals.

The study investigates the economic feasibility and farmer acceptance of utilizing treated wastewater (TWW) for agricultural irrigation, particularly in the Northern Jordan Valley. Despite its potential to mitigate water scarcity, concerns persist regarding its impact on soil health, crop yield, and land utilization, hindering widespread adoption. The research aims to measure farm profitability and farmers' willingness to embrace TWW through various blending scenarios with traditional surface water sources. The yield response function to salinity was incorporated into profit function to simulate crop profitability and water values. Results indicate that the introduction of TWW negatively affects salt-sensitive crops like citrus but positively impacts others such as date palm, olives, tomatoes, and peppers due to increased fertilizer content in irrigation water. Economic performance indicators reveal a gradual decrease in water net productivity for citrus with increasing blending ratios of TWW, with the water value decreasing accordingly. Higher percentages of treated water do not consistently lead to increased productivity, profitability, or net value added, emphasizing the need for careful consideration and understanding of economic risks associated with specific crops and water quality. To mitigate the impact of water salinity on citrus production, growers are advised to improve soil quality, periodically flush the soil with low-salinity water, and use salt-tolerant rootstocks. Regular monitoring of soil and water salinity levels is crucial for informed decision-making. While using TWW, water may offer cost savings.

Water footprint (WF) analysis is crucial for comprehending agricultural water usage patterns. This study aims to determine the total WF for tomatoes in Jordan from 1994 to 2023, covering both summer and winter seasons, to inform decision-making regarding tomato cultivation practices in the area. Despite inconsistencies in data recording, particularly regarding fertilizer application and sunshine, the WF serves as a valuable tool for estimating seasonal variations in water requirements and facilitating comparisons between different approaches to water usage for tomatoes. Comparative studies globally suggest variability in WFs due to factors such as climate, irrigation methods, and soil conditions influencing results. In this study, the CROPWAT 8.0 model was employed to analyze input data obtained from the Department of Statistics, NASA POWER, and local farmers near the Baqoura, Deir Alla, and Ghour Alsafi stations. The analysis aimed to determine the green WF (rainfall), blue WF (irrigation), and gray WF (water required to dilute pollutants) at these stations. The results revealed that the total WF during winter was approximately 7217.62, 8417.65, and 14061.42 m3/ton for the Baqoura, Deir Alla, and Ghour Alsafi stations. In summer, the respective values were around 3107.67, 6026.52, and 11847.35 m3/ton. Significant findings include ET green, evapotranspiration (ET) blue, crop water use (CWU) green and blue, and production yield for 2023. The nitrogen application per dunum was also calculated as 368 kg/30 dunum, equating to 123 kg/ha. The significance of these results lies in their potential to inform and optimize water management practices in tomato cultivation, promoting sustainability and resource efficiency.