Mohanad J. M-Ridha

This study aimed to utilise cheap and abundantly available date palm fibre (DPF) wastes for the remediation of methylene blue (MLB) dye–contaminated groundwater. The DPF adsorbents were first prepared, followed by various characterisation analyses, including surface morphology, functional groups, and material structure. Subsequently, the DPF adsorbents were applied in the batch and continuous adsorption studies to assess the MLB dye removal from aqueous environments. The batch adsorption study achieved 98% maximum removal efficiency with a contact time, adsorbents dosage, initial pH, temperature, particle size, initial dye concentration, and agitation speed of 105 min, 3 g/L, 7.0, 45 °C, 0.075 mm, 50 mg/L, and 150 rpm, respectively. Langmuir was the best-fitted isotherm model depending on a higher correlation coefficient (R² = 0.985), with a maximum monolayer dye adsorption capacity (q_max) of 54.204 mg/g. Additionally, the second order was the best-fitted kinetic model (R² = 0.990), indicating that MLB dye was removed through chemisorption. Besides, the positive enthalpy change (ΔH°) and negative Gibb’s free energy (ΔG°) values verified the endothermic process and spontaneous adsorption. According to the impact analysis of initial dye concentrations and flow rates on the permeable reactive barrier (PRB) performance in the continuous adsorption study using the Thomas, Belter, and Yan models, the experimental results and predicted breakthrough curves reflected an excellent agreement (R² ≥ 0.8767) and a sum of squared errors (SSE) ≤ 0.4834. In short, the results demonstrated DPF as an effective adsorbent material in PRB technology.

BACKGROUND: Microbial desalination cell (MDC) is a new technology in the use of electrical energy for water desalination and wastewater treatment.RESULTS: Open circuit (OC) and closed circuit (CC) modes were successfully simulated with initial TDS concentrations of 10 g/L and 10–15 g/L, respectively (an external resistance of only 150 Ω was applied for CC). After 160 h of operation, the maximum OC voltage, desalination efficiency and COD removal efficiency were 809 mV, 32.2% and 79.2%, respectively. The maximum voltage was also obtained when the external resistances were 150 Ω (423.4 and 438 mV) for the initial NaCl concentrations (10 and 15 g/L) in the central chamber, respectively. Moreover, the maximal desalting and COD removal efficiencies after 24 h run‐time were (30% and 28%) and (24% and 25%) for initial NaCl concentrations (10 or 15 g/L) in the central chamber, respectively. Maintaining pH (8.61, 7.01) to (7.85, 7.8) in anode and cathode chambers was studied. This research accurately depicted microbial desalination's efficiency in generating OC voltages and CC electrical energy via Box–Behnken Design Distribution (BBD). Investigated factors’ interactions (initial salt/COD concentrations, time) on CC system's energy efficiency. Resulted in peak productivity at (1.85 mW), OC reaching (1100 mV).CONCLUSION: Finally, the research paper gave exciting results in improving the efficiency of the microbial desalination cell to increase the ability to produce electrical energy and desalinate water. © 2023 Society of Chemical Industry (SCI).

Levofloxacin (LEV) is an important and widely used antibiotic. It is used to treat many bacterial infections. It may be found in water sources as a result of incomplete metabolism in humans and other sources. In this study, the adsorption of Levofloxacin by raw rice husk (RRH) was investigated. The effect of pH, time, temperature, RRH weight, and initial Levofloxacin concentration on the adsorption process were determined. Kinetic, isotherm and thermodynamic models were studied to explain the Levofloxacin adsorption mechanism on raw rice husk. The results of adsorption kinetics and isotherms revealed that the adsorption of LEV by RRH was better fitted with the Intraparticle model with coefficient of determination (R²=96%), while the Langmuir model represents the best isotherm model to describe the adsorption process with (R² =95%).  The removal efficiency reached 99% , the monolayer maximum uptake q_max is 2.47 mg/g and the  adsorption intensity parameter (1/n) value is 0.763, which means that the adsorption is favorable. According to the thermodynamic coefficients, the adsorption process was spontaneous and feasible for the temperatures under investigation; the sorption efficiency was more favorable at higher temperatures, and the adsorption process is endothermic.

The pollution producing from textile industries effluents is growing since the years, due to at discharged lots of it in water without treatment. The resulting effluent is colourful, highly toxic, and poses a significant environmental hazard. This problem can be solved by using enzymic biological treatment, where the Congo red dye was used with concentrations (100,200,300,500) mg /L, pH values (3,4,5,6,7,8), and variable temperatures (25,35,45)°C, the best removal of Congo red (CR) dye under optimum conditions for degradation was at concentration of 100 mg/L, at (pH 6, 25 °C) with efficiency of 99.85 % using the peroxidase enzyme extracted from red radish plant, while the removal percentage decreased when increase dye concentration .

Seawater might serve as a fresh‐water supply for future generations to help meet the growing need for clean drinking water. Desalination and waste management using newer and more energy intensive processes are not viable options in the long term. Thus, an integrated and sustainable strategy is required to accomplish cost‐effective desalination via wastewater treatment. A microbial desalination cell (MDC) is a new technology that can treat wastewater, desalinate saltwater, and produce green energy simultaneously. Bio‐electrochemical oxidation of wastewater organics creates power using this method. Desalination and the creation of value‐added by‐products are expected because of this ionic movement. According to assessments, recent investigations on MDC configurations have led to significant changes in their operating characteristics, as well as their design and operational factors. Additionally, the study notes the expanding uses of MDC in bioremediation, nutrient recovery, water softening, and value‐added chemical manufacturing. Significant results show that the MDC system produced outstanding desalination without the need for external power, in addition to achieving wastewater treatment and energy recovery without the need for intermediary processes. When it comes to its practical application, some of the technical obstacles include keeping pH stable in cathodic and anodic fluids, increasing internal resistance using catalysts as electrode fillers, along with issues of biofouling and durability. Although MDC technology is currently being developed and scaled up, additional research on membrane fouling avoidance, material feasibility, electron transport kinetics, growth of microorganisms, and catalyst durability is needed. © 2022 Society of Chemical Industry (SCI).

A phytoremediation experiment was carried out with kerosene as a model for total petroleum hydrocarbons. A constructed wetland of barley was exposed to kerosene pollutants at varying concentrations (1, 2, and 3% v/v) in a subsurface flow (SSF) system. After a period of 42 days of exposure, it was found that the average ability to eliminate kerosene ranged from 56.5% to 61.2%, with the highest removal obtained at a kerosene concentration of 1% v/v. The analysis of kerosene at varying initial concentrations allowed the kinetics of kerosene to be fitted with the Grau model, which was closer than that with the zero order, first order, or second order kinetic models. The experimental study showed that the barley plant designed in a subsurface flow phytoremediation system would have great potential for the reclamation of kerosene-contaminated water.