The intensive consumption of pharmaceuticals and drugs in the last decades has led to their increased concentrations in wastewaters from industrial sources. The present paper deals, for the first time, with the sonochemical degradation and mineralization of furosemide (FSM) in water. FSM is a potent loop diuretic used to treat fluid build-up due to heart failure, liver scarring, or kidney disease. The influence of several operating parameters such as acoustic intensity, ultrasonic frequency, initial FSM concentration, solution's pH, nature of the dissolved gas (Ar, air and N₂) and radical scavengers (2-propanol and tert-butanol) on the oxidation of FSM was assessed. The obtained results showed that the degradation rate of the drug increased significantly with the increase of the acoustic intensity in the range of 0.83 to 4.3 W cm^-2 and decreased with the augmentation of the frequency in the range of 585-1140 kHz. It was also found that the initial rate of the sonolytic degradation of FSM increased with the increase of its initial concentration (2, 5, 10, 15 and 20 mg/L). The most significant degradation was achieved in acidic conditions at pH 2, while in terms of saturating gas, the rate of FSM degradation decreased in the order of Ar > air > N₂. The FSM degradation experiments with radical scavengers showed that the diuretic molecule degraded mainly at the interfacial region of the bubble by hydroxyl radical attack. Additionally, in terms of acoustic conditions, the sono-degradation of 30.24 µmol L^-1 of FSM solution demonstrate an optimal performance at 585 kHz and 4.3 W/cm², the results indicated that even if the ultrasonic action eliminated the total concentration of FSM within 60 min, a low degree of mineralization was obtained due to the by-products formed during the sono-oxidation process. The ultrasonic process transforms FSM into biodegradable and environmentally friendly organic by-products that could be treated in a subsequent biological treatment. Besides, the efficiency of the sonolytic degradation of FSM in real environmental matrices such as natural mineral water and seawater was demonstrated. Consequently, the sonochemical advanced oxidation process represent a very interesting technique for the treatment of water contaminated with FSM.

This paper presents several transformative scenarios of municipal solid waste landfilling sites from technical and ecological points of view, applicable to upper-middle-income countries, as per the classification of the World Bank. Our approach is based on numerical simulations of greenhouse gas (GHG) emissions in 2012 and 2025 and numerical simulations of methane emissions in a selected landfilling site, Oued Smar, in Algiers (Algerian capital city), according to the LandGem and IPCC models. Business-as-usual, landfill gas flaring, and electricity generation scenarios are considered in the numerical simulations. Finally, a novel metric dividing the recoverable electrical power by the amount of avoided greenhouse gas emissions is suggested. This paper reveals that the LandGem results were closer to reality and exhibited slightly higher values of energy recovery. A novel “techno-ecological” metric, computed as the ratio of energy recovery to avoided amounts of GHG emissions, was suggested for controlling landfill transformation. Accordingly, transitioning from uncontrolled landfilling to energy recovery could reduce GHG emissions by up to 99.87%, with a generated power of 0.89 W per ton of CO₂-eq avoided by 2025.

The limited energy efficiency of sonochemical processes and the high reagent consumption of Fenton-based treatments remain the major challenges for large-scale water treatment. This study investigates a hybrid Sono–Galvano–Fenton (US/GF) process for the degradation of malachite green as a model organic pollutant, using parallel and series coupling configurations for the assessment of the potential synergistic effects of ultrasound and galvanic Fenton reactions. The results show that acoustic streaming can effectively replace mechanical stirring, providing comparable mixing performance while reducing mechanical energy requirements by approximately 20–30%. In addition, in situ sonochemical hydrogen peroxide generation contributes to pollutant degradation, achieving up to 35–50% removal efficiency, although this remains lower than the efficiency obtained with conventional Galvano–Fenton processes, which typically achieve removal efficiencies of 70–90%. In addition, continuous-flow hybrid configurations appear promising to improve in situ reagent production and overall process efficiency.