Water shortage is a very concerning issue in the Mediterranean region, menacing the viability of the agriculture sector and in some countries, population wellbeing. At the same time, liquid effluent volumes generated from agro-food industries in general and olive oil industry in particular, are quite huge. Thus, the main aim of this work is to suggest a sustainable solution for the management of olive mill wastewaters (OMWW) with possible reuse in irrigation. This work is a part of a series of papers valorizing all the outputs of a three-phase system of oil mills. It deals with recovery, by condensation, of water from both OMWW and OMWW-impregnated biomasses (sawdust and wood chips), during a convective drying operation (air velocity: 1 m/s and air temperature: 50 °C). The experimental results showed that the water yield recovery reaches about 95%. The condensate waters have low electrical conductivity and salinities but also acidic pH values and slightly high chemical oxygen demand (COD) values. However, they could be returned suitable for reuse in agriculture after additional low-cost treatment.

Since buildings are one of the major contributors to global warming, efforts should be intensified to make them more energy-efficient, particularly existing buildings. This research intends to analyze the energy savings from a suggested retrofitting program using energy simulation for typical existing residential buildings. For the assessment of the energy retrofitting program using computer simulation, the most commonly utilized residential building types were selected. The energy consumption of those selected residential buildings was assessed, and a baseline for evaluating energy retrofitting was established. Three levels of retrofitting programs were implemented. These levels were ordered by cost, with the first level being the least costly and the third level is the most expensive. The simulation models were created for two different types of buildings in three different climatic zones in Palestine. The findings suggest that water heating, space heating, space cooling, and electric lighting are the highest energy consumers in ordinary houses. Level one measures resulted in a 19–24 percent decrease in energy consumption due to reduced heating and cooling loads. The use of a combination of levels one and two resulted in a decrease of energy consumption for heating, cooling, and lighting by 50–57%. The use of the three levels resulted in a decrease of 71–80% in total energy usage for heating, cooling, lighting, water heating, and air conditioning.

Olive Mill Wastewater (OMWW) treatment is considered to be one of the main challenges that Mediterranean countries face. Although several procedures and technologies are mentioned in the literature, these techniques have several disadvantages or have been limited to laboratory pilot validation without posterior industrial projection. Recently, an advanced environmental friendly strategy for the recovery of OMWW was established involving the impregnation of OMWW on dry biomasses, drying of these impregnated samples, and finally green fuels and biochar production. This established strategy revealed that the drying step is crucial for the success of the entire recovery process. Hence, two impregnated samples were prepared through OMWW impregnation on sawdust (IS) and olive mill solid waste (ISW). The drying kinetics of OMWW and impregnated samples (IS and ISW) were examined in a convective dryer (air velocity range from 0.7–1.3 m/s and the temperature from 40–60 °C). The experimental results indicated that the drying of the impregnated samples occurred twice as fast as for the OMWW sample. Such behavior was attributed to the remaining thin layer of oil on the OMWW surface Furthermore, the Henderson and Pabis model showed the suitable fit of the drying curves with a determination coefficient R² above 0.97. The drying rates were extracted from the mathematical models and the drying process was analyzed. The coefficient of effective diffusivity varied between 2.8 and 11.7 × 10⁻¹⁰ m²/s. In addition, the activation energy values ranged between 28.7 and 44.9 kJ/mol. These values were in the same range as those obtained during the drying of other agrifood byproducts. The final results could be very helpful to engineers aiming to improve and optimize the OMWW drying process.