The pollution of freshwater resources with crude petroleum oil is a major environmental issue in oil-producing countries. As a result, the remediation of polluted aquatic ecosystems using eco-friendly and cost-effective technology is receiving increased global attention. In this study, the ability of Azolla pinnata R. Br. to remediate petroleum-polluted freshwater was assessed. The remediation potentiality was determined by evaluating the total petroleum hydrocarbon degradation percentage (TPH%) and changes in the molecular type composition of saturated and aromatic hydrocarbon fractions. TPH% was estimated gravimetrically, and changes in the molecular type composition of saturated and aromatic fractions were measured using gas chromatography and high-performance liquid chromatography, respectively. The results reveal that A. pinnata has the potential to phytoremediate freshwater polluted with low levels (up to 0.5 g/L) of petroleum hydrocarbons (PHs). After seven days of phytoremediation, the degradation rate of total PHs was 92% in the planted treatment compared with 38% in the unplanted positive control. The highest breakdown of PHs for the normal paraffinic saturated hydrocarbon fraction occurred in the presence of A. pinnata combined with Anabena azollaea (A-A), which showed a moderate degradation capacity toward total aromatic hydrocarbons (TAHs) and total polycyclic aromatic hydrocarbons (PAHs). The results indicate that A. pinnata effectively removed C18, a saturated PH, and acenaphthene (Ace), an aromatic PH. Therefore, this study suggests that A. pinnata is a useful tool for the remediation of freshwaters contaminated with low pollution levels of crude oil.

In oil-producing countries, water pollution by crude petroleum oil frequently occurs and causes many environmental problems. This study aims to investigate the effect of crude petroleum oil on the growth and functional trails of the economically important freshwater plant Azolla pinnata R. Br. and to report on the plant’s resistance to this abiotic stress. Plants were raised in an open greenhouse experiment under different levels of crude oil pollution ranging from 0.5 to 2.0 g/L. Plant functional traits were monitored over a three-week period. Plant cover of A. pinnata was decreased with the increased levels of oil pollution. The total chlorophyll content decreased from 0.76 mg/g fresh weight under 2 g/L oil treatment after 21 days of growth. The chlorophyll a/b ratio exceeded the unity at crude oil treatments above 1 g/L, with values reaching 2.78 after seven days, while after 21 days, the ratio ranged from 1.14 to 1.31. The carotenoid content ranged from 0.17 mg/g in the control to 0.11 mg/g in the 2 g/L oil treatment. The carotenoid content varied over time in relation to DNA% damage, which increased from 3.63% in the control to 11.36% in the highest oil treatment level of 2 g/L. The crude oil stress caused severe damage in the frond tissues and chloroplast structure of A. pinnata, including a less compacted palisade, the malformation of the epidermis, the disintegration of parenchyma tissue, and the lysis and malformation of the chloroplasts. Since A. pinnata cannot withstand high concentrations of crude oil pollution, it is for use in the remediation of slightly polluted freshwaters up to 0.5 g/L.

The Mediterranean region, distinguished by its cultural heritage and industrialization, suffers from significant pollution levels of polycyclic aromatic hydrocarbons (PAHs) due to frequent petroleum-related activities such as petroleum extraction and consumption. Being dominant pollutants, PAHs cause significant deterioration of historic buildings and materials. This review comprehensively explores PAH-induced heritage deterioration, especially PAH-induced microbial deterioration, and explores current solutions and future perspectives for cultural heritage preservation.

Ebenus armitagei Schweinf. et Taub is a near-endemic species in Egypt and Libya. The IUCN has listed E. armitagei as endangered since 1997. Global warming may harm the plant’s environment, increasing its extinction risk. This study examines the leaf anatomical adaptations to different climatic parameters over the past 80 years. At Ras El-Hekma, Egypt, we collected leaves from herbarium specimens in 1954, 1964, and 2006 and filed samples in 2024 to study descriptive and quantitative traits. Leaf shapes, mesophyll tissue, and central vascular bundles were described. Quantitative traits included leaf blade thickness, cross-sectional areas of adaxial and abaxial idioblasts, vascular xylem, phloem, sclerenchyma, xylem diameters, and their hydraulic conductance. All descriptive traits remained constant over time, indicating their fundamental role in plant adaptation to arid deserts. In contrast, all quantitative traits increased from 1954 to 2006 and decreased towards 2024, illustrating significant retardation in plant survival mechanisms recently. The quantitative traits exhibited strong negative responses to rainfall change patterns. In addition, the adaxial idioblast area showed two more negative relationships with air and soil temperatures. Rainfall was a primary climate driver for quantitative traits over the studied years, along with air and soil temperatures for the adaxial idioblast area.