From tissue to coagulant
Meftah and colleagues used the green outer part of the stem of Austrocylindropuntia subulata. Material was collected in the Settat region of Morocco. Cleaning, drying, grinding and sieving produced a powder from which an aqueous extract was prepared. The material's surface characteristics and ability to support coagulation and flocculation were studied. [Meftah et al. 2024]
Coagulation means destabilisation of fine suspended particles, while flocculation means their aggregation into larger clusters. These flocs can settle faster than dispersed particles. Plant material properties are related to macromolecules and functional groups that can interact with the surfaces of suspension components. The study analysed these properties using methods including infrared spectroscopy. [Meftah et al. 2024]
Experimental conditions and results
Trials concerned suspensions and wastewater rich in apatite material from the Khouribga region. Mixing tests were conducted in 1 l beakers. An initial rapid mixing phase was replaced by a slower phase, after which flocs were left to settle. The turbidity of liquid above the sediment and changes in the position of the sediment boundary were measured. Experiments were repeated three times. [Meftah et al. 2024]
The authors achieved a strong reduction in turbidity and accelerated settling compared with a sample without added coagulant. The effect varied with suspension concentration and extract dose. The results describe phase separation in a particular mineral system. A full assessment of treated water quality would additionally include dissolved components and microbiology. [Meftah et al. 2024]
Storage of powder and extract
Dry powder was stored for a year in a closed container in a dark place. It retained effectiveness in the tests after this time. The aqueous extract was also assessed after storage for six days and three months. Its ability to support sedimentation remained high, although the liquid changed colour and smell, which the authors linked to transformations of its organic components. [Meftah et al. 2024]
The difference between the stability of dry biomass and an aqueous preparation matters for process design. It provides information on the form in which raw material can be stored. Reproducibility between plant harvests, extraction parameters and behaviour in other wastewater require separate investigation. Using succulent tissue properties in controlled particle separation is biologically interesting. [Meftah et al. 2024]
Prepared from scientific publications. Accepted names were checked in POWO on 9 October 2026.
Extraction and optimization of Austrocylindropuntia subulata powder as a novel green coagulant
Meftah K., Meftah S., Lamkhanter H., Bouzid T., Rezzak Y., Touil S., Abid A., Extraction and optimization of Austrocylindropuntia subulata powder as a novel green coagulant, Desalination and Water Treatment, 2024, 318:100339, doi: 10.1016/j.dwt.2024.100339
Experiments on the use of powdered Austrocylindropuntia subulata chlorenchyma to coagulate and flocculate suspensions. They include material characterisation, sedimentation and turbidity removal tests, and the stability of dry powder and aqueous extract. The results concern specific mineral effluents and laboratory mixing conditions.
