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Opuntia ficus-indica (Cactaceae) is an attractive renewable resource from arid and semi-arid regions of the world, including the north of Africa and Tunisia. It has suitable potential for use as a cellulose source for producing carboxymethyl cellulose (CMC). The chemical composition of fibers obtained from underground (roots) and aerial (trunk) parts of Opuntia ficus-indica, such as cellulose, holocellulose, lignin and ashes, was determined using normed and standardized methods. Individualized cellulose fibers were extracted from both raw materials using an eco-friendly delignification process based on soft treatment with sodium hydroxide/hydrogen peroxide mixtures followed by mechanical operation. The extracted cellulose fibers were carboxymethylated using sodium hydroxide and mono-chloroacetic acid, in the aqueous ethanolic medium. In this work, novel eco-friendly hydrogel films were synthesized based on high-quality carboxymethyl cellulose "CMC-R" from the roots ([DS] = 0.64) and "CMC-T" from the trunk ([DS] = 0.97) cross-linked with citric acid. The produced hydrogel films from both CMCs have various morphological structures, acceptable mechanical properties, and improved barrier behaviors. However, CMC hydrogel films from Opuntia ficus-indica are totally biodegradable within 20 days and became good candidates to replace synthetic polymers in packaging films. [ABSTRACT FROM AUTHOR]

CPG's wastewater from phosphate ore processing was characterized and its phytotoxicity before and after physicochemical treatment inside washing units was investigated for the first time. Mineralogical, spectral, physicochemical and microbiological characterizations showed that these wastewaters are relatively alkaline due to the high calcium and phosphorus contents. In fact, numerous minerals mainly fluorapatite, clinoptilolite and gypse were identified. In addition to its high salinity (EC = 9890 µS cm−1), the BOD5/COD ratio is equal to 0.949, which allows for the estimation that this effluent is potentially biodegradable. The microbiological characterization revealed the presence of revivable aerobic bacteria as; total coliforms (TC), fecal coliforms (FC), Pseudomonas, anaerobic sulfite bacteria (ASR), and fungi (F), whereas a complete absence of Salmonella, Vibrio cholera (CV), and Helminth egg (HE) was noted. In the second part, the influence of varying concentrations of phosphate wastewater was studied on radish, lentil, wheat and fenugreek seeds. Phosphate effluents were provided at 10%, 25%, 50%, 75% and 100%. Results were compared with a control group of the same seeds, irrigated with tap water. Based on several germination tests, plant irrigated with treated or untreated effluent exhibited a prominent reduction in growth traits at all four harvests. Except plant treated with treated effluent at 25% which generally induced no significant phytotoxicity to all species and which can play a fertilizer role. The adverse effects occurred with effluent-dose dependent manner. The high toxicity of untreated effluent compared to the treated effluent was inferred from the results. Nevertheless, the treated ffluent is still toxic, except at very low concentrations acting as a fertilizer. [ABSTRACT FROM AUTHOR]

Echinops spinosissimus Turra subsp. roots was investigated, after extraction with two different solvents: ethanol and ethyl acetate, for its phenolic profile as well as biological activities. Echinops spinosissimus Turra subsp. spinosus roots ethanolic extract was characterized by the highest content of total polyphenols (19.3 mg GAE/100 g of DW). In addition, the phenolic profiles of the two studied extracts were analysed using HPLC-UV, where p-coumaric (8.59 mg/kg of DW) and cinnamic acids (4.68 mg/kg of DW) were detected as the most abundant phenolic acids, and kaempferol was the predominant flavonoids (30.37 mg/kg of DM) followed by quercetin and rutin in the ethanolic extract. While, only p-coumaric acid, epicatechin, kaempferol and quercetin were identified and quantified in ethyl acetate roots extract. All tested extracts exhibited an antimicrobial effect against Gram-positive and Gram-negative bacteria. These findings indicate that Echinops spinosissimus Turra subsp. spinosus roots can be regarded as a new source of edible oil having health benefits and nutritional properties. [ABSTRACT FROM AUTHOR]

Stipagrostis pungens is a traditional medicinal annual plant growing in Tunisia. It is quite a small plant suitable for Tunisia arid areas. This paper deals with the study of the chemical composition and the cooking of this raw material, in order to produce lignocellulosic fibres. The chemical composition of S. pungens has showed that it contains quite high amount of extractives, lignin (around 12%) and polysaccharides (71%). The α-cellulose amounts are acceptable (44%). Finally, the ash content was around 4.65%. With the insight of such data, we have undertaken the soda-anthraquinone cooking of S. pungens and produced lignocellulosic fibres. Different cooking temperatures (120 and 140°C) and times were tested. A yield of about 43% w/w was obtained and the produced pulps had a kappa number of around 11. Finally, the isolated fibres were used to produce laboratory handmade standard sheets. The structural and mechanical properties of the prepared samples were close to those of other common annual plants-based fibre-mats. [ABSTRACT FROM AUTHOR]

Four plants species namely Astragalus armatus , Retama raetam , Pituranthos chloranthus and Nitraria retusa were collected from Kasserine (Tunisia) to study their suitability for pulp and papermaking. Their chemical composition revealed that the α-cellulose content in R. raetam was lower than the normal range of hardwood, but the others were acceptable for pulp production. The Klason lignin content in these species was lower than 20%, except for N. retusa (26%). The amount of extractives in organic solvents was quite high (close to 10%) in R. reatam and P. chloranthus . The previous raw materials were pulped by using the soda-anthraquinone cooking process, the morphological properties, kappa number and the degree of polymerisation of the pulps obtained were determined. Finally, laboratory handmade standard sheets were prepared from the unrefined pulps of P. chloranthus and A. armatus . Their characterisation showed that the prepared papers present low density values and quite good mechanical properties particularly for the unbleached pulp. This study demonstrates the high potentiality of these two species for papermaking applications. [ABSTRACT FROM AUTHOR]