Formulation and rheological evaluation of liposomes-loaded carbopol hydrogels based on thermal waters.

The aims of this study were to develop topical liposomal hydrogels based on thermal waters (TWs) acquired in the region of Biskra (Northeast Algeria) and also to investigate their rheological properties. Liposomes containing two highly mineralized thermal waters, Baraka (BTW) and Salhine (STW), were prepared by probe sonication using phosphatidylcholine (PC) and cholesterol (Chol), plain or mixed with phosphatidylglycerol (PG). Based on their lipid composition, obtained liposomes presented vesicle sizes of 60 nm, a low polydispersity index, and various negative zeta potentials. It was noted that with increasing counterions charge in TWs the zeta potential of liposomes decreased toward neutral values.Carbopol (1%, w/w) hydrogels prepared with BTW, STW, and also demineralized water (placebo hydrogel) showed a non-Newtonian behavior, pseudoplastic fluid adjusted to Carreau model. The composition of thermal waters influenced highly the rheological properties of Carbopol hydrogels. Liposomal hydrogels were prepared by dispersing liposomes in hydrogels formulated with the same encapsulated thermal water. Regardless of composition or lipid concentration of added liposomes, the viscosity and viscoelastic parameters of Carbopol hydrogels changed negligibly. Indeed, liposome composition and lipid concentration seemed to have no effect on the rheological properties of Carbopol hydrogel in the presence of an important charge of cations. Hence, hydrogels and liposomal hydrogels based on thermal waters had suitable rheological properties for topical application and delivery of minerals in the skin.

Refuse-derived fuel potential production for co-combustion in the cement industry in Algeria.

As in many developing countries, municipal solid waste (MSW) management is one of the most significant challenges facing urban communities in Algeria. The effective management of solid waste involves the application of various treatment methods, and technologies to ensure the protection of public health and the environment. This research work aimed to examine potential production and utilization of refuse-derived fuel (RDF) from MSW to be used as a substitute fuel in cement kilns in Algeria. After receiving the input waste, sieves were used to categorize MSW according to size. The waste fractions >80 mm were subjected to a drying process in an open-air area and had been turned periodically in order to increase the dry matter (DM). A cost study was performed to evaluate the environmental and economic savings of RDF utilization in the cement industry. At the end of the drying process, as a consequence of the waste moisture reduction, the low heating value was found to be 16 MJ kg-1, and the DM 87%. Concerning heavy metal content, their concentrations were within the limits set by the European Committee for Standardization (CEN)/TC 343 standardization. The chlorine content was around 0.37% to 0.80%. The feasibility study of adding RDF as a substitute fuel in the cement industry showed that when 15% of RDF is used, the RDF consumption will be 4.7 metric tonnes (Mt) h-1, which will save 4347.2 Nm3 h-1 of natural gas and 0.3 Mt h-1 in carbon dioxide emissions, with a net gas cost saving of 65 USD h-1.

The vermicomposting for agricultural valorization of sludge from Algerian wastewater treatment plant: impact on growth of snap bean Phaseolus vulgaris L.

In the present study, vermicomposting of sewage sludges and their application in agriculture have been investigated. The impact of Eisenia fetida earthworms on the stabilization of these sludges during 7, 14 and 21 days was assessed. The final product was applied as soil amendment (set-1) to evaluate the effects on vegetative parameters (Chlorophyll, carotenoid, number of nodules, leaf weight, and plant height) of Phaseolus vulgaris.L bean. In the second test (set-2), the amendment was made with raw sludge. In the third test (set-3), the worms were added to the raw sludge at the time of spreading and left during the whole period of beans growth. In order to identify and better understand the behavior and role of worms with regard to sludge, their growth (weight and length), some pathogens and physico-chemical parameters were assessed during the vermicomposting. Results showed significant increase of earthworm weight of 10.62, 23.89 and 35.72 % after 7, 14 and 21 days of sludge vermicomposting, respectively, which explain their acclimatization. The vermicomposting caused a decrease of feacal coliforms number and organic matter (OM), an increase in electrical conductivity (EC) and stabilization in pH. Furthermore, significant differences were obtained for all plants vegetative parameters in soil amended with vermicomposts, compared to the control (unamended soil). Indeed, a significant increase of the chlorophyll level (a, b) was noted in the beans having undergone sludge spreading. However, worm-stabilized sludge for 7 days (set-1) showed the highest chlorophyll a and b levels about 16.1 and 24.64 µg/g, respectively, against 10.13 and 4.38 µg/g in the control. For the carotenoid, a significant decrease was observed compared to the control. Our experiments have also showed that the application of vermicomposted sludge significantly increases the number of nodules, leaf weight and plant height of Phaseolus Vulgaris L. snap beans.