Impact of Treated Wastewater Reuse on Agriculture and Aquifer Recharge in a Coastal Area: Korba Case Study

Treated wastewater (TWW) reuse has increasingly been integrated in the planning and development of water resources in Tunisia. The present study aimed the evaluation of the environmental and health impact that would have the reuse of TWW for crops direct irrigation or for the recharge of the local aquifer in Korba (Tunisia). For this purpose water analyses were carried on the TWW intended for the aquifer recharge and on underground water of this area. As for underground water before recharge, no contamination by organic matter or heavy metals is shown but high salinity, nitrate, potassium and chloride concentrations are detected. The bacteriological analyses show the occurrence of faecal streptococcus, thermo-tolerant coliforms, total coliforms and E coli, but absence of salmonella. These results indicate that this water is not suitable for irrigation worse still for drinking purpose. The monitoring of TWW pollutants has demonstrated that oxygen demands (COD and BOD) do not exceed the Tunisian standards for TWW used in agriculture (NT 106.03) except for August when samples reach high values (COD = 139 mg O₂ L^− 1, BOD = 34). It is also the case for temperature, electrical conductivity (EC), salinity and pH. Heavy metal concentrations are under the detection limit. The determination of nutrients shows relatively low concentrations of nitrates, nitrites and orthophosphate (the maxima in mg L^− 1 are respectively 6.6, 5.6 and 0.92) whereas the potassium levels are high (up to 48.8 mg L^− 1) and the ammonia levels very high, reaching 60.6 mg L^− 1. As for bacteriological pollution, while no salmonella and intestinal nematods are detected, high concentrations of total coliforms, thermo-tolerant coliforms, faecal streptococci and E. coli are analysed. Consequently, the better use of TWW in this region would be the use of infiltration basins for the recharge of the deteriorated aquifer by TWW. It would give the opportunity to better the quality of the TWW reaching the groundwater by an additional treatment for bacteriological and suspended solid (TSS) contaminants while being an alternative water for the aquifer recharge and a coastal barrier against seawater intrusion.     

Molecular Regulation of Canalicular ABC Transporters

The ATP-binding cassette (ABC) transporters expressed at the canalicular membrane of hepatocytes mediate the secretion of several compounds into the bile canaliculi and therefore play a key role in bile secretion. Among these transporters, ABCB11 secretes bile acids, ABCB4 translocates phosphatidylcholine and ABCG5/G8 is responsible for cholesterol secretion, while ABCB1 and ABCC2 transport a variety of drugs and other compounds. The dysfunction of these transporters leads to severe, rare, evolutionary biliary diseases. The development of new therapies for patients with these diseases requires a deep understanding of the biology of these transporters. In this review, we report the current knowledge regarding the regulation of canalicular ABC transporters’ folding, trafficking, membrane stability and function, and we highlight the role of molecular partners in these regulating mechanisms.     

Biosourced vanillin Schiff base platform monomers as substitutes for DGEBA in thermoset epoxy

Diglycidyl ether Schiff base monomers were prepared from vanillin and various diamines. FT-IR, ¹H NMR, ¹³C NMR, and mass spectroscopy were used to determine their structure. Cured thermoset epoxies made with them were compared to commercial epoxy in terms of mechanical properties. Tensile strengths ranged from 35.1 to 60.4 MPa, Young's modulus from 3.9 to 6.9 GPa, similar to the commercial product. The glass transition ranged from 80 to 117°C, the phase transition T_α from 80 to 121°C and the storage modulus from 2 to 3.5 GPa. Thermogravimetric analysis showed that the vanillin-based epoxies were less heat resistant but had higher residual mass (20-30% wt/wt). Hydrolysis, hydrophobicity and degradation were also monitored to evaluate their potential for coating applications.     

Synthesis and Some Surface Properties of Glycine-Based Surfactants

A new group of anionic surfactants, namely sodium salts of secondary alkanesulfonamidoacetic acid, were synthesized using n-alkanesulfonyl chlorides as starting materials. These surfactants, having the formula: R–SO₂–NH–CH₂–COONa, with R = C₁₂, C₁₄, C₁₆ and C₁₈, were obtained in a simple way with quantitative yields. Different chain lengths and positional isomers of this new type of surfactants are expected to present differences in surface properties and foamability. The surface properties including critical micelle concentrations and minimal surface tensions γ_min were determined for each prepared surfactant using surface tension measurements with a Wilhelmy plate. Surface excess and minimum area per molecule at the air–water interface were determined for different concentrations at 25 and 50 °C using the Gibbs equation. The foaming power was also determined by the Bartsch method, and the results obtained were compared to those of a commercial surfactant, the linear alkylbenzenesulfonate. The stability of the foam formed was also evaluated. As expected, these surfactants exhibit good surface properties and show good foaming power.     

Design of Nanostructured Waterborne Adhesives with Improved Shear Resistance

The mechanical and adhesive properties of a series of model nanostructured waterborne PSA films have been characterized. The base polymer composition of the latex has been kept constant but systematic modifications have been carried out: the introduction of nanoparticles localized at the interfaces between particles, and the incorporation of a crosslinking agent. The mechanical properties have been characterized and show that the most effective modifications result in an increase in the low‐frequency modulus in the small‐strain regime and in a more pronounced softening and strain‐rate‐dependent behavior in the large‐strain regime. In industrial standard tests, this combination gives a dramatically increased resistance to shear while maintaining a high value of peel resistance.

     

Modulation of the superoxide anion production and MMP-9 expression in PMA stimulated THP-1 cells by olive oil minor components: Tyrosol and hydroxytyrosol

Extra virgin olive oil has been associated with a reduced incidence of risk factors for coronary heart disease also owing to the presence of antioxidant biophenols. Reactive oxygen species (ROS) and matrix metalloproteinase-9 (MMP-9) have been implicated in numerous somatic illnesses, including cardiovascular disorders and cancer. The aim of this work was to study the capacity of virgin olive oil tyrosol (T) and hydroxytyrosol (HT) at impairing superoxide production and MMP-9 expressions in monocyte cells (THP-1) conveniently differentiated into adherent macrophages, taken as a model of human macrophages implicated in atheroma.O₂⁻ production was evaluated in THP-1 cells by using lucigenin as a specific chemiluminescent probe. Cells, after differentiation for 72 h, were preincubated in the presence of HT and T at increasing concentrations for 4, 15 and 24 h, and then, monocyte-like cells were stimulated by phorbol myristate acetate (PMA) and the O₂⁻-dependent luminescence was immediately recorded at 37 °C by means of a Luminometer. Enzymatic activity of MMP-9 derived from a medium of cells preincubated, or not, with T or HT was tested by zymography.As compared to the cells without treatment, cells preincubated with HT, showed a decrease of O₂⁻ production (50%) at 1 ??M for 15 h of preincubation time. Tyrosol fully prevented ROS overproduction at 15 h and, like HT displayed a high degree of protection but at higher concentrations and later time points (24 h). Gelatin zymograms revealed a reduction of the expression of MMP-9 in conditioned medium derived from T and HT-treated cells. These findings give further evidence in favour of olive oil consumption to counteract cardiovascular diseases.     

Mucoadhesive Polymeric Hydrogels for Nasal Delivery of Acyclovir

The study evaluated different mucoadhesive polymeric hydrogels for nasal delivery of acyclovir. Gels containing poly-N-vinyl-2-pyrrolidone (PVP) were prepared with crosslinking achieved by irradiation with a radiation dose of 15 kGy being as efficient as 20 kGy. Gels containing chitosan and carbopol were also evaluated. The mucoadhesive properties of gels were measured by a modification of a classical tensile experiment, employing a tensile tester and using freshly excised sheep nasal mucosa. Considering the mucoadhesive force, chitosan gel and gel prepared with 3% PVP in presence of polyethylene glycol (PEG) 600 were the most efficient. The in vitro drug release depended on the gel composition. Higher release rates were obtained from PVP gels compared to chitosan or carbopol gels. The release rate of drug from PVP gels was increased further in presence of PEG or glycerol. Histopathological investigations proved that the PVP was a safe hydrogel to be used for mucosal delivery. The PEG in gel formulations caused less damages to the nasal mucosal compared to formulation containing glycerol.