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This study aims to prepare activated carbon from an interesting biomaterial, corresponding to the cores of Ziziphus lotus, for the first time to the best of our knowledge, according to a manufacturing process based on its chemical and thermal activation. These cores were chemically activated by sulfuric acid for 24 h and then carbonized at 500°C for 2 hours. The obtained activated carbon was characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and Brunauer–Emmett–Teller (BET) analysis. The adsorption of methylene blue (MB) on the activated carbon was evaluated, by Langmuir and Freundlich models examination, in order to explain the adsorption efficiency in a systematic and scientific way. Moreover, pseudo-first-order and pseudo-second-order kinetic models were used to identify the mechanisms of this adsorption process. The characterization results showed an important porosity (pore sizes ranging from 10 to 45 µm), a surface structure having acid groups and carboxylic functions, and a specific surface of 749.6 m2/g. Results of the MB adsorption showed that this process is very fast as more than 80% of MB is adsorbed during the first 20 minutes. In addition, increasing the contact time and temperature improves the MB removal process efficiency. Moreover, this adsorption’s kinetic modeling follows the pseudo-second-order model. Furthermore, data on the adsorption isotherm showed a maximum adsorption capacity of 14.493 mg/g and fit better with the Langmuir model. The thermodynamic parameters (∆G0, ∆S0, and ∆H0) indicate that the adsorption process is endothermic and spontaneous. Therefore, Ziziphus lotus can be used as a low-cost available material to prepare a high-quality activated carbon having a promising potential in the wastewater treatment.

Background. The hospital environment, especially surfaces and medical devices, is a source of contamination for patients. Objective. This study carried out, to the best of our knowledge, for the first time at Taza Hospital in Morocco aimed to assess the microbiological quality of surfaces and medical devices in surgical departments and to evaluate the disinfection procedure in time and space. Methods. Samples were taken by swabbing after cleaning the hospital surface or medical device, to isolate and identify germs which were inoculated on semiselective culture media then identified by standard biochemical and physiological tests, using the analytical profile index (API) galleries. Moreover, the association rules extraction model between sites on the one hand and germs on the other hand was used for sampling. Results. The study showed that 83% of the samples have been contaminated after biocleaning. The most contaminated services have been men’s and women’s surgeries. 62% of isolated germs have been identified as Gram-positive bacteria, 29% as Gram-negative bacteria, and 9% as fungi. Concerning the association rules extraction model, a strong association between some contaminated sites and the presence of germ has been found, such as the association between wall and nightstand and door cuff, meaning that the wall and nightstand contamination is systematically linked to that of the door cuff. The disinfection procedure efficacy evaluation has enabled suggesting renewing it each 4 h. Conclusion. Microbiological monitoring of surfaces is necessary at hospital level through the use of the association rule extraction model, which is very important to optimize the sampling, cleaning, and disinfection site scenarios of the most contaminated ones.

Taza City is among the Moroccan cities which is in full urban expansion, with a daily wastewater discharge volume estimated at 16534 m3/d in 2020, and expected to reach 20056 m3/d by 2030. These waters, collected in a combined sewerage network, are directly released into the natural environment without any treatment. Indeed, a large part of this water is discharged into Oued Defali, the main tributary of Oued Larbâa. In order to manage and better understand these discharges impact on the streams crossing this city, wastewater sampling campaigns were carried out for one year from May 2018 to April 2019 at domestic (S1) and industrial (S2) sites. The wastewater physicochemical characterization revealed that these discharges are highly loaded with organic matter in terms of chemical oxygen demand (S1 avg = 1231.44 mg/l and S2 avg = 933.03 mg/l), biochemical oxygen demand (S1 avg = 511.87 mg/l and S2 avg = 464.35 mg/l), and suspended matter (S1 avg = 744.11 mg/l and S2 avg = 578.13 mg/l). The use of principal component analysis (PCA) has allowed us to collect as much information as possible from the database of the physicochemical analyses performed for the studied parameters.