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The removal of heavy metals from wastewater has become the subject of considerable interest at present. Thus, the use of novel adsorbents that are highly efficient is of critical importance for the removal of Cr (VI) ions from aqueous media. The adsorption of Cr (VI) ions from aqueous solutions by a new adsorbent, cedar wood sawdust, and the optimization of its adsorption parameters, were investigated in this study. Cedar wood sawdust was used in its native and HNO3/NaOH chemically modified forms as new low-cost sorbents to remove Cr (VI) ions from aqueous solutions in a batch system. The adsorption conditions were analyzed via response surface methodology. The RSM results showed that the optimal adsorption conditions yielding the best response were an adsorbent mass of 2 g for native Cedar and 1.125 g for its activated form, a metal concentration of 150 mg/L for native Cedar and 250 mg/L for activated, a temperature of 50 °C, a pH of 1, and a contact time of 67.5 min. At optimum adsorption conditions, the maximum adsorption capacities and the adsorption yields were 23.64 mg/g and 84% for native Cedar and 48.31 mg/g and 99% for activated Cedar, respectively. [ABSTRACT FROM AUTHOR]

Three Moroccan clays, denoted A1, A3 and A5, were sampled from the Fez region with the aim of potential use as aluminosilicate precursors for geopolymer synthesis. Each clay was subjected to calcination at 700 °C and analyzed using DTA/TG, grain size distribution measurements, XRD, and FTIR spectroscopy before and after heat treatment. The results showed that the three clays contain kaolinite in different proportions in addition to some associated minerals, such as quartz, hematite, calcite and dolomite. Heat treatment successfully activated the clay by the amorphization of kaolinite, which is essential for geopolymerization. Some other changes were observed in the associated minerals, especially carbonates, which partially or totally decomposed depending on the clay, while other minerals remained intact. The SBET and NBO values are in accordance with the degree of polymerization, and the obtention of consolidated materials is possible by alkali activation of the calcined clays.

The disposal of vegetable wastes in nature is harmful for marine habitats and biota. These types of waste are frequently used as fuel, generating polluting products, with undesired side effects on the environment. Therefore, it is essential to find better alternatives for the capitalisation of these waste products. Their diversified chemical composition can become a potential resource of high added value raw materials. The knowledge of the physicochemical properties of these wastes is therefore essential. The present work aimed for characterising the physicochemical properties of a plant residue belonging to the Asteraceae Family, collected from a vegetable market in Fez city, Morocco. The vegetal tissues were analysed by Scanning Electron Microscopy coupled with EDX, X-ray Diffraction, Fourier Transform Infrared Spectroscopy, Inductively Coupled Plasma Atomic Emission Spectroscopy, and by Thermogravimetric/Differential thermal analyses. Other additional parameters were also measured, such as moisture, volatile matter, ash, and fixed carbon contents. Acidic and basic surface functions were evaluated by Boehm's method, and pH points at zero charge were equally calculated. The results revealed a strong congruence between the morphological and structural properties of this plant. These vegetal wastes comprise a homogeneous fibrous and porous aspect both in surface and in profile, with a crystalline structure characteristic of cellulose I. A mass loss of 86.49% for leaves and 87.91% for stems in the temperature range of 100 °C to 700 °C, and pHpzc of 8.39 for leaves and 7.35 for stems were found. This study clarifies the similarities and differences between the chemical composition and morphological structure of these vegetal wastes, paving the way for future value-added applications in appropriate fields. [ABSTRACT FROM AUTHOR]

• Industrial wood wastes cause oxidative stress in aquatic organisms. • The fish exposed to wood wastes have lethargic movements. • SOD, CAT and GTx activities increased significantly in fish exposed to sawdusts. • The excessive generation of reactive oxygen causes the membrane lipid lesions. The aquatic pollution due to sawmill wood wastes constitutes a major threat to hydro-chemical and fauna characteristics of the aquatic ecosystems. When this kind of organics wastes enter aquatic environment it can be taken up by aquatic organisms through respiration and/or through their diet. This could concurrently result in oxidative stress and later having adverse effect on physiological and biochemical function. The importance of fish in the society cannot be over emphasized, hence there is the need to know the influence of sawmill wood wastes on the water quality and fish. Therefore, this work aims to study the impact of five species of wood wastes on a type of fish named common carp (Cyprinus carpio) known as the most widely cultured fish species in the world and on its aquatic environment. The monitoring of water parameters showed deterioration in water quality. The activities of superoxide dismutase (SOD), Catalase (CAT), glutathione peroxidase (GPx) and lipid peroxidation (MDA) were investigated to evaluate the degree of oxidative stress. According to t-student, there was a significant difference compared to control (P < 0.05) in the level of SOD, CAT, GPx and MDA activities in fish exposed to 5 g·l−1 of each sawdust except for GPx, a non-significant difference (p > 0.05) was noted in the case of Beech and Dibetou. When the dispersed amount was about 0.375 g·l−1 we noted a significant difference in the level of SOD and GPx, except for GPx a non-significant difference was detected in the case of Cedar. The level of CAT was significantly difference just in the case of Cedar and Dibetou and that of MDA was significantly difference just in the case of Beech and Mahogany. We conclude therefore that sawmill wood waste not only impact the water quality adversely but also alters the levels of different enzymes activities in Cyprinus Carpio fish by the inhibition of SOD, CAT and GPx activities and by the production of MDA, which reflects response to oxidative stress. This study provides a rational use of these enzymes as suitable biomarkers with different degrees of specificity and as important tool for environmental monitoring. [ABSTRACT FROM AUTHOR]