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Salt-tolerant superabsorbent polymer (SAP) was synthesized to improve the water retention properties of saline-alkali soil. The Lop Nur saline-alkali soil of Xinjiang with high salinity (total dissolved salt: 18.13wt%) was the object of improvement. The good swelling capacity of SAP (69.04 g/g) under high salinity condition contributed to the superb slow-release water property and further [showed](https://www.wordhippo.com/what-is/another-word-for/build.html) [excellent](https://www.wordhippo.com/what-is/another-word-for/excellent.html) water retention property of SAP-saline-alkali soil (28 days), which showed a good application potential of SAP in saline-alkali land. The swelling mechanism under high salt condition was also explored. Notably, owe to the complexation reaction between and three hydrophilic groups of SAP, the swelling capability of SAP tended to keep steady when the concentration of CaCl exceeded 0.55wt%. Interestingly, the distribution of the calcium salt in SAP was directly displayed by the maximum intensity projection of computed tomography.

The establishment of biological soil crusts is widely perceived as a main method to control ecological environment in arid and semi-arid regions. However, artificial biocrusts are insufficient to face with some stress from environment by using traditional established methods. Hence in this study, kaolin, a common clay mineral, was introduced as a stabilizer by mixing with Microcoleus steenstruppi of different mass ratios for inoculating onto sand to establish artificial biocrust. The results showed that the addition of kaolin exhibited a significantly positive effect on promoting biocrust formation, and accelerating the biocrust development. Moreover, the artificial biocrust from 1:500 (algae:kaolin) inoculant achieved the best performances with coverage of 98%, and thickness of 5.62 mm after 86 days of incubation. The highest contents of chlorophyll a, exopolysaccharides, and soluble protein were also observed in 1:500 mass ratio of algae:kaolin throughout the biocrust development process. As for the water retention performances, the results of contact angle, water drop penetration time (WDPT), and repellency index (RI) illustrated that biocrusts improve water utilization in kaolin-treated groups by delaying the time of water infiltration, especially in 1:500 group. After 86 days post inoculation, a series of common bacteria appeared in the biocrusts such as actinobacteria and acidobacteria and decomposed metabolites from cyanobacteria as energy source to supply their own life activities. This study gains new insights on clay minerals on biocrust development and puts forward a new approach for rapid artificial biocrust establishment to reverse desertification.

The purpose of this paper is to provide an overview of the Climate Change (CC) in the Central African Republic (CAR). Many researches on strategies to fight CC and reduce Green House Gas (GHGs) emissions have been conducted. However, implementation poses a serious problem at different levels including political, economic and socio-environmental. CC is seen as one of the greatest challenges of the 21st century. The CAR, like other countries of the world, has ratified the Kyoto Protocol on 1st January 2008, which aims to reduce the GHGs emissions responsible for CC. Almost all sectors (Energy, Agriculture, Forest, Health, Transport, Economy...) are affected by CC. GHGs are abundant in the Earth's atmosphere. In the absence of efficient meteorological equipment and stations to save accurate data, the CAR and even Africa in general is considered a "black hole" of climate information which must be used by the Intergovernmental Panel-evolution of Climate change (IPCC) to evaluate effects of CC on the continent. Despite its low level of GHGs emissions, the CAR reaffirms its adherence to the principle of collective responsibility. Pursuant to 1CP / 19 (Further advancing the Durban Platform) by these ambitious measures to meet this challenge. Thus, in the CAR, political, military and economic constraints are obstacles to the implementation of strategies to fight CC. Given its low level of development, 80% of rural population, forests and lands of the CAR are the most affected by CC; These impacts in all sectors are very difficult to assess due to the lack of reliable data, of its very weak economy and the multiple armed conflicts that do not make the collection and updating of data easy, almost half of the territory 14 prefectures on 16 have been occupied by armed groups.

The porous La(III)- montmorillonite hydrogel beads (La-MMT_hb) with stable structure were fabricated via hydrogen-bond and electrostatic interactions for arsenic removal from water. The structural characteristics of La-MMT_hb and its sorption performances for As(V) were evaluated. The results showed that porous La-MMT_hb were clearly observed by scanning electron microscopy, and the addition of lanthanum significantly increased the specific surface area. The maximum adsorption capacity of La-MMT_hb for As(V) was 58.75 mg/g, reached within 4 h, at the optimum pH of 4 with optimum La dosage of 1%. The mechanism of adsorption can be attributed to the electrostatic forces between La(III) and H2AsO4− at pH 4, ion exchange of O H groups on the surface of adsorbent with H2AsO4− and complex chelate formation as.-NH3-H2AsO4 and -La-O-As.

Due to regional shortage of freshwater, the use of saline/seawater for Cu-Mo sulfide ore flotation has received considerable attention. However, the effects of various salts, especially the cations present in seawater, onmolybdenite flotation and the mechanisms involved remain unclear due to the complexity of the solutions applied. In this work, the influence of some commoncations (i.e., Na+, K+, Ca²⁺ and Mg²⁺) with sulfate(SO4²⁻) anions on molybdenite flotability was investigated in the absence of flotation reagents (i.e., frothers and collectors) at pH 10. Flotation results indicated a greater depression of molybdenite recovery with increased sulfate salt concentration. The underlying mechanisms responsible for the deleterious effects in the presence of Na+ and K+ can be attributed to the increased repulsive forces between molybdenite particles and bubbles owing to increased molybdenite oxidation to produce e.g., MoO4²⁻ and HMoO4⁻. However, the increased depression observed in the presence of Mg²⁺ and Ca²⁺ is likely due to the adsorption of precipitated Mg(OH)₂ and CaMoO₄, respectively, onto molybdenite surfaces. These clearly show the different depressing mechanisms due to monovalent and divalent sulfates on molybdenite flotation in the absence of flotation reagents, to reveal the influence of these sulfate salts on its natural flotability. Refereed/Peer-reviewed