Novel nano-fertilizers derived from drinking water industry waste for sustained release of macronutrients: performance, kinetics and sorption mechanisms

Abstract Nanotechnology has emerged as a promising approach for the controlled release of nutrients, particularly phosphorus and potassium. These essential plant nutrients are often applied in excess, leading to environmental pollution and loss of efficiency in crop production. Innovative economic and highly efficient fertilizers are urgently needed to achieve the targeted crop production worldwide in the presence of limited land and water resources. Therefore, in this study, novel, eco-friendly, cost-effective and enhanced efficiency nano-enabled fertilizers, NEF (nWTF1and nWTF2) were synthesized by impregnation of nanostructured water treatment residuals (nWTR) with (KH2PO4 + MgO) at 1:1 and 3:1 (w/w) ratios respectively using a planetary ball mill. The nWTR, nWTF1 and nWTF2 were extensively characterized. The water retention behavior and the sustained release of nutrients from the fabricated nano-enabled fertilizers (nWTF1 and nWTF2) in distilled water and sandy soil were investigated and monitored over time. The water retention capacity of the soil treated with nWTF2 after 26 days was 9.3 times higher than that of soil treated with conventional fertilizer. In addition, the nWTF2 exhibited lower release rates of P, K and Mg nutrients for longer release periods in comparison with the conventional fertilizers. This is a significant advantage over traditional fertilizers, which release nutrients quickly and can lead to leaching and nutrient loss. The main interaction mechanisms of PO4–K–Mg ions with nWTR surface were suggested. The results of the kinetics study revealed that power function was the best suitable model to describe the kinetics of P, K and Mg release data from NEF in water and soil. The produced NEF were applied to Zea maize plants and compared to commercial chemical fertilizer control plants. The obtained results revealed that the nano-enabled fertilizers (nWTF1 and nWTF2) significantly promoted growth, and P content compared with the commercial chemical fertilizer treated plants. The present work demonstrated the power of nano enabled fertilizers as efficient and sustained release nano-fertilizers for sustainable agriculture and pollution free environment

Effect of Carbon Nano-Tubes, Micro and Nano Dispersions of SiC and Al2O3 on the Mechanical and Physical Properties of Pure Copper

 Reviews on Advanced Materials Science 52(1):126-133 · December 2017This paper studies the physical and mechanical properties of pure copper powder with various reinforcement materials at different volume fractions. The used reinforcement materials are carbon nanotubes CNT (0.5-2 wt.%) as nano particles, Al2O3 (1-4 wt.%), and SiC (1-4 wt.%) as micro particles. Various characteristics were evaluated on the composite specimens such as microstructures, density, electrical conductivity, thermal conductivity, hardness, and compression properties to investigate the suitable reinforcement percentage that achieves the best physical and mechanical properties. The micron-sized Al2O3 and SiC and nano sized CNT has shown an enhancement on the mechanical and physical properties of the composite. The electrical and thermal conductivities were evaluated and the results have shown positive enhancements

Sludge

International audienceWater treatment residuals, sewage sludge and dredged sediments, hereinafter referred to as sludge, share common features, like inherent high moisture content, high organic and mineral pollutant load and above all a pasty consistency. Several recovery opportunities exist. However, sludge composition is closely correlated with human activity and the design of the recovery processes requires knowledge of physical, thermal or biological characteristics of the sludge that will be processed, often even before the specific sludge exists. Therefore, sludge characterization is a key challenge for the process design, control and optimization and further valorization. The present chapter is divided into four parts dedicated to the composition, the material properties, the dynamic processing properties and the environmental assessments, respectively. Standard tests methods for the characterization of solids and water distribution in sludge are introduced first. Then, the fate of organic constituents, inorganic nonmetallic and metallic constituents as well as pathogenic organism. In the second part, standard and state-of-the-art methods for the characterization of chemical, physical and thermal properties of sludge are described. Dynamic tests, required for the selection and design of conventional processes for sludge concentration and conveying, are detailed in the third part. Finally, methods for assessing the environment impacts of sludge and secondary raw materials derived from sludge are addressed