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Full-Scale Applications of Constructed Wetlands in Africa
Published in María del Carmen Durán-Domínguez-de-Bazúa, Amado Enrique Navarro-Frómeta, Josep M. Bayona, Artificial or Constructed Wetlands, 2018
A particularly interesting and robust technology for warmer climates are upflow anaerobic sludge blanket reactors (UASB) which can convert organic load into biogas. The effluent however needs further treatment before discharge or reuse, hence the use of constructed wetlands as post-treatment technology, as studied by Morsy et al. (2007) and El Khateeb et al. (2009). Both studied the same system located in Cairo, fed by municipal wastewater, and consisting firstly of a 1.3 m3 UASB reactor operating at an HRT of 8 hours and in a temperature range of 19-38°C. The effluent of the UASB was then continuously fed to a 2.4 x 1 x 0.25 m free water surface constructed wetland planted with Typha latifolia, operated at a 13.8 cm d−1 hydraulic loading rate. Finally, a 2.4 x 1 x 0.4 m horizontal subsurface flow constructed wetland filled with sand (0 3-4 mm), planted with the same vegetation and operated at the same hydraulic loading rate, provided final treatment. The idea behind this particular wetland configuration was to optimize nitrogen removal via nitrification-denitrification and to ensure good solids retention via the fine texture media of the subsurface flow system.
Facile auto-combustion synthesis of calcium aluminate nanoparticles for efficient removal of Ni(II) and As(III) ions from wastewater
Published in Environmental Technology, 2023
Hossam S. Jahin, Magdy I. Kandil, Mostafa Y. Nassar
The phase structure, crystallinity, and crystallite size of the as-prepared products were characterized by using an X-ray diffractometer (Bruker, model D8 Advance) with Cu/Kα radiation (λ = 1.5418˚A) (Metallurgical Development Research Centre, Cairo, Egypt). The surface morphology of the products was examined by using a field-emission scanning electron microscope (FE-SEM; model QUANTA-FEG-250) (National Research Centre, Cairo, Egypt). The microstructures of the products were studied by using a high-resolution transmission electron microscope (JEOL; model 2100 JEM) at an electron voltage of 80 kV (National Research Centre, Cairo, Egypt). The chemical compositions of the products were further examined on an FT-IR spectrometer (Thermo Scientific, model Nicolet iS10) in the frequency range of 400–4000 cm−1 (Chemistry Administration, Ministry of Trade and Industry, Cairo, Egypt). The thermal behaviour of as-prepared powder was investigated by using thermos-gravimetric analysis (TGA) (Shimadzu; model TA-60WS) at a heating rate of 10 °C/min under nitrogen gas atmosphere and the sample was heated from room temperature until 900 °C (Microanalytical Centre, Cairo University, Cairo, Egypt). The adsorption studies were carried out by using an inductively coupled plasma-optical emission spectrometer (ICP- OES; Optima 5300 DV, Perkin-Elmer, USA) (Central Laboratory for Environmental Quality Monitoring, National Water Research Centre, Elkantir, Egypt).