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Soil Carbon Stock and River Carbon Fluxes in Humid Tropical Environments: The Nyong River Basin (South Cameroon)
Published in Eric J. Roose, Rattan Lal, Christian Feller, Bernard Barthès, Bobby A. Stewart, Soil Erosion and Carbon Dynamics, 2005
Jean-Loup Boeglin, Jean-Luc Probst, Jules-Rémy Ndam-Ngoupayou, Brunot Nyeck, Henri Etcheber, Jefferson Mortatti, Jean-Jacques Braun
Soils were sampled on Nsimi catchment, using profiles on summit and side slopes, and by auger in the valley. The organic C was analyzed in two ways: (1) wet oxidation method using potassium dichromate and titration with ammonium-iron sulfate (Anne’s method, Rouiller et al., in Bonneau and Souchier, 1994), performed at the Hydrological Research Center in Yaoundé (Cameroon), and (2) measurement of the CO2 volume evolved consecutively to the combustion of a soil aliquot, performed in the laboratories of the Centro de Energía Nuclear na Agricultura in Piracicaba (Brazil). The first method, appropriate for C contents > 1%, is not precise in the case of soils with low C content (C < 0.2%).
CuFe2O4@ hydroxyapatite composite for the environmental remediation of some heavy metal ions: Synthesis and characterization
Published in Water Science, 2021
Alaa A. Sery, Hanaa. A. El-Boraey, Salah A. Abo-Elenein, Reham M. ElKorashey
Stock solutions of 1000 ppm iron (II) and 1000 ppm aluminum (III) were prepared by dissolving the corresponding weights of Mohr’s Salt – ammonium iron sulfate (NH4)2Fe(SO4)2 · 6H2O and potassium aluminum sulfate dodecahydrate KAl(SO4)2 · 12H2O, respectively as sources of Al(III) and Fe(II) ions, in distilled water and using fresh dilutions for each experiment. The effect of the initial metal ion concentration on the removal percentage was investigated using a 1 g l−1 fixed adsorbent dose and stirring for 2 hours at a temperature of 25 oC. A 50 ml of metal-ion solutions with initial concentrations ranged between 10 and 250 mg l−1 were shacked at 135 rpm. The removal percentage was determined by measuring the metal-ion concentrations before and after treatment using Inductively Coupled Plasma (ICP), Optima 5300 DV-Perkin-Elmer. The removal percentage is calculated using Equation 1, as follows:
Synthesis and evaluation of a new polymeric scale inhibitor with multiple scale inhibition properties
Published in Journal of Dispersion Science and Technology, 2023
Xiping Ma, Zhaobo Zhou, Yandong Mu, Qinghong Huang
Then ESA, AA and PTA (molar ratio of ESA:AA:PTA was 1:1:0.5, total monomer concentration was 20 wt%) were dissolved in a triple flask and the catalyst ammonium iron sulfate (0.8 wt% of the monomer) and the initiator ammonium persulphate (10 wt% of the monomer) were slowly added dropwise and reacted at 95 °C for 3.5 hours to obtain the the final ter-polymer scale inhibitor P (ESA-AA-PTA). Finally, it was precipitated with ethanol, filtered, and the precipitate was washed 4–5 times with ethanol, and dried to obtain brown P(ESA-AA-PTA). The yield of P (ESA-AA-PTA) as 66.4% using Equation (1). And the synthesis process of P(ESA-PTA-AA) is shown in Figure 1.