China
Africa
Explore chapters and articles related to this topic
Membrane Systems
Published in Juan A. Asenjo, Separation Processes in Biotechnology, 2020
The use of dialysis to condition the broth during fermentation— dialysis fermentation—was pioneered by Gerhardt and co-workers (see Schultz and Gerhardt, 1969; Steiber et al., 1977). In dialysis fermentation, solutes are transferred between the culture and a reservoir across a membrane. The dialysis fermentation allows greater control of substrate concentrations. This control usually results in higher cell concentrations or higher cell productivity. Examples of these applications are presented by Steiber et al. (1977) for the production of ammonium lactate from lactose, and by Gallup and Gerhardt (1963) to increase the cell density of Serratia marcescens. Dialysis fermentation has also been used to remove growth-inhibiting products. The ethanol removal cited above is an example of this application, as is the removal of lactate from cultures of Lactobacillus delbrueckii (Friedmann and Gaden, 1970). More recently, Thompson used dialysis fermentation to control the substrate concentrations during growth of E. coli in order to study the physiological parameters of growth under those conditions.
Graphene-Inorganic Hybrids (I)
Published in Ling Bing Kong, Carbon Nanomaterials Based on Graphene Nanosheets, 2017
Ling Bing Kong, Freddy Boey, Yizhong Huang, Zhichuan Jason Xu, Kun Zhou, Sean Li, Wenxiu Que, Hui Huang, Tianshu Zhang
In summary, the sol–gel method has been employed to prepare various hybrids of TiO2 and graphene or graphene oxide. Various modifications have also been introduced to further increase the efficiency of the sol-gel method. For example, Chen et al. [42] used prepared rGO–TiO2 hybrids with different kinds of semiconductors, which could be controlled by adjusting the GO content in the starting solutions. Manga et al. [22] used an ionic salt, titanium (IV) bis(ammonium lactate) dihydroxide, as the precursor of TiO2, which had good water solubility and thus could be well mixed with GO solutions. It is expected that solution-based sol-gel method will be continuously popular in synthesizing TiO2–G hybrid materials.
Properties of the Elements and Inorganic Compounds
Published in W. M. Haynes, David R. Lide, Thomas J. Bruno, CRC Handbook of Chemistry and Physics, 2016
W. M. Haynes, David R. Lide, Thomas J. Bruno
Ammonium hydroxide Ammonium hypophosphite Ammonium iodate Ammonium iodide Ammonium iron(III) chromate Ammonium iron(III) oxalate trihydrate Ammonium iron(III) sulfate dodecahydrate Ammonium iron(II) sulfate hexahydrate Ammonium lactate Ammonium magnesium chloride hexahydrate Ammonium mercuric chloride dihydrate Ammonium metatungstate hexahydrate Ammonium metavanadate Ammonium molybdate(VI) tetrahydrate Ammonium molybdophosphate Ammonium nitrate Ammonium nitrite Ammonium nitroferricyanide Ammonium oleate Ammonium oxalate Ammonium oxalate monohydrate Ammonium palmitate Ammonium pentaborate tetrahydrate Ammonium pentachlororhodate(III) monohydrate Ammonium pentachlorozincate Ammonium perchlorate Ammonium permanganate Ammonium peroxydisulfate Ammonium perrhenate Ammonium phosphate trihydrate Ammonium phosphomolybdate monohydrate Ammonium phosphotungstate dihydrate Ammonium picrate Ammonium polysulfide Ammonium salicylate Ammonium selenate Ammonium selenite Ammonium stearate Ammonium sulfamate Ammonium sulfate Ammonium sulfide Ammonium sulfite Ammonium sulfite monohydrate Ammonium tartrate Ammonium tellurate Ammonium tetraborate tetrahydrate Ammonium tetrachloroaluminate Ammonium tetrachloropalladate(II) NH4OH
Synthesis of PbTiO3 nanoplates by two-step hydrothermal method with pH-adjusting agent of ammonia solution
Published in Journal of Asian Ceramic Societies, 2022
Guangyuan Yang, Zheming Li, Sanwen Peng, Jianglai Yue, Zhixiong Huang, Dongyun Guo
The reagents were of analytical-grade purity and were used without further purification in this study. PbTiO3 nanocrystals were synthesized from Pb(CH3COO)2 · 3H2O (Macklin 99%), bis(ammonium lactate) titanium dihydroxide (C6H18N2O8Ti, TALH, Macklin 50 wt%) by the two-step hydrothermal method, and ammonia solution was used as the pH-adjusting agent. The desired amounts of Pb(CH3COO)2 · 3H2O and TALH were dissolved in deionized water with stirring to form transparent Pb-Ti solutions. Then, ammonia solution was slowly added in the transparent Pb-Ti solutions to form the first-step precursors (30 ml) with continuous stirring. In the first-step precursors, the nominal ammonia concentration was 8.8 mol/L, and the nominal concentration of Pb-Ti feedstock varied from 0.025 to 0.1 mol/L. When the suspended gels were formed, they were centrifuged and washed with deionized water. Then, the precipitates were dispersed in the deionized water to form the suspended second-step precursors (30 ml) with different nominal ammonia concentrations (0–13.2 mol/L). The 30 ml second-step precursors were added to Teflon-lined autoclaves of 50 ml capacity, and they were sealed tightly. The autoclaves were heated at different synthesis temperatures (140–260°C) for different time (1–72 h), and then naturally cooled to room temperature with continuous stirring. The precipitates were centrifuged and washed with deionized water and ethanol in sequence.
Leachability and plant-availability of phosphorus in post-sorption wastewater filters fortified with biochar
Published in Environmental Technology, 2019
Ezekiel Kholoma, Gunno Renman, Wen Zhang, Agnieszka Renman
Batch experiments were carried out to determine the amount of extractable P in all filter materials. Distilled water (DW) and ammonium lactate (AL) solution were used as extractants. The AL solution consisted of 0.01 M ammonium lactate dissolved in 0.4 M acetic acid (CH3COOH) and adjusted to pH 3.7. It had been prepared and supplied by the laboratory staff of the Department of Soil and Environment, Swedish University of Agricultural Sciences, Uppsala, Sweden. Extraction with AL solution was performed according to the Swedish protocol SS 028310 which involves the use of organic acids (acetic and lactic acids) to simulate the action of organic acids excreted by plant roots and mineral acids [27–29]. Using the recommended solid-to-liquid ratio of 1:20 (w/v), 20 g of sample were added to 400 mL AL solution to prepare the mixtures which were then placed on an end-over-end shaker and rotated at 35 rpm for 1.5 h. The supernatant from the mixtures were transferred into centrifuge bottles and immediately centrifuged for 35 min. The extraction with DW involved the same procedure as with AL except for the shaking time which was 12 h as outlined in Wünscher et al. [30] experiment.
Application of diffusive gradients in thin-films technique for speciation, bioavailability, modeling and mapping of nutrients and contaminants in soils
Published in Critical Reviews in Environmental Science and Technology, 2022
Dong-Xing Guan, Si-Xue He, Gang Li, H. Henry Teng, Lena Q. Ma
For bioavailability measurement, different extractions have been used for different chemicals. For example, NaHCO3, ammonium oxalate, ammonium lactate, and CaCl2 solutions are used to extract bioavailable P (Nawara et al., 2017), whereas CaCl2, ethylenediaminetetraacetic acid, NaNO3, NH4NO3 and NH4Cl are used to extract bioavailable metals (Kumpiene et al., 2017). Similarly, DGT with different gels have been used to measure the bioavailability of different chemicals. Compared to traditional chemical extractions, DGT measurement provides a good estimate of metal uptake (e.g., Cd, Cu, Pb, Zn, and Ni) by plants. Davison et al. (1999) first investigated the relationship between DGT-measured metal concentrations in soils and those in plants. They found that plant uptake of Cd, Co, Cu, Ni, Pb and Zn by cress (Lepidium heterophyllum) does not simply depend on free ion activities in soil solution, but rather it is governed by diffusional transport of labile solution species augmented by its transfer from solid phase to solution in the rhizosphere, which can be captured by DGT measurements (Davison et al., 1999). For example, in a pot trial using 13 soils with different soil properties, plant uptake of Cd, Cu, Pb, and Zn by wheat (Triticum aestivum) was linearly related to DGT-measured metal concentrations. But metal uptake was generally more scattered or nonlinear with respect to free ion activity or CaCl2 extractable metal (Nolan et al., 2005). Other pot trials also showed that DGT is among the best soil tests for predicting metal uptake by plants (Table 2) (Dai et al., 2017; Han et al., 2019; Wu et al., 2018). However, at toxic concentrations, when metal uptake is controlled by plant self instead of soil supply, DGT may overestimate metal bioavailability to plants (Ciadamidaro et al., 2017; Neu et al., 2018).