The effects of oxygen supply rate and the presence or absence of nutrients on the kinetics of phenol degradation and oxygen consumption by a mixed microbial population were tested in a model system. The values for the maximum specific rate of phenol degradation (qSmax), the saturation constant (KS), and the inhibition concentration (SCR) were determined for unlimited growth (KLa = 340 h?1, growth medium) with 1.7 mmol g?1 h?1, 65 mg L?1, and 190 mg L?1. Under limitation conditions, alterations occur depending on the type of limitation. Nutrient limitations lead to values of 0.8 mmol g?1 h?1, 45 mg L?1, and 160 mg L?1, and oxygen limitations lead to 1.2 mmol g?1 h?1. 30 mg L?1, and 120 mg L?1, respectively. The results suggest that with excess oxygen, the rate of phenol degradation was higher and the inhibition effect of phenol was suppressed to some extent. Under the same high oxygen supply rate, the presence of nutrients in the model water significantly supported the phenol degradation rate. 相似文献
The adsorption of H+, OH– and ARS (Alizarin Red S) onto hydrous fluorapatite surfaces and Ca2+—ARS complexation in solution were studied by means of combined potentiometric and spectrophotometric titrations, as well as zeta potential and FT-IR measurements. Corresponding equilibrium constants of surface and solution reactions are determined. The application in flotation processes is discussed. 相似文献
This study investigated the adsorption and precipitation of phosphate by blast furnace slag (BFS) separately.
In order to evaluate the adsorption capacity of BFS, BFS was treated before its use by acid. The authors aim to develop a new porous carrier to adsorb simultaneously ammonium and phosphate from seawater under eutrophic conditions. The current paper deals with a promising new approach to improve the utilization of some industrial solid wastes such as BFS and zeolite synthesized from fly ash [ZFA(Fe)] by their solidification to cylindrical porous carriers using a hydrothermal hot-pressing (HHP) method.
Attempts to produce porous carriers using an arranged HHP method with different porosities (24%, 40% and 52% (v/v)) were carried out. Physical properties of carriers such as porosity, compressive strength and height have been investigated. Laboratory studies showed strong evidence that the porous carrier was very selective towards phosphate and ammonium. The results demonstrated the role of porosity in enhancing phosphate and ammonium adsorption by the increase of the surface area per weight. The estimates of the parameters and the correlation coefficients according to the Freundlich equations revealed that adsorption was related to the porosity of carriers and phosphate and ammonium were adsorbed well on the carriers having large porosity.
The results suggested that developing carrier with high porosity was a promising way to enhance nutrients adsorption. 相似文献