Experiments were conducted to evaluate the influence of sediment concentration, slope and discharge on sediment deposition rates and patterns associated with a reduction in bed slope. Analysis of the data shows that up to a certain unit discharge a simple settling equation without a transport term gives a good prediction of the sediment delivery ratio and the grain-size distribution of the depo...

  In this paper, modeling and optimization of Fischer-Tropsch Synthesis is considered in a fixed-bed catalytic reactor using an industrial Fe-Cu-K catalyst. A one dimensional pseudo-homogenous plug flow model without axial dispersion is developed for converting syngas to heavy hydrocarbons. The effects of temperature, pressure, H2 to CO ratio in feed stream, and CO molar flow on the mass flow r...

Two laboratory scale fully aerated continuous flow wastewater treatment systems were used to compare the removal of five benzotriazoles and one benzothiazole by suspended and attached growth biomass. The activated sludge system was operated under low organic loading conditions. The moving bed biofilm reactor (MBBR) system consisted of two serially connected reactors filled with K3-biocarriers. ...

The influence of burrow spacing on sedimentary nitrification and denitrification was simulated experimentally using sediment plugs of different thicknesses immersed in aerated seawater reservoirs. Different plug thicknesses mimic different distances between oxygenated burrow centers and produce similar changes in aerobic–anaerobic reaction balances as a function of diffusive transport scaling. ...

The removal of biological nitrogen from a synthetic wastewater with different ammonium nitrogen concentrations (50 and 100 mgN-NH4/L) by a nitrification and denitrification process using a sequencing batch biofilm reactor (SBBR) with liquid-phase circulation was studied. The system with a total working volume of 4.6 L (3.7 L in the reactor and 0.9 L in the reservoir) treated 2.1 L of synthetic ...

A new continuous-flow automated enzymatic method suitable for the direct determination of creatinine in physiological samples is described. The proposed system utilizes an on-line gas predialysis unit in conjunction with a flow-through enzyme reactor coil and a potentiometric ammonia detector. The enzyme reactor contains immobilized creatinine iminohydrolase (EC 3.5.4.21) which converts creatin...

The East China Sea (ECS) is a region with shallow continental shelves and a mixed oceanic circulation system allowing sediments to deposit on its inner shelf, particularly near the estuary of the Yangtze River. The seasonal northward-flowing Taiwan Warm Current and southward-flowing China Coastal Current trap sediments from the Yangtze River, which are accumulated over time at rates of up to a ...

the problems of land degradation and soil loss are among the major problems of watersheds in iran. for erosion andsediment estimation one can use statistical and empirical methods. for doing this, land unit map and the map of effectivefactors should be prepared. for erosion and sediment estimation one can use statistical and empirical methods. however,these empirical methods are usually time co...