Laboratory Experiments on Electroosmotic Dewatering of Vegetable Sludge and Mine Tailings

ABSTRACT

Vegetable wastes in the food industry are costly lo handle because of their high moisture content. while mill plant tailings in the mining industry contain large quantities of ultralines which are difficult io dewater.This paper describes the results of small scale electmosmotic dewatering (EOD) and combined field dewatering (CFD) measurements with model vegetable sludges and mine tailings.     

Effect of magnetic field on surface properties of Bacillus cereus CrA and its Extracellular Polymeric Substances (EPS)

The effect of magnetic field on surface properties of Bacillus cereus CrA and its EPS was studied by zeta potential and FT-IR spectrum. The weak magnetic fields of 6.0–10.0 mT promoted the predominant strain B. cereus CrA to form EPS. The weak magnetic field of 2.4–10.0 mT could improve the bio-adsorption efficiency of anions by decreasing the negative charge of the intact strain, while the magnetic field of 17.4 mT could increase the negative charge of the strain’s EPS by 20% and be responsible for the bio-adsorption of cations. Magnetic field could affect the band intensity and the slight shifting of peaks and the fluctuation of the bacterial absorption capability depended on the magnetic density. The magnetic field energy could affect the hydroxyl group and carboxyl group by forming hydrogen bonding, which were responsible for the adsorption ability of the strain and its EPS.     

Morphologies of electrochemically formed copper powder particles and their dependence on the quantity of evolved hydrogen

Copper powder particles formed by electrolysis under different quantities of evolved hydrogen were analyzed using the scanning electron microscopy (SEM) technique. It was found that the structure of the powder particles strongly depended on the quantity of evolved hydrogen — that is, two types of powder particles were formed, depending on the quantity of evolved hydrogen. One type of particle was formed during the electrodeposition of copper when the quantity of evolved hydrogen was insufficient to change the hydrodynamic conditions in the near-electrode layer. This particle type comprised dendrites constructed of corncob-like structures as the basic element. The other type of particle was cauliflower-like and was formed when the quantity of evolved hydrogen was sufficient to change the hydrodynamic conditions in the near-electrode layer. However, both types of particle consisted of agglomerates of copper grains. The only difference lay in the size of the copper grains of which the agglomerates were constituted. The size of the grains was a function of the electrodeposition overpotential and, consequently, the quantity of evolved hydrogen, with a tendency to attain a steady value when the electrodeposition overpotential was increased.