Stationary Distribution and Extinction of a Stochastic Microbial Flocculation Model with Regime Switching

In this paper, a stochastic microbial flocculation model with regime switching is developed and analyzed. By proposing a suitable stochastic Lyapunov function, the existence and ergodicity of a stationary distribution for the system are proved. Then, the extinction of microorganisms is discussed under appropriate conditions and sufficient conditions for extinction are obtained. Finally, the results of the theoretical analysis are illustrated by numerical simulation.

Research on the coagulant aid effects of modified diatomite on coal microbial flocculation

Diatomite was modified by chitosan to prepare modified diatomite, and the modified diatomite in an optimized ratio was utilized in coal bio-flocculation. The interaction behavior and flocculation mechanism of modified diatomite on coal slurry water were investigated by single factor experiments, infrared spectroscopy, Brunauer-Emmett-Teller (BET) measurements, and zeta potential measurements. The single factor experiments showed that when the amount of microbial flocculant added was 1.5 ml, the temperature of coal slurry water was 39 °C, the pH was 5, and the amount of modified diatomite was 0.2 g, after 30 min of sedimentation, the flocculation transmittance of the coal slurry water reached 84.3%. The infrared spectra showed that the -NH2 and -OH of the chitosan molecule had a polar interaction with the Si-OH bond in diatomite. The BET measurements showed that the specific surface area of diatomite was not a decisive factor affecting the flocculation effect. Zeta potential measurements indicated that the amino protonation of chitosan increased the isoelectric point (IEP) of modified diatomite. These results showed that modified diatomite has a good effect on coal bio-flocculation.

Decolorization Effect of Mycelium Pellet on Saline Azo Dye Wastewater

A fungus with efficient dye decolorization and that generates a microbial flocculation agent was isolated from a wastewater environment and screened. This bacterial strain imposed a significant decolorization effect on azo dyes. On the basis of morphological and microscopic features, the fungus was identified and named A-6. The results show that the decolorization process of the fungus exhibited two types of actions: adsorption decolorization of mycelium and flocculated decolorization of extracellular products in the dyes. The decolorization ratio reached 99.20%

Preliminary Screening of Microorganisms Producing Flocculent

In order to reduce the production cost of Microbial Flocculation，this article uses the cheap straw-inorganic nitrogen medium，directly domesticated and screened out a stable and efficient microbial flocculant producing strain B-15，which has better flocculation on kaolin clay suspension system. Preliminary identify as bacillu, the strain produce flocculant has flocculating rate of 81.08% for suspension.