Main factors causing activated sludge floating

Source: http://www.cngzet.com release date: 2015-10-13

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(1) surfactant and excess grease compounds

This type of material can affect the stability and permeability of the cell membrane, so that some of the essential components of the cell loss and lead to microbial growth arrest and death. When the aeration tank in the water with a great deal of this kind of material, will produce a large number of foam, these bubbles easily agglomeration in zoogloea, the proportion of activated sludge reduce float. In addition, when in water containing oil is too high, after aeration and mixing, the oil will agglomeration in zoogloea surface, hypoxic cell death, resulted in decrease of specific gravity and buoyancy.

(2) PH shocks

Too high or too low pH will affect the activated sludge microbial extracellular enzymes and exist in cytoplasm and cell wall enzyme catalysis, and microorganisms on nutrient absorption. When the continuous flow aeration tank in pH < 4.0 or pH > 11.0, in most cases in activated sludge microbial activity inhibited, or loss of activity, and even death, so that the floating sludge.

(3) the effect of salt content

The influence of alkalinity on the activated sludge can not be eliminated by the adjustment of PH. The alkaline water PH, although neutralizing the alkaline substances, but produced a salt. The osmotic pressure of salt solution is also different, and osmotic pressure is one of the important factors that affect the survival of microorganisms. If the solution of the microorganism is in a sudden change, it will lead to the death of microbial cells.

(4) water temperature

The microorganism suitable for the active sludge is suitable for the temperature range of 15 to 35, and more than 45 of the activated sludge can cause most of the microorganisms in the activated sludge to float up (except for a long period of domestication or special microorganisms). In addition, the SBR process determination of temperature effects on intracellular enzyme activity test also found that temperature in 20, 30, 40 DEG C, the enzyme activity of better than 50 DEG C, enzyme activity decreased significantly.

(5) the toxic substrate

The substrates of the aerobic activated sludge microorganism are mainly including: high content of COD, organic compounds (phenol and its derivatives, alcohols, aldehydes and some organic acids), sulfides, heavy metals, etc..

High substrate concentrations can form stable compounds in the center of cell enzyme activities, which can not be close to the substrate, and can not be degraded, and even cause cell death.

After entering the cell, the heavy metal ions are mainly associated with the -SH binding to the enzyme or protein, which causes the inactivation or denaturation. Trace amounts of heavy metal ions can also accumulate in the cell eventually to the toxic effects of microorganisms (micro action).

The most common halide is iodine and chlorine, iodine is not reversible with the bacterial protein (or) the enzyme tyrosine to generate two iodine tyrosine, so that the bacteria inactivation. Chlorine and hydration of hypochlorite, the decomposition of strong oxidizing agent. And the organic matter in the wastewater, so that the original domestication of good and can degrade the organic poison of microbial reduce or disappear.

Microbial strain can effectively improve the problem of the activated sludge surface due to various reasons.