Acclimation method of biochemical sludge in wastewater treatment

Acclimation refers to the selection and induction of mixed microbiota to make microorganisms with the activity of degrading pollutants in sewage dominant. Sludge acclimation is often used in the sewage biological treatment process for the purpose of adding value to microorganisms and reaching a certain sludge concentration.

Activated sludge from sewage treatment equipment.

Acclimation conditions: microbial growth conditions can not occur sudden outstanding changes, conventionally speaking, there should be an adaptation process, the acclimation process should be as consistent as possible with the original growth conditions, when the conditions are not available, generally use conventional domestic sewage.

As a culture water source, the temperature of acclimation is not lower than 20, and the domestication is continuously exposed for 3-7 days.

Acclimation method of activated sludge of sewage treatment equipment:

1. After the acclimation conditions of activated sludge are met, under the condition that the continuous operation of Huai quietly has seen the effect, the method of increasing the amount of sewage inflow is adopted to gradually adapt the microorganisms to the new living conditions, and the size of the incremental increase is according to the anaerobic, aerobic process and site conditions.

2. Anaerobic, aerobic, hydrolysis and other biochemical processes are complex processes, each process will have its own characteristics, which need to be adjusted according to site conditions.

3. Prepare the necessary laboratory and operation of the original record report and the preliminary establishment of rules and regulations. From the beginning of the cultivation, gradually establish a more standardized organization and management model.

Ensure that the start-up and official operation are carried out in an orderly manner.

The cycle of biochemical culture depends on the water temperature and quality of the wastewater. When the water temperature is higher than 15, the process of cultivating bacteria is faster, and when the water temperature is lower than 15, the sludge acclimation time is longer, so the sludge culture and acclimation should be carried out in the period from May to November (Yangtze River Basin). As far as the water quality of wastewater is concerned, the biochemical cultivation time of non-toxic, harmless and easily biodegradable wastewater is generally 10-20 days, while the toxic and harmful, refractory and biodegradable wastewater requires a longer process, about 30-60 days, or even longer.

After the commissioning of clean water is completed, for wastewater with good biochemical properties, microorganisms can be domesticated directly with wastewater; For chemical wastewater or wastewater with poor biochemical properties, a step-by-step culture method should be adopted, and the specific steps are as follows:

1) Rapid proliferation. The purpose of rapid proliferation is to allow the sludge to grow rapidly onto the filler. Generally speaking, the purchased sludge will be damaged to varying degrees in the process of dewatering or transportation, and they will have a process of recovery and growth in the new environment, and they need to have a good living environment.

If it is domesticated directly with chemical wastewater at this time, the result will inevitably lead to a large number of microbial deaths. Therefore, the first stage can be used to use domestic sewage or glucose or dry flour to burn cooked paste (within the initial 3-5 days, every 100m3 biochemical tank volume can be put according to the proportion of adding 5-10 kg of dry flour) to cultivate bacteria, aeration twice a day, aerobic tank aeration for 8 hours each time, so that microorganisms can quickly recover and grow and reproduce, this method is called rapid proliferation method. During the rapid proliferation period, the wastewater in the biochemical tank can be discharged through the sludge acclimation pipe, and the aeration should be stopped before the water is discharged, and the water will be released after the sludge settles for 4-8 hours.

During the operation of the biochemical tank, when the microorganisms are subjected to a load shock, the COD removal rate or SV suddenly decreases, the rapid proliferation method can also be used to help the microorganisms recover and grow.

3) Wastewater acclimation. After the sludge grows to the filler, the dry flour added to the 100m3 biochemical tank can be increased to 20-30kg kg per day, and the biochemical inlet water or wastewater is pumped into the biochemical tank at the same time. The initial wastewater inlet can be pumped in at a rate of 1-2% per 100m3 biochemical tank volume, and then gradually increase the pumping volume of the wastewater in the proportion of 2% every two days until the designed wastewater inflow is reached.

With the gradual increase in the amount of wastewater pumped, the amount of glucose or dry flour or the amount of domestic sewage pumped should be reduced accordingly until the dosing is stopped, or waste alcohol can be added proportionally (1 kg of waste alcohol is counted as kg COD).

During the domestication of cultures, COD must be measured daily, and if a sudden decrease in COD removal rate or SV is found, the incremental increase in wastewater should be stopped immediately until the COD removal rate rises to more than 50% and SV no longer decreases.

When the aerobic tank is normally inlet into the wastewater, the COD removal rate can be maintained at more than 80%, and the COD concentration of the treated effluent is less than 200mg L, it can be considered that the biochemical tank has begun to work normally.

During the sludge acclimation period, it is important to avoid the impact of load (such as large volume of water and high concentration), and after the cultivation is completed, normal operation can be carried out.

Acclimation of activated sludge is usually done for organic industrial wastewater that contains toxic or refractory biodegradation. Generally, the activated sludge is cultivated by domestic sewage or fecal water in advance, and then domesticated with the sewage to be treated, so that the activated sludge can adapt to the water quality characteristics of the treated sewage. Activated sludge that has been domesticated for a long time may even oxidize and decompose some toxic organic matter, or even turn it into nutrients for microorganisms.

The acclimation method can be divided into two types: asynchronous and synchronous, and the result of both acclimation methods is to accept all industrial wastewater. The asynchronous acclimation method is to use domestic sewage or fecal water to cultivate and mature the activated sludge, and then gradually increase the proportion of industrial wastewater in the mixture. The sludge concentration and treatment effect should not decrease by more than 10% with each change in the ratio, and after 7 to 10 days of operation, it can return to the optimal value.

The synchronous acclimation method is to use domestic sewage or fecal water to cultivate activated sludge at the same time, start to add a small amount of industrial wastewater, and then gradually increase the proportion of industrial wastewater in the mixture.

For industrial wastewater with good life, less toxic components and more comprehensive nutrition, the synchronous acclimation method can be used to cultivate and acclimatize sludge at the same time. Otherwise, asynchronous acclimation must be used to completely separate nutrition and acclimation.

Activated sludge is a small brown flocculent particle that is the heart of the activated sludge treatment system, which is inhabited by a large number of active microorganisms, and under the action of these microorganisms, has the vitality to convert organic matter into inorganic matter.

Principle: The organic matter in the wastewater is oxidized and decomposed into inorganic matter by microorganisms.