Integrated sewage treatment machine

smallIntegrated sewage treatment machine

Manufacturer Lusheng Environmental Protection——smallIntegrated sewage treatment machine

The basic form of bacteria: single cell, small individual, simple structure, without a true nucleus. Types: cocci, bacilli, spirochetes
Structure of bacteria: cell wall, cell membrane, inclusions, nuclear endosomes, cytoplasm, inclusions, flagella
Spores: Bacteria form a circular or elliptical dormant structure with thick walls, low water content, and strong stress resistance at a certain stage in their life history
Characteristics: Thick wall, low moisture content, not easily permeable, spores have the ability to resist heat, chemical drugs, radiation, etc
The relationship between cyanobacteria and water environment: When they grow vigorously in water bodies, they can turn the water blue, and some cyanobacteria can emit a grassy or moldy smell. The excessive proliferation of certain species of cyanobacteria can cause algal blooms, leading to water deterioration.

Types of primitive organisms: Caryopoda, flagella, cilia
Mild bacteriophages: After some bacteriophages invade host cells, their nucleic acids integrate into the host cell's nucleic acid and replicate synchronously. As the host cell divides, they are carried into the progeny host cells, and the host cells do not lyse
A bacteriophage that can cause bacterial cell lysis
The interrelationships between microorganisms: mutualism, symbiosis, antagonism, parasitism
Types of biological decomposition: biological removal, primary decomposition, environmentally acceptable decomposition, and * decomposition.

Backwashing is a widely used cleaning method, which can effectively remove gel layer and membrane pollution. By using gases, liquids, etc. as recoil media, a reverse force is applied to the membrane tube to remove pollutants adsorbed on the membrane surface and pores, thereby restoring the flux. During the backwashing process, if the membrane surface is rapidly rinsed at the same time to remove the loosened pollution layer, the cleaning effect can be improved. Generally, two ultrafiltration devices are operated in parallel, and the effluent from one ultrafiltration device is used to backwash the other ultrafiltration device. This should be done at a lower operating pressure (around 132kPa) to avoid membrane rupture. The backwash time generally takes (20-30) minutes. For roll ultrafiltration devices, timed backwashing is a necessary means to stabilize their water production. Studies have shown that for ultrafiltration devices that have difficulty regenerating due to a decrease in permeability during long-term continuous operation, soaking them in high-purity water for more than 10 hours before stopping and then performing hydraulic backwashing is an effective method to increase ultrafiltration permeability.

(2) Air flushing or aeration
The aeration method mainly uses an aeration control device to intermittently generate single large bubbles during aeration. The shear force and mass transfer efficiency of the large bubbles on the membrane surface during the rising process are significantly higher than those of small bubbles generated by ordinary free aeration. This provides a low-energy and high-efficiency method for membrane fouling aeration control, further improving the effectiveness of membrane fouling control, enhancing the selectivity and efficiency of membrane separation, reducing aeration energy consumption, decreasing membrane cleaning frequency and cost, and improving the service life of membrane components. Air flushing will produce two mobile phases, gas and liquid. This treatment method is simple and effective for cleaning membranes that are initially contaminated with organic matter.
(3) Isobaric flushing
Suitable for hollow fiber membrane ultrafiltration devices. When flushing, first reduce the pressure, close the outlet of the ultrafiltrate, and increase the rate of raw water (feed solution) entering. At this point, the pressure inside the hollow fiber cavity increases until it reaches the same operating pressure as the outer cavity of the hollow fiber, resulting in zero pressure difference between the two sides of the membrane. The solute molecules remaining on the membrane surface will be suspended in the solution and discharged with the concentrated solution.

(4) Negative pressure cleaning
Negative pressure cleaning is a process of creating negative pressure on the functional surface of a membrane through a certain amount of vacuum suction, in order to remove contaminants from the surface and interior of the membrane. Negative pressure cleaning is superior to isobaric cleaning and low-pressure high flow rate cleaning methods in some aspects. The negative pressure reverse flushing method is a method of flushing from the negative side of the membrane to the positive side, which is suitable for hollow fiber or capillary ultrafiltration membranes with dense layers inside and outside. This is an effective method that often coexists with risks. Once operated incorrectly, it is easy to crack the membrane or damage the bonding surface between the hollow fibers or capillaries and the adhesive, resulting in leakage.

Nitrifying bacteria are aerobic bacteria, including nitrifying bacteria and nitrifying bacteria. Living in aerobic water or sand layers plays a crucial role in the nitrogen cycling water purification process.
From a morphological perspective, there are also various forms, such as spherical, rod-shaped, spiral, etc., but they are all Gram negative bacteria without spores; Some bacteria have flagella that can move, such as nitrifying leaf fungi, which use flagella to move around their bodies; Some flagellates cannot move, such as nitrifying bacteria. Generally distributed in soil, freshwater, and seawater, some bacteria are only found in seawater, such as Nitrococcus and Nitrobacter.

Life activities
The life activity of nitrifying bacteria: Nitrobacter (also known as ammonia oxidizing bacteria) oxidizes ammonia to nitrite. Reaction equation: 2NH3+3O2 → 2HNO2+2H2O+158kcal (660kJ). Nitrobacter (also known as nitrifying bacteria) oxidizes nitrous acid into nitric acid. Reaction equation: HNO2+1/2 O2=HNO3, - Δ G=18 kcal. These two types of bacteria can obtain the energy needed for growth from the above oxidation processes, but their energy utilization efficiency is not high, so their growth is slower, and their average generation time (i.e. the time required for bacterial reproduction) is over 10 hours. Nitrifying bacteria play an important role in the natural nitrogen cycle. These two types of bacteria usually live together, avoiding the accumulation of nitrite in the soil and promoting normal growth of the body. Ammonia or ammonium salts in soil must be converted into nitrate through the combined action of the two types of bacteria, thereby increasing the nitrogen nutrition available to plants. To this day, no nitrifying bacteria have been discovered that can directly convert ammonia into nitric acid, so nitrification must be achieved through the joint action of these two types of bacteria. We know that nitrous acid is harmful to the human body because it can combine with some metal ions to form nitrite, which can then combine with amines to form nitrosamines with strong carcinogenic effects. However, when nitrite in the soil is converted to nitrate, it is easy to form nitrate, which becomes a nutrient that can be absorbed and utilized by plants. Under the action of nitrifying bacteria, there are often more acidic substances in the soil. These acidic substances can enhance the quick availability and persistence of various phosphate fertilizers in soil, prevent plant diseases such as potato scab, and even improve alkaline soil to a certain extent. So, the relationship between nitrifying bacteria and humans is very close. In agriculture, bacterial activity can be increased by deep plowing and loosening the soil, thereby increasing soil fertility. But nitrates are also highly prone to seep into groundwater through soil, becoming a potential source of pollution and posing a threat to human health. Therefore, in agriculture, both deep plowing and soil loosening methods can be used to increase bacterial activity, and nitrogen fertilizer enhancers (i.e. nitrification inhibitors) can be applied to reduce the activity of soil nitrifying bacteria, thereby reducing the loss of soil nitrogen fertilizer and environmental pollution.

Aerobic biological treatment is the process of utilizing the activity of aerobic microorganisms to decompose organic matter in wastewater into CO2H2O, NH3, and NO3- in the presence of sufficient dissolved oxygen in water. Generally, aerobic reactions are divided into activated sludge process, biofilm process (biofilter, biological turntable), contact oxidation tank process, oxidation pond process, etc. Li et al. treated wastewater from Daqing Oilfield using PVA biological fixation method, reducing COD from 2600mg/L to 240mg/L. The immobilized microorganisms can be reused, increasing the utilization rate of degrading bacteria during the treatment process. *Ming et al. removed large floating oil blocks through a primary air flotation pre biochemical unit; The fourth level biochemical treatment unit reduces the polymer content in sewage, removes emulsified oil and dissolved oil, and lowers the oil content and COD value of sewage; Secondary sedimentation unit, experimental process for settling bacterial bodies or biological deoxygenation. The experimental results showed that after pre biochemistry, the COD of the sewage decreased significantly, and after multi-stage biochemical treatment, the COD value gradually decreased. Finally, the COD of the settled sewage was below 110mg/L.