Sewage treatment plant internship report

1. Internship purpose:

Production internship is an important practical part of student university study. Internship is a must-have course for every college graduate. It not only allows us to learn a lot of knowledge that we can't learn at all in the classroom, but also broadens our horizons, grows our knowledge, and better learns what we learn in the future. Apply a solid foundation to practical work. Through production internships, I have gained more in-depth exposure to professional knowledge, further understanding the reality of environmental protection work, understanding the problems in the process of environmental governance and the difficult problems of conflicting theory and practice, and by writing an internship report, I have learned to apply comprehensively. Learn knowledge and improve your ability to analyze and solve professional problems.

2. Internship specific content:

West District Sewage Treatment Plant

Internship time: October 19, 2004 - November 29, 2004

1. Overview of the sewage plant:

The Guangzhou Economic and Technological Development Zone Wastewater Treatment Plant is a key environmental protection project invested by the Development Zone Management Committee. The main plant is located at No. 22, Zhicheng Avenue West, Guangzhou Economic and Technological Development Zone, covering an area of ​​78,600 square meters. The daily treatment of industrial wastewater and domestic sewage is 30,000 tons, and the long-term plan is 90,000 tons.

The Guangzhou Municipal Economic and Technological Development Zone Wastewater Treatment Plant General Factory broke ground in September 1992 and was completed and put into operation in August 1994. Since the establishment of the factory, the factory has adhered to the implementation of total quality management, taking human management as the key to quality management, production operation management as the core of quality management, equipment management as the basis of quality management, paying attention to every link and ensuring sewage treatment. The effluent water quality meets the design requirements and is superior to the national secondary emission standards of the design regulations. Pay attention to and strengthen technological transformation, and achieved good economic and social benefits in terms of energy conservation and consumption reduction. In 1999 and 2001, it was rated as the advanced unit of the national urban sewage treatment plant operation management and the advanced unit of Guangdong Province. The factory is a designated practice base for higher education institutions such as South China University of Technology and South China Normal University.

In June 2001, the factory successfully passed the ISO14000:1996 environmental management system identification and became the first urban sewage treatment plant identified by the ISO14000 environmental management system.

The plant has 8 pumping stations outside the sewage treatment plant, the Eastern District Wastewater Treatment Plant of Guangzhou Economic and Technological Development Zone, and the Yonghe Economic Zone Wastewater Treatment Plant of Guangzhou Economic and Technological Development Zone. The general plant uses the peripheral pumping station to enhance the form of water delivery, collecting and processing industrial wastewater and domestic sewage in the western area of ​​the Guangzhou Economic and Technological Development Zone. The main function of the plant is to be responsible for the safe and normal operation of the sewage pumping station, sewage treatment and sludge treatment, and to ensure that all the sewage entering the plant is discharged after being treated. The functional departments of the general plant include the director's office, the deputy director's office, the production department, the technical department, the comprehensive department, and the office.

The main positions of the production department include pump station operation, sewage treatment operation, sludge treatment operation, laboratory and warehouse management.

2. Process:

The West District General Plant adopts the traditional activated sludge process with the aeration of the impeller surface as the main body, all using domestic equipment. Sewage treatment uses various methods to separate the pollutants in the sewage or convert them into harmless substances, so that the sewage can be purified. Classification of sewage treatment methods:

Physical processing method. Such as filtration method, precipitation method.

Physical Chemistry. Such as coagulation precipitation method.

Biological treatment method. The use of microorganisms to adsorb, decompose, and oxidize organic matter in sewage, and degrade unstable organic matter into stable and harmless substances, thereby purifying the sewage. The activated sludge process is one of biological treatment methods.

The activated sludge process is the most widely used aerobic biochemical treatment technology for wastewater. It is mainly composed of aeration tank, secondary sedimentation tank, aeration system and sludge return system.

After the initial sedimentation tank, the wastewater enters the aeration tank simultaneously with the activated sludge refluxed at the bottom of the secondary sediment. By aeration, the activated sludge is suspended and fully contacted with the wastewater. The suspended solids and colloidal substances in the wastewater are adsorbed by the activated sludge, and the soluble organic matter in the waste water is used as a self-propagating nutrient by the microorganisms in the activated sludge, and is metabolized into substance cells and oxidized to become a final product. Undissolved organic matter needs to be converted into dissolved organic matter before it can be metabolized and utilized. The wastewater is thus purified. After purification, the wastewater and activated sludge are separated in the secondary sedimentation tank, and the upper layer of water is discharged. A part of the separated and concentrated sludge is returned to the aeration tank to ensure that a certain concentration of activated sludge is maintained in the aeration tank, and the rest is residual sewage. Mud, discharged by the system.

The influencing factors of activated sludge reaction are as follows:

BOD load rate, also known as organic load rate. Water temperature. PH value. Dissolved oxygen. Nutritional balance. Toxic substances

Aeration device:

Blast aeration device

Effluent treatment efficiency

COD
544
48.1
91.2

BOD5
270
9.8
96.4

SS
278
28.7
89.7

Main structures:

No. Structure Name Structure Type Specification Effective Volume Quantity

1
Aerated grit chamber aerated grit chamber
13.5×2.5×3.78
109
1

2
One settling tank radial flow sedimentation tank
D=20, H=5.65
1104
2

3
Aeration tank surface aeration biochemical pool
12×12×4.5
648
10

4
Second settling tank radial flow sedimentation tank
D=34, H=4.15
3282
2

5
Concentration tank gravity concentration tank
D=9, H=8.6
365
2

Major equipment

Equipment Name Model Specification Manufacturer Quantity Remarks

Grill cleaning machine
XGS1350-1200
Tangshan Qingyuan Environmental Protection Company
1
Pitch 10mm, pitch 100mm

Sand water separator
LSSF-260B
Nanjing Lanshen Pump Group
1

a sinking mud scraper
D20
Jiangdu Water Supply and Drainage Equipment Factory
2
Single arm peripheral drive auger scraper

a sinking tank drain pump
AS55-4CB
Nanjing Lanshen Pump Group
2

Aerator
PE150
Anhui First Textile Machinery Factory
10
SIEMENS frequency converter stepless speed regulation

Sludge return pump
WQ-300-15
Nanjing Lanshen Pump Group
4

Second sinking tank scraping machine
D34
Jiangdu Water Supply and Drainage Equipment Factory
2
Double-arm peripheral transmission augmented suction suction machine

Belt filter press
DYL-2000
Henan Mall Environmental Protection Factory
2
POWTRAN-RICH frequency converter stepless adjustment of filter belt speed

Roots Blower
SSR-100
Shandong Zhanghuang Machinery Industry Co., Ltd.
2
SIEMENS frequency converter stepless speed regulation

Excess sludge pump
AS75-4CB
Nanjing Lanshen Pump Group
2

Filter belt flushing pump
IS65-40-250
Hubei Shishou Pump Factory
2

Sludge pump
80WJ4012
Shanghai Ligong Pump Co., Ltd.
2
Chemical corrosion resistant pump, SIEMENS frequency converter stepless speed regulation

Dosing metering pump
JD
Tianjin General Machinery Factory
2

Air compressor
V-0.3/10
Guangzhou Tianhe Overseas Chinese Enterprise Company Huatong Compressor Factory
1
Mobile air compressor

Chlorine dioxide sterilizer
HT908-500
Shenzhen Ou Taihua Co., Ltd.
1

Main laboratory items:

Chemical oxygen demand COD
Biochemical oxygen demand BOD5
Aeration tank mixture MLSS
Reflux sludge MLSS
Suspended SS

PH total nitrogen TN
30 minutes settlement ratio SV
Sludge Index SVI
Ammonia nitrogen NH3-N

Total phosphorus TP
Phosphate PO43--P
Moisture content organic chloride

Eastern District Wastewater Treatment Plant Overview:

Visit time: November 28, 2004 morning

1. Factory overview:

The Eastern District Sewage Treatment Plant is located at Hongguang Road, East District of Guangzhou Economic and Technological Development Zone. It was built by the Guangzhou Economic and Technological Development Zone Management Committee using Austria's international payment. The first phase of the design process is 26,000 tons/day. The industrial and domestic sewage in the eastern region is treated. The SBR process is adopted. Basically, imported equipment is used, and the sewage enters the plant in a self-flowing manner.

2. Process:

The sequencing batch activated sludge process or the gap activated sludge process, referred to as the SBR process, is a relatively attractive wastewater treatment process in the activated sludge treatment system in the past decade, and the translation is based on the program. Batch treatment of sewage treatment.

SBR is a variant of the current activated sludge process. Its reaction mechanism and the removal mechanism of pollutants are basically the same as those of the traditional activated sludge process, and only the operation is different.

The SBR mode of operation consists of five basic processes: influent, reaction, sedimentation, effluent and standby. From the beginning of the inflow of sewage to the end of the standby time, it is counted as one cycle. In one cycle, all processes are carried out sequentially in a reaction tank equipped with an aeration or agitation device, and this cycle of operation is repeated over and over again to achieve the purpose of continuous sewage treatment.

Influent process: The influent process is the process of receiving sewage from the reaction tank.

Reaction process: After the wastewater is injected to a predetermined volume, aeration or agitation is performed to achieve the reaction purpose.

Precipitation process: stop aeration and agitation, and the activated sludge fluff is subjected to gravity sedimentation and supernatant separation.

Drainage process: The supernatant after the discharge of the activated sludge is discharged, and is discharged to the lowest water level as the treated effluent. Most of the activated sludge settled at the bottom of the reaction tank is used as the return sludge in the next treatment cycle, and the excess excess sludge is discharged.

Standby process: the period from the precipitation to the beginning of the next cycle.

SBR process equipment and devices

Decanter: electric mechanical rocker arm, sleeve type, siphon type, rotary type, float type, etc.

Aeration device: mechanical aeration, blast aeration.

Valves, mud removal systems.

. Automatic Control System.

The characteristics of the SBR method are as follows:

The SBR method concentrates several steps of influent, aeration, sedimentation, drainage and idle regeneration in the biochemical treatment process in one equipment or pool. Therefore, the basic process of treatment is the adjustment tank → SBR, and the process becomes very Short, less equipment, easy to operate and repair.

In SBR, in addition to aerobic biochemistry with aeration, there is also a longer period of aerobic microorganisms that do not withstand the organic load regeneration period, as well as the hydrolysis process of anaerobic microorganisms. Therefore, the SBR method has good sedimentation performance and clear water. Therefore, it is possible to maintain the high sludge concentration of the SBR, thereby obtaining a high load, and having an extraordinary treatment efficiency and the ability to treat difficult biochemical wastewater.

During the operation cycle of SBR, the time of water, aeration, sedimentation, drainage, idle, etc. can be adjusted according to the actual conditions of water quality and water quantity, so it is adaptable and convenient for debugging and normal operation.

Since the sludge has a regeneration process and can maintain a high concentration, the sludge is not only good in character, easy to dehydrate and dry, and has a low sludge yield.

SBR not only has a large biomass, but also is rich in biology, so it has a good ability to denitrify.

Due to the short process and less equipment, the second sinking tank, the scraper and the connecting pipeline are eliminated, so the capital investment is saved.

3. Process flow chart:

Yonghe Sewage Treatment Plant Overview:

1. Factory overview:

Yonghe Sewage Treatment Plant is located beside Yongshun Avenue, Yonghe Economic Zone, Guangzhou Economic and Technological Development Zone. The wastewater treatment capacity of the first phase is 2000 tons/day, mainly using an integrated sewage treatment device with biological contact oxidation process as the core, supplemented by the thickness. Pretreatment facilities such as grate machines and grit chambers are used to treat sewage from industrial waste water in the Yonghe Economic Zone. The second phase of the project is currently under construction. The second phase of the project uses a flexible biochemical wastewater treatment system with a daily sewage treatment capacity of 6,000 tons.

2. Process

The biofilm method is the same as the activated sludge method and belongs to the aerobic biological treatment method. However, the activated sludge method relies on the activated sludge suspended in the aeration tank to remove organic matter, and the biofilm method relies on microorganisms fixed on the surface of the solid medium to remove organic matter, and thus the method is also called biological Filtration method.

The biofilm method has the following characteristics: microorganisms immobilized on a solid surface have strong adaptability to changes in wastewater quality and quantity of water; compared with activated sludge method, management is convenient; since microorganisms are fixed on the surface of solid medium Even microorganisms with a slower rate of growth can live, thus forming a stable ecosystem; the more high-nutrient microbes, the less the amount of sludge naturally. It is generally believed that the biological filtration method has less excess sludge than the activated sludge process.

Of course, since the amount of microorganisms immobilized on the surface of the solid medium is difficult to control, the stretchability is poor in the operation operation; and because the surface area of ​​the filter material is small, the BOD volume load is limited, and the space effect is poor; in addition, the natural ventilation is used in the biofilm. The inner layer tends to form an anaerobic layer, thereby reducing the effective volume with a purifying function. However, due to the successful development of new process new filter materials, biofilm process is still widely used as a good aerobic biological treatment technology.

The biofilm method is divided into the following three categories:

. Wall-type biofilm method. Waste water and air flow along a fixed or rotating biofilm on the surface of the contact medium, such as biofilters and biological turntables.

Immersion biofilm method. The contact filter material is fixed in the aeration tank, completely immersed in water, and is blasted by aeration, such as contact oxidation.

Flow bed type biofilm method. A small particle size contact medium such as activated carbon or sand to which a biofilm is attached is suspended and flowed in the aeration tank.

3. Process flow:

The following figure is a schematic diagram of the process of the first phase of the Yonghe Wastewater Treatment Plant:

The design of the inlet and outlet water quality of Yonghe Sewage Treatment Plant is compared with the actual situation.

Project design influent design effluent actual water inlet range

BOD5
180
30
15~40

COD
300
80
60~140

SS
250
70
50~150

grease
30
10
Not tested

III. Internship summary:

The internship at the Whampoa Development Zone Wastewater Treatment Plant allowed me to learn the process of the activated sludge process to the maximum extent possible during the student phase. The activated sludge process is currently the aerobic biochemical treatment technology commonly used in urban and industrial wastewater treatment. The process flow is relatively simple, the treatment cost is low, the treatment effect is good, and the BOD/COD removal rate is high, so it can be widely favored. With the improvement of the process technology, the sequencing batch activated sludge method has received more and more attention. And the application of the .SBR method is highly demanding for electrification and automation, and has extraordinary processing efficiency and ability to handle difficult biochemical wastewater, greatly saving labor and land area, and is a relatively advanced and promising treatment process.