RCYTH Wuxi -20 tons/day - customized washing wastewater treatment system

Wuxi -20 tons/day - customized washing wastewater treatment system

In recent years, our city has strictly implemented the deployment requirements of the higher authorities on ecological civilization construction, and regarded the construction of urban sewage treatment facilities as a vivid practice of practicing harmonious coexistence between man and nature and assisting the "rural revitalization strategy". Through scientific planning, comprehensive layout, and unified bidding, sewage treatment facilities have been continuously improved, and have been awarded the honorary title of "National Rural Domestic Sewage Treatment Demonstration County". The ecological goals of "clear water, green banks, beautiful scenery, and ecology" are increasingly evident.

The amount of wastewater from washing production is about 20m ³/d. In order to protect the environment and eliminate pollution, the enterprise plans to build a set of sewage treatment facilities to ensure that the discharged wastewater after treatment meets the requirements《Pollutants from urban sewage treatment plantsEmission Standards（GB18918—2016）First levelBstandard requirements.

On behalf of the owner, our company has carefully analyzed the quality of the wastewater, summarized and referred to the experience of previous washing wastewater treatment projects, consulted a large amount of information, and referred to industry data to prepare the "Washing Wastewater Treatment Technology Plan" for review by relevant experts and selection by the owner.

1. Design concept

In the design of sewage treatment systems, the principles of technical applicability, targeted process measures, reliable and stable system, easy to start and stop operation, comprehensive savings in one-time investment and daily operating costs, maximum reduction of site occupation area, and maximum use of existing treatment facilities are adhered to; Design based on comprehensive analysis of similar sewage treatment technologies both domestically and internationally, especially practical experience from similar projects. At each stage of the actual process, sufficient comparisons were made among multiple options to determine the optimal process.

2. Design principles

(1) From the perspective of the enterprise, design closely based on the actual situation of Lianxi;

(2) Adopting mature process technology to ensure stable and reliable treatment effect;

(3) Minimize construction investment while ensuring compliance with emission standards;

(4) Strive to make the entire system easy to operate, manage, and minimize operating costs;

(5) Optimize the engineering structure and minimize the footprint as much as possible;

(6) Strictly implement relevant national laws, regulations, standards, and norms in the design.

2.3 Design Scope

The scope of this plan includes the design of all treatment processes for sewage treatment projects, including direct engineering such as equipment selection and installation, as well as indirect engineering such as design, commissioning, and training for this project; But it does not include auxiliary projects such as civil engineering construction, external power supply, water diversion, drainage and greening, roads, etc., nor does it temporarily consider auxiliary projects such as communication, transportation, power supply and distribution, heating, etc. for sewage treatment stations.

3. Design water quality and quantity

3.1 Design processing scale

The main purpose of this project is to treat the wastewater generated during the washing process of the water washing plant. The treated effluent meets the standard and is discharged outside. The amount of wastewater generated is 20m ³/d. The designed treatment capacity of the project's sewage station is 20m ³/d.

3.2 Design inlet water quality

The wastewater from this project belongs to high concentration organic wastewater. The raw water quality indicators are as follows, as shown in Table 1.

Table 1 Inlet water quality table

3.3 emission standard

The "Pollutant Discharge Standards for Urban Sewage Treatment Plants" (GB18918-2016) require Class 1B standards, and the relevant water quality indicators are shown in Table 2.

Table 2 Wastewater Discharge Standards

4. Process selection and description

4.1 Process selection

4.1.1Design Principles

(1) The washing process belongs to the intermittent production mode, with concentrated drainage time and uneven water quantity and quality. It is necessary to strengthen regulation to stabilize the sewage water quality and quantity, and avoid the impact of shock loads on biological treatment facilities;

(2) Wastewater has good biodegradability and fast biodegradation rate, making it suitable for biological treatment;

(3) Wastewater contains bacteria, viruses, parasite eggs, and some toxic and harmful substances, which must be disinfected before discharge;

4.1.2 Process Comparison and Selection

(1) Comparison and selection of biological treatment processes

Small sewage treatment plants generally adopt the following biological treatment methods:

1. Conventional activated sludge process

The conventional activated sludge process is widely used in large-scale sewage treatment, but due to its low load, easy sludge expansion, and difficulty in control and management, its use in small-scale sewage treatment plants has been decreasing in recent years.

2. A/O process

The A/O process uses activated sludge as a biological carrier and achieves oxygenation of wastewater through the action of fan oxygen supply and aeration. Mechanical agitation is installed in tank A, and the reflux liquid from tank O flows back to tank A. Denitrification reaction is carried out in tank A, reducing most of the nitrate nitrogen to nitrogen gas, and nitrogen gas is overflowed from the wastewater through agitation, achieving the goal of removing ammonia nitrogen; The effluent from tank A flows to tank O, which is equipped with blast aeration to remove most organic pollutants and convert most of the ammonia nitrogen in the influent into nitrate nitrogen; The concentration of activated sludge in the O-stage tank can be adjusted according to the needs of the wastewater, and the organic matter in the wastewater can be adsorbed, oxidized, and decomposed through the microbial flocs in the activated sludge; High removal rate of organic matter and ammonia nitrogen. However, due to the lack of an independent sludge return system, it is not possible to cultivate sludge with * function, and the degradation rate of difficult to degrade substances is relatively low; At the same time, in order to improve denitrification efficiency, it is necessary to increase the internal circulation ratio, which increases operating costs. In addition, the internal circulation liquid comes from the aeration tank and contains a certain amount of DO, which makes it difficult to maintain the ideal anoxic state in section A, affecting the denitrification effect and making it difficult to achieve a denitrification rate of 90%.

3. Contact oxidation method

The biological contact oxidation method is a traditional biochemical treatment method, in which the biological filler is a semi soft filler on a fixed bed. Using semi soft fillers as attachment carriers for microorganisms. The organisms are evenly distributed on the biological packing, which avoids the phenomenon of uneven distribution of microorganisms. At the same time, the organisms adhere to the surface of the packing and do not flow with water. Due to the strong agitation of the rising airflow, the biofilm is constantly renewed, thereby improving the purification effect. The contact oxidation method has the advantages of short treatment time, small volume, good purification effect, good and stable effluent quality, no need for sludge reflux or expansion, and low power consumption. Its main characteristics are:

High volumetric load and strong resistance to impact load;

Having the advantages of membrane method, with less residual sludge;

It has the advantages of activated sludge process, supplemented by mechanical equipment for oxygen supply, high biological activity, and short sludge age;

Can decompose substances that are difficult to decompose by other biological treatments;

Easy to manage, eliminating drawbacks such as sludge flotation and expansion.

In summary, the biological treatment of this project is planned to adopt the "hydrolysis acidification+contact oxidation method".

Significantly reduce BOD in wastewater under the decomposition of anaerobic bacteria₅It flows into the hydrolysis and acidification tank of section A, where the sewage undergoes hydrolysis and acidification, decomposing difficult to biodegrade large molecular organic matter into easily biodegradable small molecular organic matter. The effluent from the acidification tank in section A flows into the contact oxidation tank in section O. Due to the previous hydrolysis and acidification of the sewage, the biodegradability of the sewage is greatly improved, and a large number of microorganisms are used to remove organic matter from the sewage. At the same time, aerobic microorganisms are used to carry out nitrification reactions inside the wastewater, converting ammonia nitrogen (NH3-N) into nitrite (NO2-) and nitrate (NO3-), and discharging the effluent in compliance with standards.

4.1.3 Process selection

This process adopts a treatment process with biochemical treatment as the core, designed asRegulating tank+flocculation sedimentation+A/O+disinfection processThe process is mature and reliable, with simple operation and low investment and maintenance costs.

5. Other expenses

There is no need to increase the labor quota for this project, so there are no additional personnel salary and welfare expenses.

The electricity operation cost required for the operation of this project is due to the intermittent operation of the equipment

The total time is calculated based on 12 hours, with a running power of 4kw and an equipment operating power of tons for water treatment

The cost is approximately 0.48 yuan.

The PAC/PAM chemicals required for the operation of this project have a water treatment cost of approximately 0.13 yuan per ton.

The total cost required for the operation of this project is approximately 0.61 yuan per ton of water treatment.

6. Investment estimation

The civil engineering part shall be provided with design drawings by the design party, and the construction party shall carry out construction according to the drawings. The cost of civil engineering is not included in this investment quotation.

9. Noise issue

The main sources of noise are water pumps and fans. In the design, soundproofing and vibration reduction measures are taken to minimize noise transmission, and equipment with high noise such as water pumps are concentrated in the machine room. The equipment foundation is equipped with vibration reducing rubber pads, and flexible joints and vibration dampers are installed at the transition joints.

8. Sludge problem

After the biochemical method used in the project has been running for a period of time, the sludge absorbs nutrients from the sewage and proliferates, causing the sludge concentration to be too high, which affects the operation of the equipment. Therefore, during the operation of the system, the sludge needs to be discharged at regular intervals every day. The discharged sludge is pumped into the sludge tank by the sludge pump, and the sludge generated in the sludge tank is treated with limestone and transported by the environmental protection department to a location for deep treatment. Thus achieving reasonable discharge and treatment, avoiding secondary pollution.

9. Odor problem

The process used in the project will generate some odor. According to the characteristics of the project, the equipment is buried underground and covered with greenery on the ground. After being absorbed by plants, the odor can be greatly reduced. Moreover, the contact oxidation process used in the project produces a small amount of odor, therefore, this solution can effectively avoid the impact of odor on the surrounding environment.

10. Emergency measures for accidents

In case of equipment accidents, the environmental protection department should be notified and allowed to temporarily discharge the sewage directly. At the same time, the treatment equipment should be repaired and replaced in a timely manner to minimize the impact on the environment;

To ensure the normal operation of processing equipment, daily maintenance and inspection of the equipment should be strengthened, and maintenance or major repairs should be arranged during shutdown periods (holidays, etc.);

Establish standardized operating procedures and a sound alarm system.

11 Protection, energy conservation, and fire protection

safety protection

In response to the safety issues of the project itself, the following measures are taken in the design of the sewage station to ensure the safety of production:

(1) Each device is equipped with necessary protective measures to ensure safe operation.

(2) All electrical equipment shall be properly grounded and connected according to relevant national standards.

(3) The layout of electrical equipment and all transmission machinery and transmission machinery equipment should pay attention to leaving sufficient safe operating distance and setting up safety protective covers.

(4) The sewage treatment system is equipped with overflow and overflow pipelines to prevent equipment failure and accidents.

(5) Before the operation of the sewage treatment system, corresponding safety regulations should be formulated, and operators should receive necessary professional technical training before taking up their posts to ensure the normal operation of the sewage treatment plant.

energy saving

(1) The selected control system and instruments are adjusted reasonably to ensure efficient operation.

(2) Reasonably select the inlet pump and fan, so that the working efficiency of the pump and fan is always in the high efficiency zone.

(3) The system control equipment adopts independent control. According to the operating conditions, the operation of the equipment can be adjusted reasonably to achieve the goal of energy conservation and consumption reduction.

firefighting

According to the "Code for Fire Protection Design of Buildings" (GB116-87) and relevant national regulations and documents:

All buildings in the sewage station are designed with a second level fire resistance rating, and their walls, columns, beams, floors, stairs, ceilings, etc. are made of non combustible refractory materials.

The sewage station does not require outdoor fire hydrants, only a sufficient number of dry powder fire extinguishers need to be installed in the equipment room.

Transportation

Notify the owner by phone or fax one day before the shipment of each batch of equipment for automobile transportation.

The notice specifies: consignee, shipper, equipment number, shipment date, destination, name of goods and purchase order number, total volume of goods, total number of packages, and other information.

Installation service

After receiving the buyer's request for our company to send technical personnel to the site for installation, testing, and debugging, our technical personnel will arrive within one day. During equipment installation, we will follow the detailed construction drawings approved by the user and complete them on our behalf. We are responsible for the specific installation work, and the next debugging stage can only be carried out after we confirm that the installation is correct.

Run debugging services

After the equipment installation work is completed, the equipment enters trial operation, and we are responsible for implementing guidance and debugging work. After 15 consecutive days of satisfactory and successful commissioning of the equipment, the commissioning phase is over.

personnel training

We provide factory training for the management and operation personnel assigned by the user, which enables the trainees to effectively manage and operate their facility operations. The training content includes the understanding and experience of equipment installation, operation, maintenance, testing, and management related to daily operations of personnel in various positions, as well as other necessary training projects.

after-sales service

1. Quality Assurance

(1) Ensure that the provided equipment is manufactured using brand new, suitable materials and processes, without any defects or unused products.

(2) Having operable quality assurance procedures and corresponding documents, and strictly implementing the quality assurance procedure documents during the production of this batch of products.

(3) During the manufacturing process, the materials, connections, assembly, processes, overall and functional aspects of the equipment are tested and inspected to ensure compliance with the requirements of this technical document and confirmed design drawings.

(4) The supplier guarantees that the equipment provided can meet the requirements of the process parameters.

2. Inspection and acceptance

The inspection and acceptance of the equipment will be carried out in accordance with the corresponding standards. During the production process of the product, all stages from raw materials entering the factory, intermediate products to final products are inspected and accepted in accordance with relevant national and enterprise standards.

The Department of Ecology and Environment of Hebei Province reported the abnormal and excessive discharge of key pollution sources online monitoring data. Among them, the online monitoring data of Qingxun Sewage Treatment Co., Ltd. in Weixian County, Zhangjiakou City showed that it exceeded the standard for 10 consecutive days. The Department of Ecology and Environment of Hebei Province instructed the Zhangjiakou City Ecological Environment Bureau to conduct a comprehensive inspection and strictly supervise the implementation of rectification.

Weixian Qingrun Sewage Treatment Co., Ltd. is located in Yangzhuang Village, Weizhou Town, Weixian County. It was completed and accepted on January 5, 2011. The designed treatment capacity is 30000 cubic meters per day, and the actual treatment capacity is currently between 8000 and 10000 cubic meters per day. The discharge of water pollutants follows the Class A standard for urban sewage treatment plant pollutant discharge.

The Ecological Environment Bureau of Zhangjiakou City utilized the remote sampling system of Hebei Province to conduct remote sampling of the main discharge outlet of Qingxun Wastewater Treatment Co., Ltd. in Weixian County from 22:00 on May 24th to 8:00 on May 25th, with an interval of 2 hours. On May 25th, personnel conducted a comprehensive on-site inspection of the company and collected water samples from the main discharge outlet for monitoring.

*Upon inspection, it was found that the enterprise had not obtained a pollutant discharge permit to discharge pollutants, and had discharged without a permit. The monitoring report shows that COD ranges from 53 milligrams per liter to 105 milligrams per liter, exceeding the standard by 2.1 times; Ammonia nitrogen is 25.9 mg/L to 35.8 mg/L, exceeding the standard by 7.16 times; The total nitrogen content increased from 32.4 milligrams per liter to 40.5 milligrams per liter, exceeding the standard by 2.7 times. It is true that the company's sewage discharge exceeded the standard.

Wuxi -20 tons/day - customized washing wastewater treatment system