Design scheme of wastewater treatment and transformation. Summary: The wastewater in the production process of leather factory mainly comes from the leather processing process, and the pollutants mainly include: wastewater discharged in the production process, which contains a lot of chemical raw materials such as protein, grease, fatty acid, dander, hair, salt, soda ash, lime, sodium sulfide, chrome tanning agent, acid, dye, etc. It belongs to high-concentration organic wastewater, with many kinds of pollutants, complex components, large coefficient of variation of water quality and quantity, and unpleasant odor. This kind of wastewater is characterized by a wide range of COD values, high temperature and easy odor generation. The factory has a simple sewage treatment facility, but with the development of production, it can't meet the treatment requirements. If this kind of wastewater is directly discharged into natural water, it will not only endanger the survival and development of aquatic ecosystem, but also directly threaten human health. In order to ensure the effective treatment and discharge of wastewater, it is necessary to improve the wastewater treatment facilities on the original basis. Entrusted by the factory, our company designed the wastewater treatment project with a serious and responsible attitude. After the implementation of this project, the wastewater will be strictly treated to prevent serious pollution to the receiving water body and realize the discharge or reuse up to the standard. 2. The existing sewage facilities have been running for many years, and the facilities are aging; Sewage can not meet the purification requirements, and the effluent quality is poor. The main problems are: ① there is no grid, which leads to a large number of large pieces of garbage in the regulating pool, which affects the post-treatment unit; (2) The process determines that the treatment load is too heavy and the treatment effect is unstable, which often leads to the failure to meet the discharge standards; (3) The lack of special sludge drying equipment makes the sludge huge and difficult to dispose of; ④ The surrounding environment is less green; ⑤ The original honeycomb filler in the sedimentation tank is glass fiber. Now, due to the falling of glass fiber reinforced plastic, a large amount of sludge is deposited in the honeycomb holes, which leads to poor sedimentation effect. 2. Solution Through on-site investigation and consultation with the personnel of this unit, the following methods are put forward: ① Install stainless steel grille; (2) Install a set of air flotation water treatment equipment in the later stage; (3) Transform the sludge tank and install the plate-and-frame filter press; ④ improving the surrounding environment; ⑤ Clean the intensified reaction sedimentation tank, repaint it, and replace the honeycomb inclined tube filler and bracket. 1. 1 Design principle (1) Strictly implement the national regulations on environmental protection to ensure that the effluent meets the relevant national and local pollutant discharge standards. (2) Adopt the mature and practical treatment technology in China at present, and meet the treatment target requirements stably and reliably. (3) The technical route is simple and clear, the operation and management are convenient, and the technological process has strong impact resistance. (4) Under the above premise, the investment is low and the operation cost is low. 1.2 design basis and standard (1) People's Republic of China (PRC) environmental protection law (2) Guangdong provincial regulations on environmental protection management of construction projects (3) People's Republic of China (PRC) (3) first-class standard in GB 8978-1996 (4) drainage engineering design manual (5) outdoor drainage design specification (6) provided by the owner. Design scope 1.4 Design objective According to Party A's requirements, the discharged water quality must meet the first-class standard in People's Republic of China (PRC) Integrated Wastewater Discharge Standard GB8978- 1996 and the first-class standard in Guangdong Water Pollution Discharge Standard DB4426-89. The discharge standard requires: pH: 6 ~ 9 CODcr: ≤100 mg/l BOD5: ≤ 30 mg/l SS: ≤ 70 mg/l sulfide: ≤ 1.0mg/l animal and vegetable oil: ≤20mg/l 2. 2. 1 Drainage quantity and water quality of the overall wastewater treatment plan. According to the monitoring result report of Guangzhou Tianhe Leather Factory by Guangzhou Tianhe District Environmental Monitoring Station, our previous engineering experience and referring to the wastewater quality of similar factories, Determine the wastewater quality, treated water quality and discharge standard as follows: Table 1: Inlet and outlet water quality: pH CODcr (mg/l) BOD5 (mg/l) SS (mg/l) sulfide (mg/l) animal and vegetable oil (mg/l) Design influent concentration is 8 ~ 9 650 220 230/kloc-. The engineering principle is: (1) Due to the uneven discharge of workshop wastewater, the mixed wastewater pretreated in the workshop flows into the regulating tank to adjust the flow and balance the water quality after removing large impurities through the grid. The aeration pipeline is arranged in the regulating tank for pre-aeration, which can make the wastewater mix evenly on the one hand, and remove the reducing substances in the wastewater on the other hand, so as to ensure the effect of subsequent treatment. (2) The wastewater in the regulating tank is pumped into the reactor by a pump and flows into the reactor for precipitation, so as to remove most of the suspended solids and petroleum. (3) The wastewater after precipitation treatment flows into the air floatation treatment unit, and after air floatation treatment, the water after pollutant removal treatment can reach the standard for discharge or reuse. (4) The sludge produced by this treatment system is dewatered by the filter press and then transported outside. The process has the characteristics of high efficiency, low energy consumption, low operating cost, stable operation, small floor space and simple operation. The process flow is shown in the following figure: 3. Design parameters of wastewater treatment process 3. 1 description of main buildings and structures 1) Function of regulating tank 1: balance water quantity and water quality, make subsequent purification treatment work normally, and install lifting pump in the tank to lift wastewater to the next treatment unit. Specification: original structure: original equipment: original lifting pump; 2) Coagulation reaction sedimentation tank function: wastewater is precipitated by coagulation reaction, and the wastewater flows to the next treatment unit by itself. Specification: original structure: steel structure equipment: original 2) design flow of air flotation equipment: q = 65438+1100m3/h air flotation process adopts finalized secondary air flotation equipment. 3) Sludge tank function: storing sludge. Specification: 2.0×2.0×2.0m, surface load 0.95m3/(m2 h) Equipment: 1 4 sludge pumps. Civil engineering design 4. 1 Civil engineering design principle (1) meets the functional requirements, making the layout of sewage treatment station compact and reasonable, and easy to contact under the condition of smooth process flow. (2) The layout is reasonable, striving to be in harmony with the surrounding environment of the factory. (3) Meet the requirements of the overall planning of the factory. (4) Make full use of topography, geology and hydrological conditions, choose reasonable structural type and foundation treatment, and strive to be economical and reasonable. (5) Reasonably determine the design ground form and design elevation, and do a good job in site leveling, drainage and flood control. (6) Reasonable station greening arrangement can achieve the artistic landscape effect of greening gardens. 4.2 Key points of structural design (1) The foundation type design is temporarily considered as natural foundation, and the bearing capacity of foundation should be calculated and determined in detail according to the actual engineering geological data during construction design. (2) Waterproof concrete is poured in the pool, and the impermeability grade is S6. 4.3 The general layout (1) shall be arranged according to the overall layout of the plant, the designated station site, the wastewater population and the position of the discharge port, and the wastewater treatment process, so as to make the layout reasonable and achieve the purpose of overall beauty while meeting the process design requirements. (2) Fully combine the terrain, geology, hydrology and other conditions of the site, vertically arrange the roads of the station buildings and structures, and select the appropriate elevation as the station elevation to minimize earthwork excavation. 4.4 List of Buildings and StructuresNo. Nominal specification (L×B×H) MM Quantity Structure Type Remarks 1 Grille Pool 1000×300×300 1 Reinforced Concrete 2 Regulating Pool 1 Reinforced Concrete 4 Sludge Pool 2000× 2000× 2000/ Power distribution and automatic control 5. 1 design basis (65438) (2) Code for Design of Industrial and Civil Power Supply Systems (gbj 52-83)(3) Code for Design of Low-voltage Distribution Devices and Lines (gbj 54-83)(4) Code for Design of Industrial and Civil General Equipment Electric Devices (GBJ 55-83) 5.3 The power supply and load wastewater treatment station is equipped with 380/220V and 50Hz power supply (provided by Party A). The distribution system adopts three-phase five-wire system and single-phase three-wire system, and the load level is three. 5.4 Power cable for power distribution and cable laying (1) is VV type, and control cable is KVV type. After pipe laying, the power cable or control cable to be directly buried is VV22 or KVVP. 5.5 Lighting distribution is provided by power distribution cabinet, with 0 ~200V power supply as indoor and outdoor lighting power supply, and BVV line is laid along the wall through flame-retardant plastic trunking. 5.6 Lightning protection grounding (1) Use the foundation reinforcement of the building as a natural grounding body, or install an artificial grounding electrode, and the grounding resistance should be less than 10 ohm. (2) The building adopts lightning protection zone and short lightning rod. 5.7 Automatic control This project must set up a total electric box in the ground distribution room to control the electricity consumption of the whole wastewater treatment. According to electrical requirements, the operating equipment is equipped with automatic facilities such as overcurrent, overload, phase failure and short circuit protection, which is reliable in operation and long in service life. 6. Project investment estimation