Project of water disposal of the city 44.6 thousand inhabitants

Contents

1. GENERAL PART

1.1. Introduction

1.2. Source Data

1.2.1 By settlement

1.2.2. By industrial enterprise:

1.2.3. By Water Facility

1.3 Design Part

1.3.1. Natural climatic conditions

1.3.2. Justification of design solutions

2. DESIGN AND PROCESS PART

2.1. Settlement drainage network

2.1.1. Estimated wastewater flow from the city

2.1.2. Determination of estimated wastewater flow rates

from a business

2.1.2.1.Purpose effluents

2.1.2.2. Shower drains

2.1.2.3. Production effluents

2.1.3. Determination of waste water flow rates for network areas

2.1.4. Hydraulic calculation of drainage network

2.1.5. Main manifold profile

2.1.6. Effluent inflow and outflow

2.1.7. Determination of pump head

2.2. Calculation of wastewater treatment facilities

2.2.1. Determination of average concentrations of total runoff contaminants

2.2.2. The cited population

2.2.3. Estimated consumption of domestic wastewater from residential

parts of the city and the industry. predpritiya

2.2.4. Wastewater treatment

2.2.4.1. Choice of Waste Water Treatment Scheme

2.2.4.2. Calculation of the receiving chamber

2.2.4.3. Calculation of grids

2.2.4.4. Calculation of horizontal sand head with straight line

water movement

2.2.4.5. Sand dewatering. Calculation of Sand Sites

2.2.4.6. Calculation of the primary horizontal sump

2.2.4.7. Calculation of air tanks - displacers with regenerators

2.2.4.8. Calculation of the elements of the blower tank

aerotenok

2.2.4.9. Calculation of secondary radial settling tanks

2.2.4.10. Calculation of waste water post-treatment facilities

2.2.4.11. Drum Mesh Calculation

2.2.4.12. Calculation of post-cleaning filters

2.2.4.13. Calculation of Waste Water Disinfection Plant

2.2.4.14. Disinfection with liquid chlorine

2.2.4.15. Calculation of blender of Parshal tray type

2.2.4.16. Calculation of horizontal contact tank

2.2.4.17. Wastewater discharge to the reservoir

2.2.4.18. Sediment treatment stages and methods

2.2.4.19. Calculation of vertical seals

2.2.4.20. Precipitation stabilization facilities

2.2.4.21. Anaerobic fermentation in methantenes

2.2.4.22. Calculation of installations for mechanical dewatering of sludge. Precipitation dewatering by centrifugation

2.2.4.23. Backup sludge sites

2.2.4.24. Sand sites

2.2.4.25. Thermal treatment of sediment

3.OPERATIONAL PART

3.1. Sanitary protection areas for sewers

treatment facilities

3.2. Operation of the drainage network

3.3. Operation of sewage treatment and sediment treatment facilities

3.4. Chemical and technological control over the operation of the treatment plant

3.5. Automation of the treatment plant operation

3.6. Occupational safety

3.7. Protection of the environment and water bodies

4. ECONOMIC PART

4.1. Initial calculation data

4.2. Calculation of the length of the sewage network

4.3. Calculation of capital investments of the designed sewerage system

4.4. Definition of capital investments in equipment

and sewage facilities

4.5. Determination of annual operating costs

4.5.1. Materials (chemicals)

4.5.2. Electric power

4.5.3. Depreciation deductions

4.5.4. Wages of production workers (main and additional)

4.5.5. Workshop and general operating expenses

4.5.6. Maintenance of administrative and management personnel

4.5.7. Calculation of workshop and general operating expenses

4.5.8. Non-operational costs

4.6. Technical and economic indicators of the project

4.6.1. Average rate calculation

4.6.2. Settlement of Company Profit

4.6.3. Calculation of profitability indicators

4.6.4. Calculation of payback period

4.7. Taxes

List of used literature

Source Data

According to the village.

Directly on the territory of the city there is a wavy relief with fluctuations in absolute elevations from 210-234 m. In the middle of the city, a river flows from east to west, and in the western part of the city it turns south.

Soils on the territory of the city and adjacent areas are 4 m soup, 6 m sand, non-aggressive to concrete .

Groundwater depth - 8.0 m

All effluents of one main collector are collected by the GNS and pumped to treatment facilities, which are located at a distance of 540 m from the city.

Building density P = 450 people/ha

Water disposal rate n = 350 l ./person. day

Introduction

Water disposal is a complex of engineering structures and measures that ensure the collection and removal of contaminated wastewater outside settlements and industrial enterprises, their treatment, degreasing and decontamination.

The main contaminants of wastewater are physiological discharges of humans and animals, waste and discards obtained during the washing of food, dishes, rooms, laundry washing, as well as those formed in technological processes at industrial enterprises. Household and production waters contain a significant amount of organic substances that can rot, which is very dangerous for people, animals and fish.

To maintain sanitary well-being, it is necessary to remove sewage from the territory of settlements in order not to pollute the surrounding area and reservoirs. The most modern is the system for removing sewage pollution outside the populated areas through closed underground pipelines to the sewage treatment plant.

The task of the project is to design a drainage network, calculate and finalize the treatment facilities of the city located in the Ulyanovsk region.

The city's drainage system, which receives effluents from built-up areas, is a complex of the most complex terrestrial and underground structures and communications: networks, collectors, pumping stations, treatment facilities. This complex of structures should provide full and deep treatment of domestic and industrial wastewater of the city.

Design Part

1.3.2. Justification of design solutions.

The most widespread in was a complete separate sewage system. The advantage of a separate sewerage system is the established, well-developed construction technology (usually in two stages: at the beginning - a production and household network, then, as the city develops, a closed rain), the absence of separation chambers, built in most cases according to an individual project and the relatively low cost of treatment facilities. The main drawback is the discharge of all rainwater into the water channels within the settlement.

The drainage scheme is solved on the basis of the terrain of the city and climatic conditions. The drainage system for the city is accepted as complete separate according to the crossed scheme. The network is traced to a reduced face of the neighborhoods.

Section 11 of the GNS is designed to pass the total waste water consumption of the city and the industrial enterprise. Waste water from the main pumping station is supplied to treatment facilities via two pressure water pipelines of the same diameter.

Choice of Waste Water Treatment Scheme

The method of treatment of facilities is chosen depending on: the required degree of treatment of waste water, terrain, energy factors, the nature of soils, the size of the area for treatment facilities, the flow rate of waste water, the capacity of the reservoir, etc. We take as a scheme a plant with biological treatment of waste water .

Mechanical treatment of wastewater is carried out on grids, sandwiches and settling tanks. Discards from the grids are sent to the crusher, and crushed discards in the form of pulp are dumped back into the channel in front of the grids. The sediment from the primary settling tank is sent to the methane tank, from the secondary settling tank to the iliocompressant.

After settling, waste water enters the aerotank, where active sludge is supplied.

The contents of the aerotanks are constantly mixed with air, which is supplied by blowers.

The mixture of waste liquid and active sludge from the aerotank is sent to the secondary sump, where the active sludge is released from the liquid and its bulk is returned to the aerotank.

Excess active sludge from aerotanks is supplied to IOL, where its volume decreases due to separation of water, compacted sludge is pumped to methane tank.

The treated waste liquid is filtered in the post-treatment unit, then disinfected (chlorinated) in the contact tank and discharged into the reservoir.

According to the above calculation, the degree of waste water treatment for suspended substances and for BPC should be 87% and 94%. Thus, complete biological treatment, as well as post-treatment of wastewater, is accepted for design.

Structure of structures:

1. Mechanical cleaning: grids, horizontal sandwiches, primary horizontal settling tanks.

2. Biological cleaning: aerotanks, secondary radial settling tanks.

3. Disinfection: contact tank, Parshal tray, laboratory.

4. Sediment treatment facilities: vertical type ilobler, aerobic stabilizer (methane tank), centrifuges.

Stabilization of precipitation

As a result of stabilization, the biodegradable part of the organic substance of precipitation is destroyed, which ensures their resistance to decay and partial decontamination. Stabilization is necessary with long-term residence of precipitation in open areas (drying on silt sites, warehousing), as well as when using them as agricultural fertilizer without thermal drying.

Stabilization can be carried out under anaerobic conditions by fermenting precipitation in methantenes or aerobic conditions by aeration of precipitation in stabilizers.

Thermal treatment of sediment

Heat treatment is the heating of precipitation to a temperature of 170-220 ° C at a pressure of 1.2-2 MPa, corresponding to the pressure of saturated water vapors at a given temperature, with holding at these parameters for 30 120 minutes depending on the properties of the initial precipitation.

During the heat treatment, organic substances, mainly proteins, decay, their dissolution and the transition from the solid phase of precipitation to liquid. At the same time, the structure of precipitation, their ash content and partially chemical composition change, improved water recovery and neutralization of precipitation are achieved.

Both raw and fermented precipitates can be heat treated. Fermentation facilitates the process of heat treatment and allows the decomposition of organic, mainly fatty matter precipitates, and reduce energy costs by using on

heating of excess heat obtained from combustion of fermentation gases.

During heat treatment, specific resistance of deposits decreases from initial value to value allowing dehydration of precipitates on filter presses without treatment with chemical reagents.

Depending on the properties of sediments, the mode of their treatment and the devices used, the humidity of dehydrated sediments ranges from 40 to 75%. In addition to the electricity consumption for supply, dewatering and creation of the required pressure, the heating of precipitation requires thermal energy, the consumption of which depends on the mode of operation and productivity of the plants; with a fuel calorie content of 40MJ, it is 812 kg per 1 m3 of sediment. Heated sediments, oils, softened water or synthetic mixtures are used as heat carrier. In most cases, acute steam is used to warm up precipitation.

To maintain the required modes, the operation of the plants must be automated. Safety requirements shall be strictly observed when working at the plants.

The fermented sludge to be treated is supplied to the sludge flow rate control tank, from where it enters the crusher for grinding, and from it to the intermediate tank, from which it is taken by high-pressure pumps and supplied to the reactor through heat exchangers. In heat exchangers, the sediment is heated by the sediment discharged from the reactor. In the reactor, the heated precipitate is mixed with steam. Coming from the boiler room and maintained. The resulting gas is discharged from the top of the reactor through a special device, cooled and cleaned.

The precipitate treated in the reactor is sent through heat exchangers to the sealant sump, where its volume decreases. The packed sediment enters the intermediate tank, from where it is supplied to the filter presses. Dump water from the seal and filtrate from the discharge filters to the head of the treatment plant

Operational part

3.2. Operation of the drainage network.

The drainage network should ensure the uninterrupted reception and disposal of waste water from the territory of the settlement to their treatment or subsequent use for various purposes. The tasks of technical operation of the drainage network include: supervision of the state and

preservation of the network, devices and equipment on it; maintenance of the network, elimination, clogging, flooding; maintenance and overhaul, elimination of accidents; monitoring and supervision of operation of networks and facilities connected to the water disposal system, which are managed by subscribers; supervision of construction and commissioning of new network lines, facilities on it and subscriber connections; maintenance of technical documentation and reporting; studying the network, drawing up promising plans for the reconstruction and development of the network, taking into account the construction in the village.

Maintenance of the network provides for external and internal (technical) inspections of the network and structures on it - duke and connecting chambers, wells, pressure and gravity pipelines (headers), emergency outlets, racks and culverts under the drainage network, etc. External inspection of the network is carried out at least 1 times a month by bypassing the routes of the network lines and inspecting the external state of devices and structures on the network.

During bypasses and inspections of routes of network lines check: status of coordinate plates; external condition of wells, presence and density of covers adjoining, integrity of hatches, covers, necks, clamps and stairs by opening the covers of wells and cleaning them from garbage (snow, ice); the degree of filling of pipes, the presence of overpressure (flooding), clogging and other violations visible from the surface of the earth; presence of gases in wells (by readings of instruments or by odor); the presence of subsidence along the route of lines or near wells; the presence of rubble on the network route and at the locations of wells, tearing along the network route, as well as unauthorized work on the arrangement of connections to the network; The presence of lowering of surface or any other water into the drainage network.

Technical inspection of the internal state of the drainage network, devices and structures on it is carried out with the following periodicity: for inspection wells and emergency outlets - 1 times a year; for chambers, racks and crossings - at least 1 times per quarter; for collectors and channels - once every 2 years. Technical inspection of gravity headers and channels with diameters of 1.5 m or more is carried out by passing through them under condition of complete or partial cessation of waste water supply.

Technical inspection of the pressure manifolds is limited to checking the operation and adjusting the vantages, gate valves and outlets. On the basis of external and technical inspections of the drainage network, defective lists are compiled, estimate technical documentation is developed and current repairs are carried out.

The current repair on the network includes: preventive measures: washing and cleaning lines, cleaning wells (chambers) from pollution, sediments, etc.; repair works: replacement of hatches, upper and lower covers, insertion of clamps, replacement of stairs, repair of the well neck, lifting and lowering of hatches, maintenance and adjustment of gate valves, bathrooms, gates, etc.

Preventive cleaning of the network is carried out according to the plan developed on the basis of data from external and technical inspections of the network, with a periodicity established taking into account local conditions. For a network with diameters up to 500 mm inclusive, the cleaning periodicity is established, as a rule, at least 1 time per year. Preventive

cleaning of the network is carried out along the basins: starting from the upper reaches, the side lines are cleared first, and then the main ones. Cleaning of the network is carried out at line diameters: up to 200 mm - by washing (by water from the water supply network or by accumulating waste water in wells and its subsequent discharge); up to 500 mm - rubber balls or discs with diameters 50100 mm less than diameters of cleaned pipes; 5001600 mm - wooden balls with diameters of 100250 mm less than diameters of cleaned pipes; more than 1500 mm - wooden cylinders or balls with diameters 250500 mm less than diameters of cleaned pipes.

Overhaul on the network includes the construction of new wells, their complete or partial reconstruction; laying of individual sections of lines with complete or partial replacement of pipes; replacement of gate valves, vanes, bathrooms or their worn-out parts; repair of individual structures on the network, devices and equipment. Accidents on drainage networks are considered to be sudden destruction or blockages of pipes and structures on the network, resulting in the cessation of waste water diversion or flooding (with waste water pouring to the surface) and causing the need to open the pipes (excavation). Work on emergency repair on the drainage network is carried out by repair and emergency teams or operational personnel of the network service, depending on the structure of the production enterprise. In order to supervise the operation of subscriber networks and facilities and the conditions for discharging industrial wastewater into the settlement drainage system, a special inspection service for industrial wastewater disposal is organized as part of the production enterprise, which in its activities is guided by the SNiP "Rules for the protection of surface waters from pollution by wastewater" and "Instructions for the reception of industrial wastewater into urban sewage."

3.3. Operation of sewage treatment and sediment treatment facilities.

Control over the operation of the entire station consists in determining: the amount of water entering the structures; the amount of sand produced,

sludge, active sludge or gas; flow rate of air, steam, hot water; energy consumption for production needs; consumption of reagents (for disinfection); effect of the plant operation based on chemical and bacteriological analyses of incoming and treated waste water; doses of active sludge in aerotanks.

It is very important that the actual amount of water entering the structure corresponds to the estimated flow rate. The amount of waste water shall be measured by measuring

devices equipped with self-recording devices, and their recordings should be decrypted daily with the calculation of both the total inflow per day and fluctuations in hours of day. If all waste water is supplied to the treatment facilities by a pump station equipped with water meters, then the total inflow at the treatment facilities is not measured. Water meter readings of the pump station shall be communicated to the treatment plant regularly.

Power consumption at treatment plants is determined both by individual plants (blowers, silt pumps, scraper mechanisms of settling tanks, etc.) and by the plant as a whole. Motor operation counters (start, stop) are regularly recorded in the log.

The effect of the operation of the plant and its individual structures is determined by comparing the composition of waste water before and after the water comes out of this treatment facility.

In special cases, data on the amount of sulfates, phosphates, potassium, dense residue, calcination losses, as well as the level of radioactivity may be of interest. For bacteriological control, it is necessary to determine the number of bacteria in 1 ml of water at 37 ° C, the number of helminth eggs in raw and purified waste water. To characterize the sediment, its humidity and ash content (%), as well as the chemical composition of the sediment (amount of fats, proteins and carbohydrates, mg/l) are used.

Complete analysis of incoming and treated waste water is carried out at least once a decade.

Sampling for analysis of incoming to the station and treated waste water is carried out at certain intervals of time during the day, established by the technologist of treatment facilities.

Samples of water of individual structures are taken taking into account the time of its passage through the controlled structure. Since the composition of waste water varies by hours of day, it is desirable to take hourly samples once a month.

Of these, an average daily sample is made taking into account hourly fluctuations in inflows. Water samples for analyses are taken in the places established by the technologist from a constant depth of flow.

The waste water temperature is measured at the time of sampling for analysis and at least once a day.

Depending on the capacity and complexity of the treatment facilities, a dispatch service should be organized for them, which performs :

telephone or radio communication with duty posts; complete or partial remote control of facilities and units and monitoring of their operation; complete or partial software management of facilities and units "; complete or partial automation of technological processes at facilities or their individual parts and mechanisms.

To ensure uninterrupted operation of all facilities in the event of an accident with power supplies or failure of individual automation elements, remote automatic control of treatment facilities should be duplicated by manual control.

Regulation of the distribution of liquid to structures - grids, distribution trays, groups of settling tanks, etc. - can be carried out centrally. The pulse for opening and closing is given by the float device of the measuring tray or from the control panel.

For successful operation of aerotanks, it is necessary to regulate the air supply in them in accordance with the content of dissolved oxygen in waste water and with the degree of treatment of waste water. The aero tanks shall be provided with instrumentation to measure the air flow rate, as well as to determine the dissolved oxygen content at the beginning, middle and end of the aero tank. It is also necessary to measure and record the amount of return active sludge and its concentration (dose) in the aero tank. The waste water temperature shall be measured in the supply (near the aero tanks) and discharge (after the aero tanks) trays. The pH of the waste water is controlled.

In the operation of secondary settling tanks, it is of great importance to automate the release of active sludge depending on its specified level and humidity.

3.4. Chemical and technological control over the operation of the treatment plant.

Chemical and technological control is closely linked to the automation of treatment plants and the equipment of control and measuring equipment, is constantly changing and improving .

Minimum required level of control is defined by approved methods and instructions

Based on unified methods of wastewater analysis, it is possible to draw up an approximate mandatory (for compiling water-mass balances) list of indicators of the composition of initial, partially or fully treated wastewater.

Indicators of physical and organoleptic properties of waste water: temperature; turbidity; dilution colour; smell.

Indicators of sanitary and chemical assessment of waste water composition: pH of water; total content of impurities, including mineral; the concentration of suspended substances, including minerals; dry residue (content of impurities in filtered sample), including mineral nature; COD bichromatic; Full BOD; nitrogen compounds (total, ammonium, nitrite and nitrate nitrogen); phosphorus compounds (general, mineral).

Indicators of bacteriological pollution of wastewater: total content of saprophytic bacteria; coli-titer.

Specific contamination indicators: fats; oil and petroleum products; salts of heavy metals, etc.

In condensed products and sediments, moisture and ash content of the suspension, specific composition indicators, evaluation properties of a technological nature (C-potential of the dispersion system, forms of water bonding, etc.) are usually determined.

An accurate assessment of the amount of pollution allows you to draw up a water-mass balance of the treatment plant and reasonably maneuver production capacities. A balance of contaminants can be drawn up under the condition of expressing the concentration of contaminants through COD of embroidered, settled and filtered samples. It is advisable to conduct COD operational control by determining the BOD by the ratio of these values ​ ​ in wastewater.

Under conditions of suspended substances removal, COD is determined in embroidered and clarified (or filtered) samples, assessing the quality of purification by residual dissolved part of contaminants.

Determination of COD return streams (filtrates, fugates, silt water) makes it possible to quickly assess the quality of sludge dewatering and additional loads on the treatment plant. Control of this type will be significantly facilitated with the mass release of KhPKmeters. Proper sampling arrangements are essential.

Automatic samplers simplify this operation.

Manual sampling should take into account the following points: the volume of single samples should be proportional to the waste water flow rate, which should be reflected in the instruction or on the curve of the filling ratio of the tray (pipe) at the point of collection and the volume of the single sample. Sampling frequency must be

correspond to the nature of the changes in water inflow to the treatment plant. Individual volley admissions of contaminants shall not "slip" between two samples.

3.5. Automation of the treatment plant operation.

Objectives and objectives of OS automation

improving the quality of wastewater treatment, bringing the maximum permissible concentrations (MPC) of suspended and dissolved substances to regulatory requirements, and thereby ensuring a high degree of environmental protection from pollution;

reduction of power consumption per unit volume of treated effluents;

higher reliability of treatment facilities.

Fixed Asset Automation Objects and Scope

mechanical treatment complex (receiving chamber, mechanical grids, sandwiches, primary settling tanks, pumping stations of crude sludge), which provides purification of incoming effluents from mechanical and mineral impurities and removal of insoluble substances from waste water, which are in suspended and floating state, before supply to biological treatment;

biological treatment complex (aerotanks, sludge pumping stations, secondary settling tanks) designed to remove organic compounds from mechanically treated waste water under the influence of certain microorganisms;

blowing stations providing air supply to aerotanks to provide aerobic process and mixing of treated effluents;

sludge treatment area (mechanical dewatering shop for treatment of raw sludge and compacted sludge, thermal drying shop for thermal treatment of dewatered sludge);

areas of additional treatment of treated effluents (ultraviolet irradiation plants, desecration stations for effluents with sodium hypochlorite, etc.);

auxiliary and life support systems (power supply, ventilation, heating, fire alarm, access control and control, video surveillance, etc.).

Features of the OS as an automation object, namely:

the distribution of the facility in a significant area;

heterogeneity of the object (a large number of parameters and actuators requiring various control algorithms) has a significant impact on the architecture of the system and the choice of automation and dispatching equipment.

Implementation Results

Complex automation of KOS on the basis of rational organization of technological regimes and use of resource-saving technologies provides

increased efficiency of treatment facilities while maintaining a high level of treatment,

improving reliability and quality of process equipment operation due to automatic monitoring and diagnostics,

helps to reduce operating costs due to increasing the service life of process equipment and saving electric energy;

reduction of the share of manual labor and reduction of the number of employees.