Water Supply Treatment Facilities

Contents

INTRODUCTION

1 MEASURING THE EFFICIENCY OF THE TREATMENT PLANT

2 SELECTION AND JUSTIFICATION OF PROCESS DIAGRAM OF WATER TREATMENT AND COMPOSITION OF TREATMENT FACILITIES

2.1 Drawing up of high-altitude diagram of treatment facilities

2.2 Basic Provisions of Treatment Plant Layout

3 CALCULATION OF REAGENT FACILITIES

3.1 Calculation of coagulant dose

3.2 Calculation of flocculant dose

3.3 Calculation of Alkaline Reagent Dose

3.4 Calculation of main reagent facilities

3.4.1 Calculation of coagulant solution preparation unit

3.4.2 Calculation of flocculant solution preparation unit

3.4.3 Calculation of blowers and air ducts

3.4.4 Selection of reagent dosing pumps

3.4.5 Calculation of reagent warehouses

4 CALCULATION OF MAIN TREATMENT PLANT FACILITIES

4.1 Calculation of microfilters

4.2 Calculation of mixing device

4.3 Calculation of flocculation chambers

4.4 Calculation of settling tanks

4.5 Calculation of fast filters

4.6 Calculation of sand farm

4.7 Calculation of water disinfection plant

4.8 Calculation of clean water tanks

5 CALCULATION OF MAIN PIPELINES OF TREATMENT PLANT

CONCLUSION

LIST OF LITERATURE USED

APPENDIX A

APPENDIX B

APPENDIX B

Summary

In this course project, after analyzing the water quality indicators in the water supply source, a water purification scheme from the lake for drinking water supply of the settlement was developed. The main doses of reagents and units for their dosing were calculated. The selection and calculation of the main structures of the water treatment plant was made.

Introduction

The purpose of this course project is to develop a technological scheme for the purification of the natural waters of the lake and to calculate the main structures of the water treatment station that meet the modern level of scientific and technical achievements in the field of water treatment and provide for the purification of natural water up to the requirements of SanPiN 2.1.4.107401. "Drinking water. Hygienic requirements for water quality of centralized drinking water supply systems. "

As well as reagent facilities: basic doses of the necessary reagents, units for their dosing and warehouses for their storage. Reagents are necessary in order to bring the source water indicators to the requirements of sanitary standards, and make water suitable for drinking water supply.

Selection and substantiation of the process diagram of water treatment and composition of treatment facilities

The method of water treatment and the necessary composition of treatment facilities are established depending on the capacity and quality of water in the source, determined by physicochemical and bacteriological indicators and requirements of SanPiN 2.1.4.107401 "Drinking water. Hygienic requirements for water quality of centralized drinking water supply systems. Quality control. "

According to [1, item 6.9], the waters of this water supply source (lake) shall be:

average turbidity - M = 120 mg/l, which gives the amount of suspended substances in water;

- average chromaticity - C = 800, which determines the content of humus substances in water.

The combination of the necessary technological processes and structures constitutes a technological scheme for improving the organoliptic properties of water (clarification, bleaching, deodorization), ensuring epidemiological safety (disinfection) and conditioning its mineral composition (fluorination and defluorination, softening, etc.). In this case, the process diagram is:

- reagent, since. V> 500, M> 50 mg/l and Q> 5000 m3/d;

- by the effect of clarification - deep clarification, since purified water must meet the requirements of drinking water quality;

- by the number of technological processes - two-stage, since two main technological processes are performed here: settling and filtering;

- by the nature of the treated water movement - gravity (non-pressure). The movement of the source water through the structures is carried out by gravity. The level difference determines the head required to overcome hydraulic resistances inside the structure and in communications from one structure to another.

For medium turbidity and medium chromaticity waters, a two-stage water purification scheme is most effective, since it better brings water to drinking quality indicators than a single-stage one. Horizontal settling tanks are used in this process, as there are sharp fluctuations in temperature of treated water [5].

The composition of the facilities of the water treatment station of open water supply sources for household and drinking purposes, including the complex of structures necessary for the clarification, discoloration and disinfection of water, depends on the method of its treatment, i.e., whether the coagulant and other substances are used or the process is carried out without reagents. Preliminary selection of the main technological facilities of such stations can be made on the basis of the recommendations of Table 15 [1].

Since the content of plankton in the source water is 2550 kl/ml, which is more than the permissible norm in the flow chart (1000 kl/ml), it is necessary to provide for the installation of 2 microfilters in the building of the pump station of the 1st lift before supplying water to the mixers.

For the purpose of disinfecting water and reducing oxidability during water treatment, chlorination is used: chlorine is introduced before microfilters (preliminary) and after fast filters.

Procurement and dosing of reagents is carried out using equipment located in the reagent farm. After mixing the re-agents with water in the mixer, it is fed into a flapping chamber attached to the sump.

There are no flavors and odors, so special water treatment is not required.

The iron content and hardness of the source water do not exceed the standard values, and the fluorine content is not enough, therefore fluorination is required.

The above list of structures is exemplary, it can be changed and supplemented during detailed design development, as well as depending on the quality of water in the source and special requirements for treated water of consumers. In these cases, it is possible to include devices for special water treatment in the complex of structures.

Drawing up a high-altitude diagram of treatment facilities

When designing a water treatment plant in order to reduce the construction cost, it is necessary to adapt technological structures to the terrain as much as possible. To do this, a high-altitude structure diagram is compiled, on which the position (elevation) of water levels in various equipment used in the selected process diagram is established. It is a graphic image in the profile of the station structures with mutual correlation of the height of their location [5].

The preparation of the high-altitude diagram begins with the lowest located structure - a clean water tank (RCV). The mark of the highest water level in it is taken for economic and sanitary reasons 0.5 m above the surface of the earth. Then, set by head losses in equipment and connecting communications, there are required water level elevations in separate structures [5].

For preliminary high-altitude location of structures, losses on-pore are taken in accordance with paragraph 6.219 [1], and further calculations will clarify the location of the structures.

Head losses in structures and connecting communications are accepted as follows:

- on microfilters 0.5 m

- in reagent injection devices 0.2 m

- in hydraulic mixers (vortex type) 0.5 m

- in hydraulic chambers of flapping (vortex type) 0.4 m

- in sumps 0.7 m

- in quick filters 3.5 m

- in communications from microfilters to mixers 0.2 m

- in communications from mixer to settling tanks 0.4 m

- in communications from settling tanks to fast filters 0.55 m

- in communications from fast filters to RChV 0.5 m

Found water level elevations in each individual element of treatment facilities are accepted as specified in subsequent calculations.

The approximate high-altitude diagram of the treatment plant is shown in Figure A.1 of Annex A.

Main provisions of treatment plant layout

In the process of designing water treatment plants, along with the choice of water treatment methods, composition and types of individual structures and equipment, it is also necessary to select the most appropriate mutual location of all elements of the station on the general plan of the construction site. The layout of structures and equipment, as well as auxiliary premises, should provide for minimum investments in construction, convenience and cost-effectiveness of operation, uninterrupted operation, systematic expansion with increased water consumption [5].

The terrain ensures the gravity movement of water along the chain of treatment facilities under the condition of their least deepening and the least amount of earthworks, as well as easy removal and discharge of flushing waters.

To reduce construction costs, it is allowed to use the carrying capacity of structural elements of the main technological structures. The walls of the station building can be supported on the walls of sumps and filters, and the floors should be supported by columns located on the structures of the main structures. The construction of water treatment stations is cheaper when using prefabricated reinforced concrete and standard span spacing. When arranging the complex of technological structures, the office premises necessary for operation are taken into account, including dosing reagents, two laboratory, dehlorator and ammoniator, as well as utility structures (wardrobe, shower, sanitary unit, etc.). It is very important to correctly arrange the reagent and sand facilities, as well as reagent warehouses, in relation to the main structures.

A sanitary protection area is provided around the treatment facilities site.

On the general plan of the water treatment station, the location of the main structures, including clean water reservoirs, and a number of auxiliary structures, is given. The general plan has all the main paths and communications - roads, pipe lines.

Horizontal sumps are built semi-buried in the ground next to the filter station building. Vortex flapping chamber is structurally combined with horizontal sump. Fast filters are installed in the filter station building on the ground floor. Mixers are located in the same building on the second floor.