30m3h oilfield sewage treatment

1.1 Project Overview

1.1.1 Project Name, Location
Project Name: Oilfield Wastewater Treatment Project
Scale: 30m3/h

1.1.2 Project Overview
Oilfield sewage mainly contains pollutants such as oil, sediment and heavy metal ions, among which sediment accounts for the main body. Drilling wastewater has large fluctuations in water volume, high COD concentration and instability, and high SS. In the past, many drilling units used recirculation and large pit evaporation methods, which seriously polluted the local environment, especially the recharge method, which had a serious impact on local agricultural irrigation and its water system. If it is not treated in time, it will seriously pollute the environment and affect people's physical and mental health.
Our company is entrusted by the drilling unit to participate in the engineering design of drilling wastewater for your company's leadership decision.

1.2.3 Design water quality
Designed water volume: according to customer data, the water volume is 30m3/h
Water quality: According to the water quality data provided by customers, refer to the water quality characteristics of the same industry as a reference to determine the design water quality as follows:
Influent water quality (units in the table are in mg/L, except PH)

1.2.4 Sewage discharge standards
National emission standards (in the table, 1mg/L, except PH) emissions

Chapter III Wastewater Treatment System Process

3.1 Analysis of wastewater properties and process route determination:
Oilfield sewage contains oil, sediment, heavy metal ions and so on.
1. The COD concentration is high and unstable, mainly caused by oil pollution;
2, containing a large amount of suspended solids, mainly formed by sediment;
3. The sewage SS is high, mainly caused by sediment and sludge;
4, containing a certain amount of heavy metal ions, mainly by adding inorganic treatment agent complex acid salt introduced cr6 + and so on. There are also pb2+ and cd2+.

Sewage treatment process:
According to the characteristics of the wastewater and the requirements for the treatment of the effluent, the wastewater treatment process can be carried out by air flotation + filtration. In the characteristics of wastewater discharge, the properties of wastewater, the following processes are currently being developed.

3.2 Introduction to wastewater process:
The waste water is treated by the air flotation machine to dispose of the oil and sediment, and the water is removed by the multi-media filter to remove the fine SS and the residual oil, and then the activated carbon filter strongly adsorbs and filters the oil and other undesirable substances in the water. The main pollutants in mine sewage are oil and sediment. As long as the oil and sediment are disposed of, the water quality will be restored and the discharge will be completed.
The sludge and oil generated by the air flotation machine enter the sludge pool for regular treatment. Customers can choose sludge drying or dewatering treatment of the stack filter.
Sludge drying is to dry the sludge in a site. The advantage is that the equipment is invested. The shortcoming is that the time is long and the site is large. The sludge can be directly transported away after being treated by dewatering. (Customer can choose)

3.3 Pollutant indicator removal measures and removal rate prediction:
The main pollutant removal measures in this program are as follows:
Removal of COD/BOD: The purpose of removing COD/BOD mainly by adsorption of air flotation device and filter.
Removal of SS: The purpose of removing SS is mainly achieved by an air flotation device and a filter.
Oil pollution: flotation of the air flotation machine and filtration and adsorption removal of the filter.
Other indicators: With the removal of COD and SS, oil pollution, the remaining indicators are also greatly reduced.

Chapter 4: Equipment Selection and Function
According to the characteristics of wastewater, in accordance with economic principles, it is determined to use a 30m3 / h air floating filter integrated machine. The air flotation filter integrated machine includes a dissolved air flotation machine and a multi-media filter and an activated carbon filter.

4.1 Air Floater:
The dissolved air flotation machine utilizes clean water or partially treated return water, and the air is sucked and mixed by the microbubble generator to form dissolved gas water, which is released under reduced pressure in the air floating tank, and the air dissolved in the water is formed by bubbles of 20-30 μm. Precipitation, with high surface area adsorption capacity, can be better removed for suspensions of different concentrations of sewage, part of the clean water after treatment (design index is 20-40%, usually 30%), air-floating circulation working pump The pressurized water-insoluble gas tank is mixed with air, and the air is dissolved in water, and the dissolved gas efficiency at this time reaches 80% or more. The air dissolved in the water is released from the water to form microbubbles having a particle diameter of 20-50 μm, and the microbubbles are combined with the suspended matter in the sewage, so that the specific gravity of the suspended matter in the sewage becomes small until it floats on the surface of the water body; The slag is then removed by a chain scraper installed on the air floatation tank to achieve the treatment effect.

JXW series dissolved air flotation machine is mainly used for solid-liquid or liquid-liquid separation. A large amount of fine bubbles are generated in the water by the dissolved gas and the release system, so that it adheres to the solid or liquid particles whose density is close to that of the water, causing the overall density to be lower than that of the water, and by buoyancy to rise to the surface of the water, thereby Achieve the purpose of solid-liquid or liquid-liquid helium.

The role of dissolved air flotation machine in the treatment of oily wastewater is very obvious. By adding 2-3 kinds of flocculants, the oil and the suspended matter in the sewage are flocculated, and under the action of dissolved air release, the water surface is installed on the upper part of the scraping residue. The machine scraped away, and the mine sewage became clear at this time, but it also contained some small SS and residual oil.

4.2 Filter:
Filtration is one of the indispensable means in the sewage treatment process, especially the discharge of pollutants after sewage treatment, used to intercept impurities and fine SS in the water to purify water, save water or protect the environment.
The ordinary mesh filter has a small amount of dirt, is easily blocked by dirt, and has complicated cleaning work. The device must be disassembled to clean the filter part, and the state of the filter cannot be monitored, and is affected by human factors. Reduce the automation of the entire system.

Although the membrane type device has a powerful purification effect, many companies are discouraged because of its high cost, high cost of replacing the filter element of the membrane, complicated operation, and complicated backwashing system.
By using the multi-media and activated carbon filter adsorption and decolorization ability in the feed water, different types of multi-media and activated carbon are loaded to remove residual chlorine, organic matter, bacteria, color, odor, oil and the like in the water. In particular, loading activated carbon with different properties can achieve the corresponding treatment target. The water contains suspended matter condensed sheet, which is a kind of adhesive colloidal particles which cannot be removed by simple precipitation, air floatation, etc., and the activated carbon filter is used to separate and filter the water body. The effluent turbidity is generally below 5mg/I, which is in line with national first-class emission standards. It also has a good removal effect on suspended solids, solids, heavy metal ions, etc. in industrial wastewater.

This product has two kinds of filter material and activated carbon. The activated carbon filter is used in the deep treatment of water. It can remove the color, odor and micro particles in the water. As the filter material, the activated carbon should be selected according to the water demand. Granular activated carbon.

Features:

1) Compact structure and easy operation.
2) Cleaning is simple and does not incur additional costs.
3) The filtering area is large, the amount of dirt is high, and the adsorption is good.
4) The temperature of the water flowing through the medium is not limited.
5) The filter material has a long service life, strong maintainability, and easy installation and disassembly.
6) Small footprint and convenient transportation.