Industrial Wastewater Treatment Project Case of a Certain Oilfield

Project Overview

1. Project Name: Industrial Wastewater Treatment Project Case of a Certain Oilfield

2.  Wastewater type: Oilfield industrial wastewater

3. Processing water volume: 2000m ³/d

4. Characteristics of sewage:

The wastewater mainly consists of electric desalination drainage, crude oil tank cutting drainage, circulating water drainage, alkylation drainage, and acid-base neutralization water from the desalination station. Compared with other wastewater generated from crude oil processing, this wastewater has the characteristics of high surfactant content (caused by the use of demulsifiers), high oil concentration, high salt concentration, and high concentration of cyclic acids.

5. Difficulties in handling:

High COD, low BOD, high water concentration, high density, and high acid value.

The content of gum is high, belonging to the intermediate base oil of cyclohexane, and the processing difficulty is relatively high.

6. Sewage treatment process:

Common treatment methods for this wastewater include gravity separation, air flotation, electrocoagulation, adsorption, and biochemical methods. The sewage treatment process of this project is as follows:

Salt containing wastewater is first treated in an oil separation tank and then enters a regulating tank. In the regulating tank, there is a floating circulation oil collector to achieve the initial oil removal of sewage. The effluent from the regulating tank is pumped to the oil-water separator, where suspended solids and most of the floating oil are removed. After that, the wastewater flows automatically to the vortex concave air flotation device. At this stage, some emulsified oil and suspended solids are removed by adding polyaluminum chloride (PAC) and polyacrylamide (PAM) produced by YuXinHuan Water Treatment Materials Co., Ltd.

Afterwards, the sewage flows automatically to the dissolved air flotation device. Before entering the air flotation tank, add PAC and PAM produced by Yuxinhuan again. In the air flotation tank, dispersed oil and suspended solids combine with microbubbles to form an air flotation body, which is removed by scraping slag.

The air flotation effluent then enters the A/O biochemical tank. In the biochemical pool, the effects of aerobic, anaerobic, and facultative microorganisms are utilized to complete carbonization, nitrification, and denitrification reactions, effectively removing organic pollutants and ammonia nitrogen from wastewater.

The biochemical effluent enters the MBR membrane tank, and after MBR membrane mud water separation, it is lifted to the ozone oxidation tower and activated carbon tower. In the ozone oxidation tower, pollutants in wastewater are further oxidized by ozone; Subsequently, in the activated carbon tower, the adsorption effect of activated carbon is utilized to further purify the water quality. Finally, the wastewater flows into the monitoring tank and can be discharged or reused after adding sodium hypochlorite.

7.  Processing result:

After the above processing flow, the project has successfully achieved the sewage treatment and discharge standards stipulated in the “Comprehensive Wastewater Discharge Standard-GB31570-2015”, and has been operating stably until now. The polyaluminum chloride (PAC) and polyacrylamide (PAM) provided by YuXinHuan Water Treatment Materials Co., Ltd. play a key role in the sewage treatment process, ensuring the high efficiency and stability of the treatment effect.

Author: YuXinHuan®

WhatsApp：+86 19037152650

Email：xinhuan@xhwtm.com