Treatment system for organic sewage in contaminated site remediation process

Abstract

The invention provides a treatment system for organic sewage in a contaminated site remediation process. The treatment system comprises a demulsification oil separation tank, a regulation tank, an advanced oxidation tank, a coagulative precipitation tank and an activated carbon tank; the demulsification oil separation tank is a pretreatment unit, and if the organic sewage contains TPH or NAPL phase pollutants, the organic sewage enters the demulsification oil separation tank and is pretreated; the regulation tank is located at the downstream of the demulsification oil separation tank, and if the organic sewage does not contain TPH or NAPL phase pollutants, the organic sewage directly enters the regulation tank and is treated; the advanced oxidation tank is located at the downstream of theregulating tank, and refractory organic matters in the organic sewage are treated in a targeted manner by using an advanced oxidation method; the coagulative precipitation tank is positioned at the downstream of the advanced oxidation tank and is provided with a coagulation area and a precipitation area; the activated carbon tank is positioned at the downstream of the coagulative precipitation tank and is used for deeply treating the effluent of the coagulative precipitation tank to make the effluent discharged or recycled after reaching standards; and a sludge thickening tank is used for collecting, thickening and outwards transporting or recycling dross and sludge.

Description

technical field [0001] The invention belongs to the technical field of remediation of contaminated sites, and relates to a treatment system for organic sewage, in particular to a treatment system for organic sewage used in the process of remediation of contaminated sites. Background technique [0002] "Contaminated site" refers to a spatial area that is harmful to human health and the environment or has potential risks due to accumulation, storage, treatment, disposal or other means of carrying harmful substances. Carriers of hazardous substances include site soil, site groundwater, site surface water, site residual waste pollutants such as production equipment and buildings, etc. When the land use function of the polluted site is transformed and reused for secondary development, restoration is urgently needed to ensure the safety of the living environment and the ecological environment. The restoration of organically polluted sites has gradually become a hot spot in my coun...

AI Technical Summary

Problems solved by technology

The problems of this sewage treatment process include: the sewage treatment process is a conventional demulsification-secondary air flotation treatment, and no advanced treatment unit is set up. The disadvantage is that the air flotation will blow off the volatile organic compounds in the organic sewage. Cause secondary pollution. On the other hand, there is no advanced oxidation unit or biochemical treatment unit, and only relying on the air flotation unit has limited processing capacity and cannot achieve higher effluent water quality. It can only transfer organic pollutants and cannot eliminate organic hazards.

However, there are some deficiencies in this method, mainly including: 1. No demulsification and oil separation pre-treatment unit is installed, and the treatment effect on sewage containing TPH or NAPL phase is limited

2. Only Fenton (Fenton) oxidation unit is used. According to the literature "Comparative Study on the Removal of PAHs in Contaminated Soil by Different Oxidation Systems" and "Remediation Effects of PAHs in Coking Contaminated Sites with Different Chemical Oxidants", Fenton reagent Or Fenton-like reagents are not as effective in treating PAHs as potassium permanganate and sodium persulfate, so the advanced oxidation unit should adopt a variety of oxidation technologies to improve the processing efficiency

The deficiencies of this wastewater treatment device include: 1. The thermal desorption wastewater directly enters the gravity oil separation sedimentation adjustment tank, which can remove the TPH or NAPL phase in the wastewater, but if the wastewater does not contain pollutants that need to be removed by oil separation, then No need to go directly to this unit

2. The air flotation unit is easy to blow off the VOCs in the wastewater, which may cause secondary pollution

3. The quartz sand filter is used, but the filter backwashing system is not installed. After long-term operation, the filter may be blocked and the treatment efficiency will be reduced.

4. For the scum or sludge produced by sedimentation tanks, air flotation tanks, chemical oxidation tanks and other units, no collection and discharge units are designed

[0008] To sum up, most of the treatment devices or systems for sewage generated during site remediation reported so far are aimed at the sewage produced by a single site remediation process, such as in-situ / ex-situ thermal desorption process sewage, with a narrow application range and existing technologies There are deficiencies

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