CN103304103A - System for treating wastewater containing heavy oil - Google Patents

Abstract

The invention relates to a system for treating heavy oil-containing wastewater, which includes a pretreatment unit connected to each other, a coagulation air flotation unit, an oxidation and biochemical treatment filtration unit, and the pretreatment unit includes a grease separation tank, a regulating tank and clean water connected in sequence pool, the side of the clear water pool is connected to a slag pool, and the coagulation air flotation treatment unit includes a dosing device, an air flotation pool, a water outlet pool, and a control device connected to the air flotation pool and the water outlet pool, and the control device is connected to a dissolved air tank And the chemical tank, there is a strong oxidant in the oxidation and biochemical treatment filter unit, and the outlet water is connected to the original regeneration wastewater pool, that is, the biochemical pool or the activated carbon filter system. Compared with the prior art, the present invention utilizes the existing on-site oily sewage treatment equipment to transform and conduct on-site treatment tests. It is convenient to use and low in cost, and can well treat waste water containing heavy oil, which not only solves the problem that the waste water effluent is difficult to reach the standard problem, and reached the purpose of recycling.

Description

A system for treating waste water containing heavy oil

technical field

The invention relates to a wastewater treatment system, in particular to a system for treating heavy oil-containing wastewater.

Background technique

Wastewater produced by heavy oil from gas turbines has the characteristics of high CODcr, high oil content, high toxicity, and low B/C ratio, and belongs to difficult industrial wastewater. At present, the treatment methods of this kind of wastewater in China mainly adopt A/O and AA/O processes. These processes mainly use gravity separation and adsorption methods for oily substances. The removal rate of oily substances is only 20-30%, and the treatment effect is not good. It is very ideal, but it brings great difficulties to the subsequent biochemical treatment. Due to the fragile anti-shock load capacity of the biochemical system itself, the limitations of the traditional denitrification reaction mechanism, and the pressure brought by the pretreatment stage, the CODcr degradation of the system effluent is not complete, the conversion of ammonia nitrogen is not complete, and the effluent after treatment cannot reach GB8978-1996 "Comprehensive Wastewater Discharge Standard" secondary standard, that is, the main indicators are petroleum ≤ 10mg/L, CODcr ≤ 150mg/L, ammonia nitrogen ≤ 25mg/L.

Some enterprises adopt the method of increasing the dilution of heavy oil wastewater, so that the concentration of pollutants in the system is greatly reduced, and the effluent reaches the first-level discharge standard, that is, the main indicators are petroleum ≤ 10mg/L, CODcr ≤ 100mg/L, and ammonia nitrogen ≤ 15mg/L. However, a large amount of diluted wastewater increases the processing load of the biochemical station, virtually increases the energy consumption and cost of sewage treatment, makes the enterprise bear a huge economic burden, and violates the principle of clean production.

Contents of the invention

The object of the present invention is to provide an easy-to-use and low-cost system for treating heavy oil-containing wastewater in order to overcome the above-mentioned defects in the prior art.

The purpose of the present invention can be achieved through the following technical solutions:

A system for treating heavy oil-containing wastewater, including interconnected pretreatment units, coagulation air flotation units, oxidation and biochemical treatment filtration units,

The pretreatment unit includes a grease trap, a regulating tank and a clean water tank connected in sequence, and the side of the clean water tank is connected with a slag tank,

The coagulation air flotation unit includes a dosing device, an air flotation tank, a water outlet tank, and a control device connected to the air flotation tank and the water outlet tank. The control device is connected with a dissolved air tank and a medicament tank,

The oxidation and biochemical treatment filtration unit includes an oxidation pond, a biochemical treatment pond and a filtration unit.

The grease trap is in communication with the regenerated waste water pool containing waste water containing heavy oil.

Add Fupai compound coagulant to the air flotation tank.

Fupai compound coagulant is composed of inorganic coagulant and organic coagulant aid.

The inorganic coagulant includes polyaluminum chloride, polyferric sulfate, polysilicon aluminum chloride, polysilicon aluminum sulfate or polysilicon ferric sulfate, and the organic coagulant includes polyacrylamide or dimethyl propyl ammonium chloride.

The concentration of organic coagulant aid in the air flotation tank is 6-8mg/L.

The concentration of inorganic coagulant in the air flotation tank is 100-140mg/L.

The oxidation pool adopts strong oxidant for deep oxidation to further remove pollutants. A submersible mixer is installed at the bottom of the clean water pool to control the hydraulic retention time (HRT) in the pool to 8-9 hours to improve the biochemical properties of wastewater.

The biochemical treatment tank includes coagulation sedimentation, sludge concentration, filter press equipment and biochemical treatment equipment.

The filter unit includes a sand filter, activated carbon filter equipment, and fine filter equipment to filter wastewater.

Compared with the prior art, the present invention utilizes the existing on-site oily sewage treatment equipment to transform and carry out on-site treatment tests, which is convenient to use and low in cost, and can well treat wastewater containing heavy oil, which not only solves the problem of wastewater effluent reaching the standard problem, and achieved the purpose of recycling.

Description of drawings

Fig. 1 is a structural schematic diagram of the present invention.

In the figure, 1 is the regeneration waste water pool, 2 is the grease trap, 3 is the adjustment pool, 4 is the clear water pool, 5 is the slag pool, 6 is the air flotation pool, 7 is the outlet pool, 8 is the dissolved air tank, and 9 is the medicine tank , 10 is a control device, 11 is an oxidation and biochemical treatment filter unit.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example

A system for treating heavy oil-containing wastewater, its structure is shown in Figure 1, including interconnected pretreatment units, biochemical treatment pools and filtration units. The pretreatment unit includes a grease trap 2 , a regulating tank 3 and a clean water tank 4 connected in sequence, and a slag tank 5 is also connected to the side of the clean water tank 4 . The grease trap 2 communicates with the regenerated waste water pool 1 containing heavy oil containing waste water. Fupai compound coagulant can be added in the adjustment tank 3. Inorganic coagulants that can be used include polyaluminum chloride, polyferric sulfate, polysilicon aluminum chloride, polysilicon aluminum sulfate or polysilicon ferric sulfate, and organic coagulants include polyacrylamide, dimethyl propyl ammonium chloride . A submersible mixer is installed at the bottom of the clear water pool, and the hydraulic retention time (HRT) in the pool is controlled to be 8-9 hours, which is used to improve the oxidation and biochemical properties of the wastewater. The coagulation air flotation unit includes an air flotation tank 6 , a water outlet tank 7 , and a control device 10 connected with the air flotation tank 6 and the water outlet tank 7 , and the control device 10 is connected with a dissolved air tank 8 and a medicine tank 9 . The oxidation and biochemical treatment filtration unit 11 includes an oxidation treatment and biochemical tank. For example, the oxidation and biochemical treatment filter unit 11 includes coagulation sedimentation, sludge concentration, filter press equipment, sand filter tank, activated carbon filter equipment, and fine filter equipment to filter wastewater.

The results of the addition of Fupai compound coagulant to wastewater treatment are shown in the table below.

Table 1 The influence of the dosage of Fupai compound coagulant on the treatment effect

Claims (9)

1. a system that processes containing heavy oil waste water is characterized in that, this system comprises pretreatment unit, coagulation air-float unit, oxidation and the biochemical treatment filtering unit of mutual UNICOM,

Described pretreatment unit comprises oil trap, equalizing tank and the clean water basin that connect successively, and described clean water basin sidepiece is connected with slag bath,

Described coagulation air-float unit comprises chemicals dosing plant, air flotation pool, outlet sump and the control device that is connected with air flotation pool, outlet sump, and this control device is connected with dissolving and pharmacy jar,

Described oxidation and biochemical treatment filtering unit comprise oxidation pond, biochemical treatment tank and filtering unit.

2. a kind of system that processes containing heavy oil waste water according to claim 1 is characterized in that, described oil trap with the regenerated pond UNICOM that contains heavy oil waste water is housed.

3. a kind of system that processes containing heavy oil waste water according to claim 1 is characterized in that, adds the agent of Fupai compounding coagulation in the described air flotation pool.

4. a kind of system that processes containing heavy oil waste water according to claim 1 is characterized in that, the agent of described Fupai compounding coagulation is by inorganic coagulant and organic coagulant aids is composite forms,

Described inorganic coagulant comprises poly aluminium chloride, polyiron sulfate, poly-silicon aluminum chloride, polymeric aluminum sulfate silicate or ferric sulfate of polymerized silica, and described organic coagulant aids comprises polyacrylamide or dimethyl propylene ammonium chloride.

5. a kind of system that processes containing heavy oil waste water according to claim 4 is characterized in that, the concentration of described organic coagulant aids in air flotation pool is 6-8mg/L.

6. a kind of system that processes containing heavy oil waste water according to claim 4 is characterized in that, the concentration of described inorganic coagulant in air flotation pool is 100-140mg/L.

7. a kind of system that processes containing heavy oil waste water according to claim 1, it is characterized in that, oxidation pond adopts the strong oxidizer deep oxidation, further remove pollutent, the bottom of clean water basin is provided with diving mixer, the control pool inner water power residence time (HRT) is 8～9 hours, improves the biochemical property of waste water.

8. a kind of system that processes containing heavy oil waste water according to claim 1 is characterized in that, described biochemical treatment tank comprises that coagulating sedimentation, mud are concentrated, filtering equipment and biochemical treatment apparatus.

9. a kind of system that processes containing heavy oil waste water according to claim 1 is characterized in that, described filtering unit comprises sand filter, activated carbon filtration equipment, smart filter equipment, and waste water is carried out filtration treatment.

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