CN114906974A - Cabin washing wastewater treatment process - Google Patents

Abstract

The invention provides a tank washing wastewater treatment process, which comprises the following steps: step S1: conveying the port washing wastewater to a regulating reservoir, and adopting a plurality of regulating reservoirs according to the insoluble wastewater and the easily soluble wastewater; step S2: entering a pretreatment process; step S3: entering an advanced oxidation process; step S4: entering an anaerobic process; step S5: entering an aerobic process; step S6: treating in an ozone aeration biological filter; step S7: the wastewater after the treatment reaches the standard and is discharged. The invention is suitable for the combined process of different chemical wastewater, and achieves the aims of no secondary pollution, standard-reaching discharge of wastewater, economy and high-efficiency treatment.

Description

Cabin washing wastewater treatment process

Technical Field

The invention mainly relates to the field of wastewater treatment, in particular to a tank washing wastewater treatment process.

Background

According to relevant regulations, the water for washing the ship tanks must be concentrated in the sump oil water tank of the ship, and the system discharges according to the specified requirements; or concentrated discharge to the terminal sump oil water receiving system on demand at a conditional port and prohibit anyone from discharging the tank wash directly outboard untreated.

The port chemical wastewater refers to the wastewater (such as tank washing, etc.) generated when a bulk liquid chemical transport ship needs to be cleaned or replaced with cargo. The main pollutants in the water are the residual matters of the swept cabin and the washing tank after unloading. The sewage is considered as a kind of wastewater with higher treatment difficulty because the sewage contains chemical substances which are difficult to biologically treat, such as benzene substances, halogenated substances and cleaning agents for cleaning cabins, and because the quantity and the concentration of the wastewater are changeful and random due to complex transportation objects, various pollutants and the like.

The chemical waste water is stored in dock conveying tank and then fed into waste water treating apparatus, and the waste water treatment is mainly one combined physical and chemical process including air floating, biological film, oxidation ditch, etc. according to different water quality. However, the treatment of wharf wastewater in China is still in a starting stage, only large ports are provided with wastewater treatment stations, and the treatment range of port chemical wastewater must be greatly promoted according to the requirements of sustainable development, so that the shipping is safer, and the ocean is cleaner.

The existing treatment process is single, only can meet the treatment requirement of specific water quality, and is difficult to popularize, and most of the existing wharf sewage treatment systems cannot adapt to the characteristics of large water quality change and strong toxicity of chemical tank washing water, so that the wharf sewage treatment systems cannot stably and normally operate.

Disclosure of Invention

Aiming at the problems and defects of difficult degradation and complex water quality in the prior art, the invention provides a tank washing wastewater treatment process, which comprises the following steps:

step S1: conveying the port cabin washing wastewater to a regulating tank, and adopting a plurality of regulating tanks according to the insoluble wastewater and the easily soluble wastewater, wherein the residence time in the regulating tanks is 1-3 days, and the water temperature in the regulating tanks is 10-15 ℃;

step S2: the wastewater after S1 enters a pretreatment process, wherein the pretreatment process comprises a primary sedimentation tank, and the hydraulic retention time is 0.1-1 day;

step S3: the indissolvable wastewater which passes through S2 enters an advanced oxidation process, the hydraulic retention time is 1-12h, under the action of a catalyst, hydrogen peroxide is used as an oxidant, and the ratio of the hydrogen peroxide to COD is 1:1-3: 1;

step S4: mixing the insoluble wastewater and the rest soluble wastewater obtained in the step S3, and allowing the mixture to enter an anaerobic process, wherein the hydraulic retention time is 0.5-3 days;

step S5: the mixed liquid of the waste water obtained in the step S4 enters an aerobic process, and the hydraulic retention time is 6-24 h;

step S6: the effluent of the mixed liquid obtained in the step S5 enters an ozone aeration biological filter for treatment, an ozone aeration biological filter integrated device consists of an ozone oxidation system and an aeration biological filter, the effluent enters the ozone aeration biological filter integrated device, ozone is mixed with wastewater in a pipeline adding mode, and the adding amount of the ozone is 100 plus 500 mg/L; carrying out ozone oxidation on the wastewater, and then carrying out biochemical treatment in an aeration biological filter, wherein the hydraulic retention time is 2-12 h;

step S7: the wastewater after the treatment reaches the standard and is discharged.

Preferably, the anaerobic process in step S4 is an EGSB process.

Preferably, the aerobic process in step S5 employs an immersed membrane bioreactor, the membrane bioreactor employs an immersed hollow fiber membrane, and the biochemical section of the membrane bioreactor employs an anoxic-aerobic process.

Preferably, the wastewater discharge standard of step S7 is that COD is not more than 50 mg/L.

Preferably, the filler of the biological aerated filter in the step S6 uses ceramsite as a carrier.

Preferably, the poorly soluble wastewater comprises DOP, o-xylene, styrene, 2-EH, and the readily soluble wastewater comprises acetic acid and methanol.

Preferably, the original COD of the harbor tank-washing wastewater in the step S1 is 10000-30000mg/L, the oil content is 80-200mg/L, and the SS is 50-100 mg/L.

The invention has the beneficial effects that: the process is mature, the treatment effect is stable, the treatment effect on the wastewater is good, the wastewater treatment cost is low, and after the advanced treatment of the combined process, the effluent of the cabin-washing chemical wastewater can be directly discharged up to the standard or can be used as the inlet water of reuse water in the future.

Detailed Description

In order to make the technical solutions of the present invention better understood and make the above features, objects, and advantages of the present invention more comprehensible, the present invention is further described with reference to the following examples. The examples are intended to illustrate the invention only and are not intended to limit the scope of the invention.

The invention comprises the following procedures:

step S1: conveying the port tank washing wastewater to a regulating tank, wherein the original COD of the port tank washing wastewater is 10000-30000mg/L, the oil content is 80-200mg/L, and the SS is 50-100mg/L, and adopting a plurality of regulating tanks according to the insoluble wastewater and the easily soluble wastewater, wherein the insoluble wastewater comprises DOP, o-xylene, styrene and 2-EH, the easily soluble wastewater comprises acetic acid and methanol, the residence time in the regulating tanks is 1-3 days, and the water temperature in the regulating tanks is 10-15 ℃;

step S2: the wastewater after S1 enters a pretreatment process, wherein the pretreatment process comprises a primary sedimentation tank, and the hydraulic retention time is 0.1-1 day;

step S3: the indissolvable wastewater which passes through S2 enters an advanced oxidation process, the hydraulic retention time is 1-12h, under the action of a catalyst, hydrogen peroxide is used as an oxidant, and the ratio of the hydrogen peroxide to COD is 1:1-3: 1;

step S4: mixing the indissolvable wastewater subjected to the step S3 with the rest easily-soluble wastewater to enter an anaerobic process, wherein the anaerobic process adopts an EGSB (expanded granular sludge bed) process for treatment, and the hydraulic retention time is 0.5-3 days;

step S5: allowing the wastewater mixed liquor obtained in the step S4 to enter an aerobic process, wherein the hydraulic retention time is 6-24 h, the aerobic process adopts an immersed membrane bioreactor, the immersed hollow fiber membrane is adopted as the membrane bioreactor, and the anoxic-aerobic process is adopted as a biochemical section of the membrane bioreactor;

step S6: the effluent of the mixed liquid obtained in the step S5 enters an ozone aeration biological filter for treatment, an ozone aeration biological filter integrated device consists of an ozone oxidation system and an aeration biological filter, the effluent enters the ozone aeration biological filter integrated device, ozone is mixed with wastewater in a pipeline adding mode, and the adding amount of the ozone is 100 plus 500 mg/L; carrying out ozone oxidation on the wastewater, and then carrying out biochemical treatment in an aeration biological filter, wherein the filler of the aeration biological filter takes ceramsite as a carrier, and the hydraulic retention time is 2-12 h;

step S7: the wastewater after the treatment reaches the standard and is discharged, and the discharge standard of the wastewater is that COD is not more than 50 mg/L.

The specific implementation mode is as follows:

the water amount of the tank washing wastewater of the port per month is about 60t, the acetic acid pollutant wastewater is 45 tons/day, the DOP, o-xylene, styrene and 2-EH refractory organic wastewater is 15 tons/day, the COD (chemical oxygen demand) of the inlet water of the refractory organic wastewater is 20000mg/L, the highest concentration of the refractory organic wastewater is 12000, the oil content is 300mg/L, and the SS (suspended solids) is 100 mg/L. Adjusting the reaction temperature of the pool: 15 ℃;

(1) treating in a regulating reservoir: the device comprises two regulating ponds, wherein the two regulating ponds are respectively used for regulating the waste water containing easily degradable organic matters and difficultly degradable organic matters, and the waste water from the cabin washing of the port stays in the regulating ponds for 1 d;

(2) the indissolvable wastewater comprises the following components: DOP, o-xylene, styrene, 2-EH, easily soluble waste water including acetic acid, methanol, etc.;

(3) the insoluble wastewater passes through an advanced oxidation process, the concentration of a catalyst is 5000mg/L, the dosage of hydrogen peroxide is 15000mg/L, the reaction time is 8 hours, and the COD of the insoluble wastewater after oxidation is 1440 mg/L;

(4) and (3) introducing the indissolvable wastewater mixed liquor into an anaerobic and aerobic membrane bioreactor system, wherein PVDF immersed ultrafiltration is adopted as a membrane, and the retention time is 24 hours.

(5) Ozone is mixed with the wastewater in a pipeline adding mode, and the adding amount of the ozone is 300 mg/L; and the wastewater is subjected to ozone oxidation and then biochemical treatment in an aeration biological filter, and the retention time of the ozone oxidation water power is 1.5 h.

(6) The wastewater after ozone oxidation enters an aeration biological filter, the filler of the aeration biological filter takes ceramsite as a carrier, and the retention time is as follows: 4 hours;

(7) the COD of the finally obtained wastewater is less than 50mg/L and reaches the national first-level discharge standard.

Compared with the original treatment mode, the cleaning wastewater is usually discharged to the open sea or discharged as the dangerous waste liquid by external pulling through long-distance transmission, pollutants are not treated in the first mode, the influence of the pollutants on the natural environment is greatly increased, and although the pollutants are treated in the second mode, the cost of the dangerous waste liquid by external pulling is high, and the economical efficiency is poor; in the past, even if partial areas are treated, a mixed treatment mode is still adopted, and pollutants are not classified, so that the treatment efficiency of the pollutants is influenced. The method is solved in the process. And meets the treatment requirement of the first grade A, and meets the requirements of discharge and reuse.

The above-described embodiments are merely illustrative of the principles and utilities of the present patent application and are not intended to limit the present patent application. Those skilled in the art can modify and/or change the above-described embodiments without departing from the spirit and scope of the present application. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical concepts disclosed in the present application shall be covered by the claims of this patent application.

Claims (7)

1. A cabin washing wastewater treatment process is characterized by comprising the following steps:

step S1: conveying the port cabin washing wastewater to a regulating tank, and adopting a plurality of regulating tanks according to the insoluble wastewater and the easily soluble wastewater, wherein the residence time in the regulating tanks is 1-3 days, and the water temperature in the regulating tanks is 10-15 ℃;

step S2: the wastewater after S1 enters a pretreatment process, wherein the pretreatment process comprises a primary sedimentation tank, and the hydraulic retention time is 0.1-1 day;

step S3: the indissolvable wastewater which passes through S2 enters an advanced oxidation process, the hydraulic retention time is 1-12h, under the action of a catalyst, hydrogen peroxide is used as an oxidant, and the ratio of hydrogen peroxide to COD is 1:1-3: 1;

step S4: mixing the insoluble wastewater and the rest soluble wastewater obtained in the step S3, and allowing the mixture to enter an anaerobic process, wherein the hydraulic retention time is 0.5-3 days;

step S5: the mixed liquid of the waste water obtained in the step S4 enters an aerobic process, and the hydraulic retention time is 6-24 h;

step S6: the effluent water of the mixed liquid obtained in the step S5 enters an ozone aeration biological filter for treatment, an ozone aeration biological filter integrated device consists of an ozone oxidation system and an aeration biological filter, the effluent water enters the ozone aeration biological filter integrated device, ozone is mixed with wastewater in a pipeline adding mode, and the adding amount of the ozone is 100 plus materials of 500 mg/L; carrying out ozone oxidation on the wastewater, and then carrying out biochemical treatment in an aeration biological filter, wherein the hydraulic retention time is 2-12 h;

step S7: the wastewater after the treatment reaches the standard and is discharged.

2. The tank-washing wastewater treatment process according to claim 1, characterized in that: the anaerobic process in step S4 is an EGSB process.

3. The tank-washing wastewater treatment process according to claim 2, characterized in that: the aerobic process in the step S5 adopts an immersed membrane bioreactor, the membrane bioreactor adopts an immersed hollow fiber membrane, and the biochemical section of the membrane bioreactor adopts an anoxic-aerobic process.

4. The tank-washing wastewater treatment process according to claim 3, characterized in that: the discharge standard of the wastewater of the step S7 is that COD is not more than 50 mg/L.

5. The tank-washing wastewater treatment process according to claim 4, characterized in that: and the filler of the biological aerated filter in the step S6 takes ceramsite as a carrier.

6. The tank-washing wastewater treatment process according to claim 5, characterized in that: the insoluble waste water comprises DOP, o-xylene, styrene and 2-EH, and the soluble waste water comprises acetic acid and methanol.

7. The tank-washing wastewater treatment process according to claim 6, characterized in that: the original COD of the harbor washing tank wastewater in the step S1 is 10000-30000mg/L, the oil content is 80-200mg/L, and the SS is 50-100 mg/L.