AU2020101212A4

AU2020101212A4 - A water treatment system for port chemical tank washings based on ultrasonic enhanced micro electrolysis

Info

Publication number: AU2020101212A4
Application number: AU2020101212A
Authority: AU
Inventors: Jianna Jia; Shitao Peng
Original assignee: Tianjin Research Institute for Water Transport Engineering MOT
Current assignee: Tianjin Research Institute for Water Transport Engineering MOT
Priority date: 2019-08-28
Filing date: 2020-07-01
Publication date: 2020-08-06
Anticipated expiration: 2028-07-01
Also published as: CN211035324U

Abstract

The invention discloses a port chemical tank washings treatment system based on ultrasonic enhanced micro electrolysis, which comprises a regulating tank, a reaction tank and an ultrasonic generator. The regulating tank is an open tank which is connected with the reaction tank. The reaction tank is a closed cylindrical tank separated into an upper micro electric reaction area and a lower aeration mixing area by a built-in supporting layer. The supporting layer is a cylindrical porous structure formed by the adhesion of crushed stones. The micro electric reaction area is filled with a micro electric reaction layer, which is composed of a mixture of activated carbon particles and iron chips. And the ultrasonic generator can connect to the top of the micro electric reaction layer through an ultrasonic transducer. The system has a good treatment effect on all kinds of high concentration refractory organics contained in the chemical tank washings. It can significantly improve the biodegradability and effectively solve the problems which the traditional treatment process can't adapt to, such as the large fluctuation of water quality and the complexity of pollutant composition. In addition, the system equipment has advantages in simple structure, strong durability, long service life, convenient operation and low processing cost. 1/1 306 305 304 FIG. 1

Description

1/1

306 305

304

FIG. 1

A Water Treatment System for Port Chemical Tank Washings Based on Ultrasonic Enhanced Micro Electrolysis

TECHNICAL FIELD The invention relates to the technical field of sewage treatment, in particular to a water treatment system for port chemical tank washings based on ultrasonic enhanced micro electrolysis.

BACKGROUND Bulk chemical transportation at Chinese ports began in the early 1980s. At present, the volume of bulk chemical transportation in Shanghai, Ningbo, Dalian, Tianjin, Xiamen, Guangzhou and other ports has increased significantly, among which more than 60

% of the bulk chemical transportation in China is undertaken by Shanghai, Ningbo, Dalian and Tianjin port. The bulk chemicals mainly handled in Shanghai Port include sulfuric acid, oxalic acid, benzene, toluene, p-xylene, styrene, acetate, animal and vegetable oil, etc. Tianjin Port mainly handles toluene, xylene, ethyl acrylate and other chemicals. At the same time, according to the statistics released by the Ministry of transport, the transportation volume of dangerous chemicals ports in the Yangtze River trunk line will reach 220 million tons / year in 2020, and the output of chemical tank washing wastewater will exceed 20000 tons / year. The following characteristics of chemical tank washings greatly increased the difficulty of treatment: (1) There are many kinds of organics. At present, there are about 50 kinds of chemicals which are difficult to degrade in the transportation of domestic ports. (2) The concentration of pollutants is high. The concentration of COD pollutants in the tank washing wastewater is more than 1000mg/L. (3) The water quality has great randomness. The variety of bulk chemical transportation changes greatly, therefore, the water quality has a great randomness, which increased the difficulty of tank washings treatment. (4) The biodegradability of tank washings is low. There are a lot of refractory organics in chemical tank washings. According to the investigation, the biodegradability (BOD 5/ COD) of chemical tank washings is only 0.1 - 0.2, so it can't be effectively removed by conventional biological treatment process. As a contracting party to MARPOL 73/78, China has formulated "Regulations for the prevention of marine pollution by ships" on the basis of Annex II of MARPOL 73/78 in order to effectively control the pollution of port oil sewage and liquid substances of harmful chemicals in bulk. Accordingly, an economic and effective chemical wastewater treatment method is urgently needed to improve the quality of port water and ecological environment, and promote the construction of a national green port. Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.

SUMMARY In certain embodiments, the objective of the invention is to provide water treatment system for port chemical tank washings based on ultrasonic enhanced micro electrolysis so as to realize the chain breaking of macromolecular organic pollutants, and improves the biodegradability of wastewater, and effectively reduces the load and cost of subsequent biological treatment. It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative. The invention solves the technical problem by adopting the following technical solution: A water treatment system for port chemical tank washings based on ultrasonic enhanced micro electrolysis, which includes a regulating tank, a reaction tank and an ultrasonic generator; wherein the regulating tank is a tank with a top opening, and a first water inlet pipe is arranged on an upper portion of a side wall, and a first water outlet pipe is arranged at an opposing lower portion of a side wall; wherein the reaction tank is a closed cylindrical tank, in which a supporting layer is arranged, so that an inner cavity of the reaction tank is divided into a micro electrolytic reaction area at an upper part and an aeration mixing area at a lower part, and the supporting layer, which is fixed on an inner wall of the reaction tank, is a cylindrical porous structure formed by adhesion of a plurality of crushed stones, and a lower part of the micro electrolytic reaction area is filled with a micro electrolytic reaction layer which is composed of a mixture of activated carbon particles and iron chips; a second water inlet pipe is arranged at a lower portion of the reaction tank, and an air inlet pipe is arranged on a side wall of the aeration mixing area; a second water outlet pipe is on a side wall of the micro electrolytic mixing area of the reaction tank, and an ultrasonic transducer is arranged on top of the reaction tank, wherein the ultrasonic transducer is connected with an ultrasonic generator, and the ultrasonic transducer extends to the top of the micro electrolysis reaction layer; and wherein the first water outlet pipe is connected with the second water inlet pipe through a connecting pipe, and a lifting pump and a first liquid flow regulating valve are arranged to the connecting pipe; and wherein the outer end port of the air inlet pipe is connected with an air pump through a pipeline. For preference, the frequency range of the ultrasonic generator is 20~40 Hz. For preference, the volume of the micro electric reaction area accounts for 4/5 of the volume of the inner cavity of the tank, and the height of the supporting layer is 0.1~0.3m. For preference, the volume of the micro electrolysis reaction layer accounts for 3/5~4/5 of the volume of the micro electrolysis reaction area. For preference, the micro electrolysis reaction layer is formed by a mixture of iron chips and activated carbon particles with a weight ratio of 3:1~4:1. Preferably the total volume of it accounts for 3 / 5 of the volume of the micro electric reaction area. Also preferably the particle size range of iron chips is 2.0~5.0 mm, and that of activated carbon particles is 1.5-3.0 mm. For preference, the flow regulating range of the first liquid flow regulating valve meets the requirement that the retention time of wastewater in the reaction tank is 1-1.5 h. Preferably, at least one lifting pimp is arranged in the regulating tank. Preferably, a second liquid flow regulating valve is arranged on the second water outlet pipe, and an air flow regulating valve is arranged on the air inlet pipe. Compared with the available technologies, the beneficial effect of the port chemical tank washings treatment system based on ultrasonic enhanced micro electrolysis is as follows. Compared with the prior art, the Water Treatment System for Port Chemical Tank Washings Based on Ultrasonic Enhanced Micro Electrolysis has the following beneficial effects: (1) The system has a good effect on the treatment of all kinds of high concentration refractory organics contained in chemical tank washings; It can significantly improve the biodegradability (BOD/COD) and effectively solve the problems of traditional treatment processes, such as being unable to adapt to the large fluctuation of water quality and the complexity of pollutant composition; (2) The system equipment has advantages in simple structure, strong durability, long service life and convenient operation and maintenance; The system does not need to change the activated carbon material, as long as the iron chips are added every half a year; (3) The system uses shavings or scrap iron, which can effectively reduce the cost of treatment and realize the resource utilization of industrial waste residue.

DESCRIPTION OF DRAWINGS Fig.1 is the structural diagram of the utility model of the port chemical tank washings treatment system based on ultrasonic enhanced micro electrolysis.

DETAILED DESCRIPTION The invention is further expounded as follows in combination with the accompanying drawings and embodiments, but is not limited to the following embodiments. Besides, unless otherwise explicitly specified or defined, the terms such as "connection" and "connected" should be understood broadly in the description of this embodiment.

As shown in Fig. 1, a water treatment system for port chemical tank washings based on ultrasonic enhanced micro electrolysis includes regulating tank 1, reaction tank 3 and ultrasonic generator 6. The regulating tank 1 is a tank with a top opening which equipped with a lifting pump. The first water inlet pipe 101 is arranged on the side wall close to the top, and the first water outlet pipe 102 is arranged on the side wall near the bottom of the pool, and the two pipes are respectively arranged on the opposite side wall of the regulating tank 1. The first water inlet pipe 101 is connected with the water outlet pipe of the ship's tank washings storage tank through the connecting pipe, so that the pipeline will first lead the ship's washing water into the regulating tank 1, which is equipped with a submersible pump 1. The function of the regulating tank is to control the treatment speed of the tank washing water, and discharge the tank washing water in the regulating tank 1 to the reaction tank 3 at a stable rate according to the preset treatment capacity of the reaction tank 3, so as to achieve the best treatment efficiency of the reaction tank 3.

The reaction tank 3 is a closed cylindrical tank, in which a supporting layer 301 is arranged, so that the inner cavity of the tank is divided into a micro electric reaction area at the upper part and an aeration mixing area at the lower part. Specifically, the supporting layer 301 is a cylindrical porous structure formed by the adhesion of a plurality of crushed stones. The outer diameter of the supporting layer 301 is adapted to the inner diameter of the tank, so that the supporting layer 301 is bonded and fixed on the inner wall of the tank. The volume of the micro electric reaction area accounts for 4/5 of the volume of the inner cavity of the tank, and the height of the supporting layer is about 0.3 m. The lower part of the micro electric reaction area is filled with a micro electrolytic reaction layer 302 which is composed of a mixture of activated carbon particles and iron chips. The micro electrolysis reaction layer 302 is formed by a mixture of iron chips and activated carbon particles with a weight ratio of 3:1-4:1. And the total volume of it accounts for 3/5 of the volume of the micro electric reaction area. The iron chips shall be iron shavings or scrap iron chips treated by membrane to remove oil and deoxidize, and the particle size range is 2.0-5.0 mm, and that of activated carbon particles is 1.5-3.0 mm. A second water inlet pipe 303 is arranged at the bottom of the reaction tank 3, and an air inlet pipe 304 is arranged on the side wall of the tank aeration mixing area. The second water outlet pipe 305 is arranged on the side wall of the micro electric mixing area of the tank, and an ultrasonic transducer 306 is arranged on the top of the tank. Besides, the second water outlet 305 is provided with a second flow regulating valve. The regulating tank 1 is connected with the reaction tank 3. Specifically, the first water outlet pipe 102 is connected with the second water inlet pipe 303 through a connecting pipe. In addition, a lifting pump 2 and a first flow regulating valve 4 are arranged on the connecting pipe. The first flow regulating valve 4 meets the requirement that the retention time of wastewater in the reaction tank 3 is 1-1.5 h. The outer nozzle of the air inlet pipe 304 is connected with the air pump 5 arranged on the adjacent side of the reaction tank through the pipeline, so that the air could be pumped into the aeration mixing area, and the tank washings to be treated will mix with air there. And then the mixture enters the micro electric reaction area through the supporting layer 301. A gas flow regulating valve is arranged on the air inlet pipe 304 to control the gas-liquid mixing ratio in the aeration mixing area. One end of the ultrasonic energy conversion 306 is connected with the ultrasonic generator 6, and the other end extends to the top of the micro electrolysis reaction layer 302. The ultrasonic generator 6 is set on the adjacent side of the reaction tank 3, and its frequency is set as 40 Hz. The working principle of the water treatment system for port chemical tank washings based on ultrasonic enhanced micro electrolysis is as follows: Firstly, the chemical tank washings flow into regulating tank 1, where the water fluctuation is regulated. Then, it is lifted to reaction tank 2 by lifting pump. After that, the ultrasonic generator 6 is started, at the same time, the gas flow regulating valve is opened. The air is pumped to the aeration reaction area according to a certain gas-liquid mixing ratio, and it mix with the regulated chemical tank washings there. Then, the mixture enters the micro reaction area through the supporting layer 301 and reacts with the micro electric forming layer. The scrap iron and activated carbon particles form a micro primary battery. The electrons on Feo are continuously transferred to H', forming a strong reducing agent [H], which can quickly reduce the refractory organics to the easily oxidized or biodegraded organics. At the same time, there are two combined effects of flocculation-adsorption and co-sedimentation in the reaction tank, that is, the colloid in suspension state combines with the suspended matter to form particles that are easy to precipitate, and cause other coexisting soluble substances to precipitate together, so as to achieve the purpose of removing chromaticity and pollutants, and effectively reduce the load of subsequent biological treatment process. After the port chemical tank washings treatment system of the embodiment is used to treat the tank washing water of a ship in the port, the corresponding environmental indicators of the tank washings before and after treatment are shown in Table 1 below. Table 1: Processing Stage Wastewater Condition COD BOD 5 /COD High pollution Before concentration; 400 mg/L 0.1 Difficult to biodegrade The pollutant concentration After decreases; 160~200mg/L 0.3- 0.4 Biodegradable It can be seen from table 1 that the COD removal rate of the port chemical tank washings treatment system for high concentration chemical tank washings can reach ~60 %, and the biodegradability (BOD 5/ COD) can be improved from 0.1 to 0.3~0.4. Therefore, after the treatment of the system, the effluent can be connected to the municipal sewage treatment plant for further treatment or connected to the biological treatment system for further degradation of small molecular organics to meet the requirements of the discharge standard. The embodiments above are only the specific embodiments of the utility model, which are used to illustrate the technical scheme of the utility model, rather than limiting it. The scope of protection of the utility model is not limited to that. Although the utility model has been described in detail with reference to the aforementioned embodiments, it should be understood by those skilled in the art that, within the technical scope disclosed by the utility model, any person skilled in the art can still modify the technical scheme recorded in the aforementioned embodiments or easily think of changes, or replace some of the technical features equally. Those modifications, changes or substitutions do not make the essence of the corresponding technical scheme deviate from the spirit and scope of the technical scheme of the embodiment of the utility model, on the contrary, they shall be covered in the protection scope of the utility model. Therefore, the protection scope of the utility model shall be subject to the protection scope of the claims.

Claims

We Claim:

1. A water treatment system for port chemical tank washings based on ultrasonic enhanced micro electrolysis, which includes a regulating tank, a reaction tank and an ultrasonic generator; wherein the regulating tank is a tank with a top opening, and a first water inlet pipe is arranged on an upper portion of a side wall, and a first water outlet pipe is arranged at an opposing lower portion of a side wall; wherein the reaction tank is a closed cylindrical tank, in which a supporting layer is arranged, so that an inner cavity of the reaction tank is divided into a micro electrolytic reaction area at an upper part and an aeration mixing area at a lower part, and the supporting layer, which is fixed on an inner wall of the reaction tank, is a cylindrical porous structure formed by adhesion of a plurality of crushed stones, and a lower part of the micro electrolytic reaction area is filled with a micro electrolytic reaction layer which is composed of a mixture of activated carbon particles and iron chips; a second water inlet pipe is arranged at a lower portion of the reaction tank, and an air inlet pipe is arranged on a side wall of the aeration mixing area; a second water outlet pipe is on a side wall of the micro electrolytic mixing area of the reaction tank, and an ultrasonic transducer is arranged on top of the reaction tank, wherein the ultrasonic transducer is connected with an ultrasonic generator, and the ultrasonic transducer extends to the top of the micro electrolysis reaction layer; and wherein the first water outlet pipe is connected with the second water inlet pipe through a connecting pipe, and a lifting pump and a first liquid flow regulating valve are arranged to the connecting pipe; and wherein the outer end port of the air inlet pipe is connected with an air pump through a pipeline.

2. The water treatment system for port chemical tank washings based on ultrasonic enhanced micro electrolysis according to claim 1, wherein, the frequency range of the ultrasonic generator is 20~40 Hz.

3. The water treatment system for port chemical tank washings based on ultrasonic enhanced micro electrolysis according to claim 1, wherein, volume of the micro electric reaction area accounts for 4/5 of volume of the inner cavity of the tank, and height of the supporting layer is 0.1~0.3m.

4. The water treatment system for port chemical tank washings based on ultrasonic enhanced micro electrolysis according to claim 1, wherein, volume of the micro electrolysis reaction layer accounts for 3/5~4/5 of volume of the micro electrolysis reaction area.

5. The water treatment system for port chemical tank washings based on ultrasonic enhanced micro electrolysis according to claim 1, wherein, the micro electrolysis reaction layer is formed by a mixture of iron chips and activated carbon particles with a weight ratio of 3:1-4:1 and the total volume of the micro electrolysis reaction layer accounts for 3/5 of the volume of the micro electric reaction area; and wherein the particle size range of iron chips is 2.0~5.0 mm, and the particle size range of activated carbon particles is 1.5-3.0 mm.

6. The water treatment system for port chemical tank washings based on ultrasonic enhanced micro electrolysis according to claim 1, wherein, tahe flow regulating range of the first liquid flow regulating valve meets the requirement that retention time of wastewater in the reaction tank is 1-1.5 h.

7. The water treatment system for port chemical tank washings based on ultrasonic enhanced micro electrolysis according to claim 1, wherein, at least one lifting pimp is arranged in the regulating tank.

8. The water treatment system for port chemical tank washings based on ultrasonic enhanced micro electrolysis according to claim 1, wherein, a second liquid flow regulating valve is arranged on the second water outlet pipe, and an air flow regulating valve is arranged on the air inlet pipe .