JP2001281240A - Water turbidity analyzer - Google Patents

Abstract

(57) [Summary] [Problem] Discharged water and river water in each wastewater treatment process,
When monitoring the quality of environmental water such as lake water, especially when using a water quality measuring instrument to measure soluble components, turbidity such as sand, mud, and dust in the sample accumulates in the piping in the device, There is a possibility that the blockage of the pipe and the accompanying failure of the device may occur. An object of the present invention is to provide a water quality measuring instrument that solves these problems. An external pressure type hollow fiber membrane module is used for a pretreatment unit of a water quality measuring instrument. In addition, a washing mechanism for the hollow fiber membrane module that removes suspended matter adhering to the membrane surface by injecting air into the inside of the hollow fiber membrane to reverse the filtrate, and a sludge removing mechanism for removing sand, mud, etc. accumulated in the piping and the main tank. In addition, a sample water tank that is shielded from light to prevent algae from breeding is provided, and a sample is stably supplied to a water quality measuring instrument.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water quality measuring instrument for monitoring the chemical components in water for environmental water such as water, river water, lake water, and the like in water, water and wastewater treatment processes. .

[0002]

2. Description of the Related Art Monitoring of the quality of environmental water such as effluent water, river water, lake water and the like in each wastewater treatment process is very important from the viewpoint of safety as a tap water source and environmental conservation.
Currently, a water quality measuring instrument for automatically monitoring water quality has been developed and actually applied. Such water quality measuring instruments include pH meter, conductivity meter, free chlorine meter, dissolved oxygen meter,
Examples include an ammonia meter, a UV organic pollution meter, a chemical oxygen demand (COD) meter, a total organic carbon (TOC) meter, and a toxic monitor using a biosensor.

In practice, when measuring environmental water such as effluent water, river water, lake water, etc. in each wastewater treatment process, it is necessary to perform a pretreatment to remove turbid substances such as sand, mud, and dust contained in the sample. It is. Conventionally, the sample is filtered with laminated sand or nonwoven fabric,
Devices that remove turbidity have been used. However, they cannot remove turbidity of 10 μm or less, block the piping of each water quality measuring instrument, and have the drawback that it takes time to replenish or replace sand or nonwoven fabric. there were.

[0004]

SUMMARY OF THE INVENTION In monitoring the quality of discharged water, river water, lake water, and other environmental water in each wastewater treatment process, a water quality measuring instrument specifically for measuring soluble components is used. In such a case, turbid substances such as sand, mud, and dust in the sample may accumulate in the piping in the device, which may cause blockage of the piping and a resulting failure of the device.

The present invention has been made to solve the above-mentioned problem, and has as its object to stably supply a sample to a water quality measuring instrument.

[0006]

According to the present invention, in order to solve the above-mentioned problems, as set forth in claim 1, it is provided before and after a sample water tank to supply raw water such as river water or groundwater, or under water.
A turbidity removal device as a pretreatment unit of a water quality measuring device that measures a chemical substance in the influent water of the wastewater treatment process is configured to pass water through the external pressure type hollow fiber membrane module and perform suction filtration.

[0007] The filtration method using the hollow fiber membrane includes an internal pressure type in which the sample is filtered from the inside of the hollow fiber membrane to the outside and an external pressure type in which the sample is filtered from the outside of the hollow fiber membrane to the inside.
In order to filter samples with high turbidity such as sand and mud such as effluent water from each wastewater treatment process, river water, and lake water, etc., the internal pressure type hollow fiber membrane has turbidity inside the hollow fiber membrane. Blocks quickly with quality. Therefore, in the present invention, an external pressure type hollow fiber membrane module having a pore diameter of 0.1 μm which can maintain the filtration performance for a long period of time even for a sample having a large amount of turbidity is adopted.

Next, as set forth in claim 2, air is injected into the hollow fiber membrane, and a washing mechanism is provided for the hollow fiber membrane module for removing the turbidity adhering to the membrane surface by causing the filtrate to flow backward. I do. As a cleaning method for removing turbidity adhered to the surface of the hollow fiber membrane module, a method of generating air bubbles from the lower part of the hollow fiber membrane module with an air pump and vibrating the hollow fiber membrane module to remove turbidity adhered to the membrane surface, There are two methods: removing air adhering to the membrane surface by injecting air into the fiber membrane module with an air pump. Generally, environmental water such as effluent water from each treatment process of wastewater, river water, lake water, etc. The method of is adopted. However, the environmental water contains a lot of iron ions, and in the washing method, iron ions in the water are oxidized by oxygen in bubbles to form iron oxide, and these fine particles enter micropores on the hollow fiber membrane and become hollow. The thread membrane is clogged early. Therefore, there has been a problem that the chemical solution such as citric acid must be frequently cleaned or replaced. In the cleaning mechanism of the hollow fiber membrane module of the water turbidity measuring device of the present invention, the following cleaning method is adopted.

According to a third aspect of the present invention, there is provided a sludge discharging mechanism for removing sand, mud and the like accumulated in the pipe and the main body water tank. In order to improve the performance of the equipment in terms of maintenance, in order to remove suspended matter such as sand and mud that accumulates in the piping that feeds the sample to the equipment and the main water tank that holds the hollow fiber membrane module, water is supplied in the middle of the piping. A pipe for supplying water and a drain for discharging suspended matter such as sand and mud will be provided. Further, the bottom of the water tank is inclined so that turbid substances such as sand and mud deposited on the bottom of the water tank when the main body water tank is washed are easily discharged to the drain.

It is preferable that the sample tank is shielded from light and has a structure in which algae and the like cannot propagate in the sample tank.

[0011]

FIG. 1 shows an embodiment of the present invention. The water turbidimeter decontamination device includes a main body water tank 2 containing a hollow fiber membrane module 1, an air pump 3, a sample filtration suction pump 4, a pressure sensor 5, a two-way switching three-way solenoid valve 7, a controller 8, a drain valve 9. , 10 and the like, and the clarified filtrate is sent to the sample tank 6 and then sent to the water quality measuring device as shown in FIG.

In operation, the sample is sucked through the hollow fiber membrane module 1 by the sample filtration suction pump 4 for a certain period of time, and the filtrate is sent to the sample water tank 6. Filtration and cleaning of the hollow fiber membrane module 1 are alternately performed by a timer of the control unit 8. The filtered sample is sent to each water quality measuring device to be measured. At this time, the sample filtration suction pump 4 side of the two-way switching three-way solenoid valve 7 is opened, and the air pump 3 side is closed. In addition, the main body water tank 2 side of the drain valve 9 is opened, the drain side is closed,
The drain valve 10 closes.

FIG. 3 shows the difference in the life of the hollow fiber membrane module depending on the method of cleaning the hollow fiber membrane module. The vertical axis is the suction pressure (Pa ) Indicates that the hollow fiber membrane module is a measure of clogging. An increase in this value indicates that the hollow fiber membrane module is clogged. The broken line is a method in which air bubbles are generated from the lower part of the hollow fiber membrane module by an air pump to vibrate the hollow fiber membrane module to remove suspended matter adhered to the membrane surface. Then, a method for removing turbidity adhering to the membrane surface, and a washing method will be described below. The use limit of the hollow fiber membrane module used in the present invention is a suction pressure of about 70 kPa. It was found that the hollow fiber membrane module could not be used in about one month in the cleaning method, but could be used continuously for one year or more in the cleaning method. Therefore, the present invention employs a cleaning method.

When the hollow fiber membrane module 1 is washed, the two-way switching three-way solenoid valve 7 is closed on the sample filtration suction pump 4 side, the air pump 3 side is opened, and the air pump 3 is operated. Inject for a few seconds and reverse the internal filtrate to remove turbidity adhering to the membrane surface. The pressure sensor 5 constantly measures the suction pressure of the sample filtration suction pump 4, which is an index of clogging of the hollow fiber membrane module 1. If the suction pressure exceeds the set value, the hollow fiber membrane module 1 is automatically cleaned.

Washing of a pipe for feeding a sample to the apparatus is performed by closing the main body water tank 2 side of the drain valve 9, opening the drain side, and flowing tap water therethrough. Cleaning of the bottom of the main body water tank 2 is performed by opening the main body water tank 2 side of the drain valves 10 and 9 and flowing tap water. As shown in FIG. 2, the sample tank 6 is sealed with a lid 61 so that dust in the air does not enter, and is shielded from light by a light-shielding film 60 to prevent the growth of algae. Generation can be prevented, and a stable filtered sample can be supplied without blocking the piping of the water quality measuring instrument with algae.

[0016]

According to the present invention, the clarifier for a water quality measuring instrument is as follows.
In monitoring the quality of discharged water, river water, lake water, and other environmental water in each wastewater treatment process, turbidity such as sand and mud in the sample can be efficiently removed. Since the failure of the device can be prevented, it can be used particularly for a water quality measuring instrument for measuring a soluble component.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a water turbidity measuring device of the present invention.

FIG. 2 is a schematic diagram of a sample water tank of the clarifier for a water quality measuring instrument of the present invention.

FIG. 3 is a diagram showing a difference in the life of a hollow fiber membrane module depending on a cleaning method.

[Explanation of symbols]

 1: hollow fiber membrane module 2: main body water tank 3: air pump 4: sample filtration suction pump 5: pressure sensor 6: sample water tank 7: two-way switching three-way solenoid valve 8: control unit 9, 10: drain valve 60: light shielding Film 61: Lid

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ryo Shirasaki, 1st Asahi, Asahi, Tsukuba, Ibaraki Prefecture Inside the Public Works Research Institute, Ministry of Construction (72) Inventor Hiroaki Tanaka 1st Asahi, Asahi, Tsukuba City, Ibaraki Prefecture, Inside the Public Works Research Institute, Ministry of Construction (72) Inventor Kazuyuki Taguchi 2-2-1 Nagasaka, Yokosuka City, Kanagawa Prefecture Inside Fuji Electric Research Institute, Inc. (72) Inventor Yoshiharu Tanaka 2-2-1 Nagasaka, Yokosuka City, Kanagawa Prefecture F-term in Fuji Electric Research Institute, Inc. (Reference) 4D006 GA07 HA02 HA19 HA93 JA67A KC03 KC14 KE08Q KE22Q KE23Q KE24Q KE28Q MA01 MA22 PA01 PB04 PB05 PB08 PC80

Claims (3)

[Claims] 1. A turbidity removal device as a pretreatment unit of a water quality measuring device provided before and after a sample water tank and measuring chemical substances in raw water of tap water such as river water and groundwater, and inflow water of a wastewater treatment process, A turbidity separator for a water quality measuring instrument, wherein water is passed through an external pressure type hollow fiber membrane module to perform suction filtration. 2. The hollow fiber membrane module according to claim 1, wherein air is injected into the hollow fiber membrane to reverse the filtrate to remove turbidity adhering to the membrane surface. A clarifier for a water quality measuring instrument, comprising a washing mechanism. 3. The water turbidity measuring device according to claim 1, wherein the sand deposited in the pipe and the main body water tank is provided.
A clarifier for water quality measuring instruments, comprising a sludge discharging mechanism for removing mud and the like.