KR100732653B1 - Purification apparatus of groundwater which is contaminated by heavy metals - Google Patents

Abstract

A purification apparatus of groundwater contaminated with heavy metals, which is excellent in treatment performance and treatment capacity of contaminated groundwater containing heavy metals, in particular, contaminated groundwater having a high content of arsenic, is provided. A purification apparatus of groundwater contaminated with heavy metals comprises: a catchment tank(10) for storing contaminated groundwater pumped from a raising water well; a reactor(20) for separating heavy metals from contaminated groundwater using slaked lime and limestone; a pH adjusting tank(30) for adjusting a pH of treated water from which heavy metals are removed to the discharge regulation; and a storage tank(40) for storing the treated water before discharging the treated water into a river. The reactor is designed as a downward inflow type or an upward inflow type. The reactor contains a slaked lime stacked in a lower column thereof, and a limestone stacked in an upper column thereof at a weight ratio of 1:1. The pH adjusting tank includes a hydrochloric acid injector(34), an agitating motor(35), and a pH meter(36).

Description

Purification Apparatus of groundwater which is contaminated by heavy metals}

1 is a flowchart of a water treatment process using the purification apparatus of the present invention.

2 is a view schematically showing a purification apparatus of the present invention.

Figure 3 is a view showing another embodiment of the reaction tank of the purifier of the present invention.

4 is a graph showing the heavy metal removal efficiency of the reaction tank of the present invention (artificial contaminant results).

5 is a graph showing the heavy metal treatment capacity of the reaction tank of the present invention (artificial contaminated water results).

6 is a graph showing the cumulative removal of heavy metals in the reaction tank of the present invention (artificial contaminated water results).

7 is a graph showing the heavy metal removal efficiency of the reaction tank of the present invention (actual contaminant results).

8 is a large column experiment graph showing the heavy metal removal efficiency of the reaction tank of the present invention (actual contaminated water results).

* Explanation of symbols for main parts of drawings *

1: positive crystal

2: motor

10: sump tank 11: groundwater inlet

12: groundwater discharge port 13: sludge discharge port

20, 20 ': Reactor 21, 21': groundwater inlet

22: treated water outlet 33: waste treatment agent outlet

24: limestone column 25: limestone column

26: rainproof cap

30: pH adjusting tank 31: treated water inlet

32: treated water outlet 33: sludge outlet

34: hydrochloric acid injector 35: stirring motor

36: pH meter

40: reservoir 41: treated water inlet

42: treated water outlet

The present invention relates to an apparatus for purifying contaminated ground water, and more particularly, to an apparatus for purifying ground water contaminated with heavy metals.

The present invention relates to an apparatus for purifying contaminated ground water, and more particularly, to an apparatus for purifying ground water contaminated with heavy metals.

As a method of purifying ground water, as disclosed in Korean Patent Registration No. 10-0414770, there is a method of sterilization using ozone, a method of using microorganisms, and the like. These methods are aimed at disinfecting and disinfecting organics and are not suitable for the purification of groundwater from soils contaminated with heavy metals. In addition, recently, methods using inorganic salts such as iron salts and aluminum salts have been developed, but these compounds are relatively expensive, and heavy metal removal performance is not sufficient. In order to solve the problems of the known method, the inventors have developed and applied for a new method for removing heavy metals using a combination of slaked lime and limestone.

Accordingly, it is an object of the present invention to provide a purifier for purifying contaminated groundwater containing heavy metals.

An object of the present invention is a water collecting tank for pumping and storing the contaminated groundwater from the pumping well, a reaction tank for separating heavy metals from the contaminated groundwater using slaked lime and limestone, pH adjustment tank and streams to meet the discharge standards of the pH of the treated water from which heavy metals are removed Achieved by a clarifier of heavy metal contaminated groundwater consisting of a reservoir that stores treated water prior to discharge.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

1 is a flowchart of a water treatment process using the purification apparatus of the present invention. First, contaminated groundwater is collected in the sump, and sludge is removed and sent to the reactor. The contaminated groundwater is treated in a reactor filled with slaked lime and limestone and the treated water is sent to a pH adjustment tank. Waste treatment is removed with sludge. In the pH adjustment tank, the pH of the treated water from which the heavy metal is removed is adjusted to the emission standard using hydrochloric acid. The pH-adjusted treated water is sent to a reservoir that stores the treated water prior to discharge into the stream, analyzed for heavy metals and discharged.

2 is a view schematically showing a purification apparatus of the present invention. The contaminated ground water is sent to the water collection tank 10 through the groundwater inlet 11 by the driving of the motor 2 from the pump 1. Groundwater collected in the sump discharges the sludge through the sludge outlet 13 and the remaining ground water is introduced into the groundwater inlet 21 of the reactor 20 through the groundwater outlet 12. Inside the reactor 20, limestone 24 and slaked lime 25 columns are sequentially filled, and groundwater is treated through this column to remove heavy metals. The treated water from which the heavy metal is removed is discharged through the outlet 22, and the waste treatment agent is removed through the outlet 23. 3 shows another embodiment of the reactor of the present invention. The reaction vessel 20 of FIG. 2 is a downward inflow method, whereas the reaction vessel 20 'of FIG. 3 is designed in an upward inflow manner so that the groundwater is introduced through the groundwater inlet 21' from the lower portion and the outlet 22 of the upper portion is introduced. To be discharged. The waste treatment agent is removed through the outlet 23.

The treated water treated in the reactor 20 is introduced into the pH adjusting tank 30 through the treated water inlet 31. The pH adjusting tank 30 is equipped with a hydrochloric acid injector 34, a stirring motor 35, and a pH meter 36. Hydrochloric acid is added through the hydrochloric acid injector 34 and stirred using the stirring motor 35. Adjust the pH of the treated water to the discharge standard. The pH adjustment is adjusted while measuring using the pH meter 36. The pH adjusted treatment water is sent to the reservoir 40 for storing the treated water before discharged to the stream through the outlet 32, the sludge produced in the pH adjustment process is discharged through the sludge outlet 33.

Example 1

Heavy metal removal performance experiments were conducted using the apparatus of the present invention. The concentration of heavy metals in the artificial contaminated water used in the experiment is

Table 1. Heavy Metal Concentrations in Artificially Contaminated Water

As (ppb) Ni (ppb) Zn (ppb) Artificial pollutant concentration 506 260 2315 Groundwater Standard Water Concentration 50 none 1500

The experiment was carried out by installing a column reactor for granite limestone and granulated limestone (manufactured by Hanil lime) for fertilizer limestone and limestone. The reactor used an upflow type reactor. In order to minimize the amount of suspended solids in the treated water and to prevent clogging of treated water, granular (diameter 2-5 mm) slaked lime and quicklime were used.

A glass column having a diameter of 5 cm and a length of 15 cm connected to a valve and a tube was prepared. The column A was filled with 10 cm of granulated slaked lime, and the column B was filled with 5 cm of granulated slaked lime and 5 cm of limestone from the bottom. A standard solution for heavy metal analysis (purchased by ANAPEX Co., Ltd.) was injected into distilled water to prepare artificial contaminated water having As, Ni, and Zn concentrations of 506 ppb, 260 ppb, and 2315 ppb, respectively, and then using 1N NaOH solution. Artificial contaminated water was titrated to pH8, similar to the pH of field contaminated groundwater. Artificial contaminated water was injected into the column while maintaining an injection rate of about 2 ml / min (120 ml / hr) from the bottom of the column by the upflow method, and the treated water was collected every four hours from the column top to analyze the heavy metal concentration. A total of 10 liters of artificial polluted water were treated per column, and the treatment efficiency and treatment capacity of the flocculant were calculated by measuring the pH and heavy metal concentration of the treated water flowing out of the column. The results are shown in FIGS. 4-6.

As removal efficiency was maintained at almost 100% with respect to 10L of treated water, and Ni was maintained at 98% or more. In the case of Zn, the removal rate was initially 90% or more, but was lowered as the amount of contaminated water was increased, indicating a removal rate of 75% (FIG. 4). In the case of continuous column using slaked lime and limestone, the concentration of heavy metals (As and Zn) in the treated water could be lowered below the groundwater standard for living water, and the treated capacity was up to 548 μg / L / hr for As. 543 μg / L / hr and 2250 μg / L / hr, respectively (FIG. 5). The cumulative throughput of heavy metals also increased linearly during the treatment of 11 L of contaminated water, resulting in more than 11 L of contaminated water with an As concentration of 500 ppb for 225 g (196 ml) of the treatment agent (limestone + lime). Appeared. (50 times or more processing capacity) (FIG. 6).

Example 2

The continuous column experiment was repeated in the same manner as in Example 1 using in situ contaminated groundwater. The concentrations of heavy metals in contaminated site groundwater were As 496.7 ppb, Cd 0.7 ppb, and Zn 22.0 ppb. The result after processing through the column is shown in FIG. 7.

7 shows the heavy metal removal efficiency of a column using slaked lime and limestone together. The removal efficiency of As was over 99% for both types of groundwater, indicating that the removal efficiency was very good. In particular, in the case of the above-mentioned groundwater where the As concentration is about 10 times the groundwater standard for living water, the arsenic removal efficiency is maintained at 99% or more during the treatment of 17 liters (about 85 times the treatment agent capacity), thereby preventing the As contamination of the contaminated site. It was concluded that this method could be used very effectively to remove groundwater. The removal efficiency of Cd also showed high removal efficiency of more than 90%. The removal of As and Cd was very similar in all the continuous column experiments, and it was determined that two heavy metals could be treated simultaneously in one treatment process. Cumulative lime + limestone has been shown to have a water treatment capacity of about 85 times the capacity of the treatment agent by linearly increasing the cumulative removal of heavy metals treated with the increase of treated water.

As can be seen from the above, the apparatus of the present invention is excellent in the treatment performance and treatment capacity of contaminated ground water containing heavy metals, especially contaminated ground water with a high content of arsenic.

Claims (4)

A collection tank for pumping and storing the contaminated groundwater from the wells, a reaction tank for separating heavy metals from the contaminated groundwater using slaked lime and limestone, a pH adjusting tank for removing heavy metals from the treated water, and a treated tank before discharge to the stream. A device for the purification of groundwater contaminated with heavy metals consisting of a reservoir. The method of claim 1, wherein the reactor is a heavy metal contaminated groundwater purification device, characterized in that designed in a downward inflow or inflow. The apparatus of claim 1, wherein the lime is at the bottom of the column and the limestone is filled at the top of the column, and the lime and the limestone are filled at a weight ratio of 1: 1. 2. The apparatus of claim 1, wherein the pH adjusting tank is equipped with a hydrochloric acid input device, a stirring motor, and a pH meter.

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