KR100795153B1 - Composite treatment process for unspecific mixed wastewater by using inorganicnutrient salts - Google Patents

Abstract

A method for treating unspecific mixed wastewater is provided to remove pollutants effectively, by inputting buffering type nutrient salts and inorganic nutrient salts into a condensed water obtained by evaporating and condensing the unspecific mixed wastewater. High-concentration mixed wastewater is chemically treated to separate suspended materials. The treated wastewater is treated by an evaporating and condensing unit to generate condensed water. Microorganisms are activated by mixing KH2PO4 of 3-20 mg, K2HPO4 of 5-30 mg, Na2HPO4.12H2O of 27-90 mg, MgSO4.7H2O of 20-70 mg, FeCl3.6H2O of 0.2-2 mg, based on 1L of the condensed water, into the condensed water. The condensed water is biologically treated by the activated microorganisms.

Description

Composite treatment process for unspecific mixed wastewater by using inorganic nutrient salts}

1 is a process chart showing a treatment process of a high concentration mixed wastewater in accordance with the present invention.

The present invention relates to a method for effectively treating a high concentration of hardly decomposable mixed wastewater by administering a buffered nutrient and an inorganic nutrient (mineral) to a microorganism, and more specifically, a high concentration of organic, inorganic, heavy metals, etc. In the treatment of mixed hardly decomposed mixed wastewater, buffered nutrients and inorganic nutrients (minerals) are added to the condensate obtained by evaporating the mixed wastewater from which suspended solids are removed through an evaporative condenser. In order to effectively remove contaminants.

At present, a large amount of petrochemical, dyeing, plating, photography, pharmaceutical, dye, laboratory wastewater, etc., which can be classified as high concentration hardly degradable wastewater, is being discharged.

In particular, there are about 200 wastewater joint treatment companies (dyeing, plating, leather complexes, etc.) and non-specified wastewater treatment companies that are entrusted with various kinds of unspecified wastewater treatment. In addition to the high concentration of hardly decomposable heavy metals as well as a variety of pollutants, there is a significant difficulty in its proper treatment.

As a method of treating the high concentration hardly degradable wastewater, contaminants by boiling separation are removed by using an evaporation method. In the case of condensate obtained by using the evaporation method, chemical oxygen depends on the type of mixed wastewater introduced. Chemical oxygen demand (COD) is known to have a concentration of about 1,000 to 3,000 mg / l. In treating the condensed water obtained by the above-mentioned evaporation method, there are conventionally a method of administering a carbon-based adsorbent before biological treatment, and a biological treatment method in which a carrier is filled in the condensed water.

In particular, the present invention has been published regarding the process of applying carbon-based adsorbents and zeolites to biological treatments and general wastewater treatment methods for condensate of mixed wastewater, including the patents owned by the company including Patent No. 0329597 and Patent No. 0429680. Although there are several known technologies such as Korean Patent No. 0,044083 and Patent No. 0355196, organic pollutant load decreases depending on the throughput of chemicals, and it is helpful for the removal rate of organic solvents and odors. The lack of (minerals) poses a problem in terms of difficulty in microbial activity and the generation of secondary wastes due to the treatment cost or the aggregation and sedimentation of consumable activated carbon.

On the other hand, the biological treatment method of filling the evaporative condensate with the carrier only takes a large cost in terms of facilities, initially seemed to be well treated but mixed and dissolved with organic surfactants of high concentration mixed wastewater after several months. Due to the solvent waste water, a film is formed on the carrier pores and the surface, and in the case of the film-formed carrier, fluid fixation and sedimentation are caused by specific gravity difference, which often leads to a decay process, and microorganisms are difficult to activate without inorganic nutrients (minerals). This can be a problem because of the slow growth of microorganisms or the growth of other microorganisms.

Accordingly, the present invention is a conventional carbon-based adsorbent by injecting buffered nutrients and inorganic nutrients (mineral) to help the microorganisms activity in the condensate of high concentration mixed wastewater in an effort to solve the above problems. The purpose is to provide a treatment method suitable for the target water quality of the final treated water without using a process.

Accordingly, an object of the present invention is to provide an economical wastewater treatment method by reducing costs such as installation costs and operating costs using consumable activated carbon according to the installation of a process using a conventional carbon-based adsorbent.

Furthermore, it is an object of the present invention to provide an environmentally friendly wastewater treatment method by reducing the amount of sediment sludge, which is a secondary waste generated by flocculation and precipitation of consumable activated carbon.

In order to achieve the above object, the present invention, in treating a high concentration of unspecified mixed wastewater,

1 step of separating the suspended solids (SS) by chemical treatment of the high concentration of mixed wastewater introduced; and the second step of condensing the vapor evaporated through the evaporation condenser of the high concentration of mixed wastewater passed through the first step; and the second step Potassium phosphate (KH ₂ PO ₄ ) 3 to 20 mg, potassium diphosphate (K ₂ HPO ₄ ) 5 to 30 mg, diphosphate in buffered nutrients to help microbial activity per liter of condensate 27 to 90 mg of sodium (12 hydrate) (Na ₂ HPO ₄ · 12H ₂ O) and 1 to 6 mg of ammonium chloride (NH ₄ Cl) in inorganic nutrients, 20 to 70 mg of magnesium sulfate heptahydrate (MgSO ₄ · 7H ₂ O), calcium chloride dihydrate (CaCl ₂ · 2H ₂ O) 18 to 60mg, ferric chloride hexahydrate (FeCl ₃ · 6H ₂ O) 0.2 to 2mg is added to activate the microorganisms; and the step 3 condensed water by the activated microorganisms Four steps of processing are provided sequentially.

Therefore, the target water quality of the final treated water can be obtained without the conventional carrier filling and carbon-based adsorbent administration process, and the carbon-based adsorbent administration process can be reduced to reduce installation and operation costs required for the installation of the process as well as the adsorption process. The economical effect is enormous, since the consumable activated carbon to be administered is unnecessary.

In addition, it is a very useful invention, such as to provide an environmentally friendly wastewater treatment method can reduce the amount of waste due to sediment sludge generated by the consumable activated carbon.

Hereinafter, described in detail with reference to the accompanying drawings of the present invention.

1 is a process chart of the high concentration mixed wastewater in accordance with the present invention.

As shown in FIG. 1, the target wastewater to which the present invention is applied is petrochemical, dyeing, plating, photographing, pharmaceutical, dye, laboratory wastewater, which can be classified as a high concentration hardly degradable wastewater of various wastewater outlets. Contains heavy metals and suspended solids (SS) and is a contaminant of 20,000 to 100,000 ppm by chemical oxygen demand (COD).

When a high concentration of mixed wastewater is introduced, most of the suspended solids (SS) are separated in the chemical treatment process of the first stage, and inorganic salts and heavy metals are not separated. The chemical oxygen demand (COD) is about 20,000ppm.

The mixed wastewater passed through the first stage is subjected to a two-stage process of evaporation and condensation through an evaporator. In the two-step process, suspended solids (SS), inorganic salts and heavy metals are mostly removed, and the chemical oxygen demand (COD) of the treated water after the two-step process is about 1,000 to 3,000 ppm. Conventionally, after passing the two-stage process, the carbon-based adsorbent or zeolite is administered to remove the solvent and the malodorous component. However, the present invention provides a microorganism for the activation of microorganisms instead of the step of administering the carbon-based adsorbent. A three-step process is provided to provide buffered nutrients and inorganic nutrients (minerals) to aid activation.

In general, the major constituents of microorganisms (fungi, protozoa, higher animals) are the water, organics and minerals. In order to maintain these biological constituents, microorganisms in wastewater decompose contaminated wastewater, It is supplied with biological components such as buffered nutrients and inorganic nutrients (minerals) among water, organics and inorganics, especially minerals. However, the lack of such biological components inhibits the growth of microorganisms or inactivates the microorganisms, so that the wastewater decomposition of the microorganisms is not smooth, and thus, the buffer nutrients and inorganic nutrients that help the microorganisms are active in these bioconstituents. Potassium Phosphate (Potassium Phosphate, Monobasic, KH ₂ PO ₄ ) Potassium Phosphate (Dibasic, K ₂ HPO ₄ ), J. Sodium Phosphate, Dibasic, Dodecahydrate, Na ₂ HPO ₄ · 12H ₂ O) Ammonium Chloride, NH ₄ Cl, Magnesium Sulfate Heptahydrate, MgSO ₄ Dihydrate (Calcium Chloride Dihydrate, CaCl ₂ · 2H ₂ O), Ferric Chloride Hexate (Iron (III) Chloride Hexahydrate, FeCl ₃ · 6H ₂ O), etc. The concentration of each of the buffer nutrients and the inorganic nutrient salts was adjusted to 100 ppm or less.

The condensate that has passed through the three steps is discharged through four steps that are biologically treated by the activated microorganism. At this time, the chemical oxygen demand (COD) of the treated water discharged was about 10 to 30 ppm, thereby obtaining a target water quality.

Hereinafter, the present invention is specifically illustrated by way of examples.

(Example 1)

Potassium Phosphate (Potassium Phosphate, Monobasic, KH ₂ PO ₄ ), a buffering nutrient and an inorganic nutrient mineral, in 1 liter of condensate from a high concentration of mixed wastewater, Potassium Phosphate, Dibasic, Anhydrous, K ₂ HPO ₄ ) 7400mg, Sodium Phosphate, Dibasic, Dodecahydrate, Na ₂ HPO ₄ 12H ₂ O) 27,500mg, Ammonium Chloride, NH ₄ Cl 1700mg, Magnesium Sulfate Heptahydrate 20,800 mg of Sulfate Heptahydrate, MgSO4 · 7H2O, 18,700 mg of calcium chloride dihydrate (CaCl ₂ · 2H ₂ O), 250 mg of ferric chloride hexahydrate (Iron (III) Chloride Hexahydrate, FeCl ₃ · 6H ₂ O) To prepare. During biological treatment, the pH of the prepared solution is adjusted to neutral pH (pH = 6.8 to 7.2), and then 1 ml per liter of condensate is injected, so that the biological oxygen demand (BOD) load is 0.15 to 0.4 (kg BOD / The activation and chemical oxygen demand (COD) of microorganisms were measured under conditions of m ³ .day, Dissolved Oxygen (DO) 1 to 4 ppm, and Mixed Liquor Suspended Solid (MLSS) 5,200 ppm to 7,000 ppm. The results are shown in Table 1 below.

Table 1. Changes in Chemical Oxygen Requirements Experimented with Wastewater Treatment Methods According to the Present Invention

Processing Process COD (ppm) Removal rate Remarks High concentration influent mixed wastewater 20,000-100,000 After 1 step chemical treatment 5,000-20,000 To 80% ss removal Condensate Concentration after Two Stage Evaporation and Concentration 1,000-3,000 -98% Heavy metal removal Input of three-stage buffered nutrients and inorganic nutrients - - Mineral input After 4 stage biological treatment 10-30 More than 99% Discharge

As shown in the above Table 1, high concentration of mixed wastewater is introduced and does not go through the carbon-based adsorbent process, and the biological treatment of four stages through the input process of buffered nutrients and inorganic nutrients (mineral) to help the microorganism activity. The discharged water showed more than 99% of COD removal rate. Especially, the concentration of condensate after evaporation and concentration shows stable biological treatment result by COD 3,000 high concentration wastewater. In particular, the operating cost burden is reduced by about 90% or more compared to the carbon-based adsorbent administration process, it is a revolutionary invention that can significantly reduce the cost. In particular, three buffered nutrients, potassium phosphate (Potassium Phosphate, Monobasic, KH ₂ PO ₄ ), potassium phosphate (Potassium Phosphate, Dibasic, Anhydrous, K ₂ HPO ₄ ), dibasic sodium phosphate (12) Phosphate, Dibasic, Dodecahydrate, Na ₂ HPO ₄ · 12H ₂ O) are not sensitive to PH change and stable, so it has a great effect on the activation of microorganisms and acts as a factor to increase the activated sludge concentration (MLSS). Ammonium Chloride (NH ₄ Cl), Magnesium Sulfate Heptahydrate (MgSO4 · 7H2O), Calcium Chloride Dihydrate (CaCl ₂ · 2H) ₂ O), ferric chloride hexahydrate (Iron (ⅲ) chloride hexahydrate, FeCl 3 · 6H 2 O) to cause the bulking phenomenon caused by the precipitated defective when an error occurs according to the biological process by introducing an additional four kinds there It was confirmed that the solution can be solved by adding this mineral.

(Example 2)

Sixty six liters of condensate water, which had been subjected to the two-step process of Example 1, were prepared, and aeration tank pilot device was installed to prepare wastewater treatment by microorganisms continuously. Wastewater treatment experiment by the method of administration of the mineral) and the microbial carrier filling was carried out. During 4 weeks of seeding period, 3,400ppm of activated sludge (MLSS), 1,000 ~ 1,200ppm of chemical oxygen demand (COD), and 30ppm of TN were applied to both methods, and minerals (P, Ca, K) were applied. , Mg, Na, Fe, S, Cl) was applied only to the method of administering buffered and inorganic nutrients. From 5 weeks after seeding, high concentrations of chemical oxygen demand (COD) are 2,850 to 3,000 ppm, TN is 60 to 90 ppm, and biological oxygen demand (BOD) load is 0.15 to 0.4 (kg BOD / m ³ .day). The minerals (P, Ca, K, Mg, Na, Fe, S, Cl) were applied only to the buffered and inorganic nutrients and were continuously tested for 3 months. The results are shown in Table 2 below.

Table 2. Changes in Chemical Oxygen Demand (COD) after Wastewater Treatment Using Wastewater Treatment and Carrier Filling Methods

 division Treatment method How to administer minerals Carrier filling method Condensate Concentration after Two Stage Evaporation and Concentration 1,000-3,000 1,000-3,000 Three steps - - Concentration after 4 stage biological treatment 30 or less 80 or less

Comparing the COD concentration of the treated water discharged through the four-step process as shown in Table 2 above, buffer nutrients and inorganic nutrients (minerals) were added compared to the case where the waste water was treated by the carrier-filled method. In this case, it can be seen that the processing efficiency is about 2 to 3 times higher. In addition, as described above, the carrier-filled method will be very effective in view of the difficulty of obtaining expensive initial facility investment costs and continuous stable treatment efficiency.

According to the configuration of the present invention as described above, the target water quality of the final treated water can be obtained without the conventional carrier filling and carbon-based adsorbent administration process, and the installation and operation costs required for the installation of the process by reducing the carbon-based adsorbent administration process In addition, the economical effect is enormous since the depleted activated carbon administered in the adsorption process is unnecessary.

In addition, it is possible to reduce the amount of waste due to the settling sludge produced by the consumable activated carbon is very useful invention, such as providing an environmentally friendly wastewater treatment method.

Claims (2)

In treating high concentrations of unspecified mixed wastewater, 1 step of separating the suspended solids (SS) by chemical treatment of the high concentration of mixed wastewater introduced; Condensing the vapor evaporated through the evaporator to the high concentration of mixed wastewater passing through the first step; and Potassium Phosphate (Potassium Phosphate, Monobasic, KH ₂ PO ₄ ) 3 to 20 mg of potassium phosphate (Potassium Phosphate) among buffering nutrients that help microbial activity per 1 liter (liter) of condensate in the condensate that has passed step ₂ , Dibasic, Anhydrous, K ₂ HPO ₄ ) 5 to 30 mg, sodium phosphate (12 hydrate) (Sodium Phosphate, Dibasic, Dodecahydrate, Na ₂ HPO ₄ 12H ₂ O) 27 to 90 mg and ammonium chloride in inorganic nutrients Chloride, NH ₄ Cl) 1 to 6 mg, Magnesium Sulfate Heptahydrate (MgSO 4 · 7H 2 O) 20 to 70 mg, Calcium Chloride Dihydrate (CaCl ₂ 2H ₂ O) 18 to 60 mg, Ferric Chloride Hexate (Iron (III) Chloride Hexahydrate, FeCl ₃ · 6H ₂ O) ₃ to add 0.2 to 2 mg to activate the microorganisms; And Unspecified mixed wastewater complex treatment process using inorganic nutrients, characterized in that the four stages of biological treatment of the condensate of the three stages by the activated microorganism sequentially delete

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