SU891574A1 - Method of clarifying waste water - Google Patents

Description

The invention relates to wastewater treatment, specifically to the treatment of surface wastewater, and can be used in the metallurgical and metalworking industry. One of the sources of pollution of public water bodies is surface run-off (up to xdiye, thawed, watering and washing), washing away from the territory of industrial enterprises various soils, mainly solids, which in the form of suspended particles enter the water bodies. The content of suspended solids in the discharge discharged into reservoirs shall not exceed 10-15 mg / l. Research has shown that in surface runoff from the territory of titanium-magnesium plants the content of suspended solids is 50-2000 mg / l. It is known that the simplest method of purifying wastewater from suspended substances is sedimentation. The disadvantage of this method is the low degree of purification from suspended substances and the duration of the process. The closest to the proposed method to the technical nature is the method of clarification of surface wastewater, which includes treatment with an alkaline agent (pH 7.08, 0), the introduction of powdered cleaning agent and coagulant of a high-molecular polymer and separation of the precipitate formed in the reactor with appropriate dynamic characteristics, necessary to clarify water by dynamically separating sludge. The slurry is then subjected to a separation process in a hydrocyclone, after which the separated cleaning agent is reused in the purification scheme, and the contaminants pressed with combustible components are burned 2. However, the process provides for an independent technological process.

the operation of adjusting the pH of the effluent to 7-8, which requires the consumption of an alkaline reagent. A special reactor with certain dynamic characteristics is required to carry out the cleaning process.

In addition, in order to regenerate the powdered cleaning agent, a third technological step is envisaged - separation of the sludge in a hydrocyclone.

Thus, the technological scheme of surface water treatment is cumbersome and requires sophisticated equipment.

The purpose of the invention is to increase the degree of purification from suspended substances and simplify the method.

The goal is achieved by the fact that surface wastewater is treated with titanium-magnesium production wastes containing calcium chloride, calcium carbonate and calcium oxide in an amount of 10-20, 2.5-3 0.2-0.3 g / l waste, respectively; and waste in an amount of 2050 ml / l of wastewater is introduced.

The proposed method of cleaning surface wastewater from suspended substances is carried out as follows.

Pulp is injected into drains at the rate of 20-50 liters per 1 m of wastewater, stirred for 10 minutes and settled for 1 day.

The cleaning process is carried out unheated at ambient temperature.

Deposition can be carried out in radioactive settling tanks of industrial enterprises widely used in sewage treatment plants.

Due to the presence of CaO in the pulp, the pH is adjusted to 7–7, Calcium chloride causes coagulation of suspended solids, and solid CaCOrt particles contribute to the sedimentation of coagulated suspensions, carrying them to the bottom of the settling basin. As a result, satisfactory clarification of surface runoff occurs. The content of suspended matter in clarified water is 10–20 kg / l, which meets the regulatory requirements for

treated water. Thus, instead of several operations, as in the known method, one is performed.

Example K A runoff sample containing 792 mg / l of suspended solids, having a pH of 6.8, was used in the experiments. To 1 l of wastewater 10 ml of pulp was added, containing: g, l / g: CaCl2 1.5; CaCOj 2.90 and CaO 0.3. After stirring for 10 minutes, the pH is determined and the sample is poured into 3 measuring cylinders with a capacity of 250 ml. At regular intervals (17.2 and 48 hours)

5, a sample of clarified water is taken from the upper part of the cylinder to a depth of 100 mg and the content of suspended substances in it is determined.

Then to 1 l of sample is introduced 20 ml.

pulp, and in another portion 50 ml of pulp and completely repeat the research. For comparison, the experiment was performed without a reagent.

The results are presented in Table. one.

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Example2. In the experiments, a sample of surface runoff containing 1325 mg / l of suspended solids and a slurry containing, g / l: CaC 1 (, 5, CaCO3 2.5, and CaO 0.2 was used. Experiments were performed as in Example 1. The results are presented in Table. 2

The experimental data obtained show that with the introduction of pulp in the amount of 20-50 ml per 1 liter of surface wastewater, satisfactory purification results are achieved after daily settling: the content of suspended solids in clarified water does not exceed 30 mg / l with a permissible rate of no more than lO mg / l .

In addition, the advantage of the proposed method of clarifying surface wastewater is that the cleaning process is carried out on standard equipment, according to the simplest technological scheme.

Titanium-magnesium production wastes are used instead of scarce and expensive coagulants.

Table 1

table 2

Claims (2)

Claim 1. The method of clarification of wastewater, including treatment with an alkaline agent to pH 7 "0 * 7.5, the introduction of a powdered agent and a coagulant and the separation of the precipitate, characterized in that, in order to increase the degree of clarification and simplify the method, the treatment is carried out with titanium waste -magnesium production. 2. The method of pop. 1, characterized in that the treatment is waste titanium-magnesium production containing calcium chloride, calcium carbonate and calcium oxide in _4J amounts of 10-20, 2.5 * 3, 0.2-0.3 g / l of waste, respectively, and enter them in the amount of 20-50 mg / l of wastewater.