SU937347A1 - Method for purifying effluents containing ammonium and non-ferrous metal ions - Google Patents

Description

(5) METHOD FOR CLEANING WASTE WATER CONTAINING AMMONIUM IONS AND COLORED METALS

I

The invention relates to methods for the treatment of industrial wastewater containing ammonium ions and non-ferrous metals, and can be used for wastewater treatment in the metallurgical, engineering and chemical industries. ,

A known method for purifying wastewater from the production of lead zirconate titanate containing ammonium ions and heavy metals, including precipitating them as ferrocyanides and co-precipitating the latter with hydroxide and carbonate of iron and calcium 1.

The disadvantages of this method are the complexity of instrumentation, the use of expensive reagents and the impossibility of disposing of valuable components.

The closest to the invention in its technical essence and the achieved result is a method for purifying wastewater containing ammonia from copper ions by treatment with alkali during heating and aeration followed by treatment with calcium chloride 2j.

However, the known method does not provide such a complete treatment of wastewater from non-ferrous metals (residual copper content is 0.5 mg / l), which makes it possible to further utilize the components.

ten

The purpose of the invention is to reduce the residual content of ammonium ions and non-ferrous metals.

The goal is achieved by the fact that according to the method of cleaning

5 wastewater containing ammonium ions and non-ferrous metals, including treatment with alkali during heating and aeration, the aeration is carried out in two stages: the first - at 85 ° C

Claims (2)

20 and the ratio of water-air 1: 200-300 with the distillation of ammonia and subsequent filtering, the second - at 50-60 ° C, the ratio of water-air 1: 1000-2000. In this case, preferably, the first stage of aeration is carried out in a pulsation column at a pulsation intensity of 11000-12000 mm / min. The essence of the method is as follows. In these waste waters, the metals are in solution in the form of complex ammoniates. With an increase in alkalinity with the achievement of certain pH values, the destruction of these Complexes occurs with the formation of metal hydroxides and dissolved ammonia. The completeness of the transition is ensured by the distillation of ammonia from the solution, which, in turn, depends on the surface tension at the phase interface, the difference between the 1 concentrations of ammonia in the solution and the vapor-gas phase, and the temperature of the solution. Minimal surface tension in air bubbles is observed during the formation of a surface film, at which point it occurs at a more intense saturation with ammonia. Subsequent dispersion and coalition of bubbles increases the concentration of ammonia in them. Therefore, the turbulization of the aerated liquid is essential for removal. To optimize the aeration process, the Bonsa-Wilson method is not used at both stages for such factors as water-air ratio, pH value of solutions, temperature, and pulsation intensity. On the basis of the obtained regression equations, the values of the parameters for the first and second stages, respectively, are determined: a water-air ratio of 1 200-300 and 1: 1000-2000, a temperature of 85-95 ° C and 30 -30 ° C, as well as a pulsation intensity of 11000 –12000 mm / mi. Changing the process factors in relation to the values found leads to a deterioration in the quality of cleaning. Example 1 Wastewater containing mg / l: Fe 7200; Si 77} Ni 176; Zn 15,200; Cl-ion 152400; NH 28150, with a pH of 1.5, is treated with lime milk at up to a pH of 11.5. The resulting pulp is aerated at a water-air ratio of 1: 200 in a pulsation column with an intensive pulsation of 11,000 mm / min for 90 minutes, and then filtered. The obtained filtrate is aerated in a distant column at a water-air ratio of 1: 1000 and a temperature of 50 ° C. The result is ammonia water concentration of 23, a solution with content, mg / l :. CaCl2. 255000 i NH 115; Fe 0.50; C 0.10; Ni 0.15; Zn 0.50. P p and M ep 2. Waste water composition similar to example 1, is treated with caustic soda at 95 ° C to pH 12. The resulting pulp is aerated at a water-air ratio of 1: 300 in a pulsation column with a pulsation intensity of 12000 mm / min for 90 min, and then filtered. The obtained filtrate is aerated in a distant column at a water-air ratio of 1: 2000 and a temperature of 60 C. As a result, ammonia water of a concentration of 2k%, solution with the content, mg / l: NaCl 25000; NH-j 105, Fe 0.65; Cu 0.05, -Ni 0.10; Zn 0.60. The use of the proposed method provides, in comparison with the known, a significantly lower residual content of ammonium and nonferrous metals: by MH by times, by C by 4–20 times; Ni 4–200 times, Zn 1000 times. The proposed method allows the utilization of ammonia and solutions of alkali metal salts and ensures the cessation of discharge of highly saline wastewater into the environment. Claim 1. The method of purification of wastewater containing ammonium ions and non-ferrous metals, including treatment with alkali during heating and aeration, characterized in that, in order to reduce the residual content of ammonium ions and non-ferrous metals, aeration is carried out in two stages: first, 85-95C and the ratio of water and air is 1: 200-300, followed by filtration, the second is at 50 ° C and the ratio of water and air is 1: 1,000-2,000. 2. Method 1, which is also distinguished by the fact that the first stage of aeration is carried out in a lulsation column at a pulsation intensity of 11,000-12,000 mm / min. 5E373 76 Sources of information, piezoelectric capacitor taken into account in the examination of materials for electronic equipment, 1 p. P g - 976, p. 18-73. 1. Pashkova I.V., Borovsk R.A. 2. USSR author's certificate. Methods for obtaining and analyzing ferroelectric 5 NSJSIOI, cl. C 02 F, T / 66, 1968.