SU1664758A1 - Method of conditioning ammonia sewage for circulating water supply systems - Google Patents

Abstract

The invention relates to the treatment of water, can be used in the preparation of wastewater in circulating water supply systems and allows you to simplify the process and increase its efficiency while ensuring a similar degree of water stability. Ammoniacontaining wastewater with an organic matter content of not more than 30 mg O ₂ / l for BOD _{5 is} subjected to biochemical treatment in an aerotank for 2 to 3 hours in the presence of nitrifying and heterotrophic microorganisms fixed on fiberglass biocenosis with their ratio (100 - 1000): 1 the ratio of solid and liquid phases in the aero tank 1: (45 - 55). Simplification of the preparation process and improvement of its efficiency are achieved by eliminating the reagent agent, while ensuring a low corrosion rate and the absence of scale formation, as well as eliminating the possibility of water contamination by impurities. 4 tab.

Description

The invention relates to the treatment of water and can be used in the treatment of wastewater for reuse in circulating water systems.

The aim of the invention is to simplify the process and increase its efficiency while ensuring a similar degree of water stability.

In order to carry out the process, ammonia-containing waste water with an organic matter content of not more than 30 mg 02 / l according to BODC is subjected to biochemical treatment in an aeration tank for 2-3 hours in the presence of

the biocenosis of nitrifying and heterotrophic microorganisms fixed on fiberglass with their ratio (100-1000): 1 and the ratio of solid and liquid phases in aeration tank 1 (45-55)

Such process parameters form a biocenosis with the highest concentration I and activity of nitrifying bacteria of phase I, as well as a stable ratio of nitrifying and heterotrophic bacteria, which ensures a high content of nitrites in the water, which are corrosion inhibitors, and a low content of stimulant nitrates

about

ON

-N

vj

SP 00

corrosion. In addition, in the process of treatment, the water from nitrifying bacteria carbonates to bicarbonates is assimilated, resulting in a decrease in the ability of water to boil.

Within 2-3 hours of treatment, the concentrations of nitrites and nitrates are reached, which lower the pH and alkalinity to values that ensure the non-scale operation of the heat exchange equipment. The predominance of nitrite causes the inhibition of metal corrosion. With longer treatment times and a pH of 6.5, the concentration of N02 ionic corrosion inhibitors decreases and the concentration of iono increases, in M03. which reduces the effectiveness of stabilization treatment.

With a treatment time of less than 2 hours, the alkalinity does not allow for the creation of a non-scale regime.

Example. The method is implemented in flow models of aerotanks. Sewage water containing 40 mg / l of ammonium nitrogen, having a BPC of 25 mg / l, alkalinity of 5 mEq / l and pH 8, is fed into four models of aeration tanks and treated for 32.5 h fixed on a solid biocenosis carrier. microorganisms. The mass ratio of the solid and liquid phases is: in the first model of the aeration tank 1:35, in the second model 1:45, in the third 1:55 and in the fourth 1:65. Constant aeration creates an oxygen concentration of 3 mg / l.

The corrosion rate and scaling rate in the treated water, determined on metallic samples by

known methods are presented in table 1.

Tables 2 and 3 present the results of the stabilization treatment of water depending on the duration of the treatment process and the ratio of nitrifying and heterotrophic microorganisms, respectively.

Comparative data on the technical and economic indicators and the effectiveness of the known and proposed methods are presented in Table 4.

The proposed method allows to simplify the process of water preparation and to increase its efficiency by eliminating the reagent agent, while providing a similar degree of protection against corrosion and a higher anti-scaling effect. In addition, it eliminates the possibility of contamination of the treated water with impurities.

Claims (1)

Invention Formula The method of preparation of ammonia-containing wastewater for circulating water supply systems, including biochemical treatment in the aeration tank and the subsequent stabilization treatment, which differs from that. that, in order to simplify the process and increase its efficiency while ensuring a similar degree of water stability, stabilization treatment is carried out in the process of biochemical purification for 2-3 hours in the presence of nitrifying and heterotrophic microorganisms fixed on fiberglass biocenosis with their ratio (100-1000): , the concentration of organic substances is not more than 30 mg 02 / l for BODc and the ratio of solid and liquid phases in the aeration tank 1: (45-55). Table 1 Corrosion rate, G / MATH Scale formation rate, g / m h 0.06 Ots. 0.07 0.04 0.20 0.19 The degree of purification from N-NHy,% ph Alkalinity, mEq / l Corrosion rate, g / m h Scale rate, r / m h 265074989999 7,77,47,27,06,86,5 3.72,41,20,60,30,3 0,240,180,110,050,060,09 0,230,170,200,04От.Отс. Processing Indicators Data at BOD value of treated water, mg / 120 Ratio of nitrifying and heterotrophic bacteria 10: 1 Cleaning degree from N-NH, Z65 Corrosion rate g / m7 h 0.15 Scale formation rate, g / m.h0.25 table 2 Table 3 thirty 100: 1 1000: 1 10000: 1 92 98 98 0.06 0.05 0.03 0.06 0.02 dep. Processing stage: biological treatment introduction of acid administration of a corrosion inhibitor Presence of reagent Reagent consumption, kg / 1000 m of water Scale formation rate, g / m h Corrosion rate, g / m g h Table 4 Available Available m 200 H4SOV 3.0 gmf 9.0 ZnSO "f 4.0 KsCr, 07 0.04 0.06 0.06