RU2293968C2 - Method of measuring of dirt retention of water-cleaning filter - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: light transmission coefficient is measured periodically in water samples taken at input of filter and at output of filter at wavelength of λ being equal to 210-254 nm. Amount of impurities is found in base of calibration dependence of light transmission coefficient on content of iron impurities in aqueous solution or calibration dependence is used which light transmission coefficient in relation to content of total organic nitrogen in aqueous solution.

EFFECT: improved truth of results; reduced time cost for realization.

2 dwg

Description

The invention relates to chemistry, in particular to water purification in water treatment plants, and can find application in determining the contamination of iron impurities of mechanical filters or natural organic compounds of anion exchange filters in water purification, in particular, in the processes of clarification or ion exchange.

A known method for determining the contamination of a mechanical filter with metal compounds, in which periodic measurements of at least one parameter characterizing the composition of water are carried out, in water samples taken at the inlet and outlet of the filter, the difference in the values of this parameter is determined from this difference in values determine the amount of metal impurities ΔMe in the filter in a specific measurement, while the total number of metal impurities Me in the filter is determined by the following relationship:

Me = ∑ΔMe · Q _n , and as a parameter characterizing the composition of water, use the change in transmittance Δk, the values of which are determined at λ = 340 ÷ 450 nm, and the content of metal impurities in a particular measurement is determined by the following dependence:

ΔМе = а · Δk,

where a is the proportionality coefficient determined experimentally, mg /% · dm ³ ;

ΔMe is the amount of metal impurities in a particular measurement, delayed by the loading of a mechanical filter, kg, t;

ΔMe = Me _in. -Me _O, kg / ton;

Me _in. - metal content in water at the entrance to the mechanical filter, kg / t;

Me _out. - metal content in water at the outlet of the mechanical filter, kg / t;

Me is the total amount of metal impurities in the filter per filter cycle, kg;

λ is the wavelength, nm;

n is the total number of measurements;

Q _n - the amount of water passed through a mechanical filter in the period between measurements, t;

k _input - transmittance at the entrance to the mechanical filter,%;

k _out. - transmittance at the exit of the mechanical filter;

Δk - change in transmittance: Δk = k _out. -k _in. , % [one].

The method described in [1] for determining the contamination of a mechanical filter with metal compounds makes it possible to determine the contamination of a mechanical filter by the express method with an iron content in a suspended, finely divided state of more than 0.2 mg / dm ³ . However, the products of iron corrosion are contained in an amount from 0.2 to 0.02 mg / dm ³ ; therefore, the method described in [1] for determining the contamination of a mechanical filter with metal compounds can be applied only to mechanical filters with an iron content of 0.2 mg / dm ³ and more, and is not applicable on filters of other species, in particular on anion exchangers to determine the contamination of the latter with natural organic compounds.

The invention solves the problem of creating a method for determining the contamination of a mechanical filter for water purification with impurities of iron or an anion exchange filter - natural organic compounds, characterized by wide functionality with high reliability of the results and minimal time spent on implementation.

,To solve the problem in a method for determining the contamination of a filter for water purification, in which periodic measurements of the light transmission coefficient k in water samples taken at the inlet and outlet of the filter are carried out, the amount of impurities P in the filter is determined, the values proposed according to the present invention the light transmission coefficient k to determine at a wavelength λ equal to 210 ÷ 254 nm, the amount of impurities ΔP to determine based on the calibration dependence of the light transmission coefficient on the content impurities in an aqueous solution, using the calibration dependence of the light transmission coefficient on the content of iron impurities in the aqueous solution or the calibration dependence of the light transmission coefficient on the total organic carbon content in the aqueous solution, and determine the total amount of impurities P in the filter by the following dependence:

,

where ΔP - the amount of impurities of iron or natural organic compounds in a particular measurement, delayed by the load of the filter, kg / t;

ΔP = P _in. -P _out. kg / t;

P _in. - the content of impurities of iron or natural organic compounds in the water at the inlet to the filter, kg / t;

P _out. - the content of impurities of iron or natural organic compounds in the water at the outlet of the filter, kg / t;

P - the total amount of impurities of iron or natural organic compounds in the filter per filter cycle, kg;

n is the total number of measurements;

Q _n - the amount of water passed through the filter in the period between measurements, t.

The invention is illustrated by the drawings: FIGS. 1 and 2, which show the dependences of the light transmittance on the impurity content at different wavelengths λ, in particular, FIG. 1 shows the dependence of the light transmittance k on the content of iron impurities in an aqueous solution at a wavelength λ of 210 nm, figure 2 presents the dependence of the transmittance k on the content of total organic carbon in aqueous solution at a wavelength λ equal to 254 nm.

The possibility of determining impurities P (iron, natural organic compounds) is described in detail in the relevant literature, for example, [2-4].

Means and methods by which it is possible to build the calibration dependence necessary for the implementation of the invention are described in detail in [5].

The invention is also illustrated by the results of experimental data for determining the contamination of the filter for water purification, summarized in tables. In particular, Table 1 presents the experimental data for determining the contamination of a mechanical filter for water purification with iron impurities, and Table 2 presents the experimental data for determining the contamination of an anionite filter with natural organic compounds.

The data on the content of iron impurities in the aqueous solution presented in column 5 of table 1 were obtained experimentally based on the traditional chemical analysis method, and the data presented in column 11 of this table were obtained using the calibration dependence presented in figure 1 at a wavelength λ equal to 210 nm. The light transmission coefficients at the input and output (column 9) were measured, based on the calibration dependence, the iron content was determined, and the values of П and ΔП were calculated.

A comparison of the results of the estimated contamination of the mechanical filter by the content of iron impurities allowed us to conclude that the proposed method is operable and its application in determining the contamination of the mechanical filter with iron impurities when their content is from 0.28 to 0.07 mg / dm ³ .

Table 1
Experimental data for determining the contamination of a mechanical filter with iron compounds Sample number Q, thousand tons Fe, μg / dm ³ P, g / t entrance Exit ΔP, g / t P, g / t entrance exit ΔP, g / t k (210)% Fe, μg / dm ³ k (210)% Fe, μg / dm ³ one 2 3 four 5 6 7 8 9 10 eleven 12 MF №1 260 148 112 77 264 86 140 124 10 230 120 110 1100 79 238 87 126 112 1120 fifteen 234 134 one hundred 500 79 238 87 126 112 560 twenty 262 132 130 650 77 264 87 126 138 690 25 232 125 107 535 79 238 87 126 112 560 thirty 256 95 161 805 78 252 89 98 154 770 35 230 110 120 600 80 224 88 112 112 560 40 228 120 108 540 80 224 87 126 98 490 45 208 109 101 505 81 210 88 112 98 490 Pollution (P) 5235 Pollution (P) 5240 MF №11 5 260 210 fifty 250 77 264 81 210 54 270 10 304 182 122 610 75 292 83 182 110 550 fifteen 260 130 130 650 77 260 87 126 134 670 twenty 264 132 132 660 77 264 87 126 138 690 25 255 122 133 665 78 252 87 126 126 630 thirty 265 134 131 655 77 264 86 140 124 620 35 285 136 149 745 75 292 86 140 152 760 Pollution (P) 4235 Pollution (P) 4190 MF №12 5 260 200 60 300 77 264 81 210 54 270 10 304 180 124 620 75 292 83 182 110 550 fifteen 276 152 124 620 76 278 87 126 152 760 twenty 264 132 132 660 77 264 87 126 138 690 25 255 126 129 645 78 252 87 126 126 630 thirty 265 166 99 495 77 264 84 168 96 480 35 285 138 147 735 75 292 86 140 152 760 Pollution (P) 4075 Pollution (P) 4140 Note: column 6 = column 5 · column 2; gr. 12 = gr. 11 · gr. 2.

Table 2 presents the results of determining the content of organic compounds based on the obtained values of the light transmittance k _c at the input and output of this filter, and Fig. 2 shows a calibration dependence for determining the total organic carbon content from the light transmittance k _c at a wavelength λ = 254 nm.

The determination of total organic carbon, carried out on special instruments, is quite expensive and time-consuming and cannot be used to determine the total organic carbon content with its content less than 1.

table 2
Experimental data on the determination of contamination of the anion exchange filter by natural organic compounds Water consumption, Q, t Experimental and calculated data entrance exit C (calc.), G (P) k (10),% C mg / L (P _in ) k,% C mg / L ( _Pout ) OH-1-4 (AN-31, V charged = 14.13 m ³ ) 1770 85 7 90 0.4 11682 3170 86 6 88 0.5 7700 4950 87 6 90 0.4 9968 6680 87 6 82 0.9 8823 8330 86 6 89 0.4 9240 9810 87 6 88 0.5 8140 11330 85 7 90 0.4 10032 12950 86 6 88 0.5 8910 Organic filter impurities per 1 filter cycle 74495 4335 85 7 86 0.6 27744 5895 87 6 85 0.7 9984 7995 85 7 86 0.6 11130 9655 87 6 82 0.9 10624 11875 86 6 82 0.9 11322 13715 86 6 82 0.9 9384 Organic filter impurities per 2 filter cycles 80188 OH-1-2 (MP-64, Vload = 13.06 m ³ ) 1460 86 6 90 0.4 8176 3380 82 9 90 0.4 16512 5195 85 7 84 0.7 11434.5 6885 86 6 87 0.6 9126 Total for 3 filter cycles 45,248.5

The inventive method for determining the contamination of the filter for water purification allows the example of determining the contamination of the anion exchange filter with natural organic compounds by relatively simple methods to determine the contamination of the specified filter. It is enough to have a pre-constructed dependence of the transmittance on the content of total organic carbon. The implementation of the proposed method is especially important when developing diagnostic systems in the operational modes of these filters, because their operation is associated with a significant consumption of water for washing the material.

The inventive method for determining the contamination of the filter for water purification: a mechanical filter with impurities of iron, and an anion exchange filter with natural organic compounds was tested experimentally at JSC Sverdlovenergo. The results of the verification showed the efficiency of the method, as well as the wide possibilities of practical implementation due to its relative simplicity. In addition, this method can be the basis of both manual and instrument control.

Literature

1. RF patent 2224578, IPC B 01 D 35/143, G 01 N 21/17, 2004

2. A.T. Pilipenko, I.V. Pyatnitsky. Analytical chemistry: Book 1. M., Chemistry, 1990, p.321.

3. Yu.A. Zolotev, E. N. Dorokhova, V. I. Fadeev, and others. Fundamentals of analytical chemistry. Book 2. Methods of chemical analysis. Textbook for high schools - 2nd ed., M., Higher School, 2002, p.276.

4. I.I. Grandberg. Organic chemistry: A textbook for university students enrolled in agronomic specialties, 4th ed., M., Bustard, 2001, p. 108.

5. "Water-chemical regimes and water treatment at TPPs" // Scientific and technical seminar. - M .: VTI OJSC, 2004, p.5-17.

Claims (1)

A method for determining the contamination of a filter for water purification, in which periodic measurements of the light transmission coefficient k in water samples taken at the inlet and outlet of the filter are carried out, the amount of impurities P in the filter is determined, characterized in that the light transmission coefficient k is determined at the wavelength λ equal to 210-254 nm, the amount of impurities ΔP is determined on the basis of the calibration dependence of the light transmission coefficient on the content of impurities in the aqueous solution, using intramural dependency coefficient of light transmission of the content of iron impurity in an aqueous solution or calibration curve of light transmission factor of the total organic carbon content of the aqueous solution, and the total amount of impurities P located in the filter is determined by the following relationship:

where ΔP - the amount of impurities of iron or natural organic compounds in a particular measurement, delayed by the load of the filter, kg / t; ΔP = P _in. -P _out. kg / t P _in. - the content of impurities of iron or natural organic compounds in the water at the inlet to the filter, kg / t; P _out. - the content of impurities of iron or natural organic compounds in the water at the outlet of the filter, kg / t; P - the total amount of impurities of iron or natural organic compounds in the filter per filter cycle, kg; n is the total number of measurements; Q _n - the amount of water passed through the filter in the period between measurements, t.

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