JPH01139190A - Hydrogen sulfide remover - Google Patents

Abstract

PURPOSE:To reduce amount of a chemical agent and to enhance the removal of hydrogen sulfide by using mixed liquid of both an electrolyte soln. incorporating trivalent iron ion and an electrolyte soln. incorporating bivalent copper ion as a hydrogen sulfide remover. CONSTITUTION:A hydrogen remover is prepared by mixing an electrolyte soln. incorporating trivalent iron ion, e.g., a ferric chloride soln. with an electrolyte soln. incorporating bivalent copper ion, e.g., a cupric chloride soln. When adding this hydrogen sulfide to, e.g., drainage of a paper mill, generated hydrogen sulfide is oxidized by trivalent iron ion and changed into sulfur and also it is oxidized by bivalent copper ion and changed into copper sulfide. Therefore, since one part of hydrogen sulfide is removed by copper ion, the residual part to be removed by iron ion is made little and therefore hydrogen sulfide can be sufficiently removed even when introduction amount of iron is reduced.

Description

[Detailed description of the invention] A. Industrial application field The present invention relates to a hydrogen sulfide removal agent.

B. Prior Art Factory wastewater often contains various pollutants, and means are needed to remove them. Hydrogen sulfide gas is one of them, and is generated, for example, from wastewater and sludge in paper mills, and if left untreated, problems such as environmental pollution and equipment corrosion will occur.

Conventional methods for removing hydrogen sulfide include sodium hypochlorite (NaCIO), ferric chloride (FeC13), ferric sulfate (Fe, (SOa) 3), polyiron (F
There is a method of oxidizing hydrogen sulfide and fixing it as sulfur using an oxidizing agent such as He had been hired.

CI O-+ HpS-Ct-+ H2O+ S↓・・
・(1) 2Fe"+H2S→2Fe"+214"+S↓
・= (,2) Problems to be solved by the C2 invention However, since the above-mentioned wastewater and sludge contain a large amount of organic matter, a large amount of the oxidizing agent is used for oxidizing and decomposing the organic matter. The efficiency of the removal rate of hydrogen sulfide by the oxidizing agent itself decreases, and even though a large amount of the oxidizing agent is required, hydrogen sulfide cannot be removed sufficiently.

This means that, for example, the amount of waste water in a paper mill is 5 to 50% per day.
120,000, which is causing drug costs to skyrocket. Furthermore, since the pH range in which a high reaction rate can be obtained is narrow, processing operations are troublesome.

Further, when a trivalent iron-based compound is used as an oxidizing agent, there are the following problems. That is, as mentioned above, since the removal rate of hydrogen sulfide is low and the amount of iron-based oxidizing agent input is large, when organic compounds and hydrogen sulfide reduce trivalent iron ions, a large amount of ferrous hydroxide (Fe (OH)z) is generated. This ferrous hydroxide reacts with dissolved oxygen in the air and wastewater to form hydrated ferric oxide (Fe vos ・n HtO), but hydrated ferric oxide has a weak flocculation effect, so it cannot be formed into a colloidal solution. As a result, the discharged water becomes a problem.

The purpose of the present invention is to solve these problems, to reduce the amount of chemicals and reduce costs, and to obtain a high hydrogen sulfide removal rate, as well as to reduce the turbidity of wastewater. The purpose of the present invention is to provide a hydrogen sulfide removal agent that can remove hydrogen sulfide.

Means and Effects for Solving Problem D1 The hydrogen sulfide removing agent of the present invention is an electrolyte solution containing trivalent iron ions, such as a ferric chloride solution, and an electrolyte solution containing divalent copper ions, such as a cupric chloride solution. It consists of a mixture of

When such a mixed solution is added to wastewater from a paper mill, for example, the generated hydrogen sulfide is oxidized by trivalent iron ions to sulfur, and then oxidized by divalent copper ions to copper sulfide (CuS). Become.

Therefore, since some of the hydrogen sulfide is removed by copper ions, the remaining amount to be removed by iron ions is reduced.
Therefore, hydrogen sulfide can be sufficiently removed even if the amount of iron ions introduced is reduced.

As a result, the amount of iron ions required is reduced, and even if the amount of copper ions added is included, the total amount of drug input is reduced. Since a large amount of trivalent iron ions remain and a portion of hydrogen sulfide is removed by copper ions, the amount of ferrous hydroxide produced is suppressed and the next product, hydrated ferrous oxide, is suppressed. The amount of diiron produced also decreases, resulting in less turbidity, and the residual trivalent iron ions can also be expected to have a flocculating effect. In addition, since the production rate of copper sulfide is high over a wide pH range, desulfurization is covered by copper ions even in the pH range where the reaction rate by iron ions is not so high, so in the end, desulfurization is covered by the pI-1 region where substantial effects can be obtained. is wider than before.

E. Example The effectiveness of the hydrogen sulfide removing agent of the present invention was evaluated as follows by supplying wastewater from a paper mill to a tallifier and treating the resulting supernatant water and sludge through solid-liquid separation. I looked it up.

(1) Experimental method As shown in Figure 1, drain liquid (supernatant water or sludge) is sampled for 100 m (100 m) into a 200 x (200 x sampling container 1) and a predetermined 1! (0 to 101,000 pp) chemical solution (
Hydrogen sulfide remover) was added, the pH was adjusted to 5.3 with sodium hydroxide or sulfuric acid, the cap was tightly sealed, the mixture was stirred for 1 minute using magnetic stirrer 2, and then the thermostatic bath 3 was added.
Keep the inside warm at 40℃ and leave for 1.5 hours. After stirring for 1 minute, gas was sampled from the sampling tube 4 while stirring was continued, and the hydrogen sulfide concentration was measured by the detection tube method.

(2) Experimental results The hydrogen sulfide agent of the present invention has a component ratio of Fe, 03 and 4.
Ferric chloride (Fe
Cl2) solution and cupric chloride (CuC1t) solution, and in order to further relatively evaluate the present invention, polyiron (Fe (SO4) t-n(0H)1-n) solution and the following Similar tests were conducted using each of the sodium chlorite (NaCIO) solutions as chemical solutions. Table 1 shows the results when the sludge in the factory wastewater was treated, and Table 2 shows the results when the supernatant water was treated. However, regarding the indication of the type of chemical solution, the hydrogen sulfide agent of the present invention is (Fe'°).

Cu” type) Sodium hypochlorite (available chlorine 12%)
is expressed as NG.

Table 1 Table 2 (3) Discussion When treating factory effluent sludge, as seen from Table 1, when the amount of chemical added was 500 ppm, (Fe3°,
The hydrogen sulfide concentration is approximately 0 for (Cu" series), but it is contained in polyiron and NG of 1100 pp or more, and (F e ",
The amount of additive (Cu ” system) is about half that of polyiron and NC. When treating the supernatant water of factory effluent, as shown in Table 2, (Fe ”, Cu ” ° system) The hydrogen sulfide concentration can be reduced to 0 with an addition amount of 5 ppm, whereas for polyiron and NC, hydrogen sulfide remains even with an addition amount of 20 ppm.From these results,
It is understood that the hydrogen sulfide removal agent of the present invention has a much higher removal efficiency than conventional chemical solutions.

F. Effect According to the present invention, since it contains trivalent iron ions and divalent copper ions, it will be explained in detail in the section "Means and effects for solving the D0 problem", and the experimental results will be explained in detail. As evidenced by the above, hydrogen sulfide removal efficiency is high, and the amount of chemical solution required is small, so costs can be kept low.

Since the input amount of the chemical solution is small, the production of hydrous ferric oxide 1 is also reduced, and the turbidity of the discharged water is reduced. Furthermore, since the pH range in which substantial results can be obtained is expanded, processing operations become simpler. In the above case, when only an electrolyte containing divalent copper ions is used, the amount of copper sulfide, which is a fine powder with no aggregation effect, increases, resulting in the problem of an increase in carryover of fine powder fireflies. It will happen.

[Brief explanation of the drawing]

FIG. 1 is a side view showing a test apparatus for examining the efficacy of the present invention. 1... Sampling container, 2... Magnetic stirrer, 3... Constant temperature chamber, 4... Sampling tube. Figure 1 Fireflies placed in the public and private sectors with a concave surface

Claims (1)

[Claims] A hydrogen sulfide removal agent consisting of a mixed solution of an electrolyte solution containing trivalent iron ions and an electrolyte solution containing divalent copper ions.