CN103241779B

CN103241779B - Preparation method of polyferric sulfate (PFS)

Info

Publication number: CN103241779B
Application number: CN201310215351.XA
Authority: CN
Inventors: 刘转年; 王贵荣; 王艺
Original assignee: Xian University of Science and Technology
Current assignee: Xian University of Science and Technology
Priority date: 2013-05-31
Filing date: 2013-05-31
Publication date: 2015-04-22
Anticipated expiration: 2033-05-31
Also published as: CN103241779A

Abstract

The invention relates to a preparation method of polyferric sulfate (PFS). The method comprises the following steps of dissolving a certain amount of bivalent ferric salt into water; adjusting the pH value through sulfuric acid, and heating and stirring in a water bath; adding a certain amount of persulfate serving as an oxidant to oxidize Fe<2+> in solution; and performing hydrolytic polymerization to obtain PFS. A novel method is provided for the preparation of PFS. The method disclosed by the invention has a simple process; a prepared PFS coagulant has a good coagulation effect and high turbidity removal rate of up to 94.6 percent; moreover, various indexes of the prepared PFS coagulant are consistent with the requirement of PFS serving as a GB14591-2006 water treatment agent; furthermore, the using amount of ferrous sulfate required to be added in the method is small, the adding speed of sodium persulfate serving as an oxidant is easy to control, and ferrous iron is fully oxidized; and moreover, the method has the advantages of simple operating process, no corrosion, wide pH application range, low cost, high performance and a very good market prospect.

Description

A kind of preparation method of bodied ferric sulfate

Technical field

The invention belongs to the studying technological domain of the coagulating agent for trade effluent, municipal effluent and Water purification, particularly a kind of preparation method of bodied ferric sulfate.

Background technology

Coagulating agent is that a kind of fine-grained solids making to disperse in liquid forms the high molecular polymer of throw out, with water arbitrarily than mixing, can be widely used in the process of trade effluent, municipal effluent and feedwater.At present, conventional coagulating agent has aluminium chlorohydroxide, bodied ferric sulfate, iron trichloride and Tai-Ace S 150.Bodied ferric sulfate has the following advantages: it is fast that flocs unit forms speed, particle is closely knit, settling velocity is fast, good removal effect is had for the COD in various waste water, BOD, turbidity, colourity and heavy metal, and to handled waste water ph and water temperature wide accommodation, there is good dehydration property to mud.

Prepare the method mainly direct oxidation method that bodied ferric sulfate is conventional, direct oxidation method mainly contains H ₂o ₂oxidation style, KClO ₃/ NaClO ₃oxidation style, HNO ₃oxidation style and NaClO oxidation style etc., direct oxidation method is high due to the oxygenant price used, and therefore also there are some other problemses in the higher simultaneous reactions process of product cost, as H ₂o ₂oxidation, reaction process is very violent and release a large amount of heat, and high temperature accelerates H ₂o ₂decompose, what be difficult to again reasonably controlled oxidization agent while of wasting to oxygenant adds speed; KClO ₃/ NaClO ₃residual Cl is had in the product of oxidation style ^-and ClO ₃ ^-unsuitable water supply process, and KClO ₃price is more expensive, limits its large-scale commercial production, also can produce a large amount of Cl in reaction process simultaneously ₂, leakage can cause atmospheric pollution; And HNO ₃oxidation style also needs to increase device for absorbing tail gas, and cause device structure complicated, process costs increases.Therefore, the preparation for bodied ferric sulfate still requires further study.

Summary of the invention

In order to overcome bodied ferric sulfate of the prior art preparation method existing for deficiency, the invention provides the preparation method of the bodied ferric sulfate coagulating agent that a kind of preparation technology is simple, coagulation effect good, turbidity removal rate is high.

The present invention solves the problems of the technologies described above adopted technical scheme: take solubility divalent iron salt, the concentration adding water to ferrous ion is 56g/L, the mol ratio adding ferrous ion and persulfate in persulphate to solution is 1:0.1 ~ 1.0, preferred 1:0.4 ~ 0.8,20 ~ 85 DEG C of stirring reactions 0.5 ~ 4 hour, obtain bodied ferric sulfate.

In above-mentioned reaction conditions, preferable reaction temperature is 25 ~ 65 DEG C, and the reaction times is 1 ~ 3 hour.

Above-mentioned solubility divalent iron salt can be FeCl ₂, FeSO ₄and Fe (NO ₃) ₂in any one.

Above-mentioned persulphate is Na ₂s ₂o ₈or K ₂s ₂o ₈.

Can also divalent iron salt water-soluble rear drip in solution sulfuric acid or hydrochloric acid adjustment pH to 3 ~ 7.

The preparation method of bodied ferric sulfate coagulating agent of the present invention is by being dissolved in the water by a certain amount of divalent iron salt, and after adjusting its pH value by sulfuric acid, heating in water bath stirs, and adds a certain amount of persulphate as the Fe in oxidizing solution ²⁺, bodied ferric sulfate (PFS) is obtained through hydrolytic polymerization, preparation for bodied ferric sulfate provides a kind of new method, the coagulation effect of the bodied ferric sulfate coagulating agent that method technique of the present invention is simple and prepared is good, turbidity removal rate is high, can 94.6% be reached, and the indices of prepared bodied ferric sulfate coagulating agent all meets the requirement of GB14591-2006 water conditioner bodied ferric sulfate, in addition ferrous sulfate consumption is added needed for present method few, the speed that adds of oxygenant Sodium Persulfate is easy to control, ferrous iron is substantially oxidized, and operating procedure is simple, non-corrosiveness, pH is applied widely, cost is low, performance is good, there are very good market outlook.

Accompanying drawing explanation

Fig. 1 is that Sodium Persulfate dosage goes the impact of turbid rate to same turbidity water.

Fig. 2 is that temperature goes the impact of turbid rate to same turbidity water.

Fig. 3 goes the impact of turbid rate to same turbidity water in the reaction times.

Embodiment

Existing Binding experiment is further described technical scheme of the present invention, but the present invention is not limited only to the situation of following enforcement.

Embodiment 1

Select ferrous sulfate for solubility divalent iron salt, the method preparing bodied ferric sulfate is: take 13.9gFeSO ₄be positioned in the Erlenmeyer flask of 250mL, add the distilled water of 50mL to FeSO ₄concentration be 56g/L, add 7.14 _gna ₂s ₂o ₈, FeSO ₄with Na ₂s ₂o ₈mol ratio be 1:0.6, ensure Fe in solution ²⁺with S ₂o ₈ ^2-mol ratio be 1:0.6, heating in water bath to 65 DEG C stirring reaction 2 hours, obtains bodied ferric sulfate.

Embodiment 2

Select ferrous sulfate for solubility divalent iron salt, the method preparing bodied ferric sulfate is: take 13.9gFeSO ₄be positioned in the Erlenmeyer flask of 250mL, add the distilled water of 50mL to FeSO ₄concentration be 56g/L, add 4.76g Na ₂s ₂o ₈, FeSO ₄with Na ₂s ₂o ₈mol ratio be 1:0.4,25 DEG C of stirring reactions 3 hours, obtain bodied ferric sulfate.

Embodiment 3

Select ferrous sulfate for solubility divalent iron salt, the method preparing bodied ferric sulfate is: take 13.9gFeSO ₄be positioned in the Erlenmeyer flask of 250mL, add the distilled water of 50mL to FeSO ₄concentration be 56g/L, add 9.52g Na ₂s ₂o ₈, FeSO ₄with Na ₂s ₂o ₈mol ratio be 1:0.8, heating in water bath to 60 DEG C stirring reaction 1 hour, obtains bodied ferric sulfate.

Embodiment 4

Select ferrous sulfate for solubility divalent iron salt, the method preparing bodied ferric sulfate is: take 13.9gFeSO ₄be positioned in the Erlenmeyer flask of 250mL, add the distilled water of 50mL to FeSO ₄concentration be 56g/L, add 1.19g Na ₂s ₂o ₈, FeSO ₄with Na ₂s ₂o ₈mol ratio be 1:0.1,20 DEG C of stirring reactions 4 hours, obtain bodied ferric sulfate.

Embodiment 5

Select ferrous sulfate for solubility divalent iron salt, the method preparing bodied ferric sulfate is: take 13.9gFeSO ₄be positioned in the Erlenmeyer flask of 250mL, add the distilled water of 50mL to FeSO ₄concentration be 56g/L, add 11.9g Na ₂s ₂o ₈, FeSO ₄with Na ₂s ₂o ₈mol ratio be 1:1.0,85 DEG C of stirring reactions 0.5 hour, obtain bodied ferric sulfate.

Embodiment 6

In above-described embodiment 1 ~ 5, take FeSO ₄be positioned in the Erlenmeyer flask of 250mL, add distilled water and dissolve, the pH value dripping moderate amount of sulfuric acid or hydrochloride adjusted solution is 5, adds Na ₂s ₂o ₈, stirring reaction, other operation is identical with corresponding embodiment, obtains bodied ferric sulfate.

Embodiment 7

In above-described embodiment 1 ~ 5, take FeSO ₄be positioned in the Erlenmeyer flask of 250mL, add distilled water and dissolve, the pH value dripping moderate amount of sulfuric acid or hydrochloride adjusted solution is 3, adds Na ₂s ₂o ₈, stirring reaction, other operation is identical with corresponding embodiment, obtains bodied ferric sulfate.

Embodiment 8

In above-described embodiment 1 ~ 5, take FeSO ₄be positioned in the Erlenmeyer flask of 250mL, add distilled water and dissolve, the pH value dripping moderate amount of sulfuric acid or hydrochloride adjusted solution is 7, adds Na ₂s ₂o ₈, stirring reaction, other operation is identical with corresponding embodiment, obtains bodied ferric sulfate.

Embodiment 9

In above-described embodiment 1 ~ 8, raw materials used FeSO ₄the FeCl of equimolar amount can be used ₂or Fe (NO ₃) ₂replace, other raw material, operation and processing condition are identical with corresponding embodiment.

Embodiment 10

In above-described embodiment 1 ~ 8, raw materials used Na ₂s ₂o ₈the K of equimolar amount can be used ₂s ₂o ₈replace, other raw material, operation and processing condition are identical with corresponding embodiment.

In order to verify optimum process condition of the present invention, inventors performed a large amount of experimental verifications, by the dosage of orthogonal experiment to oxygenant, temperature, the parameter such as time and pH is optimized, obtained bodied ferric sulfate (PFS) is processed same turbidity water, observes it separately to the change of the clearance of turbidity, specific as follows:

1) dosage of oxygenant

Take 13.9g ferrous sulfate, add in 250mL Erlenmeyer flask, add distilled water 50mL, the vitriol oil 2, vibration makes ferrous sulfate dissolve rear solution completely for green, add the Sodium Persulfate of different amount, be placed in 65 DEG C of water-baths, turn on agitator, at the uniform velocity stir with the speed of 200r/min, survey it after 2h and turbid rate is gone to the waste water of same turbidity, determine the optimum dosage of oxygenant, see Fig. 1.

As shown in Figure 1, under the same conditions, the bodied ferric sulfate prepared by different Sodium Persulfate dosage is not identical to turbidity removal rate yet, Na ₂s ₂o ₈when being increased to 7.14g from 4.76g, the obtained clearance of bodied ferric sulfate to turbidity has obvious increase, but when being increased to 9.52g, the clearance of bodied ferric sulfate to turbidity declines on the contrary to some extent, also considerably increase the Financial cost of this product simultaneously, therefore can determine that the optimum dosage of oxygenant Sodium Persulfate is 7.14g.

2) temperature of reaction

Take 13.9g ferrous sulfate, add in 250mL Erlenmeyer flask, add distilled water 50mL, the vitriol oil 2, vibration makes ferrous sulfate dissolve rear solution completely for green, add 7.14g Sodium Persulfate, put into 65 DEG C of water-baths, turn on agitator, at the uniform velocity stir with the speed of 200r/min, survey it after 2h and turbid rate is gone to the waste water of same turbidity, determine optimal reaction temperature, see Fig. 2.

As shown in Figure 2, under the same conditions, only temperature of reaction is changed, the turbid rate of going of prepared bodied ferric sulfate also changes thereupon, it increases with the increase of temperature of reaction the clearance of turbidity, but substantially reaches maximum when it is increased to 65 DEG C, therefore can determine that optimal reaction temperature is 65 DEG C.

3) reaction times

Take 13.9g ferrous sulfate, add in 250mL Erlenmeyer flask, add distilled water 50mL, the vitriol oil 2, vibration makes ferrous sulfate dissolve rear solution completely for green, add 7.14g Sodium Persulfate, put into 65 DEG C of water-baths, turn on agitator, at the uniform velocity stir with the speed of 200r/min, survey it in different time sampling and turbid rate is gone to the waste water of same turbidity, determine optimum reacting time, see Fig. 3.

As shown in Figure 3, under the same conditions, only change the reaction times, the turbid rate of going of prepared bodied ferric sulfate also changes thereupon, reaction times, when increasing to 2h by 1h, the clearance of prepared bodied ferric sulfate to turbidity had obvious increase, but when reacted between when extending to 3h, substantially constant to the clearance of turbidity, therefore can determine that optimum reacting time is 2h.

In sum, show that the preferred plan with Sodium Persulfate prepares bodied ferric sulfate is: FeSO by above-mentioned experiment of single factor ₄7H ₂o:Na ₂s ₂o ₈=1:0.6(mol ratio), temperature is 65 DEG C, and the reaction times is 2h.

Now to bodied ferric sulfate (PFS) product prepared by the method according to embodiment 1, detect its performance according to the regulation of standard " GB14591-2006 water conditioner bodied ferric sulfate ", and compare with GB, the results are shown in Table 1.

Table 1 bodied ferric sulfate quality index

Shown by upper table 1 result, the property indices of the bodied ferric sulfate (PFS) prepared by invention is all up to state standards.

Claims

1. the preparation method of a bodied ferric sulfate, it is characterized in that the method is: take solubility divalent iron salt, the concentration adding water to ferrous ion is 56g/L, the mol ratio adding ferrous ion and persulfate in persulphate to solution is 1:0.4 ~ 0.8,25 ~ 65 DEG C of stirring reactions 1 ~ 3 hour, obtain bodied ferric sulfate;

Above-mentioned solubility divalent iron salt is FeCl ₂or Fe (NO ₃) ₂, above-mentioned persulphate is Na ₂s ₂o ₈or K ₂s ₂o ₈.

2. the preparation method of bodied ferric sulfate according to claim 1, is characterized in that: divalent iron salt water-soluble rear drip in solution sulfuric acid or hydrochloric acid adjustment pH to 3 ~ 7.