CN113457639A

CN113457639A - Manganese-loaded loofah sponge fiber for adsorption catalytic denitrification and preparation and application thereof

Info

Publication number: CN113457639A
Application number: CN202110790067.XA
Authority: CN
Inventors: 王宇晖; 许中硕; 黄佳琦; 宋新山
Original assignee: Donghua University
Current assignee: Shanghai Zeyao Environmental Protection Technology Co ltd
Priority date: 2021-07-13
Filing date: 2021-07-13
Publication date: 2021-10-01
Anticipated expiration: 2041-07-13
Also published as: CN113457639B

Abstract

The invention discloses a manganese supported fiber for adsorption and catalytic denitrification and its preparation and application. The invention uses loofah as a raw material, and is modified by mixing with sodium hydroxide, potassium permanganate and manganese sulfate to prepare manganese oxide-loaded loofah fiber. The manganese-loaded loofah fibers with the adsorption and catalytic denitrification are added into wastewater containing ammonia nitrogen, inoculated with sludge, and then aerated and reacted, and the adsorption and degradation of ammonia nitrogen is completed. The preparation method of the invention is simple, the prepared manganese-loaded loofah fiber can efficiently remove ammonia nitrogen in the water body at normal temperature, and the ammonia nitrogen in the water can be quickly adsorbed on the surface of the loofah to achieve the purpose of rapid catalytic degradation. It can be used as a slow-release carbon source for denitrification reactions. The invention is suitable for denitrification treatment of ammonia nitrogen wastewater.

Description

Manganese-loaded loofah sponge fiber for adsorption catalytic denitrification and preparation and application thereof

Technical Field

The invention relates to a manganese-loaded fiber for adsorption catalytic denitrification and preparation and application thereof, belonging to the technical field of water pollution treatment.

Background

Water pollution is one of the most important environmental pollutants. In recent years, with the gradual development of various industries, the problem of waste water discharge has become a key environmental problem, and the random discharge of a large amount of waste water not only poses a serious threat to the ecological environment, but also has a lot of negative effects on the health development of human beings.

Ammonia nitrogen is a typical form of nitrogen pollution of water, and the commonly used denitrification technologies at present comprise air stripping, chemical precipitation, advanced oxidation, biological treatment and the like. But the cost is high, the efficiency is low, and the low ammonia nitrogen wastewater is difficult to treat. Aiming at the problems, the adsorption method is more and more widely applied to the treatment of ammonia nitrogen wastewater, and common adsorbents such as zeolite, biochar and the like have high adsorption capacity, but have the defects of large adsorbent consumption, complex preparation process, long adsorption balance period and the like.

In recent years, manganese has become one of the important elements of interest because of its significant influence on biological denitrification efficiency. Manganese is a ubiquitous metal element in the environment and is also an essential part of microbial activity. The manganese element can participate in the activity of bacterial superoxide dismutase and plays an important role in the synthesis of microbial enzymes in the denitrification process. Meanwhile, the manganese oxide is used as an eco-friendly adsorbent with good adsorption capacity and strong oxidation performance, and has the advantages of simple preparation method, high removal rate, wide application conditions and the like.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the prior commonly used denitrification technology has the problems of high cost, low efficiency and difficult treatment of low ammonia nitrogen wastewater.

In order to solve the technical problems, the invention provides manganese-loaded loofah sponge fiber for adsorption catalytic denitrification, which takes loofah sponge as a raw material and is prepared by mixing and modifying the raw material with sodium hydroxide, potassium permanganate and manganese sulfate.

The invention also provides a preparation method of the manganese-loaded loofah sponge fiber for adsorption catalytic denitrification, which comprises the steps of completely immersing loofah sponge segments in a sodium hydroxide solution, taking out the loofah sponge segments after soaking for 30-120 min, washing to be neutral, and drying; and then soaking the loofah sponge in a manganese sulfate aqueous solution, adding a potassium permanganate solution, placing the obtained reaction system on a shaking table to react at room temperature, taking out the reaction system, and drying to obtain the manganese-loaded loofah sponge fiber.

Preferably, the mass concentration of the sodium hydroxide solution is 1-10%.

Preferably, the washing method specifically comprises: washing with tap water, and then rinsing with deionized water until the rinsing liquid is neutral.

Preferably, the mass ratio of the potassium permanganate to the manganese sulfate is (1-3): (1-3); the ratio of the potassium permanganate to the reaction system is (1-5) g, (200-1000) mL.

Preferably, the loofah sponge is completely soaked in the aqueous solution of manganese sulfate and is subjected to ultrasonic treatment for 10 min.

Preferably, the reaction time is 1-24 h.

Preferably, the drying temperature of the two times is 50-70 ℃, and the drying time is 1-3 hours.

The invention also provides application of the manganese-loaded loofah sponge fiber for adsorption catalytic denitrification in adsorption degradation of ammonia nitrogen in water, and is characterized in that the manganese-loaded loofah sponge fiber for adsorption catalytic denitrification is added into wastewater containing ammonia nitrogen, sludge is inoculated, aeration and reaction are carried out, and ammonia nitrogen adsorption degradation is completed.

Preferably, the manganese-loaded loofah sponge fiber for adsorption catalytic denitrification is used as a filler and placed in a porous structure to prevent the manganese-loaded loofah sponge fiber from being dispersed by water flow, and then the porous structure filled with the filler is placed in a biological filter reactor to enable the wastewater to be treated to pass through the reactor from bottom to top; the aeration is specifically air or oxygen, and the aeration process controls the dissolved oxygen in the water body to be 2-5 mg/L; the addition amount of the manganese-loaded loofah sponge fiber for adsorption catalytic denitrification is as follows: the filling rate (volume) of the biological filter is 30-40%.

According to the invention, manganese oxide is originally generated on the loofah sponge fiber through an oxidation-reduction reaction, the main component of the manganese oxide is manganese dioxide, and the obtained manganese-loaded loofah sponge fiber can efficiently remove ammonia nitrogen in water at normal temperature, so that the ammonia nitrogen in water can be rapidly adsorbed on the surface of the loofah sponge, the purpose of rapid catalytic degradation is achieved, and the efficient treatment of wastewater is realized.

The method has more advantages in treating the nitrogen-containing wastewater by using the loofah sponge fiber loaded manganese oxide as a fixed carbon source for adsorption, catalysis and denitrification. The loofah sponge filler has low manufacturing cost, can be used as a slow-release carbon source to provide nutrition for water microorganisms, and has a remarkable effect of treating nitrogen-containing wastewater by loading manganese oxide on loofah sponge, and short treatment time. The characteristic properties of the modified loofah sponge are changed, and the curing and stabilizing capability of pollutants is improved.

Compared with the prior art, the invention has the beneficial effects that:

(1) the manganese-loaded loofah sponge fiber for adsorption catalytic denitrification, which is prepared by the invention, has a loose and porous spatial structure, is beneficial to quick biofilm formation of microorganisms, and achieves the purpose of quickly starting denitrification reaction.

(2) The manganese-loaded loofah sponge fiber for adsorption catalytic denitrification prepared by the invention has the advantages that the loaded manganese oxide is mainly manganese dioxide, and the properties of the manganese dioxide are not changed before and after the reaction, so that the manganese-loaded loofah sponge fiber can be recycled.

(3) According to the manganese-loaded loofah sponge fiber for adsorption catalytic denitrification, which is prepared by the invention, the loofah sponge carrier can be used as a fixed slow-release carbon source, so that the effect of long-term denitrification is achieved.

(4) For ammonia nitrogen wastewater adsorbed, catalyzed and degraded at normal temperature, the ammonia nitrogen concentration of 1L of initial water sample is 31.2772mg/L, and the COD value is 90.763; after 12 hours, the ammonia nitrogen concentration of the water sample is reduced to 28.1802mg/L, and the COD value is reduced to 64.964; after 24 hours, the ammonia nitrogen concentration of the water sample is reduced to 21.6543mg/L, and the COD value is reduced to 27.091. The degradation rate of ammonia nitrogen is 0.0128 mg/(L.h).

(5) The manganese-loaded loofah sponge fiber for adsorption catalytic denitrification, prepared by the invention, has the advantages of rich source of production raw materials, low price, simple preparation process and mass production.

(6) Compared with the traditional denitrification method, the adsorption and catalytic denitrification manganese-loaded loofah sponge fiber prepared by the invention combines the adsorption denitrification with a biological method, and is more energy-saving, efficient and lower in cost.

Drawings

FIG. 1 is an SEM image of manganese-loaded loofah sponge fibers for adsorption catalytic denitrification in example 1;

fig. 2 is an SEM image of the manganese-supported loofah sponge fiber for adsorption catalytic denitrification in example 2.

Detailed Description

In order to make the invention more comprehensible, preferred embodiments are described in detail below with reference to the accompanying drawings.

Example 1

(1) Cutting retinervus Luffae fructus into 1cm × 1cm segments, soaking in 1.5% sodium hydroxide solution for 30min, taking out, washing with tap water, and rinsing with deionized water until the rinsing solution is neutral to obtain alkali modified retinervus Luffae fructus.

(2) Weighing 1g of manganese sulfate, completely dissolving in 100mL of deionized water, adding 2g of alkali modified loofah sponge, and carrying out ultrasonic treatment for 10 min. Then, 100mL of a 10g/L potassium permanganate solution was added dropwise thereto, and the mixture was placed on a shaker at 100rpm and reacted at room temperature for 24 hours. And aging the mixture for 4 hours, taking out, and putting the mixture into a blast drier to be dried for 3 hours at the temperature of 60 ℃ until the weight is constant, thus obtaining the manganese-loaded loofah sponge.

(3) Weighing 2g of manganese-loaded loofah sponge fiber for adsorption catalytic denitrification, filling the manganese-loaded loofah sponge fiber into a semicircular porous sphere processed by polyethylene, polypropylene and other materials, measuring 1L of distilled water, adding ammonium chloride to prepare test water with the ammonia nitrogen concentration of 20mg/L, inoculating 3.5g/L of activated sludge, controlling the dissolved oxygen in the water to be 2-5mg/L by aeration, and measuring the ammonia nitrogen concentration after 3h, 6h, 9h, 12h and 24h respectively.

Fig. 1 is an SEM image of manganese-supported loofah sponge fibers for adsorption catalytic denitrification in example 1. Table 1 is a table of the degradation data for ammonia nitrogen for example 1.

Table 1 degradation data for ammonia nitrogen in example 1

Time (h)	0	3	6	9	12	24
							Ammonia nitrogen concentration (mg/L)	31.2772	31.8856	29.3416	29.3416	28.1802	21.6543

Example 2

(3) Weighing 2g of manganese-loaded loofah sponge fiber for adsorption and catalytic denitrification, filling the manganese-loaded loofah sponge fiber into a semicircular porous sphere processed by polyethylene, polypropylene and other materials, measuring 1L of distilled water, adding ammonium chloride to prepare test water with ammonia nitrogen concentration of 20mg/L, inoculating 3.5g/L of activated sludge, controlling dissolved oxygen in the water to be 2-5mg/L by aeration, and measuring COD (chemical oxygen demand) values after 3h, 6h, 9h, 12h and 24h respectively. Fig. 2 is an SEM image of the manganese-supported loofah sponge fiber for adsorption catalytic denitrification in example 2. Table 2 shows the degradation data of example 2 for COD.

Table 2 degradation data for COD in example 2

Time (h)	0	3	6	9	12	24
							COD(mg/L)	90.763	43.704	109.410	82.987	64.964	27.091

Claims

1. a manganese-loaded loofah fiber for adsorption catalysis denitrification, is characterized in that, described manganese-loaded loofah fiber takes loofah as raw material, and is modified by mixing with sodium hydroxide, potassium permanganate and manganese sulfate, and is prepared. A manganese oxide-loaded loofah fiber was obtained.

2. the preparation method of the manganese-loaded loofah fiber of adsorption catalytic denitrification according to claim 1, is characterized in that, the loofah segment is completely immersed in sodium hydroxide solution, take out after soaking 30～120min, and wash to medium Then soak the loofah in an aqueous solution of manganese sulfate, then add potassium permanganate solution, place the obtained reaction system on a shaker at room temperature to react, take out, and dry to obtain manganese-loaded loofah fibers.

3. The preparation method according to claim 2, wherein the mass concentration of the sodium hydroxide solution is 1-10%.

4. The preparation method according to claim 2, characterized in that, the washing method is specifically: firstly rinsing with tap water, and then rinsing with deionized water until the rinsing liquid is neutral.

5. preparation method as claimed in claim 2 is characterized in that, the mass ratio of described potassium permanganate and manganese sulfate is (1～3): (1～3); Described potassium permanganate and reaction system The ratio of (1～5) g: (200～1000) mL.

6. preparation method as claimed in claim 2, is characterized in that, described loofah is soaked in the aqueous solution of manganese sulfate for complete soaking and ultrasonic 10min.

7. The preparation method of claim 2, wherein the reaction time is 1-24 h.

8 . The preparation method according to claim 2 , wherein the drying temperature is 50-70° C. for both times, and the drying time is 1-3 h. 9 .

9. the application of the manganese-loaded loofah fiber of the adsorption-catalytic denitrification of claim 1 in the adsorption and degradation of ammonia nitrogen in water, it is characterized in that, the manganese-loaded loofah fiber of the described adsorption-catalytic denitrification is added to the loofah containing In the wastewater of ammonia nitrogen, the sludge is inoculated, then aerated and reacted, and the adsorption and degradation of ammonia nitrogen is completed.

10. The application according to claim 9, characterized in that, the manganese-loaded loofah fiber of the adsorption catalytic denitrification is placed in the porous structure as a filler to prevent it from being washed away by water flow, and then the filler-loaded loofah fiber is placed in the porous structure as filler. The porous structure is placed in the biological filter reactor, so that the wastewater to be treated passes through the reactor from bottom to top; the aeration is specifically the introduction of air or oxygen, and the aeration process controls the dissolved oxygen in the water body to 2-5mg/L; The added amount of the manganese-loaded loofah fiber for adsorption and catalytic denitrification is as follows: the filling rate of the biofilter reactor is 30% to 40%.