CN101343111B - Method for improving efficiency of attached growth wastewater treatment biomembrane reactor - Google Patents

Abstract

The invention discloses a method for improving the efficacy of an apposition growth wastewater treatment biomembrane reactor. According to the filler type of microorganism apposition growth, 1 to 10mg/kg of rare earth compound (base material of filler) is added to the filler production by computing the dosing quantity, so as to manufacture carriers such as modified fillers or filter materials; and the modified fillers are filled in the biomembrane reactor for wastewater treatment. The time for forming a mature biomembrane can be advanced by five to ten days by using the method, meanwhile, themicroorganism activity and stability are improved, the COD removal rate in wastewater can be increased by 5 percent to 15 percent, and the removal rate of other major pollutants can be raised by 5 percent to 10 percent. The method can effectively accelerate the startup of the wastewater treatment biomembrane reactor, and can obviously improve the purification effect and stability, and the dosing quantity of rare earth is less, the wastewater treatment cost is low, and the application prospect is broad.

Description

A method for improving the efficiency of attached growth wastewater treatment biofilm reactor

technical field

The invention relates to a method for improving the performance of a biofilm reactor for attaching and growing wastewater, in particular to a method for improving the performance of a wastewater biofilm reactor using microorganisms to attach and grow as a carrier.

Background technique

Biological treatment technology includes two categories: attached growth biofilm technology and suspended growth (sludge) technology, which has become one of the leading technologies for wastewater treatment. Biofilm technology has been developed rapidly. Attachment growth technology refers to the growth and reproduction of microorganisms such as bacteria and micro-animals such as protozoa and metazoans attached to certain material carriers to form biofilms. Sewage is fully contacted with biofilms. Among them, the organic pollutants are taken up or decomposed by the organisms in the nutrient film to purify the sewage. Because the biofilm technology attached to the growth of the microbial film has a long food chain in the microbial ecosystem and a good purification effect of the pollutants, it has been widely used. Biofilm reactors, including biological moving bed, biological turntable, biological filter, biological fluidized bed, biological grid, etc., which are fixed by microbial attachment and growth, have been rapidly developed and applied in wastewater treatment engineering, which determines whether the treatment system is stable or not. The key factors for operation are whether the reactor can start up quickly and have a high treatment effect.

Trace elements are important basic substances for maintaining and promoting microbial enzyme metabolic reactions. All microorganisms need metal elements for growth. The existence and bioavailability of trace metals will solve most of the operational problems. The current research in this area is based on the effect of iron, cobalt, nickel, copper, zinc, manganese, molybdenum, tungsten and other elements on the microorganisms in the activated sludge system under low dosage conditions, and the effect of heavy metal ions on the microorganisms in the activated sludge wastewater treatment system. The promotion of population activity has achieved ideal research results. The absence of any one of the common trace metals can cause the inhibition or even stop of the biological treatment reaction and cause the operation to fail. As a class of metals, rare earths are uniquely rich resources in my country. Since the 1980s, the development and application of rare earth resources in my country have spread throughout the fields of industry, agriculture, medical care and life. After years of research and accumulation, it is found that light rare earths such as lanthanum and cerium, which account for three-quarters of the total rare earths, can significantly promote the activity of microorganisms in wastewater treatment systems.

The mechanism of action of rare earths on microorganisms mainly includes two aspects. First, the microbial cell membrane is used as the target organ to interact with biological macromolecules such as proteins and enzymes, thereby affecting certain biological functions and activities of cells. The current research results have found that rare earths can act on transport proteins or phospholipids on cell membranes to improve membrane permeability. Secondly, the active chemical properties and strong complexing ability of rare earth elements determine that they may become harmful free radical scavengers in microorganisms under certain conditions. For example, the existing research results have shown that low concentrations of rare earths have a positive effect on improving biological activity, an appropriate concentration of Ce ³⁺ has a short-term effect on the specific methanogenic activity (SMA) of anaerobic microorganisms, and 0.05 mg/L is effective for stable cultivation. The SMA of anaerobic microorganisms has obvious promotion effect, as high as 14.29%. So far, there are no public reports on the effect of rare earths on microorganisms in wastewater treatment reactors. The patent (publication number CN1654365A) of the method for promoting the activity of anaerobic sludge by using rare earth discloses the method for promoting the activity of anaerobic sludge by using rare earth. However, there is no report on the method of using rare earths to make fillers and promote the purification effect of biofilm reactors.

Contents of the invention

1. The technical problem to be solved by the invention

Aiming at the unstable operation, fast start-up and poor treatment effect of biofilm reactors in wastewater treatment projects, the purpose of the present invention is to provide a method for improving the efficiency of microbial attachment growth wastewater treatment biofilm reactors, which can accelerate wastewater treatment biofilm The start-up of the reactor improves the purification effect and stability.

2. Technical solution

The purpose of the present invention is achieved through the following technical solutions:

A method for improving the performance of biofilm reactors for microbial attachment and growth wastewater treatment, comprising the following steps:

Step A: Adding 1 to 10 mg/kg (filler base material) of soluble rare earth compounds as additives to carriers such as fillers or filter materials when manufacturing carriers such as fillers or filter materials to form modified fillers or modified filter materials;

Step B: filling the above modified filler or modified filter material carrier into a biofilm reactor for wastewater treatment.

Appropriate rare earth compounds are used in the production of modified fillers or filter materials. During the initial film formation process of wastewater treatment reactors, the inoculated and grown microorganisms have a certain growth-stimulating effect.

The rare earth compound additive in the present invention can be a single rare earth or a compound rare earth. The rare earth compound may be a nitrate or chloride rare earth compound.

Carriers such as fillers and filter materials in the present invention can be made of polyethylene, polyvinyl chloride, polystyrene, polypropylene plastics or nylon, vinylon, acrylic, polyester chemical fiber materials.

The reactor applicable to the present invention includes biological moving bed, biological turntable, biological filter, biological fluidized bed and biological barrier.

3. Beneficial effect

The invention provides a method for improving the performance of biofilm reactors for microbial attachment and growth wastewater treatment. The start-up of biofilm reactor for wastewater treatment is guaranteed, and the purification effect and stability can be obviously improved, while the rare earth dosage is small, the cost of wastewater treatment is low, and it has broad application prospects. Using the bio-modified microbial attachment growth immobilization material of the method of the present invention, the mature biofilm time can be advanced by 5 to 10 days, and at the same time the microbial activity and stability can be improved, and the COD removal rate in the wastewater can be increased by 5% to 15%. The removal rate of other major pollutants can be increased by 5% to 10%.

Detailed ways

The present invention will be described in further detail below through practical examples.

Example 1

Adding rare earth nitrate to produce modified suspension packing, the addition amount is Ce(NO ₃ ) ₃ of 5 mg/kg (filler base material), and putting the manufactured modified polyvinyl chloride packing into a moving bed biofilm reactor to treat pharmaceutical wastewater , using the sludge from the aeration tank of a sewage treatment plant as the inoculum sludge to start film formation at room temperature (20-30°C), the initial influent COD concentration was 500mg/L, and nutrients were added normally. After 22 days of start-up operation, The designed COD volume load is 0.8kg/m ³ ·d. Compared with the addition of unmodified filler, the start-up is reduced by 7 days, and the COD removal rate is increased by 5% to 8% after the start-up is completed.

Example 2

Add rare earth chloride to produce modified biological turntables, the amount of which is 2mg/kg (filler base material) CeCl ₃ /LaCl ₃ composite additives, the modified polyethylene and polypropylene plastic biological turntables manufactured are used to treat urban sewage, The sludge from the aeration tank of an urban sewage treatment plant was used as the inoculation sludge to start film formation at room temperature (20-30°C). The initial influent COD concentration was 250-350mg/L, and nutrients were added normally. The start-up time of film formation was 12 day, to reach the design COD volume load of 1.0-1.2kg/m ³ ·d, compared with fillers without rare earths, the start-up is reduced by 5 days, and the removal rate of the matrix is increased by 5%-8% after the start-up is completed.

Example 3

Add compound rare earth compound to produce modified biological rope filler, its addition is 6mg/kg (filler base material) compound rare earth compound (55%～65% Ce(NO ₃ ) ₃ , 5%～15% EuCl ₃ , 10% ～30%Gd(NO ₃ ) ₃ )/kg compound rare earth additive, the modified Nylen Velen chemical fiber material bio-rope manufactured is packed in the anaerobic filter reactor (AF) for the treatment of sugar wastewater, and at the same time Add inoculated sludge to start film formation at medium temperature (33-35°C), and the time to reach COD influent load 5.5kg/m ³ ·d is 35 days. Compared with the carrier without rare earth, the start-up is reduced by 12 days. The removal rate of COD is increased by 10% to 15%.

Example 4

Add chlorinated rare earth compounds to produce modified fillers, the amount of which is 6mg/kg (filler base) of CeCl ₃ , and put the manufactured modified plastic fillers into an anaerobic biological fluidized bed reactor for the treatment of sugar wastewater At the same time, add inoculation sludge to start film formation at medium temperature (33-35°C), the time to reach COD influent load 5.5kg/m ³ ·d is 39 days, compared with the carrier without rare earth, the start-up is reduced by 8 days, and the start-up After completion, the COD removal rate is increased by 8% to 15%.

Example 5

Add composite rare earth compounds to produce modified fillers, the amount of which is 3.5 mg/kg (filler base) Ce(NO ₃ ) ₃ /LaCl ₃ , and the manufactured modified plastic fillers are loaded into an aerobic biobarrier for treatment For urban sewage, add inoculated sludge at the same time to start film formation at medium temperature (33-35°C), and the time to reach the COD influent load of 0.8kg/m ³ ·d is 13 days, which is 5 days less than that without rare earth carrier. , After the startup is completed, the removal rate of COD is increased by 8% to 15%, the removal rate of TN is increased by 5% to 12%, and the removal rate of TP is increased by 5% to 15%.

Claims (5)

1. A method for improving the efficiency of attached growth wastewater treatment biofilm reactor, comprising the following steps: (A) Adding 1 to 10 mg/kg of soluble rare earth compound as an additive to the filler or filter carrier during the manufacture of the filler or filter carrier to form a modified filler or modified filter carrier; (B) Filling the above modified filler or modified filter carrier into a biofilm reactor for wastewater treatment. 2. A method for improving the efficiency of attached growth wastewater treatment biofilm reactor according to claim 1, characterized in that the rare earth compound in step (A) is a single rare earth compound or a composite rare earth compound. 3. A method for improving the efficiency of attached growth wastewater treatment biofilm reactor according to claim 2, characterized in that the soluble rare earth compound in step (A) is a nitrate or chloride rare earth compound. 4. a kind of method for improving attached growth wastewater treatment biofilm reactor efficiency according to claim 3 is characterized in that in step (A) filler and filter material carrier material can be polyethylene, polyvinyl chloride, polystyrene , polypropylene plastic or nylon, vinylon, acrylic, polyester. 5. according to a kind of method described in any one in claim 1～4 improving attached growth wastewater treatment biofilm reactor efficiency, it is characterized in that the biofilm reactor in the step (B) is biological fluidized bed, biological Turntable, biofilter, biological moving bed or biobarrier.