CN115215447A - A method of wastewater treatment by bioaugmentation process - Google Patents

Abstract

The present invention provides a method for wastewater treatment by a bio-augmentation process that combines several water treatment processes to biologically treat wastewater. The first treatment process is bioaugmentation, which uses a mixture of selected microorganisms grown from waste collected from wastewater treatment plants to treat wastewater flowing through its delivery system. The second process is to use a flow control device that increases the holding capacity of the delivery system to increase the time of biological treatment and allow the contained water to be discharged at a controlled rate of decline and level. The third treatment process is a high speed clarification system, preferably using flocculating polymers to remove fine suspended solids from wastewater.

Description

A method of wastewater treatment by bioaugmentation process

technical field

The present invention relates to a process for the treatment of solid waste from a wastewater treatment plant that receives domestic waste from human activities to grow for enhanced wastewater treatment plant operation and biological treatment.

Background technique

There are many problems associated with wet weather events such as hurricanes. A major issue is the treatment of sewage, which can occur in the form of combined sewer overflows, separate sewer overflows, and stormwater. The treatment of overflow problems and other water contamination associated with wet weather events is primarily a biological treatment process that requires certain conditions to be met to perform effectively.

Before the 20th century, open sewers, consisting of gutters and urban riverbeds, were common around the world. Huge efforts were made in most developed countries in the late 19th and early 20th centuries to cover formerly open sewers, converting them to closed systems. However, since most cities did not have sewage treatment plants at the time, the cost of two separate sewer systems was high, so no separate domestic sewage system was built. So stormwater and domestic sewage are combined into one system called a combined sewer system. Combined sewer systems are typically 10 to 100 times the size of the average dry weather sewage flow. As sewage treatment plants began to be constructed, it was not feasible to treat so much water, so the plants usually only dealt with the amount of sewage flowing in dry weather. A diverter structure was installed in the collection system to bypass untreated sewage mixed with surface runoff during wet weather events, protecting the sewage treatment plant from overflows, but this practice resulted in untreated sewage in heavy rainfall Released with rainwater during the event.

Such overflows from combined sewer systems are known as combined sewer overflows and can cause serious water pollution problems when discharged untreated during wet weather events. These emissions contain human and industrial waste and can lead to reduced recreational use and contamination of drinking water sources.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a novel and efficient biological treatment method for wastewater.

Furthermore, one object of the present invention is the use of bioaugmentation (the use of microorganisms to help biologically treat pollution) in wastewater treatment, including bacteria and bacteriophages (viruses).

Furthermore, it is an object of the present invention to bioaugmentation comprising a mixture of ideally selected microorganisms to biologically treat wastewater, preferably a membrane-forming facultative Bacillus.

Furthermore, it is an object of the present invention to use bioaugmentation to treat wastewater in its delivery system, which may include pipelines, canals and riverbeds, in order to provide sufficient residence time for effective biological treatment.

Furthermore, it is an object of the present invention to carry out bioaugmentation in a delivery system as close as possible to, but preferably at, the source of contamination.

Furthermore, it is an object of the present invention to grow a mixture of selected microorganisms in close proximity to a source of organic material (as food for the microorganisms) and a source of contamination.

Furthermore, it is an object of the present invention to utilize the biosolids produced by the sewage treatment plant to grow selected microorganisms for use within the sewage treatment plant and to transport the microorganisms to the wastewater conveying system through pipes contained within the conveying system.

Furthermore, the purpose of the present invention is to sterilize the biosolids of sewage treatment plants and convert them into a food source to grow selected beneficial microorganisms for biological treatment of wastewater.

Furthermore, it is an object of the present invention to add one or more flow control devices to increase the holding capacity of the wastewater delivery system, which will provide more time for the mixture of selected microorganisms to perform their water treatment functions.

Furthermore, it is an object of the present invention to use high speed clarification and flocculation polymers, preferably in a system using magnetite as ballast material in a high speed clarification system, to remove fine suspended solids contained in wastewater so that treated wastewater can be Can be discharged directly into the environment.

The importance of flow control in the system stems from the fact that the flow during wet weather can be 10 to 100 times the flow in the water delivery system during dry weather. Without the use of variable height weirs to delay part of the storm flow, the storm flow would be too large to allow sufficient time for microorganisms to biologically treat the wastewater. Another important function of a flow control device is to level the wastewater over a period of time so that it can be clarified and disinfected at a slower rate over a longer period of time. It is also within the scope of the present invention to extend wastewater conveyance systems (eg canals) along the edge of the riverbed in order to increase residence time for biological treatment and save space. In some cases the wastewater delivery system can actually be placed in the river bed.

The third aspect of the treatment according to the invention is efficient clarification followed by disinfection if necessary. In order to reach the total suspended solids limit, clarification is necessary because the limit level affects basic oxygen demand, which is a measure of organic content and bacterial levels, so fine suspended solids must be removed. The most effective way to remove fines is to use flocculation polymers for high-speed clarification. Due to the high flow rate during heavy rain, only high flow rate clarification is applicable, mainly because of space and cost constraints. The present invention contemplates a high speed clarification process using clarifiers with surface spill rates greater than 10 gallons per minute.

High-speed clarification produces a concentrated slurry of suspended solids of approximately 1-5% by weight of suspended solids. This slurry can be dewatered mechanically to produce a dry filter cake that can be used either in landfill or onshore. Another economical solution is to flow the concentrated slurry into a dewatering vessel that will allow sufficient time for the solids to settle and then periodically remove as more concentrated wet solids. This wet solid can be used on land but cannot be landfilled unless it passes the paint filter drip test. Assuming the total suspended solids content is low enough to meet regulatory limits, the dehydrated containment supernatant can be drained directly. The best solution, however, is to apply the concentrated slurry from a high-speed clarification system or dewatering vessel directly to the land to improve soil conditions, or to a wastewater treatment plant to increase biological treatment capacity.

The effectiveness of a biological treatment system depends on the type of microorganisms and the conditions that promote the growth of healthy populations of microorganisms. The two basic types of microorganisms are mobile organisms, which are free-floating and immobile microorganisms that attach to some solid surface. The effectiveness of biological treatment systems is enhanced when both mobile and stationary microorganisms are present. Increasing the surface area for immobilized microorganisms to attach to can increase the concentration of microorganisms, thereby increasing the effectiveness of the biological treatment process.

Description of drawings

Figure 1 shows an overview of the treatment technologies employed in accordance with the present invention and how they can be integrated to produce the desired results for economical treatment of wastewater.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

As shown in Figure 1, wastewater (1) flowing through a water delivery system (2), such as lakes, rivers, water storage structures, etc., is injected with a mixture of selected microorganisms (37) that Treating waste water in the water delivery system (2) to consume unwanted organic matter. Organisms may include facultative bacilli and bacteriophages. The water delivery system (2) containing the flowing stream of wastewater (1) contains a large number of biological carriers (14) which adhere to the inner surface of the water delivery system (2) to increase the surface area for biofilm growth. Also injected at or near the beginning of the delivery system (2) is a mixture of selected microorganisms (37) grown in a growth system (38), as shown in Figure 1, using the Organic waste (30) and other organic waste (31).

Claims (9)

1. A method of wastewater treatment by a bioaugmentation process, characterized by: growing selected microorganisms at a wastewater treatment plant using appropriately treated solid and liquid waste and other waste produced or received; introducing a mixture of selected microorganisms into an inlet end of a wastewater delivery system to convert the delivery system into a treatment system capable of on-line destruction of harmful microorganisms, treatment of toxic organics, BOD reduction and nutrient removal from a wastewater stream; adjustable flow control devices are provided in the wastewater delivery system to allow control of wastewater accumulation within the delivery system, thereby controlling the residence time of wastewater streams in the delivery system and providing high speed clarification treatment to treat wastewater biologically treated in the delivery system to meet discharge limits and end use requirements.

2. A method of wastewater treatment by a bioaugmentation process as claimed in claim 1, wherein the mixture of selected microorganisms contains free-floating and film-forming bacteria and bacteriophages that have adverse effects on harmful bacteria (such as SBR bacteria and other microorganisms).

3. A method of wastewater treatment by a bioaugmentation process as in claim 1, wherein the mixture of selected microorganisms comprises bacillus thuringiensis and bacillus sphaericus for mosquito killing.

4. A method of wastewater treatment by a bioaugmentation process as in claim 1, wherein the mixture of selected microorganisms is grown at or near the site where the nutrients found in the contaminants or other organic waste enter the delivery system as a food source.

5. A method of wastewater treatment by a bioaugmentation process as in claim 1, wherein the mixture of selected microorganisms is grown at or near the site where the nutrients found in the contaminants or other organic waste enter the delivery system as a food source.

6. A method of wastewater treatment by a bioaugmentation process as in claim 1, wherein attached bio-carrier surfaces are added to a transport system comprising pipes, canals, rivers and riverbeds to promote the growth of selected microorganisms as biofilms.

7. A method of wastewater treatment by a bioaugmentation process as in claim 6, wherein the transport system may be a pipe, canal or natural waterway, extended by an artificial canal or other transport system added alongside or within a river or stream to increase residence time so that biological treatment may continue to treat the wastewater prior to entering the river or stream.

8. A method of wastewater treatment by a bio-augmentation process as claimed in claim 1, wherein biosolids or other waste received from sewage treatment plants are disinfected and lysed to produce suitable food products to grow the selected microorganisms.

9. A method of wastewater treatment by a bioaugmentation process as in claim 1, wherein the waste used to culture the selected microorganisms is disinfected and lysed by methods including but not limited to mechanical, thermal, electrical, sonic methods, but preferably hydrodynamic cavitation to kill unwanted competing microorganisms, including pathogenic bacteria and Sulfur Reducing Bacteria (SRB), and to increase the food value of the waste by releasing a cellular protoplasm content that favors the culture of the selected microorganisms.

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