WO1999051531A1

WO1999051531A1 - Waste treatment system and method

Info

Publication number: WO1999051531A1
Application number: PCT/US1999/007528
Authority: WO
Inventors: T. Ronald Theodore
Original assignee: Theodore T Ronald
Priority date: 1998-04-07
Filing date: 1999-04-06
Publication date: 1999-10-14
Also published as: WO1999051531A8; AU3384399A

Abstract

A waste treatment system (10), method, and test, are disclosed which employ the use of zwitterionic compounds (22) like HEPES, to increase oxygen efficiency and to increase the rate of biological oxygen demand (BOD) of the treated waste, either in a waste treatment system (10) or a test of waste samples for BOD.

Description

WASTE TREATMENT SYSTEM AND METHOD Reference to Prior Application

This application claims the benefit of and filing date of U.S. Provisional Patent Application Serial No. 60/080,947, filed April 7, 1998.

Background of the Invention Zwitterionic molecules are compounds that have both positive and negative charges. It is known that these zwitterionic molecules are true biological response modifiers, see U.S. Patent No. 5,716,959, issued February 10, 1998, which was filed as PCT Application No. US97/02270 on February 13, 1997, hereby incorporated by reference.

Further, it is known that zwitterionic molecules enter the mitochondria of cells and increase the rate of oxidative phosphorylation. Other mechanisms involved are the stimulation of various physiological pathways, the effect on specific cell systems, changes in cell membrane- potentials, and changes in ion exchange and diffusion in cellular membranes. It has been shown that microbial sensitivity to antibiotics is effected by the zwitterionic molecules.

Bιymm«ι-γ nf the Invention

The invention comprises improved waste or sewage treatment systems and processes in waste or sewage treatment plants with the use of zwitterionic compounds to improve oxygen use or biological oxygen demand (BOD) streams. The addition of zwitterionic molecules to microbes found in waste increases BOD and the efficiency by which oxygen is utilized in a waste treatment system and process. The outcome is a reduction in the energy requirements needed for aeration as part of the waste treatment system and process.

The invention employs a waste treatment system which comprises: a primary sedimentation tank for a waste input stream; an aeration basin with oxygen utilizing microbes to degrade organic matter and to receive a nonsedimentary waste stream for aeration from the primary sedimentation tank; a means to introduce air into the aeration basin to aerate the waste stream; a means to introduce a zwitterionic compound prior to or into the aeration basin in an amount sufficient to increase aeration efficiency or B.O.D. in the aeration basin; a secondary sedimentation tank to receive an aerated waste stream from the aeration basis and to provide secondary sedimentation; a disinfection tank to treat the secondary aerated waste stream with a disinfectant agent; and a means to withdraw a treated outfall stream. The invention also employs a method of treatment of a waste influent which comprises adding to the waste influent or sample an amount of a zwitterionic compound to increase the rate and oxidation efficiency and BOD of the waste influent and/or sample. It has been discovered that the method of the invention increases BOD in a waste test sample, which method comprises adding an amount of a zwitterionic compound to a waste test sample in a container to increase the BOD of the waste test sample, incubating the container, and determining the BOD of the waste test sample in the container after incubation.

In summary, it has been found that zwitterionic compounds increase BOD in microbial and cell systems, reduce the time to determine BOD in open and/or closed microbial and/or cell systems, reduce the culture time in microbial and/or cell systems and improve oxygen utilization in microbial and/or cell systems and waste treatment processes. Zwitterionic compounds also shorten the culture time to determine BOD in monitoring systems. Further, the use of zwitterionic compounds in waste treatment processes reduces the amount of energy required for aeration and/or other processes, improves the amount and rate of degradation of waste products, increases the BOD of influent, and reduces the BOD of the outfall.

In the processing of waste products, typically, influent is passed through screens, is followed by grit removal, and then passes into primary sedimentation tanks. Occasionally, a precipitating or settling agent, such as a salt, e.g., ferrous chloride, is added to the influent between grit removal and the primary sedimentation tanks to aid settling. From the primary sedimentation tanks, the influent passes into aeration basins. In the aeration basins, air is forced through the influent to provide oxygen to meet the demands of organic degradation, which is aided by the presence of microbes. The activity of degradation oxygen demand is measured by standard BOD techniques. After aeration, the influent continues into secondary sedimentation tanks. The degree of degradation correlates to the measurement of the BOD. It then passes into a treatment tank where chlorine is normally added to the influent. The chlorine-treated influent becomes the effluent sewerage discharge known as outfall.

The purpose of adding chlorine to the outfall prior to discharge is to ensure that the microbes are destroyed. There are other methods of disinfection that may or may not be employed including, but not limited to, ozonation and/or exposure to ultraviolet light.

Outfall effluent is monitored for BOD. The BOD of the outfall is theoretically met in the aeration tanks. Thus, the oxygen requirements for degradation, both by decomposition and by microbial oxygen demands would be satisfied. Theoretically, disinfection (chlorination) assumes destruction of all microbes. The purpose of meeting BOD levels prior to discharge of the effluent outfall is to insure decrease of BOD of the waste that is discharged. This decrease of BOD in the outfall lowers and/or prevents oxygen loss in the environments that would create anaerobic conditions to fish, algae, normal flora, and all other environmental factors that require oxygen.

It has been found that there are significant advantages realized when increasing the BOD in the primary aeration tanks with zwitterionic compounds. The BOD is increased by elevating the rate of oxidative phosphorylation, which directly increases the metabolic activity of the microbes in the waste system, resulting in increased oxygen consumption, while at the same time, increasing the rate of organic degradation of the influent. The outcome is a more efficient use of the available oxygen in the influent, even prior to aeration. The benefit of adding oxygen by aeration is intensified by this method. Also, since oxygen utilization and degradation are increased without aeration, the need for aeration in the system and process lessens. This allows for less aeration to be required, resulting in reduced energy requirements needed to run the aeration units. Alternatively, it provides increased degradation at the usual level of aeration, which results in more complete degradation of the effluent outfall.

The invention comprises the introduction and use of zwitterionic compounds, e.g., HEPES, MOPS, and tricine into the influent prior to or during processing in aeration tanks, particularly, of sewage systems to increase BOD in the process and result in a lower BOD in the outfall effluent. The HEPES has the highest rate of increased oxidative phosphorylation. Comparatively, MOPS and tricine are approximately thirty percent (30%) or more, less effective in increasing BOD as compared to HEPES. Further, HEPES renders the least potential for cytotoxicity. The zwitterionic compounds may be used alone; in various combinations with other zwitterionic compounds; or with, or in addition to other noninterfering agents and chemicals used in the microbial system and process. The zwitterionic compounds are used in various amounts sufficient to increase oxygen efficiency, increase BOD, or both, depending on the system demand and requirements. The zwitterionic compounds include compounds in a heterocyclic ring or straight chain, which typically contain one or more nitrogen atoms and include acidic groups like: carboxylic; sulfonic; or phosphoric and alkaline groups like: amines and hydroxyl groups.

In another embodiment of the invention, BOD is employed to monitor the efficacy of a biological-based waste or sewage waste system. Several BOD monitoring methods are employed, all of which methods employ the use of a container with a culture and require incubation of the culture after treatment with a sample of the waste stream, and the results obscured or measured with a BOD meter, and on average it takes about five days to obtain the BOD test results.

It has been discovered that the BOD culture method of testing for BOD is made more effective and rapid in time by the addition of a zwitterionic compound to the culture medium employed, since the zwitterionic compound increases the rate of oxidative phosphorylation in test culture, thus decreasing the culture test time.

The invention will be described for the purpose of illustration only in connection with a waste or sewage treatment system and method of operating the system; however, it is recognized that various changes, modifications, additions, and improvements may be made to the illustrated system and method without departing from the spirit or scope of the invention.

Brief Description of the Drawing The drawing is a schematic block diagram of a waste treatment plant and process of the invention. Description of the Fιηhoriiτngτvr:κ The drawing shows a system and process 10 with a sewage waste stream containing sediment and degradable organic matter as an influent flow source 12.

The influent flow is passed through screens 14 to remove solid particulate material and through a grit removal source

16 to remove finer grit particles. Optionally, a settling or precipitating agent 18 is added to the influent stream, and the influent is directed to one or more primary sedimentation tanks 20, for a selected time, to permit precipitated matter to settle.

The waste stream, less the settled matter, is removed from the primary sedimentation tank 20 and one or a series of aeration basins 24, where air from source 26 is pumped through the waste material to provide for the microbes to degrade organic matter.

A zwitterionic compound from a source 22, like HEPES in tablet, powder, or water solution form is introduced into the waste stream prior to or directly into one or more of the aeration basins 24 to increase the air (oxygen) efficiency and increase the BOD of the waste stream.

Waste material from the aeration basin 24 is directed to one or more secondary sedimentation tanks 28 and the output from the tanks treated with a disinfecting agent, like a chlorine solution 30, in a disinfection tank 32 and a treated outfall stream 34 is removed from the system. Rvample 1

A zwitterionic compound, 2N hydroxyethyl-piperazine ethane sulfonic acid (HEPES), is added in concentrations from about 500 mg to 100 kg per liter of influent. BOD in the outfall is measured by standard techniques and compared to normal outfall BOD in standard aeration systems. As the concentration of HEPES is increased in the aeration tank, BOD is decreased in the outfall.

Varying concentrations of HEPES {4-(2 hydroxyethyl)-l- piperazine ethane sulfonic acid} were prepared by adding the HEPES to 300 ml of distilled sterile water containing glucose and glutamic acid (GGA) and Polyseed (multiple bacteria test capsule) . The concentration of HEPES varied from 3 mg/ml to 96 mg/ml in the various samples. The samples were incubated for a period of five (5) days. BOD was measured with a YSI Model #5100 Biological Oxygen Demand Meter. BOD measurements were done on aliquots of these samples, at varying concentrations, after three, four and five days (see Table 1). Several additional samples containing HEPES at various concentrations were analyzed without the addition GGA.

The data shows that BOD values increase with increase in incubation period. BOD values also increase with increase in HEPES concentration. There is a contribution to BOD directly from the HEPES, which increases with concentration. It is also contemplated that a number of tests and test techniques may be used to measure BOD in addition to that noted.

Further, it is noted that BOD decreases with increasing concentrations of HEPES when there is an absence of nutrients or media for microbial and/or cellular growth. These nutrients and/or media are required to produce metabolic activity. Example 2 A zwitterionic compound (HEPES) is added in concentrations from 0.5 g/L to 10 kg/L to the influent. BOD in the influent rose 30 to 60 percent (30-60%) above baseline untreated influent. BOD in the outfall is measured by standard techniques and compared to acceptable levels in municipal outfall. The BOD levels in treated outfall reached acceptable levels thirty percent (30%) sooner. Further, when the process is continued to normal times, BOD is thirty percent (30%) or more, lower than usual levels. As the concentration of HEPES is increased in the aeration tank, BOD in the outfall is decreased.

Example 3

Additional Zwitterion Data Tricine and MOPS

In addition to the data on HEPES presented in Table 1 , two other zwitterions were 5 also tested. As noted in the summary, both Tricine and MOPS were tested showing an effect on biological oxygen demand. The data is summarized in Tables 2 and 3.

Table 2

Tricine: (N-tris[Hydroxymethyl] methylglycine:N-[2-Hydroxy-l, 1 bis (hydroxymethyl) ethylj-glycine)

T O Sample Incubation GGA Concentration BOD

No. Time Added Tricine (mg/ml) (mg/L)

200001 3 Days Y 3 124

200001 4 Days Y 3 154

200001 5 Days N 3 114

1 5 200003 3 Days Y 12 182

200003 5 Days Y 12 221

200003 5 Days N 12 84

200004 3 Days Y 24 220

200004 4 Days Y 24 250

20 200004 5 Days Y 24 273

Table 3

MOPS: ( 3-[N-Morpholino] propanesulfonic acid)

300001 3 Days Y 3 121

300001 4 Days Y 3 123

2 5 300001 5 Days N 3 118

300003 3 Days Y 12 148

300003 5 Days Y 12 183

300003 5 Days N 12 87

300004 3 Days Y 24 178

30 300004 4 Days Y 24 235

300004 5 Days Y 24 257

Claims

Claims What is claimed is:

Claim 1. A waste treatment system which comprises: a) a primary sedimentation tank for a waste input stream; b) an aeration basin with oxygen utilizing microbes to degrade organic matter and to receive a nonsedimentary waste stream for aeration from the primary sedimentation tank; c) a means to introduce air into the aeration basin to aerate the waste stream; d) a means to introduce a zwitterionic compound prior to or into the aeration basin in an amount sufficient to increase aeration efficiency or BOD in the aeration basin; e) a secondary sedimentation tank to receive an aerated waste stream from the aeration basis and to provide secondary sedimentation; f) a disinfection tank to treat the secondary aerated waste stream with a disinfectant agent; and g) a means to withdraw a treated outfall stream.

Claim 2. The system of claim 1 wherein the amount of zwitterionic compound ranges from about 500 mg to 10 kg per liter of waste input stream.

Claim 3. The system of claim 1 wherein the zwitterionic compounds are selected from the group consisting of: HEPES; MOPS; tricine; and combinations thereof.

Claim 4. The system of claim 1 which includes a sewage source, and the input stream comprises a sewage stream from said source.

Claim 5. A waste treatment system which comprises: a) a container with microbes, which microbes in the presence of oxygen, degrade organic material in contact with the microbes; and b) a means to add a sufficient amount of a zwitterionic compound to the container to increase the rate of oxidative phosphorylation of the microbes.

Claim 6. A system of claim 5 wherein the system comprises a test kit for BOD culture 9 media-containing nutrients .

Claim 7. A method of treatment of a waste influent which comprises adding to the waste influent or sample an amount of a zwitterionic compound to increase the rate and oxidation efficiency and BOD of the waste influent and/or sample.

Claim 8. The method of claim 7 wherein the waste stream comprises a waste sewage stream in an aeration basin.

Claim 9. The method of claim 7 which includes adding the zwitterionic compound prior to or during aeration of the waste stream.

Claim 10. The method of claim 7 wherein the amount of zwitterionic compound ranges from about 500 mg to 10 kg per liter of the waste stream.

Claim 11. The method of claim 7 wherein the zwitterionic compound is selected from the group consisting of: HEPES; MOPS;, tricine; and combinations thereof.

Claim 12. The method of claim 7 wherein the zwitterionic compound comprises a nitrogen-containing organic compound having carboxylic, phosphorous, or sulfonic acid groups and hydroxy or amine alkaline groups.

Claim 13. A method of increasing BOD in a waste test sample, which method comprises: a) adding an amount of a zwitterionic compound to a waste test sample in a container to increase the BOD of the waste test sample; b) incubating the container; and c) determining the BOD of the waste test sample in the container after incubation.