Liquid purification or separation – Processes – Making an insoluble substance or accreting suspended...
Reexamination Certificate
1994-12-27
2001-08-28
Hruskoci, Peter A. (Department: 1724)
Liquid purification or separation
Processes
Making an insoluble substance or accreting suspended...
C210S733000, C210S734000, C210S735000, C210S905000
Reexamination Certificate
active
06280631
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to the treatment of food processing wastewater. More particularly, the present invention provides a chemical treatment method that effectively removes fat, blood, tissue and other solids from food processing wastewater.
2. Description of the Prior Art
Everyday the food processing industry produces many tons of food processing waste. Such food processing waste contaminates the water stream flowing through the food processing system. For example, poultry farm waste water effluents are enriched with fat, oil, blood and other solids from the poultry process. These by-products, such as fat, blood, and tissue, are typically present in the waste water in a range of several hundred to tens of thousands of ppm.
For economic as well as regulatory reasons, the food processing community faces never-ending concerns regarding the disposal and recycling of food processing waste water. The removal of such by-products is critical from an environmental standpoint. In fact, the United States Environmental Protection Agency has placed tight restrictions on total oil and solids content in water that is be discharged into public drinking water supplies or into open bodies of water.
The removal of such solids is also critical to the established discharge limits for total dissolved solids (TDS), chemical oxygen demand (COD), biological oxygen demand (BOD) and total organic carbon (TOC) into local sewers and rivers. In addition to the EPA's severe discharge limits, food processing industries must also be concerned with local city ordinances.
As an alternative to discharging treated water into a water stream or the like, recycling of the water back into the processing system provides a cost efficient system. However, in order to recycle such waste water, the solids content and so forth must be effectively removed in order to provide pure water back into the system. Accordingly, the same concerns that are present with respect to the removal of such solids for EPA standards exist for recycling purposes as well.
Therefore, a need exists for a treatment system that addresses all the environmental concerns presented by food processing waste, while at the same time being environmentally friendly.
SUMMARY OF THE INVENTION
The present invention provides a method for conditioning food processing waste prior to mechanical dewatering with the use of environmentally friendly coagulants and flocculants. The method of the present invention comprises treating these waste waters with an effective amount of a vinylamine polymer including from about 1 to about 100 mole percent vinylamine and from about 1 to about 99 mole percent of at least one monomer selected from the group consisting of vinylformamide, vinyl alcohol, vinyl acetate, vinyl pyrrolidinone and the esters, amides, nitrites and salts of acrylic acid and methacrylic acid.
In an embodiment, the method of the present invention includes the further step of adding an effective amount of at least one flocculant to the food processing waste. The flocculant effectively agglomerates a portion of the colloidal organic solids into suspended solids.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides, for conditioning food processing waste, a method that includes the addition of a vinylamine polymer coagulant to the food processing waste. The invention provides a superior method for removing fat, blood, tissue, and the like from food processing waste. The vinylamine polymers of the present invention have been discovered to be more effective in removing such products from food processing waste and appear to be less than currently available chemical treatments. The invention comprises treating these waste waters with an effective amount of a water soluble polymer containing from about 1 to about 99 mole percent vinylamine monomer and/or a monomer hydrolyzable to vinylamine, and/or from 1-99 mole percent of amidine, vinylformamide, vinyl alcohol, vinyl acetate, vinyl pyrrolidinone or the esters, amides, nitrile and salts of acrylic acid and methacrylic acid monomer.
For purposes of this invention, vinylamine monomers include vinylamine and those monomers which are hydrolyzable to the following formula:
wherein: R and R′ are, preferably, one substituent group selected from the group consisting of hydrogen and an alkyl group having from 1-10 carbon atoms. More preferably, R is hydrogen or is an alkyl group having 1-4 carbons.
The vinylformamide monomer of the invention is non-hydrolyzed and has the following structure:
wherein: R and R′ are, preferably, one substituent group selected from the group consisting of hydrogen and an alkyl group having from 1-10 carbon atoms. More preferably, R is hydrogen or is an alkyl group having 1-4 carbons.
The amidine moiety, derived from the amine hydrolysis of polyvinyl formamide has the following structure:
According to one embodiment of the invention, the polymers of the invention include a vinylamine/vinyl alcohol copolymer. Preferably, the copolymer will include from about 1 to about 99 mole % vinylamine and about 1 to about 99% vinyl alcohol. More preferably, the copolymer will include from about 2 to about 50 mole % vinyl alcohol and from about 98 to about 50 mole % vinylamine. Most preferably, the vinyl alcohol is included in the copolymer in an amount of from about 10 to about 20 mole % and the vinylamine is included in an amount of from about 90 to about 80 mole %.
According to a further embodiment of the invention, the polymer composition includes vinylamine/vinylformamide copolymer. Preferably, the copolymer includes from about 1 to about 99% vinylamine and from about 1 to about 99% vinylformamide. More preferably, the copolymer includes from about 2 to about 50% vinylamine and from about 98 to about 50% vinylformamide. Most preferably the coagulants include 60-80% vinylamine and 40-20% vinylformamide.
According to a further embodiment of the invention, the polymer composition includes a vinylamine/vinylformamide/amidine terpolymer (A/B/C) in monomer ranges of: A 15-90%; B 5-60%; and C 5-60%. Most preferably the monomer range is about 65/5/30, respectfully.
Processes for making the polymers of the invention are well known in the art. U.S. Pat. Nos. 5,126,395, 5,037,927, 4,952,656, 4,921,621, 4,880,497 and 4,441,602 all describe methods for preparing the polymers of the invention. Solution polymerization produces the desired molecular weight dosage. The resulting vinylformamide homopolymers are susceptible to alkaline or acid hydrolysis which converts some or all of the amide groups to amine groups. These U.S. patents all describe methods for preparing the polymers of the invention. Hydrolysis of the amide groups to yield the amine can be achieved by using acid or base. By controlling the stoichiometry of the hydrolyzing agent it is possible to produce vinylamine/ vinylformamide copolymers of varying composition. If vinylformamide is polymerized with other ethylenically unsaturated monomers, then hydrolyzed, it is conceivable that the polymer produced will contain at least three and possibly more functional groups. Cyclic amidine is produced by ammonia or amine hydrolysis of polyvinylformamide.
Preferably, the vinylamine polymers of the invention have an average molecular weight of from about 10,000 to 3,000,000. More preferably, the molecular weight is from about 250K to about 2 million. Vinylamine polymers having molecular weights from about 500K to 2 million are the most preferred in treatments performed in accordance with this invention.
Generally, the dosage, based on active polymer, will be from about 0.001 to about 1,000 ppm by weight of the waste water treated. More preferably, the dosage range is between 0.01 to about 100 ppm; and most preferably, from about 1 to about 50 ppm.
In an embodiment, the method of the present invention includes the further step of adding an effective amount of a flocculant to the food processing waste. The flocculant component of the present inventio
Chung Daniel K.
Sommese Anthony G.
Breininger Thomas M.
Hruskoci Peter A.
Martin Michael B.
Nalco Chemical Company
LandOfFree
Use of polymers containing vinylamine/vinylformamide for the... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Use of polymers containing vinylamine/vinylformamide for the..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Use of polymers containing vinylamine/vinylformamide for the... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2465955