Effective urine removal relies on proper chemistry and efficient extraction processes. It also requires proper judgment upfront -- sometimes the best removal method is to dispose of the carpet and/or cushion. Professional urine treatments need to deal with odor, stains, breakdown of contaminants along with removal.
The first hour needs to focus on the breakdown of matter through several enzymes like protease, amylase, cellulase, and lipase. The smaller particle size allows the select bacteria strains to produce specific enzymes to break down the particulates for easier extraction and eventual cell digestion.
The extraction processes need to remove as much water as possible as the remaining liquid will contain contaminants. Along with the remaining particulates usually in the pad level, there needs to be residual bacteria to finish off the breakdown resulting in the ultimate digestion of all of the contaminants one molecule at a time.
Efficient extraction processes are at a high level when appropriate extractors are combined with Water Claw type tools where additional water can be added and removed creating state of the art flushing of contaminants. Mild acidic rinses will neutralize alkaline salts enough for ammonia odors to be neutralized while also keeping the pH in the 6 to 8 range for optimum activations. This removal can range between 80 to 90% with the right combination. The residual contaminants left in the pad are dealt with by the residual bacteria blend, which multiplies enough to digest the remaining material.
Market forces along with chemical development have aligned to make an effective one-part solution possible. The one-part solution needs to have 3 parts: effective odor removal, contaminant particle size reduction, and mechanisms to result in the stain not being visible.
Ten years ago, nylon carpet sold twice as much as polyester (including olefin and triexta) carpet. Today, polyester carpets sell 3 times as much as nylon. Urine does not stain polyester fibers but can be visible on the surface before cleaning. This visibility on the surface is easily rinsed away. The higher cost of nylon will also result in less nylon carpet being exposed to rooms in the house abused by pets.
Odor removal requires an odor encapsulate, which neutralizes the volatile organic compound malodors on contact. Fragrances can temporarily cover the malodor while other processes finish the job. Careful selection of the fragrance is essential so that the cleaner does not replace the unpleasant urine odor with a strong fragrance that may also be obnoxious.
The standard stain removal ingredient is hydrogen peroxide. Chemically it alters the stain making it invisible. Hydrogen peroxide, however, is not compatible with bacteria or enzymes, which are the best ingredients for contaminant removal. Recent developments in surfactant and enzyme technology, along with the growing popularity of polyester carpet, have lessened the need for hydrogen peroxide.
The right combination of protease, amylase, cellulase, and lipase enzymes can help break off the staining material from the fibers. The proper selection of surfactants can also assist the movement of urine pigments and can disperse them for easier removal as well as less visibility.
Misting hydrogen peroxide on any remaining stains (surface of the fibers) will limit any penetration to the pad level where the bacteria still has other work to do. It does not hurt that probably 2 out of 3 jobs will have no staining issues due to the presence of polyester carpets.
Contaminant removal results in a complete treatment. The surfactants and enzymes not only breakdown the urine pigments but also lipids and other contaminants. Decreasing particulate size makes the job of bacteria easier as it will speed up the growth of the bacteria cells. Added rinse agents attach with the smaller particulates allowing the extraction process to be more thorough.
Even at an 80% to 90% removal of bacteria and contaminants, there are enough bacteria present to multiply readily to breakdown and digest the remaining contaminants. In the worst situations with the use of copious amounts of hot water, it is wise to inject more solution into the pad level or base of the carpet in case of degradation of solution. Some residual bacteria spores will go dormant and be available for future activity if and when the pet returns to its favorite spots.
Another feature that has been added are polymers designed to stop wicking and neutralize any re-soiling residues. The copious amount of water used even with great extraction can lead to wicking. Residuals in the pad can wick to the surface during drying but can be slowed by the presence of polymers restricting the natural capillary action.
The use of surfactants and fragrances can leave enough residues to promote re-soiling. The addition of these polymers neutralizes these tendencies, so treated areas will not become more visible over time.
In short, chemical and extraction technology has developed to the point where most urine treatments can be approached with one chemical solution and one efficient flushing extraction system. Other solutions will need to be employed in serious neglect generally resulting in pad removal and sealing of sub-surfaces and in the most extreme situations, carpet disposal and replacement.