To concept of seeding an organic system with microorganisms having specific characteristics is well established for areas of industrial fermentation. These areas include industrial processes for the manufacture of antibiotics, cheeses (both aged and cottage type), yoghurt, wines, beers, baking, even pesticides. Bioaugmentation may be defined as being the process of inoculating specific microflora into a given environment so as to enhance certain biochemical processes or to elicit desirable changes in that environment. In the case of bioaugmentation of wastewater, it usually takes place in the form of a specific microbial product addition at level ranging from 0.1 to 3.0 per million (mg/l) based on influent volume. Product may be added continually or periodically (daily, weekly) depending upon the treatment unit’s design, the waste treated, and hydraulic retention time in the system.

            Bioaugmentation can be used to help minimize the problems which occur in certain waste treatment situation as outlined above. Research has shown that even in a biological waste treatment system with great numbers of indigenous microorganisms being introduces into and surviving within the system, that the continual addition of seeding microorganisms can have an appreciable effect upon the type and numbers of the microflora in the system. The microflora within a given treatment system is constantly undergoing changes in both numbers and types of microorganism represented in the pollution. These changes are effected by environmental effects such as temperature; sources of carbonaceous or nitrogenous waste type and concentration; heavy metal concentration and other toxic substances; dissolved oxygen levels; and many other influences. These changes may not  result in the selection of a pollution of microorganism that are the most effective in degrading the type of wastes that are introduced into the treatment system only on a intermittent basis. In this regards, bio augmentation may help in supplying organisms effective in their catabolic character and capabilities, thus, resulting overall treatment for a great variety of wastes.

           Just as a biological waste treatment units are designed for each individual situation and application, it would be possible to design a bioaugmentation product for most situations that present themselves. Such a bioaugmentation product would provide a continuous supply of microorganisms that are selected, mutated, and/or acclimated to the individual waste situation which has been targeted. For the biologically active seed product its effectiveness, such a product would have to be added periodically on a preventive maintenance basis. This approach would help to ensure that there was in the individual treatment system a constant population of microbes that were known to attack the specific problem compounds that existed in a given wastewater discharge.

            In the realm of sanitary engineering there is a concept known as the “Ubiquity Principle”. This concept fostered by some engineers very briefly says that for every natural organic compound in nature there are also in nature microorganism that can break down, oxidize, or in some way digest that compound. This may be true from an academic standpoint; however from a particle standpoint, it may be impossible to wait for a specific microorganism to be selected by natural means within a waste treatment unit. It may take from months to years for a treatment unit to “mature” in such a way as to be able to effectively treat some specifically troublesome wastes. After this “aging” or selection process takes place, and the system has selected specific microflora which can degrade a specific waste, it is entirely possible (and in some cases, probable) that some mechanical failure, some hydraulic accident, or some toxic shock might destroy these precious, selected microflora. The operators are then faced with insufficient, ineffective, odorous, or inefficient treatment while they await the natural selection process to begin anew. This is not only inconvenient, but is often impractical. Bioaugmentation can shorten this selection period for specific microflora and can make a treatment unit more resistant to shock loading and washout.

           In general, for each waste for which a unit is to be designed it is imperative that several logical designed steps be taken as far as the application of bioaugmentation is concerned.

   First, a comprehensive survey should be made of composition of the waste by a reputable wastewater analysis laboratory. 

   Second, possible trouble components of the wastewater must be identified.

   Third, the overall flow pattern complete with relative concentration for these pollutants should be elucidated.

   Fourth, a treatability study has to be performed on composite samples of the waste utilizing suitable respirometry techniques. 

          Finally, a suitable bioaugmentation product should be compounded for use according to the particular waste pattern from the existing repertoire of biological components available and tested on the wastewater.

          Following is an outline of the specific trouble areas for which seed cultures are either available or where more research needs to be carried out in order to develop bioaugmentation products which are suitable for use in packaged waste treatment units:

           In the previously mentioned area of ammonia oxidation and nitrogen removal in treatment units where nitrogen containing wastes make up the greatest portion of the influent waste, some cultures have been identified which could potentially have use. However, each treatment unit in this regard may be unique. Operating conditions and wastes that present excessive nitrogen problems are all very different. Therefore, each case must be treated on an individual basis. Acclimation, bench testing, and selection may be required for each individual case. Where high nitrogen waste is being treated, it is necessary for the unit’s design to be engineered for optimal removal and oxidation of the nitrogen by conventional techniques. Further research needs to be done for selection and mutational work to identify and produce bacteria that are truly effective and have suitable shelf life for particle application in the field. In a related process step, organisms that can denitrify nitrate and thus remove nitrogen from a system are presently.

           For typical sanitary sewage as are now being treated in municipal treatment plants a variety of Baxel's formulation are presently available for routine and preventive treatment. The “aging” or start up period of these units can be shortened with technology now available. Likewise, in the case of situations where vegetable and animal fats and greases cause problems, effective Bac-ZymeTM products are available. It is possible that additional work in acclimation and mutation may be effective in producing bacteria with much better activity on greases with less expense to the consumer.

           Bioaugmentation products like Bac-ZymeTM are formulated which help units to work more efficiently and help the microflora remain more active. In some cases the microflora may be selected so as to produce their own flocculating agents thus eliminating the need for polyelectrolyte addition to the system.

           Many hydrocarbonaceous wastes can now be effectively treated using the Bac-ZymeTM bioaugmentation agents. However, it is necessary that each industrial waste containing aromatic hydrocarbons, or aliphatic hydrocarbons, or disinfectant, herbicides, etc. be subjected to particularly comprehensive treatability studies so as to assure effectiveness and reliability of the specific Bac-ZymeTM products. Some synthetic chemical compounds can not effectively be treated by biological means at this time.

            In summary, there are many apparent ways in which bioaugmentation with seeding microbial cultures may assist in making packaged or conventional waste treatment units more reliable and efficient in operation. From a microbial standpoint, packaged and/or turnkey biological waste treatment systems, particularly for those mobile application areas offer some unique considerations in design and product use. The wastes treated as well as the type of treatment techniques in the above cases may be unique. In many cases Bac-ZymeTM products are available for use to augment to microflora in such systems; however, in many cases, intensive research needs to be continued. For specific applications, microbial product engineering should be closely coordinated with process design and equipment engineering. 

Potential Problems in Packaged Biological Waste Treatment Systems. 

Packaged system for the purpose of discussion here should be considered as any waste treatment unit which is in the most part prefabricated or in which many components are factory-built or prefabricated and which can be set up site with more labor being devoted to assembly of components than actual construction on site. Furthermore, these types of units typically have standardization of components which are used in several types and sizes of application; these aforementioned components are also used in multiples for larger unit installations. Their construction is often of lightweight synthetic material such as fiberglass reinforced epoxy, other polymeric materials, or steel and alloys rather than the concrete much smaller amounts of waste, more unique influent character, and/or in more isolated locations than do larger conventional treatment plants. Packaged plants which are in stationary, on-land locations are usually constructed, assembled, and installed above ground level.

            While most problems encountered in the case of packaged treatment units are not unique in the wastewater treatment field, there are several problems that become acute in the field of these packaged systems. These problems occur because of the limitation in type of pollutant waste that being treated. The polluting components of the waste treated in packaged units are often present in much higher concentrations than in typical large municipal waste treatment systems and often there is a nutritional imbalance as far as microflora are concerned the character of the waste is more limited in nature. For example, individual components in a waste derived from a small collection area may reach very high levels which cause problems, while in typical regional municipal systems these troublesome components are diluted and further blended with other types of pollutants. 

            Excessive accumulation of ammonia nitrogen can be an aesthetic problem as well as a functional problem. The ammonia odor is displeasing particularly in a workplace or residential area. The pH of an operating system climbs into a highly alkaline range when ammonia level rise, resulting in reduced activity by certain bacteria and reduced efficiency of operation and removal of biochemical oxygen demand (BOD) from the wastewater. 

            Several types of packaged and/or turnkey system have been used with varying success in treatment of wastes other than sanitary sewage. Herbicide and pesticide residues, machine oils, petrochemicals, disinfectants, precursors for manufacturing processes, dyes, and chemical feedstocks all contribute to possible problems sure to be encountered in treatment of industrial wastes. The problems of toxic shock and proper acclimation of microorganisms in the system become apparent when certain industrial wastes are treated. These wastewater influents often contain unusually high concentrations of synthetic, organic, and/or hydrocarbonaceous wastes.

            Institutional, restaurant and hotel wastewater can contain a high concentration of animal and vegetable fats and greases. This grease can accumulate in tanks and lines causing hydraulic problems. Resultant resistance and decrease in flow can cause mechanical failure, displeasing odors, and excessive power use.

            Settleability often becomes a problem in biological waste treatment units and the remedy for this problem in the past has often been the addition of polyelectrolytes which cause various particles to attract because of electrostatic charge, to form larger particles and in turn, to settle more easily within the system. The disadvantage of using such agent is that they add to treatment costs appreciably and that they can on occasion increase sludge volume.

            Often area that may present special problems are : waste that foam, high cellulose waste, pH ranges outside of the neutral range, waste with high and undesirable color and operating waters with high or varying sodium chloride and other salt concentrations.

            Packaged units often experience startup problems which require an “aging” of the microflora in order to acclimate and select the optimal bacteria for the digestion of that particular type of organic waste. This condition lengthens the time it takes before a system is effectively on line with efficient treatment.

Special Programs Encountered with Industrial Wastewater.

            Industrial wastewater often have unique characteristics which yield unique problems to the waste treatment engineer. Wastes that are in themselves toxic, or contain toxic levels of heavy metals, acids, bases, oxidants, etc. are the rule rather than exception. Charges in the intensity of color or odors of industrial wastes may be required. This is often very difficult to effect. 

            Even wasted that are not in themselves toxic often contain imbalances in the carbon : nitrogen : phosphorus ratio that prevent them from being effective treated. Correcting wastes to the proper ratio of pH or nutrient is often most expensive. Nevertheless, bioaugmentation may be a logical approach to the effective treatment of industrial wastewater or to the bioremediation of spills of industrial wastes. Given a sufficient length of hydraulic retention time and proper conditions for bio-oxidation of the waste, bioaugmentation can be used as another tool to add to the efficiency, and reliability of industrial wastewater treatment.