Bacteria are nature's recyclers. They have the ability to degrade an astonishing number of compounds, due to their evolution in myriad locations over millions of years, enhancing their suitability for a large variety of natural and manmade systems. Once the environmental and nutritional requirements of different species of bacteria are quantified, their abilities to completely clean and re-stabilize a system can be harnessed. Certain challenge and selection techniques can be employed to further enhance their appetites for certain difficult to degrade compounds.
Exactly how do bacteria degrade waste?
Bacteria produce enzymes that allow them to break up complex compounds into pieces that can enter the cell to be used for growth and reproduction. Some bacteria use the carbohydrates and proteins usually found in the suspended solids that elevate biochemical oxygen demand (BOD), while others employ compounds most organisms cannot, such as sulphide, ammonia and hydrocarbons. When added to water, the bacteria attach themselves to solid particles, whether floating in the water or settled on the bottom, and secrete enzymes which decompose the particles. Certain dissolved compounds, such as ammonia and sulphide, are absorbed directly into the cell. Combinations of species often provide a more powerful and complete degradation of specific pollutants than individual strains applied alone, because the by-products of one species often serve as another species' food. Only a correctly balanced formula of bacterial strains can use this synergistic effect to completely break down pollutants to non-toxic by-products such as carbon dioxide, water and sulphate.
What happens to the bacteria when the job is done?
Bacteria replicate at an enormously fast rate when they are well fed, about once every 15 to 20 minutes, depending on the species. The bacteria will replicate as long as the pollutants in the system can feed the population. As the pollution level decreases, the bacteria die off and reproduce less often. In this way, the population naturally tailors itself to the pollution level. By the time the job is done, the bacteria have died back to a normal population. Some will go into dormancy, and reactivate if the pollution level begins to rise again.
Are the bacteria or fungi genetically engineered?
No. The bacteria and fungi used are natural environmental isolates, selected for desirable properties and challenge adapted.
They are not genetically altered in any way.
Are the bacteria and fungi non-pathogenic (are not a cause of disease) to humans, animals and plants?
The microbial products are certified Salmonella and Shigella-free. Some products are also tested for E.coli and Streptococcus. The products cause no short or long-term detrimental ecological effects. In fact, by reducing total suspended solids (TSS), ammonia salts, hydrogen sulphide, and other contaminants in lakes, ponds or reservoirs.
The products are safe for use in any aquatic environment, for use around fish, crustaceans (lobsters, shrimps, prawns, etc.), animals, frogs, alligators, worms, Artemia and protozoa. The products are used to restore a natural BALANCE to the aquatic environment. A naturally balanced aquatic environment must maintain a small amount of algae and micro-algae to feed certain protozoa and the young of some larger species, and are themselves feed for larger species of fish. An unbalanced system will have huge overgrowths of algae that eventually die suddenly in what is termed an "algal crash", killing many other species when this happens. The products will also improve the immune systems of fish and crustaceans, helping them to better fend off disease, so the entire system becomes healthier. Specific formulas are designed to solve specific problems in the system.
Specific products marked with "no fish" contain surfactants which are NOT safe for use around fish, but the bacteria and fungi in those products ARE safe for use anywhere.
Are the products safe for fish?YES! The products improve the aquatic environment for fish and other wildlife by removing ammonia and sludge from the water column.
If these bacteria and fungi are already present in nature, why do they have to be added to a natural system?
The bacteria and fungi in nature are kept in check by organisms in the food chain that eat them and are not always suited to the kind of wastes in which they find themselves. In the case of a tough pollutant such as cyanide, the natural bacteria may not be accustomed to using it as a food source. By flooding the system with a carefully selected and enhanced combination of organisms, the added bacteria have an enormous competitive advantage, and are free and able to handle the wastes at a given site.
The bacteria has been adapted to prefer specific difficult-to-degrade wastes. After adapting the strains to a specific purpose, the strains are blended in a particular formula to suit the intended task. Without an artificial selection process, each succeeding generation (after the first 10) reverts more and more toward the "wild", again, preferring simpler carbon sources, such as sugars, found in the waste stream. In other words, after "breeding" in a waste stream with a low concentration of the target substance, for 10 or more generations, the descendants become more and more indistinguishable from the wild population. Of course, if the waste stream is highly concentrated with the target substance, and the waste flow is fairly constant, the maintenance dose can be cut back until it is miniscule.
Can the products control weeds?
Since aquatic weeds do not feed from the water column, instead absorbing their nutrients directly from the sludge layer, they are not as immediately affected. Bacteria can be used to break down up to 90% of the organic sludge layer over six months to a year, depending on the depth of the sludge and its proportion to the water depth, with the added benefit of eventually reducing water weeds.
What kind of pollutants does the bacteria target?
Virtually all organic contaminants except PCBs can be degraded with bacteria. These include but are not limited to: sludge, manure, grease, oil, chlorides, ammonia, nitrite, sulphide, some pesticides, hydrocarbons, cyanide and phenols.
How do bacteria products clarify the water?
The bacteria products reduce the Total Suspended Solids (TSS) that cloud the water column by digesting the floating organic matter.
How do the products deal with phosphorus in the water body?
The bacteria can absorb some phosphorus (as PO4) in their cell mass, using it as a nutrient catalyst in the production of enzymes and proteins. The bacteria also use phosphorus in cell reproduction, making it unavailable as a food source for algae and aquatic plants.
Two strains of Pseudomonas putida found in ETG products are designated as "phosphate accumulating", which means that under aerobic conditions, they will accumulate more phosphate than is needed as a nutrient for cell mass survival and growth. These same strains will release phosphate under anaerobic conditions or when they die, so "phosphate accumulating" is not a universally perfect solution to the presence of phosphate, as some competitors advise. Also some products have an Acinetobacter strain, used in certain wastewater treatment formulas, which is also a phosphate accumulator. ETG have developed
How is odour controlled?By accelerating the natural nitrogen cycle, various formulas enhance the rate at which ammonia is converted into nitrite and then into nitrate, eliminating the release of ammonia gas. Besides the known strains of nitrifiers some products have two strains of Paracoccus pantotrophus and one strain of Bacillus mojavensis that oxidize ammonia heterotrophically to nitrite.
A number of products contain special strains selected for their ability to biodegrade hydrogen sulphide, eliminating these odours as well.
Where can the products be used?The products have been used for lakes and ponds, industrial wastewater, aquaculture, landfill leachate, greenhouse irrigation water, agricultural waste, groundwater pollution and restaurant waste. Since many pollutants are ubiquitous, applications are numerous and ever expanding
How do chemical algaecides cause long-term problems?
By killing off ALL algae and most beneficial bacteria, chemical algaecides put additional nutrients (degradable dead algae) back into a water column. Small fish and protozoa, which rely on algae as a food source, die off, leading to death of larger fish, when their food source is killed off. These dead fish add to the climbing nutrient levels, which are not degraded by the now depleted supply of beneficial bacteria, causing an increasingly out-of-balance ecosystem.
This unbalanced system supports a growing population of aquatic weeds and more algae until the situation becomes worse than it was prior to the use of biocides. The dead fish, algae, and plant matter sink to the bottom, contributing to the sludge layer, which emits hydrogen sulphide and methane gases as obligate anaerobes take up residence, protected from further biocide use by the amount of sludge at the bottom. Without algae to add oxygen in the day, or beneficial bacteria to alter this cycle, the pond changes from aerobic to anaerobic respiration, killing the last of the remaining fish and other higher life forms. The pond now becomes a breeding ground for disease and parasites. By re-establishing a balanced system and possibly with a small amount of mechanical aeration, a long-term healthy environment is promoted.
Are these products "natural algaecides"?NO. The products do not directly attack algae, or any other LIVING entity, causing its demise. The special strains of bacteria and fungi are designed to clean up sources of excess nitrogen, phosphorus and other pollutants so that a healthy, natural environment can be restored.
If you want a swimming pool-like appearance, chemical biocides will give you the appearance you want, but forget having healthy fish, frogs, turtles and other natural residents of a healthy pond or lake.
Do these bacteria products require registration?NO. Generally naturally occurring, indigenous, and non-pathogenic bacteria do not require registration. In saying that all ETG products are AQIS approved and registered.
Are microbial products compatible with algaecides, antibiotics or pesticides?
Algaecides indiscriminately kill living microorganisms including beneficial bacteria. If you must use these, wait at least 14 days before applying microbial products to clean up the ensuing debris. These products are susceptible to most common antibiotics. If antibiotics are used for say fish, wait at least 48 to 72 hours after treatment to reseed the system with microbial products.
Why is the discharge of BOD & COD regulated?
Definition: BOD = Biochemical Oxygen Demand - The rate at which microorganisms use the oxygen in water or wastewater, while stabilizing decomposable organic matter under aerobic conditions. In decomposition, organic matter serves as food for the bacteria and energy results from its oxidation. The BOD test procedure measures the rate of oxygen use under controlled conditions, usually incubation in the dark at 20¡C for 5 days.
The above mentioned rules are not arbitrary. The discharge of pathogenic bacteria and excess nutrients in high BOD must be controlled to protect the ecology. Depositing large quantities of undigested nutrients onto the land upsets the balance of the nitrogen cycle. High BOD waste kills certain plants, leads to the growth of different plants on land leading to starvation for the indigenous populations of animals, birds, and insects. Leachate from land applications of this waste can pollute the water table and nearby rivers and lakes, where these excess nutrients support different phytoplankton which cannot be digested by the normal populations of fish, oysters, and shrimp, leading to massive death of aquatic life, which leads to death of the predators that feed on these species.
Other hazards of depositing high BOD waste into rivers include: the proliferation of pathogenic species of bacteria, the proliferation of Pfiesteria (a microorganism which has caused so much fish damage that entire rivers have been closed during certain seasons), and massive fish kills due to insufficient oxygen in the water as the high BOD waste uses up the oxygen that is present. The odours from high BOD waste attract pest and scavenger birds, insects, fish and animals, thus allowing these populations to increase at the expense of other species.
High COD waste containing chemicals, such as arsenic, cadmium, chromium, copper, lead, mercury, molybdenum, nickel, selenium, and zinc can poison the natural population of (unselected, unadapted) waste degrading bacteria, thereby breaking the food chain and leading to all the problems associated with a high BOD waste mentioned in the previous paragraph. High levels of these chemicals can also directly poison higher life forms. Permits are established limiting the amount of these toxins released to the environment in a given location.
Biosolids produced from a municipal facility or one that processes restaurant and animal farm waste should be sampled and tested monthly for the following pathogens to meet the specifications of this rule: fecal coliform, salmonella sp., enteric virus, viable helminth ova, inorganic pollutants, specific oxygen uptake (BOD/COD) and total fixed and volatile solids.
Is mechanical aeration necessary?A number of bacterial strains utilize dissolved oxygen in their digestive process. Mechanical aeration will enhance the effectiveness of these aerobic bacteria, particularly in aquatic environments. If the dissolved oxygen level of a water body is already very low and certain formulas are added which consume additional oxygen, a situation may be created in which there is inadequate oxygen for the fish - causing a fish kill. Many of the bacteria used are facultative anaerobes, so they can also work in anaerobic environments where nitrate is available as an alternative oxygen source.
Why aren't these products available on the shelf of retail stores?
The highly concentrated and specialized formulas require the services of trained distributors, backed by a qualified staff, to test and diagnose problem situations and prescribe the precise formula or combination of formulas, treatment schedule, and application method needed to achieve maximum results. As noted under the aeration and antibiotic questions, certain situations must be resolved, which can be anything from increasing the alkalinity to buffer pH to ceasing use of antibiotics before microbial products can succeed. For large projects, such as treatment of a river or canal, engineering reports are often generated detailing the treatment strategy, laboratory procedures to verify progress, and usage of equipment such as aerators and bioreactors.
What are the characteristics of microbial products?
The formulations can be manufactured in both liquid and dry media. These formulas are packaged in a dormant or vegetative state and have a 95% reactivation rate within their shelf life, which varies from six months to two years, depending on the product.
How are the products applied?
There are two ways : direct application and bio-filtration. Direct application is utilised in lake, pond and river treatment, aquaculture, soil remediation, drains, grease traps, composting, wastewater treatment, odour control and manure treatment. Product can be applied by pouring it into the system or onto waste, by spraying or by injection, as appropriate. Bio-filtration is used in aquaculture, groundwater and wastewater treatment where a biological filter is seeded with the microbial products and then the water runs through it.
How much product is needed?
Dosage is highly dependent on the pollution level, the waste volume and the specific product utilised. Dosage charts for aquatic products and wastewater treatment products should be linked to individual product bulletins.
How do microbial products compare economically?
Biological treatment with these products is far less costly than mechanical dredging, incineration or paying fines. Chemical treatments may be less expensive, when measured by the pound or gallon, but are stop-gap remedies and generally address only one aspect of contamination. Microbial products give greater value for the dollar spent because they treat the whole system. Natural systems regain their own capacity for self purification.
What nutrient balance is needed to degrade COD or BOD in different applications?
Aquatic applications, general waste treatment and anaerobic lagoons require a certain minimum nutrient balance for microbes to degrade the COD or BOD present. If the ammonia exceeds the level necessary for co-metabolism, then nitrifiers (contained in CF 1100, 1200, 1400, and 7110) may be added to handle the balance. If the phosphorus exceeds the level needed for co-metabolism, chemical binding, such as with dolomitic limestone, reverse osmosis or other means of filtration, may be required.
Carbon: Nitrogen: Phosphorus = 100:6:3 Phosphorus levels as low as 1 will also work in these environments.
Hydrocarbon remediation applications rarely have enough nitrogen and phosphorus present, so these must be added in proper proportion for the bacteria to co-metabolize them with the hydrocarbon waste. The level of nutrient supplementation must be precisely determined or pollution may be caused by excess nitrate or phosphate escaping into the environment.
Carbon: Nitrogen: Phosphorus = 100:10:5 Phosphorus levels as low as 2 will work in some applications.