Soil Remediation

By J. C. Hayes

Bio remediation is not new. Microorganisms have been breaking down chemicals in their environment to use as a food source since the first microbe evolved on our planet over four billion years ago. The atmosphere in which early bacteria grew and flourished was a toxic chemical sea of water and gases such as methane, carbon dioxide, nitrogen, ammonia and hydrogen, as well as deadly carbon monoxide, hydrogen sulfide and hydrogen cyanide. The young earth’s atmosphere contained little or no free oxygen, therefore oxygen-breathing organisms did not exist as they do today. Temperatures in excess of 100 C (212F) on the planet were an additional factor making the atmosphere inhospitable to all but the most heat loving microbes.

Development of present day microbes, including anaerobes, facultatively anaerobic and aerobic species was dependent on the changes in microorganisms which would produce oxygen by harnessing the suns energy and using the abundant carbon dioxide gas in the atmosphere as a carbon source in the process of photosynthesis. Therefore, on early earth, there were microbes which could utilize no oxygen and would die in its presence since oxygen produced toxic free-radicals inside the cell. And there were microbes which had evolved to produce and tolerate toxic oxygen compounds and paved the way for those of us who cannot live without some oxygen in the air we breathe (Brock, 1991).

In an effort to establish niches of their own, certain ancient microbes developed ways to live in both worlds and thus were able to live with or without oxygen. These organisms are known today as facultative anaerobes. As mentioned above, bio-remediation is not new, although the present day industrial uses of it are relatively new, having been “developed” within the last 25 years. There uses are sometimes controversial to a public which has been taught that “the only good microbes are dead microbes”.

However, nothing could be further from the truth… other than a relatively few pathogenic strains of microorganisms, there are over 10,000 known species which are normally harmless to human beings. HOMO SAPIENS are the unknowing recipients of countless beneficial chemical reactions carried out by microbes. These include oxygen production, nitrogen fixation, vitamins, antibiotic production and the break down of numerous compounds in our soils and drinking water that would otherwise be toxic to human life. Bacteria are also responsible for the decay and degradation of all forms of dead organic matter (both plant and animal).

Heartland Microbes contains a broad and diverse population of live, naturally occurring beneficial microorganisms. These natural degraders are environmentally safe and literally breathe life back into most polluted and contaminated soil and water. The mixture of microorganisms in Heartland Microbes is similar to the first primordial mixture of microorganisms found on earth, in that it is composed of all three types of microbes: those that require oxygen (aerobes), those that require no oxygen (anaerobes) and those that can live with or without oxygen (facultative anaerobes).

Heartland Microbes is a liquid culture of living microorganism capable of performing a variety of bio-degradative tasks. Such tasks include the reduction of salts in the soil, thus reducing Hardpan, the breakdown of compounds such as fertilizers, diesel, gasoline, oil, pesticides and hydrocarbon spills on oil field production sites. Other tasks include the promotion of enzymes, vitamins and antibiotics.

Many of the above tasks constitute a definition of bioremediation, which is the process by which microorganisms are used to decontaminate toxic substances in water and soil. By the addition of a mixture of microbes which have the ability to degrade toxic substances (petroleum spills, highly concentrated salts and other toxic waste (Fry, et al 1992). Many contaminated sites may be cleaned up on site. The decontaminating microorganisms, the beneficial microbes and fungi, are now being used as a natural remedy to clean up toxic waste sites and to reduce hardpan in America’s farmlands.

While there are many biological products on the market which contain only a single or a few microbial types, Microbes and Organics provides a unique blend of microorganisms in a liquid form called Heartland Microbes. The microbes in Heartland Microbes work together as a family, resulting in the beneficial breakdown of contaminates in the soil and water. The complex mixture of naturally occurring microorganisms found in Heartland Microbes have been grown in a culture together for over 30 years, The mixture contains no genetically engineered microbes.

Because the microbes in the Heartland Microbes mixture are grown under conditions of starvation, its members begin the degradation of many contaminates as soon as they are introduced into the soil or water. A starved condition in human beings is undesirable, whereas with microbes, starvation is a normal part of their life cycle. This is the state that most microbes are in whether they are in soil or water when conditions of nutrition are typically limited (Kjelleberg, 1993). Since the microbes in Heartland Microbes are in a state of starvation before application as a biological control, the microorganisms are naturally ready to devour any food source given to them, whether it be crude oil from a broken pipeline in Alaska or in South Texas. The microbes find these “undesirables” excellent sources of carbon and energy (organic matter).

Petrochemicals are a ready source of carbon for the microbes, but such diets may need to be supplemented with nitrogen, phosphorus and other minerals. These can usually be found in fertilizer. Since the breakdown of petroleum is done more quickly under aerobic conditions, addition of oxygen enhances the rate of degradation (Fry, et. Al., 1992). With the seepage of contaminates deep below the surface of the soil, some method of piping microbes, nutrients and oxygen down to the level of the contamination is needed to speed up the degradation process. Other methods of supplying oxygen to the contaminated areas include: injection of calcium peroxide or hydrogen peroxide, which provides hundreds of ppm of oxygen to the oxygen depleted areas (Raymond, et. Al. 1986; Laws, 1990). With the hydrogen peroxide, care must be taken not to use too much as the microbes can be killed.

However, many petroleum spills occur in open waters and on the surface of the land where is an abundant supply of oxygen. On January 19, 1990, the world witnessed the largest deliberate oil spill ever seen. That day in January, Iraqi troops spilled 500,00 tons of Kuwaiti crude oil into the Gulf. This act of biological warfare lead to the forecasts of doom for Kuwaiti’s future, and the world watched as oil slicks the size of small nations spread over the waters of the Gulf, contaminating coastlines along the Saudi Arabian shore. Instead of annihilation of all life in the polluted areas as predicted, scientists discovered millions of organisms thriving – microbes growing in blue-green mats within the seas of crude oil. This consortium of microorganisms was made up of naturally occurring blue-green bacteria which had associated with millions of other marine microbes to begin the first critical steps of recovery from the environmental war crime in the Gulf (Nature, Thomas Hopner, 1992).

It was the mixture of several types of microbes (a consortium) that enabled others of the group to initiate the first steps of the cleanup process. At the outset, the blue-green bacteria (cyanobacteria) provided needed nutrients and a safe haven within their microbial mat for the microbes to live and work breaking down the crude oil. In return, the cyanobacteria benefited by having hydrocarbons broken down into a steady supply of nutrients for their own use (Hopner, 1992). With many microbial types working together, the task of finding another meal was done more quickly and efficiently.

A similar consortium such as this makes up the microbial mixture of Heartland Microbes. Upon re-introduction of Heartland microbes into their natural environment in water or soil, the microbes are able to use almost any contaminant as a food source – even contaminates such as diesel fuel and other petroleum products. Man has been adding foreign chemicals (xenobiotics) to the soil for many years, substances such as solvents, pesticides, herbicides and other compounds. In the early 1960s it was discovered that members of the pseudomonas group of microbes were the primary degraders of chemicals in the soil and water. There are many such microbial species in the Heartland Microbes mixture which can degrade troublesome chemical mixtures. Some of the toxic compounds degraded by Heartland Microbes are discussed below:

BTX (Benzene, tuloene and xylene) are commonly found aromatic chemicals. These aromatics are found in diesel fuel, gasoline and jet fuel. These chemicals are used by certain microbes as a source of food and energy. The Heartland Microbes mixture contains many such microbes. As the fuel is broken down into smaller, simpler by-products by one group of microbes, other microbes in Heartland Microbes are then able to complete the work of breaking it down completely to carbon dioxide and water in a process known as mineralization (Fry, et. Al. 1992).
Heterocyclic Organic Compounds (oil, diesel, pesticides, herbicides): are broken down by microbes at the surface level where there is an ample supply of oxygen. The microbes degrade petroleum products particularly well where there is a supply of oxygen which is required for the breakdown process. However, microbes in deep soil do not work as quickly as their aerobic counterparts. The degradation process by microbes in petroleum contaminated soils deep beneath the surface becomes more difficult, but not impossible. To speed up such degradation, the addition of microbes and fertilizer in a piped in aeration system is needed. The rate of degradation depends on the soil type, pH, temperature, and the type of contamination being degraded. Two components, namely the appropriate microbes and a favorable environment, are required for the successful biodegradation of contaminants in water or in a terrestrial environment.

Requirements for the successful breakdown of contaminants on site (in site) are:

Some microbes in the mixture must have the ability to degrade the contaminant present.
Microbial mix must have the ability to be grown and stored prior to use with a long shelf life.
Microbes must be able to survive and function in the environment in which they are introduced.
Some microbes should be able to fix nitrogen as an additional benefit.
Microbes must have the ability to grow from small inoculum levels.
The microbes themselves should produce not toxic effects on the environment (Prescott, 1993).

Conditions of the environment which must be met include:

A food source (preferably the contaminant of choice) and other supplemental nutrients (nitrogen, phosphorus, iron and vitamins) must be available in the same physical location as are the microbes.
Chemicals and compounds toxic to the microbes must be present from the readily degradable contaminant by some microbes in the mix (i.e. heavy metals inhibit the growth of some, but not all microbes).
Appropriate levels of oxygen must be maintained for the degradation process to occur, as in petroleum breakdown deep below the soil surface.

Albert Einstein’s definition of environment was “anything which isn’t me” (Fry, et. Al. 1992) which pretty well covers the far-reaching range of possibilities of microbial action in the environment. But just as each of us has our own place to exist in the world, so too, does a single microbe and its environment is just as critical for the microbes as ours is for us.

In the mixture of microorganisms in Heartland Microbes there are many different types of microbes. Upon application of Heartland microbes to contaminated soil, the microbes begin to find a place of their own where they can live, divide and grow in numbers. To do this successfully, a microbial cell needs proper nutrition – certain microbes require different nutrients from those of others. It is in this way that some of the microbes in Heartland Microbes have developed the unique ability to break down compounds that some of the others cannot. Thus, the population changes and fluctuates, allowing other microbes in the Heartland Microbes to use the by-products of the first round of degradation as a source of food. The symbiotic, or mutually beneficial, relationship of the different microbes may seem unrealistic since there is major competition for food among all microbes. But one type of microbe can initiate the breakdown of contamination as a food source rarely used by most microbes to produce by-products which in turn become food for other microbes. Then a mutually beneficial relationship develops. This is , typically, what occurs with the families of microbes in Heartland Microbes. With such a large diversity of microbes for specific-use applications, increasing cost and possibly having an unfavorable environmental impact.

Soil Profile for Microbial Growth

The difference in soil types are varied, Thus, it is impossible to characterize levels at which microbes and other microorganisms flourish or flounder. Since there are major chemical and physical differences between soils in different climatic areas, the microbial populations also vary accordingly. However, in a “healthy” soil, there may be from 106 to 109 power of microbes per gram of soil in a given soil sample – higher populations than those microbial numbers are found in fresh water of in the ocean (Atlas, 1984). A lot also depends on plant growth, as there are much higher numbers of microbes found in association with plant roots (the rhizosphere) and in the organically rich surface layer (A Horizon) than in the underlying mineral layers (B Horizon) and areas above the bedrock (C Horizon).

Heartland Microbes microorganisms primary composition includes Bacillus, Pseudomonas, Azotobacter, Azospirillium, Rizobium and soil borne Cyanobacteria. BioZymes includes aerobic, anaerobic and faculatative anaerobes that are naturally occurring with no genetically engineered organisms and no pathogens. Although the above microbes are the primary composition of Heartland Microbes, there are more than 18 families and over 125 species in Heartland Microbes. Heartland Microbes is a unique blend of indigenous microorganisms capable of breaking down carbon-based hazardous and non-hazardous chemicals, both chain and aromatic in nature. Heartland Microbes has a broad and divers use in bio remediation of chemicals spills. Heartland Microbes eliminates the “dig and haul” method of cleanup in most cases. If the spill is in an area where it is of no danger to humans or animals, it can be remediated on site. Heartland Microbes is capable of remediating a contaminated site down to acceptable levels or below. Heartland Microbes in not a laboratory engineered (specific use) microbial solution. Another area of remediation that Heartland Microbes is of great use is in the breakdown of animal and human waste. Whether it is a septic system, city municipality or an animal waste lagoon, Heartland Microbes will reduce solids, odors and toxins.