Settling of material is a common phenomenon, especially where clay is used for soil and construction and in both cases, the settling will take a long time. In the case of plaster on concrete walls and ceiling, the settling takes between seven to ten years and it can increase to up to twenty years if the temperature of the earth at that place remains constant. The average temperature of the earth is about seventy degrees Fahrenheit and this duration is for a period of about five to ten years.
Settling of soil and building can also be caused by different climatic changes. During summer time, the temperature goes up and during the winter season the temperature goes down. The nature of the land plays an important role in determining the settling of the land. In the absence of the clay layer in the bedding layer, the process of thermophilic aerobic digestion does not take place and the soil settles slowly.
A slow settling of the land can be caused due to high temperature. When there is high temperature the land settles faster than the process of thermophilic aerobic digestion. There are many other causes for the occurrence of thermophilic aerobic digestion. Two of the major factors which have a great contribution towards the occurrence of the process of land settling are the presence of calcium carbonate or gypsum and the presence of soluble Solids. These two factors tend to reduce the solids content in the soil, thereby affecting the process of settling of the land.
Another factor responsible for increasing the settling of the land is the inappropriate use of muddiness in the preparation of building materials or the improper type of fertilizers or other nutrients used for irrigation. It is found that the use of phosphoric acid and gypsum can increase the amount of sludge released during land sowing and the amount of bioilluminating bacteria present in the plant roots. These factors inhibit the growth of microorganisms responsible for the decomposition of plant material and reduce the quantity of dissolved organic compounds (FOC).
The introduction of bioreactors into the agricultural field has helped in reducing the wastes like feed and seed as well as fertilizers and nutrients. Bioreactors are mechanical systems which mix together the sludge from the different layers of the soil. The term ‘bioreactors’ refers to any of the following – an active layer, an inactive layer and mixed sewage sludge. The term ‘mixed sewage sludge’ refers to waste materials such as grain, oilseeds, pastures and other feeds.
The production of feed, seed, oilseeds and other feeds through bioreactors depends on four factors. First of all, there is the condition of the land. The quality of the soil determines the type of livestock it can support and the amount of fertilizer and pesticides that it needs. In addition, the condition of the surface and the quality of the air to determine the quantity of nutrients that need to be applied and the cost of these activities.
There are two types of bioreactors used for the production of feed. The first type of bioreactor is a closed bioreactor – it contains no air or live organisms and the waste being produced is contained within it. The second type of bioreactor is an open bioreactor – the waste coming out of it contains live organisms but no air or oxygen. So, the average and standard deviation of these four factors will give rise to a set of parameters commonly referred to as Feeding Sludge Factor (FSF) and Anaerobic Soil Selection Index (ASI).
The FSF is the average and standard deviation of the feeds coming out of the four bioreactors. The ASI is the ratio of feed input to mass produced by the bioreactors, i.e. the number of units of aerated sludge per unit of volume of soil that is used for livestock feedings. Feeding soil additives can be added to the aquifer to enhance the performance of the four bioreactors and to increase the FSF and ASI values, thus providing the highest quality of tilapia for the intensive agricultural market.