We continue to hear about that the wastes that derive from human activity are polluting and dagerous for the environment. Why does this happen?
Some of them are consisted by substances dangerous for the environment ("The poison is dependent on its dose"). Solid wastes deriving from agriculture are commonly used as animal feed and/or fertilizer. What happens then with liquid wastes?
Some of them are consisted by substances dangerous for the environment ("The poison is dependent on its dose"). Solid wastes deriving from agriculture are commonly used as animal feed and/or fertilizer. What happens then with liquid wastes?
Despite the fact that there is legislation (E.U.) saying that "the one polluting is obliged to pay for that act", in most of the cases this legislation is not maintained. As a result, numerous liquid wastes are thrown in the environment (nearby land, rivers, lakes, sea) without any prior treatment. In fact though, why is this a problem? The aforementioned wastes are rich in organic matter. The "carry" high organic load. Obviously nature has a solution for that. In order to break ("degrade") this load, cares to offer those wastes oxygen. Oxygen which is available in dissolved form into the water. |
The problem is double. On one hand, if this process occurs under natural and spontaneous way it lasts too long. On the other hand, the wastes volume is too big that the concentration of water dissolved oxygen is not enough to biodegrade their polluting load; resulting in the binding of the whole diluted oxygen which is available in water. Thus, no quantity is excess for the needs of all aquatic organisms. And whats is the outcome? Eutrophication phenomena, dead fish, bad odours etc. If the uncontrollably discarded into the water waste, is of dark colour (like olive mill wastewaters), then a dark film is created which is impenetrable from sunlight. Thus, the energy of the sun never reaches at algae, interfering photosynthesis and the valuable oxygen stops to be produced.
The need for human intervention so as to manage the produced wastes is more than obvious. This can be achieved by various ways:
If the treatment result may include useful compounds produced (commercially exploitable) then double the profit. Treatment and utilization simultaneously!
Imagine (like happening in Brazil), using molasses (a low cost by-product deriving from the production of sugar cane) as raw material for the production of bio-ethanol via alcoholic fermentation (exactly as grape must becomes wine). We end up with an ecological bio-fuel considered as renewable energy source which at the same time reduces our oil dependence (coming with any financial and social subsequent effect).
We are talking about a sustainable plan, which offers profit, is more attractive and may alter the indifferent behaviour towards environment. Even that way...
- Chemical processes (pollutant degradation by chemical reactions). This approach is considered to be not enough compatible with the environment as the process residues may end up as dangerous as the initial pollutants. Moreover this kind of procedures are cosnidered as uneconomical.
- Physical processes. The waste treatment take places under physical processes (filtration, precipitation, condensation etc.). Let's imagine a glass of water containing blurred water due to soil added. If this glass is left calm (especially in the fridge), a mud sediment will be created at the bottom of the glass and a clear liquid as supernatant. We have managed to treat it and divide the precious water from the contaminant soil. Nevertheless we need to spend energy to achieve that. Is this sustainable?
- Biological/Biotechnological processes. Biotechnology may "transform" the undesirable properties of the wastes and create a non pre-existing desirable result. That kind of processes are considered to be more environmental compatible and potentially more economic.
If the treatment result may include useful compounds produced (commercially exploitable) then double the profit. Treatment and utilization simultaneously!
Imagine (like happening in Brazil), using molasses (a low cost by-product deriving from the production of sugar cane) as raw material for the production of bio-ethanol via alcoholic fermentation (exactly as grape must becomes wine). We end up with an ecological bio-fuel considered as renewable energy source which at the same time reduces our oil dependence (coming with any financial and social subsequent effect).
We are talking about a sustainable plan, which offers profit, is more attractive and may alter the indifferent behaviour towards environment. Even that way...