What happened to the Rhine River?

Ruining of a natural cycle

What is the responsibility for this situation? The physical causes are basically simple. Under normal circumstances, a good natural bicycle should make a river "self-cleaning". The cycle begins when aerobic bacteria in the water use oxygen to break down organic waste into chemicals that act as nutrients for the algae. Small animals called zooplankton eat algae. Small fish eat zooplankton. So the big fish eats the little fish. When the big fish dies, the aerobic bacteria start the cycle again. This process works both for natural waste such as dead fish and for much of what people throw in the water.

But what happens when industrial factories throw a lot of waste into a river? This forces aerobic bacteria to work harder to break them down into nutrients or other substances that are harmless to aquatic life. Due to the added stress, these bacteria consume more oxygen than is naturally returned to the river. Tens of thousands of tonnes of waste that is broken down every day by the Rhine are chemicals that bacteria cannot break down. Due to these factors, the self-cleaning cycle is interrupted. The water gradually becomes dirty and animals and plants die.

Unfortunately, this has been the fate of the Rhine for more than four decades. Ludwigshafen am Rhein is the largest chemical plant in Europe. According to its own information, this plant sold about 314 million cubic meters (240 million cubic meters) of wastewater in 1973. This number has now grown to almost 334 million cubic meters (255 million cubic meters). In addition, the Rhine carries three tonnes of arsenic, 450 kg of mercury, 60,000 tonnes of potash salts and large quantities of other toxic substances every day.

Some clean-up works

There is a great need to fight against the pollution of the Rhine, nearly 20 million people receive drinking water from this river (after the water has been filtered, and the industry consumes about 20 billion cubic meters (15 billion cubic meters. Cubic meters) of water directly from the Rhine each year. Is there a way to improve the purity of the water?

Some good results have been obtained in wastewater treatment plants. They handle the garbage before it is thrown into the river. In one process, wastes are transported through "grain channels" through which heavy inorganic materials such as sand and gravel can settle.

The drain then goes to a large reservoir to which air is added. This allows aerobic bacteria to thrive. The mixture then enters an aeration tank where more compressed air is pumped. At this stage, "activated sludge", which is a solid residue of a previously treated residue, is added. This substance also contains large amounts of aerobic bacteria which “dissolve” suspended solids in wastewater.

In the next step, the mixture reaches a clarification tank, into which the decomposed solids flow. These solids loaded with aerobic bacteria form activated sludge. This is removed from the bottom of the septic tank. The liquid that escapes from the tank is chemically treated to kill dangerous bacteria. After that, it can be discharged into the river without causing contamination. As mentioned above, a part of the activated sludge removed from the clarification tank is added to the activated sludge tank in order to accelerate the reduction of the additional wastewater loads.

Another method of treating wastewater involves "filtration filters". Liquid waste is filtered from a tank through a stone or slag filter. This filter does not work as a strainer. Instead, it provides a surface on which aerobic bacteria can grow. When the wastewater passes through the filter, the bacteria cause the organic waste to decompose.

Obstacles that hinder progress

No one expects these sewage treatment methods to return the Rhine to its original purity. Cleaning 100% of the trash would be too expensive to justify a full inspection. For example, a sewage treatment plant at the chemical factory in Ludwigshafen only cleans part of the waste. But did the factory cost 450 million marks to build? * An additional 70 million marks per year are required for maintenance, so energy consumption corresponds to a city with 50,000 inhabitants.

Although excess activated sludge may be useful as a fertilizer, there is an additional cost of disposal. Few are likely to incur the costs required for complete sewage treatment.

How about the daily disposal of tens of thousands of tonnes of chemical waste that cannot be biodegradable? Some cleaners are particularly troublesome. They cause lots of foam that stays in the water for a long time. And even if the foam eventually wears out, detergents are still toxic pollutants. Oil is also a criminal. Once it enters a water source, the oil is difficult to remove. Sometimes it goes into drinking water, making it unusable.

Due to high costs and other problems, many believe that the best way to reduce pollution in the Rhine is to reduce the amount of pollution deposited there. However, there is some hope for significant progress in this direction. Why? Why many should lower their standard of living. Unfortunately, most people prefer to tolerate polluted water rather than give up the conveniences of modern industry. In addition, merchants who see the company's profit as the primary purpose of life are protected from efforts to reduce industrial production.