Toxic chemical poisoning of water bodies is one of the most common causes of water pollution. Dumped plastic bottles, tins, water cans, and other waste damage aquatic bodies, as seen in the example above. This leads to water contamination, which is harmful to not only humans but the entire ecosystem. In most situations, the result is merely harmful to local populations and species, but it can also have a worldwide influence.

Every year, over 6 billion kg of waste is dumped in the oceans. Other types of undesired items, in addition to industrial effluents and untreated sewage, are thrown into numerous water bodies. Nuclear waste to oil spills, the latter of which can render enormous areas uninhabitable, are examples.

Water contamination can be prevented and controlled in a variety of ways. To begin, more trees should be planted around water bodies because they naturally help to absorb and recycle pollutants. A few key points are mentioned below.

Control Measures of Water Pollution

There are numerous methods for controlling the water quality in a system. Here are a few examples:

1. Reducing the waste input’s effluent concentration by

• Wastewater treatment
• b) Process control in industrial plants
• Pre-treatment of wastewater constituents before release to sewer systems or different product manufacture for an industry to eliminate effluent constituents.

2. Controlling upstream point and nonpoint sources to reduce upstream concentrations.

3. Reducing the volume of wastewater by

• The volume of direct industrial discharge into the municipal wastewater system is reduced.
• Infiltration into municipal sewer systems is reduced.
• Waste volume reduction in industry through process changes.

4. Low-flow augmentation, such as releases from upstream reservoir storage or diversion from neighbouring water sources, increases upstream flow.

5. Increase the substance’s environmental, in-stream degradation rate

• This can be accomplished by redesigning the chemical so that natural heterotrophic bacteria in the stream can break it down more quickly. For example, synthetic detergents could be redesigned to limit foaming and downstream transport by increasing biodegradation rates. It may also be attempted to boost biodegradation rates in the manufacture of potentially harmful substances to avoid chemical build-up.

6. Environmental Regulations

• Control of harmful bacteria, viruses, and parasites falls into three major categories: control at the microbe’s input source, control at the point of water consumption, and control of the contaminated product. The usual main inputs of communicable disease organisms are municipal wastes that cause point pollution. Treatment of wastes without disinfection and disinfection with chlorination, ozonation, chlorine dioxide, and UV radiation can reduce such inputs.

Bathing limits on a temporary basis, as well as the installation of dikes and diversion projects to safeguard a specific area, are examples of water use controls. Chlorination or other methods of disinfection of water used for drinking water supply, treatment plants for tainted shellfish to allow bacteria to be removed before marketing, and delivery of high-quality bottled water during an emergency are all examples of product controls.

7. Biomass Harvesting

• To enhance wastewater treatment lagoons and treat chemical wastewaters, water hyacinth (Eichhornia crassipes) and other aquatic weeds are used. Not only has the water hyacinth been utilised to treat homes but also industrial effluent. Heavy metals including lead, cadmium, mercury, and nickel are easily absorbed, accumulated, and concentrated in it. Other research has looked into the ability of water hyacinth to absorb organic substances such as phenols and toxaphene. Even radioactive elements can be removed from effluents by water hyacinth, which is difficult to do otherwise.

As the metals are recovered from the effluents, the effluent is thoroughly cleaned. After treatment, the pH of the effluent was determined to be between 6.8 to 7.8, which is an ideal range for freshwater. Furthermore, the algal bloom is prevented, and the BOD and COD levels are reduced to the point where the effluent can be mixed with freshwater without causing harm.

The controlled use of water hyacinth in waste stabilisation ponds not only boosts the BOD removal capability of these systems, but also reduces the high total suspended particles often associated with sewage lagoons (Table 6.7). The gathered plant material can be used to make high-quality protein, biogas, fertilizer, and other goods. 

Pollution from effluent is reduced in a canal with water hyacinth.

8. Wastewater treatment

• The sewage treatment process produces irrigation water that is rich in critical elements such as nitrogen, phosphorus, and potassium, making it an excellent fertilizer. The practice of irrigating fish ponds with sewage to raise fish is popular in West Bengal. The reuse or recycling of sewage effluents for industrial uses is another intriguing feature. This is true for meeting the ever-increasing water demands of industrial facilities in large cities. A few businesses in Mumbai have already taken steps in this way, with treated sewage being utilised for air conditioning and other uses.

Conclusion

Water contamination can be controlled more effectively using a variety of ways. It is recommended to treat sewage waste before depositing it into bodies of water. By doing so, the original toxicity can be reduced, and the leftover compounds can be destroyed and rendered harmless by the water body itself. 

The Water Hyacinth is a one-of-a-kind plant that can absorb dissolved toxic chemicals such as cadmium and other metals. Putting them in places where pollution is a problem will considerably reduce the negative repercussions.

Precipitation, the ion exchange process are some chemical processes that aid in the treatment of water pollution. Reusing, reducing, and recycling as much as possible will help to mitigate the effects of water contamination.