Tag: pollution - a rising environmental problem

Iron is particularly problematic in paper manufacturing because it causes staining and discoloration of the paper product.

Detergents that are released from the domestic sewage, as well as the industrial effluents, are the causative pollutants because these result in the increasing the inorganic mineral quantity in the water body. Because of this, the eutrophication occurs. The dissolved oxygen in the water body is decreased and the aquatic life suffers from the hypoxia. Plastic, glass junk and iron junk persist in nature as they are non-biodegradable. Their downhill causes are less as compared to the detergents.

Detergents are the chemicals that have an efficient cleaning ability due to the surfactants present in them. In order to provide the whitening effect, detergent contains bleach. Their are optical brightening substances called fluorescers also present. The perborates are added in the detergents as they provide effective oxidizing property. However, all these chemical are nondegradable in natue and tend to persist in the environment. Hence, the correct answer is ‘All of the above’.

Thermal pollution refers to the water pollution caused by the discharge of the hot industrial effluent in the water body that destroys the ambient temperature of the water body. The thermal pollution is a major water pollution near the coal power plants that use water as the coolant so that it absorbs the thermal energy from the thermal plants and then the hot water is released in the nearby water body. The rise in temperature of the water causes severe adverse effects to the aquatic life.

The eco-friendly detergents are free from the added chemicals, instead they have enzymes to catalyse the reactions. They do not contain phosphates, bleaches, synthetic perfumes, brightening chemicals etc. They contain lipases and proteases that break down the fats and proteins, so they are effective in stain removal. Hence, the correct answer is 'Phosphates and bleaches'.