With reference to the role of biofilters in Recirculating Aquaculture System, consider the following statements:

1. Biofilters provide waste treatment by removing uneaten fish feed.

2. Biofilters convert ammonia present in fish waste to nitrate.

3. Biofilters increase phosphorus as nutrient for fish in water.

How many of the statements given above are correct?

Consider the following statements regarding mercury pollution:

1. Gold mining activity is a source of mercury pollution in the world.

2. Coal-based thermal power plants cause mercury pollution.

3. There is no known safe level of exposure to mercury.

How many of the above statements are correct?

With reference to green hydrogen, consider the following statements:

1. It can be used directly as a fuel for internal combustion.

2. It can be blended with natural gas and used as fuel for heat or power generation.

3. It can be used in the hydrogen fuel cell to run vehicles.

How many of the above statements are correct?

Consider the following statements:

Statement-I: The soil in tropical rainforests is rich in nutrients.

Statement-II: The high temperature and moisture of tropical rain forests cause dead organic matter in the soil to decompose quickly.

Which one of the following is correct in respect of the above statements?