(a) Effluents and harmful gases are the main wastes which are produced in a fertiliser factory.
(b) Treatment of Polluting Gases:
For reducing the amount of gaseous pollutants, catalytic converters should be fitted in the chimneys.
(c) Effluent Treatment:
Effluent from the factory should be sent to effluent treatment plant. Sedimentation, flocculation. filtration and chlorination are the various steps of effluent treatment. Once effluent is treated, the clean water can then be sent to nearest water bodies. The sludge can be allowed to decompose which can later be used as manure.

Some of the harmful effects of agricultural practices on the environment are as follows:
Climate Change : As farming means growing a selected number of species on a large tract of land, it promotes monoculture. Thus farming affects the biodiversity of a region in a negative way.
Deforestation : Clearing of forests for agriculture has resulted in loss of habitat to wildlife. Deforestation has also affected the natural recharge process of ground water.
Soil degradation : Intensive farming robs off the soil of its nutrients. In the long run, it can lead to soil erosion and finally to desertification.
Water shortage : Over exploitation of groundwater for irrigation has resulted in acute water shortage at many places.
Pollution : Use of synthetic fertilisers and pesticides creates soil pollution, water pollution and air pollution.

The harmful by products are gases such as SO₂ and NO. They cause extensive air pollution and are responsible for acid rain.