Step-by-step explanation:
The pulp and the paper mill industry is intensive consumer of the water and the natural resources like wood and on return, discharging an ample variety of the gaseous, liquid and solid wastes to environment.
The wastewater which is being eliminated from pulp and paper industry usually contains high and tremendous levels of concentrations of the biochemical oxygen demand and the chemical oxygen demand and thus, shows high level of toxicity and a strong and deep black-brown color.