Risk assessment of solute leaching from paper industry effluents in heterogeneous soils of seemanchal

The Seemanchal area of Bihar has traditionally been a rice-cultivating region. Large-scale rice cultivation generates substantial agricultural residues, such as paddy straw, husk, and other organic waste, as byproducts. These small industries often dispose of their effluents (wastewater) directly into open fields, posing a risk of solute leaching into the ground. This study assesses the risk of solute leaching into soil and groundwater using HYDRUS-2D. Solute transport simulation results show that it takes solute around nine days to transport from the ground surface to the water table. It is also observed that the cumulative concentrations of the two solutes studied at the water table, biological oxygen demand (BOD) and calcium compounds (Ca+), are observed to be 1294 mg/l and 841 mg/l, respectively. It is concluded that, with the water table at such a shallow depth, there is a high risk of contamination of groundwater due to leaching of effluent solutes. The study highlights that the wastewater from small paper industries needs to be treated before disposing of it on land or in water bodies, and also, there is the need for enforcement of compliance with CPCB (2003) recommendations.