SUBHASH MISHRA
Dhanbad, May 24: IIT Indian School of Mines (ISM) Dhanbad has developed a technique for the removal of fine particles and heavy metals from the effluents of coal washeries using Mustard and Moringa seeds as a bio coagulant.
The team has suggested the use of bio coagulants, including Mustard and Moringa Oleifera for the removal of high loads of suspended solids like coal fines, shale, slate, clay minerals and other impurities present in effluents of coal washeries.
The use of bio coagulant for the removal of unwanted wastes from effluents of coal washeries will help to avoid the challenges posed due to the use of chemicals for waste removal like post-processing of generated sludge as well as chances of leaching in the surrounding environment.
Prof Sukha Ranjan Samadder, associate professor of the Environmental Science Engineering Department who led the team said “ the coal fines which have a tendency to wash away will be recovered using bio coagulant.”.
He said the use of bio coagulant also helps to improve the quality of effluent water by removing the coal fines and other contaminants. The same water after treatment can be recirculated which can improve washing efficiency as water is cleaner.
The project is Coal India Limited (CIL) funded. Prof Samadder, who began the two-year research in March 2022 as principal investigator along with two co-principal investigators, Kumar Rajeev, chief manager (Mining), head of the environment department of BCCL; Dr Amartanshu Srivastava, deputy manager besides Khalid Ansari, research associate has completed the project
He said that “Fines having a size of less than 0.42 mm are generally responsible for forming slurry and if this fine is discharged untreated it will lead to deterioration of quality of underground water as well as the quality of natural water bodies.
He said, “heavy metals present in the coal washery effluents are also a cause of concern as they get accumulated in water, soil sediments and living organisms, therefore no effluent is allowed to be discharged outside the washery premises as per present environmental policies.”
He further said that the treatment of coal washery effluents in the Indian subcontinent is traditionally carried out with the help of conventional radial thickness which works on the principle of sedimentation and added that less has been made in the field of efficient effluent treatment and trapping of fines particles.
