Research Projects

The rationale of research: Water reuse is essential due to global water scarcity, with greywater offering a promising alternative. However, emerging contaminants like inorganic nanoparticles (NP) and nanoplastics (Npl), along with traditional pollutants in greywater, pose significant risks to both human health and the environment. There is limited understanding of their occurrence, fate, and removal from greywater. While conventional treatment systems can reduce these contaminants, they are ineffective in eliminating them to safe levels. Thus, there is a need for modifications in existing technology for testing removal efficiency for a mixture of NP and Npl. This study aims to investigate the removal of a mixture of NP and Npl in conventional treatment systems. By modifying water chemistry, adsorbent properties, and colloidal particle characteristics, the study seeks to enhance removal efficiency without the need for entirely new treatment infrastructure. The approach combines Coagulation-Sedimentation-Filtration with Ultrafiltration (CSF-UF) by modifying the surface properties of coagulants, adsorbents, and membranes to remove both NPs and Npl from greywater effectively. There is a need to develop guidelines and standards for the maximum allowable concentrations of NP and Npl in greywater for these ECs, which can be achieved through a mixture risk assessment of greywater. Scientific Objectives: The overall purpose of the proposed project is to develop a decentralized treatment system consisting of modified conventional and advanced treatment units for NPs and Npl mixture removal from greywater and make it fit for reuse. Hypothesis: The study will be accomplished by conducting hypothesis-driven study which includes 1) Greywater contains Np and Npl 2) a conventional coagulation-flocculation-sedimentation(CFS) system is not efficient in the removal of mixture of contaminants, 3) modified chitosan coagulant and membranes will aid in removal of NP+Npl, 4)Treated greywater will not pose any health risk if reused. Experiments: The overall approach of this study is experimental. The flow of the experimental work will be 1) Collection and characterization of greywater from household; 2) Checking efficiency of the CFS system for removal of NPs and Npl (with and without NPs and Npl modification); 3) Modification of conventional units by modifying chemical and surface properties of coagulant, sand, and nanoparticles, 4) development of CSF-UF hybrid treatment system. Research Significance: The proposed research aims to characterize emerging contaminants in greywater, optimize conventional water treatment for better pollutant removal, and develop proof-of-concept technology for removing NP+Npl mixtures. The outcomes will contribute to greywater reuse, household and community-level treatment systems, and establish risk-based guidelines for NP and Npl usage and release. This will benefit the scientific community, the public, regulatory bodies, and industries.