An in silico approach to prioritize emerging contaminants in Indian sewage treatment plants

Area of Science:

• Environmental Chemistry
• Risk Assessment
• In Silico Modeling

Background:

• Emerging contaminants (ECs) pose risks to ecosystems and human health.
• Prioritization of ECs is crucial for effective environmental management.
• Existing methods lack comprehensive assessment of environmental risk and removal efficiency.

Purpose of the Study:

• To develop a novel in silico approach for prioritizing emerging contaminants.
• To assess environmental risk, persistence, bioaccumulation, and toxicity (PBT) potential of ECs.
• To estimate the removal efficiency of ECs in sewage treatment plants (STPs).

Main Methods:

• Utilized in silico methods including risk quotient (RQ) calculation from measured environmental concentrations (MECs).
• Conducted PBT assessment following European Chemical Agency (ECHA) 2008 guidelines.
• Employed the STPwin model (EPI Suite 4.11) to estimate EC removal efficiency in STPs.

Main Results:

• Pharmaceutical and personal care products (PPCPs) and pesticides were identified as the highest-risk EC classes.
• Triclosan (PPCP) and dichlorodiphenyltrichloroethane (DDT) (pesticide) showed significant risk quotients.
• Pesticides and industrial chemicals are removable by conventional treatment; PPCPs, parabens, and phthalates require advanced STP modifications.

Conclusions:

• The developed in silico approach effectively prioritizes ECs based on environmental risk and removal efficiency.
• PPCPs and pesticides represent significant environmental concerns requiring targeted management strategies.
• Modified STP designs are necessary for efficient removal of recalcitrant ECs like PPCPs, parabens, and phthalates.