Journal of Environmental Management 266 (2020) 110572 Available online 24 April 2020 0301-4797/© 2020 Elsevier Ltd. All rights reserved. Research article An overview of organic matters in municipal wastewater: Removal via self-assembly flocculating mechanism and the molecular level characterization R.T.V. Vimala a , J. Lija Escaline a , Kadarkarai Murugan b , S. Sivaramakrishnan a, * a Department of Biotechnology, Bharathidasan University, Tiruchirappalli, Tamil Nadu, 620024, India b Department of Zoology, Bharathiyar University, Coimbatore, Tamil Nadu, 641046, India A R T I C L E INFO Keywords: Sewage waste High-throughput techniques Zebra fish Comet assay Organic matters Contaminants ABSTRACT On considering the critical issues in attaining stringent water quality standards and not creating any environ- mental impacts, we focused for the first time the economically feasible, emerging technology known as Self- assembly flocculating (Saf process). In which, the study investigated the applicability of bioflocculant (a biopolymer-self-assembly in nature) act as a surrogates on relying the removal of broad spectrum of substances under optimized conditions (Dosage: 90 mg/L; pH: 7; CaCl 2 ). On using different techniques, the results have proved in removing the organic matter such as pharmaceuticals (Gentamycin, Cholecalciferol, Fluvoxamine, 3- OH Desogestrel, and Pheniramine), endocrine disturbing compounds [Phthalic acid, Benzene, 1, 2, 4 -Trime- thoxy-5-(1-Propenyl)-, Benzene, 1, 2-Dimethoxy-4-(2-Propenyl)-, 1, 2-Benzenedicarboxylic Acid, 3-Cyclohexen- 1-ol], fluorescent components (Polysaccharide like material), and others. The toxicological assessment of self- assembly bioflocculant implemented on zebra fish were statistically correlated [r ¼ 0.95, p < 0.01 and 0.05 for P 1 WW; r ¼ 0.91, p < 0.01 and 0.05 for P 2 WW] and [r ¼ 0.7 5, p < 0.05 for P 1 WT; r ¼ 0.095, p < 0.01 and 0.05 for P 2 WT]. This integrated approach supplemented further information of zeta potential ( 16 mV in P 1 WW and  14.6 mV in P 2 WW decreased to  1.05 mV and  1.56 mV) with particle size distribution to explain via Saf process. In this research, the new insight has established non-toxic, self-assembly, biodegradable, bioflocculant for effective bioremediation. 1. Introduction The organic matter (OM) dissolved in municipal wastewater, con- tains a mixture of recalcitrant compounds (Carstea et al., 2014; Huang et al., 2010) such as endocrine disrupting compounds (Kasprzy- k-Hordern et al., 2009), pharmaceutical compounds, disinfection by-products, personal care products (Yan et al., 2014; Martin et al., 2012; Miege et al., 2009), metabolites (Schaider et al., 2017; Wang and Kannan, 2016) which can be released into the water bodies through discharge. Therefore, it causes major threats to the ecosystem through its discharge without pre-treatment. In order to achieve wastewater reclamation, battery of complementary techniques and advanced treatment methods are required to define its structural and functional character efficiently due to its biochemical difficulty (Kucharzyk et al., 2017). In modern decades, bioflocculants, a complex high-molecular-weight mixture of polymers secreted by microorganisms have attracted significant scientific and world-wide attention, especially in wastewater treatment, due to their biodegradable in nature, hazard- less, and lack of secondary pollution (Guo et al., 2016; Sun et al., 2015; Sheng et al., 2010). Moreover, this kind of polymers (bioflocculant) usually creates excellent standard water qualities such as COD, BOD, total organic carbon (TOC). But, those parameters alone do not involve in assessing the toxic effects of all the contaminants of municipal water (Kjeldsen et al., 2002). The molecular level characterization of the overall contaminants are of significant for improving the knowledge about the wastewater treatment processes (Huang et al., 2010). There- fore, various advanced characterization techniques [High performance gas chromatography-mass Spectrometry (GCMS) (Jadhav et al., 2010); High resolution liquid chromatography (HR-LCMS); Fourier transform infrared spectroscopy (FTIR) (Patowary et al., 2016); X-ray photoelec- tron spectroscopy (XPS); X-ray Diffraction (XRD) (Wang et al., 2017); Energy dispersive spectroscopy (EDAX) (Karthikeyan et al., 2013); * Corresponding author. E-mail address: srkrishnan@bdu.ac.in (S. Sivaramakrishnan). Contents lists available at ScienceDirect Journal of Environmental Management journal homepage: http://www.elsevier.com/locate/jenvman https://doi.org/10.1016/j.jenvman.2020.110572 Received 21 August 2019; Received in revised form 2 April 2020; Accepted 4 April 2020