Journal of Environmental Management 274 (2020) 111156 Available online 12 August 2020 0301-4797/© 2020 Elsevier Ltd. All rights reserved. Research article Impact of hydrochar and biochar amendments on sorption and biodegradation of organophosphorus pesticides during transport through Danube alluvial sediment Marijana Kragulj Isakovski a , Sneˇ zana Maleti´ c a, * , Dragana Tamindˇ zija a , Tamara Apostolovi´ c a , Jelena Petrovi´ c b , Jelena Triˇ ckovi´ c a , Jasmina Agbaba a a University of Novi Sad, Faculty of Sciences, Department of Chemistry, Biochemistry and Environmental Protection, Trg Dositeja Obradovi´ ca 3, 21000 Novi Sad, Serbia b Institute fot Technology of Nuclear and Other Mineral Raw Materials, 86 Franchet d’Esperey St., 11000 Belgrade, Serbia A R T I C L E INFO Keywords: Column experiments Retardation Alluvial sediment Organic compounds Chars Bacillus megaterium ABSTRACT This work investigates the transport behaviour of selected organophosphorus pesticides, OPPs (chlorpyrifos, CP; chlorpyrifos-methyl, CPM; chlorfenvinphos, CF) through Danube alluvial sediment in the presence of hydrochars and biochars. The investigated hydrochar, obtained at three different temperatures (180 ◦ C, 200 ◦ Cand 220 ◦ C), originated from sugar beet shreds (SBS) and Miscanthus×giganteus (MIS). Results are described by conventional advective-dispersive equation (ADE). Retardation coeffcients (R d ) for all OPPs were in the range 6.2–16. Biodegradation was 4.15 and 1.80 for CPM and CP, respectively, while for CF biodegradation did not occur. The addition of carbon rich materials increases retardation of all OPPs in the range from 4 to 18 times depending on the material. Column experiment results indicated that biodegradation of OPPs occurred (up to λ = 13). In order to confrm that biodegradation occurred in the column experiments, we isolated OPPs degrading microorganisms for the frst time from the alluvial sediment. A strain capable of degrading CP and CPM was isolated and identifed as Bacillus megaterium BD5 based on biochemical properties, MALDI TOF and 16S rRNA analysis (99.54% identity). The results demonstrate that hydrochars, biochars and isolated degrading bacteria may be effective agents for reducing the mobility of or removing OPPs in contaminated soils or sediments. 1. Introduction One of the most commonly used synthetic organic chemicals are pesticides with a total sales in 2011–2016 close to 400,000 t active ingredient (European Environmental Agency, 2018). Once in the soil, pesticides will be subjected to different physicochemical and biological processes that can be interrelated and will determine their fnal envi- ronmental fate. One of the class of pesticides widely applied in fruits and vegetables cultivation are organophosphorus pesticides (OPPs) (Fytia- nos et al., 2006; Li et al., 2018) due to their high performance and low cost (Zou et al., 2018; Aimer et al., 2019). They are used in crops, res- idential and commercial buildings, ornamental gardens and plants and also to control the presence of disease-carrying mosquitoes (Zou et al., 2018). Certain microorganisms including bacterial, fungal and algal strains can degrade OPPs. Such strains were mainly isolated from soils treated with OPPs and can be utilized to remove OPPs from the contaminated environments (Kumar et al., 2018). The main processes which control their fate and behaviour in the soil/sediment are sorption and biodegradation processes. Their mobility through the soil profle mainly depends on these two processes. Considering that microfora naturally occurs in sediment/soil and sorption characteristics of these media can play a key role in changing the chemical quality of groundwater (biological and physicochemical mechanisms), investigating the mechanism of pollutant transport is essential for understanding the risk of penetration of hazardous sub- stances into the drinking water sources. Groundwater sources located along the Danube are exposed to the strong infuence of this international river as well as the surrounding feld which together affect the quality of these waters. Regarding this, river bank fltration systems have traditionally been used to remove pathogens, bacteria, protozoa, natural organic matter, pesticides and suspended matter. One example of this water supply system is for the city of Novi Sad (R. Serbia) as the frst step in drinking water treatment. Different carbon rich materials could be used to protect groundwater * Corresponding author. E-mail address: snezana.maletic@dh.uns.ac.rs (S. Maleti´ c). Contents lists available at ScienceDirect Journal of Environmental Management journal homepage: http://www.elsevier.com/locate/jenvman https://doi.org/10.1016/j.jenvman.2020.111156 Received 2 April 2020; Received in revised form 27 July 2020; Accepted 29 July 2020