RESEARCH ARTICLE Multifunctional diesel exhaust emission soot coated sponge for water treatment Vishvendra Pratap Singh 1 & Moolchand Sharma 1 & Rahul Vaish 1 Received: 11 October 2018 /Accepted: 18 December 2018 # Springer-Verlag GmbH Germany, part of Springer Nature 2019 Abstract We demonstrated that a pollutant and waste, diesel exhaust emission soot (DEES) can be used as an absorbent to remove oil and organic pollutants from wastewater. The diesel exhaust emission soot coated sponge (DEES sponge) was prepared using the dip- coating method. Prepared DEES sponge was found hydrophobic in nature as the contact angle between water drop and its surface was recorded to be 147°. The DEES sponge showed high absorption capacity with various oils, without any surface modifica- tions and pretreatments. Highest oil absorption capacity was found to be 39 g/g for engine oil. Excellent separation efficiency was recorded (max. 98.5% for engine oil). It shows promising recyclability having 95% efficiency even after 10 cycles. DEES sponge also demonstrated the capability to be used as an adsorbent due to its ability to absorb pollutants like methylene blue (MB), ciprofloxacin, and detergent from the water. It was able to adsorb 93% of the dye MB from its aqueous solution having concentration of 15 μM. Keywords Diesel exhaust emission soot . Oil-water filter . Adsorption Introduction Diesel-fuelled vehicles are foremost pollution contributor as they produce significant amounts of carbon monoxide, nitro- gen oxides, and small soot particles. Soot particles are harmful air pollutants that account for a large fraction of fine air par- ticulates in the atmosphere. There are some well-known neg- ative effects of these soot particles in ambient air such as contributing to global warming and disturbance in the climate via cloud nucleation processes. These particles have carciogenic potential as they got deposited in lungs when in- haled (Kawabata et al. 1988). Therefore, diesel exhaust emitted soot particles are hazardous waste and needed to be minimized (Muller et al. 2006). It can be done by developing more efficient diesel engines and exhaust after-treatment devices (Bose et al. 2010). Another fruitful approach to overcome waste soot parti- cles is to utilize it in a positive way by using properties of carbon which is a major constituent of the diesel soot particles. Largely varying properties due to the local bonding of consti- tuting carbon atoms make carbon a light and versatile material. Various carbon-based materials such as carbon nanotubes (CNTs), graphene, and candle soot have shown their potential in many fields (Ruoff et al. 1995; Spinks et al. 2002; Li 2012; Li et al. 2012). These materials have been successfully applied in superhydrophobic coatings, supercapacitor electrode material, lubricating additives, high absorbance material for solar collec- tors, and as an adsorbent for various organic pollutants in waste- water treatment (Kannan and Sundaram 2001; Pereira et al. 2003; Lau et al. 2003; Moreno-Castilla 2004; Sethi and Dhinojwala 2009; Deng et al. 2012; Cheng et al. 2013; Le et al. 2013; Caffrey and Gupta 2014; Yagub et al. 2014; Zhang et al. 2014; Fan et al. 2014; Huaiyuan et al. 2014; Karami et al. 2014; Dorri Moghadam et al. 2015; Wang et al. 2016; Gu et al. 2017). However, diesel exhaust emission soot has not been much explored yet for such applications. It has received less attention on finding its promising applications as compared to other members of carbon family like activated carbon, graphene, and candle soot. Vishvendra Pratap Singh and Moolchand Sharma contributed equally to this work. Responsible editor: Philippe Garrigues Electronic supplementary material The online version of this article (https://doi.org/10.1007/s11356-018-4045-0) contains supplementary material, which is available to authorized users. * Rahul Vaish rahul@iitmandi.ac.in 1 School of Engineering, Indian Institute of Technology Mandi, Mandi, H.P. 175005, India Environmental Science and Pollution Research https://doi.org/10.1007/s11356-018-4045-0