Effectiveness of oscillatory gutter brushes in removing street sweeping waste Libardo V. Vanegas-Useche a,⇑ , Magd M. Abdel-Wahab b , Graham A. Parker c a Facultad de Ingeniería Mecánica, Universidad Tecnológica de Pereira, La Julita, Pereira, Risaralda, Colombia b Department of Mechanical Construction and Production, Faculty of Engineering, Ghent University, B-9000 Gent, Belgium c Mechanical and Aerospace Engineering (J5), Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, Surrey GU2 7XH, UK article info Article history: Received 4 March 2015 Accepted 12 May 2015 Available online 27 May 2015 Keywords: Road waste Street sweeping Debris collection Brushing effectiveness abstract In this paper, the novel concept of oscillatory gutter brushes of road sweepers is studied experimentally. Their effectiveness in removing different debris types is studied by means of a brushing test rig. The deb- ris types dealt with are medium-size gravel, small and fine particles, wet thin debris, and compacted deb- ris. The performance of two types of brushes, cutting and F128, under diverse operating conditions is investigated. The purpose of the tests is to ascertain whether brush oscillations superimposed onto brush rotation improve sweeping effectiveness. According to the results, brush oscillations seem to be useful for increasing brushing effectiveness in the case of bonded particles and wet thin debris, especially for bonded debris, but they seem to be of no value for other loosed debris. Also, appropriate values of brush penetration, sweeper speed, brush angle of attack, rotational speed, and frequency of brush speed oscil- lations, for the debris types studied are provided. Ó 2015 Elsevier Ltd. All rights reserved. 1. Introduction Litter on roads usually comprises leaves, small polluted parti- cles from vehicles, and different kinds of rubbish that is deposited by pedestrians or vehicle occupants. Furthermore, litter is a form of road pollution and, thus, is an important issue (Al-Khatib et al., 2009) that presents various problems (Carvalho et al., 2015; Hazra and Goel, 2009; Parthan et al., 2012). Therefore, due to pub- lic hygiene and for aesthetic purposes, it is important to sweep the streets on a regular basis. Road sweeping is commonly performed by lorry-type vehicles, which normally comprise a suction unit, a wide broom, and/or a gutter brush that sweeps the debris that lies in the gutter. Taking into account that about 80% of the debris is located in the gutter (Michielen and Parker, 2000; Peel et al., 2001), the efficient operation of the gutter brush is an important issue in street sweeping. In spite of the importance of street sweeping, the literature on this, in particular on road sweeping efficiency, is very limited. Some studies have focused on determining sweeping efficiency for removing contaminants from roadways (e.g., Walker and Wong, 1999); however, scientific papers on this are scarce (Amato et al., 2010). For example, Yuen et al. (2012) performed a study to quantify the sweeping efficiency in removing different road deposited sediments (RDS) grain size fractions from residen- tial and industrial roads; for this, the fine fraction (<63 mm) of all RDSs was analysed for more than 40 elements. The conclusion of this study was that street sweeping was effective in removing large organic debris and inorganic RDS but was not very effective in removing the fine fractions (<125 mm). Chang et al. (2005) study the effectiveness of road sweeping and washing for controlling ambient total suspended particles in Taiwan. In their research, a modified regenerative-air vacuum sweeper and a washer were used; the washer followed the sweeping pass. It was concluded that sweeping followed by washing may reduce up to 30% the emission potentials of total suspended particles. Keuken et al. (2010) investigated the efficiency of street sweeping and washing in reducing non-exhaust emissions in a street-canyon in Amsterdam. This study concluded that these measures were inef- fective for reducing non-exhaust emissions. Zhu et al. (2012) pre- sent a study on the effectiveness of control measures to reduce road dust emissions. Some attributes were analysed: sweeping procedures, anti-icing, shoulder improvement, road condition, trackout, and abrasive material from street segments. It was con- cluded that road sweeping was effective for controlling dust emis- sions from roads. Therefore, diverse and contradictory findings are reported in the literature regarding the efficiency of road sweeping from removing road pollutants. A discussion on this and further http://dx.doi.org/10.1016/j.wasman.2015.05.014 0956-053X/Ó 2015 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. Tel.: +57 6 3137124; fax: +57 6 3137362. E-mail addresses: lvanegas@utp.edu.co (L.V. Vanegas-Useche), magd.abdelwa- hab@ugent.be (M.M. Abdel-Wahab), g.parker@surrey.ac.uk (G.A. Parker). Waste Management 43 (2015) 28–36 Contents lists available at ScienceDirect Waste Management journal homepage: www.elsevier.com/locate/wasman