Effect of operating parameters on leachate quantity and quality generated during hydrolysis of kitchen waste

Abstract

The global municipal solid waste (MSW) generation rate is 0.74 kg/capita/day, with an estimated annual waste generated to be 2.0 billion tonnes. It is poised to increase up to 3.4 billion tonnes by 2050 (Kaza et al., 2018). The composition of waste broadly comprises biodegradable and non-biodegradable fractions that depend on regional geography, economy, climate, lifestyle, social awareness and regulations. The biodegradable fraction majorly contributes between 40% and 50%, across the globe, dominated by kitchen waste, i.e., food, fruits and vegetables (Gerlagh et al., 1999; Futures, 2009; Yap and Nixon, 2015; Kaza et al., 2018). Fundamentally, these components are made up of carbohydrates, fats, proteins, lipids, inorganic salts and trace elements that led to a 40-70% bioenergy conversion efficiency (Ma et al., 2018). This high energy potential can be recovered by disintegrating waste into simpler compounds by anaerobic digestion (AD). The AD comprises hydrolysis, acidogenesis, acetogenesis and methanogenesis. It is considered as an effective technique to treat high moisture content waste (McKendry, 2002). Conventionally, the energy potential of organic waste has been used to obtain biogas and manure. The main component of biogas is methane (a GHG), posing a high risk to the environment. Also, the treatment of high moisture waste in thermal technologies reduces combustion efficiency drastically. Therefore, obtaining valuable products having a high commercial value such as ethanol, hydrogen, electricity and chemicals, broadens the waste to energy (WTE) concept. � Capital Publishing Company, New Delhi, India 2021. All rights reserved.