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International Research Journal of Engineering and Technology (IRJET)

e-ISSN: 2395-0056

Volume: 11 Issue: 01 | Jan 2024

p-ISSN: 2395-0072

www.irjet.net

Anaerobic Co-Digestion of Water Hyacinth : A Review Manali Jadhav1, Kiran Kangle2 1MTech Scholar, Department of Environmental Engineering, KIT’s College of Engineering (Autonomous), Kolhapur,

Maharashtra, India

2Assistant Professor, Department of Environmental Engineering, KIT’s College of Engineering (Autonomous),

Kolhapur, Maharashtra, India ---------------------------------------------------------------------***--------------------------------------------------------------------1.2 Anaerobic Digestion Abstract - Increased urbanization has led to significant waste management and energy challenges, instead of simply disposing of waste, waste recovery processes offer environmental benefits. Anaerobic digestion is a promising technology for recovery of energy from organic fraction of solid waste. Anaerobic digestion involves controlled microbial decomposition of organic matter in absence of oxygen, resulting in the production of biogas composed primarily of methane and carbon dioxide. The process consists of four steps, initially hydrolysis, acidogenesis, followed by acetogenesis and last is methanogenesis. Co-digestion, which involves digesting multiple types of waste simultaneously, is an effective approach. This study focuses on the use of water hyacinth, an invasive aquatic weed, for co-digestion. Since presence of water hyacinth in water body causes various aquatic environmental issues, its removal and proper disposal is required. By properly providing pretreatment and anaerobic co-digestion with another substrate, the disposal problem can be addressed and energy can be recovered from biogas produced. However, its main disadvantage is sometimes it requires pretreatment and while feeding to digester proper mixing ratio needs to be maintained.

Waste recovery is a waste management approach which aims to utilize the potential of waste and reduce the amount of matter that is ultimately discarded. In recent years, there has been a growing interest in converting biomass to methane through biological process. There are various technologies like incineration and refuse derived fuel (RDF) etc., have been developed for producing energy from solid wastes. Among these technologies, anaerobic digestion has become a promising method particularly for recovering energy from organic fraction of solid wastes. Anaerobic Digestion is an environment friendly technique that produces energy in the form of biogas, while residue which remained can be used as soil conditioner. Anaerobic digestion is a controlled process involving microbial decomposition of organic matter in absence of oxygen [3]. Anaerobic digestion (AD) consists of a number of complex biochemical reactions carried out by several types of microorganisms that survive in oxygen free conditions. This process produces biogas which is predominantly composed of methane (CH4) and carbon dioxide or (CO2) as major gases along with trace amounts of hydrogen sulfide (H2S), nitrogen (N2), hydrogen (H2) and water vapors. It’s a four-step process that involves the participation of different trophic groups at each stage. In the hydrolysis stage, organic macromolecules are broken down into monomers like sugars, fatty acids, and amino acids. These components are further broken down into VFAs (volatile fatty acids: shortchained fatty acids like acetate, butyrate, or propionate), organic acids, and alcohols, along with small amounts of hydrogen in the second acidogenesis stage. The largest fraction of H2 and acetate comes from the third step, the acetogenesis stage, in which bigger VFAs and other organic acids from the previous stage are converted into the two substances. Finally, in the methanogenesis stage, methane and carbon dioxide are produced [4]

Key Words: Anaerobic Co-digestion, Water hyacinth, Pretreatment, Substrate ratio, Inoculum

Introduction

1.1

General

Rapid uncontrolled and unmonitored urbanization has created serious problems regarding waste management and energy requirement. Effective management of waste generation and disposal is critical for environment sustainability, economic prosperity and social equality. The economic development of a country is mainly dependent upon the use of energy in industrial, transportation, domestic, and agricultural domains. The dependence on fossil fuel as primary energy source has led to global climate change, environment degradation and human health problems [1] The use of fossil fuels as the primary energy source has contributed to global climate change, environmental degradation and various human health problems. Therefore, alternative energy sources such as solar, wind, biomass and geothermal energy have gained attention as renewable and long-term solution [2]

Impact Factor value: 8.226

1.3 Co-digestion Co-digestion is the simultaneous digestion multiple types of waste in the same unit. The process offers several advantages, such as better digestibility, enhanced biogas production/methane yield arising from availability of additional nutrients, as well as a more efficient utilization of

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