**1. Introduction**

Rapid growth of the global population, permanently increasing life standards, and vast technological advancement are continually increasing the variety and amount of solid waste.

Generation of municipal solid waste, together with the high organic share present in solid waste and its often incorrect discarding, results in extensive ecological pollution, mainly based on the emission of gases that contribute to the greenhouse effect, such as methane (CH4) and carbon dioxide (CO2). Because of this environmental threat, municipal authorities are currently urged to implement techno-economic and political solutions of higher efficiency to manage the growing quantities of municipal solid waste [1].

The lion's share of municipal (mainly urban) solid waste consists of biodegradable matter, which plays a substantial role in greenhouse gas emissions in today's cities all around the globe. According to the present state of knowledge, integrated solid waste management is the strategy of choice to manage this issue; such strategies, however, require improvement in order to handle the growing organic fractions of municipal solid discards. If accomplished in a smart manner, this can on the one hand contribute to the aspired reduction of greenhouse gas emissions, and, on the other hand, even potentially generate economic benefits. Hence, systems for sustainable management of municipal solid waste are auspicious and attractive objects of study to assess current consumption behavior in different global regions and to protect the natural environment.

Generally, municipal solid waste gets disposed of in dumps and landfills as the most simple, convenient, inexpensive, and technologically less advanced method. Organic fractions as the major component of municipal solid waste undergo biodegradation under the anaerobic conditions prevailing in landfills, which consequently releases greenhouse gases as mentioned above [2].

Reduction or complete abolition of environmental contamination becomes increasingly important, which intensifies the global efforts dedicated to develop novel strategies for gradually reducing the quantities of the biodegradable municipal solid wastes in landfills. The process toward reduction of organic pollution involves (i) source separated collection of organic fraction of municipal solid waste, which undergo compost production, (ii) organic waste incineration for energy production, and (iii) mechanical/biological processing to get a compostable material [3].

This introduction chapter makes the reader familiar with the principles of municipal solid waste management, encompassing landfilling and recycling technologies; moreover, the composition of different types of municipal solid waste will be introduced. Based on this, the most feasible, promising, and realistic scenarios for municipal solid waste management are presented in order to provide

a solid scientific background of these processes implemented or in development, and the factors needed to assess the sustainability of these processes in a critical and straightforward fashion by using innovative sustainable assessment tools [4].
