Page 20 - mobile Workbook-chapter 2

The above compounds serve as a substrate for a wide range of micro - and macroorganisms

important in composting and other biological processing. All of these organic components can be
biologically converted into gases and relatively stable organic and inorganic solids [6].

The biodegradability of the organic fraction of MSW can be determined via simple laboratory

tests for volatile solids and lignin content. The biodegradability factor can be calculated by the
equation:

BF = 0.83 - 0.028LC [1]

where BF represents the biodegradable fraction expressed on a volatile solids basis and LC
the lignin content of the volatile solids expressed as a percent of dry weight.

Wastes with high lignin contents such as newspaper and cardboard tend to be of low
biodegradability. Materials with a low lignin content, for example food wastes and grass clippings,

tend to have a high biodegradability.

2.11 Toxic/hazardous waste

Increased technological complexity and population densities have resulted in the identification

of a new type of pollutant, commonly called a hazardous substance.

The term hazardous substance or hazardous waste is difficult to define, and yet a clear

definition is necessary if specialized disposal standards are to be applied to such materials.

Simply defined, a hazardous waste is a waste with properties that make it dangerous or capable
of having a harmful effect on human health or the environment. According to G. Tchobanoglous,

the basic federal categories for hazardous waste determination are:
• Ignitability

• Corrosivity
• Reactivity

• Toxicity

The US Regulation
Title 40: Protection of Environment in subpart CC - Air Emission Standards for Tanks and

Containers. Part 261 - Identification and listing of hazardous waste. More
The regulation in VN

36/2015/TT-BTNMT: Về quản lý chất thải nguy hại. Ngày hiệu lực 30.06.2015. More

2.12 Transformation processes

Both chemical and biological transformation processes typically involve change in phase (e.g.,
solid to gas) while physical transformation do not. Typically waste transformations are used:

• to improve the efficiency of solid waste management systems
• to recover reusable and recyclable materials

• to recover conversion products and energy

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