Generally, waste could be liquid or solid waste, and both could be hazardous. Liquid and solid waste types can also be grouped into organic, reusable, and recyclable waste.

Let us see some details below:

• Liquid type:

Waste can come in the non-solid form. Some solid waste can also be converted to a liquid waste form for disposal. It includes point source and non-point source discharges such as stormwater and wastewater. Examples of liquid waste include wash water from homes, liquids used for cleaning in industries, and waste detergents.

• Solid type:

Solid waste mostly is any garbage, refuse or rubbish that we make in our homes and other places. These include old car tires, old newspapers, broken furniture, and even food waste. 

• Hazardous type:

Hazardous or harmful waste are those that potentially threaten public health or the environment. Such waste could be inflammable (can easily catch fire), reactive (can explode), corrosive (can eat through metal), or toxic (poisonous to humans and animals). In many countries, it is required by law to involve the appropriate authority to supervise the disposal of such hazardous waste. Examples include fire extinguishers, old propane tanks, pesticides, mercury-containing equipment (e.g. thermostats) and lamps (e.g. fluorescent bulbs), and batteries.

• Organic type:

Organic waste comes from plants or animal sources. Commonly, they include food waste, fruit peels, vegetable peels, flower trimmings, and even dog poop can be classified as organic waste. They are biodegradable (this means they are easily broken down by other organisms over time and turned into manure). Many people turn their organic waste into compost and use it in their gardens.

• Recyclable type:

Recycling is processing used materials (waste) into new, useful products. It is done to reduce the use of raw materials that would have been used to produce new things. Waste that can be potentially recycled is termed Recyclable waste. Aluminum products like soda, milk, and tomato cans, plastics (grocery shopping bags, plastic bottles), glass products (like wine and beer bottles, broken glass), paper products (used envelopes, newspapers and magazines, cardboard boxes) can be recycled and fall into this category.