1. Recyclable materials: including waste paper, plastic, glass, metal and cloth. It should be noted that paper towels and toilet paper are not recyclable because of their strong water solubility.

2. Kitchen waste: also known as wet waste in Shanghai, including food wastes such as leftovers, bones, roots, leaves and peels.

3. harmful waste refers to wastes containing heavy metals, toxic substances or environmental hazards that are harmful to human health. Harmful waste includes batteries, light bulbs, mercury thermometers, paint buckets, expired drugs, expired cosmetics, etc. Generally, these wastes are recycled separately or landfilled.

4. Other wastes: refer to the refractory wastes such as brick and tile ceramics, muck, toilet waste paper, paper towels, etc., fruit shells, dust and food bags (boxes). Sanitary landfill can effectively reduce the pollution to groundwater, surface water, soil and air.