3. Integrated solid waste management practices environmental concept such as waste hierarchy, zero emission and cradle to grave concept and it is meant to achieve specific waste management objectives and goals. Based on those concepts, answer the followings; (a) List the hierarchy of integrated waste management. (b) Discuss the concept of zero emission and give 2 examples how this concept could be practiced in industries. (c) Describe the concept of "cradle-to-grave" in hazardous waste management and explain the importance of this concept in waste management. (d) Explain the difference between "recycling" and "recovery" in the hierarchy of waste management and which should be given higher priority. (25 Marks)