Solid Waste Management MCQ with answer and solution

Concept

The Hazardous Waste Rules list spent clay containing oil as a hazardous waste from petroleum refining.

Step-by-step solution

1. Recall the Schedule I process-wise list of the Hazardous Waste Rules. 2. Under petroleum refining, the listed wastes are oil sludge or emulsion, spent catalyst, slop oil, process organic residue and spent clay containing oil. 3. Spent clay containing oil matches this list, so the answer is D.

Explanation

In refineries, clay is used to treat and filter oil products. The used clay holds oil and toxic hydrocarbons, so it is a hazardous waste. The rules list it under petroleum refining.

Why the other options are wrong

A: Lead ash comes from lead smelting and battery recycling. B: Cyanide sludge comes from electroplating and heat treatment of metals. C: Tarry residues are mainly linked with coal tar distillation and coke ovens.

Shortcut

Refinery = oil, so pick the option that contains oil: spent clay containing oil.

Common mistake

Choosing tarry residues because tar looks like a petroleum product.