Question

Spent wash is a major pollution problem in which industry?

• A. Fertilizer industry
• B. Petroleum refinery
• C. Sugar industry
• D. Cement industry

Hint:

Logic Tip: "Wash" refers to the fermented liquid before distillation. "Spent wash" is what is left over (spent) after you boil the alcohol out of it. Since the alcohol comes from sugar cane molasses, it belongs to the Sugar industry.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Spent wash is the dark-colored, highly organic liquid waste (effluent) generated during the distillation process in distilleries, which are often integrated with sugar mills.
Step 2: Key Formula or Approach:
Identify the byproduct of molasses fermentation.
Step 3: Detailed Explanation:
In the sugar industry, molasses is fermented to produce alcohol. After the alcohol is distilled, the remaining liquid is called spent wash. It is one of the most difficult effluents to treat because it has a very high Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD), along with a deep brown color that prevents sunlight from entering water bodies.
Step 4: Final Answer:
Spent wash is a major problem in the sugar and distillery industry.