Solid Waste Management MCQ with answer and solution

Concept

Carbon to Nitrogen (C/N) Ratio in Composting

Formula

N/A

Step-by-step solution

1. Analyze the statements regarding Carbon to Nitrogen (C/N) ratio in composting. 2. Recognize that a higher initial C/N ratio causes microorganisms to recycle limited nitrogen, resulting in higher conservation rather than lower. 3. Select Option C as the incorrect statement.

Explanation

The incorrect statement is that a higher initial C/N ratio leads to lower conservation of nitrogen in the finished compost. In simple terms, when the initial C/N ratio is high, carbon is high and nitrogen is scarce. Microorganisms must reuse and recycle the limited nitrogen repeatedly to break down the excess carbon, which actually results in maximum conservation of nitrogen. Conversely, a low initial C/N ratio means nitrogen is in excess, causing it to be lost to the air as ammonia gas.

Shortcut

To remember C/N ratio rules in composting, use these simple rules: - High C/N = High Conservation: When carbon is high, microbes recycle scarce nitrogen, maximizing nitrogen conservation. - Low C/N = Loss of Nitrogen: Excess nitrogen escapes into the air as ammonia gas. - Ideal C/N = 30 to 50: Optimal range for effective decomposition.

Common mistake

A common mistake is misinterpreting how nitrogen conservation works in composting and selecting Option A or B instead of Option C. Students often assume that a higher C/N ratio leads to greater nitrogen loss, whereas a higher C/N ratio actually forces microorganisms to recycle limited nitrogen, resulting in higher nitrogen conservation in the finished compost. Another frequent mistake is overlooking the "NOT correct" requirement in the question prompt.