What is the effect of high BOD levels in wastewater?

High Biochemical Oxygen Demand (BOD) levels in wastewater are a critical indicator of organic matter concentration. When BOD levels are elevated, it means there is a significant amount of biodegradable material present in the water. As this organic matter decomposes, it is metabolized by microorganisms, which consume oxygen in the process.

This consumption of oxygen leads to a decrease in dissolved oxygen levels in receiving waters. When the oxygen levels drop, it can create anoxic or hypoxic conditions that are harmful to aquatic life, such as fish and other organisms that rely on dissolved oxygen to survive. Fish, in particular, may suffer from stress or even die if the oxygen levels fall below their tolerance thresholds.

In contrast, high BOD levels do not increase oxygen levels; rather, they indicate a higher concentration of pollutants that can lead to a decline in water quality. Therefore, the correct understanding of high BOD levels is that they ultimately result in decreased dissolved oxygen, which can adversely affect the ecosystem.