Besides BOD, other tests that assess the organic content of wastewater are the ___ and __ tests.

• A. COD and TOC
• B. TSS and VSS
• C. pH and alkalinity
• D. Nitrates and phosphates

Answer: (A)

Testing organic content beyond BOD is typically done with chemical oxygen demand (COD) and total organic carbon (TOC). COD uses a chemical oxidant to break down organic matter and measures the amount of oxygen consumed, giving a practical estimate of the total organic load that can be oxidized—often in mg/L of oxygen. It responds quickly and includes both biodegradable and some nonbiodegradable organics, making it a useful complement to BOD, which reflects only what microorganisms can oxidize under specific conditions.

TOC directly measures the amount of carbon in organic compounds, reported as mg/L of carbon. This provides a straightforward gauge of organic matter present, independent of how easily it can be biologically degraded.

The other options don’t target organic content: TSS and VSS relate to solids, not the organic fraction; pH and alkalinity pertain to chemical properties and buffering capacity; nitrates and phosphates are inorganic nutrients rather than measures of organic material.