Which of the following is a common method for achieving emission control in fossil fuel boilers?

Utilizing scrubbers and filters is a well-recognized method for controlling emissions in fossil fuel boilers. Scrubbers are designed to remove harmful pollutants from flue gases before they are released into the atmosphere. They work by introducing a reactant, typically a liquid, that interacts with the gas stream to capture or neutralize pollutants such as sulfur dioxide (SO2) and particulate matter. Filters further aid in trapping particulates, ensuring that the exhaust from the boiler meets environmental regulations and minimizes air pollution.

In contrast, while installing insulation may improve energy efficiency by reducing heat loss, it does not directly address emissions. Reducing the water supply may affect the boiler's operation and efficiency but would not lead to lower emissions. Increasing the fuel input could potentially raise the emissions, as more fuel combustion typically results in greater output of pollutants if not accompanied by proper emissions control technologies. Therefore, the use of scrubbers and filters stands out as the primary and effective approach for managing emissions from fossil fuel boilers.