Reducing environmental noise pollution by improved control methods at power plants (case study: Mazandaran power plant).

Noise pollution is an important environmental problem and in comparison, to other pollutants, the control of environmental noise has been hampered by insufficient knowledge as well as a lack of criteria. Power Plant industries have worldwide substantial progress and noise pollution is one of the considerable environmental impacts of various processes of these industries. This cross-sectional research aimed to study the sound levels to control noise pollution at different sections of the Mazandaran Thermal Power Plant in Iran. Sound pressure level measurements and frequency analysis were performed using the net" method where the results were compared with ACGIH Threshold Limit Values. It was found that inside the factory most of the measuring stations have high sound levels in comparison to industrial standards of 85 dB(A). Office buildings have the lowest sound pressure among measured areas. As 43% of measured stations are located in danger areas. Also, environmental noise measurements around Mazandaran Power Plant as an industrial residential area have revealed that sound levels were not higher than the admissible standards in Iran. The electricity generator's fan and Feed Water Pump section produce high levels of noise; therefore, a silencer and an enclosure were designed respectively. The amount of noise reduction for the enclosure was 38.7 dB(A) while the values of insertion loss and for the silencer 63.9 dB(A) reduction has been achieved. [ABSTRACT FROM AUTHOR]