Study On The Purification Effect Of Negative Ions On PM_2.5 In Office Buildings

In recent years,frequent indoor air pollution problems of office buildings in China,which has a great impact on people’s health,work,and life.PM_2.5is one of the main indoor pollutants in office buildings,how to effectively remove PM_2.5 plays an important role in promoting people’s work,health,and even social and economic development.Negative ions can effectively reduce the indoor concentration of PM_2.5 and improve indoor air quality.However,the air temperature,humidity,and negative ions concentration can affect the process of negative ions on PM_2.5.In this paper,an environmental cabin is used to simulate an office building,by adding anion generators and artificial pollution sources,to study the effect of temperature,humidity,and negative ions concentration on the purification of PM_2.5by negative ions.And select a small office building in Guangzhou,by added anion generators,and measuring the varication of PM_2.5 concentrations,to verify the purification capacity of PM_2.5 by negative ions in the experiment.The main conclusions are as follows:（1）The purification capacity of PM_2.5 increases with the relative humidity,but decreases with the temperature without the anion generators.When adding anion generators,the purification capacity of PM_2.5 increases first and then decreases with the relative humidity,and it increases with the temperature.Under the same condition,PM_2.5 purification capacity is the highest when the temperature is between 28℃and 30℃;And it is the highest when the relative humidity is between 56%and 60%.（2）The effect of temperature on PM_2.5 purification capacity is more significant without the anion generators.The purification capacity of PM_2.5 is most affected by negative ions concentration,followed by temperature and relative humidity with anion generators.The purification efficiency of PM_2.5 is directly affected by the purification capacity.The purification efficiency of PM_2.5 is the highest at 25℃,60%,9×10⁶ ions/cm³,which is 0.58.（3）When the temperature remains stable,the concentrations of negative ions at the inside of environmental cabin increases with relative humidity.When the air humidity remains stable,the concentrations of negative ions at the inside of environmental cabin increases with the temperature.The utilization ratio of negative ions decreased with the negative ions concentrations,and it decreased with the relative humidity,however,it increased with the temperature.（4）According to the test,the measured value of PM_2.5 purification capacity at 20℃,70%,and 10⁶ ions/cm³ is 340μg/（m3·h）.And under the same working condition,the purification capacity of PM_2.5 calculated by the fitting curve is 376.26μg/（m3·h）,with an error rate of9.6%,which shows a good fitting.Finally,we can draw a conclusion:when we purify PM_2.5 by negative ions in office buildings,in order to achieve better purification effect:We can directly increase the concentration of negative ions;Or adjust the indoor temperature and humidity under the same conditions;And try to increase the indoor transmission distance of negative ions.