Study On Effects Of Pulsed Electric Field On Release Of Negative Ions Of Some Araceae Species

Negative air ion, which is well-known as "air vitamin" and very beneficial to human health, can regulate physiological function and promote metabolism. In recent years, air quality has drawn increasing attention. And as an important indicator for the measurement of air quality, air anion concentration is not optimistic. Therefore, the study on how to improve the anion concentration in air is critical.In this study,20 common Araceae species, selected from 11 common indoor ornamental plants, were chosen to determine and compared from each other about their NAI concentration in the absence of stimulation (natural situation) and upon different electric stimulation through the soil. The generation of highest NAI concentration in Araceae species and their corresponding parameters on pulsed electric field was survey and optimized. What is more, multiplier effect of Araceae species on negative ions was evaluated. The main results are as follows:1. The NAI concentration released of Araceae species in natural conditions was very low. The mean value in daytime is 50 ion/cm3, the highest, for Philodendron ’Xanadu’, and 10 ion/cm3, the lowest, for Philodendron martianum. The range of day mean values of NAI concentration released by control groups is 9-34 ion/cm3. Compared to the NAI concentration of control group, that of Philodendron ’Xanadu’ increased 47.1% in the natural conditions, only 16/cm3 for absulate value. There is no increase for Philodendron selloum and Dieffenbachia amoena ’Camilla’ between control group and treatment group.2.15 kV high-voltage pulse was imposed on the 20 species studied through soil by high-voltage pulse generator. There is no significant difference for 17 species between electrostimulation plants and non-electrostimulation plants. NAI concentration upon electric stimulation through the soil considerably increased for three species, which are Monstera deliciosa, Aglaonema commutatum’SanRemo’and Alocasia × amazonica. The NAI concentration in Monstera deliciosa increased from 36 ion/cm3 in the absence of electrostimulation to 262,084 ion/cm3 on electrostimulation. The NAI concentration in Aglaonema commutatum’SanRemo’ increased from 34 ion/cm3 in the absence of electrostimulation to 207,157 ion/cm3 on electrostimulation. The NAI concentration in Alocasia x amazonica increase from 36 ion/cm3 in the absence of electrostimulation to 114,403 ion/cm3 on electrostimulation.3. Three factors, namely pulse voltage, frequence and pulse width, were selected for orthogonal design to optimize the parameters of electrostimulation to generate highest NAI concentration. Aglaonema commutatum ’SanRemo’ generated highest NAI concentration after optimization and attained to 771,210 ion/cm3, which was 5.7 times more than that before optimization. Aglaonema commutatum ’SanRemo’ could generate high level of NAI concentration continuously for 10 days without plant individual damage. Monstera deliciosa attained to 700,155 ion/cm3, which was 1.7 times more than that before optimization. Monstera deliciosa could generate high level of NAI concentration continously for 6 days. Alocasia x amazonica attained to 233,460 ion/cm3, which was 0.1 times more than that before optimization.Alocasia x amazonica could generate high level of NAI concentration continously for 4 days.