Non-thermal plasma has been widely investigated to apply to environmental protection. The effectiveness of electrical discharge technology on decomposition and transformation of toxic gases has been widely studied, while its influence on the toxic substances in fly ash is not clear. In this paper, the surface chemical transformation of fly ash from electrostatic procipitators has been studied by surface pulse discharge. A surface mechanical change and a destruction of powder particles were visible after discharging. This indicates that the pulse discharge causes an effective desturction of the fly ash powder and its particles. The composition analysis showed that volatile organic compound (VOC) content in sampies decreases after discharging. A positive pulse discharge showed a higher decrease in VOC content than that of a negative one did. We concluded that by using the surface pulse discharge, especially in the case of positive pulse discharge, the non-thermal plasma is also effective on decomposition and transformation of toxic substances in fly ash, which reaches a 51% VOC decomposition effectiveness.

In this paper, three kinds of annealing methods with different cooling rates are used to prepare low-density polyethylene (LDPE) samples with different microstructure in crystal-linity. The effects of crystallinity on space charge properties are investigated. It was found that homo-charges are easier to accumulate inhigh rate cooling sample and hetero-charges are easier to accumulate near cathode in low rate cooling sample. It was also found that charge movement and neutralization oceurs with the increases of the applied field and the voltage appliying duration. Based on these results, the influence of crystallinity on spae charge accumulation is emphasized.

In order to study the inactivation effects of electrostatic field of electret films on Bacillus subtilis, a plane-plane electrode system was used to simulate the electrie field of the electret films and the viability of B. sublilis affected by electrostatic field for different applying durations was investigated. It was found that the survival ratio of B. subtilis can be considerably affected by the field and duration. It was also found that the viability of bacillus decreases with the increase of the duration. In addition, the comparative survival ratio (CSR) of B. subtilis decreases to 35% even during a short duration as the applied field reaches an enough high value of more than 15kV/cm. These indieated that the uniform field inactivated the viability of B. subilis availability. Based on the inaction effect of the applied field on the B subtilis, the effectiveness of chared polypropylene films on the inactivation of B. subtilis was measured and discussed.

In a streamer dominated pulse corona the energetic electrons can interact with the gas molecules and produce radicals. Emission of second positive band (SPB) of the nitrogen, which was considered to orrespond to local yield of N radical, was monitored in this study for analyzing Nradical effect on removal of itrogen oxidex (NOx) from exhaust gases. It was found that the length of high luminous region (HLR) is related to energy efficiency of NOx removal. It was also testified that total emission intensity of SPB is linearly proportional with NOx removal in No/N2 mixture gas. Analysis of experimental data shows that the NOx removal energy efficiency is smaller when pulse width is longer. The energy efficiency also decreases with the increase of injected power and length of HLR, respectively. It was assumed that the local concentrated production of N radical in HLR is not effectively used for NO removal in the condition of low initial NOx concentration. It is concluded that the luminescence analysis provides a good method to understand NOx removal process in pulse discharge co-rona.

In this paper, a needle-plane electrode system and polypropylene (PP) films were used to study the DC corona charging of polymers. It was found that the charges injected into the PP films sometimes show different polarity to the applied DC voltage, called polarity reversal charging, which may results in invalidation charging. The pulsed electro-acoustic (PEA) space charge measurement showed that charges of different polarities have been injected into the PP films' bulk, simultaneously. From these results, a mechanism of two charging processes of high-field inection and return-stroke injection has been introduced here. We presumed that the return-stroke injection can be boosted with the increase of corona voltages and thus reduces the net charge as well as even change the polarity of charges injected.