전기화학적 처리를 통해 합성폐수 내의 질산성 질소, 인을 제거하는 새로운 폐수처리 공정 시스템 개발을 위한 연구를 수행하였다. 전류밀도에 따른 제거율은 전류밀도가 높아질수록 질산성 질소의 높은 제거효율을 얻었고, 전극 스위칭시간에 따른 N03-제거율은 스위칭 간격이 1 min일 때 높은 질산성 질소 제거효율을 얻었다. 전류밀도에 따른 총인 제거율은 전류밀도와 간격의 변화에 크게 영향을 받지 않으면서 90%이상 처리되는 것으로 나타났고, 스위칭시간(1 min간격)의 증가에 따른 총인 제거율은 증가 한 것으로 나타났다. 반면 COD의 경우는 전기화학적 처리를 통해서는 처리되지 않는 것으로 나타났으며 오히려 전극이 용출되면서 증가하는 결과를 얻었다. 또한, 전극의 소모율은 스위칭 간격이 짧을수록 적은 것으로 나타났다. 최종적으로 전기화학적 처리(전류밀도 50 mA/cm2, 스위칭 간격 1 min, 유량 540 mL/min)를 통해 질소 98.1%, 인 90% 이상의 제거 효율을 얻을 수 있었다.

For effective control of insect pest which can outbreak in a field during crop cultivation, various control agents such as eco-friendly agricultural materials (EFAM) including microbial control agents and chemical pesticides have been applied at fields and these control agents may be treated simultaneous or sequential in the same field to suppress diverse pests and diseases. The agents may influence each other and control efficacy may also differ from interactions. Therefore we need to test compatibility of microbial control agents with other agricultural agents. In this study, we investigated influence of pre-treated EFAMs, which are registered for whitefly control in greenhouse, on germination, mycelial growth and control efficacy of Isaria javanica isolate against sweet potato whitefly. The results showed that a mixture of paraffin oil+cinnamon oil among 4 EFAMs highly reduced germination (8.9±1.3%~24.5±0.9%) and mycelial growth (0.81±0.01cm~0cm) of I. javanica. To investigate the effects of the treatment interval between EFAMs and I. javanica on sweet potato whitefly control, four different EFAMs were pre-treated 0, 1, 4, and 7 days before applying I. javanica. Pre-treatment of four EFAMs inhibited insecticidal activity of I. javanica against sweet potato whitefly. Therefore when EFAMs and a mycopesticide using I. javanica spray simultaneous or sequential, application of EFAMs need more than 7 days interval after treatment of mycopesticide at field.

This experiment was carried out to determine the treatment interval on neem product for control of Bemisia tabaci on eggplant using eco-friendly agriculture. We have investigated the control effect of B. tabaci, growth characteristics of eggplant, economics according to neem product treatment interval on eggplant. The longer neem processing interval tended to decrease control effect on nymphs of B. tabaci. Control effect of nymph of B. tabaci according to treatment interval of 3 days, 5 days, 7 days, 10 days, and 15 days were 96.7%, 89.7%, 76.1%, 73.4%, and 51.0%, respectively. This result was the same tendency in adult of B. tabaci control effects on eggplant. Growth characteristics of eggplant according to neem the treatment interval of 3 days, 5 days, and 7 days, was less damaged on of B. tabaci. However, the 10 days, 15 days, and untreated of neem treatment intervals were badly damaged by B. tabaci. Therefore, neem treatment interval of 3~7 days for control of B. tabaci was high control effect. However, it is considered to be the most suitable to process every seven days considering the economics and so on. The results of economic analysis from income of 7 days neem treatment interval was the most high as 19.505 thousand won per 10a and the most economical treatment for control of B. tabaci.