Recently, an innovative method for wastewater treatment and nutrient removal was developed by combining the sequence batch reactor and membrane bioreactor to overcome pollution caused by shipboard sewage. This system is a modified form of the activated sludge process and involves repeated cycles of mixing and aeration. In the present study, the bacterial diversity and dominant microbial community in this wastewater treatment system were studied using the MACROGEN next generation sequencing technique. A high diversity of bacteria was observed in anaerobic and aerobic bioreactors, with approximately 486 species. Microbial diversity and the presence of beneficial species are crucial for an effective biological shipboard wastewater treatment system. The Arcobacter genus was dominant in the anaerobic tank, which mainly contained Arcobacter lanthieri (8.24%), followed by Acinetobacter jahnsonii (5.81%). However, the dominant bacterial species in the aerobic bioreactor were Terrimonas lutea (7.24%) and Rubrivivax gelatinosus (4.95%).

Phytoplankton populations were examined at three sites in Lake Cheongpyeong, South Korea from March 2008 to December 2016, including measurement of phytoplankton communities and their dominant species, abundance and environmental factors. The annual average ranges of water temperature, dissolved oxygen and conductivity were 15.2-18.8℃ , 10.3-12.2 mg/L, 86-140 μS/cm, respectively, with similar values at all studied sites. The highest phytoplankton cell density was observed in spring and fall, and it subsequently decreased rapidly during heavy rainfall. Diatoms were dominant in spring (mainly Stephanodiscus hantzschii, Asterionella formosa) and fall (mainly Aulacoseira granulata), while greenalgae and cyanobacteria had high appearance in early-summer and summer, respectively, indicating that water temperature is the most important factor influencing their growth. Stephanodiscus hantzschii and Asterionella formosa frequently occurred at low water temperature (4.5-15.0℃ and 5.4-21.6℃ , respectively) while Aulacoseira granulata and Anabaena spp. were favored by high water temperature (8.6-28.4 and 14.9-26.2℃ , respectively) and phosphorus. Additionally, Fragilaria crotonensis occurred at low nutrient conditions. Rhodomonas spp. frequently appeared year-round.

작약 재배지에서 발생하는 잡초의 종류와 우점초종을 조사하여 잡초 방제의 기초 자료로 활용코자 경북의 의성, 영천 농가 작약 포장을 대상으로 조사한 결과는 다음과 같다. 1. 의성, 영천지역 작약재배지에 발생하는 초종수는 각각 14과 29종, 16과 30종의 잡초가 발생하였으며 두지역에서 총 17과 33종의 잡초가 발생하였다. 2. 잡초(雜草)의 분류학적(分類學的) 분포(分布)는 국화과 9종, 화본과 4종, 십자화과 3종, 마디풀과와 현삼과, 대극과가 각각 2종 등이었다. 3. 잡초의 생활사별 분류에 의한 발생비율은 일년생(一年生)이 19종(種)으로 57.6%, 월년생(越年生)이 8 종(種)으로 24.2%, 다년생(多年生)이 6 종(種)으로 18.2%이었다. 4. 형태적(形態的) 특성별(特性別) 잡초발생 초종은 화본과(禾本科) 4(12.1%), 광엽잡초(廣葉雜草) 25(84.8%), 사초과(莎草科) 1종(種)(3.1%)이었다. 5. 작약밭에 발생하는 주요 우점초종(優占草種)은 4월하순에는 냉이, 명아주, 쇠뜨기, 망초, 씀바귀, 6월하순에는 바랭이, 망초, 피, 쇠비름, 명아주, 8월하순에는 바랭이, 망초, 피, 쇠비름, 명아주 등의 순으로 나타났다.