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The parasitic dinoflagellates of the genus Hematodinium have been considered one of the most important emerging pathogens for a broad range of marine crustaceans around the world. In China, frequent outbreaks of Hematodinium infections have caused serious economic losses for local farmers since 2004. Wild crabs were recently indicated to play a vital role in the transmission and spreading of the Hematodinium disease in polyculture pond systems. Based on PCR amplification and histopathological examination, we demonstrated that H. perezi can naturally infect a wild crab species, Hemigrapsus takanoi, which were collected from the waterways located on the coast of Rizhao or Weifang, Shandong Peninsula, China. According to the sequence similarity analysis and phylogenetic analysis, the Hematodinium isolates were identified as H. perezi and belonged to genotype II. The prevalence of H. perezi ranged from 3.3% to 5.7% in H. takanoi originating from Rizhao (n = 165 wild crabs) and from 0.9% to 20.0% in that originating from Weifang (n = 1386 wild crabs), respectively. To our knowledge, H. takanoi is, for the first time, reported as a new host for Hematodinium. Given the wide distribution of H. takanoi on the coasts along the Shandong Peninsula and the relative high prevalence of infection we monitored in our study, we speculate that H. takanoi contributes to the introducing and spreading parasitic Hematodinium between ponds via waterways in a poly‐culturing system. Findings in this study broaden the host range of this parasite and expand the scope of our surveillance for Hematodinium disease in China. [ABSTRACT FROM AUTHOR]

ECOSUNIDE is a new activated sludge process based on the sludge concentration optimization theory. With it, we carried out a high sludge concentration by changing influent mode and distributing carbon source in a reasonable way, which can improve the ecological superiority of nitrification and denitrification for the growth of phosphorous accumulating organisms (PAOs) and nitrifiers and raised the nutrient removal efficiency of municipal sewage treatment plants. In 2007, we adopted this technique in Linyi Sewage Treatment Plant in Shandong Province, China. After the reconstruction, we achieved the high efficiency of nutrient removal with low investment under the dynamic load of the secondary sewage treatment plant. The effluent water qualities meet the class I-A criteria specified in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918 - 2002) and the rest effluent indexes meet the class I -B criteria. Besides, we have above 20% operating cost cut by stopping the internal reflux without power charge increased and any new pool structures built. [ABSTRACT FROM AUTHOR]