Abstract: In order to promote the biogas generation during anaerobic fermentation of straw in North China, an anaerobic fermentation experiment with mixed corn straw and pig excreta was conducted. The total concentration of fermenting materials was controlled as 10%, and the quantity of inoculum was 20%. The biogas production was measured under the conditions of temperature 25 ℃and 35 ℃, straw granularity <1 cm, 1-3 cm, and 5-10 cm, and mass ratio of corn straw to pig excreta 1:1, 1.5:1, 2:1. The results showed that the daily and cumulative biogas productions were the highest under conditions of temperature 35 ℃, straw granularity 1-3 cm, and mass ratio of corn straw to pig excreta 1.5:1. These conditions could be used as the recommended parameters of anaerobic fermentation of mixed corn straw and pig excreta in North China countryside.

Key words: Organicall modified clay, Prorocentrum donghaiense, Red tide