Humification characteristics of products from hydrothermal treatment of aquatic wastes

Taking aquatic product processing waste as the main experimental object, the effects of reaction temperature, reaction time and inorganic weak acid on the formation and transformation of humus in hydrothermal process were investigated. By analyzing the pH value of hydrothermal products, the content of organic matter and humus, humification rate, and infrared spectrum analysis and verification, the formation mechanism of humus can be inferred. The results show that hydrothermal treatment can promote the formation of humus to a certain extent. Under the working conditions of 195 degrees C and 80min, the humus content of aquatic wastes reaches 78.1% and the humification rate reaches 0.35. In addition, within a certain treatment intensity, the hydrothermal humification intensity will increase with the increase of reaction time and temperature. Under the same working conditions mentioned above, adding a certain amount of inorganic acid for hydrothermal treatment, the humus content is slightly higher than that of the group without acid. The humification rate reaches 0.45, which is 0.3 times higher than that of the group without acid. It shows that hydrothermal treatment can promote the formation of humus to a certain extent. Additionally, the humic rate of acid-hydrothermal treatment group (acid-HT) is obviously better than that of hydrothermal treatment group (HT). Compared with prolonging the reaction time, the increase of temperature has a more obvious effect on the increase of humification rate.