The water in the lake has poor liquidity and the water flow is not easy to mix so the distribution of water quality is not uniform. The temperature of the lake varies with the depth of the water and directly affects the dissolved gas, especially the dissolved oxygen. In most cases, the dissolved gas content is different in each part of the lake, especially at different depths. The content of dissolved gas in one year depends on the change of water temperature. The dissolved oxygen content is the largest in winter and the smallest in summer. In small lakes, due to good heat conditions, strong photosynthesis is carried out in summer and lake water contains excess dissolved oxygen, so the surface oxygen content of small lakes is usually higher.

      Perennial pollutants enter the lake and form sludge deposited on the bottom of the lake. The organic matter in the sediment is decomposed by anaerobic microorganisms to produce hydrogen sulfide and methane due to lack of oxygen. The biological protoplasm (NO2-, NO3-, HPO42-, H2PO41-, NH4+) in the lake exist in the lake water and sediment. Moreover, due to the decomposition of organic matter at the bottom of the lake, the content of biological protoplasm in the water increases and the increase of nutrients causes serious eutrophication of water, which is easy to result in cyanobacteria bloom.

The schematic diagram of lake management

Features: the main purpose is to repair and construct the water ecosystem and restore the self-purification ability of the water. It has little influence on environmental and doesn’t produce secondary pollution or lead to the transfer of the pollutants. It can reduce the concentration of pollutants. It is convenient to construct and has a long long-lasting effect.