The problem of surface waters pollution with heavy metals and their accumulation in the sediments of wastewaters that are formed on the cleaning installations of municipal enterprises is the top priority in the area of environmental protection and resource saving. The absence of wastewaters sediments disposal and increase in their quantity in the active sludge banks lead to the expropriation of the new land sites for storage areas, pollution of underground waters and air while wastewaters sediments can be used as a secondary raw material after the additional processing aimed at reducing the toxic influence of heavy metals. The author of article proposes the methods for obtaining biosorbent from wastewaters sediments using thermal pyrolysis and the methodology of its specific surface area study. For this purpose, the wastewaters sediments, after the previous processing by dehydration and grinding, are subjected to pyrolysis in the hermetically sealed container, which is isolated from air and connected hydraulically with pyrolysis process control block. In the process of pyrolysis, the wastewaters sediments are transformed into metals oxides which can be used as biosorbents. The biosorbent specific surface area was studied using the low temperature nitrogen absorption method