The wood hydrothermal treatment is one of the plywood production’s stages, which
resulting in the production of wastewater containing such components as hemicelluloses, lignin
and wood extractive substances (HLES). It is necessary to improve the wastewater treatment
technology with the aim to enhance the yield of sludge from plywood wastewater for its effective
and rational recycling. In the present study, the optimal coagulation conditions for the HLES
removal have been found using the developed aluminium salt-based coagulant. The developed
composite coagulant is characterized by lower doses, a wide range of the work pH values, the
insensitivity against temperature changes and a higher coagulation efficacy compared with
traditional aluminium salts. The proposed treatment technology generates many tons of woodoriginated sludge – a biomass coagulate. It was found that the formed coagulate produced in the
process of wastewater treatment can increase the sorption ability of clay. The optimal content of
the dry coagulate in a clay sorbent does not exceed 0.11%. The sorption capacity of the developed
sorbent for water, rapeseed and silicone oil increases by 35%, 31% and 21%, respectively, relative
to the unmodified clay sorbent. The sorption efficiency of heavy metals from water solutions is
also increased by 10–12%. The thermal treatment of the modified clay sorbent at the high
temperature leads to an increase in its sorption capacity for oil products
