The aim of this work was to develop of novel cost-efficient nanocomposites synthesized by “green” methods with sufficient adsorption performance for heavy metal cations (Ni2+, Cd2+, Pb2+), phosphorous (phosphates), and sulfur (sulfates). Especially, the goal was to find the most suitable nanocomposite material and the most environmentally friendly and inexpensive method to produce this material in order to verify its possible use in real applications. Synthesis of nanocomposites was performed using microcrystalline cellulose (MCC), in PEG/NaOH solvent by a thermal-assisted method using layered double hydroxides (LDH) with various composition; iron oxide (III); manganese oxide (IV) and magnesium hydroxide (MH) as reinforcement. All of the materials had a structure of nanocomposites confirmed by TEM. The cellulose based material reinforced by magnesium hydroxide was selected for more detailed studies due to its appealing properties. Effects of time, temperature, and cellulose amount on its structure were investigated. Results of XRD, FTIR and EDS mapping showed that the materials composed of cellulose and magnesium hydroxide. And cellulose presented as a polymer matrix in the nanocomposites. TEM and SEM analyses showed an even distribution of MH nanostructures with various morphology in the produced materials. Each of the studied materials were tested as adsorbents with sufficient adsorption performance. Most of the materials demonstrated excellent uptake of nickel, cadmium, lead, phosphorous, and sulfur. The novel synthesis method used in this study is feasible, cost-efficient and environmentally friendly. Moreover, the studied materials showed excellent potential for the removal of both anionic and cationic pollutants from the wastewater.