NOVELTY - Solid plastic materials comprise component A obtained from polymer derived from fossil sources; and component B consisting of water-soluble biopolymers (SBP), water-soluble sulfonated biopolymers (SSBP) obtained by sulfonation of SBP or residual biomass with concentrated sulfuric acid, fuming sulfuric acid, sulfur trioxide in liquid form or complexed to molecules with electron donor properties, and ligninsulfonates (LS) isolated from pulp and paper process effluents.    USE - Solid plastic material used for fabrication of packaging items, bags for collection and transport of wastes, mulch films and green house cover for use in agriculture, for fabrication of ion exchange resins and of membranes to be used in separation of gases or for selective transportation of ions in solution, and for use in which commercial polymers from fossil sources are used (claimed).    ADVANTAGE - The solid plastic materials has higher molecular weight, higher Young's modulus, higher tensile strength, lower cost, and higher environmental compatibility than existing plastic materials made entirely from polymers obtained from chemicals derived from fossil sources.    DETAILED DESCRIPTION - Solid plastic materials comprise components A and B. Component A is obtained from polymer derived from fossil sources made from aliphatic C chain and/or aromatic single and/or condensed rings, including reactive functional groups COOH, OH, NH2, CONH, or COOR; and component B consisting of water-soluble biopolymers (SBP), residual biomass (RBM) isolated from urban, agriculture, forest, agricultural-industrial, animal origin, or produced by human activity, or isolated from fossil sources including peat, lignite, and leonardite; water-soluble sulfonated biopolymers (SSBP) obtained by sulfonation of SBP or RBM with concentrated sulfuric acid, fuming sulfuric acid, sulfur trioxide in liquid form or complexed to molecules with electron donor properties, including but not limited to dioxane, dimethylsulfoxide, or ethers, and by sulfonation with sodium sulfite at pH of 2.5-11 at 25-220 degrees C under autogenous pressure, and isolated from reaction medium according to existing practices of organic chemistry; and ligninsulfonates (LS) isolated from pulp and paper process effluents.    R=alkyl or aryl.    INDEPENDENT CLAIMS are included for:    (1) fabrication of plastic material by mixing solution of components A and B in solvent; evaporating lower boiling solvents to obtain homogeneous solution; casting solution over metal surface; evaporating solvent to obtain film of desired thickness; and curing film at 105 degrees C until by immersion in water, film will not release water-soluble components and is detachable from evaporating film;    (2) water-insoluble films made from plastic materials and can be bent at 180 degrees without breaking;    (3) reduction of mineral content of SBP or SSBP by washing them in solid phase with hydrogen chloride and/or hydrogen fluoride;    (4) remediation of soil contaminated by organic substances and/or polluting metals by providing water solution containing mixture of biopolymers; contacting contaminated soil with biopolymers solution; and separating soil from solution, which contain organic substances and/or polluting metals, to obtain soil with reduce contaminant content;    (5) secondary treatment of washing solution recovered from soil remediation by acidifying recovered washing solution at pH of less than 4 to obtain precipitate; and drying and burning precipitated material to obtain metal concentrate for recycling;    (6) cleaning and/or lowering chemical oxygen demand of water contaminated by organic substances and/or polluting metals by providing mixture of biopolymers; adding mixture of biopolymers to contaminated water obtaining solution; and separating organic substances and/or polluting metals from solution through precipitation or filtration through micro-, ultra-, nano-porous and/or dialysis membranes to obtain retentate and permeate, in which permeate is clean water for further use and permeate is treated further; and drying and burning permeate to obtain metal concentrate for recycling;    (7) inhibition of mineralization of organic nitrogen in anaerobic fermentation of biomass by providing mixture of biopolymers; adding mixture of biopolymers to biomass in which biomass being water suspension; and subjecting biomass added with mixture of biopolymers into anaerobic fermentation to obtain digestate and biogas with reduced content of ammonia;    (8) use of mixture of biopolymers as supplement for animal feed by adding mixture of biopolymers to animal food to reduce mineralization of protein nitrogen contained in food when food is digested by animal, thus reducing methane and ammonia in animal dejection;    (9) use of mixture of biopolymers for enhancing leaf chlorophyll production, plant growth and productivity of food for humans and/or animals; and    (10) use of mixture of biopolymers as binding agents in manufacturing products.