NOVELTY - Process-I for recovering volatile and non-volatile products from a substrate-laden influent stream using microorganisms growing in a rotating bioreactor contactor, comprises (a) operating the rotating bioreactor as an aerobic, facultative or anaerobic reactor; (b) feeding the influent stream to the growth plates such that the growth plates are partially submerged within the stream for the growth of microorganisms to convert the substrate to volatile products and accumulate biomass; and (c) passing a stripping gas to the growth plates to harvest the volatile products as stripped gas.    USE - The method is useful for recovering volatile and non-volatile products from a substrate-laden influent stream, removing and harvesting nutrients from a nutrient-laden liquid influent stream and concentrating the chemical constituents of a stripping gas stream (all claimed).    ADVANTAGE - The method is capable of recovering the volatile and non-volatile products from the substrate-laden influent stream with less energy consumption, and economically concentrating and separating the nutrient laden biomass.    DETAILED DESCRIPTION - Process-I for recovering volatile and non-volatile products from a substrate-laden influent stream using microorganisms growing in a rotating bioreactor contactor, comprises (a) operating the rotating bioreactor as an aerobic, facultative or anaerobic reactor; (b) feeding the influent stream to the growth plates such that the growth plates are partially submerged within the stream for the growth of microorganisms to convert the substrate to volatile products and accumulate biomass; and (c) passing a stripping gas to the growth plates to harvest the volatile products as stripped gas, where the bioreactor comprises a vessel and a shaft mounted for rotation within the vessel about a shaft axis, multiple axially spaced-aparts, growth plates attached to the shaft, multiple plates having surfaces to which a fixed film of the microorganisms are attached, unit for rotating the shaft and plates about the axis. INDEPENDENT CLAIMS are included for:    (1) a process-II for removing and harvesting nutrients from a nutrient-laden liquid influent stream using autotrophic or phototrophic microorganisms growing in a rotating photobioreactor comprising (a1) shining light upon the microorganisms with an illumination unit, (b1) feeding the carbon source into the vessel, and (c1) feeding the influent stream to the growth plates such that the growth plates are partially submerged within the stream to remove nutrients in biomass from the influent stream using microorganisms, capturing the nutrients in biomass and then emitting oxygen gas and converting the influent stream to a nutrient-deficient effluent stream and (d1) removing a portion of the microorganisms from the surfaces of the growth plates using the harvesting unit; and    (2) a process-III for concentrating the chemical constituents of a stripping gas stream comprising (a2) conveying the stripped gas to an upstream side of a membrane disposed within a plenum, where the membrane has high permeability rate for water and a lower permeability rate for the stripping gas, stripping gas stream comprises stripping gas, water vapor, product volatile vapor and ammonia, (b2) applying a differential pressure between the upstream side of the membrane and an opposite downstream side of the membrane so that the water vapor passes through the membrane to the downstream side of the membrane as water vapor permeate within plenum gas, and the gas on the upstream side of the membrane becomes depleted of water vapor as plenum retentate gas, (c2) combining the plenum gas formed in step (b2) with the retentate gas that is deficient in condensate product to form a combined stripping gas.