(US5120442-A)      Waste water contg. at least partially nonbiodegradable organic material is simultaneously chemically and biologically treated, by (a) inoculating a reservoir contg. water with microorganisms to aerobically degrade the contaminants, and (b) withdrawing a stream of waste water from the reservoir. Process then comprises (a) introducing withdrawn stream into a mixing zone and intimately mixing it with (i) compressed air or 02, so that dissolved 02 level rises to level to support aerobic metabolism, and (ii) oxidising agent so that locallised concn. of agent in the mixing zone rises such that chemical oxidn. of contaminants is effected; (d) returning treated waste water to the reservoir such that oxidising agent concn. is reduced by mixing with a larger amt. of waste water in the reservoir mixt. to a point where it is not toxic to microorganisms; and (e) continuously repeating (b)-(d) until concn. of contaminants falls to desired level.    ADVANTAGE -   30-40 % of gassing air is saved w.r.t. conventional one-stage process when material released is repurified to very low outlet valves.    (JP2777135-B2)      A process for simultaneous chemical and biological treatment of solid and liq. organic waste in which the biologically non-degradable prods. are rendered biodisposable by oxidn. and the biodisposable prods. are simultaneously biologically degraded, while maintaining (a) a high microorganism density in the reactor, (b) a high concn. of the prods. to be decomposed, which are present as a soln. or suspensionn in water; and (c) intensive aeration with air or air-oxygen mixts. with simultaneous addn. of an oxidising agent, while intensive mixing of the substrate with air or air/O2 is necessary with a short circuit time with the oxidising agent.. The effluent water from the process is pref. subjected to an active sludge treatment in the usual way except that aeration is carried out with CO2-contg. effluent air from the first stage treatment reactor, opt. after addn. of supplementary CO2.    USE/ADVANTAGE -   The process allows treatment of waters contg. high concns. of dissolved or suspended organic wastes which are biodegradable or which are biodisposable after oxidn.; minimum amts.. of water are involved, thus limiting the size of treatment plant required.