Wastewater treatment process including irradiation of primary solids

摘要

The present invention provides a method for treating wastewater in which the majority of solids and biological oxygen demand compounds are separated from the wastewater feed using a primary separation process, to produce a solids phase and a water phase. The solids phase is irradiated to reduce the level of pathogens such that it is safe to use as a soil substitute and/or additive so that the solids can thus be disposed of in an environmentally-friendly manner. In additional embodiments, the solids that have been disinfected by radiation are mixed with a suitable inert filler material to produce a soil substitute, fertilizer, compost, or other soil additive. The liquid phase is treated in a substantially smaller system than would be required for treating the full-strength wastewater that can include a suspended media biological regeneration reactor system. The liquid treatment system can include a high flux adsorbent material treatment system integrated with a low flux adsorbent material biological regeneration reactor.

主权项

1. A method for treating wastewater that contains solids, biological oxygen demand compounds and biologically refractory and/or bio-inhibitory compounds, the process comprising:
separating a majority of the solids and biological oxygen demand compounds from the wastewater feed using a primary separation process to provide a solids phase and a water phase including wastewater, the solids phase containing an initial level of pathogens; irradiating the solids phase to reduce the level of pathogens; mixing the wastewater comprising biologically refractory and/or bio-inhibitory compounds with adsorbent material in a mixing zone for a time sufficient for adsorption of biologically refractory and/or bio-inhibitory compounds from the wastewater onto the adsorbent material to produce a mixture of adsorbent-treated wastewater and adsorbent material having biologically refractory and/or bio-inhibitory compounds adsorbed thereon, wherein the adsorbent material is characterized by adsorptive capacity for adsorption of biologically refractory compounds and/or biologically inhibitory compounds, and capacity for microorganisms adhered to the adsorbent material, wherein the combined adsorbent material characteristics contribute to biological regeneration of the adsorbent material; separating and removing a major portion of the adsorbent-treated wastewater from the mixture of adsorbent-treated wastewater and adsorbent material having biologically refractory and/or bio-inhibitory compounds adsorbed thereon; passing the adsorbent material having biologically refractory and/or bio-inhibitory compounds adsorbed thereon and a minor portion of the adsorbent-treated wastewater to a biological regeneration reactor containing microorganisms; retaining the adsorbent material having contaminants adsorbed thereon and the minor portion of the treated wastewater in suspension in the biological regeneration reactor for a period of time that is sufficient to allow the microorganisms in the biological regeneration reactor to biologically act on at least a portion of the biologically refractory and/or bio-inhibitory compounds on the adsorbent material to produce biologically regenerated adsorbent material and a biologically treated water effluent; discharging the biologically treated water effluent from the biological regeneration reactor; and recycling biologically regenerated adsorbent material to the mixing zone.