Multi-step system for treating selenium-containing wastewater

Patent metadata

Field	Value
Publication number	US-10745309-B2
Application number	US-201514969736-A
Country	US
Kind code	B2
Filing date	Dec 15, 2015
Priority date	Mar 11, 2015
Publication date	Aug 18, 2020
Grant date	Aug 18, 2020

Abstract

This specification describes a process and apparatus for treating water comprising selenium. A process is described having the steps of treating the wastewater influent using a biological reduction process to produce an intermediary stream and reducing the concentration of unconsumed constituents in the intermediary stream by means of filtration optionally with upstream coagulation or flocculation. When compared to the wastewater influent, the intermediary stream preferably has reduced concentration of the selenium species when compared to the wastewater influent. When compared to the intermediary stream, the effluent preferably has reduced concentration of one or more of the inorganic non-metallic constituents (such as nitrogen, phosphorous and sulphur), metallic constituents or organic constituents. An apparatus is described herein having a fixed film reactor configured to receive a wastewater influent, and a membrane filter configured to receive effluent from the fixed film reactor.

First claim

We claim:

1. A process for treating wastewater containing selenium comprising the steps of:
a) receiving an influent comprising metallic constituents and wastewater to be treated in a biological reactor;
b) adding nutrients comprising organic constituents to the influent and biologically treating said influent to produce a first intermediary wastewater containing reduced concentration of selenium species;
c) adding a chemical agent comprising a metal precipitant into said first intermediary wastewater to produce a second intermediary wastewater; and
d) mixing, flocculating, treating, and separating one or more of the organic, metallic or inorganic non-metallic constituents from the second intermediary stream in a downstream secondary treatment zone, wherein the downstream secondary treatment zone comprises a reactor, and introducing into the reactor activated sludge comprising a population of microorganisms responsible for a treatment of the organic constituents, the reactor comprising an immersed ultrafiltration membrane, and filtering said second intermediary wastewater to remove a precipitate or floc formed in step c) to produce effluent containing reduced concentrations of one or more of an unconsumed organic, metallic or inorganic non-metallic constituents.

2. An apparatus for treating water containing selenium and metallic constituents comprising:
a) an upstream fixed film reactor vessel or vessels configured to receive nutrients comprising organic constituents, and to precipitate and remove selenium from water; and
b) a downstream secondary treatment zone coupled with said upstream fixed film reactor vessel or vessels, the secondary treatment zone configured to precipitate and remove one or more of an organic, metallic or inorganic non-metallic constituents, wherein the downstream secondary treatment zone further comprises a mixer, a means to add a chemical agent comprising a metal precipitant, a flocculator, and a reactor configured to receive into the reactor an activated sludge comprising a population of microorganisms responsible for treatment of the organic constituents, the reactor comprising an immersed ultrafiltration unit.

3. The apparatus of claim 2 , wherein the reactor comprises a port for receiving into the reactor the activated sludge.

Assignees

• Gen Electric
• Bl Technologies Inc

Inventors

• Goldstein Jake
• Liu Minggang
• Owerdieck Carsten
• Fonseca Nelson
• Citulski Joel Alexander

Classifications

• Y02W10/10

  Biological treatment of water, waste water, or sewage · CPC title

• C02F3/2833

  using fluidized bed reactors · CPC title

• C02F1/004

  using large scale industrial sized filters · CPC title

• C02F3/2826

  using anaerobic filters · CPC title

• C02F1/52

  by flocculation or precipitation of suspended impurities {(C02F1/463 takes precedence)} · CPC title