Water treatment structures may have at least a first geotextile fabric layer; a second geotextile fabric layer; a third geotextile fabric layer; a first filler layer with plastic particles, arranged between the first and second geotextile fabric layers; and a second filler layer with plastic particles, arranged between the second and third geotextile fabric layers, wherein the geotextile fabric layers and the filler layers are within a housing, and wherein the structure is configured such that contaminated water proceeds sequentially through the first geotextile fabric layer, the first filler layer, the second geotextile fabric layer, the second filler layer, and the third geotextile fabric layer. Methods of treating wastewater may involve passing wastewater, after optional oxygenating and pre-filtering, through such alternating layers of geotextile, preferably nonwoven, and polymer particles.

A cord for supporting a biofilm has a plurality of yarns. At least one of the yarns comprises a plurality of hollow fiber gas transfer membranes. At least one of the yarns extends along the length of the cord generally in the shape of a spiral. Optionally, one or more of the yarns may comprise one or more reinforcing filaments. In some examples, a reinforcing yarn is wrapped around a core. A module may be made by potting a plurality of the cords in at least one header. A reactor may be made and operated by placing the module in a tank fed with water to be treated and supplying a gas to the module. In use, a biofilm covers the cords to form a membrane biofilm assembly.

Water treatment structures may have at least a first geotextile fabric layer; a second geotextile fabric layer; a third geotextile fabric layer; a first filler layer with plastic particles, arranged between the first and second geotextile fabric layers; and a second filler layer with plastic particles, arranged between the second and third geotextile fabric layers, wherein the geotextile fabric layers and the filler layers are within a housing, and wherein the structure is configured such that contaminated water proceeds sequentially through the first geotextile fabric layer, the first filler layer, the second geotextile fabric layer, the second filler layer, and the third geotextile fabric layer. Methods of treating wastewater may involve passing wastewater, after optional oxygenating and pre-filtering, through such alternating layers of geotextile, preferably nonwoven, and polymer particles.

Disclosed are floating micro-aeration unit (FMU) devices, systems and methods for biological sulfide removal from water/wastewater bodies and streams. In some aspects, a system includes a manifold structure including one or more opening to flow air out of an interior of the manifold structure; one or more support structures connected to the manifold structure, in which the one or more support structures are floatable on a surface of a fluid that includes water or a wastewater; and an air source that flows air to the manifold structure, such that the manifold structure supplies the air containing a predetermined amount of oxygen (e.g., less than 0.1 mg/L of oxygen) to oxidize sulfide of the fluid.

A system for thermally bonding nonwoven fibers of assemblages of nonwoven fibers loosely held together may include a processing duct including an inlet end, an outlet end, and an intermediate portion extending between the inlet end and the outlet end. The system also may include one or more heat inlets located in the intermediate portion and configured to facilitate introduction of heat and air flow into the intermediate portion. The system further may include an inlet air feed at the inlet end and configured to separate the assemblages upon entry into the inlet end and propel the assemblages into the intermediate portion. The system also may include one or more heating devices configured to heat the assemblages as the assemblages are conveyed toward the outlet end to form processed assemblages, each of the processed assemblages including at least some nonwoven fibers adhered to one another.

This specification describes a membrane aerated biofilm media and reactor (MABR) having a discontinuous layer of a porous material applied to the outer surface of a gas-transfer membrane. The porous material may have a void fraction of 50% or more. The porous material may have a thickness of up to about 500 microns and a pattern on the same order of magnitude as its thickness. The media may be used to carry on a deammonification reaction. In use, ammonia oxidizing bacteria (AOB) and annamox bacteria grown in or on the media, with the annamox bacteria located primarily in the porous material. The supply of oxygen through the gas-transfer membrane is limited to suppress the growth of nitrite oxidizing bacteria (NOB). Excess biofilm is removed, for example by coarse bubble scouring. The media may be placed in an anoxic zone of an activated sludge plant, which may be upstream of an aerobic zone.

A cord for supporting a biofilm has a plurality of yarns. At least one of the yarns comprises a plurality of hollow fiber gas transfer membranes. At least one of the yarns extends along the length of the cord generally in the shape of a spiral. Optionally, one or more of the yarns may comprise one or more reinforcing filaments. In some examples, a reinforcing yarn is wrapped around a core. A module may be made by potting a plurality of the cords in at least one header. A reactor may be made and operated by placing the module in a tank fed with water to be treated and supplying a gas to the module. In use, a biofilm covers the cords to form a membrane biofilm assembly.

Water treatment structures may have at least a first geotextile fabric layer; a second geotextile fabric layer; a third geotextile fabric layer; a first filler layer with plastic particles, arranged between the first and second geotextile fabric layers; and a second filler layer with plastic particles, arranged between the second and third geotextile fabric layers, wherein the geotextile fabric layers and the filler layers are within a housing, and wherein the structure is configured such that contaminated water proceeds sequentially through the first geotextile fabric layer, the first filler layer, the second geotextile fabric layer, the second filler layer, and the third geotextile fabric layer. Methods of treating wastewater may involve passing wastewater, after optional oxygenating and pre-filtering, through such alternating layers of geotextile, preferably nonwoven, and polymer particles.

Water treatment structures may have at least a first geotextile fabric layer; a second geotextile fabric layer; a third geotextile fabric layer; a first filler layer with plastic particles, arranged between the first and second geotextile fabric layers; and a second filler layer with plastic particles, arranged between the second and third geotextile fabric layers, wherein the geotextile fabric layers and the filler layers are within a housing, and wherein the structure is configured such that contaminated water proceeds sequentially through the first geotextile fabric layer, the first filler layer, the second geotextile fabric layer, the second filler layer, and the third geotextile fabric layer. Methods of treating wastewater may involve passing wastewater, after optional oxygenating and pre-filtering, through such alternating layers of geotextile, preferably nonwoven, and polymer particles.

Disclosed are floating micro-aeration unit (FMU) devices, systems and methods for biological sulfide removal from water/wastewater bodies and streams. In some aspects, a system includes a manifold structure including one or more opening to flow air out of an interior of the manifold structure; one or more support structures connected to the manifold structure, in which the one or more support structures are floatable on a surface of a fluid that includes water or a wastewater; and an air source that flows air to the manifold structure, such that the manifold structure supplies the air containing a predetermined amount of oxygen (e.g., less than 0.1 mg/L of oxygen) to oxidize sulfide of the fluid.