Systems and methods are provided for nitrogen gas sparging assisted biological treatment of water. In one example, a denitrification system may include a media-packed column or bed through which nitrogen gas is sparged to remove dissolved oxygen from water. In some examples, an external carbon source and electron donor may be added to the media-packed column or bed to facilitate biological removal of the nitrate and/or other contaminants from the water. In this way, by relying on the sparged nitrogen gas to remove the dissolved oxygen, less of the external carbon source and electron donor may be employed as compared to denitrification systems not assisted by nitrogen gas sparging.

The present invention relates to systems and methods for removing and recovering precious metals, such as platinum-group metals (PGMs), including palladium, from wastewater and waste streams. The invention also relates to systems and methods for recycling the recovered precious metals for catalytic applications.

Methods of delivering microorganisms loaded onto an inorganic porous medium. Methods of treating wastewater to increase effluent and biosolids quality. Methods of reducing ammonia and denitrifying wastewater effluent. Methods of reducing phosphorous concentration in wastewater effluent. Composition of biosolids derived from wastewater treatment. Wastewater treatment assemblage for increasing wastewater effluent and biosolids quality.

Culture systems and methods of using same. The systems include a housing defining an inner space. The inner space includes a headspace and at least a portion of a reservoir. A surface for immobilizing cells is moveable between the headspace and the reservoir. The systems can be used for coculturing methanotrophs and phototrophs for processing biogas and wastewater, particularly from anaerobic digesters.

Provided are: a water treatment method that includes at least a denitrification step for denitrifying water to be treated with a denitrifying bacterium in the presence of a hydrogen donor, wherein the denitrification activity of the denitrifying bacterium can be maintained at a high level and thus the treatment speed can be increased; and a water treatment apparatus. The water treatment method includes at least a denitrification step for passing water to be treated through a biological treatment tank and denitrifying the same with a heterotrophic denitrifying bacterium in the presence of a hydrogen donor, wherein: molybdenum is added to the water to be treated to give a concentration of 0.01-1.0 mgMo/gN; a carrier is added to the biological treatment tank; and the nitrogen load to the carrier is controlled to 1.6 kgN/(m.sup.3-carrier.Math.d) or greater.

A biological reactor system treats concentrated contaminated water with a combination of upflow and downflow bioreactors that are downstream from a reverse osmosis or other concentrator. The system may have a fail safe configuration where flush water may be introduced to the reactors in the event of a power failure or when taking the reactors offline. Many reverse osmosis systems introduce antiscalant treatments upstream so that the reverse osmosis filters do not scale. However, such treatments result in superconcentrated conditions of the antiscalants in the contaminated water processed by the bioreactors. A flushing system may deconcentrate the bioreactors to prevent the antiscalants from precipitating and fouling the bioreactors.

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 syntrophic enrichment for enhanced digestion (SEED) system is presented, in which a retrofit addition to existing anaerobic digestion infrastructure provides improved digestion process rate and biogas quality. The system provides optimal niche environments for accelerating fermentative, syntrophic and methanogenic metabolisms to increase digestion system loading rates and enhance main digester microbiome. Prescribed media formulations, reactor integrations, and operational methods using various fixed and loose media enhance global digestion system performance. The retrofitted system enables existing plants to transition from an outdated solids-management model to one of valorized biomethane production.

A bio-enhanced deodorization equipment includes a main body and a filler container in the main body. The filler container includes a wall and at least three perforated separator plates vertically arranged in the filler container. A plurality of spaces are formed by the at least three perforated separator plates, and a microbial filler and a carrier filler are accommodated in the spaces in an alternate manner.

In one embodiment, a system includes first anoxic moving bed biofilm reactor (MBBR) configured to receive a fluid containing selenium and to process the fluid via a first biofilm disposed on a first media to produce a first MBBR fluid by removing nitrogen from the fluid. The system further includes a second anoxic MBBR fluidly coupled to the first MBBR to receive the first MBBR fluid and to process the first MBBR fluid via a second biofilm disposed on a second media to produce a selenium enriched fluid, followed by a solid-liquid separation system to remove selenium in solid form as sludge and produce a treated effluent containing equal to or less than 5 micrograms of selenium per liter. The system includes a plurality of first sensors and first actuators disposed on the first MBBR, and a plurality of second sensors and second actuators disposed on the second MBBR.