Mainstream partial nitritation was studied at 10° C. in a moving bed biofilm reactor treating synthetic wastewater containing both nitrogen (≈40 mg L-1) and organic carbon at COD/N ratio ranging from 1.3 to 2.2. Three different control strategies were investigated to achieve partial nitritation. Initially, biofilm age was controlled by incorporating a media replacement strategy. Next, separately from the media replacement, oxygen limited conditions were investigated and finally pH control was incorporated together with oxygen limitation. Successful partial nitritation was achieved only by combining oxygen limitation with pH control. The average NH4-N concentration was equal to 16.0±1.6 mg L-1 and average NO2-N concentration was equal to 15.7±2.4 mg L-1 during steady state partial nitritation. The average residual NO3-N concentration was equal to 2.6±2.2 mg L-1. The results obtained from this study prove for the first time that partial nitritation can be successfully controlled in a biofilm reactor treating wastewater with low nitrogen concentration, relatively high COD/N ratio and at low temperature. An algorithm for dynamic process control of partial nitritation has been also developed.

A system for treating and/or recycling gray water includes a first receiving tank for gray water, a second receiving tank for treated water and a fluidic treatment circuit between the first and second receiving tanks. The first receiving tank includes an element for oxygenating the water in the first receiving tank and a system adapted to deliver enzymes into the first receiving tank. The fluidic treatment circuit includes a filtration unit, a microfiltration unit including at least one microfilter, a disinfection unit and a membrane ultrafiltration unit.

A wastewater treatment plant and related method comprise a treatment stage including a biological-process substage configured for growing unicellular organisms adapted to reduce contaminants in the wastewater which are dissolved, including at least one of organic matter and nitrogenous matter, by digestion thereof, and which are adapted to floc after digestion and a floc-removal substage downstream from the biological-process substage, relative to the flow of wastewater, and configured for substantially removing the unicellular organisms that have flocked. The treatment stage is configured to form majority and minority flows of treated wastewater, and the minority flow is configured to be recycled upstream of the biological-process treatment substage. The plant includes a heat transfer assembly configured for transferring heat from the majority flow of treated wastewater to the minority flow thereof to increase temperature of wastewater to be treated.

Systems and methods for aeration and mixing processes are disclosed.

Disclosed herein are systems and processes for treating a Waste Stream comprising biosolids, the Waste Stream provided at varying flow rates and solids concentrations so as to achieve an SOUR of 1.5 mg O.sub.2/g/hr or less and an ORP of at least +300 mV. The system includes a biosolids manipulation device to adjust the volume of suspended solids as a percent of the total volume of the Waste Stream to five (5) percent or less; a chemical oxidant feed device to dose the Waste Stream with an oxidant such as chlorine dioxide, ozone, or similar oxidant, and a treatment vessel associated with said chemical oxidant feed device through which said Waste Stream flows, wherein said chemical oxidant feed device and said treatment device are configured so as to achieve a dose rate between 25 and 200 parts per million of the Waste Stream and substantially complete mixing of the oxidant within 30 seconds of dose delivery in the treatment vessel.

Methods, systems, and computer-readable media that implement a mobile filtration system that provides sustainable, on-demand water filtration while supporting the growth and maintenance of organisms. The method includes determining an environmental parameter associated with a volume of water, determining, based on the determined environmental parameter, a control parameter for an autonomous submersible structure that includes a platform on which marine life grows, and generating, based on determining the control parameter, an instruction for the autonomous submersible structure.

Systems and methods for enabling dynamic volumetric transitioning and segmentation of treatment conditions are disclosed. Such treatment conditions may include, by way of example, systems and methods for dynamically transitioning treatment environments within a reactor for activated sludge treatment processes. Such environments may include anaerobic, anoxic, fermentation, suboxic, and aerobic environments.

A water treatment control system includes an aerobic tank in which aerobic treatment is carried out, an aerobic tank aeration device that aerates to-be-treated water in the aerobic tank, a membrane filtration tank including a separation membrane that filters the to-be-treated water treated in the aerobic tank, a membrane filtration tank measurement instrument that measures the ammonia concentration of the to-be-treated water in the membrane filtration tank, as a membrane filtration tank ammonia concentration measurement value, and an aerobic tank aeration air volume calculation device that sets the aerobic tank aeration air volume of the aerobic tank aeration device on the basis of the membrane filtration tank ammonia concentration measurement value.

The disclosure relates to a method for enhancing methanogenesis in anaerobic digestion of municipal sludge by utilizing a filter screen structure, comprising: arranging a filter screen structure with titanium or titanium alloy as the framework and Fe.sub.3O.sub.4 as the coating in the anaerobic digestion system to accelerate the rate of hydrolysis and acidification, and increase the proportion of methane in biogas. Compared with the prior art, the disclosure increases the contact between Fe.sub.3O.sub.4 and anaerobic microorganisms by means of the screen structure; the stable crystal structure of Fe.sub.3O.sub.4 ensures the sustainability as an electron carrier while enriching electroactive microorganisms; titanium or titanium alloy, as a material with high strength, corrosion resistance, good biocompatibility, and good conductivity, can form a good match with Fe.sub.3O.sub.4 and assist in promoting the electron transfer; the disclosure has the advantages of low cost, high income, no need of repeated dosing and stable effect, and could strengthen the oxidation and decomposition of organic matter in the anaerobic digestion, accelerate the rate of methanogenesis, and increase the gas production.

A spore germination composition and method to produce a bioaugmentation solution that is added to an anaerobic digester or partially aerobic digester to increase biogas production. A nutrient-germinant composition comprises L-amino acids a phosphate buffer, an industrial preservative, and an optional source of potassium. The composition and spores of one or more Bacillus species are heated to a preferred elevated temperature range of 35° C. to 60° C. for an incubation period of around 20 to 60 minutes to form a bioaugmentation solution that is dispensed to the digester, preferably to the hydrolysis stage of the digester. A dose of bioaugmentation solution is added to the digester around once per day in an amount to provide at least 1000 CFU per mL of the full volume capacity of the digester, which can increase methane production by around 5 to 10% over operation of the digester without the bioaugmentation solution.