A method for wastewater treatment having a zero discharge of sludge, the method including: a) providing a membrane bioreactor system including a membrane separation system and a reaction vessel; and b) aerating the membrane separation system and the reaction vessel to control the dissolved oxygen concentration around the membrane separation system to be greater than 0 and smaller than 2 mg/L and the dissolved oxygen concentration in the reaction vessel excluding the membrane separation system to be greater than 0 and smaller than 1 mg/L. A wastewater treatment system having a zero discharge of sludge includes a membrane bioreactor system including: a reaction vessel, a membrane separation system, a water production system, and an aeration system.

The present disclosure relates to recycling automotive phosphate rinse water. An apparatus and method is disclosed for treating process water containing phosphate. The apparatus may include a process water line. The process water line may be in fluid communication with a sample process water line. The sample process water line may be in fluid communication with a dilution line. The sample process water line, the dilution line, and a phosphate analyzer may be in fluid communication with a diluted process water line. The apparatus may also include a chemical additive feed line in fluid communication with the process water line downstream from the sample process water line.

A method including directing an aqueous solution having dissolved carbon dioxide and dissolved ozone into a vessel, removing an amount of the dissolved carbon dioxide and irradiating the effluent with ultraviolet light to decompose an amount of the dissolved ozone is disclosed. The method may include removing the dissolved carbon dioxide by controlling pH. The method may include removing the dissolved carbon dioxide by contact with a membrane degasifier. A system including a channel fluidly connectable to a source of an aqueous solution having dissolved carbon dioxide and dissolved ozone, a dissolved carbon dioxide removal subsystem, and a source of ultraviolet irradiation is also disclosed. The dissolved carbon dioxide removal subsystem may include a source of a pH adjuster. The dissolved carbon dioxide removal subsystem may include a membrane degasifier.

Provided is a non-linear model predictive control (NMPC) system for automatic and optimum start-up of an anaerobic digestion (AD) system. The NMPC provides an optimum set of values of manipulated variables for controlling some of the key AD process variables during start-up. The NMPC based automatic start-up system was evaluated against a virtual AD process plant scenario involving a high rate AD reactor treating a readily biodegradable carbohydrate based substrate.

This disclosure includes systems and methods for optimizing aeration in wastewater treatment. The techniques described herein include receiving data for a wastewater treatment plant, the data being descriptive of water quality over a period of time. The techniques further include developing a predictive model for future water quality based on the received data. The techniques also include determining, based on the predictive model, a plurality of DO setpoints and airflow rates for the wastewater treatment plant. The techniques further include controlling an aeration system for the wastewater treatment plant using the plurality of DO setpoints and the airflow rates.

A method and system for operating a seal gas compressor utilized in a direct reduction process including: monitoring a pH level of a water stream used in the seal gas compressor, wherein the pH level of the water stream is affected by a reformer flue gas stream that comes into contact with the water stream, wherein the monitoring step is carried out one or more of upstream of the seal gas compressor and downstream of the compressor; and adjusting the pH level of the water stream to maintain the pH level of the water stream within a predetermined range based on feedback from the monitoring step. The method includes maintaining the pH level of the water stream upstream of the seal gas compressor in a range between 7.5 and 10 and maintaining the pH level of the water stream downstream of the seal gas compressor in a range between 7.8 and 9.5.

In a system for decomposing organic compounds in water for use in semiconductor manufacturing, a chemical reactor vessel having a fluid inlet and a fluid outlet, a persulfate anion addition system upstream of the reactor vessel, and a light emitting device contained within the reactor vessel. The light emitting device provides light capable of decomposing persulfate anions.

Systems and methods can support an autonomous pool skimming system. The pool skimming system may have a body with two or more hulls. Two or more paddlewheels may be coupled to the body. An independent motor may drive each paddlewheel. The motors may be independently controllable to support steering. The pool skimming system may have one or more processing units, two or more distance sensors, one or more solar cells, and a power supply operable to power the processing units and the motors from energy supplied by the solar cells. One or more processing modules may configure the processing units to plan and execute a traversal path across the surface of a body of water, such as a swimming pool, to collect debris into a removable basket. A portion of the traversal path may be established according to signals from distance sensors.

A phosphorus-based calcification inhibitor (“inhibitor”) configured to prevent calcification of anaerobic granular sludge.

Methods to remediate a contaminated material are provided. In one embodiment, a biocatalyst that digests hydrocarbon contaminants is activated with a nutrient and the activated biocatalyst is combined with the contaminated material and water to form a mixture. The mixture is incubated for a period of time, and the level of contaminant in the mixture is determined to ascertain whether to incubate further, add additional biocatalyst mix, or provide the remediated material for further processing. In one embodiment, the remediated material is provided for reuse or recycling with a second material, such as a construction aggregate. The method is particularly suited for remediation of drill cuttings, mine tailings, hydrocarbon-contaminated soil, and the like.