A method of separating and recovering a cobalt salt and a nickel salt includes a separation step of separating, by using a nanofiltration membrane, a cobalt salt and a nickel salt from a rare metal-containing aqueous solution containing at least both the cobalt salt and the nickel salt as rare metals, in which the nanofiltration membrane has a glucose permeability of 3 times or more a sucrose permeability, the sucrose permeability of 10% or less, and an isopropyl alcohol permeability of 50% or more when a 1,000 mg/L glucose aqueous solution, a 1,000 mg/L sucrose aqueous solution, and a 1,000 mg/L isopropyl alcohol aqueous solution, each having a pH of 6.5 and a temperature of 25° C., individually permeate through the nanofiltration membrane at an operating pressure of 0.5 MPa.

A method and system of providing ultrapure water for semiconductor fabrication operations is provided. The water is treated by utilizing a free radical scavenging system. The free radical scavenging system can utilize actinic radiation with a free radical precursor compound, such as ammonium persulfate. The ultrapure water may be further treated by utilizing ion exchange media and degasification apparatus. A control system can be utilized to regulate a continuously variable intensity of the actinic radiation.

A method and system of providing ultrapure water for semiconductor fabrication operations is provided. The water is treated by utilizing a free radical scavenging system. The free radical scavenging system can utilize actinic radiation with a free radical precursor compound, such as ammonium persulfate. The ultrapure water may be further treated by utilizing ion exchange media and degasification apparatus. A control system can be utilized to regulate a continuously variable intensity of the actinic radiation.

Disclosed is a method for recovering phosphorus from sludge rich in chemical phosphorus precipitates using a high-protein biomass waste, comprising introducing the sludge rich in chemical phosphorus precipitates into an anaerobic fermenter, adding a certain amount of a high-protein biomass by-product, sealing the fermenter and fermenting for 4-7 days. The method can effectively increase the phosphorus release efficiency from the sludge, and also generate volatile short-chain fatty acids and ammonia nitrogen in high concentrations. After dewatering, phosphorus and part of ammonia nitrogen can be recovered in a form of high-purity struvite crystals only by addition of a magnesium salt and adjustment of pH to 7.5-9.0. The volatile short-chain fatty acids can be used as an economical carbon source. The method allows simultaneous utilization of two solid wastes to recover carbon, nitrogen and phosphorus resources, and can reduce the usage of chemical reagents, saving the treatment cost.

The invention is directed to a control method for a process to convert bisulphide to elemental sulphur in an aqueous solution comprising sulphide-oxidising bacteria wherein the process is controlled by applying a potential between the anode electrode and the cathode electrode or between the anode electrode and the reference electrode of an electrochemical cell resulting in a current between the cathode electrode and the anode electrode, measuring a current as measured by an electrochemical cell and adapting the process in response to the measured current. The process to convert bisulphide may comprise the following steps: (a) contacting bisulphide with oxidised sulphide-oxidising bacteria in the aqueous solution and elemental sulphur, (b) oxidizing the reduced sulphide-oxidising bacteria, (c) using the oxidised sulphide-oxidising bacteria obtained in step (b) in step (a) and (d) isolating elemental sulphur from the aqueous solution obtained in step (a) and/or step (b).

Provided are a household toilet waste treatment system and a method of treating toilet waste using the same, the household toilet waste treatment system comprising a solid-liquid separation toilet, a biological treatment apparatus, a sterilization apparatus, and a combustion apparatus. The combustion apparatus complements a slow biological treatment apparatus to allow continuous treatment of the household toilet waste in a unit space without long-distance piping connections.

Provided are a household toilet waste treatment system and a method of treating toilet waste using the same, the household toilet waste treatment system comprising a solid-liquid separation toilet, a biological treatment apparatus, a sterilization apparatus, and a combustion apparatus. The combustion apparatus complements a slow biological treatment apparatus to allow continuous treatment of the household toilet waste in a unit space without long-distance piping connections.

Disclosed is a system and method for cooperatively treating water and gas to reduce pollutants and carbon emission. The system includes a flue gas pre-treatment unit, a wastewater pre-treatment unit, a gas-water cooperative cleaning unit, a remaining water treatment unit, and a circulating cooling evaporation unit.

Disclosed is a system and method for cooperatively treating water and gas to reduce pollutants and carbon emission. The system includes a flue gas pre-treatment unit, a wastewater pre-treatment unit, a gas-water cooperative cleaning unit, a remaining water treatment unit, and a circulating cooling evaporation unit.

A chemical dosing optimization apparatus includes a chemical dosing optimization part and a chemical dosing output control part, wherein the chemical dosing optimization part receives real-time data at least from a water treatment plant treating feed water by dosing a chemical and providing a treated water, analyzes the real-time data through a water treatment model in response to receiving the real-time data, derives a prediction value for predicting a state of the treated water of the water treatment plant, and derives a control value based on the prediction value through a controller, such that the control value is to set a minimum of a chemical dosage to be dosed in the feed water while the state of the treated water of the water treatment plant is maintained in a normal range, and wherein the chemical dosing output control part provides the control value to a water treatment control device.