A waste liquid treatment device (20) treats water to be treated that contains at least hydrogen peroxide, by decomposing the hydrogen peroxide. The waste liquid treatment device (20) is equipped with a housing (21), an introduction port (22) that is provided to the housing (21) and that introduces the water to be treated into the housing (21), a discharge port (23) that is provided to the housing (21) and that discharges treated water to be obtained by treating the water to be treated, and one or more channel-defining members (24) that are disposed within the housing (21) and that have a surface that a catalyst is disposed on, wherein the one or more channel-defining members (24) define, between the introduction port (22) and the discharge port (23), a channel (P) for the water to be treated, the channel (P) having a turning in at least one position.

A method of removing particulate silicon from an effluent water in accordance with various embodiments may include: adding a base to the effluent water, an amount of the added base being sub-stoichiometric with regard to a basic oxidation reaction of an entire amount of silicon contained in the effluent water to ortho-silicic acid or ortho-silicate ions; maintaining a resulting mixture of the effluent water and the base in a predetermined temperature range for a period of time, so that a sediment including silicon is formed; and separating the sediment and the effluent water from each other.

A method for treating a waste stream from a copper CMP process including dissolved copper and abrasive particles having a number weighted mean size of less than 0.75 μm includes introducing the waste stream into a feed tank, flowing the waste stream from the feed tank into an ultrafiltration module, filtering the waste stream through a membrane of the ultrafiltration module to form a solids-lean filtrate, directing the solids-lean filtrate from the ultrafiltration module through an ion exchange unit to remove dissolved copper and produce a treated aqueous solution having a lower copper concentration than the copper concentration of the waste stream, backwashing the membrane ultrafiltration module to remove the slurry solids from the membrane of the ultrafiltration module, and combining the removed slurry solids with the treated aqueous solution to form a combined discharge stream having a copper concentration suitable for discharge into the environment.

The present invention provides a method for treating a copper-containing waste etching solution, which includes: preparing basic copper chloride nanometer seed crystals and synthesizing basic copper chloride mono-crystals; making an acidic waste etching solution subjected to agglomeration reaction with an ammonium-containing solution and slurry containing the basic copper chloride mono-crystals to obtain basic copper chloride crystal particles and copper-removed waste solution; making an alkaline waste etching solution react with sulfuric acid to obtain a copper sulfate mixed solution; and then evaporating, concentrating, cooling and crystallizing the copper sulfate mixed solution obtained by the reaction of the alkaline waste etching solution and the sulfuric acid in sequence to obtain copper sulfate pentahydrate solids. In a case of low investment, the present invention not only can realize the recycling of copper in the copper-containing waste etching solution, but also can obtain various high-value products, and can achieve both environmental and economic benefits.

The invention relates to a method for the precipitation of arsenic and heavy metals from acidic, in particular sulphuric acid, process water (12), containing both arsenic and heavy metals, comprising a precipitation method phase (II) with a sulphide precipitation stage (C) in which arsenic and at least one primary heavy metal are precipitated together, wherein a sulphide precipitating agent (16) is added to the process water (12) such that arsenic is precipitated as arsenic sulphide and the at least one primary heavy metal is precipitated as metal sulphide. The sulphide precipitation stage (C) comprises a first sulphide precipitation step (C.1) in which a sulphide precipitating agent is added to the process water (12) in a first sulphide precipitation reactor (14), whereby an intermediate fluid (22) is generated still containing arsenic or still containing arsenic and the primary heavy metal. The intermediate fluid (22) is transferred into a second sulphide precipitation reactor (30) after the first sulphide precipitation step (C.1). The sulphide precipitation stage (C) comprises a second sulphide precipitation step (C.2) in which a sulphide precipitating agent is added to the intermediate fluid (22) in the second precipitation reactor, whereby a residual fluid (32) is generated which is substantially free from arsenic.

Abrasive material regeneration method regenerates a cerium oxide abrasive material from a used abrasive material slurry containing the cerium oxide abrasive material and resulting from grinding a grinding subject having silicon as the primary component, characterized by regenerating the abrasive material containing cerium oxide through: a slurry recovery step (A) for recovering an abrasive material slurry discharged from a grinder; an isolation/concentration step (B) for adding a magnesium salt as an inorganic salt to the recovered abrasive material slurry, aggregating the abrasive material under the condition that the pH value of the mother liquor converted to 25 DEG C is at least 6.5 and less than 10.0, and thus isolating and concentrating the abrasive material from the mother liquor; and an abrasive material recovery step (C) for recovering the isolated and concentrated abrasive material.

A system for providing treated water includes a water treatment unit including an inlet water quality probe, a worker bed, a probe to measure a parameter of water from the worker bed, a polisher bed connected downstream from the worker bed and having a probe to measure a parameter of water from the polisher bed, and a flow meter upstream of the worker bed or downstream of the polisher bed. A controller in communication with the flow meter and the probes is configured to receive data from same. A remote server in communication with the local water treatment unit is configured to receive data from the local water treatment unit. The controller or the server may determine a cumulative flow total, a billing cycle flow total, a current exchange flow total, a contaminant load, or a remaining capacity of the water treatment unit.

Water treatment systems are disclosed. The system includes an electrochemical cell having an inlet and an outlet, a cathode comprising a catalytic material for electrochemical generation of persulfate free radicals, and an anode, a source of a persulfate positioned upstream of the electrochemical cell, first contaminant concentration sensor positioned upstream of the electrochemical cell, and a controller operatively coupled to receive one or more input signals from at least the first contaminant concentration sensor. Methods of treating water using the electrochemical cell disclosed herein are disclosed. Methods of facilitating water treatment by providing the electrochemical cell disclosed herein are disclosed. Methods of retrofitting a water treatment system having an AOP by providing the electrochemical cell disclosed herein are disclosed.

A method and system of treating a liquid stream is provided. The water is treated by utilizing a free radical scavenging system and a free radical removal system. The free radical scavenging system can utilize actinic radiation with a free radical precursor compound, such as ammonium persulfate. The free radical removal system can comprise use of a reducing agent. The water may be further treated by utilizing ion exchange media and degasification apparatus. A control system may be utilized to measure and regulate addition of the precursor compound, the intensity of the actinic radiation, and addition of the reducing agent to the water.

Provided is a biological treatment method and an apparatus that allow organic wastewater from a manufacturing process of electronic devices to be neutralized efficiently during its biological treatment with a less neutralizer in contrast to excessive use thereof in the conventional biological treatment and thereby make it possible to reduce an amount of an inorganic coagulant used in the downstream coagulation step and to reduce salt loads in RO membrane separation and ion exchange treatment. Wastewater from a process of manufacturing electronic devices is passed sequentially through two or more biological treatment tanks that include at least two aerobic biological treatment tanks including the final-stage aerobic biological treatment tank while adding a neutralizer to the biological treatment tank or tanks except the final-stage biological treatment tank so that an M-alkalinity of the liquid in the final-stage biological treatment tank is maintained at not more than 50 mg/L as CaCO.sub.3.