The present invention provides a method for suppressing a decrease in the concentration of an isothiazoline compound, wherein even if an addition concentration of the isothiazoline compound used as an antibacterial agent is low in a water system, the decrease in the concentration thereof can be suppressed so that the residual rate thereof after 24 hours can be raised. The method is carried out in a manner wherein to a water system, an isothiazoline compound is fed with an addition concentration of 0.2 mg/L or more and less than 1 mg/L, and a combined chlorine agent consisting of a chlorine stabilizer and a chlorine-based oxidant is added so as to maintain a concentration thereof at 0.3 mg/L as Cl.sub.2 or more and 6 mg/L as Cl.sub.2 or less therein.

A composition and method for dispersing sulfur, cleaning sulfur deposits, and minimizing foaming in an aqueous system is disclosed. The method may include adding a first sulfur dispersant to process water containing sulfur and dispersing the sulfur. The first sulfur dispersant may include a C.sub.5-C.sub.25 alkyl polyglycoside. A second sulfur dispersant may also be added to the process water. The second sulfur dispersant may include a polymer of acrylic acid and 2-acrylamido-2-methylpropane sulfonic acid.

Devices for controlling to remove food waste digestion foam are provided. The device includes a digestion tank. The digestion tank includes two hermetically sealed boxes. Each of the two boxes is opened with a liquid inlet connected to an interior of each of the two boxes. A conveying mechanism is connected between the two boxes. The conveying mechanism conveys a gas in the two boxes in a reciprocal manner. The gas in the two boxes is conveyed in the reciprocal manner through the conveying mechanism to generate a pressure difference between the two boxes distributed left and right to remove the foam, which adopts physical defoaming without adding any reagent, is cost-effective and efficient, and does not affect an anaerobic reaction process due to addition of a chemical defoaming agent. The entire device has a simple structure and is easy to operate, and the process is controllable.

Embodiments of the disclosure provide a foam fractionation method and system that include a foam collection container having a body, a collection tube coupled to the collection container, and a foam collection conduit coupled with foam removal piping disposed within a chamber formed by the body of the collection cone. The collection container and the collection tube are coupled to allow for pressurization within the chamber. A mouth of the foam collection conduit is operable to receive foam.

The wastewater treatment process by using activated sludge process often appear the sludge bulking fault phenomenon. Due to production conditions of wastewater treatment process, the correlation and restriction between variables, the characteristics of nonlinear and time-varying, which lead to hard identification of sludge bulking; Sludge bulking is not easy to detect and the reasons resulting in the sludge bulking are difficult to identify, are current RBF neural network is designed for detecting and identifying the causes of sludge volume index (SVI) in this patent. The method builds soft-computing model of SVI based on recurrent RBF neural network, it has been completed to the real-time prediction of SVI concentration and better accuracy were obtained. Once the fault of sludge bulking is detected, the identifying cause variables (CVI) algorithm can find the cause variables of sludge bulking. The method can effectively identify the fault of sludge bulking and ensure the safety operation of the wastewater treatment process.

The present invention relates to apparatus, methods, and applications for treating wastewater collection systems contaminated with fats, oils and grease (FOG), such as wet wells, transfer or lift stations, or main sewer lines, and more particularly to biological processes for removing the FOG from wastewater. This invention further relates to apparatus and methods for growing microbes on-site at a wastewater treatment facility or FOG-contaminated wastewater collection system location, and for economically inoculating sufficient microbes to solve various treatment problems rapidly.

A two-step process for recovering useable solids from food processing wastewater and for significantly reducing the pollutants, chemical, bacterial, and viral load. The first step is the addition of pretreatment chemicals such as metal-based coagulant, pH adjuster, oxidant or a combination thereof. The second step is pumping the chemically pretreated wastewater into a foam fractionation system where a gas is introduced into the chemically treated wastewater to create a rising foam that captures and remove solid materials from the remaining wastewater effluent. The solids are recovered for additional post-processing and the effluent is discharged for post-processing or to existing bodies of water.

The present invention relates to apparatus, methods, and applications for treating wastewater, and more particularly to biological processes for removing pollutants from wastewater. This invention further relates to apparatus and methods for growing microbes on-site at a wastewater treatment facility, and for economically inoculating sufficient microbes to solve various treatment problems rapidly

The present invention relates to a device and a process for purification of grey water and recovery of surfactants and purified water. In particular the invention relates to in-home purification of grey water generated from laundry wash and/or rinse liquor and recovery of surfactants and purified water for water saving by re-use.

A method for using foam fractionation to remove a PFAS contaminant from a water source is disclosed herein. The method includes providing a feed stream to an inlet of an active column, where the feed stream comprises the PFAS contaminant and water; introducing the feed stream into an interior of the active column; flowing gas through an active column into the interior of the active column; rising gas through the feed stream in the interior of the active column to form gas bubbles in the feed stream; forming a foam layer; passing the purified stream into a next column; continuously perform foam fractionation until the feed stream becomes a cleaned stream; collecting the foam layer; and disposing of the foam layer.