A system and method for removing contaminates from greywater that uses carbon dioxide (CO.sub.2) and a system that adjusts the pH between 6 and 9. The filtration system is cost effective, quick, and easy to use, resulting in purified water.

A method and apparatus are disclosed for carbon dioxide removal and sequestration from ambient air or point source emissions by integration of four self-sufficient systems including a PEO renewable energy generation system, a desalination system, a pH-swing hydration or a direct hydration system, and a bicarbonate fixed, and alkalinity enhanced dense brine sequestration system, in which, the synergy between the PEO energy generation system and other three systems including provision of all needed renewable energy for operation of other three systems, the synergy between the desalination and other systems including provision of freshwater needed for the PEO energy generation system and the pH-swing system, as well as provision of a dense brine fluid from the desalination system to the pH-swing or the direct hydration system, and in the case of available freshwater supply where the desalination system can be avoided.

The wastewater treatment apparatus of present invention has an electro-coagulation unit for removing contaminants with at least one anode and at least one cathode and an electro-oxidation unit for oxidizing contaminants with at least one anode and at least one cathode wherein oxidants are electrochemically generated. Based on the type of wastewater, the apparatus can have an electro-flotation unit between the electrocoagulation unit and the electro-oxidation unit. The apparatus also has an oxidant removal unit which can have a metal ion-liberating electrode for reacting with and removing residual oxidants. In some cases, portions of effluent from the oxidant removal unit can be recirculated to the electro-coagulation unit for increased efficiency.

The invention relates to a method for treating organic waste, in particular to a method for treating sludge from wastewater treatment plants, in order to produce power and/or hygienized organic matter, including a first step of mesophilic or thermophilic digestion (13) of at least one fraction of a stream of organic waste, and comprising the following steps: dehydrating (15) all of the digested and non-digested waste; aerated thermal hydrolysis (16) of the dehydrated waste, including an injection of an oxidizing agent in a quantity lower than the stoichiometric quantity for oxidizing organic matter, and setting to the required temperature by a heating means; and a second mesophilic or thermophilic digestion (17) of the stream of hydrolyzed waste.

Method and system for treating wastewater includes treating sludge with ozone in a plug-flow type reactor to cause lysis of biosolids in the sludge. The ozonated sludge may be provided to an anaerobic or anoxic section of the wastewater treatment system to aid the denitrification processes occurring in the anaerobic or anoxic section of the wastewater treatment system or to other sections of the wastewater treatment system such as a fermenter, an aerobic digester, or an anaerobic digester.

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.

A system and method for removing contaminates from greywater that uses carbon dioxide (CO.sub.2) and a system that adjusts the pH between 6 and 9. The filtration system is cost effective, quick, and easy to use, resulting in purified water.

The present invention relates to a method for increasing the magnesium ion concentration of feed water. The method comprises the steps of providing an inlet flow of feed water (Q.sub.IN), increasing the concentration of carbon dioxide in said inlet flow Q.sub.IN to obtain a flow of carbon dioxide-containing feed water (Q.sub.CO2), and passing said flow Q.sub.CO2 through a solid bed comprising a magnesium ion source to obtain an outlet flow of treated water (Q.sub.OUT) having an increased concentration of magnesium ions. The invention further relates to a water treatment system for increasing the magnesium ion concentration of feed water and a corresponding flow reactor.

This disclosure relates to a method, system and apparatus for inactivating microorganisms in an aqueous solution. The method comprises passing bubbles of a gas through the aqueous solution, wherein the gas comprises at least 10% CO2 by volume and has a temperature of at least 18° C. The system comprises a gas supply to supply gas comprising at least 10% CO2 and having a temperature above 18° C., a gas-delivery apparatus to receive the gas and deliver it into the aqueous solution in the form of bubbles. The apparatus comprises a gas-permeable material having a flow surface configured to enable the flow of the aqueous solution across the flow surface, a chamber arranged at an opposite side of the gas-permeable material to supply a gas that inactivates microorganisms such that the gas is able to pass through the gas-permeable material and into the aqueous solution as gas bubbles.

A device for integrated control of acid wastewater plugging and discharging of an abandoned mine includes an airtight wall, a central controller, a CO.sub.2 gas source, an agent bucket, a siphon pipe I and a liquid storage bucket are arranged on the outer side of the airtight wall, and a plurality of monitoring sensors are arranged in the inner side of the airtight wall, and the monitoring sensors are electrically connected to the central controller; and a flood discharge valve is arranged at the bottom of the airtight wall. The device is miniaturized and operates for a long time with low power consumption, thereby achieving long-term unattended operation and maintenance.