Methods are provided for improved recovery of organic salts, such as ionic liquids or organic salts comprising quaternary organic cations, in an industrial alumina production process, such as the Bayer process. These methods include (i) using an organic salt for the removal of impurities in an industrial process for the production of alumina; (ii) subjecting the spent organic salt to a recycling operation that generates at least one exit stream having a measureable amount of the organic salt {e.g., by entrainment or by solubility of the organic salt in the exit stream); (iii) collecting and treating the exit stream (s) with an inorganic salt, in an amount effective to induce phase separation; and (iv) recovering the organic phase containing the recovered organic salt. These methods and compositions allow alumina refinery plants to use organic salts for removal of industrial process streams in an economical manner, due to the efficient recovery of the organic salt.

Described herein are methods of treating fluid comprising hydrocarbons, water, and polymer being produced from a hydrocarbon-bearing formation are provided. The method can include adding a concentration of a viscosity reducer to the fluid to degrade the polymer present in the fluid and adding a concentration of a neutralizer to the fluid to neutralize the viscosity reducer in the fluid. The viscosity reducer is buffered at a pH of 7 or less (e.g., at a pH of from 2 to 7, such as at a pH of from 3.5 to 7, or at a pH of from 5 to 7). The addition of the concentration of the viscosity reducer is in a sufficient quantity to allow for complete chemical degradation of the polymer prior to the addition of the concentration of the neutralizer in the fluid such that excess viscosity reducer is present in the fluid. The addition of the concentration of the neutralizer is sufficiently upstream of any surface fluid processing equipment to allow for complete neutralization of the excess viscosity reducer such that excess neutralizer is present in the fluid prior to the fluid reaching any of the surface fluid processing equipment.

The present invention relates to a process for purifying a wastewater stream WW1 contaminated with nitrobenzene, comprising (I) stripping of the wastewater stream WW1 with a stripping gas SG1 in a continuously operated stripping column to obtain a wastewater stream WW2 which contains nitrobenzene in a concentration reduced relative to WW1 (c.sub.NB,WW2), (II) further purification of the wastewater stream WW2 in a wastewater treatment plant, wherein a target value (c.sub.NB,WW2,TARGET) is specified for the concentration of nitrobenzene in the wastewater stream WW2, which is greater than zero but takes into account the requirements of the wastewater treatment plant for the maximum content of nitrobenzene in the wastewater streams supplied thereto, wherein, for at least one combination of specified boundary conditions of (a) nitrobenzene concentration in WW1, (b) the temperature of WW1, and (c) the temperature of SG1, a set of linear mathematical relationships of the type m.sub.SG1=x.Math.m.sub.WW1 is stored in a database, which linear mathematical relationships define a range of concentrations of nitrobenzene in WW2, wherein the set comprises, in addition to a mathematical relationship (0) which corresponds to the target value c.sub.NB,WW2,TARGET, at least a first mathematical relationship (1) for a first value of c.sub.NB,WW2, which corresponds to 98% of the target value c.sub.NB,WW2,TARGET, and a second linear mathematical relationship (2) for a second value of c.sub.NB,WW2, which corresponds to 102% of the target value c.sub.NB,WW2,TARGET, and wherein the flow rate of the stripping gas is adapted to the flow rate of the wastewater WW1 such that the flow rate of WW1 is within a range of values (AB) that is generated by the first mathematical relationship (1) and the second mathematical relationship (2) at the respective flow rate of WW1, and controlling the concentration of nitrobenzene in WW2 (c.sub.NB,WW2) by adjusting the flow rate of stripping gas SG1 accordingly in the event of a measured actual value of this concentration which is outside a window of >98% to <102% of the target value.

In one embodiment, a system includes a disinfection system configured to disinfect a first fluid. The system further includes a moving bed biofilm reactor (MBBR) system configured to treat a second fluid, wherein the disinfection system is fluidly coupled to the MBBR system upstream of the MBBR system, downstream of the MBBR, or wherein the disinfection system is disposed in the MBBR system.

Disclosed herein is a process for de-watering a sludge. The process comprises heating a de-watering fluid, and passing the de-watering fluid through the sludge, thereby de-watering the sludge. Also disclosed herein is a system for de-watering a sludge and a sludge which is at least partially de-watered according to the process.

The disclosure provides two integrated methods for the production of potable water from seawater or other brackish waters using chemical forced precipitation. The process is closed loop. It recycles process reactants and produces commercially valuable potable water and salts. The technology uses a computer software method of process variable control that maintains the chemical forced precipitation process salt, solvent, and water concentrations as required to optimize water production. The process fortuitously requires less energy than other water production processes and can utilize solar hot water heating or waste heat from other combustion and seawater for heating and cooling energy sources.

A system and a method for separation of ions from ions-containing medium is disclosed herein, that utilizes capacitive-faradaic fuel cells (CFFC) particles coated at least partially with catalysts capable of catalyzing redox reactions provided a reductant (fuel) and/or an oxidant, thereby polarizing the particles to more effectively absorb charged species (ions) from the water upon introducing, e.g., H.sub.2 gas or O.sub.2 gas, in the medium during the adsorption or regeneration. The same concept is utilized in a hybrid electrochemical cell for providing a system and a method for generating and converting electrochemical energy.

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 plasma water treatment apparatus includes a plasma generator that generates plasma in water, and a porous dielectric that adsorbs nitrogen oxide generated in the water, surrounds the plasma generator, and includes silicon dioxide powder and carbon powder, thereby removing color of wastewater.

Disclosed is a method of decomposing ozone in ozone water. According to the present invention, a temperature of ozone water is increased by mixing ozone water with heated water, and the ozone in the ozone water is decomposed into oxygen by the increase in the temperature.