Provided herein are membrane separation systems and methods suitable for use in separating carbonylation catalyst from a beta-lactone product stream. Such membrane separation systems utilize a cross flow separation technique and employ a sweep stream.

Multiple chemical dosing levels of differing chemical dosages are set. When control is initiated, chemical dosing is started at the level with the highest chemical dosage. Each time a sampling period S passes, the rate of increase in the pressure difference of an RO system is compared with a threshold value A. When the rate of increase is at or below the threshold value A, the chemical dosage is reduced to the level that is one step lower. When the rate of increase is greater than the threshold value A, the chemical dosage is increased to the level that is one step higher.

A gas separation system for controlling a concentration of a first gas species and a second gas species in an outlet gas comprises a splitter unit. The splitter unit comprises a gas membrane system having a gas inlet port. The gas inlet port is in fluid connection with an air intake. A membrane is a selective barrier and allows some things to pass through but stops others.

A new apparatus, system and method to purified produced water and removed valuable metals and minerals is described. The apparatus comprises a device for flowing produced water wellbore from a wellbore to the produced water purification apparatus; at least one device to remove heavy metals from the produced water; at least one brine removal device to remove brine from the produced water. The method comprises steps to use the apparatus and the system comprises a control panel that operates the at least one device for removing heavy metals and at least one sensor in a coordinated manner.

Biocide can be controllably added to a feed stream for a membrane. The membrane can separate the feed stream into a purified permeate stream and a concentrate stream containing contaminants from the feed stream. In some examples, a charge neutral biocide is introduced into the feed stream at a first addition rate. The concentration of the charge neutral biocide in the permeate stream is measured to provide a measured concentration of the charge neutral biocide in the permeate stream. The addition rate of the charge neutral biocide can be adjusted based on the measured concentration of the charge neutral biocide in the permeate stream to introduce charge neutral biocide into the feed stream at a second addition rate different than the first addition rate.

Embodiments of the disclosure provide a method for evaluating dialyzers used in different medical applications (e.g., hemodialysis). Red blood cell volume lost in a dialyzer is monitored by obtaining blood flowrate measurements and hematocrit measurements at input ports and output ports of the dialyzer. The flowrate and hematocrit measurements are used to determine an accumulation of red cell blood volume in the dialyzer. The measurements may be obtained in a lab environment with an in-vitro blood source or may be obtained in a clinical setting with an in-vivo blood source from a patient.

A new apparatus, system and method to purified produced water and removed valuable metals and minerals is described. The apparatus comprises a device for flowing produced water wellbore from a wellbore to the produced water purification apparatus; at least one device to remove heavy metals from the produced water; at least one brine removal device to remove brine from the produced water. The method comprises steps to use the apparatus and the system comprises a control panel that operates the at least one device for removing heavy metals and at least one sensor in a coordinated manner.

Embodiments described herein relate to methods and systems for dewatering solutions via forward osmosis.

The present invention relates to a process for the preparation of an aqueous solution comprising at least one earth alkali hydrogen carbonate, a process for the mineralization and/or stabilization of water as well as the use of the aqueous solution comprising at least one earth alkali hydrogen carbonate obtained by the process for the mineralization and/or stabilization of water.

Disclosed are methods of treating wastewater using a membrane bioreactor and achieving a target phosphorus concentration for the membrane permeate stream. These methods include the steps of dosing a wastewater stream with a rare earth clarifying agent and passing the dosed wastewater stream through the membrane to obtain a membrane permeate stream with a permeate concentration that is less than the phosphorus concentration of the influent stream. This permeate concentration also can be equal to or less than a target phosphorus concentration. In the methods as disclosed herein, the rare earth clarifying agent can be chloride salts of one or more rare earth elements and in certain embodiments, the rare earth clarifying agent can be CeCl.sub.3 and LaCl.sub.3.