A method is provided for processing wastewater having organics even together with high-concentration ammonia-nitrogen, using an apparatus, comprising a catalyzation tank and a subsequent neutralization tank. Organic ammonia-nitrogen wastewater is introduced into tank for reaction without being pre-adjusted by acidic agent or mixing with other additives. A persulfate oxidant is used to process high-efficiency oxidative degradation for ammonia-nitrogen and toxic organics in wastewater through catalyzing oxidation of ultraviolet activation, tiny-amount-transition-metal catalyzation, or both of them, for simultaneous reductions or complete removals of ammonia-nitrogen and organic carbon contents. After neutralization according to actual needs, the final output is complied with biological treatment conditions, discharged-water quality standards, or recycled-water standards. With the high-efficiency catalyzing oxidation, various toxic organics, aromatics, and heterocyclic compounds are degraded; furthermore, ammonia-nitrogen are converted into non-toxic nitrogen gas and nitrate-nitrogen. Finally, ammonia-nitrogen and nitrate-nitrogen in wastewater can be reduced with efficiency, or even completely removed.

A system for separating a soluble solution includes a first freezer configured to receive a liquid feed stream and a refrigerant stream, and discharge a concentrated solution stream, wherein the first freezer is configured to exchange heat between the liquid feed stream and the refrigerant stream through direct contact within the first freezer and freeze a portion of the liquid feed stream, a first separator external to the first freezer and configured to separate ice particles from the concentrated solution stream and recirculate the concentrated solution stream to the first freezer, and a first ice washer coupled to the first separator and configured to receive the ice particles separated from the concentrated solution stream by the first separator and wash the separated ice particles to free the ice particles from contaminants.

Methods to increase the efficiency and throughput of hydrocarbon stream cracking by inhibiting the formation of, or resolving an emulsion, in an ethylene production quench water system. The method includes contacting a non-alkoxylated branched or linear polyethylenimine (PEI) with a quench water composition from the quench water system under conditions suitable to prevent the formation of an emulsion or to resolve the quench water composition into two immiscible phases.

A membrane sorbent is described, which comprises 1-6 wt % silicon carbide nanoparticles dispersed in a polymer matrix. The polymer matrix may comprise polysulfone and polyvinylpyrrolidone. The membrane sorbent is used for separating oil from a contaminated water mixture. The silicon carbide nanoparticles of the membrane sorbent may be made from rice husk ash.

Described herein is a flow-through application and system that utilizes a nanoparticle technology, which is modular and scalable, that can be utilized to recover a contaminant from water using an attendant pump and in-line sensors along with magnets and ultrasonic energy to separate magnetic nanoparticles from an aqueous mixture and to further separate recovered contaminant from contaminant-adsorbent nanoparticles. The contaminant can include an organic contaminant, such as an oil.

The present invention generally relates to a system and method for treating spent caustic effluent using chlorine dioxide solution. The system comprises a spent caustic storage tank for receiving spent caustic obtained from refinery operations; an acid storage container connected to the spent caustic storage tank for neutralizing free alkali content with a mineral acid to eliminate unwanted chemical reactions associated with free caustic present in spent caustic with ClO.sub.2; a heat exchanger unit engaged for reducing temperature of spent caustic to 35-45 C. from high temperature raised due to heat of neutralisation at least one of a cavitation (mixing) chamber or venturi mixing equipment mechanically connected downstream of the heat exchanger unit for adding ClO.sub.2 solution to the spent caustic solution to oxidize sulphide/thiols content for complete reduction of sulphide/mercaptane and reduction of 80-90% of COD.

The present invention relates to a process for refinery wastewater treatment. More particularly, the present invention relates to an automated process for treatment of refinery wastewater. The process of the present invention provides complete automation for controlling different critical parameters that enhance biological activity of activated sludge process (ASP) and helps in significant reduction in sludge recycling that increases the treatment efficiency.