The processing of PFAS to convert them into safer substances comprises introducing gaseous or vapour phase PFAS into a treatment zone where microwave radiation of predetermined frequency and power level creates a plasma which at least partially dissociates the PFAS. There is also a system for remediating particulate solids, particularly soil, contaminated with PFAS, the method including directing microwave radiation to a body of particulate solids in the closed vessel so as to promote vaporization of PFAS which are then treated by exposure to the microwave produced plasma. Continuous and batch processing apparatus are disclosed. A preheating stage can dry the particulate solids to a pre-determined moisture content, and then a higher energy microwave heating promotes vaporization of PFAS. A partial vacuum created where particulate solids heated by the microwave radiation are yielding up PFAS promotes the vaporization of PFAS. Alternating cycles of high pressure during microwave irradiation and low pressure or partial vacuum can avoid plasma generation in the heating stage while optimizing vaporization of PFAS from the particulate solids.

The processing of PFAS to convert them into safer substances comprises introducing gaseous or vapour phase PFAS into a treatment zone where microwave radiation of predetermined frequency and power level creates a plasma which at least partially dissociates the PFAS. There is also a system for remediating particulate solids, particularly soil, contaminated with PFAS, the method including directing microwave radiation to a body of particulate solids in the closed vessel so as to promote vaporization of PFAS which are then treated by exposure to the microwave produced plasma. Continuous and batch processing apparatus are disclosed. A preheating stage can dry the particulate solids to a pre-determined moisture content, and then a higher energy microwave heating promotes vaporization of PFAS. A partial vacuum created where particulate solids heated by the microwave radiation are yielding up PFAS promotes the vaporization of PFAS. Alternating cycles of high pressure during microwave irradiation and low pressure or partial vacuum can avoid plasma generation in the heating stage while optimizing vaporization of PFAS from the particulate solids.

A catalyst for inducing thermal desorption of organic matter-contaminated soil and a preparation method thereof, which uses a colloidal mixture of ferroferric oxide and ferric chloride as a catalytic active component of thermal desorption, and carbon tetrachloride as a solvent. Based on the mass of solvent, a mass percentage of catalytic active component is 0.1%-15%. Ammonia water is added dropwise to ferric chloride aqueous solution to react in oil bath to generate a ferroferric oxide colloidal solution, then ferric chloride and obtained ferroferric oxide colloidal solution are added to carbon tetrachloride, and mixed solution is continuously stirred in an oil bath to evaporate solvent water to prepare a catalyst with carbon tetrachloride as solvent. Catalyst is environmentally friendly and can induce thermal desorption of organic matters in soil. 100% desorption of chlorobenzene, o-xylene and benzo[A]anthracene can be achieved at 130° C., and energy consumption of thermal desorption is greatly reduced.

A catalyst for inducing thermal desorption of organic matter-contaminated soil and a preparation method thereof, which uses a colloidal mixture of ferroferric oxide and ferric chloride as a catalytic active component of thermal desorption, and carbon tetrachloride as a solvent. Based on the mass of solvent, a mass percentage of catalytic active component is 0.1%-15%. Ammonia water is added dropwise to ferric chloride aqueous solution to react in oil bath to generate a ferroferric oxide colloidal solution, then ferric chloride and obtained ferroferric oxide colloidal solution are added to carbon tetrachloride, and mixed solution is continuously stirred in an oil bath to evaporate solvent water to prepare a catalyst with carbon tetrachloride as solvent. Catalyst is environmentally friendly and can induce thermal desorption of organic matters in soil. 100% desorption of chlorobenzene, o-xylene and benzo[A]anthracene can be achieved at 130° C., and energy consumption of thermal desorption is greatly reduced.

Methods and systems are provided for two-stage treatment of contaminated particulate material, such as soil, sediment, and/or sludge. The methods and systems utilize a thermal desorption process combined with a smoldering combustion process. The contaminated particulate material is first exposed to thermal desorption at high temperatures (e.g., greater than 150° C.) to form a heated contaminated particulate material. Next, a smoldering combustion process is initiated by introducing a combustion-supporting gas. The combined process can take place in the same or different treatment units. Treating the particulate material with a thermal desorption process prior to a smoldering combustion process enhances the completeness and throughput compared to operating these processes separately.

Methods and systems are provided for two-stage treatment of contaminated particulate material, such as soil, sediment, and/or sludge. The methods and systems utilize a thermal desorption process combined with a smoldering combustion process. The contaminated particulate material is first exposed to thermal desorption at high temperatures (e.g., greater than 150° C.) to form a heated contaminated particulate material. Next, a smoldering combustion process is initiated by introducing a combustion-supporting gas. The combined process can take place in the same or different treatment units. Treating the particulate material with a thermal desorption process prior to a smoldering combustion process enhances the completeness and throughput compared to operating these processes separately.

The present application relates to a novel method for reductive degradation of perfluoroalkyl-containing compounds, such as perfluoroalkyl sulfonates, by activated carbon (AC) supported zero valent iron-nickle nanoparticles (nNi.sup.0Fe.sup.0).

The present application relates to a novel method for reductive degradation of perfluoroalkyl-containing compounds, such as perfluoroalkyl sulfonates, by activated carbon (AC) supported zero valent iron-nickle nanoparticles (nNi.sup.0Fe.sup.0).

A hot air circulation type indirect thermal desorption-based soil remediation system and method, belonging to the technical field of soil remediation. The system includes a thermal desorption reactor, a dust remover, a hot air circulating fan, a hot air heater, an air preheater, a combustion fan and a combustion device. By using thermal desorption gas generated by soil being heated and volatilized as a heat transfer medium and by a circular heating manner, hot air efficiently transfers heat to the soil by contact, and the high-temperature fume is kept from direct contact with the soil, so the system has the advantages of high treatment capacity, small equipment scale and the like.

An in-situ vapor injection thermal desorption device includes a sectional combined input head, several intermediate connectors and a bottom protector connected in series from top to bottom. The in-situ vapor injection thermal desorption device further includes several water-vapor coupling injection activation chips, selectively disposed below any of the intermediate connectors; the sectional combined input head is provided with a high-pressure-gas inlet, several pairs of heat-transfer-oil inlets and heat-transfer-oil outlets, and several pairs of hot-water inlets and hot-water outlets; the water-vapor coupling injection activation chip is provided with several gas-liquid spraying holes. The disclosure is an assembling structure; the number of the water-vapor coupling injection activation chips can be increased or reduced according to remediation depth on an actual site; it can be repeatedly used, uniformly sprayed, and enables the vapor for treating the organic soil to be generated in situ and remediating organic pollution sites in a low-carbon, energy-saving way.