Qingsong Liu

To analyze the decomposition of siderite during thermal treatment, and to characterize the magnetic minerals formed as its alteration products, low‐temperature magnetic measurements were conducted on natural siderite samples that were heated to different temperatures. For the unheated siderite sample, on warming curves remanence sharply decreases at 35–40 K while the in‐phase AC susceptibility peaks, consistent with the Néel temperature ( T N ) at 38 K. The natural siderite can decompose significantly even at relatively low temperature (below 250°C). At this stage, the alteration products are hematite and probably superparamagnetic (SP) maghemite due to the quick oxidization. After 400°C, both susceptibility and SIRM of the thermally treated samples sharply increase, indicating the formation of significant amounts of strongly magnetic minerals. Furthermore, the apparently depressed Verwey transitions at 120 K indicate that most of the ferrimagnetic minerals formed by 490–530°C are either very fine grains or highly oxidized magnetite and/or maghemite.

Maghemite

Ferrimagnetism

Superparamagnetism

10.1029/2002gl016021

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Citations (24)

Regeneration of 4-Chlorophenol Exhausted GAC with a Microwave Assisted Wet Peroxide Oxidation Process

Separation Science and Technology (2013)

Qingsong Liu Tong Zheng Peng Wang Yijing Li

To improve the performance of wet oxidation for the regeneration of GAC, a microwave assisted wet peroxide oxidation process has been applied for the regeneration of 4-chlorophenol exhausted GAC. The effects of various factors including reaction temperature, H2O2 dosage, reaction time, and addition of catalyst have been studied. The regeneration improves with the increase in reaction temperature, H2O2 dosage, and reaction time. The addition of Cu2+ further promotes the regeneration process. Under the conditions of temperature 150°C, H2O2 dosage 15 mmol, reaction time 20 min, Cu2+ concentration 20 mg/L, the regenerated GAC recovers 93.5% of its adsorption capacity. A nearly complete degradation of 4-chlorophenol in the aqueous phase is observed based on UV-vis and high-performance liquid chromatography spectra studies.

Peroxide

Degradation

Oxidation process

10.1080/01496395.2013.809760

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Citations (7)

Co-pyrolysis of iron-rich sewage sludge and potassium phosphate to prepare biochars: P fractionation and alleviated occlusion

Journal of Analytical and Applied Pyrolysis (2021)

Qingsong Liu Tian Tian

Sewage sludge

Potassium phosphate

Iron phosphate