Continuous preparation of nanoscale zero-valent iron using impinging stream-rotating packed bed reactor and their application in reduction of nitrobenzene

Nutrients, such as nitrate, nitrite, and phosphorus, are common contaminants in many aquatic systems in the United States. Ammonia and nitrate are both regulated by the drinking water standards in the US primarily because excess levels of nitrate might cause methemoglobinemia. Phosphorus might become sources of the eutrophication problems associated with toxic algae in the freshwater bodies. Toxic algal blooms can cause severe acute and chronic public health problems. Chemical reduction of nitrate by using zero-valent iron started as early as 1964, and considerable research reports relating to this technology to nanomaterial were extensively reported in 1990s making the use of nanoscale zero-valent iron (NZVI) particles for nitrate removal become one of the most popular technologies in this field. The purpose of the present study was to examine the potential of integrating green sorption media, such as sawdust, limestone, tire crumb, and sand/silt, with two types of nanoparticles, including NZVI and Titanium Dioxide ( TiO 2), for nitrate removal in an engineering process. The study consists of running packed bed column tests followed by the addition of NZVI and TiO 2 to improve nitrate and phosphorus removal efficiency. Preliminary results in this paper show that the potential and advanced study may support the creation of design criteria of stormwater and groundwater treatment systems for water reuse in the future.

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Synthesis of nano-fibers of aluminum hydroxide in novel rotating packed bed reactor

Chemical Engineering Science ◽

10.1016/s0009-2509(02)00581-x ◽

2003 ◽

Vol 58 (3-6) ◽

pp. 569-575 ◽

Cited By ~ 90

Author(s):

Jian-Feng Chen ◽

Lei Shao ◽

Fen Guo ◽

Xing-Ming Wang

Keyword(s):

Aluminum Hydroxide ◽

Packed Bed ◽

Packed Bed Reactor ◽

Rotating Packed Bed

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Polymerization of Isobutylene in a Rotating Packed Bed Reactor: Experimental and Modeling Studies

Applied Sciences ◽

10.3390/app112110194 ◽

2021 ◽

Vol 11 (21) ◽

pp. 10194

Author(s):

Wenhui Hou ◽

Wei Wang ◽

Yang Xiang ◽

Yingjiao Li ◽

Guangwen Chu ◽

...

Keyword(s):

Strong Dependence ◽

Average Molecular Weight ◽

Packed Bed ◽

Packed Bed Reactor ◽

Mixing Efficiency ◽

Polymerization Temperature ◽

Analysis Method ◽

Rotating Speed ◽

Rotating Packed Bed ◽

The Given

Polymerization of isobutylene (IB) for synthesizing highly reactive polyisobutylene (HRPIB) is characterized by a complicated fast intrinsic reaction rate; therefore, the features of its products exhibit a strong dependence on mixing efficiency. To provide uniform and efficient mixing, a rotating packed bed was employed as a reactor for polymerization of IB. The effects of operating parameters including polymerization temperature (T), rotating speed (N) and relative dosage of monomers and initiating systems ([M]0/[I]0) on number-average molecular weight (Mn) of HRPIB were studied. HRPIB with Mn of 2550 g·mol−1 and exo-olefin terminal content of 85 mol% were efficiently obtained at suitable conditions as T of 283 K, N of 1600 rpm and [M]0/[I]0 of 49. Moreover, the Mn can be regulated by changing T, N and [M]0/[I]0. Based on the presumptive-steady-state analysis method and the coalescence–redispersion model, a model for prediction of the Mn was developed and validated, and the calculated Mn values agreed well with experimental results, with a deviation of ±10%. The results demonstrate that RPB is a promising reactor for synthesizing HRPIB, and the given model for Mn can be applied for the design of RPB and process optimization.

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