Arsenic Uptake by Pyrite at Ambient Environmental Conditions: A Continuous-Flow Experiment

Author(s):  
M. Wolthers ◽  
I. B. Butler ◽  
D. Rickard ◽  
P. R. D. Mason
2002 ◽  
Vol 30 (4) ◽  
pp. 696-698 ◽  
Author(s):  
M. G. Wiebe

Fusarium venenatum A3/5 was grown in iron-restricted batch cultures and iron-limited chemostat cultures to determine how environmental conditions affected siderophore production. The specific growth rate in iron-restricted batch cultures was 0.22 h−1, which was reduced to 0.12 h−1 when no iron was added to the culture. Derit in iron-limited chemostat culture was 0.1 h−1. Siderophore production was correlated with specific growth rate, with the highest siderophore production occurring at D = 0.08 h−1 and the lowest at D = 0.03 h−1. Siderophore production was greatest at pH 4.7 and was significantly reduced at pHs above 6.0. Siderophore production could be enhanced by providing insoluble iron instead of soluble iron in continuous flow cultures.


2015 ◽  
Vol 73 (2) ◽  
pp. 267-274 ◽  
Author(s):  
Yupin Phujomjai ◽  
Anchana Somdee ◽  
Theerasak Somdee

Cyanobacterial hepatotoxin microcystins are a health problem found in bodies of water in Thailand. Bacteria capable of biodegrading microcystin [Dha7]MC-LR were isolated from the Bueng Nong Khot reservoir in Khon Kaen, Thailand. The bacterium Novosphingobium isolate KKU25s was shown to degrade [Dha7]MC-LR at a concentration of 25 μg l−1 at 30 °C within 24 h. Two intermediate by-products (linearized peptide and tetrapeptide) and a cluster gene (mlrA, mlrB, mlrC and mlrD) that encodes four putative enzymes involved in [Dha7]MC-LR degradation were detected in KKU25s. KKU25s was also shown to form strong biofilms in microtiter plate assays. These assays were carried out in preparation for use of the bacterium in a bioreactor for [Dha7]MC-LR degradation. In an internal airlift loop bioreactor, the biodegradation of [Dha7]MC-LR by the bacterium was established in batch and continuous flow experiments. In the batch experiment, KKU25s degraded [Dha7]MC-LR at a concentration of 25 μg l−1 at 30 °C within 24 h, whereas in the continuous flow experiment, KKU25s degraded the toxin at the same concentration within 36 h. This study demonstrated that this bacterium could potentially be used to remove microcystins from water.


2020 ◽  
Vol 4 ◽  
pp. 100059
Author(s):  
Hanlu Yan ◽  
Minghan Luo ◽  
Qiuwen Chen ◽  
Taeseop Jeong ◽  
Jianyun Zhang ◽  
...  

2010 ◽  
Vol 4 (1) ◽  
pp. 61-67 ◽  
Author(s):  
Pieter J. Nieuwland ◽  
Kaspar Koch ◽  
Jan C.M. van Hest ◽  
Floris P.J.T. Rutjes

Microreactors have found widespread use for continuous flow synthesis and reaction optimization. Flow rates are critical factors with respect to the latter application because they are used to set screening parameters such as reaction time and stoichiometric ratios. However, the set flow values of pumps for nanoliter to microliter volume reactors are quite often not sufficiently accurate. In this paper we present a generally applicable chromatographic method to analyze flow rates during microreactor reaction screening. By adding flow markers to all reactant and reagent flows and performing conventional GC analysis on all samples, an accurate flow rate was calculated. The deviation between the set flow values and the measured flow rates was shown for a standard continuous flow experiment. The implications of this deviation for reaction optimization were demonstrated via a model Swern-Moffatt oxidation reaction, which showed that accurately measured flow rates are critical for correct data interpretation.


Author(s):  
K. Ohi ◽  
M. Mizuno ◽  
T. Kasai ◽  
Y. Ohkura ◽  
K. Mizuno ◽  
...  

In recent years, with electron microscopes coming into wider use, their installation environments do not necessarily give their performance full play. Their environmental conditions include air-conditioners, magnetic fields, and vibrations. We report a jointly developed entirely new vibration isolator which is effective against the vibrations transmitted from the floor.Conventionally, large-sized vibration isolators which need the digging of a pit have been used. These vibration isolators, however, are large present problems of installation and maintenance because of their large-size.Thus, we intended to make a vibration isolator which1) eliminates the need for changing the installation room2) eliminates the need of maintenance and3) are compact in size and easily installable.


2020 ◽  
Vol 22 (19) ◽  
pp. 6437-6443
Author(s):  
Cheng-Kou Liu ◽  
Meng-Yi Chen ◽  
Xin-Xin Lin ◽  
Zheng Fang ◽  
Kai Guo

A catalyst-, oxidant-, acidic solvent- and quaternary ammonium salt-free electrochemical para-selective hydroxylation of N-arylamides at rt in batch and continuous-flow was developed.


Sign in / Sign up

Export Citation Format

Share Document