Removal of boron, fluoride and nitrate by electrodialysis in the presence of organic matter

Banasiak, Laura; Schäfer, A.I.

doi:10.1016/j.memsci.2009.02.020

Cited by 198 publications

(79 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is because the spacing of the (200) plane was reduced by the photocatalytic reduction from NO3 − to NO2 − , the ionic radii of which were ca. 0.20 and 0.16 nm, respectively [21,22]. The island-like deposits as seen in the SEM image ( Fig.…”

Section: Microscopic Morphology Of the Sample Surfacementioning

confidence: 90%

Formation of ZnO thin films by photocatalytic reaction

Nishikiori

Nagaya

Takikawa

et al. 2014

Applied Catalysis B: Environmental

View full text Add to dashboard Cite

Zinc oxide and layered zinc hydroxides were deposited from an aqueous solution of zinc nitrate at 323−358 K on a substrate plate with a very thin titanium dioxide film by a photocatalytic reaction. The amorphous or low crystalline zinc hydroxide aggregates were deposited at a low temperature. The zinc oxide crystals with about 1−2 μm-sized hexagonal columns and 10 nm-sized spheres were formed at 338−358 K. Nitrate ions in the solution were reduced to nitrite ions, and water was transformed into hydroxide ions by a photocatalytic reaction on the titanium dioxide film. The pH value increased on the substrate surface with the titanium dioxide film, which caused the zinc hydroxide formation on the film.The zinc hydroxides were then dehydrated and transformed into zinc oxide. The average crystallite size of the zinc oxide decreased with an increase in the reaction temperature because the reaction rates of the formation and dehydration of the zinc hydroxides increased which resulted in an increase in the formation rate of the crystal zinc oxide nuclei.

show abstract

Section: Microscopic Morphology Of the Sample Surfacementioning

confidence: 90%

Formation of ZnO thin films by photocatalytic reaction

Nishikiori

Nagaya

Takikawa

et al. 2014

Applied Catalysis B: Environmental

View full text Add to dashboard Cite

show abstract

“…In general, high removals of metals are achieved by this process although membrane type affects metal removal [46,134,8,130,9]. Metal speciation plays an important role.…”

Section: Electrodialysismentioning

confidence: 99%

Xenobiotics Removal by Membrane Technology: An Overview

Semiao

Schäfer

2009

Environmental Pollution

Self Cite

View full text Add to dashboard Cite

Small molecular weight xenobiotics are compounds of extreme concern in potable water applications due to their adverse human health and environmental effects. However, conventional water treatment processes cannot fully and systematically remove them due to their low concentrations in natural waters and wastewaters. Biological limitation to degrade such compounds is another cause for inefficient removal.Physical barriers like membranes possessing pore sizes smaller than the compounds to be removed emerged as a good solution. Nanofiltration and reverse osmosis proved to be quite effective for xenobiotics removal in potable water production in the Paris purification plant of Méry-sur-Oise. However, even these very narrow pore membrane processes may result in incomplete removal: xenobiotics retention is high but factors such as adsorption, size exclusion and charge repulsion affect unpredictably their retention. The water solutions complexity to be treated renders xenobiotics removal predictions even more difficult due to interactions between xenobiotics and compounds in water.Removal of xenobiotics by microfiltration and ultrafiltration is very low because adsorption on the membrane is the main retention mechanism. Combining those with other processes (e.g. activated carbon) can considerably improve xenobiotics removal.The least studied processes in xenobiotics removal are electrodialysis, membrane distillation and pervaporation. Electrodialysis removal of organic xenobiotics shows a breakthrough through the membrane possibly due to adsorption followed by diffusion. Membrane distillation presents high removal rates of xenobiotics due to the compounds low vapour pressure. For volatile organic xenobiotics or solutions of trace amounts both membrane distillation and pervaporation can be used, xenobiotics interaction with the membrane being the key factor.In this book chapter a thorough synopsis of current knowledge on xenobiotics removal is presented and balanced with recent fundamental studies of underlying mechanisms, informing both the practitioner regarding membrane capabilities for xenobiotics removal and the researcher with the current state-of-art.

show abstract

“…It has been observed that humic acid particles, which are negatively charged in neutral pH, can be responsible for fouling phenomenon during electrodialysis. Usually, organic matter particles are predominantly deposited on anion-exchange membranes [17].…”

Section: Introductionmentioning

confidence: 99%

“…al [17] did research into fluoride removal with the use of ED in the presence of organic matter. They examined the influence of various organic matter substances (humic acids, HAs; tannic acids, TAs; alginic acid, AAs) on defluoridation efficiency.…”

Section: Introductionmentioning

confidence: 99%