Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Powiadomienia systemowe

Sesja wygasła!
Sesja wygasła!

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: stop manganowy

Sortuj według:

Ogranicz wyniki do:

Degradation of pulp mill wastewater by a heterogeneous Fenton-like catalyst Fe/Mn supported on zeolite

Wang Y., Shia S., Wang C., Fanga S.

Environment Protection Engineering

2018

Vol. 44, nr 2

131--145

A novel heterogeneous catalyst, Fe/Mn supported on NaY zeolite, was effectively applied for treating pulp mill effluents. The results of the wastewater quality analysis showed that aromatic structures were present in raw pulp mill effluents, which indicated the difficulty for biodegradation treatments. Two different catalysts were prepared by impregnation (Fe-Mn/NaYim) and sol-gel (Fe-Mn/NaYsg) methods, respectively. The Fe-Mn/NaYsg catalyst demonstrated higher COD removal efficiency and was more stable than the Fe-Mn/NaYim catalyst. The synergistic effects were found between Fe and Mn for COD removal. The highest COD removal efficiency (75.2%) was yielded with the Fe-Mn/NaYsg catalyst (Fe/Mn molar ratio of 2) with 4 mmol/dm3 of H2O2 and 1.2 g/dm3 of catalyst addition. A constant COD removal over time was obtained; the COD removal efficiency amounted to 45% after the Fe-Mn/NaYsg catalyst repeatedly degrading pulp mill effluents for five times. The distribution and transformation of the polarity and molecular weight (MW) of dissolved organic carbon (DOC) in the heterogeneous Fenton process were also studied. Experiments showed that the hydrophobic fraction comprised the largest fraction of DOC (60%) in raw wastewater and high MW molecules were transformed into low MW molecules after the heterogeneous Fenton process. This study broadened the application of the Fenton technology.

Development of sintered Mn-(Mo)-(Cr)-C steels.

Mitchell S.C., Wronski A.S., Cias A.

Inżynieria Materiałowa

2001

R. XXII, nr 5

633-646

The potential of manganese and chromium as alloying elements, reflected in their widespread use in wrought medium-to-high strength steels, is still to be realised in Powder Metallurgy alloys. The attempts to sinter Mn [+ Cr] alloys have largely ended in failure, due to either poor mechanical properties or lack of reproducibility. The authors have analysed previously published results and identified the principal reason as lack of process control: both in powder preparation and during sintering. This leads to large-scale oxidation, in the form of brittle networks, and also to lack of diffusion, due to the oxide film barriers. Reviewed now are the necessary processing conditions established for the successful processing of manganese steels. The development of additional chromium and molybdenum alloying is also considered and results are presented which additionally incorporate current areas of research, involving warm compaction, high temperature (including liquid phase) sintering and sinter and air hardening.