Increasing the efficiency of the separation and purification process for paclitaxel by pre-treatment with water

2016 ◽  
Vol 51 (10) ◽  
pp. 1738-1743 ◽  
Author(s):  
Chung-Gi Lee ◽  
Jin-Hyun Kim
Keyword(s):  
Purification Process ◽  
Separation And Purification ◽  
Pre Treatment

Treatment of Groundwater with Slow Sand Filtration

1988 ◽  
Vol 20 (3) ◽  
pp. 141-147 ◽  
Author(s):  
T. Hatva
Keyword(s):  
Biological Activities ◽  
Treatment Phase ◽  
Purification Process ◽  
Sand Filtration ◽  
Sand Filters ◽  
Slow Sand Filtration ◽  
Filtration Method ◽  
Pre Treatment ◽  
Full Scale Tests ◽  
Iron Manganese

The purification process and techniques of the slow sand filtration method for treatment of groundwater was studied on the basis of pilot plant and full scale tests and studies of waterworks, to obtain guidelines for construction and maintenance. The purification process consists in general of two principal phases which are pre-treatment and slow sand filtration. Both are biological filters. The main purpose of the pre-treatment is to reduce the iron content of raw water, in order to slow down the clogging of the slow sand filters. Different types of biofilters have proved very effective in the pre-treatment phase, with reduction of total iron from 50 % to over 80 %. During the treatment, the oxidation reduction conditions gradually change becoming suitable for chemical and biological precipitation of iron, manganese and for oxidation of ammonium. Suitable environmental conditions are crucial in the oxidation of manganese and ammonium which, according to these studies, mainly occurs in slow sand filters, at the end of the process. Low water temperature in winter does not seem to prevent the biological activities connected with the removal of iron, manganese and ammonium, the chief properties necessitating treatment of groundwater in Finland.

Stereosequenced crystalline polyhydroxyalkanoates from diastereomeric monomer mixtures

Science ◽  
2019 ◽  
Vol 366 (6466) ◽  
pp. 754-758 ◽  
Author(s):  
Xiaoyan Tang ◽  
Andrea H. Westlie ◽  
Eli M. Watson ◽  
Eugene Y.-X. Chen
Keyword(s):  
Energy Cost ◽  
High Performance ◽  
Polymeric Materials ◽  
Powerful Method ◽  
Purification Process ◽  
Separation And Purification ◽  
Material Loss ◽  
Stereogenic Centers

Stereoselective polymerization of chiral or prochiral monomers is a powerful method to produce high-performance stereoregular crystalline polymeric materials. However, for monomers with two stereogenic centers, it is generally necessary to separate diastereomers before polymerization, resulting in substantial material loss and added energy cost associated with the separation and purification process. Here we report a diastereoselective polymerization methodology enabled by catalysts that directly polymerize mixtures of eight-membered diolide (8DL) monomers with varying starting ratios of chiral racemic (rac) and achiral meso diastereomers into stereosequenced crystalline polyhydroxyalkanoates with isotactic and syndiotactic stereodiblock or stereotapered block microstructures. These polymers show enhanced ductility and toughness relative to polymers of pure rac-8DL, subject to tuning by variation of the diastereomeric ratio and structure of the 8DL monomers.

Silicon separation and purification process from hypereutectic aluminum-silicon for organosilicon use

2021 ◽  
Vol 121 ◽  
pp. 105333
Author(s):  
Yunfei He ◽  
Xi Yang ◽  
Lianfei Duan ◽  
Shaoyuan Li ◽  
Zhengjie Chen ◽  
...  
Keyword(s):  
Purification Process ◽  
Separation And Purification ◽  
Aluminum Silicon

A novel separation and purification process for 1,3-propanediol

2006 ◽  
Vol 41 (3) ◽  
pp. 739-744 ◽  
Author(s):  
Mi-Hae Cho ◽  
Sun Im Joen ◽  
Sang-Hyun Pyo ◽  
Sungyong Mun ◽  
Jin-Hyun Kim
Keyword(s):  
Purification Process ◽  
Separation And Purification

scholarly journals Pengaruh Iradiasi Gamma pada Konversi Biomassa Lignoselulosa Sabut Kelapa Menjadi Bioetanol

2019 ◽  
Vol 3 (2) ◽  
pp. 87
Author(s):  
Harum Azizah Darojati ◽  
Sugili Putra ◽  
Fahril Putera Zulprasetya
Keyword(s):  
Gamma Irradiation ◽  
Treatment Process ◽  
Biomass Conversion ◽  
Treatment Method ◽  
Purification Process ◽  
Lignocellulosic Wastes ◽  
Pre Treatment ◽  
Ssf Process ◽  
Lignocellulosic Biomass Conversion ◽  
Irradiation Process

Sabut kelapa adalah salah satu limbah lignoselulosa yang dapat dikonversikan menjadi bioetanol. Konversi bioetanol pada penelitian ini dilakukan melalui beberapa tahapan yaitu proses pre-treatment, proses Saccharification and Simultaneous Fermentation (SSF), dan proses pemurnian. Proses pre-treatment sebagai proses pemecahan ikatan lignoselulosa menjadi poin utama dalam proses konversi biomassa lignoselulosa. Penelitian ini dilakukan untuk mengetahui pengaruh iradiasi gamma terhadap pemecahan ikatan lignoselulosa pada proses pre-treatment tersebut. Proses iradiasi gamma divariasikan pada dosis sebesar 0 kGy, 100 kGy, 150 kGy, 200 kGy, 250 kGy dan dilanjutkan pre-treatment secara kimia menggunakan NaOH 4%. Kemudian dilanjutkan proses pemurnian setelah proses SSF selama 72 jam. Kadar bioetanol yang diperoleh setelah proses pemurnian diukur menggunakan metode refraktometri dan piknometri. Pada penelitian ini diperoleh kadar bioetanol tertinggi pada dosis iradiasi gamma 200 kGy, yaitu 35,15% untuk metode refraktometri, dan 36,77% untuk metode piknometri. Hasil tersebut jauh lebih tinggi bila dibandingkan dengan kadar bioetanol tanpa iradiasi gamma yaitu 2,45% untuk metode refraktometri, dan 6,92% untuk metode piknometri. Penelitian ini menunjukkan bahwa metode pre-treatment dengan iradiasi gamma dapat menghasilkan kadar bioetanol yang lebih tinggi dibandingkan tanpa menggunakan iradiasi gamma.Coconut husk is one of lignocellulosic wastes that can be converted into bioethanol. Bioethanol conversion in this study was carried out through several stages, namely the pre-treatment process, the Saccharification and Simultaneous Fermentation (SSF) process, and the purification process. The pre-treatment process as the process of breaking lignocellulosic bonds becomes the main point in the process of lignocellulosic biomass conversion. This research was conducted to determine the effect of gamma irradiation to breaking lignocellulosic bonds on the pre-treatment process. Gamma irradiation process was varied in doses of 0 kGy, 100 kGy, 150 kGy, 200 kGy, 250 kGy and continued with chemical pre-treatment using 4% NaOH. Then the purification process was continued after the SSF process for 6 days. Bioethanol levels obtained after the purification process were measured using refractometry and picnometry methods. In this study, the highest levels of bioethanol were obtained at a gamma irradiation dose of 200 kGy, namely 34.93% for the refractometry method, and 26.67% for the picnometry method, respectively. These results are much higher when compared to bioethanol levels without gamma irradiation, which is 2.25% for the refractometry method, and 5.49% for the picnometry method, respectively. This study shows that the pre-treatment method with gamma irradiation can produce higher levels of bioethanol than without using gamma irradiation.

scholarly journals The effect of water pre-treatment with poly-aluminiumchloride on the decomposition of dissolved organic matter in managed aquifer recharge

2020 ◽  
Vol 92 (2) ◽  
pp. 99-110
Author(s):  
Paula Niinikoski-Fußwinkel ◽  
◽  
Lotta Purkamo ◽  
Juha Karhu ◽  
◽  
...  
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Managed Aquifer Recharge ◽  
Aluminium Chloride ◽  
Purification Process ◽  
Aquifer Recharge ◽  
Surface Water Treatment ◽  
Decomposition Of Organic Matter ◽  
Direct Sampling ◽  
Pre Treatment

This study examines the effect of poly-aluminium chloride (PACl) pre-treatment on the biological purification process taking place during managed aquifer recharge (MAR). PACl treatment is used in waste and surface water treatment to remove organic material. PACl can decrease the organic carbon contents of water significantly. However, aluminium is toxic to microbes, which may be detrimental when the PACl treatment is followed by infiltration into an aquifer (MAR). In this study the effect of pre-treatment with PACl on the water purification process in MAR was examined, by using sediment from a MAR site in four test columns. Two columns were filled with PACl-treated water, and the remaining ones with river water without PACl. The residence time of water in the columns was raised from direct sampling gradually to 64 days. Among the parameters monitored were the pH of the water, microbial activity and the decomposition of dissolved organic carbon (DOC). The results showed active decomposition in all columns. Decomposition of organic matter, and the amount of living/active microbial cells, was marginally higher in the untreated water, which could imply a better functioning MAR system. However, this may also be due to higher DOC starting concentration.

scholarly journals Simultaneous Recovery of Zinc and Manganese from Cadmium-Containing Mixed-Battery Leachate by Separation and Purification Process

2019 ◽  
Vol 60 (6) ◽  
pp. 980-987
Author(s):  
Dong Ju Shin ◽  
Sung-Ho Joo ◽  
Dongseok Lee ◽  
Jin-Tae Park ◽  
Dong Joon Min ◽  
...  
Keyword(s):  
Purification Process ◽  
Separation And Purification

EELS characterization of “Smut” layer films on steel surface prepared for chrome plating by anodic etching

1995 ◽  
Vol 53 ◽  
pp. 538-539
Author(s):  
E Y. Wang ◽  
J. T. Cherian ◽  
A. Madsen ◽  
R. M. Fisher
Keyword(s):  
Steel Surface ◽  
Surface Preparation ◽  
Treatment Method ◽  
Chrome Plating ◽  
Transmission Electron ◽  
Alloy Steels ◽  
Pre Treatment ◽  
Hard Chrome ◽  
Electron Energy Loss

Many steel parts are electro-plated with chromium to protect them against corrosion and to improve their wear-resistance. Good adhesion of the chrome plate to the steel surface, which is essential for long term durability of the part, is extremely dependent on surface preparation prior to plating. Recently, McDonnell Douglas developed a new pre-treatment method for chrome plating in which the steel is anodically etched in a sulfuric acid and hydrofluoric acid solution. On carbon steel surfaces, this anodic pre-treatment produces a dark, loosely adhering material that is commonly called the “smut” layer. On stainless steels and nickel alloys, the surface is only darkened by the anodic pre-treatment and little residue is produced. Anodic pre-treatment prior to hard chrome plating results in much better adherence to both carbon and alloy steels.We have characterized the anodic pre-treated steel surface and the resulting “smut” layer using various techniques including electron spectroscopy for chemical analysis (ESCA) on bulk samples and transmission electron microscopy (TEM) and electron energy-loss spectroscopy (EELS) on stripped films.

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