Sampling concept for microplastics in combined sewage-affected freshwater and freshwater sediments

2020 ◽  
Vol 194 (1) ◽  
pp. 37-48 ◽  
Author(s):  
Simone Lechthaler ◽  
Regina Dolny ◽  
Vanessa Spelthahn ◽  
Johannes Pinnekamp ◽  
Volker Linnemann
Keyword(s):  
Stainless Steel ◽  
Sampling Method ◽  
Treatment Process ◽  
Mesh Size ◽  
Freshwater Sediments ◽  
Size Fractions ◽  
Filter Disc ◽  
General Method

The pollution of the environment with microplastics is an issue of great concern, with research of this topic focusing on the sampling and analysis of microplastics. As the sampling method is connected to the matrices from which the samples are collected, there is no general method for the analysis of microplastics, neither in water nor in sediments and, especially, there is no existing method for combined sewage. To obtain comparable results of samples from different matrices, we present a concept based on samples taken from combined sewage, combined sewage-affected freshwater, and freshwater sediments, which were prepared analogously in a treatment process to establish an equivalent starting sample for further analysis. The concept is based on a filter disc (stainless-steel, 47- mm diameter, 20-μm mesh size) for sampling the different water and sediments. With this filter disc, the removal of organic and anorganic matrices was conducted and then used to generate subsamples of different size fractions, which are identical for all samples and complete the sampling concept.

Precipitation Behavior of a Maraging Stainless Steel

2012 ◽  
Vol 567 ◽  
pp. 92-95 ◽  
Author(s):  
Yue Jiang ◽  
Ying Ying Ai ◽  
Qi Ting Wang
Keyword(s):  
Stainless Steel ◽  
Treatment Process ◽  
Aging Treatment ◽  
Heat Treatment Process ◽  
New Materials ◽  
Precipitation Behavior ◽  
Thermo Calc Software ◽  
Calculation Results ◽  
Maraging Stainless Steel ◽  
Good Agreement

The changes of precipitation phases and matrix structures in Fe-13Cr-7Ni-4Mo-4Co-2W maraging stainless steel at different temperature were studied by using the Thermo-Calc software. The research was on the microstructures and precipitation behaviors of the maraging stainless steel, the performance is investigated through solution and aging treatment by TEMand SADP. The calculation results were in good agreement with the experiments, which demonstrated that when maraging stainless steel was treated in high temperature, the Laves-Fe2Mo precipitates became totally dissolved as the temperature was above 1050°C, and about 8% of R phase was found during aging. The calculation provides a guiding significant to the establishment of reasonable heat treatment process and the development of new materials.

Electrophoretic Deposition of PEEK-TiO2 Composite Coatings on Stainless Steel

2012 ◽  
Vol 507 ◽  
pp. 127-133 ◽  
Author(s):  
Sigrid Seuss ◽  
Tayyab Subhani ◽  
Min Yi Kang ◽  
Kenji Okudaira ◽  
Isaac E. Aguilar Ventura ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Stainless Steel ◽  
Electrophoretic Deposition ◽  
Biomedical Applications ◽  
316L Stainless Steel ◽  
Treatment Process ◽  
Composite Coatings ◽  
Heat Treatment Process ◽  
Steel Substrates ◽  
Scanning Electron

Electrophoretic deposition (EPD) has been successfully used to deposit composite coatings composed of polyetheretherketone (PEEK) and titanium dioxide (TiO2) nanoparticles on 316L stainless steel substrates. The suspensions of TiO2 nanoparticles and PEEK microparticles for EPD were prepared in ethanol. PEEK-TiO2 composite coatings were optimized using suspensions containing 6wt% PEEK-TiO2 in ethanol with a 3:1 ratio of PEEK to TiO2 in weight and by applying a potential difference of 30 V for 1 minute. A heat-treatment process of the optimized PEEK-TiO2 composite coatings was performed at 335°C for 30 minutes with a heating rate of 10°Cminto densify the deposits. The EPD coatings were microstructurally evaluated by scanning electron microscopy (SEM). It was demonstrated that EPD is a convenient and rapid method to fabricate PEEK/TiO2 coatings on stainless steel which are interesting for biomedical applications.

Assessing Corrosion of UNS S30403 Stainless Steel for Applications in Nuclear Waste Reprocessing Systems

CORROSION ◽  
10.5006/0747 ◽  
2013 ◽  
Vol 69 (6) ◽  
pp. 568-579
Author(s):  
N. Jahangiri ◽  
A.G. Raraz ◽  
J.E. Indacochea ◽  
S.M. McDeavitt
Keyword(s):  
Stainless Steel ◽  
Nuclear Waste ◽  
Treatment Process ◽  
Spent Nuclear Fuel ◽  
Acidic Solution ◽  
Electrochemical Impedance ◽  
Corrosive Environment ◽  
Hydrodynamic Conditions ◽  
Corrosion Rates ◽  
Centrifugal Contactors

To investigate the corrosion of centrifugal contactors in the spent nuclear fuel treatment process called UREX+, corrosion of UNS S30403 stainless steel has been studied in three acidic aqueous solutions of 5.0 M nitric acid (HNO3), 5.0 M HNO3 + 0.1 M hydrofluroric acid (HF), and 5.0 M HNO3 + 0.1 M HF + 0.1 M Zr4+. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) tests were conducted at temperatures of 25, 40, and 80°C and different hydrodynamic conditions (0, 1,000, 2,000 rpm). The results showed that the mixture of HNO3 and HF was the most corrosive environment. Addition of Zr4+ ions to this acidic solution reduced the corrosion caused by HF to levels similar to those found in HNO3 solutions. Higher corrosion rates were obtained as the solution's temperature increased while hydrodynamic conditions had a less significant effect on corrosion rates.

scholarly journals ASPEK REPRODUKSI IKAN WADER IJO (OSTHEOCHILUS HASSELTI) DI DANAU RAWAPENING AMBARAWA, KABUPATEN SEMARANG

2018 ◽  
Vol 6 (1) ◽  
pp. 77-86
Author(s):  
Muhammad Rizky Nugraha ◽  
Anhar Solichin ◽  
Boedi Hendrarto
Keyword(s):  
Sampling Method ◽  
Average Length ◽  
Gonadosomatic Index ◽  
Mesh Size ◽  
Chi Square ◽  
Gill Net ◽  
Level Ii ◽  
Mature Fish ◽  
First Maturity ◽  
Egg Diameter

ABSTRAK Ikan Wader Ijo (O. hasselti) merupakan ikan khas di Danau Rawapening.  Populasinya saat ini diduga mengalami penurunan, akibat penangkapan ikan Wader Ijo yang sedang bertelur dan penggunaan alat tangkap dengan mesh size kecil. Penelitian ini bertujuan untuk mengetahui aspek reproduksi ikan Wader Ijo, faktor lingkungan dan mesh size gill net yang aman digunakan. Penelitian yang dilakukan bersifat deskriptif, dengan teknik pengambilan sampel acak. Penelitian dilaksanakan Juli - Agustus 2016 di Danau Rawapening. Sampel diperoleh 93 ekor menggunakan gill net mesh size 2 inchi, dengan panjang total 111 – 210 mm. Nisbah kelamin 1:6,75 dengan dominasi ikan betina. Sampel didominasi ikan matang gonad pada TKG IV. Berdasarkan analisa PCA, Ikan Wader Ijo pada TKG II, III dan IV memiliki korelasi negatif dengan pH, arus dan oksigen terlarut. Angka Indeks Kematangan Gonad tertinggi betina diperoleh 30,30%, sedangkan jantan 19,67%. Ikan Wader Ijo yang tertangkap belum mengalami recruitment overfishing karena ukuran ikan pertama kali matang gonad jantan 100,63 mm dan betina 110,90 mm lebih kecil dari ukuran rata-rata yang tertangkap153 mm. Fekunditas diperoleh 80.862 – 19.880 butir/individu. Berdasarkan analisa Regresi Power, fekunditas Wader Ijo dipengaruhi oleh panjang tubuhnya. Diameter telur yang diperoleh berkisar 0,01 – 1,01 mm. Berdasarkan analisa Chi-Square, bagian yang berbeda dalam ovarium memiliki hubungan dengan ukuran diameter telur. Mesh size gill net yang aman digunakan minimal berukuran 1,54 inchi. Kata Kunci : Wader Ijo; Aspek Reproduksi;  Rawapening ABSTRACT Bonylip Barb (O. hasselti) is a local fish in Rawapening lake which population of this species in Rawapening already decrease, because of exploitation spawning Bonylip Barb and the used of fishing gear with small mesh size. This research aimed to know reproduction aspects of Bonylip Barb, environmental factors and mesh size of gill net. The method used in this research was descriptive with random sampling method. A total of 93 specimens were collected by gill net mesh size 2 inch from July to August 2016 at Rawapening. Specimens have total lenght 111 – 210 mm. Sex ratio was 1 : 6,75 dominated by female. Gonadal stage dominated by mature fish on level IV. Based on PCA analysis, gonadal stage level II, III and IV have negative correlations with pH, current and dissolved oxygen. The highest Gonadosomatic Index on female was 30,30%, while the male one was 19,67%. Length of first maturity not only male 100,63 mm but also female 110,90 mm smaller than average length of capture 155 mm, it means that Bonylip Barb in Rawapening still safe from recruitment overfishing. Fecundity ranged from 80.862 to 19.880 granules/individual. Based on power regression, fecundity was determined by the total length. Egg diameter ranged from 0,1 to 1,01 mm. Based on Chi-Square, different path of ovary have a corelation  with  egg diameter. Mesh size gill net that used in Rawapening was not recommended under 1,54 inch. Keywords: Bonylip Barb, Reproduction Aspect, Rawapening 

Treatment adherence and related factors among patients in the unique MMT private clinic in Vietnam in 2018

2021 ◽  
Vol 31 (4) ◽  
pp. 85-91
Author(s):  
Le Anh Tuan ◽  
Bui Thanh Thuy ◽  
Nguyen Thi Minh Thuy ◽  
Pham Thi Thu Huyen ◽  
Kieu Thi Hoa ◽  
...  
Keyword(s):  
Treatment Adherence ◽  
Illicit Drugs ◽  
Sampling Method ◽  
Treatment Process ◽  
Cross Sectional Study ◽  
Private Clinic ◽  
Related Factors ◽  
Cross Sectional ◽  
Methadone Clinic ◽  
Process Level

A cross-sectional study using the take-all sampling method was conducted among patients in the unique MMT private clinic in Vietnam in 2018. The study aimed to describe treatment adherence status and related factors of the patients. Data on socioeconomic characteristics, behaviours, treatment process, level of social/family support were collected and analyzed. The results showed that 88.2% of MMT patients completely adhere to the treatment program. Factors positively related to treatment adherence of MMT patients were living with spouse/partner (OR = 3.02 95% CI: 1.11 – 8.19), not using illicit drugs during MMT treatment (OR = 5.88; 95% CI: 1.77 – 19.56). The methadone clinic should pay attention to the factors positively related to treatment adherence in the counselling and support process for the patients.

MARAPUR—a new process combination for the optimization of MBR

2008 ◽  
Vol 58 (11) ◽  
pp. 2101-2107
Author(s):  
F. Klegraf ◽  
J. Lahnsteiner
Keyword(s):  
Wastewater Treatment ◽  
Treatment Process ◽  
Cross Flow ◽  
Mesh Size ◽  
Main Process ◽  
Biological Wastewater Treatment ◽  
Wastewater Treatment Process ◽  
Effective Measure ◽  
New Process ◽  
Process Combination

The MARAPUR concept is a biological wastewater treatment process based on the MBR functional principle. The ultrafiltration of activated sludge takes place in pressure-driven hollow fiber membranes. The vertical membrane modules are installed compactly in a MEGAMODUL. The permeate extraction is accomplished in the cross-flow, which is supported by rinsing aeration. The main process advantages are high filtration performance, excellent operation reliability provided by wastewater fine sieving and reduced cleaning chemicals demand. Wastewater fine sieving with a mesh size of 0.25 mm is an effective measure against membrane clogging by hair and fibers.

Cryogenic Treatment of 06Cr19Ni10 Austenitic Stainless Steel

2013 ◽  
Vol 749 ◽  
pp. 187-191 ◽  
Author(s):  
Hong Zhang ◽  
Kai Xuan Gu ◽  
Jia Guo ◽  
Xiao Dai Xue ◽  
Jun Jie Wang
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Austenitic Stainless Steel ◽  
Room Temperature ◽  
Treatment Process ◽  
Cryogenic Treatment

The effect of cryogenic treatment on mechanical properties and wear resistance at room temperature of 06Cr19Ni10 austenitic stainless steel was studied in the present study. The cryogenic treatment process was carried out at-160 and different time in program-controlled cryogenic container. The results showed that, after cryogenic treatment, the room-temperature mechanical properties of the 06Cr19Ni10 steel remained stable without embrittlement, friction coefficient of the 06Cr19Ni10 steel decreased and the wear resistance improved after cryogenic treatment. When cryogenic treatment was treated at-160 for two hours and thirty minutes, the friction coefficient of the 06Cr19Ni10 steel was the smallest and wear resistance was the best.

Surface Modification of 2205 Duplex Stainless Steel by Low Temperature Thermochemical Hybrid Heat Treatment at 450° C

2013 ◽  
Vol 845 ◽  
pp. 408-411
Author(s):  
M.S. Adenan ◽  
M.N. Berhan ◽  
E. Haruman
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Low Temperature ◽  
Duplex Stainless Steel ◽  
Treatment Process ◽  
Surface Hardness ◽  
Horizontal Tube ◽  
Holding Time ◽  
Hardness Profile ◽  
Heat Treatment Process

An approach has been made in developing hybrid heat treatment process for improvement of surface properties of duplex stainless steel (DSS). The process was performed using horizontal tube furnace at temperature of 450° C at holding time of 4, 8, 16 and 30 hours. Carbon and nitrogen elements were simultaneously introduced onto the surface of DSS with a ratio of 5% CH4 + 25% NH3 + 70% N2. The microstructure, phase analysis, surface hardness and hardness profile were systematically assessed. Hybrid heat treatment process managed to produce diffusional layer, where longer holding time had increased the thickness of the layer and improved the surface hardness. Expanded austenite phase has been formed at specimens 8, 16 and 30 hours. Longer holding time however gradually diffused Cr2N at the ferrite grains at the substrates. From the process, it can be concluded that low temperature hybrid heat treatment be able to improve the surface hardness of DSS however concern on holding time must be highly considered.

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