Corrigendum to “Characterization of the nonlinear salinity dependence of glass pH electrodes: A simplified spectrophotometric calibration procedure for potentiometric seawater pH measurements at 25 °C in marine and brackish waters: 0.5 ≤ S ≤ 36” [Marine Chemistry (2020) 103764]

2020 ◽  
Vol 222 ◽  
pp. 103786
Author(s):  
Loraine Martell-Bonet ◽  
Robert H. Byrne
Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2123
Author(s):  
Makuachukwu F. Mbaegbu ◽  
Puspa L. Adhikari ◽  
Ipsita Gupta ◽  
Mathew Rowe

Determining gas compositions from live well fluids on a drilling rig is critical for real time formation evaluation. Development and utilization of a reliable mass spectrometric method to accurately characterize these live well fluids are always challenging due to lack of a robust and effectively selective instrument and procedure. The methods currently utilized need better calibration for the characterization of light hydrocarbons (C1–C6) at lower concentrations. The primary goal of this research is to develop and optimize a powerful and reliable analytical method to characterize live well fluid using a quadruple mass spectrometer (MS). The mass spectrometers currently being used in the field have issues with detection, spectra deconvolution, and quantification of analytes at lower concentrations (10–500 ppm), particularly for the lighter (<30 m/z) hydrocarbons. The objectives of the present study are thus to identify the detection issues, develop and optimize a better method, calibrate and QA/QC the MS, and validate the MS method in lab settings. In this study, we used two mass spectrometers to develop a selective and precise method to quantitatively analyze low level lighter analytes (C1–C6 hydrocarbons) with masses <75 m/z at concentrations 10–500 ppm. Our results suggest that proper mass selection like using base peaks with m/z 15, 26, 41, 43, 73, and 87, respectively, for methane, ethane, propane, butane, pentane, and hexane can help detect and accurately quantify hydrocarbons from gas streams. This optimized method in quadrupole mass spectrometer (QMS) will be invaluable for early characterization of the fluid components from a live hydrocarbon well in the field in real time.


2020 ◽  
Author(s):  
Juan L. Herrera ◽  
Jose González ◽  
Fiz F. Pérez ◽  
Gabriel Rosón ◽  
Ramiro A. Varela

Abstract. Oceanic Acidification is the process that describes a shift in the acid-base equilibrium caused by the rise of the CO2 concentration in the ocean. The project A.RIOS lists among its goals to establish an observation network of oceanic acidification in the Rías and the Galician shelf (NW Iberia). Included in that observation network, an autonomous instrument for spectrophotometric measurements of seawater pH was deployed at the Ría de Vigo during four periods between November 2017 and May 2019. We present here the pH data for those deployments along with temperature, salinity, and pressure data. All the data is available through an unrestricted repository at https://doi.pangaea.de/10.1594/PANGAEA.909933 (Varela et al., 2019). In the author's opinion, this dataset significantly improves the temporal resolution of the pH database in the Ría of Vigo.


2002 ◽  
Vol 2 (2) ◽  
pp. 115-122 ◽  
Author(s):  
A. Adin ◽  
L. Dean ◽  
F. Bonner ◽  
A. Nasser ◽  
Z. Huberman

Inorganic and organic particles, including bacteria, viruses and parasites, which are retained within a granular filter during surface water filtration, are removed by backwashing the filter with clean water or water and air. The objective of the study was to characterize SFBW and determine its treatability by coagulation. Microbial and physical-chemical characterization of SFBW collected from a number of different water treatment plants was performed. Experiments to determine the impact of coagulation/flocculation on the SFBW samples were also conducted. SFBW was collected from six different water treatment plants and analyzed for microbial and physical parameters. Physical characterization was done on SFBW collected from all of the treatment plants. Turbidity and pH measurements were taken over the course of the backwash run, and the backwash samples were collected in two to four 20 L containers. A number of parameters were measured for the samples in each container, as well as for SFBW composites made by mixing equal portions of the container contents. The measured parameters included: turbidity, pH, TSS, DOC, UV-254 and alkalinity. Jar tests were carried out on individual containers, on SFBW composite and on SFBW composite that was allowed to settle for one hour. Turbidity and particle count data was collected for both settled and filtered samples.


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