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Author(s):  
Anna Norén ◽  
Célia Lointier ◽  
Oskar Modin ◽  
Ann-Margret Strömvall ◽  
Sebastien Rauch ◽  
...  

AbstractMetal and tributyltin (TBT) contaminated sediments are problematic for sediment managers and the environment. This study is the first to compare Fenton’s reagent and electrochemical treatment as remediation methods for the removal of TBT and metals using laboratory-scale experiments on contaminated dredged sediment. The costs and the applicability of the developed methods were also compared and discussed. Both methods removed > 98% TBT from TBT-spiked sediment samples, while Fenton’s reagent removed 64% of the TBT and electrolysis 58% of the TBT from non-spiked samples. TBT in water phase was effectively degraded in both experiments on spiked water and in leachates during the treatment of the sediment. Positive correlations were observed between TBT removal and the added amount of hydrogen peroxide and current density. Both methods removed metals from the sediment, but Fenton’s reagent was identified as the most potent option for effective removal of both metals and TBT, especially from highly metal-contaminated sediment. However, due to risks associated with the required chemicals and low pH level in the sediment residue following the Fenton treatment, electrochemical treatment could be a more sustainable option for treating larger quantities of contaminated sediment.


Cells ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 151
Author(s):  
Alexander Martens ◽  
Nicole de Buhr ◽  
Hiroshi Ishikawa ◽  
Horst Schroten ◽  
Maren von Köckritz-Blickwede

The host–pathogen interaction during meningitis can be investigated with blood-cerebrospinal-fluid-barrier (BCSFB) cell culture models. They are commonly handled under atmospheric oxygen conditions (19–21% O2), although the physiological oxygen conditions are significantly lower in cerebrospinal fluid (CSF) (7–8% O2). We aimed to characterize oxygen levels in a Streptococcus (S.) suis-infected BCSFB model with transmigrating neutrophils. A BCSFB model with human choroid plexus epithelial cells growing on transwell-filters was used. The upper “blood”-compartment was infected and blood-derived neutrophils were added. S. suis and neutrophils transmigrated through the BCSFB into the “CSF”-compartment. Here, oxygen and pH values were determined with the non-invasive SensorDish® reader. Slight orbital shaking improved the luminescence-based measurement technique for detecting free oxygen. In the non-infected BCSFB model, an oxygen value of 7% O2 was determined. However, with S. suis and transmigrating neutrophils, the oxygen value significantly decreased to 2% O2. The pH level decreased slightly in all groups. In conclusion, we characterized oxygen levels in the BCSFB model and demonstrated the oxygen consumption by cells and bacteria. Oxygen values in the non-infected BCSFB model are comparable to in vivo values determined in pigs in the CSF. Infection and transmigrating neutrophils decrease the oxygen value to lower values.


2021 ◽  
Vol 37 (6) ◽  
pp. 648-658
Author(s):  
Ji Won Kim ◽  
Se Rin Park ◽  
Ki Ok Han ◽  
Seon Hwa Jeong

In this study, we aimed to analyze the chemical changes that occur in Korean paper in an accelerated deterioration environment of 105℃. We selected the Korean paper produced with different types of cooking agents (plant lye, Na2CO3) and during different manufacturing seasons (winter, summer). The degree of deterioration of the Korean paper was confirmed by measuring the brightness, yellowness, and pH level, and the degree of change in each vibrational region of cellulose as deterioration progressed through infrared (FT-IR) spectroscopy. The FT-IR analysis showed that, as deterioration progressed, the absorbance of the amorphous region in cellulose decreased, whereas the absorbance of the crystalline region slightly increased. X-Ray diffraction (XRD) analysis and Raman spectroscopy were performed to verify the changes in the crystalline and amorphous regions in cellulose indicated by the FT-IR results. Furthermore, the crystallinity index (CI) was calculated; it showed a slight increase after deterioration; therefore, CI was confirmed to follow the same trend as that observed for absorbance in the FT-IR results. In addition, as a result of Raman spectroscopic analysis, the degree of decomposition of the amorphous region in the cellulose under the manufacturing conditions was confirmed by the fluorescence measured after the deterioration.


2021 ◽  
Vol 10 (2) ◽  
Author(s):  
Kemas Ridhuan ◽  
Tri Cahyo Wahyudi ◽  
Danang Sulistiyo ◽  
Bahtera Anggara

Distillation of liquid smoke is a process of heating liquid smoke based on the difference in its boiling point and then cooled to get liquid smoke with better quality. This heating aims to separate unwanted components in liquid smoke such as tar and benzopyrene. The process is strongly influenced by several things such as temperature and distillator. From these two measurements, several characteristics such as heating rate, distillation flow rate of liquid smoke, production capacity, heating temperature, steam temperature and distillation time, as well as the characteristics of the resulting liquid smoke can be known.The purpose of this study is to determine the characteristics of the 3rd grade liquid smoke distillation process with electric heating and water cooling condenser which includes the production capacity of liquid smoke and to determine the quality and quantity of liquid smoke, heating rate, electricity consumption, flow rate and to determine the efficiency of 2nd grade liquid smoke production.This research was conducted at the Laboratorium Teknik Mesin Universitas Muhammadiyah Metro, this study used a distillation apparatus made of Aluminium plate 1 mm thick, 180 mm in diameter, 250 mm high. Condenser with 0.5 inch diameter copper pipe 3,5 m long, 3 inch diameter PVC pipe, 3m long. The raw material for 3rd grade liquid smoke is 3 liters.The results obtained that the distillation apparatus has a capacity of 3 liters, the distillation temperature affects the rate of heating that occurs, namely the distillation temperature of 110oC, the heating rate is 707,42 J/second, the electricity consumption is 4,48kWh, the time is 45 minutes, and for a temperature of 120 oC the heating rate is 754,60 J/second, electricity consumption is 4,467 kWh in 65 minutes. The highest yield of liquid smoke is at a temperature of 110 oC, which is 2840 ml with a flow rate of 8,35 ml/minute and an efficiency of 94,6%, pH level of 2,15. And for a temperature of 120 oC it produces 2560 ml of liquid smoke, with a flow rate of 8,67 ml/minute and an efficiency of 85,3%, with a pH level of 2,10.


2021 ◽  
Vol 16 (2) ◽  
pp. 177-189
Author(s):  
Aira Syazleen Ahmad ◽  
Nor Azlida Mohd Nor ◽  
Nadia Afiqah Ahmad ◽  
Zamros Yuzadi Mohd Yusof ◽  
Ivor G. Chestnutt

This study aimed to determine the fluoride and pH levels of beverages likely to be consumed by children in Malaysia and to estimate daily fluoride intake from consumption of these beverages. A convenience sampling of 120 ready-to-drink beverages were purchased and categorised into 11 groups (UHT recombined milk, fresh milk [pasteurised], cultured milk [probiotic], yogurt beverages, fresh fruit juices, fruit flavoured beverages, soy-based beverages, malt-based beverages, tea, carbonated beverages and bottled waters). Fluoride concentration was measured using a fluoride ion-selective electrode while the pH level was measured using a pH meter. The fluoride concentration in the beverages ranged from 0.02±0.00 mg/L to 2.77±0.06 mg/L. Tea was found to have the highest fluoride concentration. The intake of fluoride from consumption of other types of beverages is below the lowest-observed-adverseeffect level (except tea). The pH of the beverages included in the study ranged from 2.20±0.01 to 7.76±0.00. Carbonated beverages (mean pH: 2.98±0.50) were found to be extremely acidic followed by fresh fruit juices (mean pH: 3.38±0.34) and fruit flavoured beverages (mean pH: 3.90±0.92). The correlation between fluoride and pH levels was weak, τ = 0.058 and not statistically significant (p


2021 ◽  
Vol 14 (1) ◽  
pp. 79-84
Author(s):  
A. Mahe ◽  
B. Sabiu ◽  
A.A. Adam ◽  
U.Z. Abdullahi,

Microorganisms are included among the major spoilers of food, they achieve this by using the nutrients present in food material. Susceptibility of microorganisms to the most currently used preservatives has been decreasing. Organic acids have been considered as valuable food preservatives. This study aimed to isolate, identify and determine the effect of citric acid at different pH levels on the survival of E. coli. The E. coli was isolated and a pure culture was obtained after series of sub-ulturing on Eosine Methylene Blue agar. The biochemical tests known as IMViC were performed to confirm the presence of the organism. The organism was also identified using polymerase chain reaction (PCR) in which the DNA was extracted, amplified and viewed by gel electrophoresis. The organism was then inoculated in nutrient broth containing citric acid at pH levels of 3.0, 4.5 and 6.0 in different test tubes. Negative controls were included. Results were analyzed using one way ANOVA to compare the means obtained. Results obtained was positive for indole and methyl red tests but negative for VogesProskauer and citrate tests which confirmed the organism. After 24 hours of inoculation, the results of spectrophotometry showed that at pH level of 3.0, the absorbance was lower than the results obtained at pH level of 4.5 and 6.0. This is an indication of higher reduction in the count of the organism at pH of 3.0. There was significant difference between the control and the test groups (p<0.05) but the difference obtained between the test groups were not significant (p>0.05). Results from this study showed that citric acid could not eliminate the whole organism but was effective in inhibiting the growth of the organism dependent on pH level. This indicates that a pH dependent citric acid can be used as a good preservative.


Author(s):  
P. T. Sharavanan ◽  
V. K. Satya ◽  
M. Rajesh

Root rot of mung bean [Vigna radiata (L.) Wilczek var. radiata] is major disease and claims huge yield loss if they occur in the field. The pathogen is basically soil borne and survivability may vary depends on soil condition. The fungicide chemicals are available to manage the disease; however, the biocontrol agents are nowadays available for the disease management and the microbial activity of the biocontrol agents is influenced by existing soil condition including soil pH. Hence, a study was conducted to find out the halo tolerance capacity of the biocontrol agents against root rot disease in salt affected soils under in vitro, in vivo and field condition. The root rot pathogen Macrophomina phaseolina was isolated from infected root. Efficacy of biocontrol agents against growth of M. phaseolina was assessed in vitro. The results revealed that TNAU strain of Bacillus subtilis reduced the mycelial growth of the M. phaseolina significantly when media supplemented with NaCl at 5% (1.4 cm), 7.5% (1.5 cm), 10% (1.6cm) and 12.5% (1.6 cm) and without NaCl (1.2 cm) and similar trend of reduction also expressed by BCA1 strain of B. subtilis, Pseudomonas fluorescens and Trichoderma viride under in vitro. The performance of the biocontrol agents against the pathogen is slightly reduced when media supplemented with NaCl. The reduction of mycelia weight of M.phaeolina was more in media added with TNAU strain of B.subtilis and the performance of TNAU strain of B.subtilis on reduction of mycelial weight of M.phaseolina is reduced when the broth added with NaCl at 5% (3.15g), 7.5% (3.25g), 10% (3.32g) and 12.5%(3.65g) level and which is followed by P. fluorescens, BCA 1 strain of B. subtilis and Trichoderma viride. Under pot culture conditions, the effect of talc formulated biocontrol agents and challenge inoculation with pathogen was assessed against root rot incidence. It was found that the soil application of TNAU strain of B.subtilis performed better in reducing the root rot incidence at pH of 7.0 (2.37%), 7.5 (4.50%), 8.0 (5.53%) and 8.7 (6.57%) and followed by BCA 1 of B.subtilis in all pH level. Among the biocontrol agents, TNAU strain of B.subtilis applied as seed as well as soil application expressed more population in the rhizosphere in all pH level. The biocontrol agents applied as soil application had more populations of the agents in the soil when compared to seed treatment. The halo tolerance performance of the biocontrol agents was also assessed under field condition in pH of 7.5 and 8.7 during 2019-20 and 2020-21. It was found that the minimum root rot incidence and maximum yield was observed from soil application of TNAU strain of B subtilis at 2.5 kg/ha but the effect is on par with soil application of BCA1 strain of B.subtilis at 2.5 kg/ha.


2021 ◽  
Author(s):  
Amro Othman ◽  
Murtada Saleh Aljawad ◽  
Muhammad Shahzad Kamal ◽  
Mohamed Mahmoud ◽  
Shirish Patil

Abstract Due to the scarcity and high cost of freshwater, especially in the Gulf region, utilization of seawater as a fracturing fluid gained noticeable interest. However, seawater contains high total dissolved solids (TDS) that may damage the formation and degrade the performance of the fracturing fluids. Numerous additives are required to reduce the damaging effect and improve the viscosity resulting in an expensive and non-eco-friendly fracturing fluid system. Chelating agents, which are environmentally benign, are proposed in this study as the replacement of many additives for seawater fracturing fluids. This study focuses on optimizing chelating agents to achieve high viscosity employing the standard industry rheometers. Carboxymethyl Hydroxypropyl Guar Gum (CMHPG) polymer, which is effective in hydraulic fracturing, was used in this research with 0.5 and 1.0 wt% in deionized water (DW) as well as seawater (SW). It was first tested as a standalone additive at different conditions to provide a benchmark then combined with different concentrations, and pH level chelating agents. In this study the hydration test was conducted through different conditions. It was observed that CMHPG, when tested as a standalone additive, provided slightly higher viscosity in SW compared to DW. Also, increasing polymer concentration from 0.5 to 1.0 wt% provided three folds of viscosity. The viscosity did not show time dependence behavior at room temperature for the aforementioned experiments where all hydration tests were run at 511 1/s shear rate. Temperature, however, had a significant impact on both viscosity magnitude and behavior. At 70 °C, the fluid viscosity increased with time where low viscosity was achieved early on but kept increasing with shearing time. Similarly, high pH chelating agents provided time dependant viscosity behavior when mixed with CMHPG. This behavior is important as low viscosity is favorable during pumping but high viscosity when the fluids hit the formation. The study investigates the possibility of utilizing chelating agents with seawater to replace numerous additives. It acts as a crosslinker at early shearing times, where a gradual increase in viscosity was observed and a breaker in the reservoir harsh conditions. It also captures the divalent ions that are common in seawater, which replaces the need for scale inhibitors. The viscosity increase behavior can be controlled by adjusting the pH level, which could be desirable during operations.


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