This focus article has been prepared by Cat Man, veterinary lead of the APHA Wildlife Expert Group, and Susanna Williamson, veterinary lead of the APHA Pig Expert Group.
•Seawater-in-Marpol oil emulsion is challenging for waste treatment.•Selected Anionic Demulsifies under 70°C are effective tools for water removal in Marpol oil.•Recovered Marpol oil was recommended ...for waste-to-fuel as its property of high energy value and low sulphur and PCBs content.
Marpol oil waste composed of wasted oil with seawater which is challenging for waste treatment. Therefore, emulsified seawater has to be broken down for recovering the oil content involving chemical destabilizer to disperse water droplets or destroy emulsifiers.
This study aims to evaluate 37 products of demulsifiers (cationic, non-ionic and anionic) based on ability of water removal from Marpol oil waste. The results show that anionic and nonionic surfactants were found to be effective demulsifiers exhibiting good property for oil and water separation. The efficiency of the nonionic demulsifiers increases with the dosage up to a certain extent after which the efficiency falls. However, anionic demulsifiers do not show any decrease in efficiency at higher doses. Among all the tested anionic demulsifiers, sodium dioctyl sulfosuccinate (ALCOPOL O70PG), sodium dioctyl sulfosuccinate (ALCOPOL O CONC 60%) and Oligoguluronate (DP9-6661) were with most outstanding performance. Additionally there is a general improvement in the performance of screened demulsifiers with increased temperature (70°C). Sodium dioctyl sulfosuccinate (ALCOPOL O70PG), sodium dioctyl sulfosuccinate (ALCOPOL O CONC 60%) and sodium dodecyl benzene sulphonate (DP9-6661) reached water removal performance percentage as 75%, 66.3% and 56.7% respectively after 30h. When the water content of recovered oil was reduced to a certain level (below 10%), the heat valve was about 40MJ/kg. The recovered Marpol oil waste was suggested to apply for low-quality fuel usage such as cement kilns and waste incinerators with its property of high energy value, low sulphur content and Polychlorinated Biphenyls (PCBs).
Restaurant oil and grease management in Hong Kong Yau, Yiu-Hung; Rudolph, Victor; Lo, Cat Chui-man ...
Environmental science and pollution research international,
08/2021, Letnik:
28, Številka:
30
Journal Article
Recenzirano
Oil and grease (O&G) in wastewater can be considered as two parts or proportion contained in emulsion which exceeded O&G standard. Most of oil becomes emulsified with water when they pass through ...grease trap and discharged in the effluents. Thus, it may indicate that either treatment of grease traps or standards for O&G content stipulated in technical memorandum of Water Pollution Control Ordinance (WPCO) do not reflect the actual situation. Existing grease traps should be upgraded to meet the requirements of WPCO. Alternative technologies need to be developed to tackle this unsolved problem. Good management and practices are also important to ensure proper collection and waste recycling rather than just disposing effluent into drains. Collected O&G content can be recycled as valuable products such as biofuel, flotation agent, or other derivatives. This approach not only protects the environment by improving water quality, it also encourages large flow restaurant operators to recycle oil and grease content towards cleaner production.
This focus article has been prepared by Paul Duff, Paul Holmes, James Aegerter, Cat Man, Ed Fullick, Scott Reid, Fabian Lean, Alex Núñez, Rowena Hansen, Joanna Tye, Lévon Stephan and Ian Brown of the ...APHA and Caroline Robinson of SRUC.
The need for wildlife surveillance is as great now as it ever has been. Here, members of the APHA’s Diseases of Wildlife Scheme explain why their work is important.
Summary We evaluated the predictive value of the COPD assessment test (CAT™) for exacerbation in the following six months or time to first exacerbation among COPD patients with previous ...exacerbations. COPD outpatients with a history of exacerbation from 19 hospitals completed the CAT questionnaire and spirometry over six months. Exacerbation events were prospectively collected using a structured questionnaire. The baseline CAT score categorised into four groups (0–9, 10–19, 20–29, and 30–40) showed strong prediction for time to first exacerbation and modest prediction for any exacerbation or moderate-severe exacerbation (AUC 0.83, 0.64, and 0.63 respectively). In multivariate analyses, the categorised CAT score independently predicted all three outcomes ( p = 0.001 or p < 0.001). Compared with the lowest CAT score category, the higher categories were associated with significantly shorter time to first exacerbation and higher exacerbation risks. The corresponding adjusted median time was >24, 14, 9, and 5 weeks and the adjusted RR was 1.00, 1.30, 1.37, and 1.50 in the category of 0–9, 10–19, 20–29, and 30–40 respectively. Exacerbation history (≥2 vs. 1 event in the past year) was related to time to first exacerbation (adjusted HR 1.35; p = 0.023) and any exacerbation during the study period (adjusted RR 1.15; p = 0.016). The results of this study support the use of the CAT as a simple tool to assist in the identification of patients at increased risk of exacerbations. This could facilitate timely and cost-effective implementation of preventive interventions, and improve health resource allocation. Trial registration Clinicaltrials.gov: NCT01254032.
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•The active sites on the MWNTs’ sidewall were increased by a two-step purification process.•The interaction of the adsorbate molecules mainly occurred at the defect sites of MWNTs’ ...sidewall.•Highly sensitive mass-type SO2 gas sensor was fabricated by using QCM coated with the functional MWNTs.•The increase in the active sites increases the adsorption of the SO2 molecules on surface of the MWNTs.
In this work, a room temperature gas sensor based on functional multi-wall carbon nanotubes (MWNTs) coated quartz crystal microbalance (QCM) was developed. The two-step purification process was used to remove amorphous carbon and inactivated catalyst particles, and added functional groups on the sidewall of tubes. The functional MWNTs were then dispersed in deionized water to deposit on the gold electrode of the QCM. The operative MWNTs-coated QCM sensor was tested with toxic hazardous gases such as hydrogen sulfide, hydrogen, nitrogen dioxide, carbon monoxide, and sulfur dioxide. The sensing results expose that the fabricated sensor exhibits good sensitivity with sulfur dioxide gas at room temperature. The sensitivity of the functional MWNTs based sensor presented to be superior to that of the as-grown MWNTs based sensor.
Abstract
We present the first results from the Transiting Exoplanet Survey Satellite (TESS) on the rotational and pulsational variability of magnetic chemically peculiar A-type stars. We analyse TESS ...2-min cadence data from sectors 1 and 2 on a sample of 83 stars. Five new rapidly oscillating Ap (roAp) stars are announced. One of these pulsates with periods around 4.7 min, making it the shortest period roAp star known to date. Four out of the five new roAp stars are multiperiodic. Three of these and the singly periodic one show the presence of rotational mode splitting. Individual frequencies are provided in all cases. In addition, seven previously known roAp stars are analysed. Additional modes of oscillation are found in some stars, while in others we are able to distinguish the true pulsations from possible aliases present in the ground-based data. We find that the pulsation amplitude in the TESS filter is typically a factor of 6 smaller than that in the B filter, which is usually used for ground-based observations. For four roAp stars we set constraints on the inclination angle and magnetic obliquity, through the application of the oblique pulsator model. We also confirm the absence of roAp-type pulsations down to amplitude limits of 6 and 13 $\mu$mag, respectively, in two of the best characterized non-oscillating Ap (noAp) stars. We announce 27 new rotational variables along with their rotation periods, and provide different rotation periods for seven other stars. Finally, we discuss how these results challenge state-of-the-art pulsation models for roAp stars.
•GO was an excellent candidate for the sensing layer.•NO2, SO2, CO, NH3 adsorption possibility of GO as a potential mass-type gas sensor.•GO-NSs coated QCM sensor exposed good reproducibility and ...long-term stability.•A new trend in developing of the gas sensor base on the GO-NSs coated QCM sensor.
Graphene oxide (GO) is an excellent suitable material as a gas-sensing layer due to its adsorption ability towards toxic gas molecules. In this work, GO nanosheets (GO-NSs) were employed in a mass-type toxic gas sensor using a quartz crystal microbalance (QCM) transducer. The sensor was prepared by spraying the GO-NS suspension on the working electrode surface of the QCM. The gas-sensing properties of the sensor were examined with various concentrations of toxic gases, including NO2, SO2, CO, and NH3. The results demonstrated that the adsorption potential of the prepared GO-NSs makes them a promising candidate for the sensing layer of mass-type gas sensors to detect toxic gases.
This article describes the impact of factors affecting the implementation of Green Tourism as a sustainable tourism type in Da Nang City after the Covid-19 pandemic and in the near future. Today, air ...pollution and the Covid-19 pandemic are urgent problems that people are facing to overcome and stabilize social life as well as the economy. With the title of Vietnam's National Green City (Danang city's e-portal, 2018), Da Nang - one of the most famous tourist cities in Vietnam, has many favorable conditions for the development of the “green tourism” model, contributing to the development of a sustainable green economy. We use qualitative research to establish the hypotheses in this research. In the quantitative research, data were collected from business owners dealing in accommodation and travel services in the tourism industry in Da Nang city through questionnaires. The data analysis methods used in this study are Cronbach and EFA methods, correlation, and regression. The results show that there are 4 factors: Cost, Green Awareness, Competitive Advantages, and Policy of Government affecting the implementation of the green tourism model in Da Nang. Most of the business owners providing accommodation and travel services in the tourism industry in Da Nang city are aware of the importance and potential of developing "green tourism" in Da Nang in the future.
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