contamination control
Recently Published Documents


TOTAL DOCUMENTS

707
(FIVE YEARS 153)

H-INDEX

21
(FIVE YEARS 6)

Water ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 133
Author(s):  
Gopal Krishan ◽  
Mavidanam Someshwar Rao ◽  
Rajesh Vashisht ◽  
Anju Chaudhary ◽  
Jaswant Singh ◽  
...  

In recent decades, due to rapid increases in water demand and greater usage of water for irrigation from surface canals, waterlogging problems have been created in the southwest zone of Punjab, coupled with a stagnation in saline zone formation due to salinity ingression. To understand these salinity issues, the present study has been conducted in three districts (Muktsar, Fazilka, and Faridkot) of Punjab to understand the root cause. To this end, groundwater samples were collected from 142 piezometers developed at 40 sites. Electrical conductivity (EC) observations were taken in the field, and collected samples were analyzed for isotopes in the laboratory. Results found that salinity in groundwater arises from the combination of evaporation enrichment and salt dissolution. The dissolved salts may be acquired due to salts from aquifer materials or salts from surface soils dissolving and leaching down with the recharging water. Besides, the zone of interaction is mapped using stable isotopic composition. The study suggests that zone of interaction between aquifers can be effectively used in groundwater augmentation, management, and contamination control at regional and/or global scales to curb water demand in the future.


Yakhak Hoeji ◽  
2021 ◽  
Vol 65 (6) ◽  
pp. 432-440
Author(s):  
Sangjae Lee ◽  
Jaeho Jung ◽  
Minyeong Shin ◽  
Intaek Jang ◽  
Taekyu Kim

Author(s):  
M.M. Ptashnik ◽  
P.S. Zaiats ◽  
S.V. Dudnyk ◽  
F.J. Brukhal ◽  
O.L. Oksimets

As a result of many years of research in a stationary field experiment conducted in the conditions of the northern forest-steppe on Gray forest large-sawn light loamy soil, the regularities of the influence of methods of its main cultivation, doses and terms of herbicide application on the level of contamination of crops with segetal vegetation and the competitiveness of winter wheat in short-term crop rotation were established.It was found that the competitive pressure of weeds on winter wheat both for plowing and flat–cutting loosening to a depth of 20–22 cm was minimal and amounted to 6.9–13.2%, and the crop pressure on weed cenosis was noted in the range of 81.5–84.8%. The use of a herbicide based on D. R. prosulfuron (750 g/kg) increased this indicator to 90%.With flat-cutting loosening, the potential contamination of the upper 0–5-centimeter layer of soil, from which the bulk of weeds germinate, in the crops of the studied crop was 31.3–31.8% higher compared to plowing. Indicators of potential contamination and the rate of germination of weed seeds with this method of basic tillage caused a high level of actual weediness of winter wheat crops in a short-term crop rotation. However, systematic tillage without layer turnover ensured gradual self-cleaning of the lower part of the arable soil layer from weed seeds.The highest yield of winter wheat 6.11 t/ha of grain was obtained during plowing and the autumn period of application of the herbicide based on D. R. prosulfuron (750 g/kg) at a rate of 20 g/ha in the development phase of the BBCH 11–13. The use of the herbicide in autumn compared to spring periods provided an increase in the grain yield by 0.24–0.54 t/ha for plowing and by 0.48–0.64 t/ha for non – polar cultivation.Economically, the most appropriate technology for controlling segetal vegetation in winter wheat crops is recognized, which provides for plowing to a depth of 20–22 cm as the main tillage with the introduction of N80P60K80 and earning by-products of its predecessors into the soil. To increase the effectiveness of crop contamination control in the integrated plant protection system, it is also proposed to use autumn application of a herbicide based on D. R. prosulfuron (750 g/kg) at a dose of 20 g/ha in the phase of 2–3 leaves in the culture.


Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1639
Author(s):  
Fujen Wang ◽  
Indra Permana ◽  
Dibakar Rakshit ◽  
Bowo Yuli Prasetyo

Controlling contamination via proper airflow distribution in an operating room becomes vital to ensure the reliable surgery process. The heating, ventilation, and air conditioning (HVAC) systems significantly influence the operating room environment, including temperature, relative humidity, pressurization, particle counts, filtration, and ventilation rate. A full-scale operating room has been investigated extensively through field measurements and numerical analyses. Computational fluid dynamics (CFD) simulation was conducted and verified with the field measurement data. The simulation was analyzed with three different operating room schemes, including at-rest conditions (case 1), normal operational conditions with personnel (case 2), and actual conditions with personnel inside and some medical equipment blocking the return air (case 3). The concentration decay method was used to evaluate this study. The results revealed that the contamination concentration in case 1 could be diluted quickly with the average value of 404 ppm, whereas the concentration in case 2 slightly increased while performing a surgery with the average value of 420 ppm. The return air grilles in case 3, blocked by obstacles from some medical equipment, resulted in the average concentration value of 474 ppm. Other than that, the contaminant dilution could be obstructed dramatically, which revealed that proper and smooth airflow distribution is essential for contamination control. The ventilation efficiency of case 2 and case 3 dropped around 6% and 17.91% compared to case 1 in the unoccupied and ideal condition. Ventilation efficiency also decreased along with decreasing the air change rate per hour (ACH), while with increasing ACH, the ventilation efficiency in case 3 actually increased, approaching case 2 in the ideal condition.


2021 ◽  
Author(s):  
Krishnaraj Ramaswamy ◽  
Leta Tesfaye Jule ◽  
Nagaprasad Nagaraj ◽  
Kumaran subramanian ◽  
Shanmugam Ramaswamy ◽  
...  

Abstract Right from the olden days, many products have been made according to foundry practices in order to generate prosperity in the societies in which they operate, while reaping these types of benefits through the operation of foundries. It is alarming that the emissions released by foundries affect human health. Therefore, foundries installed Pollution Control devices (PCDs), in accordance with this development; researchers examined the effectiveness of these PCDs in controlling emissions from foundries in different parts of the world. The emission control obtained by installing these PCDs is explained in this article based on the data gathered from the survey. The result of the study indicated that the cartridge filter built into the induction furnace achieves the best efficiency in controlling contamination from foundries. Interestingly, the operation of the cartridge filter has yet to be documented. Therefore, the construction, operation, the performance of the cartridge filter, and its efficiency in achieving contamination control in foundries are described. The article ends by emphasizing the need to conduct surveys in foundries in which a cartridge filter is installed. The results of this study will provide useful information on the use of cartridge filters in induction furnaces to reduce foundry emissions.


2021 ◽  
Vol 64 (1) ◽  
pp. 1-17
Author(s):  
Dilip Ashtekar

Abstract Currently, limited guidance is available for the contamination control of visible particles for the manufacture of sterile devices; thus, a comprehensive guidance is warranted. Sterile devices require stringent control of visible particulates to ensure proper functionality, performance assurance of sterility, reliability, patient safety, efficacy, and product quality. This paper outlines practical and science-based strategies to prevent/minimize visible particle contamination from non-process related extrinsic and process related intrinsic sources. Witness plates are proposed as a comprehensive strategy for the real time detection of visible particles, sources of extrinsic and intrinsic visible particles, and methods to identify particle types. Implementing the control measures described herein, which include air ionization units for the control and neutralization of static charges, would maximize device yield and quality, thus reducing rework and leading to increased profitability. Installing validated air ionization systems at appropriate manufacturing and processing locations, storage, product transfer areas, and gown-up rooms can significantly reduce visible particle contamination accumulation, dispersion, and yield losses. Implementing effective material transfer practices can further minimize the risk of introduction of unwanted particles and particle dispersion within classified areas. Also described are additional control measures, such as material systems and supply chain controls, good facility design, gowning practices, manufacturing equipment and tool controls, and manual visual inspections which would further contribute to the overall reduction of particle burden. Crucial elements of an effective particle removal process are the dry and wet cleaning processes and the facility surveillance program. Process-product-particle traceability matrices can serve as effective tools to promptly identify trends and reduce device conformity defects. For this paper, the meaning of the term particle only includes particulates and particulate matter. Microbial contamination control approaches, including facility decontamination, are outside the scope of this paper.


2021 ◽  
Vol 13 (21) ◽  
pp. 12123
Author(s):  
Aleksandra Bogdanowicz ◽  
Monika Zubrowska-Sudol ◽  
Andrzej Krasinski ◽  
Miroslaw Sudol

Research conducted so far on the presence of microplastics in the environment shows that these items are ubiquitous pollutants and therefore constitute an inherent part of our lives. This constitutes a significant problem in many aspects, and one of them is the correct identification of microplastics in environmental samples. Environmental samples can be easily contaminated by plastic microparticles from other sources if proper precautions are not taken during sampling and analysis. The consequence of not taking this cross-contamination into account when analysing the results may be their significant overestimation. This review aims to draw attention to the problem of cross-contamination that accompanies the collection and analysis of samples for the presence of microplastics, and to discuss this issue in a comprehensive manner. The article indicates potential sources of cross-contamination, lists the mitigation methods, and describes the possibilities of assessing this type of contamination. Moreover, the review examines how cross-contamination control appears in practice, based on the available literature data.


2021 ◽  
Author(s):  
Xinyi Guan ◽  
H Jochen Schenk ◽  
Mary R. Roth ◽  
Ruth Welti ◽  
Julia Werner ◽  
...  

Xylem sap of angiosperm species has been found to include low concentrations of polar lipids and nanoparticles, including surfactant-coated nanobubbles. Although the nanoparticles have been suggested to consist of polar lipids, no attempt has been made to determine if nanoparticle and lipid concentrations are related. Here, we examined concentrations of nanoparticles and lipids in xylem sap and contamination control samples of six temperate angiosperm species with a NanoSight device and based on mass spectrometry. We found (1) that the concentration of nanoparticles and lipids were both diluted when an increasing amount of sap was extracted, (2) that their concentrations were significantly correlated in three species, (3) that their concentrations were affected by vessel anatomy, and (4) that concentrations of nanoparticles and lipids were very low in contamination-control samples. Moreover, there was little seasonal difference, no freezing-thawing effect on nanoparticles, and little seasonal variation in lipid composition. These findings indicate that lipids and nanoparticles are related to each other, and largely do not pass interconduit pit membranes. Further research is needed to examine the formation and stability of nanoparticles in xylem sap in relation to lipid composition, and the complicated interactions among the gas, liquid, and solid phases in xylem conduits.


Sign in / Sign up

Export Citation Format

Share Document