scholarly journals Does Activated Silver Reduce Recontamination Risks in the Reservoirs of Ceramic Water Filters?

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 1108
Author(s):  
Regula Meierhofer ◽  
Pascal Rubli ◽  
Jared Oremo ◽  
Alloyce Odhiambo
Keyword(s):  
Water Storage ◽  
Water Reservoir ◽  
Silver Ions ◽  
Field Trials ◽  
Metallic Silver ◽  
Silver Coating ◽  
Filter Performance ◽  
Ceramic Water Filters ◽  
Significant Difference ◽  
Water Filters

Efforts to provide safe water are challenged by recontamination and regrowth of pathogens in treated water during storage. This study evaluated the potential of metallic silver with a chemically etched surface to reduce recontamination risks during water storage in ceramic water filters. Batch experiments were conducted in the laboratory with water storage buckets containing three configurations of varying amounts of silver. Field trials in a rural area in Kenya assessed the effect of the same configurations in the storage buckets of locally produced ceramic pot filters without colloidal silver coating. The tests revealed that the etched silver slightly reduced microbiological recontamination risks during water storage despite the low diffusion of silver ions (<5 µg Ag/L). The effect was strongly influenced by water chemistry parameters. A statistically significant difference in the removal of E. coli (Δ Log Removal Value (LRV) = 0.6) and total coliforms (Δ LRV = 1.7) was found between households using a filter with silver in the water reservoir and those using a filter without silver. Multivariate regression of water handling factors and hygiene practices on filter performance revealed that the presence of silver in the reservoir and cleaning the filter element with a brush were associated with a better filter performance.

Ceramic Water Filters as a Response Technology to Geo-Hazards

2018 ◽  
Vol 5 (1) ◽  
pp. 1-8
Author(s):  
E. McBean ◽  
◽  
G. Huang ◽  
Yongping Li ◽  
Yanfeng Li ◽  
...  
Keyword(s):  
Ceramic Water Filters ◽  
Water Filters

Virus removal efficiency of ceramic water filters: effects of bentonite turbidity

2013 ◽  
Vol 14 (2) ◽  
pp. 304-311 ◽  
Author(s):  
Cameron Farrow ◽  
Edward McBean ◽  
Hamidreza Salsali
Keyword(s):  
Removal Efficiency ◽  
Potable Water ◽  
Source Water ◽  
Virus Removal ◽  
Ceramic Water Filters ◽  
Point Of Use ◽  
Cake Layer ◽  
Human Enteric Viruses ◽  
Removal Efficiencies ◽  
Water Filters

Ceramic water filters (CWFs) are utilized in many developing countries as point-of-use (POU) water treatment devices, to reduce waterborne pathogens in potable water. Virus removal efficiencies of several CWFs are investigated under various influent conditions using MS2 (ATCC: 15597-B1) as a surrogate phage for human enteric viruses. The addition of bentonite turbidity (6–8 NTU) in the influent source water showed increased viral removal efficiency of CWFs by 0.1–0.2 log compared to tests involving clear (&lt;1 NTU) influents. Trials employing an applied clay cake layer, formed using highly turbid influent source water (100 NTU) and no cleaning regime between trials, resulted in viral removal efficiency values of 1.5–2.5 log, compared to 0.2–0.5 log during non-obstructed trials.

Crop nutritional management affects soil structure and soil functions at different scales.

2021 ◽  
Author(s):  
William Rickard ◽  
Marcos Paradelo Perez ◽  
Aurelie Bacq-Labreuil ◽  
Andy Neal ◽  
Xiaoxian Zhang ◽  
...  
Keyword(s):  
Soil Structure ◽  
Nutrient Management ◽  
Water Storage ◽  
Nutrient Addition ◽  
Inorganic Nutrient ◽  
Nutritional Management ◽  
Manure Treatment ◽  
Significant Difference ◽  
Lower Porosity

&lt;p&gt;Soil organic matter is associated with important biological and physical functions. There are many theories to interpret this association, as yet there is not a fully developed understanding linking soil properties to nutritional management in arable systems.&lt;/p&gt;&lt;p&gt;We used X-ray computed tomography to analyse soil structure at the core and aggregate scale on the Broadbalk long term experiment (Hertfordshire, England). Here we present results of the treatments that have been under continuous wheat for 175 years. Corresponding to treatments that the only difference between the treatments is the nutrient management regime, with the exception of the baseline, or &amp;#8216;wilderness&amp;#8217; treatment in which the plot was left unmanaged and has returned to mature woodland since 1882. The other nutrient treatments correspond to inorganic fertiliser addition with and without phosphorus, farmyard manure, and no added nutrient.&lt;/p&gt;&lt;p&gt;At core scale (40 &amp;#181;m resolution) we capture macro pore structures that are responsible for convective flow, while the aggregate scale images (1.5 &amp;#181;m resolution) include structures responsible for retention of water by capillary forces.&amp;#160; Therefore, a comparison of images taken at the two resolutions 1.5 &amp;#181;m and 40 &amp;#181;m provides information on how soil partitions between drainage and storage of water, and therefore on the air water balance under different environmental contexts.&lt;/p&gt;&lt;p&gt;The results are presented as a state-space plot of simulated permeability vs. porosity for each treatment. We find that nutrient management resulted in two distinct states at aggregate scale corresponding to water storage potential. Inorganic nutrient management resulted in structures of lower porosity and lower simulated permeability. There was no significant difference between each treatment, or between these treatments and the treatment with no nutrient addition. By comparison, the wilderness and manure treatments had higher porosity and higher permeability, with no significant difference between them.&lt;/p&gt;&lt;p&gt;At core scale, the results are slightly different. Again, the inorganic nutrient management treatments had lower porosity and simulated permeability, with no significant difference between them, and between them and the treatment with no nutrient addition. However, the manure treatment had a significantly lower porosity and permeability than the wilderness treatment. We conclude that long-term cultivation with organic nutrient management results in a similar capacity for water storage and transport to roots than a wilderness control, but that long-term management using a purely inorganic nutrient regime results in a smaller capacity for water storage and a lower transport rate to roots. Organic inputs, roots and plant detritus ploughed into the soil after harvest had no significant impact. Infiltration potential is highest in the wilderness control, lower for the manure treatment, and lowest for the inorganic nutrient management treatment. Again, inputs of organic nutrients from plants had no significant impact. We interpret these findings in terms of a previously hypothesised self-organising feedback loop between microbial activity and soil structure.&lt;/p&gt;

scholarly journals Studi Kepadatan Jentik Nyamuk di Kelurahan Tebing Tinggi Kecamatan Tebing Tinggi Kabupaten Tanjung Jabung Barat Jambi Tahun 2019

2020 ◽  
Vol 20 (1) ◽  
pp. 302
Author(s):  
Sondang Siahaan ◽  
Rina Fauziah
Keyword(s):  
Water Storage ◽  
Health Sector ◽  
Water Reservoir ◽  
Mosquito Larvae ◽  
Water Reservoirs ◽  
Populated Area ◽  
Cross Sectional ◽  
Breeding Grounds ◽  
Daily Water ◽  
External Water

Mosquitoes have a very important meaning in the health sector because of their role as vectors of various diseases. Diseases transmitted by mosquitoes include dengue fever, malaria and filariasis. These three diseases are transmitted from one person to another through vector intermediaries. Vector is a creature that acts as an intermediary for transmitting   diseases. Tebing Tinggi Village is a densely populated area. The density of the population as well as the constraints of clean water make a lot of water reservoirs to store daily water needs. This can potentially be a breeding ground for mosquito larvae. This study was conducted to determine the density of mosquito larvae, to find out the percentage of house index and container index. This study used a visual method, with a cross sectional approach. Based on the results of research from 18 houses (19.78%) that were larvae positive from 91 houses examined and found 22 containers (5.78%) positive larvae from 380 containers examined. 331 containers of larvae were found in the reservoir of deep water as much as 18 containers (5.43%) and as many as 49 containers of  larvae were found in the external water reservoir (12.24%). The density of mosquito larvae in Tebing Tinggi area is categorized as being with density figures 3 and 4. The amount on the surface of the presence of mosquito larvae in water reservoirs in the house should  the community pay more attention to the cleanliness of water reservoirs and to close water storage so that they are not breeding grounds.

scholarly journals Influence of Water Aging on Microtensile Bond Strength of a Flowable and a Packable Bulk-fill Resin Composites to Dentin

2020 ◽  
Vol 8 (D) ◽  
pp. 112-117
Author(s):  
Ayah Atif Selim ◽  
Ahmed Fawzy Abo Elezz ◽  
Rehab Khalil Safy
Keyword(s):  
Bond Strength ◽  
Storage Time ◽  
Resin Composite ◽  
Water Storage ◽  
Aging Effect ◽  
Mean Value ◽  
Control Group ◽  
Microtensile Bond Strength ◽  
Significant Difference ◽  
Influence Of Water

AIM: Investigation of the aging effect on the microtensile bond strength (μTBS) of bulk-fill resin composite (RC) versus a conventionally incrementally applied one. MATERIALS AND METHODS: A total number of 45 sound human impacted third molars extracted molars have been selected to prepare specimens for the μTBS test. Teeth were randomly divided into three groups (C) according to type of RC material which used for restoring the teeth. Where nanohybrid RC (Grandio®SO) was used as the control Group (C1), packable bulk-fill RC (X-tra fil®) was used for restoring teeth in C2 group and flowable bulk-fill RC (X-tra base®) was used for restoring teeth in C3 group. Each group was further subdivided into 3 subgroups (n = 5) according to the water storage time, where in subgroup 1; teeth were stored for 24 h, subgroup 2; teeth were stored for 3 months while for subgroup 3; and teeth were stored for 6 months. After water storage, teeth were sectioned for preparation of μTBS testing beams. Maximum tensile stresses were recorded in megapascal (MPa). RESULTS: After 24 h of water storage, the X-tra base® showed a higher statistically significant μTBS to dentin (33.82 ± 9.84 MPa) than did the other two types of RCs. After 3 months, the X-tra fil® showed the lowest mean value of μTBS (10.90 ± 5.66 MPa), meanwhile, after 6 months of water storage Grandio®SO showed the highest mean value of μTBS (15.85 ± 6.76 MPa). Regardless of the time the X-tra fil® showed the lowest mean of μTBS (15.07 ± 11.73 MPa), while there is no significant difference between the X-tra base® and Grandio®SO. Furthermore, the water aging adversely affects μTBS values which deceased gradually by time. CONCLUSION: The packable bulk-fill RC characterized by lower μTBS to dentin in comparison to the flowable bulk fill and the incrementally applied nanohybrid RCs. Furthermore, the μTBS of the three tested materials decreased gradually by aging.

scholarly journals Calcium nitrate and ammonium nitrate limestone as sources of nitrogen for oats and barley

1961 ◽  
Vol 33 (1) ◽  
pp. 159-168
Author(s):  
Pentti Hänninen ◽  
Armi Kaila
Keyword(s):  
Ammonium Nitrate ◽  
Nitrogen Content ◽  
Calcium Nitrate ◽  
Field Trials ◽  
The Other ◽  
Nitrogen Fertilizers ◽  
Malting Barley ◽  
Growing Period ◽  
Significant Difference ◽  
Cent Level

Calcium nitrate and ammonium nitrate limestone (»Oulunsalpietari») were compared as the nitrogen fertilizer for oats in 15 field trials and for barley in one trial. The trials were carried out in summers 1959 and 1960 in various places in Finland. The split plot technique was employed in order to reduce the variation as much as possible. In 1959 the amounts of nitrogen applied as these two fertilizers to the corresponding halves of the plots were 25 and 50 kg/ha. In 1960 also higher applications were used: 75 and 100 kg/ha of N. In three trials these fertilizers were compared both as a surface dressing and worked in. Visual observations suggested about 5—6 weeks after sowing a darker green colour in the stands treated with calcium nitrate as compared with the other half treated with ammonium nitrate limestone. These differences later disappeared. In some trials a higher nitrogen content of the plants from the calcium nitrate stands could be demonstrated during this period. The uptake of nitrogen by plants was regularly followed throughout the growing period. Owing to the large variation, usually, no statistically significant difference between the effect of the fertilizers could be detected. In a few cases the superiority of calcium nitrate could be demonstrated. No differences in the ripening could be found. In most trials there was a fairly regular tendency to higher yields and higher nitrogen content in the grain and straw produced by calcium nitrate. Yet, only in a few cases were the differences statistically significant at the five per cent level. Thus, it was concluded that on the basis of the results of these trials ammonium nitrate limestone and calcium nitrate may be considered practically equal as nitrogen fertilizers for oats. There was no difference in the yields of barley produced by these two fertilizers, but the nitrogen content of grains was significantly lower with ammonium nitrate limestone than with calcium nitrate. This may be worth further study in connection with the production of malting barley.

Mycotoxins in organically versus conventionally produced cereal grains and some other crops in temperate regions

2016 ◽  
Vol 9 (5) ◽  
pp. 755-770 ◽  
Author(s):  
G. Brodal ◽  
I.S. Hofgaard ◽  
G.S. Eriksen ◽  
A. Bernhoft ◽  
L. Sundheim
Keyword(s):  
Farming Systems ◽  
Weather Conditions ◽  
Field Trials ◽  
Cereal Grains ◽  
Organic System ◽  
Mycotoxin Contamination ◽  
Significant Difference ◽  
Apple Products ◽  
Low Levels ◽  
The Difference

This paper presents peer-reviewed studies comparing the content of deoxynivalenol (DON), HT-2+T-2 toxins, zearalenone (ZEA), nivalenol (NIV), ochratoxin A (OTA) and fumonisins in cereal grains, and patulin (PAT) in apple and apple-based products, produced in organically and conventionally grown crops in temperate regions. Some of the studies are based on data from controlled field trials, however, most are farm surveys and some are food basket surveys. Almost half of the studies focused on DON in cereals. The majority of these studies found no significant difference in DON content in grain from the two farming systems, but several studies showed lower DON content in organically than in conventionally produced cereals. A number of the investigations reported low DON levels in grain, far below the EU limits for food. Many authors suggested that weather conditions, years, locations, tillage practice and crop rotation are more important for the development of DON than the type of farming. Organically produced oats contained mainly lower levels of HT-2+T-2 toxins than conventionally produced oats. Most studies on ZEA reported no differences between farming systems, or lower concentrations in organically produced grain. For the other mycotoxins in cereals, mainly low levels and no differences between the two farming systems were reported. Some studies showed higher PAT contamination in organically than in conventionally produced apple and apple products. The difference may be due to more efficient disease control in conventional orchards. It cannot be concluded that any of the two farming systems increases the risk of mycotoxin contamination. Despite no use of fungicides, an organic system appears generally able to maintain mycotoxin contamination at low levels. More systematic comparisons from scientifically controlled field trials and surveys are needed to clarify if there are differences in the risk of mycotoxin contamination between organically and conventionally produced crops.

Histopathological Changes of Organs (Lungs, Liver, Kidney, and Brain) After Using Two Types of AgiCoat and Acticoat Nanosilver Dressings on Deep Second-Degree Burn in Rat

2019 ◽  
Vol 41 (1) ◽  
pp. 141-150 ◽  
Author(s):  
Hamid Karimi ◽  
Noor-Ahmad Latifi ◽  
Ali Zare Mehrjerdi ◽  
Babak Jafarnejad ◽  
Ali-Mohammad Karimi
Keyword(s):  
Wound Healing ◽  
Silver Ions ◽  
The Body ◽  
Male Rats ◽  
Histopathological Changes ◽  
Sprague Dawley ◽  
Tissue Samples ◽  
Degree Burn ◽  
Significant Difference ◽  
Second Degree

Abstract Prevention of infections is a very important issue in treating the burn wounds. The nanosilver dressings have many promising advantages, but absorption of silver ions and its adverse effects to the body were always a question. The aim of this study was to compare Silver serum levels and acute toxic effects of nanosilver on histopathology of organs (lungs, liver, kidney, spleen, and brain) in two types of AgiCoat and Acticoat (nanosilver) dressings on second-degree deep burn in rat. This is an experimental study conducted in our animal laboratory. We divided 24 Sprague–Dawley male rats weighing 300 to 350 randomly into two groups. After anesthesia, a second deep-degree burn was made over dorsal skins of rats by standard method. For group A, Agicoat and, for group B, Acticoat dressings were used. The dressings were changed every 3 days with AgiCoat and Acticoat, respectively. After 14 days, we got blood samples and tissue samples taken from heart, liver, kidneys, spleen, lungs, and brain and a sample from dorsal skin of the rat for histopathological examinations. The results showed that the levels of serum silver in both groups were significantly higher than the standard level (1.22 part per million (PM); AgiCoat, P = .017; Acticoat, P = .000), but there was no significant difference between the groups (P = .551). Examination of the relationship between the level of serum silver and histopathological changes in liver showed that hepatotoxicity of AgiCoat was higher compared with Acticoat and the difference was significant (P = .002). There were no pathological changes in brain, kidneys, spleen, heart, and lungs. Wound healing was faster in Acticoat group. The nanosilver dressings can cause toxicity in liver but not in kidney, brain, spleen, heart, and lungs. Liver pathology and hepatotoxicity were more prominent in AgiCoat group. Wound healing was faster in Acticoat group.

scholarly journals Field Research on Mixing Aeration in a Drinking Water Reservoir: Performance and Microbial Community Structure

2019 ◽  
Vol 16 (21) ◽  
pp. 4221 ◽  
Author(s):  
Zizhen Zhou ◽  
Tinlin Huang ◽  
Weijin Gong ◽  
Yang Li ◽  
Yue Liu ◽  
...  
Keyword(s):  
Drinking Water ◽  
Microbial Community ◽  
Water Temperature ◽  
Water Reservoir ◽  
Field Research ◽  
Pollutant Removal ◽  
Chl A ◽  
Drinking Water Reservoir ◽  
Aeration System ◽  
Significant Difference

Field research on the performance of pollutant removal and the structure of the microbial community was carried out on a drinking water reservoir. After one month of operation of a water-lifting aeration system, the water temperature difference between the bottom and the surface decreased from 9.9 to 3.1 °C, and the concentration of the dissolved oxygen (DO) in the bottom layer increased from 0 to 4.2 mg/L. The existing stratification in the reservoir was successfully eliminated. Total nitrogen (TN), total phosphorus (TP), and total organic carbon (TOC) concentrations were reduced by 47.8%, 66.7%, and 22.9%, respectively. High-throughput sequencing showed that Proteobacteria, Bacteroides, and Actinomycetes accounted for 67.52% to 78.74% of the total bacterial population. Differences in the bacterial changes were observed between the enhanced area and the control area. With the operation of the water-lifting aeration system, the populations of bacteria of the main genera varied temporally and spatially. Principal component analysis pointed out a clear evolution in the vertical distribution of the microbial structure controlled by the operation of the aeration system. Permutational analysis of variance showed a significant difference in the microbial community (p < 0.01). Redundancy analysis showed that physical (water temperature, DO) and chemical environmental factors (Chl-a, TOC, TN) were the key factors affecting the changes in the microbial communities in the reservoir water. In addition, a hierarchical partitioning analysis indicated that T, Chl-a, ORP, TOC, pH, and DO accounted for 24.1%, 8.7%, 6.7%, 6.2%, 5.8%, and 5.1% of such changes, respectively. These results are consistent with the ABT (aggregated boosted tree) analysis for the variations in the functional bacterial community, and provide a theoretical basis for the development and application of biotechnology.

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