Urban snow dump quality and pollutant reduction in snowmelt by sedimentation

1993 ◽  
Vol 20 (1) ◽  
pp. 9-21 ◽  
Author(s):  
R. L. Droste ◽  
J. C. Johnston
Keyword(s):  
Suspended Solids ◽  
Specific Conductance ◽  
Fecal Coliforms ◽  
Snowmelt Runoff ◽  
Dump Site ◽  
Time Period ◽  
Low Concentrations ◽  
Pollutant Reduction ◽  
Very High ◽  
Better Than

Four snow dump sites in the Ottawa-Carleton region were analyzed for BOD, total and fecal coliforms, chlorides, sulfates, specific conductance, suspended solids, metals, and other parameters. Sites were sampled at various depths during the months of February through May. There was no trend in variation of quality in the dump piles with time. The black crust that formed on the top of the pile was heavily laden with solids and metals.Snowmelt samples were also taken over the same time period and analyzed for the above parameters. The process of snowmelt reduced the concentrations of most metals and suspended solids from the dump by 50–70%. Dissolved constituents in snowmelt are discharged at very high levels during the initial stages of snowmelt and rapidly decrease to low concentrations. Suspended solids and associated metals in snowmelt exhibited variability with snowmelt conditions and the state of the dump pile. The concentrations of a number of metals in settled snowmelt exceeded provincial objectives for surface waters.An analysis of settled snow dump and snowmelt samples for suspended solids and metals was conducted for settling periods of 1, 6, 12, and 24 h. A settling time from 2 to 6 h would achieve most of the removal that could be expected from sedimentation. The overall removal of suspended solids and the metals in settled snowmelt would generally be better than 90%. There were no significant trends in removal behavior as the snowmelt season progressed. The removal of metals lagged slightly behind the removal of suspended solids after settling because of the stronger association of metals with smaller sediment particles. The residue at the dump site is highly contaminated. Key words: snowmelt, runoff, stormwater, sedimentation, road deicing, snow dump, pollution.

PHYSICO-CHEMICAL ASPECTS OF YAMUNA RIVER AT GOKUL BARRAGE, MATHURA (UP) INDIA

2017 ◽  
Vol 23 (2) ◽  
Author(s):  
AJAY KUMAR RAJAWAT ◽  
PRAVEEN KUMAR
Keyword(s):  
Water Samples ◽  
Suspended Solids ◽  
Total Dissolved Solids ◽  
Tolerance Limit ◽  
Chemical Condition ◽  
Yamuna River ◽  
Dissolved Solids ◽  
Time Period ◽  
Physico Chemical ◽  
Almost All

An attempt has been made to study the Physico-chemical condition of water of Yamuna River at Gokul Barrage, Mathura, (UP). The time period of study was July 2015 to June 2016. Three water samples were selected from different sites in each month for study. The parameters studied were Temperature, Turbidity, pH, DO, BOD, COD, Total Dissolved Solids and Suspended Solids. Almost all the parameters were found above the tolerance limit.

Experiments on high rate effluent filtration in the Netherlands

1998 ◽  
Vol 38 (3) ◽  
pp. 127-134
Author(s):  
Jaap H. J. M. van der Graaf ◽  
Arjen F. van Nieuwenhuijzen
Keyword(s):  
Wastewater Treatment ◽  
The Netherlands ◽  
Suspended Solids ◽  
Practical Experience ◽  
High Rate ◽  
Treated Water ◽  
Low Concentrations ◽  
Wastewater Treatment Effluent

As yet, filtration of wastewater treatment effluent has not been practised in the Netherlands. The main objections were the expected high costs. In order to gain practical experience an investigation programme studied the applicability and optimization of effluent filtration. Especially multi-layer filtration with the addition of ironchloride seemed to be very effective. Very low concentrations of suspended solids and phosphorus were achieved, even at high filtration rates (up to 30 m/h). This leads to an impressive reduction of expected costs, down to Dfl. 0.02/m3 (treated water).

Small-volume vitrification and rapid warming yield high survivals of one-cell rat embryos in cryotubes

2021 ◽  
Author(s):  
Yasuyoshi Fukuda ◽  
Misako Higashiya ◽  
Takahiro Obata ◽  
Keita Basaki ◽  
Megumi Yano ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Small Volume ◽  
Sucrose Solution ◽  
High Concentration ◽  
Rat Embryos ◽  
Low Concentrations ◽  
Intracellular Ice Formation ◽  
Intracellular Ice ◽  
Warming Rate ◽  
Very High

Abstract To cryopreserve cells, it is essential to avoid intracellular ice formation during cooling and warming. One way to achieve this is to convert the water inside the cells into a non-crystalline glass. It is currently believed that to accomplish this vitrification, the cells must be suspended in a very high concentration (20–40%) of a glass-inducing solute, and subsequently cooled very rapidly. Herein, we report that this belief is erroneous with respect to the vitrification of one-cell rat embryos. In the present study, one-cell rat embryos were vitrified with 5 μL of EFS10 (a mixture of 10% ethylene glycol, 27% Ficoll, and 0.45 M sucrose) in cryotubes at a moderate cooling rate, and warmed at various rates. Survival was assessed according to the ability of the cells to develop into blastocysts and to develop to term. When embryos were vitrified at a 2,613 °C/min cooling rate and thawed by adding 1 mL of sucrose solution (0.3 M, 50 °C) at a warming rate of 18,467 °C/min, 58.1 ± 3.5% of the EFS10-vitrified embryos developed into blastocysts, and 50.0 ± 4.7% developed to term. These rates were similar to those of non-treated intact embryos. Using a conventional cryotube, we achieved developmental capabilities in one-cell rat embryos by rapid warming that were comparable to those of intact embryos, even using low concentrations (10%) of cell-permeating cryoprotectant and at low cooling rates.

Treatment of tunnel wash water and implications for its disposal

2014 ◽  
Vol 69 (10) ◽  
pp. 2029-2035 ◽  
Author(s):  
M. Hallberg ◽  
G. Renman ◽  
L. Byman ◽  
G. Svenstam ◽  
M. Norling
Keyword(s):  
Traffic Safety ◽  
Urban Areas ◽  
Suspended Solids ◽  
Treatment Plant ◽  
Particulate Material ◽  
Wash Water ◽  
Polluted Water ◽  
Solids Concentration ◽  
Low Concentrations ◽  
Road Tunnels

The use of road tunnels in urban areas creates water pollution problems, since the tunnels must be frequently cleaned for traffic safety reasons. The washing generates extensive volumes of highly polluted water, for example, more than fivefold higher concentrations of suspended solids compared to highway runoff. The pollutants in the wash water have an affinity for particulate material, so sedimentation should be a viable treatment option. In this study, 12 in situ sedimentation trials were carried out on tunnel wash water, with and without addition of chemical flocculent. Initial suspended solids concentration ranged from 804 to 9,690 mg/L. With sedimentation times of less than 24 hours and use of a chemical flocculent, it was possible to reach low concentrations of suspended solids (<15 mg/L), PAH (<0.1 μg/L), As (<1.0 μg/L), Cd (<0.05 μg/L), Hg (<0.02 μg/L), Fe (<200 μg/L), Ni (<8 μg/L), Pb (<0.5 μg/L), Zn (<60 μg/L) and Cr (<8 μg/L). Acute Microtox® toxicity, mainly attributed to detergents used for the tunnel wash, decreased significantly at low suspended solids concentrations after sedimentation using a flocculent. The tunnel wash water did not inhibit nitrification. The treated water should be suitable for discharge into recipient waters or a wastewater treatment plant.

Biolixiviation des métaux lourds et stabilisation des boues d'épuration : essai en bioréacteur opéré en mode cuvée

1993 ◽  
Vol 20 (1) ◽  
pp. 57-64 ◽  
Author(s):  
R. D. Tyagi ◽  
J. F. Blais ◽  
N. Meunier ◽  
D. Kluepfel
Keyword(s):  
Heavy Metals ◽  
Sewage Sludge ◽  
Suspended Solids ◽  
Elemental Sulfur ◽  
Batch Reactor ◽  
Fecal Coliforms ◽  
Sludge Stabilization ◽  
Sludge Digestion ◽  
Batch Time ◽  
Phosphorus And Potassium

A biological process of heavy metals solubilization and sewage sludge stabilization was studied in a batch reactor of 30-L capacity. The acclimatized leaching microflora was composed of two major groups of thiobacilli: less acidophilic and acidophilic. A batch time of 10 days allows a substantial metal solubilization: cadmium (100%), copper (80%), manganese (80%), nickel (46%), and zinc (100%). The bioleaching process also causes a significative decrease in sludge total suspended solids (25%) and volatile suspended solids (32%), and a considerable reduction (under the detection limit of 10 cfu∙mL−1) of indicator bacteria (total coliforms, fecal coliforms, fecal streptococci). After filtration or centrifugation of the leached sludge, the solubilized metals were precipitated by lime neutralization. The phosphorus and potassium sludge contents were not affected by bioleaching process. These results indicate that the process of sludge digestion and metal leaching can be conducted in parallel in the same reactor. Key words: sewage sludge, heavy metals, bioleaching, stabilization, thiobacilli, elemental sulfur.

scholarly journals Validation of SCIAMACHY limb NO<sub>2</sub> profiles using solar occultation measurements

2011 ◽  
Vol 4 (4) ◽  
pp. 4753-4800
Author(s):  
R. Bauer ◽  
A. Rozanov ◽  
C. A. McLinden ◽  
L. L. Gordley ◽  
W. Lotz ◽  
...  
Keyword(s):  
The Past ◽  
Middle Latitudes ◽  
Solar Occultation ◽  
Time Period ◽  
Vertical Distributions ◽  
Global Coverage ◽  
Scanning Imaging ◽  
Diurnal Effect ◽  
Better Than ◽  
Balloon Measurements

Abstract. The increasing amounts of reactive nitrogen in the stratosphere necessitates accurate global measurements of stratospheric nitrogen dioxide (NO2). Over the past decade, the SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) instrument on ENVISAT (European Environmental Satellite) has been providing global coverage of stratospheric NO2 every 6 days, which is otherwise difficult to achieve with other systems (e.g. balloon measurements, solar occultation). In this study, the vertical distributions of NO2 retrieved from limb measurements of the scattered solar light from the SCIAMACHY instrument are validated using NO2 products from three different satellite instruments (SAGE II, HALOE and ACE-FTS). The retrieval approach, as well as the sensitivity of the SCIAMACHY NO2 limb data product are discussed, and the photochemical corrections needed to make this validation feasible, as well as the chosen collocation criteria are described. For each instrument, a time period of two years is analyzed with several hundreds of collocation pairs for each year and instrument. The agreement between SCIAMACHY and each instrument is found to be better than 10 % between 22–24 km and 40 km. Additionally, NO2 amounts in three different latitude regions are validated individually, with considerably better agreements in high and middle latitudes compared to tropics. Differences with SAGE II and ACE-FTS below 20 km are consistent with those expected from the diurnal effect.

International Real Estate Review

2017 ◽  
Vol 20 (1) ◽  
pp. 1-21
Author(s):  
Greg MacKinnon ◽  
◽  
Jon Spinney ◽  
Keyword(s):  
Real Estate ◽  
Equity Market ◽  
Portfolio Performance ◽  
Real Estate Investment ◽  
Construction Techniques ◽  
Time Period ◽  
High Volatility ◽  
Weighted Portfolio ◽  
Portfolio Design ◽  
Better Than

We examine the market for U.S. equity real estate investment trusts (REITs) for evidence of the volatility effect, in which low volatility stocks tend to outperform high volatility ones, as has been found in the general equity market by prior research. While there is some evidence of a volatility effect in the first ten years of the sample, this disappears in a more recent time period. Furthermore, we test the efficacy of low risk portfolio construction techniques and find that none perform any better than a market cap weighted portfolio ¡V although they are also no worse ¡V over any of the time periods examined. Thus, there is no evidence that using a risk-based portfolio design that emphasizes low volatility would improve portfolio performance for a REIT allocation.

scholarly journals Provide a New Encryption Algorithm for Medical Images and Evaluate the Proposed Algorithm

2019 ◽  
Vol 8 (1) ◽  
pp. 2
Author(s):  
Mehdi Lotfi ◽  
Hossein Kheiri ◽  
Azizeh Jabbari
Keyword(s):  
Differential Equations ◽  
Chaotic Systems ◽  
Medical Information ◽  
Medical Images ◽  
Encryption Algorithm ◽  
Key Generation ◽  
Time Period ◽  
Key Space ◽  
Encryption And Decryption ◽  
Very High

Introduction:  In this paper, an encryption algorithm for the security of medical images is presented, which has extraordinary security. Given that the confidentiality of patient data is one of the priorities of medical informatics, the algorithm can be used to store and send medical image.Material and Methods:  In this paper, the solutions of chaotic differential equations are used to generate encryption keys. This method is more than other methods used in encoding medical images, resistant to statistics attacks, low encryption and decryption time and very high key space. In the proposed algorithm, unlike other methods that use random key generation, this method uses the production of solutions of the chaotic differential equations in a given time period for generating a key. All simulations and coding are done in MATLAB software.Results:   Chaotic Differential Equations have two very important features that make it possible to encode medical images. One is the unpredictability of the system's behavior and the other is a severe sensitivity to the initial condition.Conclusion: These two features make the method resistant to possible attacks to decode the concept of synchronization chaotic systems. Using the results of the method, medical information can be made safer than existing ones.

scholarly journals Image Hiding Using QR Factorization And Discrete Wavelet Transform Techniques

2021 ◽  
Vol 6 (2) ◽  
pp. 72-81
Author(s):  
Reham Ahmed El-Shahed ◽  
◽  
Maryam Al-Berry ◽  
Hala Ebied ◽  
Howida A. Shedeed ◽  
...  
Keyword(s):  
Data Security ◽  
Color Image ◽  
Simple Algorithm ◽  
Qr Factorization ◽  
Discrete Wavelet ◽  
Huge Amount ◽  
Image Hiding ◽  
Media Applications ◽  
Very High ◽  
Better Than

Steganography is one of the most important tools in the data security field as there is a huge amount of data transferred each moment over the internet. Hiding secret messages in an image has been widely used because the images are mostly used in social media applications. The proposed algorithm is a simple algorithm for hiding an image in another image. The proposed technique uses QR factorization to conceal the secret image. The technique successfully hid a gray and color image in another one and the performance of the algorithm was measured by PSNR, SSIM and NCC. The PSNR for the cover image was in the range of 41 to 51 dB. DWT was added to increase the security of the method and this enhanced technique increased the cover PSNR to 48 t0 56 dB. The SSIM is 100% and the NCC is 1 for both implementations. Which improves that the imperceptibility of the algorithm is very high. The comparative analysis showed that the performance of the algorithm is better than other state-of-the-art algorithms

scholarly journals The Upsurge and Impact of COVID 19 in India: Health Issues and Remedial Measures

2021 ◽  
pp. 28-34
Author(s):  
Kanchi Isswani
Keyword(s):  
Sudden Increase ◽  
The Novel ◽  
Health Issues ◽  
Public Places ◽  
Frontline Workers ◽  
Time Period ◽  
Essential Services ◽  
Novel Coronavirus ◽  
Major Decision ◽  
Better Than

The novel Coronavirus was something that nobody was prepared for. It was that part of the syllabus which was always neglected. The contagious disease which started in the Wuhan region of China had started to settle in various parts of the World. The outbreak of this disease has reached such a huge number that all the countries witnessed lockdown in some form or the other. Some people have witnessed destruction of mankind while some have even leisured this time to their fullest but as it has been always said “Prevention is better than cure”. Prevention of covid 19 in all the nations was one of the major steps which was taken in the year 2020. In India it all started in the year of 2019 December when the first ever case of covid 19 was reported in the state of Kerala followed by Rajasthan, Maharashtra and Delhi. Following such a situation and then sudden increase in the no of cases all over the country a major decision was taken that was of Complete lockdown excluding the emergency and essential services. Before taking the step of lockdown, as a gesture of respect to the frontline workers, government of India announced Tali Bajao movement. In the period of lockdown Certain norms were even made mandatory that were wearing a mask, maintenance of hand sanitation and following social distancing of 1.5 meters in public places. All the educational institutes and teachings were even suspended during the time period of lockdown as it could have become a hub for the virus to spread. With time, the restrictions which were laid down in lockdown were started to be reduced in the phase wise manner and finally India noticed its very first Unlock period. In all this scenario mankind has dealt with various situations and have emerged to be a better person. All these steps were crucial to control the spread of Novel Coronavirus and prevention from the already spread cases.

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