scholarly journals The study of the effectiveness of coagulants and white sludge in the process of dephosphotation of municipal wastewater

2020 ◽  
Vol 193 ◽  
pp. 02001
Author(s):  
Tamara Gorbacheva ◽  
Dmitriy Mayorov ◽  
Yuri Velyaev ◽  
Yar Zar Htun
Keyword(s):  
Metal Oxide ◽  
Municipal Wastewater ◽  
Permissible Exposure Limit ◽  
Urban Sewage ◽  
Exposure Limit ◽  
Degree Of Purification

The results of the test coagulation of clarified wastewater of urban sewage facilities are presented in this work. A dose of aluminum and iron-containing coagulants in terms of metal oxide (Me2O3 ) was used as a parameter for comparison of the efficiency of reagent removal of phosphorus from wastewater. It was shown that the uses of any of the selected coagulants make it possible to bring the degree of purification of municipal effluents to the requirements of fishery co-op permissible exposure limit at the stage of simultaneous subsidence, while the best efficiency results are obtained for an aluminum oxychloride coagulant.

scholarly journals The exposure of working environment noise in the agricultural service workplaces

2009 ◽  
Vol 55 (No. 2) ◽  
pp. 69-75 ◽  
Author(s):  
M. Šístková ◽  
A. Peterka
Keyword(s):  
Human Health ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Pressure Level ◽  
Working Environment ◽  
Service Workers ◽  
Permissible Exposure Limit ◽  
Noise Characteristics ◽  
Exposure Limit ◽  
Environment Noise

The noise belongs to the leading harmful factors which pollute the environment and negatively influences human health. An overview measurement concerning the noise characteristics has been done in agricultural service workplaces. The sound pressure level has been measured and the length of the workers exposition has been elicited in each workplace. The obtained data has proved that some agricultural service workers have been exposed to a noise above the permissible exposure limit.

Assessment of the Effects of Ornamental Wetland Polyculture Combinations on Urban Sewage Treatment

2021 ◽  
Author(s):  
Min Wang ◽  
Yujue Zhou ◽  
Lin Xiang ◽  
Xiaoyang Ke ◽  
Hui Zhang ◽  
...  
Keyword(s):  
Plant Diversity ◽  
Municipal Wastewater ◽  
Plant Biomass ◽  
Removal Rate ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Wetland Plant ◽  
Urban Sewage ◽  
Thalia Dealbata ◽  
Cyperus Alternifolius

Abstract Previous studies have shown that wetland plants can treat wastewater in a cost-effective and sustainable way, however, the studies on the performance of ornamental wetland plant diversity in treating urban sewage were scarce. Therefore, this study was conducted to assess and select wetland polyculture combination that was effective in urban sewage treatment in subtropical areas. We formed five combinations out of six ornamental wetland plant species including Thalia dealbata, Cyperus alternifolius, Iris pseudacorus, Lythrum sastlicaria, Nymphaea tetragona, and Zantedeschia aethiopica. The growth state and removal effects of each plant combination were systematically measured and assessed. The results indicated all the combinations exhibited remarkable total nitrogen (TN), total phosphorus (TP), ammonium nitrogen (NH­4+-N), and chemical oxygen demand chromium (CODcr) removal rate of 70.75%-77.67%, 63.86%-73.71%, 69.73%-76.85%, and 57.28%-75.69%, respectively. Additionally, pH was reduced to 7.54-8.00 in the sewage. The purification effect reached the best during 30-36th day. The comprehensive assessment showed the mixture of Thalia dealbata + Cyperus alternifolius, closely followed by Thalia dealbata + Cyperus alternifolius+ Lythrum sastlicaria, was highly effective at extracting various pollutants, and both of them could be used as favorable combinations to convert eutrophication and purify municipal wastewater. Linear regression showed that TP, TP, NH­4+-N, and CODcr. were significantly related to plant biomass, indicating that plant biomass essential indicator for screening purification plants. Our study highlighted the importance of plant diversity in biological wastewater treatment, however the competition between plants was suggested to take into consideration in future studies.

The Efficiency of Biological Total Phosphorus Removal Process

2019 ◽  
Vol 70 (6) ◽  
pp. 1920-1923
Author(s):  
Cristian Muntenita ◽  
Carmelia Mariana Dragomir Balanica ◽  
Aurel Gabriel Simionescu ◽  
Silvius Stanciu ◽  
Camelia Lacramioara Popa
Keyword(s):  
Total Phosphorus ◽  
Phosphorus Removal ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Municipal Wastewater Treatment ◽  
Yearly Average ◽  
Effluent Discharge ◽  
Municipal Wastewater Treatment Plants ◽  
Biological Methods ◽  
Degree Of Purification

This article investigates the efficiency of phosphorus removal in the municipal wastewater treatment plants in five counties of Romania from 2013 to 2017. This study focused on evaluation of the performance of phosphorus elimination using biological methods in order to respect the admissible effluent discharge limits. The yearly average of inflow total phosphorus varies from 3.64 mg/L to 4.22 mg/L comparing with 1.02 mg/ L and 1.59 mg/L the average of outflow. Chemical and biological methods are utilized to remove phosphorus. The efficiency of the numerous process available for the phosphorus removal is quite inadequate by comparing the effluent degree of purification and the removal cost.

Permissible Exposure Limit (PEL)

2016 ◽  
Author(s):  
John H. Duffus ◽  
Monica Nordberg ◽  
Douglas M. Templeton
Keyword(s):  
Permissible Exposure Limit ◽  
Exposure Limit

scholarly journals Pulmonary Evaluation of Permissible Exposure Limit of Syntroleum S-8 Synthetic Jet Fuel in Mice

2009 ◽  
Vol 109 (2) ◽  
pp. 312-320 ◽  
Author(s):  
Simon S. Wong ◽  
Alana Thomas ◽  
Brian Barbaris ◽  
R. Clark Lantz ◽  
Mark L. Witten
Keyword(s):  
Jet Fuel ◽  
Synthetic Jet ◽  
Permissible Exposure Limit ◽  
Exposure Limit

scholarly journals Distribution of human fecal marker GB-124 bacteriophages in urban sewage and reclaimed water of São Paulo city, Brazil

2017 ◽  
Vol 16 (2) ◽  
pp. 289-299 ◽  
Author(s):  
Tatiana Prado ◽  
Antônio de Castro Bruni ◽  
Mikaela Renata Funada Barbosa ◽  
Vilma Marques Santos Bonanno ◽  
Suzi Cristina Garcia ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Municipal Wastewater ◽  
Low Cost ◽  
Reclaimed Water ◽  
Sao Paulo ◽  
São Paulo ◽  
Virus Removal ◽  
Urban Sewage ◽  
Viral Marker ◽  
Activated Sludge Processes

Abstract Bacteriophages infecting Bacteroides fragilis GB-124 have been described as potential markers of human fecal contamination in water sources. The aim of this study was to evaluate the occurrence of GB-124 phages in raw sewage, secondary effluents and reclaimed water of the São Paulo city using a low-cost microbial source tracking method. Samples were collected monthly from April 2015 to March 2016 in four municipal wastewater treatment plants that operate with activated sludge processes followed by different tertiary treatments (sand-anthracite filtration, membrane bioreactor/reverse osmosis) and final chlorination. GB-124 phages were detected in 100% of the raw sewage samples, with viral loads varying from 7.5 × 103 to 1.32 × 106 PFU/L. Virus removal efficiency in activated sludge processes ranged from 1.89 to 2.31 log10. Frequencies of phage detection were lower in reclaimed water samples (0–22.2%). The results indicated that GB-124 phage could be a complementary low-cost viral marker for the detection of human fecal pollution in waters impacted with urban sewage in this region. However, the datasets of tertiary effluents resulted in several samples with concentrations below the detection limit (DL ≤1 PFU/mL) suggesting the need to obtain analytical methods with lower DL for greater accuracy of negative results.

PSXIII-18 The effect of lead on alkaline phosphatase serum activity in European carp

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 434-435
Author(s):  
Polina D Bokhan ◽  
Polina A Polistovskaia ◽  
Larisa Y Karpenko ◽  
Abram I Enukashvili ◽  
Alesya A Bakhta ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Russian Federation ◽  
Lead Acetate ◽  
Control Group ◽  
Acetate Concentration ◽  
Permissible Exposure Limit ◽  
Serum Activity ◽  
Exposure Limit ◽  
The Russian Federation ◽  
Experimental Group

Abstract The aim of this research is to assess the toxic influence of heavy metals in fish. This study was intended to analyze alkaline phosphatase (AP) serum activity under the influence of various lead concentrations in European carp. AP is involved in the dephosphorylation processes and is an important indicator of liver and skeleton tissue metabolism. When exposed to heavy metals, a change in the activity of this enzyme can be observed. In this experiment 3 groups of fish (European carp) were formed, 10 fish in each group: control group; 1-experimental group – fish were contained in water with 0.06 mg/l lead acetate concentration (upper threshold level than fishery waters permissible exposure limit according to the laws of the Russian Federation); 2-experimental group – fish were contained in water with 0.6 mg/l lead acetate concentration (10 times higher than fishery waters permissible exposure limit according to the laws of the Russian Federation). Exposure time was 4 hours. The blood samplings were taken from heart by syringe and placed in dry test tubes. After samplings centrifugation in non-hemolysed serum samples AP activity was assessed. The study revealed the decreasing trend of AP serum activity by 1.08% (21.89±0.24 IU/l) in 1-experimental group in compare with control group (22.13±0.78 IU/l). In case where the lead acetate concentration were 10 times higher than fishery waters permissible exposure limit were meaningful decreasing of AP activity (P ≤ 0.05) by 66.23% (17.42±0.63 IU/l) accordingly in 2-experimental group in compare with control group. In conclusion, a statistically significant decrease in the AP activity in fish blood serum was found after acetate concentration 10 times higher than the permissible exposure limit in fishery waters, according to the laws of the Russian Federation. We can suppose that the activity of this enzyme is the reason for the inhibitory effect of lead on liver tissue.

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