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Optimization of Aeration for Improving Performance of Hospital Wastewater Treatment Plant Full text
2023
Zahra Hezarian | Ehsan Derikvand | Afshin Takdastan
The present descriptive cross-sectional study was conducted by altering the type of blowers in the wastewater treatment system of Abuzar hospital in Ahvaz during the first and second quarters (6 months). In every month, inlet raw wastewater, aeration tank one, and effluent were sampled in one week (Saturday-Friday), which resulted in harvesting a total of 42 samples. Then, they were assessed based on the techniques provided in the book entitled "standard methods for evaluating water and wastewater", and data were evaluated through employing statistical analyses. The average removal efficiency of total and organic phosphorus, phosphate, and ammonia in the effluent was respectively determined 46.47, 34.45, 18.14, and 68.49 before starting up a new aeration system, which reached 69.36, 76.21, 65.09, and 96.53 during the second period, respectively. In addition, the average concentration of nitrate varied from 21.79 to 44.11 mg/l, while that of nitrite changed from 0.04 to 0.03 mg/l. Further, an increase (39.19 to 67.19%) was observed in the average nitrogen removal efficiency in effluent. Based on the results, EAAS process was efficient in eliminating nitrogen and phosphorus by using the helicoidal pumps of aeration blowers and regulating aeration rate. Thus, aeration plays an effective role in activated sludge systems despite the microorganism diversity in aeration tank sludge. The produced effluent was consistent with Iran national standards in terms of the parameters under study, especially phosphorus and nitrogen, and can be discharged into the environment.
Show more [+] Less [-]Zoning and modeling of energy consumption in human settlements and explaining the effective components in the design of green buildings (Case study: Mashhad) Full text
2023
Najiyeh Abavisani Joghtaee | Amir Farajollahi Rod | Mansour Yeganeh
The purpose of this study is to achieve the effective components and criteria in the design of green residential settlements with an environmental protection approach in Mashhad. The research method is applied and in terms of implementation is descriptive-analytical. Using the TM sensor and LANDSAT satellite, satellite images of the study area were prepared and modeled by superimposing data related to energy consumption through GIS tools and Arcview software to final synthesis and mapping. Then, using the opinions of experts to extract and prioritize the appropriate components and criteria from each of the mentioned systems. Data were analyzed by structural equation method with least squares approach and Smart - PLS2 software was used for final analysis. Then, after explaining the components and criteria, according to the available data, the optimal limit (10% -20%) for 10 components was proposed as a scenario. Then modeling was done through Design Builder software. The results showed that a total of 4 categories of macro variables have been identified as the main components affecting energy consumption, which are: "management", "environmental performance", "economic performance" and "social performance" variables, all of which have divergent validity. Also, 11 topics and 61 criteria were extracted and explained as components for assessing the sustainability of residential buildings. Finally, it was found that with the implementation of energy optimization strategies, the heating system will be reduced by 36%, the cooling system energy by 41% and the total cooling and heating energy by 38% compared to the base state.
Show more [+] Less [-]Investigation of civil responsibility for the spread of environmental pollution caused by the Coronavirus pandemic Full text
2023
Shadi Shoghi Beygi | S.Ali Jozi | Mojtaba Zamani
The most important objectives of the present study include finding a legal solution to prevent the spread of coronavirus, compensation for damages caused by the negligence of human factors, determining the basis for this responsibility, and the rate of compensation for these damages. The present study, through library and field studies, made it possible to compensate for the damage caused by the spread of coronavirus infections. Pollution caused by a human is one of the most important environmental law challenges. Neglect of the human factor has caused losses due to the spread of this disease. In the present study by preparing a researcher-made questionnaire, the opinion of lawyers specializing in the field of civil responsibility was also inquired. The results of the research show that by resorting to the "risk theory" and the "fault assumption" basis, the rights of the victims of the Coronavirus can be better secured. At present, legal systems are not sufficiently determined to compensate the victims of the Coronavirus. While environmental jurists believe that strict rules and regulations should be applied to combat the spread of coronavirus infection and to impose compensation for damages caused by negligence in observing health standards on its human factors. In Iran, several juridical and legal rules are a good basis for preventing the spread of coronavirus and human infections.
Show more [+] Less [-]Measuring noise pollution from sports events in urban environments (case study: Azadi stadium) Full text
2023
Farzaneh Taghavi Baghan | Seyed Mostafa Tayebi Sani | Nabiollah Ider | Mozhdeh Khajoo
Sound pollution is known as one of the main disturbances in urban environments. The purpose of this study is to measure the sound level during sports competitions in the vicinity of settlements. For this purpose, Azadi Sports Complex was selected as the largest sports space in the IRAN and the measurements were performed cross-sectional and in two different times, which included days without sports competition and after the end of the sports competition. Measurements were used 5 times by KIMO-DB100. All measurements were made to determine the sound pressure level in network A. The mean data (Leq) was the basis for drawing the maps. To do this, the pattern of changes was entered into the Arc map software and based on the Inverse Distance Weighting method. The results showed that the minimum sound level on the day without exercise was 50 dB and the maximum sound level measured at this time was 80 dB. On the day of the race, the minimum and maximum sound levels were 55 dB and 95 dB, respectively. On a non-racing day, large sections of the study range have sound levels of 50-65 dB, indicating relative calm and compliance with outdoor sound standards. However, on the day of the match and after the spectators left the stadium, none of the sound level stations showed less than 75 dB. This situation continues for about 3 hours after the end of the game and until the study area of spectators and their cars is completely emptied.
Show more [+] Less [-]Investigation of wet spraying system to control dust pollution in mines (A case study ) Full text
2023
Mahmoud Makkiabadi | Sara Yaghoobi | Mohammad Saleh Haj Mohammadi
Industrial dust has a significant effect on the environment of mines, which leads to an increase in illness among workers. To decrease the impact of dust on the climate, a wet spraying system is useful for controlling dust in mining companies. In this paper, by using the wet (water) spraying system, dust control in the area of the crusher and pellet plant (discharge tower) has been investigated by Goharzamin Iron Ore company. Goharzamin Iron Ore company has an essential role producing of steel in Iran. There are a 15 million tons gyratory crusher, three iron concentrate plants with an annual capacity of 6 million tons, and a pelletizing plant with annual capacity of 5 million tons. The dust was controlled in the gyratory crusher area of Goharzamin Iron Ore company by using a wetting spraying system. Results showed that the rates of PM10 for the east, west, north and south sides of the gyratory crusher and also the center of this system are equal 851.2, 647.5, 643.9 and 781.2, and 1116.3 μg/m3, respectively. Foremore, after turning on the wet spraying system in this area, these values are reduced to 128.3, 112.8, 115.9, 123.7, and 189.9 μg/m3, respectively. The results showed that the water spray system in the gyratory crusher area reduced the PM2.5 (Particulate matter) and PM10 particles by 67% and 80%, respectively.
Show more [+] Less [-]Investigating the role of origami algorithm in facades of high-rise buildings to reduce visual pollution and improve urban landscape quality Full text
2023
Tabbasom Tabasi | Amir Farajolahi Rod | Vahid Ahmadi | Hamid Reza Shoaei
The present study was conducted to identify and prioritize origami components affecting facades of high-rise buildings to explain the role of origami algorithm in improving urban landscape quality and reducing visual pollution. The research had an exploratory nature, and used the method of descriptive-survey data analysis. The research design was carried out in three steps, documentary analysis, Delphi survey and semiotic analysis. A panel of experts (n = 15) was considered as specialists in urban planning, architecture and urban design. Data were analyzed by statistical tests, SPSS-22 software and MAXQDA 2020 software. A hypothetical model of high-rise building made in RHINO software using Grasshopper plugin was applied for simulation. The results of the questionnaires revealed the effects of 18 components on the facade of high-rise buildings and also 12 components on the improvement of urban landscape quality. The findings indicated a correlation between overall dimensions of origami algorithm and urban landscape quality, and showed that the components of ârepetitionâ, âdetailsâ, âgeometryâ and ârhythmâ were most related to the origami algorithm, thereby highlighting the strong impact of the origami algorithm on improving urban landscape quality. According to the simulation results, among the components affecting urban landscape quality, âView compositionâ had the largest contribution with the correlation coefficient of 130, followed by âColorâ and âBalance and symmetryâ with the coefficients of 120. The end of this classification included the component âposition of openingsâ with the coefficient of 2.
Show more [+] Less [-]Influence of waves on the three-dimensional distribution of plastic in the ocean Full text
2023
Bajon, Raphael | Huck, Thierry | Grima, Nicolas | Maes, Christophe | Blanke, Bruno | Richon, Camille | Couvelard, Xavier
The world's oceans are facing plastic pollution, 80 % of which of terrestrial origin flowing from the mismanaged waste of coastal populations and from river discharge. To study the fate of this pollution, the three-dimensional trajectories of neutral plastic particles continuously released for 24 years according to realistic source scenarios are computed using currents from a global ocean-wave coupled model at resolution and from a reference ocean-only model. These Lagrangian simulations show that neutral particles accumulate at the surface in the subtropical convergence zones from where they penetrate to about 250 m depth and strongly disperse over 40∘ of latitude. About 5.3 % of the particles remain at the surface with the wave-coupled model currents, whereas only 2 % for the uncoupled model, with some modulation in the location of the convergence zones. Increased surface retention results from upward vertical velocities induced by widespread divergence of waves-induced Stokes transport in the surface layers.
Show more [+] Less [-]Pollution and ecological risk assessments for heavy metals in coastal, river, and road-deposited sediments from Apia City in Upolu Island, Samoa Full text
2023
Jeong, Hyeryeong | Ra, Kongtae
This study was the first to investigate the pollution and ecological risks of heavy metals in coastal, river/stream and road-deposited sediments (RDS) from Apia in Samoa. Cr and Ni concentrations in sediment samples were higher than those of other metals. River sediments and RDS had relatively high EF values around the intensive commercial areas, with a moderate to significant enrichment of Cu, Zn, Cd, and Pb. The results indicate that Cr and Ni have a natural origin from volcanic parent materials, while Cu, Zn, Cd, and Pb originated from anthropogenic activities, such as traffic emissions and the discharge of municipal wastewater. The assessments of pollution and ecological risk revealed that coastal sediments adjacent to the river are anthropogenically contaminated and present a moderate ecological risk. This study demonstrates that metals that have accumulated in the urban impermeable layer and river/stream bed have flowed into the coastal environment through runoff.
Show more [+] Less [-]Phenology of scyphozoan jellyfish species in a eutrophication and climate change context Full text
2023
Fernández-alías, Alfredo | Molinero, Juan Carlos | Quispe-becerra, Jhoni Ismael | Bonnet, Delphine | Marcos, Concepción | Pérez-ruzafa, Angel
The uprising interest in gelatinous zooplankton populations must cope with a lack of robust time series of direct abundance observations in most of the ecosystems because of the difficulties in sampling small, fragile organisms, and of the dismissal of jellyfish as a nuisance. Most of the hypotheses about their dynamics are built on a few species and ecosystems and extended to the whole group, but the blooms are registered mainly for the members of the Class Scyphozoa that dwell in temperate, shallow waters. Within the scyphozoans, our knowledge about their phenology relies mainly on laboratory experiences. Here we present a long-term analysis of the phenology and life cycle of three scyphozoan species in an ecosystem affected by eutrophication in a climate change context. We have found that the phenology is directed by temperature, but not modified by different thermal and ecological regimes.
Show more [+] Less [-]The French Mussel Watch: More than two decades of chemical contamination survey in Mediterranean coastal waters Full text
2023
Briand, Marine | Herlory, Olivier | Briant, Nicolas | Brach-papa, Christophe | Boissery, Pierre | Bouchoucha, Marc
Active biomonitoring of chemical contamination (e.g., Cd, Hg, Pb, DDT, PCB, PAH) in French Mediterranean coastal waters has been performed for more than two decades. This study aimed at presenting the current contamination in 2021 and the temporal evolution of concentrations from 2000. Based on a relative spatial comparison, low concentrations were measured in 2021 at most sites (>83 %). Also, several stations with moderate to high levels were highlighted in the vicinity of major urban industrial centers (e.g., Marseille, Toulon) and near river mouths (e.g., Rhône, Var). Over the last 20 years, no major trend was revealed, mostly, especially for the relative high-level sites. This likely constant contamination over time, plus slight increases of metallic elements at a few sites, still raise questions on the efforts that remain to be made. The decreasing trends of organic compounds, in particular PAH, provide evidence of the efficiency of some management actions.
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