Effects Of Pollution Levels Research Articles

Changes in Nitrogen and Humus During Aerobic Composting Under Antibiotic Composite Pollution

Antibiotic residues have significantly effects on aerobic composting process. This study was targeted at antibiotic composite pollutants (e.g., sulfanilamides, tetracyclines, and quinolones) and probed into the effects of pollution levels on aerobic composting. With higher initial antibiotic concentrations, the NH4+ –N and NO3− –N concentrations at the end of composting were higher, but TN content decreased, which may be due to the inhibition effects of antibiotics on nitrogen-fixing bacteria and thus were unfavorable for nitrogen accumulation. Antibiotic pollution obviously delayed composting maturity, and the antibiotics at initial concentration above 306.12 mg/kg were significantly toxic to seeds. Analysis of structural changes in dissolved organic matter (DOM) showed the humification after treatments CK and AT100 mainly occurred at the high-temperature stage (day 2–14) and later lower-temperature maturity stage (day 21–36). Humification after treatment AT300 mainly happened at the high-temperature stage (day 2–14), and that in AT600 mainly occurred at the early temperature rise and high-temperature stage (day 2–7). This study comprehensively evaluated the effect of antibiotic composite pollution on the maturity of aerobic compost, and provided a theoretical basis for the treatment of antibiotic composite pollution materials in practical production.

Effects of Multiple-Metal-Compound Contamination on the Soil Microbial Community in Typical Karst Tea Plantations

In this study, the effects of pollution levels and heavy metal pollution on soil microbial diversity in karst tea plantations are reported. Four tea plantations from plateau hills, under forests, by lakesides and on steep slopes in the South China karst were used as research regions. Soil samples were taken from these tea plantations, the soil heavy metals Cd, Cr, Pb, Zn, Ni and Cu were tested using inductively coupled plasma-mass spectrometry, and Hg and As were tested via atomic fluorescence spectrometry. The soil microbes were analyzed via high-throughput sequencing technology. Heavy metal pollution was evaluated via the single factor index and pollution load index, and the correlation between soil heavy metals and the microbial community was analyzed via SPSS 18.0 and Canoco 5.0 software. The results showed that the studied tea plantation soils were greatly polluted by the heavy metals, Cd and Hg, to a low to moderate degree. The comprehensive pollution of multiple heavy metals occurred only in lakeside tea plantations, in which pollution reached a low degree. It is also suggested that Hg and Cd were the major contributors, followed by Cu. The soil microbial diversity in soil samples from lakeside tea plantations was the highest; however, the discrepancy in its dominant species composition was also the highest. When the pollution load index was close to 0.6, the microbial diversity decreased sharply. Afterward, the diversity and heterogeneity generally gently increased, and the dominant composition was more obvious. These results reveal that the impact of heavy metal pollution on soil microbial diversity was not very distinct, but the impact on the dominant microbial community composition was obvious. In addition, the heavy metals, Cd, Hg and Cu, were the key factors that impacted the soil microbial community composition.

Climate Change Effects on Carbonation Process: A Scenario-Based Study

Using a mathematical model of concrete carbonation that describes the variation in porosity as a consequence of the involved chemical reactions, we both validated and calibrated the related numerical algorithm of degradation. Once calibrated, a simulation algorithm was used as a forecasting tool for predicting the effects on the porosity of concrete exposed to increasing levels of CO2 emissions, as well as to rising temperatures. Taking into account future projections of environmental modifications deriving from climate changes, some scenarios were produced numerically by the mathematical algorithm that showed the effects of different pollution levels and global warming on the porosity of Portland cement in a time window of years. Finally, a theoretical study on the effects of pollution levels on the carbonation constant determining the advancement in the carbonation front was carried out for the analyzed scenarios.

Effect of Pollution Level on Size Distributions and Mixing State of Ambient Black Carbon Particles in an Urban Area during Wintertime

We deployed a Single Particle Soot Photometer (SP2) and Single Particle Aerosol Mass Spectrometer (SPAMS) to investigate the size distribution and mixing state of ambient black carbon (BC) particles in Shanghai during the winter of 2017. The mixing state of the particles changed drastically under different meteorological conditions, and higher concentrations often occurred during haze episodes. The BC particles existed in two size modes: the condensation mode, which mainly consisted of fresh traffic-emitted particles, and the droplet mode, which encompassed heavily aged traffic-emitted particles, biomass burning particles and heavy-duty diesel engine emission particles. Whereas the heavily aged traffic-emitted particles exhibited relatively small BC cores (60–80 nm in diameter) surrounded by a thick coating (100–160 nm), the biomass burning particles displayed slightly larger cores (80–130 nm) covered by an even thicker layer (160–300 nm). However, we observed a large number of particles with large cores (150–200 nm) but a relatively thin coating (40–80 nm) on clean days. Trajectory analyses of the air masses showed that they usually originated in local areas or on the North China Plain during haze episodes but mostly migrated from the East China Sea during clean episodes. Interestingly, the BC particles in the clean air masses contained V more frequently and generated intense mass spectrum signals for Ca+, suggesting that these particles probably arose from heavy machinery emissions near ports. Our real-time single particle data indicates that the sources of BC aerosol can be easily identified by measuring the size distribution and mixing state of the particles.

Investigation of heavy metal uptake by three types of ornamental plants as affected by application of organic and chemical fertilizers in contaminated soils

Accumulation of heavy metals in soil media is considered as a serious environmental problem, which is hazardous to human and animal health. There have been several methods for the removal of these toxic metals. One of the commonly used methods is the use of plants, especially ornamental plants to remove heavy metals from soils. In this regard, the study has been conducted on the soils contaminated with Mn, Pb, Ni, and Cd using factorial experiment in a completely randomized design with two factors including three types of soil (soil A for the highest level of contamination, B for the lowest level of pollution, and C for the non-contaminated soil) with different contamination levels as well as three types of ornamental plants, gladiolus, daffodils, and narcissus with four replications. In another part of the study, soil A and gladiolus were used in a completely randomized design with three replications, and also three types of fertilizers, such as municipal solid waste compost, triple superphosphate and diammonium phosphate, were added to this soil. In addition, the availability of heavy metal was studied in gladiolus as influenced by the application of organic and chemical fertilizers. The results showed that heavy metal pollution caused reduction in the dry weight of gladiolus and tulips compared to the control sample, while there was no significant effect of pollution on the dry weight of narcissus. The uptake of Mn, Pb, Ni, and Cd by all three plants has been increased with enhancing the pollution levels of heavy metals. The highest concentration of Pb in the shoots of plants was observed in soil A with an average amount of 61.16 (mg kg−1), which revealed a substantial difference relative to the treatment of soil B and C. The most and least amount of Ni in the plants shoots were related to soil A and soil C with an average of 2.35 and 0.89 mg kg−1, respectively. The uptake of Pb by shoots of all three plants was nearly similar to each other, while more Pb was absorbed by the bulbs of gladiolus compared to the bulbs of other plants. Increment in the pollution levels led to the decrement in enrichment factor (EF); however, there was no effect of pollution levels on EF of Mn and Pb. Moreover, there was no effect of increasing pollution levels on translocation factor of these elements. In gladiolus, after application of organic and chemical fertilizers, it was observed that the concentration of heavy metals was far more in the bulbs compared to the shoots. In conclusion, the cultivation of these ornamental plants is highly recommended due to not only their decorative aspect but also their ability for bioremediation as well as being economical.

Fine particulate air pollution and hospitalization for pneumonia: a case-crossover study in Shijiazhuang, China

Many epidemiological studies have shown that airborne particulate matter (PM) is a risk factor for multiple respiratory diseases and increased hospitalization rates. Fine PM (PM2.5, diameter <2.5 μm) is considered to be a greater health hazard than coarse PM (PM10, 2.5–10 μm) because it adsorbs more harmful substances and can enter deeper parts of the lungs. We investigated the correlation between hospitalization for pneumonia and PM2.5 levels in Shijiazhuang, a city in northern China. Daily data on hospitalizations for community-acquired pneumonia and ambient air pollution levels in Shijiazhuang were obtained for 2013. A bidirectional case-crossover design was used to investigate the association between hospitalization for pneumonia and atmospheric PM2.5, PM10, SO2, NO2, CO, and O3 levels. The effects of pollutant levels from lag0 (day of hospitalization) to lag5 (five days before lag0) were investigated in both single and multi-pollutant models, adjusted for daily weather variables. For the single-pollutant model, hospitalization for pneumonia correlated positively with higher PM2.5 levels, with an increase of 1.1 % in daily admissions per 10-μg/m3 increase in the PM2.5 level at lag0. In the multi-pollutant model, the observed effects of PM2.5 remained significant. Stratified analysis of exposure based on sex, age, season, and comorbidities showed that the effect of PM2.5 on hospitalization for pneumonia was stronger in males, people younger than 60 years, people without comorbidities, and on warm days. These results indicate that higher levels of PM2.5 increase the risk of hospitalization for pneumonia in Shijiazhuang, China.

Comparison of transient associations of air pollution and AMI hospitalisation in two cities of Alberta, Canada, using a case-crossover design

ObjectiveTo investigate reproducibility of outcomes for short-term associations between ambient air pollutants and acute myocardial infarction (AMI) hospitalisation in 2 urban populations.DesignUsing a time-stratified design, we conducted independent case-crossover studies...

RETRACTED: Temperature control of a cabin in an automobile using thermal modeling and fuzzy controller

abstract This paper covers thermal modeling of a cabin in an automobile to find and control the air temperature bythe means of fuzzy controller. Therefore, in first step, the thermal and ventilation loads were estimatedthen the equations of dry air mass and energy conservation as well as internal components of a cabinwere derived and solved simultaneously. The performance of the proposed thermal modeling of a cabinwas compared with the experimental hot room test. In the next step, to maintain thethermal comfort of acabin and controlling the two effective parameters (blower outgoing air velocity and the circulated airpercentage), a fuzzy controller was applied. Results showed that when using a fuzzy controller, the tem-perature control of a cabin took shorter time period and as a result, the time spent for ventilating andcooling the cabin as well as the fuel consumption are reduced. 2012 Elsevier Ltd. All rights reserved. 1. IntroductionControlling thermal comfort of passengers in a cabin is impor-tant. The temperature and thermal comfort control of a cabin foran automobile would be possible by using proper controller. Mat-sui et al. [1] used modern control theory for thermal analyses of anautomobile cabin and determined the governing equations of themodel by means of statistical methods. Lim et al. [2] employed amicrocontroller which continually recorded the temperature of acabin and sent the controlling commands to the compressor in or-der to maintain the cabins thermal comfort for passengers. Daviset al. [3] used a fuzzy controllingsystem due to nonlinearand com-plex nature of governing equations in thermal modeling of a cabin.Wei and Dage [4] designed the control system of a cabin for anautomobile based on intelligent methods. Durovic and KovaZeviC[5] used artificial neural network under several weather conditionsto control the temperature of a cabin. Aeatrice et al. [6] analyzedthe dynamic mode of a refrigeration cycle to analyze the thermalcomfort of a cabin and to control the air conditioning system instate space. In his work, the moisture produced by passengerswas measured by a sensor, while the governing equations werejust applicable to 100% circulated return air passing over the evap-orator. Qi and Deng [7] introduced a fuzzy controller for modelingthe thermal comfort inside the cabin of a car in which only theinlet air volume rate was considered for air temperature control.Farzaneh and Tootoonchi [8] used a fuzzy controller with temper-ature feedback to supervise the thermal comfort of a cabin.In the first part of this paper the thermal and ventilation loadswere estimated, and then the mass and energy balance equationsfor dry air as well as the balance equations for internalcomponentsof a cabin were derived and solved simultaneously. The proposedcabin thermal model was validated by hot room test experimentaldata. Then a fuzzy controller was applied to the model to controlthe cabin’s temperature. The velocity of air passing through theblower and the position of the circulating air vent were controlledby this type of cabins air condition controller. The modeling wouldhelp designers to adapt the air conditioning system of an automo-bile with the design of an internal temperature controlling system.The followingare the contributionof this paperinto the subject:1. Effect of pollution level in an outside weather.2. Control the air circulation ratio with a fuzzy controller.2. Thermal modeling and governing equations for a cabinThe cabin thermal modeling was performed by using theLumped Capacitance Method in which the temperature distribu-tion was assumed to be spatially uniform. The variation of temper-ature and relative humidity of the air inside the cabin wasestimated using dynamic equations of operating conditions whichwere influenced by: solar radiation load received by outer surfacesand windows of an automobile, convection and conduction heattransfer loads of a cabin, effect of sensible and latent heat as well