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The Influence of Different Pavement Surfaces on Atmospheric Copper, Lead, Zinc, and Suspended Solids Attenuation and Wash-Off Full text
2015
Murphy, Louise U. | Cochrane, Thomas A. | O’Sullivan, Aisling
From a storm water management perspective, not all pavements are equivalent. Pavement type can impose a strong influence on pollutant wash-off dynamics. Pollutant loads from pavement wash-off are affected by the pavements’ physical and chemical composition. However, there is a dearth of information regarding how pavement type influences atmospherically deposited pollutant loads in storm water. Therefore, experimental impermeable and permeable asphalt and concrete boards were deployed in a residential area in Christchurch, New Zealand, to quantify the influence of pavement type on storm water pollutant dynamics. Each pavement type had four replicate systems elevated 500 mm from the ground at a 4° slope. Wash-off from the pavements was collected and analysed for total suspended solids and metals (Cu, Pb, and Zn) from June to August 2014. Results show that Cu and Zn loads were lower from the concrete pavements than the asphalt pavements because the carbonates and hydroxides within the concrete adsorbed Cu and Zn. Run-off from the impermeable asphalt had the highest loads of Zn, which was attributed to Zn leaching from the asphalt. Infiltrate from permeable asphalt provided little/no retention of Cu and Zn, due to the low pH of the infiltrate causing Cu and Zn to partition into the dissolved phase and leach through the pavement. Total suspended solid (TSS) and Pb loads were the highest in run-off from the impermeable concrete, which was attributed to the smooth surface enabling particulates to be easily mobilised. TSS and Pb loads were the lowest from the permeable pavement due to the permeable material filtering out particulates.
Show more [+] Less [-]Superporous Cryogel-M (Cu, Ni, and Co) Composites in Catalytic Reduction of Toxic Phenolic Compounds and Dyes from Wastewaters Full text
2015
Sahiner, Nurettin | Seven, Fahriye | Al-lohedan, Hamad
P(Acrylamide) (p(AAm)) cryogel with superporous structure was synthesized by employing a cryopolymerization technique under freezing conditions. The prepared cryogels were modified by amidoximation to generate new functional groups as amid-p(AAm) cryogel, that binds metal ions, and the metal nanoparticles of those ions were prepared via in situ reduction method. The prepared amid-p(AAm)-M cryogel composites (M: Cu, Ni, and Co) were used as superporous reactor for the catalytic reduction of toxic phenol compounds 2- and 4-nitrophenol (2- and 4-NP) and some dyes methylene blue (MB) and Eosin Y (EY). P(AAm) cryogels and their metal composites were characterized by using FT-IR analysis, SEM images, and AAS measurements. The impact of porosity, the types and amount of metal catalyst, temperature of reaction medium, and so on were investigated for toxic 2-NP reduction by amid-p(AAm)-M cryogel composites. Very high total turnover frequencies (TOF) and low activation energy (Ea) values of 2.46 (mole 2-NP) (mole Cu. min)⁻¹and 20.2 kJmol⁻¹were obtained for catalytic reduction of 2-NP compound catalyzed by amid-p(AAm)-Cu cryogel composites. Consequently, superporous p(AAm) cryogel is the perfect support material for metal nanoparticle preparation and use in catalytic reduction reactions.
Show more [+] Less [-]Optimization, Kinetics, Isotherms, and Thermodynamics Studies of Antimony Removal in Electrocoagulation Process Full text
2015
Song, Peipei | Yang, Zhaohui | Zeng, Guangming | Yang, Xia | Xu, Haiyin | Huang, Jing | Wang, Like
In this study, electrocoagulation (EC) with hybrid Fe–Al electrodes was used to remove antimony from contaminated surface water. Response surface methodology was applied to investigate the interactive effects of the operating parameters on antimony removal and optimize these variables. Results showed that the relationship between operating parameters and the response was well described by a second-order polynomial equation. Under the optimal conditions of current density 2.58 mA/cm², pH 5.24, initial concentration 521.3 μg/L, and time 89.17 min, more than 99 % antimony were removed. Besides, the antimony adsorption behavior in EC process was also investigated. Adsorption kinetics and isotherms studies suggested that the adsorption process followed well the pseudo-second-order kinetic model and the Langmuir adsorption model, respectively. Adsorption thermodynamics study revealed that the reaction was spontaneous, endothermic, and thermodynamically favorable. These results further proved that the main mechanism involved in antimony removal in EC process could be chemisorption.
Show more [+] Less [-]Heavy Metal Uptake by Herbs. IV. Influence of Soil pH on the Content of Heavy Metals in Valeriana officinalis L Full text
2015
Adamczyk-Szabela, Dorota | Markiewicz, Justyna | Wolf, Wojciech M.
The aim of the study was to estimate the influence of soil pH on the uptake of copper, zinc, and manganese by Valeriana officinalis. Preliminary studies involved soil analyses to determine acidity, organic matter content, and copper, zinc, and manganese total and bioavailable forms. The study involved atomic absorption spectrometry to determine the concentration of the elements, and mineral soil of pH = 5.1 was used in the study, as being typical for central Poland. The copper, zinc, and manganese contents were determined in plants grown in soils which had been modified to cover a wide range of pH values 3÷13. The intensity of germination was strongly pH dependent with the highest yield obtained in original, unmodified soil. Surprisingly, high soil alkalinity stimulated copper and manganese uptake while at the same time resulting in a decrease in zinc content.
Show more [+] Less [-]Geostatistical Microscale Study of Magnetic Susceptibility in Soil Profile and Magnetic Indicators of Potential Soil Pollution Full text
2015
Zawadzki, Jarosław | Fabijańczyk, Piotr | Magiera, Tadeusz | Rachwał, Marzena
Directional variograms, along the soil profile, can be useful and precise tool that can be used to increase the precision of the assessment of soil pollution. The detail analysis of spatial variability in the soil profile can be also an important part of the standardization of soil magnetometry as a screening method for an assessment of soil pollution related to the dust deposition. The goal of this study was to investigate the correlation between basic parameters of spatial correlations of magnetic susceptibility in the soil profile, such as a range of correlation and a sill, and selected magnetometric indicators of soil pollution. Magnetic indicators were an area under the curve of magnetic susceptibility versus a depth in the soil profile, values of magnetic susceptibility at depths ranging from 1 to 10 cm, and maximum and background values of magnetic susceptibility in the soil profile. These indicators were previously analyzed in the literature.The results showed that a range of correlation of magnetic susceptibility was significantly correlated with magnetic susceptibility measured at depths 1, 2, and 3 cm. It suggests that a range of correlation is a good measure of pollutants’ dispersion in the soil profile. The sill of the variogram of magnetic susceptibility was found to be significantly correlated with the area under the curve of plot of magnetic susceptibility that is related to the soil pollution. In consequence, the parameters of microscale spatial variability of magnetic susceptibility in s soil profile are important measures that take into consideration the spatial aspect of s soil pollution.
Show more [+] Less [-]Odour Samples Degradation During Detention in Tedlar® Bags Full text
2015
Szyłak-Szydłowski, Mirosław
In indirect olfactometry analysis, to avoid condensation or adsorption processes during or storage of the sample, containers made of suitable materials should be used. Also, reaction between the chemicals during transport from the source of the odour to the research laboratory is an important process which can influence on examinations’ results. Study included determination of the odour and compound concentrations of six gas mixtures. Gas samples were collected by silicone hoses into Tedlar® bags and tested by Nasal Ranger, SM-100 olfactometers and Photovac Voyager gas chromatograph. Time of keeping gas in bags was 78 h, and concentration of compounds was measured every hour, eight times per day. For benzene, acetone, 1,1-dichloroethylene, c-1,2-dichloroethylene, t-1,2-dichloroethylene, methyl ethyl ketone and vinyl chloride, 100 % decrease of concentration has been noticed within 78 h of holding in the bag. Average rate of loss of most compounds concentration was from 0.01 to 2.50 % for the first 30 h and from 0.35 to 18.50 % during the last 48 h of examination. Decreasing of odour concentration measured by Nasal Ranger (NR) in all series was between 0.00 and 4.98 % till 30 h, between 1.91 and 100 % in the last 48 h of test and between 1.61 and 100 % in 78 h. In case of odour concentration measured by SM, those values were, respectively, 1.26–4.93 %, 1.39–4.93 % and 2.40–3.18 %. Values of average rate of intensity decreasing were, respectively, 0.77–1.75 %, 2.36–4.67 % and 1.18–2.07 %. Statistically significant correlation coefficients for compound concentrations and intensity, odour concentration obtained by SM-100 as well as NR were, respectively, 0.55–0.97, 0.47–0.99 and 0.37–0.98.
Show more [+] Less [-]Optimization and Comparison of Cd Removal from Aqueous Solutions Using Activated and Non-activated Carbonaceous Adsorbents Prepared by Pyrolysis of Oily Sludge Full text
2015
Mohammadi, Shohreh | Mirghaffari, Nourollah
New porous carbonaceous adsorbents were prepared from an oily sludge generated in a fuel oil storage tank using pyrolysis with and without activation by KOH at 600 °C. The pore characteristics of the activated carbonaceous adsorbent (AC), due to the formation of micropores and mesopores structure, were considerably better than those of non-activated carbonaceous adsorbent (NA). The adsorption of Cd from aqueous solutions on the produced carbonaceous adsorbents was optimized using the Taguchi method. Under optimum conditions, the Cd adsorption efficiency for the NA and AC was obtained to be 77.7 and 98.2 %, respectively. The initial concentration and the adsorbent dose were the most significant factors affecting the removal of Cd by NA and AC, respectively. The adsorption data for the AC were well fitted by the Langmuir, Freundlich, and Redlich-Peterson isotherms models. The regeneration and reuse of the adsorbents in the three cycles of Cd adsorption-desorption were possible. The carbonaceous adsorbents had acceptable efficiency for the removal of Cd from a mine wastewater. Based on the obtained results, the oily sludges available in huge amounts in the petroleum industry proved to be a potential precursor resource for the production of the porous carbonaceous adsorbents, particularly for application in the wastewater treatment.
Show more [+] Less [-]Optical Fiber Technology for Monitoring and Preventing Biomass Washout from Bioreactors: a Case Study with a Sequencing Batch Reactor (SBR) Full text
2015
Silva, Flávio C. | Martins, Martinho A. S. | Bilro, Lúcia | Nogueira, Rogério N. | Capela, Isabel | Keizer, J Jacob
Optical Fiber Technology for Monitoring and Preventing Biomass Washout from Bioreactors: a Case Study with a Sequencing Batch Reactor (SBR) Full text
2015
Silva, Flávio C. | Martins, Martinho A. S. | Bilro, Lúcia | Nogueira, Rogério N. | Capela, Isabel | Keizer, J Jacob
A novel plastic optical fiber (POF) sensor was investigated to monitor total suspended solids (TSS) concentration continuously, offering insights into wastewater treatment bioreactors without disturbing them. First, off-line experiments with both anaerobic and aerobic sludge (in concentrations ranging between 0.1 and 8.6 g TSS L⁻¹) were used to establish the exponential relationship of the sensor’s transmitted optical power with TSS concentrations. Attenuation coefficients differed clearly with the type of sludge (1.227–1.274 and 0.456–0.679 for anaerobic and aerobic biomass, respectively) and, in the case of the aerobic sludge, with its coloring. The POF sensor was further used for online monitoring of sludge settling profiles inside a sequencing batch reactor (SBR) that was being operated under a “feast-famine” regime. The turbidity profiles agreed very well with the Boltzmann equation. The Boltzmann dx parameter revealed clear differences in the steepness of the settling gradients, which could be explained by the changes in the applied organic loading rates (OLR). OLR in the range of 1.34–1.53 g COD L⁻¹ day⁻¹ resulted in steeper settling gradients than OLR in the range of 2.13–3.12 g COD L⁻¹ day⁻¹ (dx: 0.42–0.50 vs. 0.90–1.36). Thus, the POF sensor not only revealed elevated potential for prediction of biomass concentration but also for becoming an integral part of real-time automation systems in order to diminish repeated sampling and off-line analysis to control the withdrawal phase based on seasonal sludge settling profiles.
Show more [+] Less [-]Optical fiber technology for monitoring and preventing biomass washout from bioreactors: a case study with a sequencing batch reactor (SBR) Full text
1000 | 2015
Silva, Flávio C. | Martins, Martinho A. S. | Bilro, Lúcia | Nogueira, Rogério N. | Capela, Isabel | Jacob Keizer, J.
A novel plastic optical fiber (POF) sensor was investigated to monitor total suspended solids (TSS) concentration continuously, offering insights into wastewater treatment bioreactors without disturbing them. First, off-line experiments with both anaerobic and aerobic sludge (in concentrations ranging between 0.1 and 8.6 g TSS L−1) were used to establish the exponential relationship of the sensor’s transmitted optical power with TSS concentrations. Attenuation coefficients differed clearly with the type of sludge (1.227– 1.274 and 0.456–0.679 for anaerobic and aerobic biomass, respectively) and, in the case of the aerobic sludge, with its coloring. The POF sensor was further used for online monitoring of sludge settling profiles inside a sequencing batch reactor (SBR) that was being operated under a Bfeast-famine^ regime. The turbidity profiles agreed very well with the Boltzmann equation. The Boltzmann dx parameter revealed clear differences in the steepness of the settling gradients, which could be explained by the changes in the applied organic loading rates (OLR). OLR in the range of 1.34–1.53 g COD L−1 day−1 resulted in steeper settling gradients than OLR in the range of 2.13–3.12 g COD L−1 day−1 (dx: 0.42–0.50 vs. 0.90–1.36). Thus, the POF sensor not only revealed elevated potential for prediction of biomass concentration but also for becoming an integral part of real-time automation systems in order to diminish repeated sampling and off-line analysis to control the withdrawal phase based on seasonal sludge settling profiles.
Show more [+] Less [-]Contribution of Coagulation–Flocculation Process for a More Sustainable Pig Slurry Management Full text
2015
Fragoso, R. A. | Duarte, E. A. | Paiva, J.
This paper aims to demonstrate the benefits of using a natural coagulant to enhance gravitational sedimentation of pig slurry. The separation process would lead to a liquid fraction, more biodegradable and with lower nutrient content, and a solid fraction highly concentrated in organic matter. Experimental trials were conducted in order to achieve the following objectives: (i) compare the effect of gravitational sedimentation with coagulation–flocculation process, (ii) compare the efficiency of conventional coagulants (such as aluminium sulphate or ferric chloride) with chitosan biopolymer and (iii) test the optimum coagulation–flocculation operational conditions to slurry sample. Assessment criteria included removal efficiencies but also took into consideration the advantages/disadvantages regarding sludge management. Results showed that gravitational sedimentation process can be improved by addition of coagulants; turbidity and COD removal increased around 2 and 3 times, respectively.
Show more [+] Less [-]Formaldehyde Removal from Airstreams Using a Biofilter with a Mixture of Compost and Woodchips Medium Full text
2015
Rezaei, Mohsen | Fazlzadehdavil, Mehdi | Hajizadeh, Yaghoub
The performance of a laboratory-scale biofilter packed with a mixture of compost and woodchip on formaldehyde removal from polluted air streams was investigated. The reactor was inoculated with aerobic sludge as a source of bacteria, obtained from a municipal wastewater treatment plant. A nutrient solution was daily added to the reactor media. An airflow containing different concentrations of formaldehyde (from 20 ± 2 to 276 ± 5 mg m⁻³) was introduced into the reactor. In inlet formaldehyde concentration, an average removal efficiency and elimination capacity of 91 % and 0.36 g m⁻³ h⁻¹were attained, respectively, at180 s empty bed residence time (EBRT). After acclimatization of the system for increased formaldehyde concentrations of up to 276 ± 5 mg m⁻³and for EBRT of 180 s, those values were stabilized at around 72 % and 3.98g⁻³ h⁻¹, respectively. The experimental results showed that the system was effective for a high loading rate of formaldehyde with an acceptable EBRT. Compared to the application of compost alone as a media, a mixture of compost and woodchip (50/50 v/v%) enhanced the performance of the biofilter. The most predominant microorganism involved in the biodegradation of formaldehyde was a species of citrobacter called Citrobacter freundii, an aerobic gram-negative bacillus. Pressure drop of the reactor over the entire operations was about 1 mmH₂O m⁻¹.
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