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Effect of Residual NAPLs on the Transport of Bisphenol A and Bisphenol S in Saturated Porous Media
2019
Shi, Yanfeng | Gao, Bin | Sun, Yuanyuan | Sun, Kaixuan | Xu, Hongxia | Wu, Jichun
Endocrine disrupter, like bisphenol A (BPA) and bisphenol S (BPS), is frequently detected in the subsurface environment, imposing threats to the groundwater quality and public health. However, current understanding of environmental fate and transport of BPA/BPS is still not clear, especially with respect to those in the subsurface media with trapped non-aqueous phase liquids (NAPLs). In this study, the effect of residual NAPLs on the retention and transport of BPA/BPS in the saturated sand and soil media was investigated using column experiments. The results showed that residual NAPLs (i.e., xylene and perchloroethylene (PCE)) inhibited the transport of BPA in the sand columns, and the inhibit effect of xylene was greater than that of PCE. While the presence of NAPLs showed little influence on the transport of BPS in the sand columns, in soil A (sandy soil), the residual NAPLs had similar effect on the retention and transport of BPA and BPS. Both BPA and BPS showed higher retention in the soil B columns than in the sand and soil A columns due to soil B’s higher organic matter contents, which can strongly sorb BPA/BPS. The presence of residual NAPLs reduced the retention of BPA/BPS in the soil B columns because the NAPLs blocked the sorption sites of the soil organic matter for BPA/BPS. This study demonstrates the importance of residual NAPLs, types of media, properties of contaminants, and their interactions to the fate and transport of BPA/BPS in saturated porous media.
Show more [+] Less [-]Correction to: Adsorption, Kinetics and Equilibrium Studies on Removal of Catechol and Resorcinol from Aqueous Solution Using Low-Cost Activated Carbon Prepared from Sunflower (Helianthus annuus) Seed Hull Residues
2019
Vunain, Ephraim | Houndedjihou, Dégninou | Monjerezi, Maurice | Muleja, Adolph Anga | Kodom, BarthélémyTomkouani
In the original publication, the given name of the fourth author was mispelled as Adolp instead of Adolph. The correct name of the fourth author is Adolph Anga Muleja.
Show more [+] Less [-]Effect of Copper Oxide Nanoparticles on the Physiology, Bioactive Molecules, and Transcriptional Changes in Brassica rapa ssp. rapa Seedlings
2019
Chung, Ill-Min | Rekha, Kaliyaperumal | Venkidasamy, Baskar | Thiruvengadam, Muthu
Global deterioration of water, air, and soil quality by the release of toxic chemicals from anthropogenic pollutants is becoming a serious global problem. The extensive use of copper oxide nanoparticles (CuO NPs) can be environmentally hazardous when these NPs enter the atmosphere. The present study aimed to evaluate the role of CuO NPs on plant growth, photosynthetic capacity, and bioactive compounds, as well as their transcriptional level changes in Brassica rapa seedlings. Chlorophyll, carotenoid, and sugar content decreased, while proline and anthocyanins were significantly enhanced in the CuO NP-treated seedlings compared with the untreated controls. Reactive oxygen species (ROS), malondialdehyde (MDA), and hydrogen peroxide (H₂O₂) production were also enhanced in the seedlings exposed to CuO NPs, which could have caused DNA damage that was detected by a DNA laddering assay. The glucosinolate (GSL) and phenolic compound content were significantly increased in CuO NP-treated seedlings compared with that in control seedlings. Transcriptional variation of genes associated with oxidative stress (CAT, POD, and GST), R2R3-type MYB involved in GSL (BrMYB28, BrMYB29, BrMYB34, and BrMYB51), and phenolic compounds (ANS, PAP1, PAL, and FLS) biosynthesis was analyzed using real-time polymerase chain reaction. Significant upregulation of CAT, POD, GST, BrMYB28, BrMYB29, BrMYB34, BrMYB51, ANS, PAP1, PAL, and FLS genes was observed in seedlings exposed to different concentrations of CuO NPs relative to the untreated seedlings. Therefore, we suggest that the use of CuO NPs could stimulate the toxic effects and enhance phytochemicals (i.e., glucosinolates and phenolic compounds) in B. rapa.
Show more [+] Less [-]Effect of Salinity on the Adsorption Behavior of Methylene Blue onto Comminuted Raw Avocado Residue: CCD-RSM Design
2019
Schadeck Netto, Matias | da Silva, Nathalia Favarin | Mallmann, Evandro Stoffels | Dotto, Guilherme Luiz | Foletto, Edson Luiz
Textile effluents contain a series of dyes and salts, and their decolorization is strongly affected by salinity. In this work, the influence of salinity on methylene blue (MB) adsorption by comminuted raw avocado seeds was investigated. The adsorbent was firstly characterized. The optimal conditions for MB adsorption on the avocado seeds were determined by response surface methodology (RSM). Subsequently, the influence of ten salts in MB adsorption was evaluated using kinetic and equilibrium studies. The optimal conditions for MB adsorption on the avocado seeds were pH = 10 and adsorbent dosage = 1 g L⁻¹. General order model was able to describe the kinetic profile, and its parameters showed that the adsorption rate and capacity were affected by the presence of salts. The equilibrium was adequately represented by the Sips model. The maximum adsorption capacity without the presence of salts was 97.97 mg g⁻¹. The maximum adsorption capacity was found in the presence of sodium carbonate, which was 103.13 mg g⁻¹. The presence of sodium citrate reduced the adsorption capacity to 80.42 mg g⁻¹. Therefore, even in the presence of salts, comminuted raw avocado seeds demonstrated great potential to treat colored effluents containing MB dye.
Show more [+] Less [-]The characterization and methane adsorption of Ag-, Cu-, Fe-, and H-exchanged chabazite-rich tuff from Turkey
2019
Sakızcı, Meryem | Özer, Mehmet
In this study, a chabazite-rich tuff (CHA) from the Bala deposit of Ankara region (Turkey) and its modified forms (CuCHA, AgCHA, FeCHA, and HCHA samples) were investigated at 273 and 298 K using volumetric apparatus up to 100 kPa. The chabazite samples were characterized by using thermal analysis (TG-DTG-DTA), X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy with detector X-ray energy dispersive (SEM-EDX), Fourier transform infrared (FT-IR), and N₂ adsorption methods. It was found that natural chabazite is composed of predominantly chabazite with small amounts of clinoptilolite and erionite. XRD showed that there are major structural changes to Fe- and H-exchanged chabazite samples. Capacity of chabazites for CH₄ ranged from 0.168 and 1.341 mmol/g. Among all the modified forms, it was observed that Ag form of chabazite zeolite had the greatest methane adsorption capacity at both temperatures.
Show more [+] Less [-]Windbreak Wall-vegetative Strip System to Reduce Air Emissions from Mechanically-Ventilated Livestock Barns – Part 1: CFD Modeling
2019
ʻAjamī, ʻAlī | Shah, Sanjay B. | Stikeleather, Larry F.
The adverse effects of air emissions from animal feeding operations (AFOs) on public health, environment, and quality-of-life have been well-documented. Regulations or lawsuits may force AFOs to reduce their air emissions. Since livestock barn particulate matter (PM) has relatively high particle density and diameter and many gasses adsorb onto PM, its filtration might reduce air emissions. A porous windbreak wall that imposes acceptable backpressure (< 12.5 Pa) and covers the fan could be a promising option. Seventy-two different porous windbreak wall scenarios were modeled to compare their backpressure on the fan as well as average airspeed over the ground. These scenarios were combinations of shape (box, chamfered, curved), size (lengths of 2, 2.5, and 3 fan diameters), presence or absence of an opening (opened and closed), screen porosity (mosquito screen or clean screen, SunBlocker 70% or clogged screen), and fan angle and height. Backpressure and airspeed decreased with increasing windbreak wall length. Generally, the box-shaped windbreak wall had lower backpressure and airspeeds than the other shapes. The increased backpressure with clogged screen even at two fan diameters (2d) was acceptable. The tilted fan commonly used in poultry houses had higher backpressure and airspeed over the ground than the non-tilted fan used in swine houses due to the former’s lower surface area and tilt towards the ground. Overall, taking into account cost considerations and footprint size (for retrofittability), despite its higher airspeed over the ground (vs. larger footprints) and modest reduction in airflow rate, the 2d, open box model seems the most promising option.
Show more [+] Less [-]UV-Light Catalyzed Reduction of Cr(VI) by Graphene Oxide and its Significance for Cr(VI) Transformation in an Oxisol
2019
Zhang, Yali | Yang, Jiewen
Due to its unique properties, the potential application of graphene oxide (GO) in treating environmental pollution has attracted wide attention. In this study, the UV-light catalyzed photoreduction of Cr(VI) by GO was assessed as well as its adsorption toward Cr(VI), and FTIR and XPS techniques were adopted to reveal the underlying mechanisms. The surfaces of GO were negatively charged across the pH range examined. Therefore, the increase in pH resulted in the decrease in Cr(VI) adsorption due to the enhancement in repulsion between Cr(VI) and GO surfaces. The kinetic studies showed that the Cr(VI) adsorption proceeded quickly during the 0–24 h stage, followed by a slow process until to the end of reaction (96 h). Additionally, the kinetic data could be properly described with the pseudo-first-order rate equation (R² = 0.9754). With the UV-light irradiation, Cr(VI) reduction in the presence of 0.5 g L⁻¹ GO was observed with the concentration of Cr(VI) decreased from 0.1 mM to zero within 12 h at pH 3.0, while which would be suppressed as the pH increased. The addition of EDTA could enhance the photocatalytic Cr(VI) reduction due to the consumption of the photogenerated holes (h⁺), leaving more Cr(III) species present in solution. The generation of h⁺ was further confirmed by the complete photodegradation of 4-CP during 48 h. Moreover, the changes in FTIR and XPS spectrum of GO before and after reaction indicated the oxidization of epoxy and hydroxyl groups by holes or reduction by electrons was involved in the photoreaction. The photoreduction of Cr(VI) could was also observed in an oxisol with the existence of GO, with the disappearance of 0.1 mM of aqueous Cr(VI) at pH 4.40 after 36 h. The results above could enhance our understanding on the essence of photoreactivity of GO, and indicated that the potential release of GO into soil environments would be helpful to eliminate the risk posed by Cr(VI) through the UV-light irradiated photocatalytic reduction.
Show more [+] Less [-]Body size variation of the ant Lasius niger along a metal pollution gradient
2019
Grześ, Irena M. | Okrutniak, Mateusz | Gorzałczany, Monika | Piszczek, Piotr
The phenotypic diversity of ant workers plays a fundamental role in their biology. In this study, we asked if the body size variation of monomorphic workers of the ant Lasius niger (Formicidae) responds adaptively to metal pollution in a post-mining metal-polluted area. Nest samples of workers were collected along a pollution gradient to calculate the within-colony variance in body size (expressed as maximum head width, HW). The results showed that the body size variation of L. niger was unrelated to the pollution index but demonstrated considerable variation between colonies even within the same study site. We suggest that the differences in morphological diversity between the colonies of L. niger could be shaped by colony personality traits, i.e., by colony-specific foraging and/or the feeding efficiency of nursing workers. The study supports previous findings, showing that morphological traits in Lasius ants are weakly related to environmental metal pollution.
Show more [+] Less [-]Impact of chlorpyrifos on behavior and histopathological indices in different tissues of freshwater fish Channa punctatus (Bloch)
2019
Stalin, Arumugam | Suganthi, Palani | Mathivani, Subramanian | Paray, Bilal Ahmad | Al-Sadoon, Mohammad K. | Gokula, Varadharajan | Musthafa, Mohamed Saiyad
The present systematic experiment was conducted to estimate the impact of behavioral and pathological indices on freshwater fish Channa punctatus exposed to sub-lethal concentration (5 ppm) of an organophosphorus insecticide chlorpyrifos (CPF). Fish were segregated into four experimental groups (G1, control; G2, 10 days; G3, 20 days; and G4, 30 days exposure), each group comprises 15 fish in triplicate. The behavioral and histological changes were assessed in each group. Severe behavioral changes were observed in the 30 days, moderate changes in the 20 days, and mild changes in the 10 days exposure groups respectively when compared with the control group. The pathologic lesions such as inter lamellae space, necrotic lamellae, fused lamellae, and lifting of lamellae epithelium in gills; vacuolation, blood conjunctions, and necrotic hepatocytes in the liver; and lamina propria, fusion of villi, and flattened villi in the intestine were observed. These structural alterations of the gills, liver, and intestine could affect respiration, osmotic and ionic regulation; absorption, storage and secretion; digestion; and absorption of nutrients respectively, which in turn could adversely affect the growth and survival of freshwater fish Channa punctatus. This study serves as a biomonitoring tool for the effects of organophosphorus insecticide CPF on the aquatic biota.
Show more [+] Less [-]Global trends and future prospects of e-waste research: a bibliometric analysis
2019
Gao, Ya | Ge, Long | Shi, Shuzhen | Sun, Yue | Liu, Ming | Wang, Bo | Shang, Yi | Wu, Jiarui | Tian, Jinhui
Electronic waste (e-waste) has been widely studied by scholars all over the world, but the research topics and development trends in this field are still unclear. This study aimed to explore the status quo, hot topics, and future prospects in the field of e-waste. Data of publications were downloaded from the Web of Science Core Collection. We used CiteSpace V, Histcite, and VOSviewer to analyze literature information. A total of 2800 papers in e-waste research were identified, and the number of publications increased rapidly after 2004. Six thousand five hundred seventy-three authors participated in the e-waste research, but 70.01% of the authors published only 1 article. The most productive country in this field was China (1146 publications), and the most productive institution was the Chinese Academy of Sciences (370 publications). The Waste Management (225 publications) was the most productive journal, and Environment Science & Technology (9704 co-citations) was the most co-cited journal. The main hot topics in e-waste field were management and recycling of e-waste in developing countries, health risk assessment after exposure to organic pollutants, degradation and recovery of waste metal materials, and impact of heavy metals on children’s health. The frontier topic was degradation.
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