Refine search
Results 3431-3440 of 4,308
Phosphate-arsenate relations to affect arsenic concentration in plant tissues, growth, and antioxidant efficiency of sunflower (Helianthus annuus L.) under arsenic stress Full text
2017
Azeem, Waqas | Ashraf, Muhammad | Shahzad, Sher Muhammad | Imatiāza, Muhammada | Akhtar, Mumtaz | Rizwan, Muhammad Shahid
Relations between phosphate and arsenate are important but inconsistent to influence arsenic (As) phytotoxicity depending on many plant and soil factors. Present research aimed to investigate the phosphate and arsenate interactions in sunflower (Helianthus annuus L.) grown in alkaline calcareous soil for 18 weeks under natural environmental conditions at three arsenate [0 (As₀), 40 (As₄₀), and 80 (As₈₀) mg As kg⁻¹ soil as sodium arsenate] and three phosphate [0 (P₀), 100 (P₁₀₀), and 200 (P₂₀₀) mg P₂O₅ kg⁻¹ soil as diammonium phosphate] levels. The plants were grown in pots according to completely randomized design with five replications. Ionic and physiological parameters were measured at 40 days after treatment completion. Arsenic contamination with As₄₀ and As₈₀ increased root and shoot As concentration with relatively higher concentration in roots, malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) while decreased plant P, chlorophyll, protein, and glutathione (GSH), and consequently plant growth, yield, and yield attributes. Addition of P₁₀₀ and P₂₀₀ under As stress reduced As transfer from soil to roots to shoots, MDA concentration, SOD, CAT, and POD activities while increased GSH, leaf protein, chlorophyll, and growth characteristics as well as achene yield compared to As-treated plants without additional P. In conclusion, P-induced inhibition of As transfer from soil to roots to shoots and reduction in MDA concentration accompanied with an increase in the synthesis of protein, chlorophyll, and GSH could be the main mechanisms responsible for lowered As toxicity in sunflower, leading to mitigation of potential risks of As contamination to food chain and human health.
Show more [+] Less [-]Leaching variations of heavy metals in chelator-assisted phytoextraction by Zea mays L. exposed to acid rainfall Full text
2017
Lu, Yayin | Luo, Dinggui | Liu, Lirong | Tan, Zicong | Lai, An | Liu, Guowei | Li, Junhui | Long, Jianyou | Huang, Xuexia | Chen, Yongheng
Chelant-enhanced phytoextraction method has been put forward as an effective soil remediation method, whereas the heavy metal leaching could not be ignored. In this study, a cropping-leaching experiment, using soil columns, was applied to study the metal leaching variations during assisted phytoextraction of Cd- and Pb-polluted soils, using seedlings of Zea mays, applying three different chelators (EDTA, EDDS, and rhamnolipid), and artificial rainfall (acid rainfall or normal rainfall). It showed that artificial rainfall, especially artificial acid rain, after chelator application led to the increase of heavy metals in the leaching solution. EDTA increased both Cd and Pb concentrations in the leaching solution, obviously, whereas EDDS and rhamnolipid increased Cd concentration but not Pb. The amount of Cd and Pb decreased as the leaching solution increased, the patterns as well matched LRMs (linear regression models), with R-square (R ²) higher than 90 and 82% for Cd and Pb, respectively. The maximum cumulative Cd and Pb in the leaching solutions were 18.44 and 16.68%, respectively, which was amended by EDTA and acid rainwater (pH 4.5), and followed by EDDS (pH 4.5), EDDS (pH 6.5), rhamnolipid (0.5 g kg⁻¹ soil, pH 4.5), and rhamnolipid (pH 6.5).
Show more [+] Less [-]Biochemical, hematological, and pathological related healing effects of Elaeagnus angustifolia hydroalcoholic extract in 5-fluorouracil-induced oral mucositis in male golden hamster Full text
2017
Koohi-Hosseinabadi, Omid | Ranjbar, Zahra | Sepehrimanesh, Masood | AndisheTadbir, Azadeh | Poorbaghi, Seyedeh Leila | Bahranifard, Hajar | Tanideh, Nader | Koohi-Hosseinabadi, Maryam | Iraji, Aida
Oral mucositis (OM) is one of the cancer chemotherapy-related side effects which can affect the quality of life of affected patients. This study was designed to investigate the healing effect of Elaeagnus angustifolia in 5-flurouracil (5-FU)-induced OM in golden hamster. Fifty-six adult male golden hamsters received three intraperitoneal injections of 5-FU at a dose of 60 mg/kg on days 0, 5, and 10. The cheek pouch mucosa was scratched superficially under local anesthesia. Then, two horizontal scratches were made across the everted cheek pouch on days 3 and 4. All treatments were started on day 12 for equal number of animals in control group with no treatments, gel base group that was treated with carboxy methyl cellulose as gel base which used in preparation of the topical gel, topical gel group that used gel containing 10% hydroalcoholic extract of E. angustifolia (HEEA) topically, and dietary group which was treated with 300 mg/kg HEEA. At 2 and 5 days after treatment, blood and pouch tissue sampling were done and analyzed for blood composition, tissue malondialdehyde (MDA) level, and myeloperoxidase (MPO) and superoxide dismutase (SOD) activities plus histopathological evaluations. Both topically and orally HEEA-treated groups showed a significant relief in OM compared to the control and base gel groups. However, the systemic form had higher efficiency in some parts especially decreasing the MPO (0.27 ± 0.17 vs. 0.56 ± 0.17 IU/L) and increasing SOD (6.46 ± 0.15 vs. 5.36 ± 0.18 IU/L) activities in pouch tissue in comparison to topical form mostly at 5 days after treatment. It seems that hydroalcoholic extract of E. angustifolia can be used as an appropriate drug choice for the treatment of oral mucositis based on its healing stimulatory and anti-inflammatory properties.
Show more [+] Less [-]Fe plaque-related aquatic uranium retention via rhizofiltration along a redox-state gradient in a natural Phragmites australis Trin ex Steud. wetland Full text
2017
Wang, Weiqing | Gert Dudel, E.
Studies have revealed that the rhizofiltration is a feasible plant-based technology for aquatic metal/metalloid removal. However, the performance of aquatic U retention via rhizofiltration has not been fully revealed yet. In this study, a field investigation was conducted in a Phragmites australis Trin ex Steud. dominated wetland to estimate the efficiency of Fe plaque (IP)-assisted U rhizofiltration, with redox-state gradient (−179 to 220 mV) and low aquatic U level (66.7 to 92.0 μg l⁻¹). The U concentrations were determined in soil, root, and aboveground biomass of P. australis. The IP on root surface was extracted via DCB extraction procedure. The bio-concentration factor (BCF) was applied to evaluate the aquatic U transfer capacity from root to above ground biomass of P. australis. The result suggested that root of P. australis was highly effective for aquatic U uptake via rhizofiltration (BCF 1025 to 1556). It also benefited the real U accumulation in aboveground biomass of P. australis (up to 0.4 mg m⁻²) and related plant-water-soil U recycling. The IP and associated microbial community in rhizosphere was effective mediator for aquatic U retention on root surface (BCF 1162 to 847). The IP-assisted aquatic U rhizofiltration was significantly promoted in relatively reductive environment. It was benefited by the enhanced root uptake of Fe due to lower oxidizers (e.g., DO and NO₃ ⁻) availability. On the other hand, the competitive adsorption effect from co-existing IP-affinitive elements (e.g., As) also possibly impaired the real capacity of IP-assisted aquatic U rhizofiltration via P. australis.
Show more [+] Less [-]Exploring the Legionella pneumophila positivity rate in hotel water samples from Antalya, Turkey Full text
2017
Sepin Özen, Nevgün | Tuğlu Ataman, Şenay | Emek, Mestan
The genus Legionella is a fastidious Gram-negative bacteria widely distributed in natural waters and man made water supply systems. Legionella pneumophila is the aetiological agent of approximately 90% of reported Legionellosis cases, and serogroup 1 is the most frequent cause of infections. Legionnaires’ disease is often associated with travel and continues to be a public health concern at present. The correct water management quality practices and rapid methods for analyzing Legionella species in environmental water is a key point for the prevention of Legionnaires’ disease outbreaks. This study aimed to evaluate the positivity rates and serotyping of Legionella species from water samples in the region of Antalya, Turkey, which is an important tourism center. During January−December 2010, a total of 1403 samples of water that were collected from various hotels (n = 56) located in Antalya were investigated for Legionella pneumophila. All samples were screened for L. pneumophila by culture method according to “ISO 11731-2” criteria. The culture positive Legionella strains were serologically identified by latex agglutination test. A total of 142 Legionella pneumophila isolates were recovered from 21 (37.5%) of 56 hotels. The total frequency of L. pneumophila isolation from water samples was found as 10.1%. Serological typing of 142 Legionella isolates by latex agglutination test revealed that strains belonging to L. pneumophila serogroups 2−14 predominated in the examined samples (85%), while strains of L. pneumophila serogroup 1 were less numerous (15%). According to our knowledge, our study with the greatest number of water samples from Turkey demonstrates that L. pneumophila serogroups 2−14 is the most common isolate. Rapid isolation of L. pneumophila from environmental water samples is essential for the investigation of travel related outbreaks and the possible resources. Further studies are needed to have epidemiological data and to determine the types of L. pneumophila isolates from Turkey.
Show more [+] Less [-]Distribution, sources, and potential risk of polycyclic aromatic hydrocarbons in soils from an industrial district in Shanxi, China Full text
2017
Jiao, Haihua | Bian, Gaopeng | Chen, Xi | Wang, Suiliang | Zhuang, Xuliang | Bai, Zhihui
Concentration, composition profile, orientation distribution, sources, and potential risks of 16 polycyclic aromatic hydrocarbons (PAHs) were analyzed in 76 surface (0–25 cm) soil samples collected from the Changzhi industrial district in July 2014 using a gas chromatography mass spectrometer (GC-MS QP2010 Ultra) system. The composition patterns of the PAHs were dominated by the presence of four-ring PAHs (average 42.9%), followed by three-ring (average 25.9%), five-ring PAHs (average 25.6%), two-ring PAHs (average 5.03%), and lastly, six-ring PAHs (average 0.641%). Source apportionment of the soil PAHs was also performed by the diagnostic ratios, principal component analysis (PCA), and coefficient of divergence (CD) analysis indicated signatures of PAHs sources (including incineration, coal/wood combustion, and vehicular exhaust emission). The total concentration of 16 PAHs (∑16PAHs) found in the roadsides soils (RS) ranged from 2197 to 25,041 μg kg⁻¹, with an arithmetic mean value of 12,245 μg kg⁻¹; followed by the village soils (VS), which ranged from 2059 to 21,240 μg kg⁻¹, with a mean of 8976 μg kg⁻¹; and lastly, the agricultural soils (AS), which ranged from 794 to 16,858 μg kg⁻¹, with a mean of 3456 μg kg⁻¹. According to the numerical effect-based soils quality guidelines of Maliszewska-Kordybach, the levels of PAHs in the sampled industrial areas range from high to heavy contamination. The values of total benzo[a]pyrene toxicity equivalent values (∑Bapeq16PAHs) in the sample areas ranged from 0.087 to 3611 μg kg⁻¹ with an average of 969 μg kg⁻¹. According to the soil quality guidelines of Canada, values found in the highest range (100 μg kg⁻¹), which are equal to those of ∑Bapeq16PAHs found in the industrial area samples, will exert adverse biological effects. The results of this research could potentially be useful for local governments to control toxicity exposure, promote actions to alleviate PAHs contamination, and to manage human health at both work and industrial areas.
Show more [+] Less [-]Effects of maize stover and its derived biochar on greenhouse gases emissions and C-budget of brown earth in Northeast China Full text
2017
Yang, Xu | Lan, Yu | Meng, Jun | Chen, Wenfu | Huang, Yuwei | Cheng, Xiaoyi | He, Tianyi | Cao, Ting | Liu, Zunqi | Jiang, Linlin | Gao, Jiping
Concerns regarding rising population levels and the impacts of atmospheric greenhouse gas (GHG) emissions on world climate have encouraged effective alternative methods to increase agricultural production while mitigating climate change. Soil GHG emissions from maize (Zea mays L.) fields treated with stover and a stover-derived biochar amendment during two consecutive maize growing seasons were studied in a brown earth soil type in Liaoning, China. We considered three treatments: CK (basal application of mineral NPK fertilizer; 120 kg N ha⁻¹, 60 kg P₂O₅ ha⁻¹, and 60 kg K₂O ha⁻¹, respectively), ST (maize stover application; 7.5 t ha⁻¹), and BC (7.5 t ha⁻¹ of maize stover was charred, with a yield of 35% of the original biomass; 2.63 t ha⁻¹). Both ST and BC treatments received the same fertilization as CK. Soil GHG emissions were monitored using the static chamber-gas chromatography method. The mean CO₂ emissions of the two-year experiment indicated that ST and BC were significantly higher than CK by 131.0 and by 21.3%, respectively, and there was a striking difference between ST and BC treatments. The N₂O-N emissions decreased in the following order, BC < ST < CK, and cumulative reduced CH₄ emissions in BC and ST were 1.58 and 2.21 times higher than observations in CK, respectively. The total global warming potential (GWP) in 2013 and 2014 decreased in the following order: BC < ST < CK. For the yield average data of two-year experiment, compared to CK and BC treatments, ST treatment showed 7.9 and 4.5% reduction, respectively. The C gains in BC treatment were significantly higher than that observed in ST treatment by 7.3%. Compared with the stover incorporating, biochar application significantly decreased the total CO₂ emissions and GHG intensity (GHGI), and it enhanced C-sequestration.
Show more [+] Less [-]Field crops (Ipomoea aquatica Forsk. and Brassica chinensis L.) for phytoremediation of cadmium and nitrate co-contaminated soils via rotation with Sedum alfredii Hance Full text
2017
Tang, Lin | Luo, Weijun | Chen, Weikang | He, Zhenli | Gurajala, Hanumanth Kumar | Hamid, Yasir | Deng, Meihua | Yang, Xiaoe
Phytoremediation coupled with crop rotation (PCC) is a feasible strategy for remediation of contaminated soil without interrupting crop production. The objective of this study was to develop a PCC technology system for greenhouse fields co-contaminated with Cd and nitrate using hyperaccumulator Sedum alfredii. In this system, endophytic bacterium M002 inoculation, CO₂ fertilization, and fermentation residue were continuously applied to improve the growth of S. alfredii, and low-accumulator Ipomoea aquatica and low-accumulator Brassica chinensis were rotated under reasonable water management. These comprehensive management practices were shown to increase S. alfredii biomass and Cd uptake and reduce Cd and nitrate concentration in I. aquatica and B. chinensis. This crop rotating system could remove 56.5% total Cd, 62.3% DTPA extractable Cd, and 65.4% nitrate, respectively, from the co-contaminated soil in 2 years of phytoremediation, and is an effective way of remediating moderately co-contaminated soil by Cd and nitrate.
Show more [+] Less [-]Release of polyester and cotton fibers from textiles in machine washings Full text
2017
Sillanpää, Markus | Sainio, Pirjo
Microplastics are widely spread in the environment, which along with still increasing production have aroused concern of their impacts on environmental health. The objective of this study is to quantify the number and mass of two most common textile fibers discharged from sequential machine washings to sewers. The number and mass of microfibers released from polyester and cotton textiles in the first wash varied in the range 2.1 × 10⁵ to 1.3 × 10⁷ and 0.12 to 0.33% w/w, respectively. Amounts of released microfibers showed a decreasing trend in sequential washes. The annual emission of polyester and cotton microfibers from household washing machines was estimated to be 154,000 (1.0 × 10¹⁴) and 411,000 kg (4.9 × 10¹⁴) in Finland (population 5.5 × 10⁶). Due to the high emission values and sorption capacities, the polyester and cotton microfibers may play an important role in the transport and fate of chemical pollutants in the aquatic environment.
Show more [+] Less [-]Monitoring of organic pollutants in marine environment by semipermeable membrane devices and mussels: accumulation and biochemical responses Full text
2017
Okay, Oya S. | Karacık, Burak | Güngördü, Abbas | Yılmaz, Atilla | Koyunbaba, Nazmi C. | Yakan, Sevil D. | Henkelmann, Bernhard | Schramm, Karl-Werner | Ozmen, Murat
This study involves the monitoring of organic pollutants using transplanted mussels (Mytilus galloprovincialis) as bioindicator organisms and semipermeable membrane devices (SPMDs) as passive samplers. Mussels and SPMDs were deployed to marinas, shipyards and shipbreaking yards on the coastal area of Turkey and retrieved after 60 days. Polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB) and organochlorine pesticide (OCP) compounds were analysed with high-resolution GC-MS. Total PAH concentrations in SPMDs and mussels ranged from 200 to 4740 ng g sampler⁻¹ and from 7.0 to 1130 ng g⁻¹ in wet weight (ww). PCB and OCP concentrations in SPMDs changed between 0.04–200 and 4.0–26 ng g sampler⁻¹, respectively. The highest PCB (190 ng g⁻¹ ww) and OCP (200 ng g⁻¹ ww) concentrations in mussels were measured at shipyard stations. A strong correlation was observed between the PAH and PCB concentrations in SPMDs and mussels. Enzyme assays (acetylcholinesterase, ethoxyresorufin-O-deethylase, glutathione S-transferase, glutathion reductase and carboxylesterase activities) were performed as biomarkers to reveal the effects of pollution on the mussels. There was no clear relationship found between the enzyme levels and the pollutant concentrations in mussels. Integrated biomarker responses were calculated to interpret the overall effect of pollutants.
Show more [+] Less [-]