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Effects of traditional Chinese medicine residue on plant growth and soil properties: a case study with maize (Zea mays L.) Full text
2019
Ma, Jifu | Chen, Yiping | Zhao, Yan | Chen, Dong | Wang, Hong
Traditional Chinese medicine residue (TCMR) is the solid substances remaining after the extraction of pharmaceutical ingredients from medicinal plant materials, which include abundant soil nutrients. However, TCMR is nearly lost as domestic garbage, which not only occupies a large amount of land but also leads to the waste of resource, as well as causing the eco-environment potential pollution. Therefore, we implemented this study to assess whether TCMR could be used as an organic fertilizer in agricultural practices for realizing waste resource utilization, improving soil fertility, and enhancing plant growth. The results showed that (1) application of TCMR could improve soil fertility, particularly in enhancing the soil contents of SOM, TN, NaOH-N, NaHCO₃-P, and HNO₃-K; (2) the higher application ratios of TCMR (0.8–1.0%) that increased the soil EC values would cause the risk of soil secondary salinization; (3) the lower application ratios of TCMR (0.2–0.6%) has a better positive effect on improved the maize seedlings’ physiological parameters and photosynthetic performance than the higher application ratios; (4) although application of TCMR lead to the heavy metal (Cr, Pb, Cd, As, and Hg) content increased in soil, there was no ecology risk under below 0.8% application ratio, compared with the China soil risk control standards, geo-accumulation index (Igₑₒ), and pollution load index (PLI). Thus, TCMR could potentially be used as an organic fertilizer in agricultural practices. This approach is an effective strategy not only for achieving TCMR disposal but also for realizing waste resource utilization, as well as for improving soil fertility and plant growth.
Show more [+] Less [-]Mercury chloride exposure induces DNA damage, reduces fertility, and alters somatic and germline cells in Drosophila melanogaster ovaries Full text
2019
Mojica-Vázquez, Luis Humberto | Madrigal-Zarraga, Diana | García-Martínez, Rocío | Boube, Muriel | Calderón-Segura, María Elena | Oyallon, Justine
Mercury exposure has been shown to affect the reproductive system in many organisms, although the molecular mechanisms are still elusive. In the present study, we exposed Drosophila melanogaster Canton-S adult females to concentrations of 0 mM, 0.1 mM, 0.3 mM, 3 mM, and 30 mM of mercury chloride (HgCl₂) for 24 h, 48 h, or 72 h to determine how mercury could affect fertility. Alkaline assays performed on dissected ovaries showed that mercury induced DNA damage that is not only dose-dependent but also time-dependent. All ovaries treated for 72 h have incorporated mercury and exhibit size reduction. Females treated with 30 mM HgCl₂, the highest dose, had atrophied ovaries and exhibited a drastic 7-fold reduction in egg laying. Confocal microscopy analysis revealed that exposure to HgCl₂ disrupts germinal and somatic cell organization in the germarium and leads to the aberrant expression of a germline-specific gene in somatic follicle cells in developing egg chambers. Together, these results highlight the potential long-term impact of mercury on germline and ovarian cells that might involve gene deregulation.
Show more [+] Less [-]Pure ultra-fine carbon particles do not exert pro-coagulation and inflammatory effects on microvascular endothelial cells Full text
2019
Dinmohammadi, Hossein | Pirdel, Zahra | Salarilak, Laleh | Hoylaerts, Marc | Nejatbakhsh, Reza | Biglari, Alireza | Jacquemin, Marc | Shahani, Tina
Pro-thrombotic and inflammatory changes play an important role in cardiovascular morbidity and mortality, resulting from short-term exposure to fine particulate air-pollution. Part of those effects has been attributed to the ultra-fine particles (UFPs) that pass through the lung and directly contact blood-exposed and circulating cells. Despite UFP-induced platelet activation, it is unclear whether the penetrated particles exert any direct effect on endothelial cells. While exposure levels are boosting as a result of world-wide increases in economic development and desertification, which create more air-polluted regions, as well as increase in demands for synthetic UFPs in medicine and various industries, further studies on the health effects of these particles are required. In this study, human pulmonary and cardiac microvascular endothelial cells (MECs) have been exposed to 0.1, 1, 10, and 100 μg/ml suspensions of either a natural (carbon black) or a synthetic (multi-walled carbon nano-tubes) type of UFPs, in vitro. As a result, no changes in the levels of coagulation factor VIII, Von Willebrand factor, Interleukin 8, and P-selectin measured in the cells’ supernatant were observed prior to and 6, 12, and 24 h after exposure. In parallel, the spatio-temporal effect of UFPs on cardiac MECs was evaluated by Transmission Electron Microscopy. Despite phagocytic uptake of pure UFPs observed on cellular sections of the treated cells, Weibel-Palade bodies remained intact in shape and similar in number when compared with the untreated cells. Our work shows that carbon itself is a non-toxic carrier for endothelial cells.
Show more [+] Less [-]Pyrene degradation by marine-derived ascomycete: process optimization, toxicity, and metabolic analyses Full text
2019
Vasconcelos, Maria R. S. | Vieira, Gabriela A. L. | Otero, Igor V. R. | Bonugli-Santos, Rafaella C. | Rodrigues, Marili V. N. | Rehder, Vera L. G. | Ferro, Milene | Boaventura, Sinésio | Bacci, Maurício Jr | Sette, Lara D.
Marine-derived fungi are relevant genetic resources for bioremediation of saline environments/processes. Among the five fungi recovered from marine sponges able to degrade pyrene (Py) and benzo[a]pyrene (BaP), Tolypocladium sp. strain CBMAI 1346 and Xylaria sp. CBMAI 1464 presented the best removal rates of Py and BaP, respectively. Since the decrease in BaP was related to mycelial adsorption, a combined strategy was applied for the investigation of Py degradation by the fungus Tolypocladium sp. CBMAI 1346. The selected fungus was able to degrade about 95% of Py after 7 days of incubation (optimized conditions), generating metabolites different from the ones found before optimization. Metabolites and transcriptomic data revealed that the degradation occurred mainly by the cytochrome P450 pathway. Putative monooxygenases and dioxygenases found in the transcriptome may play an important role. After 21 days of degradation, no toxicity was found in the optimized culture conditions. The findings from the present study highlight the potential of marine-derived fungi to degrade environmental pollutants and convey innovative information related to the metabolism of pyrene.
Show more [+] Less [-]Synergistic effect of TiO2-CuWO4 on the photocatalytic degradation of atrazine Full text
2019
He, Dewen | Yang, Yang | Tang, Jianjun | Zhou, Kanggen | Chen, Wei | Chen, Yiqing | Dong, Zijun
In this work, CuWO₄ is prepared and its effect of improving photocatalytic degradation of atrazine by TiO₂ as well as the synergetic mechanism is studied. Results show that the addition of CuWO₄ (50 mg/L) into the reaction system can significantly enhance the efficiency of atrazine degradation, resulting in an increased degradation efficiency of 92.1% after 270 min, which is 1.94 times higher than that of the single TiO₂. As the sintering temperate of CuWO₄ was increased, the degradation efficiency of atrazine increased initially and then deceased after reaching a maximum at 500 °C. The origin of the synergistic effect of TiO₂-CuWO₄ is attributed to the introduction of solid CuWO₄. The photochemical test results indicate that the photogenerated electrons transfer from irradiated TiO₂ to CuWO₄, which is beneficial to the O₂ reduction and H₂O₂ formation in aqueous solution thus promoting the photocatalytic activity of TiO₂. These observations unveil the importance of improving photocatalytic activity of TiO₂ with Cu-bearing semiconductors.
Show more [+] Less [-]Mutual effects behind the simultaneous removal of toxic metals and cationic dyes by interlayer-expanded MoS2 nanosheets Full text
2019
Wu, Zheng | Duan, Qingyun | Li, Xuede | Li, Jie
Simultaneous removal of coexisting metals and dyes from industrial wastewaters is challenging, and the mutual effects behind the co-adsorption of these pollutants remain unclear. Herein, interlayer-expanded MoS₂ (IE-MoS₂) nanosheets prepared by a one-pot simple and scalable method were tested to simultaneously remove toxic metals and cationic dyes. The adsorption capacities of IE-MoS₂ nanosheets were 499, 423, 500, 355, and 276 mg/g for Pb(II), Cu(II), methylene blue, malachite green, and rhodamine B, respectively, in a mono-contaminant system. Interestingly, the sequestration amount of Pb(II) was dependent on the concentrations of dyes in the binary Pb(II)−dye systems, while uptake of cationic dyes was almost not influenced by coexisting Pb(II). The simultaneous adsorption mechanism was further confirmed by spectroscopic methods. The IE-MoS₂ nanosheets were easily regenerated and reused for six adsorption−desorption cycles without structure destruction, thus avoiding the potential hazards of nanomaterial to the ecosphere. More interestingly, high-efficiency uptake of Pb(II) from intentionally contaminated natural water and model textile effluent was obtained by using a column filled with IE-MoS₂ nanosheets. In summary, IE-MoS₂ nanosheets with facile and scalable synthesis method, efficient adsorption performance, and excellent reusability showed potential promise for the integrative treatment of complex wastewater bearing both metals and organic pollutants.
Show more [+] Less [-]Pilot-scale application of a single-stage hybrid airlift BioCAST bioreactor for treatment of ammonium from nitrite-limited wastewater by a partial nitrification/anammox process Full text
2019
Saborimanesh, Nayereh | Walsh, David | Yerushalmi, Laleh | Arriagada, Esteban Castillo | Mulligan, Catherine N.
This paper presents the treatment of a nitrite-limited wastewater by partial nitrification/anammox process under different dissolved oxygen (DO) concentrations of < 1.2 mg/L, < 0.5 mg/L, and 0 mg/L, and at temperatures of 35 to 27 °C in a pilot-scale single-stage hybrid bioreactor (BioCAST). The effect of operational parameters on microbial community structure and composition has also been investigated during the 1-year experimental period. Ammonium removal efficiencies of 73 ± 19% at 35–32 °C and 87 ± 9% at 29–27 °C were obtained from a synthetic nitrite-limited wastewater with ammonium concentration of 350–500 mg/L (175–250 g m⁻³ d⁻¹). The adaptation of bacteria to a lower temperature (27 °C) and lower free ammonia concentrations at 27 °C was showed to be key factors leading to the optimal nitrite production by aerobic ammonium-oxidizing bacteria (AOB). No nitrite accumulation was observed due to the effective distribution and transfer of nitrite produced by the AOB in the aerobic zone to the microaerophilic/anoxic zones. The fast enrichment of Candidatus species in the suspended biomass in the anoxic zone at temperatures of 35–30 °C and in the attached biofilm in the microaerophilic zone (DO < 0.5 mg/L) at 29–27 °C suggests that the growth media (e.g., suspended biomass vs attached biofilm) had a minor effect on the diversity of microbial community in this bioreactor. This study supports the effective treatment of nitrite-limited wastewater with ammonium concentrations of < 500 mg/L by partial nitrification/anammox process at 35–27 °C in a single-stage hybrid bioreactor by adjusting the DO concentration to < 0.5 mg/L and by providing longer retention times for aerobic (AOB) and anammox bacteria in the biofilm, which resulted in the long-term suppression of nitrite-oxidizing bacteria (NOB).
Show more [+] Less [-]Comparison of biochar- and activated carbon-supported zerovalent iron for the removal of Se(IV) and Se(VI): influence of pH, ionic strength, and natural organic matter Full text
2019
Tan, Guangcai | Mao, Yi | Wang, Hongyuan | Junaid, Muhammad | Xu, Nan
Biochar (BC) and activated carbon (AC) were both produced from corn straw. Biochar-supported zerovalent iron (BC-ZVI) and activated carbon-supported zerovalent iron (AC-ZVI) were synthesized and applied for Se(IV)/Se(VI) removal. The sorption capacity of BC-ZVI for Se(IV) and Se(VI) was reported at 62.52 and 35.39 mg g⁻¹, higher than that of AC-ZVI (56.02 and 33.24 mg g⁻¹), respectively, due to its higher iron content and more positive charges. The spectroscopic analyses showed that Se(IV)/Se(VI) were reduced to Se(0)/Se(-II) of less toxicity and solubility. The effects of various factors such as pH, ionic strength, co-existing cations and anions, and natural organic matter (NOM) were also investigated. Ionic strength showed no significant effect on Se(IV)/Se(VI) removal, but pH was critical. The presence of NO₃⁻ and SO₄²⁻ did not cause obvious inhibition to the removal, while PO₄³⁻ inhibited the sorption capacity of BC-ZVI and AC-ZVI for Se(IV)/Se(VI) significantly. Common cations (K⁺, Ca²⁺, and Mg²⁺) were found to slightly enhance the removal, while NOM significantly decreased the sorption capacity of BC-ZVI and AC-ZVI for Se(IV)/Se(VI). Besides, NOM showed stronger inhibition effect on AC-ZVI than that on BC-ZVI. These results indicated that BC-ZVI, compared with AC-ZVI, could be a promising sorbent to remove Se(IV)/Se(VI) due to its low cost and high efficiency.
Show more [+] Less [-]Effective cleanup of oil contamination on bio-inspired superhydrophobic surface Full text
2019
Zhou, Qin | Wang, Leyang | Xu, Qi | Zhao, Yuan
The oil-water separation is a popular issue and the removal of oil from bulk water is also meaningful especially in oil spill incident, which not only wastes valuable energy resources but also threatens the ecological system and human health. Superhydrophobic and superoleophilic materials are very promising for the efficient oil removal from bulk water. Reported herein was a novel and easily operated superhydrophobic surface dip coating from a paint-like suspension containing two different sizes TiO₂ and perfluorooctyltriethoxysilane. Aluminum foil substrate, which is flexile and cost-efficient, was bonded with commercial water-proof double-sided adhesive tape (DSAT) to fix the paint to improve the mechanical strength. The coated aluminum foil exhibited rapid sorption/desorption rate (267 L/h m²), high oil sorption capacity (21 g/g), and excellent recyclability (≫ 15 recycling times). After 15 recycling times of sorption/desorption, the coated surface morphology still remained hierarchical micro- and nanostructures and the water contact angle still reached ~ 150°, indicating its superhydrophobic property. Meanwhile, the cost of oil removal of the coated material can match that of the commercial sorbent. We anticipate that the coated superhydrophobic aluminum foil will show outstanding performances on oil absorption and have good applications on a large scale.
Show more [+] Less [-]Magnetic diatomite for pesticide removal from aqueous solution via hydrophobic interactions Full text
2019
Erol, Kadir | Yıldız, Emrecan | Alacabey, İhsan | Karabörk, Muharrem | Uzun, Lokman
Pesticides are highly hazardous chemicals for the environment and human health and their use in agriculture is constantly increasing. Although 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane 4,4′-DDT was banned at developed countries, it is still one of the most dangerous of chemical due to accumulation in the environment. It is known that the toxicity of DDT affects some enzyme systems biochemically. The main motivation of this study is to develop an effective adsorbate for the removal DDT, which was chosen as a model hydrophobic pesticide, out of aqueous systems. For this purpose, the bare diatomite particles were magnetically modified and a hydrophobic ligand attached to enhance its adsorptive and physio-chemical features. Under optimal conditions, a high adsorption capacity, around 120 mg/g with the hydrophobic and magnetic diatomite particles, modification of the diatomite particles reduced average pores diameter whereas surface area and total pore volume increased (around 15-folds). After five consecutive adsorption–desorption cycles, no significant decrease in adsorption capability was observed. The adsorption isotherms (Langmuir, Freundlich, and Flory–Huggins) applied to the data indicated that the adsorption process occurred via monolayer adsorption in an entropy-driven manner. The kinetic data also revealed the quick adsorption process without any diffusion limitations. Graphical Abstract
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