共查询到20条相似文献,搜索用时 697 毫秒
1.
Yu YANG Zhicheng YU Takayuki NOSAKA Kyle DOUDRICK Kiril HRISTOVSKI Pierre HERCKES Paul WESTERHOFF 《Frontiers of Environmental Science & Engineering》2015,9(5):823
Increasing production and use of carbonaceous nanomaterials (NMs) will increase their release to the sewer system and to municipal wastewater treatment plants. There is little quantitative knowledge on the removal of multi-walled carbon nanotubes (MWCNTs), graphene oxide (GO), or few-layer graphene (FLG) from wastewater into the wastewater biomass. As such, we investigated the quantification of GO and MWCNTs by UV-Vis spectrophotometry, and FLG using programmable thermal analysis (PTA), respectively. We further explored the removal of pristine and oxidized MWCNTs (O-MWCNTs), GO, and FLG in a biomass suspension. At least 96% of pristine and O-MWCNTs were removed from the water phase through aggregation and 30-min settling in presence or absence of biomass with an initial MWCNT concentration of 25 mg·L−1. Only 65% of GO was removed with biomass concentration at or above 1,000 mg·L−1 as total suspended solids (TSS) with the initial GO concentration of 25 mg·L−1. As UV-Vis spectrophotometry does not work well on quantification of FLG, we studied the removal of FLG at a lower biomass concentration (50 mg TSS·L−1) using PTA, which showed a 16% removal of FLG with an initial concentration of 1 mg·L−1. The removal data for GO and FLG were fitted using the Freundlich equation (R2 = 0.55, 0.94, respectively). The data presented in this study for carbonaceous NM removal from wastewater provides quantitative information for environmental exposure modeling and life cycle assessment. 相似文献
2.
Jingya SHEN Yuliang SUN Liping HUANG Jinhui YANG 《Frontiers of Environmental Science & Engineering》2015,9(6):1084-1095
Cobalt and copper recovery from aqueous Co(II) and Cu(II) is one critical step for cobalt and copper wastewaters treatment. Previous tests have primarily examined Cu(II) and Co(II) removal in microbial electrolysis cells (MECs) with abiotic cathodes and driven by microbial fuel cell (MFCs). However, Cu(II) and Co(II) removal rates were still slow. Here we report MECs with biocathodes and driven by MFCs where enhanced removal rates of 6.0±0.2 mg?L−1?h−1 for Cu(II) at an initial concentration of 50 mg?L−1 and 5.3±0.4 mg?L−1 h−1 for Co(II) at an initial 40 mg?L−1 were achieved, 1.7 times and 3.3 times as high as those in MECs with abiotic cathodes and driven by MFCs. Species of Cu(II) was reduced to pure copper on the cathodes of MFCs whereas Co(II) was removed associated with microorganisms on the cathodes of the connected MECs. Higher Cu(II) concentrations and smaller working volumes in the cathode chambers of MFCs further improved removal rates of Cu(II) (115.7 mg?L−1?h−1) and Co(II) (6.4 mg?L−1?h−1) with concomitantly achieving hydrogen generation (0.05±0.00 mol?mol−1 COD). Phylogenetic analysis on the biocathodes indicates Proteobacteria dominantly accounted for 67.9% of the total reads, followed by Firmicutes (14.0%), Bacteroidetes (6.1%), Tenericutes (2.5%), Lentisphaerae (1.4%), and Synergistetes (1.0%). This study provides a beneficial attempt to achieve simultaneous enhanced Cu(II) and Co(II) removal, and efficient Cu(II) and Co(II) wastewaters treatment without any external energy consumption. 相似文献
3.
Xinwei LI Hanchang SHI Kuixiao LI Liang ZHANG 《Frontiers of Environmental Science & Engineering》2015,9(6):1076-1083
The effluent of a wastewater treatment plant was treated in a pilot plant for reclaimed water production through the denitrification biofilter (DNBF) process, ozonation (O3), and biologic aerated filtration (BAF). The combined process demonstrated good removal performance of conventional pollutants, including concentrations of chemical oxygen demand (27.8 mg·L−1) and total nitrogen (9.9 mg·L−1) in the final effluent, which met the local discharge standards and water reuse purposes. Micropollutants (e.g., antibiotics and endocrine-disrupting chemicals) were also significantly removed during the proposed process. Ozonation exhibited high antibiotic removal efficiencies, especially for tetracycline (94%). However, micropollutant removal efficiency was negatively affected by the nitrite produced by DNBF. Acute toxicity variations of the combined process were estimated by utilizing luminescent bacteria. Inhibition rate increased from 9% to 15% during ozonation. Carbonyl compound concentrations (e.g., aldehydes and ketones) also increased by 58% as by-products, which consequently increased toxicity. However, toxicity eventually became as low as that of the influent because the by-products were effectively removed by BAF. The combined DNBF/O3/BAF process is suitable for the advanced treatment of reclaimed water because it can thoroughly remove pollutants and toxicity. 相似文献
4.
Removing phosphorus from aqueous solutions by using iron-modified corn straw biochar 总被引:1,自引:0,他引:1
Fenglin LIU Jiane ZUO Tong CHI Pei WANG Bo YANG 《Frontiers of Environmental Science & Engineering》2015,9(6):1066-1075
Iron-modified corn straw biochar was used as an adsorbent to remove phosphorus from agricultural runoff. When agricultural runoffs with a total phosphorus (TP) concentration of 1.86 mg·L−1 to 2.47 mg·L−1 were filtered at a hydraulic retention time of 2 h through a filtration column packed with the modified biochar, a TP removal efficiency of over 99% and an effluent TP concentration of less than 0.02 mg·L−1 were achieved. The isotherms of the phosphorus adsorption by the modified biochar fitted the Freundlich equation better than the Langmuir equation. The mechanism of the phosphorus adsorbed by the modified biochar was analyzed by using various technologies, i.e. scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FTIR). The results indicated that the surface of the modified biochar was covered by small iron granules, which were identified as Fe3O4. The results also showed that new iron oxides were formed on the surface of the modified biochar after the adsorption of phosphorus. Moreover, new bonds of Fe-O-P and P-C were found, which suggested that the new iron oxides tend to be Fe5(PO4)4(OH)3. Aside from removing phosphorus, adding the modified biochar into soil also improved soil productivity. When the modified biochar-to-soil rate was 5%, the stem, root, and bean of broad bean plants demonstrated increased growth rates of 91%, 64%, and 165%, respectively. 相似文献
5.
Chengyuan SU Weiguang LI Xingzhe LIU Xiaofei HUANG Xiaodan YU 《Frontiers of Environmental Science & Engineering》2016,10(1):37-45
A study of the decolorization of reactive brilliant blue in an aqueous solution using Fe-Mn-sepiolite as a heterogeneous Fenton-like catalyst has been performed. The Fourier transform infrared (FTIR) spectra of the catalyst showed bending vibrations of the Fe-O. The X-ray diffraction (XRD) patterns of the catalyst showed characteristic diffraction peaks of α-Fe2O3, γ-Fe2O3 and MnO. A four factor central composite design (CCD) coupled with response surface methodology (RSM) was applied to evaluate and optimize the important variables (catalyst addition, hydrogen peroxide dosage, initial pH value and initial dye concentration). When the reaction conditions were catalyst dosage= 0.4 g, [H2O2]= 0.3 mL, pH= 2.5, [reactive brilliant blue]o = 50 mg·L−1, and volume of solution= 500 mL at room temperature, the decolorization efficiency of reactive brilliant blue was 91.98% within 60 min. Moreover, the Fe-Mn-sepiolite catalyst had good stability for the degradation of reactive brilliant blue even after six cycles. Leaching of iron ions (<0.4 mg·L−1) was observed. The decoloring process was reactive brilliant blue specific via a redox reaction. The benzene ring and naphthalene ring were first oxidized to open ring; these were then oxidized to the alcohol and carboxylic acid. The reactive brilliant blue was decomposed mainly by the attack of ·OH radicals including surface-bound ·OH radicals generated on the catalyst surface. 相似文献
6.
Yongtao LV Xuan CHEN Lei WANG Kai JU Xiaoqiang CHEN Rui MIAO Xudong WANG 《Frontiers of Environmental Science & Engineering》2016,10(2):390
Microsensor measurements and fluorescence in situ hybridization (FISH) analysis were combined to investigate the microbial populations and activities in a laboratory-scale sequencing batch reactor (SBR) for completely autotrophic nitrogen removal over nitrite (CANON). Fed with synthetic wastewater rich in ammonia, the SBR removed 82.5±5.4% of influent nitrogen and a maximum nitrogen-removal rate of 0.52 kgN·m−3·d−1 was achieved. The FISH analysis revealed that aerobic ammonium-oxidizing bacteria (AerAOB) Nitrosomonas and anaerobic ammonium-oxidizing bacteria (AnAOB) dominated the community. To quantify the microbial activities inside the sludge aggregates, microprofiles were measured using pH, dissolved oxygen (DO), NH 4 + , N O 2 − and N O 3 − microelectrodes. In the outer layer of sludge aggregates (0–700 μm), nitrite-oxidizing bacteria (NOB) showed high activity with 4.1 μmol·cm−3·h−1 of maximum nitrate production rate under the condition of DO concentration higher than 3.3 mg·L−1. Maximum AerAOB activity was detected in the middle layer (depths around 1700 μm) where DO concentration was 1.1 mg·L−1. In the inner layer (2200–3500 μm), where DO concentration was below 0.9 mg·L−1, AnAOB activity was detected. We thus showed that information obtained from microscopic views can be helpful in optimizing the SBR performance. 相似文献
7.
Jianguo LIU Hui CAI Congcong MEI Mingxin WANG 《Frontiers of Environmental Science & Engineering》2015,9(5):905
The current study investigated the effects of nano-silicon (Si) and common Si on lead (Pb) toxicity, uptake, translocation, and accumulation in the rice cultivars Yangdao 6 and Yu 44 grown in soil containing two different Pb levels (500 mg·kg−1 and 1000 mg·kg−1). The results showed that Si application alleviated the toxic effects of Pb on rice growth. Under soil Pb treatments of 500 and 1000 mg·kg−1, the biomasses of plants supplied with common Si and nano-Si were 1.8%–5.2% and 3.3%–11.8% higher, respectively, than those of plants with no Si supply (control). Compared to the control, Pb concentrations in rice shoots supplied with common Si and nano-Si were reduced by 14.3%–31.4% and 27.6%–54.0%, respectively. Pb concentrations in rice grains treated with common Si and nano-Si decreased by 21.3%–40.9% and 38.6%–64.8%, respectively. Pb translocation factors (TFs) from roots to shoots decreased by 15.0%–29.3% and 25.6%–50.8%, respectively. The TFs from shoots to grains reduced by 8.3%–13.7% and 15.3%–21.1%, respectively, after Si application. The magnitudes of the effects observed on plants decreased in the following order: nano-Si treatment>common Si treatment and high-grain-Pb-accumulating cultivar (Yangdao 6)>low-grain-Pb-accumulating cultivar (Yu 44) and heavy Pb stress (1000 mg·kg−1)>moderate Pb stress (500 mg·kg−1)>no Pb treatment. The results of the study indicate that nano-Si is more efficient than common Si in ameliorating the toxic effects of Pb on rice growth, preventing Pb transfer from rice roots to aboveground parts, and blocking Pb accumulation in rice grains, especially in high-Pb-accumulating rice cultivars and in heavily Pb-polluted soils. 相似文献
8.
Genotype variations in accumulation of cadmium and lead in celery (Apium graveolens L.) and screening for low Cd and Pb accumulative cultivars 总被引:2,自引:0,他引:2
Kun Zhang Jianbing Wang Zhongyi Yang Guorong Xin Jiangang Yuan Junliang Xin Charlie Huang 《Frontiers of Environmental Science & Engineering》2013,7(1):85-96
To help reduce risks of heavy metal pollution, two pot experiments were conducted to investigate the variations, transfer potential, and stability of Cadmium (Cd) and Lead (Pb) accumulations in celery (Apium graveolens L.) and to screen for low Cd and Pb accumulative cultivars. The maximum differences in shoot Cd concentration were 4.7-fold under low-Cd exposure and 3.3-fold under high-Cd exposure. These genotype variations in Cd accumulation are sufficiently large to help reduce Cd contamination risk in soil by using the Low-Cd-Accumulative genotypes. Cd accumulation of the Low-Cd-Accumulative genotypes is significantly positive correlated with Pb accumulation. Evidence obtained proves that Cd and Pb accumulations in celery are stable and genotype-dependent at the cultivar level. The presence of high-Pb contamination in soil promoted Cd accumulation in shoots of celery. Celery is considered a species with high risks in Cd pollution and low risks in Pb pollution. Among the tested cultivars, cv. Shuanggangkangbing (SGKB) had the lowest shoot Cd and Pb accumulating abilities, and thus is the most important material for breeding of pollution-safe cultivars (PSCs) to minimize Cd and Pb accumulations in celery. 相似文献
9.
W. James Catallo W. Henk L. Younger O. Mills D. J. Thiele S. P. Meyers 《Chemistry and Ecology》1996,13(2):113-131
The ascosporogenous marine yeast Pichia spartinae is a dominant endosymbiont of the marsh grass Spartina alterniflora. Results of previous studies suggested that P. spartinae is involved in iron transport processes in the grass. of particular interest has been the mechanisms of metal uptake and metabolism by the yeast, and the ecological and plant biochemical significance of these processes. This investigation examined the uptake of iron and other metals (Zn, Cu, Cd, Ni, Pb, Cr) by P. spartinae, and provides data on possible mechanisms of this activity. the results suggest a) the yeast can assimilate divalent and trivalent forms of inorganic iron, as well as large organic-Fe(III) complexes, b) the uptake of inorganic trivalent iron under soluble iron-deficient conditions proceeded by a different mechanism than that of soluble Fe(II), with intracellular loadings of iron much increased under the former conditions; c) trivalent iron uptake is not mediated by hydroxamate siderophores at levels detectable by sensitive screening assays; d) the assimilation of some trace metals (Cu, Zn, Cd, Ni) is likely to be mediated by low molecular weight cysteine rich proteins, possibly metallothionein, and; e) siderophores from other fungi can provide iron for P. spartinae. the iron assimilation data suggested that multiple mechanisms are involved, and are influenced by the concentration and speciation of iron in the system. in general, iron assimilation mechanisms are comparable to those described for closely related yeasts, such as Saccharomyces cerevisiae. Among other things, these results indicated that future studies of trace metal mobilization and plant assimilation in salt marsh ecosystems must account for the activities of microbial symbionts associated with the plants. 相似文献
10.
Lin LIU Qiyu YOU Valerie GIBSON Xu HUANG Shaohua CHEN Zhilong YE Chaoxiang LIU 《Frontiers of Environmental Science & Engineering》2015,9(6):1139-1148
The granulation process, physic-chemical properties, pollution removal ability and bacterial communities of aerobic granules with different feed-wastewater (synthetic wastewater, R1; swine wastewater, R2), and the change trend of some parameters of two types of granules in long-term operated reactors treating swine wastewater were investigated in this experiment. The result indicated that aerobic granulation with the synthetic wastewater had a faster rate compared with swine wastewater and that full granulation in R1 and R2 was reached on the 30th day and 39th day, respectively. However, although the feed wastewater also had an obvious effect on the biomass fraction and extracellular polymeric substances of the aerobic granules during the granulation process, these properties remained at a similar level after long-term operation. Moreover, a similar increasing trend could also be observed in terms of the nitrogen removal efficiencies of the aerobic granules in both reactors, and the average specific removal rates of the organics and ammonia nitrogen at the steady-state stage were 35.33 mg·g−1 VSS and 51.46 mg·g−1 VSS for R1, and 35.47 mg·g−1 VSS and 51.72 mg·g−1 VSS for R2, respectively. In addition, a shift in the bacterial diversity occurred in the granulation process, whereas bacterial communities in the aerobic granular reactor were not affected by the seed granules after long-term operation. 相似文献
11.
Discharges of nutrients, urea, dissolved organic matter and heavy metals by a sewage underwater pipeline are analysed in comparison to environmental conditions in a shallow coastal zone. Variable thermo-haline stratifications of the water column and currents in upper (2.62-34.97 cm s-1) and deeper (0.83-10.91 cm s-1) layers drive vertical diffusion and lateral transport of wastewaters. Loads of reactive phosphorus (0.13 tons d-1) and ammonium (1.62 tons d-1) by the pipeline are not negligible compared to the major river loads in the gulf. High concentrations of urea (≤11.51 μmol N dm-3) were found in the area of wastewater release. Ammonium uptake (6.14-534 nmol N dm-3 h-1) strongly exceeded nitrate uptake (0.19-138 nmol N dm-3 h-1), indicating that discharges of ammonium by the pipeline are actively assimilated by plankton community even at low levels of light. Distribution of Zn (≤27.7 ppb), Cu (≤25.6 ppb), Cd (≤0.80 ppb) and Pb (≤13.5 ppb) in the water column and the measurement of their complex-forming capacity in seawater did not indicate a persistent perturbation of the pelagic environment due to heavy metals. 相似文献
12.
This study aims to determine heavy-metal levels in soil from the banks of Lake Nasser, the ability of Tamarix nilotica to accumulate such metals from soil and hence its potential for phytoextraction. Soil and Tamarix samples were collected from the banks of four bights around Lake Nasser and analysed for Fe, Mn, Ca, Mg, Cr, Cu, Ni, Zn, Cd and Pb by atomic absorption spectrometry, whereas Na and K were measured by atomic emission spectrophotometry. Three different methods of extraction were used for the soil samples. Lead, copper and zinc were equally distributed between the exchangeable phase and Fe/Mn oxide-bound form, while other measured metals were mainly present in the Fe/Mn oxide fraction. With the exception of iron, all metals studied showed total concentrations within the geochemical background values. T. nilotica exhibited elevated concentrations of Na (36.2-48.5 mg g-1) and K (2.74-4.33 mg g-1) in stems, and relatively high concentrations of Pb, Cd and Co (0.39-1.03 µg g-1, 0.24-1.3 µg g-1 and 1.94-5.3 µg g-1, respectively) are found in plant leaves. Bioaccumulation factors of Na and K (9.3 and 12.63, respectively) were high in T. nilotica stems. While the bioaccumulation of Pb, Cd, Co and Ni (2870.1, 2035.4, 10.5 and 5313.2, respectively) was high in plant leaves, Fe, Mn, Ca and Mg were accumulated relatively equally in plant stems and leaves. T. nilotica was found to secrete high amounts of Na, Ca and K, in addition to small amounts of all accumulated metals except Cd and Cu. These secreted metals appeared as salt crystals (67.5% Na; 25.8% Ca; 5% Mg; 1.5% K and 0.16% trace and minor elements) on the plant surface. The concentrations of all the metals studied in T. nilotica were higher than in the salt crystals. Statistical analysis of the database suggests bioaccumulation of these metals from soil to T. nilotica. This reflects the importance of using T. nilotica as a model in the phytoremediation process as an established environmental clean-up technology. 相似文献
13.
Quanlin DAI Baifei HUANG Zhongyi YANG Jiangang YUAN Junzhi YANG 《Frontiers of Environmental Science & Engineering》2010,4(4):449-458
A maize variety, Huatian-1, had an unusually low translocation rate of cadmium (Cd) (59.6 mg·kg-1 in the roots and 0.093 mg·kg-1 in the grain) compared to 24 other varieties while being grown in soils with 16.50 mg·kg-1 Cd. This indicates that this particular species may have special mechanisms that affect the absorption and translocation pattern of Cd. In this paper, the technique of suppression subtractive hybridization (SSH) was used to isolate and identify Cd-induced genes from Huatian-1 hydroponically ?exposed? to? 0.1 mM ?CdCl2 ?for? 1 h,? 12 h, 24 h, and 48 h. We found a total of 15 differentially expressed genes in the four groups; 2, 3, 4, and 6 genes were from the groups of 1 h, 12 h, 24 h, and 48 h treatment, respectively. Phospholipase PLDb1 mRNA, adenosine triphosphate (ATP) phosphoribosyl transferase 2, and Sp17 were turned on in the maize in response to Cd stress, and it might provide new clues to explain the mechanism of maize tolerance to Cd. 相似文献
14.
Wagdy Labib 《Chemistry and Ecology》1996,12(3):163-170
A yellow-brown coloration of water developed in the Eastern Harbour of Alexandria (Egypt) during April 1993. the dinoflagellate Prorocentrum triestinum, the causative organism, culminated in a population peak of 71-106 cells 1-1, chlorophyll a nearly 361 μgl-1. the bloom occurred with a thermohaline stratified water column and low surface nutrient levels. Water temperature was considered a crucial environmental factor controlling the occurrence of P. triestinum and nitrate was significantly correlated with its counts. the high relative growth constant (3.4 d-1), calculated just prior to the massive occurrence of the species, explains the rapid development of the bloom. A comparison with the earlier phytoplankton studies in the harbour is made. 相似文献
15.
Yuyao ZHANG Huan LI Can LIU Yingchao CHENG 《Frontiers of Environmental Science & Engineering》2015,9(6):1108-1116
High-solids anaerobic digestion of sewage sludge was a promising process, but high solid concentration negatively influenced methane production. The influencing mechanism was systematically analyzed in this study through a series of static anaerobic digestion experiments at total solids (TS) contents of 3%–15%. The results showed that TS 6% was the boundary between low-solids and high-solids anaerobic digestion, and the accumulative methane yield decreased exponentially when TS increased from 6% to 15%. The performance of anaerobic digestion was directly determined by the efficiency of mass transfer, and the relation between methane yield and sludge diffusive coefficients was well described by a power function. Thus, the increasing TS resulted in an exponential increase in sludge viscosity but an exponential decrease in diffusive coefficient. The blocked mass transfer led to the accumulation of volatile fatty acids (VFAs) and free ammonia. Acetic metabolism was the main process, whereas butyric and propionic metabolisms occurred at the initial stage of high-solids anaerobic digestion. The concentration of VFAs reached the maximum at the initial stage, which were still lower than the threshold influencing methanogens. The concentration of free ammonia increased gradually, and the methanogenesis was inhibited when free ammonia nitrogen exceeded 50 mg·L−1. Consequently, the deterioration of high-solids anaerobic digestion was related to the blocked mass transfer and the resulting ammonia accumulation. 相似文献
16.
Zhihao Si Xinshan Song Xin Cao Yuhui Wang Yifei Wang Yufeng Zhao Xiaoyan Ge Awet Arefe Tesfahunegn 《Frontiers of Environmental Science & Engineering》2020,14(1):4
17.
Kehui Liu Jie Xu Chenglong Dai Chunming Li Yi Li Jiangming Ma Fangming Yu 《Frontiers of Environmental Science & Engineering》2021,15(5):86
18.
Yujie Pan Yalan Li Hongxia Peng Yiping Yang Min Zeng Yang Xie Yao Lu Hong Yuan 《Frontiers of Environmental Science & Engineering》2023,17(5):56
19.
20.
几种植物处理含重金属废水的适应性研究 总被引:18,自引:2,他引:18
试验采用蕹菜、油菜、美人蕉、水葫芦、水花生、水浮莲6种适应人工湿地的植物,在水培情况下研究了它们对Hg、Cd、Pb、Cr、Cu、Zn6种重金属的适应性,以综合考虑了植物的适水性与对重金属耐性的生物量为指标,得出了植物对6种重金属模拟废水综合耐性由强到弱的排序为美人蕉→水葫芦→油菜→水浮莲→蕹菜→水花生。不同植物对于其中一种重金属的单一耐性也有差异,美人蕉对Cr、Hg、Zn耐性较强,水浮莲对Pb、Cu、Cd耐性较强。植物对重金属的综合耐性和单一耐性的试验结果可为湿地处理含重金属废水提供参考。 相似文献