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14621. 题目: Temperature sensitivity of soil heterotrophic respiration is altered by carbon substrate along the development of Quercus Mongolica forest in northeast China
文章编号: N18092314
期刊: Applied Soil Ecology
作者: Xiaohan Xu, Baoshan Yang, Hui Wang, Yanan Cao, Kang Li, Shengwen Gao
更新时间: 2018-09-23
摘要: Soil heterotrophic respiration was profoundly correlated with the decomposition of soil organic carbon and the global carbon balance. It was liable to be affected by temperature and carbon substrate availability. To investigate the effects of different carbon substrate inputs on organic carbon decomposition and the temperature sensitivity of soil heterotrophic respiration along the forest stand ages, we sampled surface soils (0–20 cm) from three Quercus Mongolica forest stands (20, 30 and 40 years old) in Northeast China. The microcosms were established to incubate the soil under three carbon substrate treatments (glucose, amylopectin, and the combination of glucose and amylopectin) at 13, 23, and 33 °C, respectively. The carbon substrates were 320 μmol g−1 and 40 μmol g−1 fresh soil for glucose and amylopectin, respectively. The combined treatment was 160 μmol glucose g−1 and 20 μmol amylopectin g−1 fresh soil. The results showed that rates of basal respiration (BR), substrate-induced respiration (SIR), and specific growth rate (SGR) significantly increased with the increasing forest ages. After the addition of carbon substrates, the stimulation effects of SIR and SGR were higher at 23 °C than 13 °C and 33 °C, especially the addition of amylopectin. The Q10 values of SIR were lower after the addition of glucose than those of amylopectin at lower temperature intervals (13–23 °C), but higher at higher temperatures (23–33 °C). The Q10 linearly increased with increasing rates of substrate availability. The Q10 values of SIR stimulated by amylopectin were higher at lower temperature intervals (13–23 °C), suggesting the responses of Q10 were not only adjusted by carbon substrates but also the ranges of temperature change. The exogenous stable organic carbon inputs greatly increased the Q10 values of soil heterotrophic respiration in the older forest stands. These results indicated that the decomposition of stable carbon substrate will be more sensitivity to temperature in boreal successional Quercus Mongolica forest.

14622. 题目: Long-term application of manure over plant residues mitigates acidification, builds soil organic carbon and shifts prokaryotic diversity in acidic Ultisols
文章编号: N18092313
期刊: Applied Soil Ecology
作者: Guiping Ye, Yongxin Lin, Deyan Liu, Zengming Chen, Jiafa Luo, Nanthi Bolan, Jianbo Fan, Weixin Ding
更新时间: 2018-09-23
摘要: Addition of organic materials is believed to be a feasible practice for mitigating Ultisols acidification and loss of soil organic carbon (SOC). However, how organic materials mitigate acidification, affect SOC content and aggregation and shift microbial community structure requires further investigation. In this study, we used high-throughput sequencing of microbial DNA to evaluate the relationships between soil properties, aggregation and prokaryotic communities in soil subjected to 27 years of inorganic and organic fertilization. The field experiment included seven treatments: no fertilization (control), inorganic NPK fertilizer (I), inorganic NPK fertilizer plus liming (CaCO3) (IL), and inorganic NPK fertilizer plus peanut straw (IPS), rice straw (IRS), radish (IR), or pig manure (IPM). Amendment with NPK fertilizer plus pig manure more effectively increased soil pH, SOC, total nitrogen (TN), available phosphorus (AP) and dissolved organic carbon (DOC) compared with NPK fertilizer plus crop residues. IPM also increased the mass proportion of large macroaggregates (>2000 μm) from 7.8% in the control to 30.6% while it reduced effective diffusion coefficient of oxygen (DCo) from 12.58 × 10−6 m2 s−1 in the control to 2.81 × 10−6 m2 s−1. Application of pig manure increased prokaryotic diversity and altered prokaryotic community structure, while crop residues did not. Soil pH was the predominant factor influencing prokaryotic community structure. Bacillales and Clostridiales accounted for 47.5% and 21.4%, respectively of the indicator species in the IPM and the relative abundances of them were increased, compared with the other treatments. Furthermore, the relative abundances of Bacillales and Clostridiales were correlated with SOC, TN, AP and DOC, and negatively with DCo in the soil. Overall, our results suggest that application of NPK fertilizer plus pig manure rather than crop residues enhanced soil pH, improved SOC content and aggregation, increased prokaryotic diversity and altered community structure of prokaryote after 27-year fertilization.

14623. 题目: Changes of the organic carbon content and stability of soil aggregates affected by soil bacterial community after afforestation
文章编号: N18092312
期刊: CATENA
作者: F.Z. Zhao, X.D. Fan, C.J. Ren, L. Zhang, X.H. Han, G.H. Yang, J. Wang, R. Doughty
更新时间: 2018-09-23
摘要: Soil aggregation is one of the most important factors affecting soil organic carbon (SOC) stabilization, and the stability of aggregates depends in part on soil microbial diversity and composition. Interactions between the soil bacterial community and SOC content in soil aggregates after afforestation are poorly understood. In this study, we investigated difference in the diversity of soil bacterial with high-throughput 16S rRNA sequencing, as well as the SOC content in soil aggregates representing a chronosequence of 42, 27, and 17 years of Robinia pseudoacacia L. succession (RP42, RP27, and RP17), and in farmland (FL) soil for comparison (millet (Setaria italica) and soybean (Glycine max) rotation).The SOC content in RP17, RP27, and RP42 plots were significantly higher than that of FL by an average of 85.57%, 142.37%, and 76.69% in large macro-aggregates (>1 mm), small macro-aggregates (0.25–1 mm), and micro-aggregates (<0.25 mm), respectively. The Simpson index for the FL plot was significantly higher than that of the RP17, RP27, and RP42 plots, whereas the Shannon index followed the opposite trend. The dominant bacterial phyla detected were Proteobacteria, Acidobacteria, and Actinobacteria in each afforested and FL sites. These data revealed significant correlations between soil aggregate characteristics, such as SOC content, mean weight diameter (MWD), and geometric mean diameter (GMD), with the relative abundance of Proteobacteria, Actinobacteria, Acidobacteria, Chloroflexi, Gemmatimonadetes, Nitrospirae, Verrucomicrobia, and Planctomycetes. These relationships suggested that the effects of afforestation on SOC stabilization in soil aggregates are modulated by both soil aggregate size and also soil bacterial diversity. We demonstrate that the interaction between soil aggregate size and soil microbes might be a key factor in effective soil conservation, restoration, sustainability of agroecosystems, and erosion prevention.

14624. 题目: Alteration process during the post-agricultural restoration of Luvisols of the temperate broad-leaved forest in Russia
文章编号: N18092311
期刊: CATENA
作者: O. Kalinina, O. Chertov, P. Frolov, S. Goryachkin, P. Kuner, J. Küper, I. Kurganova, V. Lopes de Gerenyu, D. Lyuri, A. Rusakov, Y. Kuzyakov, L. Giani
更新时间: 2018-09-23
摘要: This chronosequential study focuses on the vegetation succession, Luvisol pedogenesis, and long-term carbon dynamics during post-agricultural restoration in the temperate broad-leaved forest of European Russia. The study comprises three chronosequences of 37 years (North), 120 years (Middle), and 42 years (South) to cover climatic differences within the study area. The sites of each catena were mostly comparable in terms of climate, soil texture, and land history, but the duration of agricultural abandonment differed between sites. Plant succession developed via a birch forest or a pear-ash woodland to a birch-oak forest with Aegopódium podagrária after 120 years, which indicates the plant association is near to a climax oak forest. Former homogenous plow horizons formed a new morphological stratification similar to natural Luvisols, due to the formation of a well rooted Ah horizon and an O horizon of mull; a change in soil structure from coarse blocky to granular; and decreasing bulk densities. However, plow features were identified even after 120 years of Luvisols restoration. During restoration, the former plow horizons showed minor changes of pH 5.4–5.6 (CaCl2). However, a slightly increased pH value within the newly developed Ah and O horizons induced a new pH stratification of the former plow horizon, approaching the natural soils. Compared to the former plow horizons below, soil organic carbon (SOC) and plant available nutrients (P, K) enrichment was observed within the newly developed Ah horizons. The SOC stocks of the 5 cm mineral topsoil increased from 0.8 to 1.7 kg m−2 (North), from 1.3 to 1.7 kg m−2 (Middle), and from 1.4 to 2.3 kg m−2 (South) during restoration. The surface organic layers showed SOC stocks of 0.1–0.2 kg m−2. However, the levels of the near-natural soils were not reached after 37 years (North) and 42 years (South) of restoration. The model predicted a recovery time of about 150 years to achieve a comparatively steady state. A negative effect of mowing was observed for the modelled SOC accumulation. Despite all these alterations, the study showed no full restoration for many parameters within the chronosequential timescale of 120 years.

14625. 题目: Algae granulation for nutrients uptake and algae harvesting during wastewater treatment
文章编号: N18092310
期刊: Chemosphere
作者: Wei Cai, Ziwen Zhao, Dawei Li, Zhongfang Lei, Zhenya Zhang, Duu-Jong Lee
更新时间: 2018-09-23
摘要: To overcome the high separation cost of microalgae, natural microalgae granulation was performed in open sequencing batch reactors (SBRs) by treating synthetic wastewater. After operation for 60 days, easily settled algae granules were obtained with an average size of 0.61 mm, sludge volume index (SVI) of 125 ml/g and settling velocity of 12.2 m/h. More extracellular polymeric substances (EPS) (∼252 mg/g-VSS) were detected to excrete with a higher proteins/polysaccharides (PN/PS) ratio (∼7) for the algae granules on day 60, which are beneficial for granulation. Meanwhile, the algae granules were found to have a higher phosphorus (P) content (33.4 mg-P/g-TSS) with higher P bioavailability (91.8%) when compared to the seed algae (20.4 mg-P/g-TSS). The obtained algae granules possess great potential for P recovery and reuse.
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14626. 题目: Designing biochar properties through the blending of biomass feedstock with metals: Impact on oxyanions adsorption behavior
文章编号: N18092309
期刊: Chemosphere
作者: Alba Dieguez-Alonso, Andrés Anca-Couce, Vladimír Frišták, Eduardo Moreno-Jiménez, Markus Bacher, Thomas Bucheli, Giulia Cimò, Pellegrino Conte, Nikolas Hagemann, Andreas Haller, Isabel Hilber, Olivier Husson, Claudia I. Kammann, Norbert Kienzl, Jens Leifeld, Thomas Rosenau, Gerhard Soja, Hans-Peter Schmidt
更新时间: 2018-09-23
摘要: Metal-blending of biomass prior to pyrolysis is investigated in this work as a tool to modify physico-chemical biochar properties and its behavior as adsorbent. Six different compounds were used for metal-blending: AlCl3, Cu(OH)2, FeSO4, KCl, MgCl2 and Mg(OH)2. Pyrolysis experiments were performed at 400 and 700 °C and the characterization of biochars properties included: elemental composition, thermal stability, surface area and pore size distribution, Zeta potential, redox potential, chemical structure (with nuclear magnetic resonance) and adsorption behavior of arsenate, phosphate and nitrate. Metal blending strongly affected biochars' surface charge and redox potential. Moreover, it increased biochars' microporosity (per mass of organic carbon). For most biochars, mesoporosity was also increased. The adsorption behavior was enhanced for all metal-blended biochars, although with significant differences across species: Mg(OH)2-blended biochar showed the highest phosphate adsorption capacity (250 mg g−1) while AlCl3-blended biochar showed the highest arsenate adsorption (14 mg g−1). Significant differences were present, even for the same biochar, with respect to the investigated oxyanions. This indicates that biochar properties need to be optimized for each application, but also that this optimization can be achieved with tools such as metal-blending. These results constitute a significant contribution towards the production of designer biochars.

14627. 题目: Comparative efficacy of organic and inorganic amendments for cadmium and lead immobilization in contaminated soil under rice-wheat cropping system
文章编号: N18092308
期刊: Chemosphere
作者: Yasir Hamid, Lin Tang, Muhammad Yaseen, Bilal Hussain, Afsheen Zehra, Muhammad Zahir Aziz, Zhen-li He, Xiaoe Yang
更新时间: 2018-09-23
摘要: Field experiments were conducted in two consecutive rice-wheat cropping seasons on a yellow clay soil to assess the efficacy of organic and inorganic amendments for cadmium (Cd) and lead (Pb) immobilization. Amendments were applied alone and in combinations to compare their efficacy for metals immobilization. Composite amendment of GSA-4 (Green Stabilizing Agent) and biochar resulted in higher biomass and grains yield for both rice (Oryza sativa L.) and wheat (Triticum aestivum L.). Liming, DEK1 (Di Kang No. 1) or GSA-4 amendment increased soil pH from 6.34 to 7.35, 7.20 and 7.15, respectively. Soil amendments significantly reduced DTPA extractable Cd and Pb in soil at wheat harvest. Cadmium and Pb fractionation showed a significant decrease in the extractable fractions by the amendment of biochar (34% and 25%) or GSA-4 (35% and 26%, respectively). GSA-4 and biochar amendment enhanced metals immobilization and reduced their uptake by plant and subsequent accumulation in the grains of rice and wheat, particularly with GSA-4. These results indicate that GSA-4 and biochar, especially their combination, have great potential for application to remediate Cd and Pb contaminated soils.
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14628. 题目: Adsorption mechanism of ZnO and CuO nanoparticles on two typical sludge EPS: Effect of nanoparticle diameter and fractional EPS polarity on binding
文章编号: N18092307
期刊: Chemosphere
作者: Liangliang Wei, Jing Ding, Mao Xue, Kena Qin, Sheng Wang, Ming Xin, Junqiu Jiang, Qingliang Zhao
更新时间: 2018-09-23
摘要: Worldwide application of nanotechnology has led to an increasingly release of nanoparticles in wastewater treatment systems, and thus into sewage sludge, which potentially impairs the disposal of sewage sludge. Here, the binding process, adsorption characteristics, and the contribution of fractional polarity of extracellular polymeric substances (EPS) of anaerobic granular sludge (AGS) and activated sludge (AS) to the nano-ZnO and nano-CuO adsorption were investigated. Briefly, CuO-NPs can be more efficiently adsorbed by the EPS-AGS than that of ZnO-NPs (1.31 ± 0.08 g/g VS vs 0.53 ± 0.04 g/g VS), and a smaller diameter of nanoparticles benefited the adsorption processes. Hydrophobic EPS (HPO-A and HPO-N) within these two sludge were more effective in removing nano-CuO and ZnO than were the hydrophilic fraction. For example, HPO-A and HPO-N obtained from AGS showed a relatively higher adsorption abilities (in g/g VS) of 2.09 ± 0.12 and 2.27 ± 0.14, respectively, for nano-CuO, much higher than HPI (0.76 ± 0.04 g/g VS). Structural variations of the EPS before and after nanoparticles sorption were evaluated via the analysis of infrared spectroscopy, which showed that the functional structures of hydroxyl, amino, carboxyl, amide groups and CeOeC groups played a major role in nanoparticles binding/removal. Sorption process of nano-CuO and nano-ZnO on unfractionated EPS well fitted by Langmuir isotherm, as well as a pseudo second-order kinetic model. However, adsorption process of HPO-A can be better simulated by Freundlich equation.
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14629. 题目: Ultraviolet/persulfate (UV/PS) pretreatment of typical natural organic matter (NOM): Variation of characteristics and control of membrane fouling
文章编号: N18092306
期刊: Chemosphere
作者: Zongping Wang, Ying Wan, Pengchao Xie, Aijiao Zhou, Jiaqi Ding, Jingwen Wang, Li Zhang, Songlin Wang, Tian C. Zhang
更新时间: 2018-09-23
摘要: The effects of ultraviolet/persulfate (UV/PS) pretreatment on ultrafiltration (UF) membrane fouling caused by typical natural organic matter (NOM) fractions including humic acid (HA), sodium alginate (SA), and bovine serum albumin (BSA) were investigated. UF membrane fouling during the filtration of different NOM fractions after UV/PS pretreatment was compared through the evaluation of normalized membrane flux decline and membrane fouling reversibility. The fouling mitigation mechanisms were investigated through the characterization of ultraviolet absorbance (UV254), dissolved organic matter, zeta potential, particle size distribution, fluorescence excitation-emission matrix spectra, and fitness of four classic fouling models. Furthermore, the fouled membranes were characterized by Fourier-transform infrared spectroscopy and scanning electron microscopy. The results showed that UV/PS pretreatment significantly alleviated membrane fouling caused by HA, SA, and HA-SA-BSA mixture, and the fouling control performance improved at high PS doses. However, either UV alone or UV/PS pretreatment at low PS dose (10 mg/L) significantly aggravated BSA fouling with the normalized flux at the end of first filtration cycle being 8% and 15%, respectively. The increased particle size of BSA after UV/PS pretreatment was attributed to the formation of aggregates, which mainly accumulated in membrane pores and aggravated membrane fouling. Modeling results suggest that the mitigation of membrane fouling derived from SA and mixed organic fractions was primarily ascribed to the control of cake filtration, while the mitigation of HA fouling was attributed to the declined contribution of standard blocking.
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14630. 题目: Monitoring WWTP performance using size-exclusion chromatography with simultaneous UV and fluorescence detection to track recalcitrant wastewater fractions
文章编号: N18092305
期刊: Chemosphere
作者: Alexey Ignatev, Tuula Tuhkanen
更新时间: 2018-09-23
摘要: A trial monitoring of a typical full-scale municipal WWTP in Central Finland was aimed to explore applicability of high performance liquid chromatography – size exclusion chromatography (HPSEC) with simultaneous UV and fluorescence detection as a tool for advanced routine monitoring of wastewater treatment. High, intermediate, and low molecular weight (MW) fractions of wastewater influent and secondary effluent were characterized in terms of UV absorbance at 254 nm (UVA254) and specific fluorescence represented tyrosine-like, tryptophan-like, and humic/fulvic-like compounds.The activated sludge treatment removed 97 ± 1% of BOD, 93 ± 2% of COD, 71 ± 7% of DOC, and 24 ± 7% of TN, while reduction of total UVA254 was 50 ± 6%. Intensity of total fluorescence signal declined by ∼80% for tyrosine-like, by 60–70% for tryptophan-like, and by 7–36% for humic/fulvic-like compounds. Low and intermediate MW humic/fulvic-like compounds fluorescing at λex/λem = 390/500 nm demonstrated recalcitrant behavior. Protein-like and humic/fulvic-like fractions of low MW < 1 kDa accounted for 60–65% of total UVA254 and 50–70% of total fluorescence of whole influent and effluent samples. Strong linear correlations were observed between BOD, COD, DOC, UVA254 and tyrosine-like, tryptophan-like fluorescence.The analytical approach based on HPSEC with simultaneous UV and fluorescence detection allows rapid and advanced characterization of natural and anthropogenic organic matter in water treatment and distribution systems. Fairly good resolution archived in the HPSEC separation offers new opportunities for fingerprinting and tracking specific wastewater fractions.
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14631. 题目: Seabird colonies as relevant sources of pollutants in Antarctic ecosystems: Part 2 - Persistent Organic Pollutants
文章编号: N18092304
期刊: Chemosphere
作者: C.V.Z. Cipro, P. Bustamante, S. Taniguchi, J. Silva, M.V. Petry, R.C. Montone
更新时间: 2018-09-23
摘要: Despite typically not being taken into account (usually in favour of the ‘global distillation’ process), the input of persistent organic pollutants (POPs) through biological activities can be indeed relevant at the local scale in terrestrial polar environments when seabird colonies are considered. Seabirds can bioaccumulate and biomagnify POPs, gather in large numbers and excrete on land during their reproductive season, thus making them locally as relevant secondary sources of the POPs. The first part of this study indicated that these colonies act as so for several essential and non-essential trace elements, and this second part tests the same hypothesis concerning POPs using the very same samples. Lichens (n = 55), mosses (n = 58) and soil (n = 37) were collected from 13 locations in the South Shetlands Archipelago during the austral summers of 2013–14 and 2014–15. They were divided in colony (within the colony itself for soil and within and surrounding the colony for vegetation) and control (at least 150 m away from any colony interference) and analysed for POPs such as organochlorine pesticides, polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers and stable isotopes (C and N). Results showed that colonies act clearly as a secondary source for PCBs and likely for hexachlorobenzene. As in the first part, probable local sources other than the colonies themselves are hypothesised because of high concentrations found in control sites. Again, soil seemed the most adequate matrix for the intended purposes especially because of some particularities in the absorption of animal-derived organic matter by vegetation, pointed out by stable isotope analyses.

14632. 题目: Algal uptake of hydrophilic and hydrophobic dissolved organic nitrogen in the eutrophic lakes
文章编号: N18092303
期刊: Chemosphere
作者: Weiying Feng, Shasha Liu, Cuicui Li, Xiaofeng Li, Fanhao Song, Beibei Wang, Haiyan Chen, Fengchang Wu
更新时间: 2018-09-23
摘要: Dissolved organic nitrogen (DON) derived from sediments plays an active role in biogeochemical cycling of nutrients in aquatic ecosystems. Sediments from four eutrophic lakes were studied using three-dimensional fluorescence excitation-emission matrix (3DEEM) spectra and supelite XAD-8 macroporous resin separation to investigate the bioavailability of hydrophilic and hydrophobic DON to algae (Microcystis flos-aquae (Wittr.) Kirchner). The results showed that the average loss of DON was <6.0% after dividing DON into hydrophilic and hydrophobic components, demonstrating the utility of XAD-8 resin separation in the study of DON components from lake sediments. The 3DEEM analysis showed that hydrophobic and hydrophilic DON comprised humic- and protein-like materials, respectively. During the incubation period, the bioavailability of hydrophilic DON, which accounted for 59.3%–80.4% of total DON, stimulated algal growth, suggesting that hydrophilic DON was the primary source of organic nitrogen for algae. In contrast, hydrophobic DON increased algal density by only 31.8% of that observed for hydrophilic DON, and had a small (accounted for 20.0%–26.6% of total DON) effect on algal growth over the short-term. The significant differences in algal growth between the two types of DON suggested that they should be considered separately in the eutrophic lake restorations.
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14633. 题目: N-propyl functionalized spherical mesoporous silica as a rapid and efficient adsorbent for steroid estrogen removal: Adsorption behavior and effects of water chemistry
文章编号: N18092302
期刊: Chemosphere
作者: Pei Gao, Chun Yang, Zhijie Liang, Wenhao Wang, Zhiwei Zhao, Bibo Hu, Fuyi Cui
更新时间: 2018-09-23
摘要: To achieve an enhanced and selective adsorption of steroid estrogens, the n-propyl functionalization was applied to the mesoporous silica material (MCM-41) according to the physico-chemical properties analysis of steroid estrogens. Adsorption behavior and water chemistry effects were evaluated with the most concerned steroid estrogens: estrone (E1), 17β-estradiol (E2) and 17α-ethinyl estradiol (EE2) based on the materials characterization. The results showed the uptakes of E1, E2, and EE2 onto the modified MCM-41 were enhanced and accelerated by the n-propyl functionalization, which was positively correlated with the hydrophobicity of the synthesized materials. Kinetic data fitted the pseudo-second-order model well. Based on the Langmuir model, the maximum adsorption capacities of the n-propyl modified MCM-41 were up to 119.87, 88.38, and 86.91 mg g−1 for EE2, E1, and E2, respectively. Importantly, both acid and neutral solutions were beneficial to estrogen removal, but ionic strength and humic acid did not affect the estrogen adsorption. The above results suggested that the n-propyl functionalized MCM-41 would be a promising adsorbent for the rapid and efficient removal of estrogens with the selectivity from natural organic matter like humic acid. Mechanism analysis showed the key role of hydrophobic interaction, and it also confirmed the contribution of the carbonylic lone pair electrons of E1, which helped the formation of stronger hydrogen bonds with silicon hydroxyls and enhanced the dipole-dipole interaction between E1 and the synthesized materials.
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14634. 题目: Preparation and properties of Cu-Ni bimetallic oxide catalyst supported on activated carbon for microwave assisted catalytic wet hydrogen peroxide oxidation for biologically pretreated coal chemical industry wastewater treatment
文章编号: N18092301
期刊: Chemosphere
作者: Zhipeng Li, Feng Liu, Yi Ding, Fei Wang, Hong You, Chao Jin
更新时间: 2018-09-23
摘要: A microwave (MW)-assisted catalytic wet hydrogen peroxide oxidation (CWHPO) process was investigated to treat biologically pretreated coal chemical industry wastewater (CCIW) in this study. The activated carbon (AC) supported Cu-Ni bimetallic oxide catalyst was prepared by impregnation and precipitation method for MWCWHPO. The catalytic performance of the catalyst was investigated, and the main influencing factors were discussed. The results showed that the removal efficiencies of quinoline and total organic carbon (TOC) with catalyst prepared by impregnation method were 85% and 70%, respectively, and the removal efficiencies of quinoline and TOC with catalyst prepared by precipitation method were up to 95% and 76%, respectively. The utilization rate of hydrogen peroxide (H2O2) and the generation quantity of hydroxyl radicals were higher in the reaction process with the catalyst prepared by precipitation method than those with the catalyst prepared by impregnation method. The characterization of the catalyst showed that the smaller active component grains size, larger surface area and higher proportion of chemical adsorption oxygen were the main reason for the high catalytic efficiency. Furthermore, the optimized reaction conditions were: reaction temperature of 60 °C, microwave power of 500 W, and H2O2 initial concentration of 0.066 M. Moreover, the Cu-Ni bimetallic oxide catalyst is an efficient and stable catalyst in the degradation and mineralization of pollutants in the MWCWHPO process. The synthesized catalyst was verified to be attractive for use in the heterogeneous wet peroxide oxidation system under microwave irradiation.
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14635. 题目: Copper Mobilization and Immobilization along an Organic Matter and Redox Gradient—Insights from a Mofette Site
文章编号: N18092218
期刊: Environmental Science & Technology
作者: Judith Mehlhorn, Johannes Besold, Juan S. Lezama Pacheco, Jon Petter Gustafsson, Ruben Kretzschmar, Britta Planer-Friedrich
更新时间: 2018-09-22
摘要: Mofettes (natural geogenic CO2 exhalations) represent excellent sites to study the behavior of Cu in soils and the co-occurrence of different mobilization and immobilization processes since they exhibit both a gradient in redox conditions (oxic to permanently anoxic) and in soil organic matter (SOM; low to high contents). Soil and pore water samples from an 18 m-transect over a mofette showed a complex behavior of Cu, with highest mobility in the transition between oxic and anoxic conditions. Cu(II) sorption experiments on SOM-rich topsoil revealed that Cu mobility under oxic conditions was confined by adsorption to SOM while in the oxygen-free mofette center reduction and precipitation of sulfides was the dominating Cu-sequestering process. In transition areas with low amounts of oxygen (<10%), there was no mineral precipitation, instead high dissolved-to-soil organic carbon ratios strongly increased Cu mobility. Our results show that low stability of SOM formed under oxygen-limited conditions leads to increased Cu mobility unless sulfur-reducing conditions cause Cu sequestration by sulfide precipitation. The interplay of these (im)mobilization processes and especially the unexpectedly high mobility under suboxic conditions have to be considered when assessing Cu mobility along spatial or temporal redox gradients, e.g., at contamination sites or periodically flooded soils.
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14636. 题目: Surface sediment properties and heavy metal contamination assessment in river sediments of the Pearl River Delta, China
文章编号: N18092217
期刊: Marine Pollution Bulletin
作者: Guangming Zhao, Siyuan Ye, Hongming Yuan, Xigui Ding, Jin Wang, Edward A. Laws
更新时间: 2018-09-22
摘要: Concentrations of arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), lead (Pb), and zinc (Zn), grain sizes, and concentrations of organic carbon (Corg) were measured in 323 river sediment samples from the Pearl River Delta (PRD). Results showed that the heavy metal concentrations in the sediments ranged from 1.6–93 mg/kg for As, 0.04–9.3 mg/kg for Cd, 2–315 mg/kg for Cr, 1.1–352 mg/kg for Cu, 0.01–0.67 mg/kg for Hg, 11–221 mg/kg for Pb, and 11–1234 mg/kg for Zn. The highest values of As, Cr, Cu, Hg, Pb, and Zn appeared in the Beijiang River, whereas Cd was high in the Xijiang River. The overall sediment quality in the area with respect to metal concentrations generally met the primary standard criteria of China (Marine Sediment Quality), except for Cd and Cu. The spatial distributions of the heavy metals were influenced by both grain sizes and Corg concentrations. The Igeo geo-accumulation index indicated that there was no significant Cr, Cu, Hg, or Zn pollution, slight to moderate pollution by As and Pb, and moderate Cd pollution in the study area. Spatial distributions of an eco-toxicological index based on probable effect levels indicated that there was a 21% probability that the combination of the seven metals was exerting a toxic stress in the PRD river sediments.

14637. 题目: Organic matter removal associated with forest harvest leads to decade scale alterations in soil fungal communities and functional guilds
文章编号: N18092216
期刊: Soil Biology and Biochemistry
作者: Ryan M. Mushinski, Terry J. Gentry, Thomas W. Boutton
更新时间: 2018-09-22
摘要: Intensive organic matter removal (OMR) associated with timber harvest has the potential to impart long-term alterations to soil biota and associated properties and processes; however, there is a lack of data to say if this trend persists at depth. This study investigated how OMR influences long-term stability of soil fungi to a depth of 1 meter using a replicated experimental pine forest in the Gulf Coastal Plain, USA. Treatments included unharvested control stands as well as low- and high-OMR stands. Intensive OMR led to significant differences in community structure and the abundance of functional guilds in surficial soil. Saprophytic taxa increased while ectomycorrhizal (ECM) taxa decreased with intensive-OMR, which correlated strongly with increased surface temperature and reduced soil nitrogen. Ericoid mycorrhizae (ERM) also increased in intensive-OMR stands, which may indicate that following disturbance, ERM could outcompete ECM for colonization of subsequent seedlings. Overall, no differences were observed below 30 cm, except for alpha diversity, which was a function of high inter-replicate variability. Our results illustrate a distinct long-term structural and functional response of soil fungi to intensive-OMR in the upper portions of the soil profile, which could lead to altered stand productivity and ecosystem services.

14638. 题目: Utilization of fly ash as pH adjustment for efficient immobilization and reutilization of nutrients from swine manure using hydrothermal treatment
文章编号: N18092215
期刊: Waste Management
作者: Wen Fan, Michelle Srisupan, Lucas Bryant, Jason P. Trembly
更新时间: 2018-09-22
摘要: Hydrothermal treatment has been proven an effective process for immobilization of phosphorus and other macronutrients from animal wastes. Recent research has shown biochars generated from hydrothermal treatment are relatively low in phosphorus availability to be used as a fast release fertilizer substitute. In this research, basic (>7 pH) environment was evaluated at 250–400 °C to determine its impacts on nutrient immobilization and mobility from solid products generated from swine manure. Both fly ash and 0.1 M NaOH were used to adjust hydrothermal treatment environment pH and compared with DI water. Macronutrients were found to be more efficiently immobilized in the basic environments, particularly with addition of fly ash. Further, fly ash altered crystal phases formed at the treatment temperatures resulting in differences of biochar nutrient mobility. Further, post-treatment products were evaluated for heavy metal release for potential use in agricultural applications.

14639. 题目: Sequential white-rot and brown-rot fungal pretreatment of wheat straw as a promising alternative for complementary mild treatments
文章编号: N18092214
期刊: Waste Management
作者: Edward Hermosilla, Olga Rubilar, Heidi Schalchli, Ayla Sant'Ana da Silva, Viridiana Ferreira-Leitao, María Cristina Diez
更新时间: 2018-09-22
摘要: White-rot and brown-rot fungi have complementary mechanisms to selectively degrade lignin and holocellullose, respectively. Thereby, a fungal co-culture of a white-rot and a brown-rot fungal could result in efficient strategy for a mild lignocellulosic biomass pretreatment. In this work, single, sequential and co-inoculation of the selective-lignin degrading white-rot fungus Ganoderma lobatum and the brown-rot fungus Gloeophyllum trabeum were evaluated as biological pretreatments of wheat straw to enhance enzymatic hydrolysis of cellulose. The single cultures of G. lobatum and G. trabeum exhibited preferential degradation of lignin and hemicellulose, respectively. The total crystallinity index decreased in samples pretreated with G. trabeum but not with G. lobatum. The pretreatment with single cultures of G. lobatum or G. trabeum increased glucose yields by 43.6% and 26.1% respectively compared to untreated straw. Although co-inoculation resulted in higher yields of glucose when compared with single cultures, only a slight synergistic effect between fungi was observed. Contrary, the sequential inoculation of G. lobatum incubated for 10 days followed by G. trabeum incubated for 10 days more showed a strong synergic effect on enzymatic hydrolysis. This sequential culture showed the highest glucose yield (191.5 mg g−1 wheat straw), 2.8-fold higher than untreated wheat straw, and 140–150% higher than the single-cultures of G. lobatum and G. trabeum, respectively.

14640. 题目: Production, characterization and adsorption studies of bamboo-based biochar/montmorillonite composite for nitrate removal
文章编号: N18092213
期刊: Waste Management
作者: Eva Viglašová, Michal Galamboš, Zuzana Danková, Lukáš Krivosudský, Christian L. Lengauer, Rebecca Hood-Nowotny, Gerhard Soja, Annette Rompel, Marek Matík, Jaroslav Briančin
更新时间: 2018-09-22
摘要: Biochar is a promising immobilization tool for various contaminants in liquid wastes, aqueous solutions and soils. To further improve the sorption characteristics, a biochar/montmorillonite composite was produced and synthesized in an experimental pyrolysis reactor, using bamboo as biomass feedstock. The composite was characterized by physico-chemical and structural methods (FTIR, SEM, SEM/EDX, SSA, Low temperature nitrogen adsorption method). Based on these methods, the successful preparation of a bamboo based biochar/montmorillonite composite preparation has been demonstrated. The particles of montmorillonite were distributed across the biochar surface. The adsorption studies for removal nitrates from aqueous solutions were investigated by a batch method at laboratory temperatures. The experimental data were fitted by three adsorption models (Langmuir, Freundlich and DR; R2 > 0.93). The maximum adsorption capacity achieved by biochar at pH 4, was about 5 mg g−1 and by biochar/montmorillonite composite 9 mg g−1. The results suggest that the bamboo-based biochar/montmorillonite composite can be used effectively in the treatment of industrial effluents or waste water containing anionic pollutants such as nitrates.
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