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961.
962.
To explore the sediment interception capacity of plants and its relationship with the surface morphological traits of plants, we used laboratory simulations and off-site flume experiments to study the ability for sediment retention of six familiar species: Leucaena leucocephala (LL), Melia azedarach (MA), Dodonaea viscosa (DV), Coriaria sinica (CS), Heteropogon contortus (HC), and Eulaliopsis binata (EB) aver two growth periods in the dry-hot river valley of the Jinsha River. We analyzed the relationship between near-surface morphological traits of individuals of six species and their ability for sediment retention. Our study resulted in three main observations. (1) In the flume experiment, three-month seedlings and one-year old seedlings of the six species showed different abilities for sediment retention. In the three-month seedlings, the ability for sediment retention of CS was the highest, followed by MA and LL, whereas it was the lowest in HC and EB. However, in one-year old seedlings, the ability for sediment retention of CS was the highest, but the ability for sediment retention of HC and EB was better than those of MA and LL. Hence, the ability for sediment retention of the six species fluctuated between different growth periods. (2) The three-month old and one-year old seedlings of all six species showed different near-surface morphological traits. (3) The sediment mass was significantly and positively correlated with near-surface leaf areas, crown lengths, crown widths, stem dry matter densities at the intersection volume, and above-ground biomass, but significantly and negatively correlated with the angle between stem and ground, indicating that these latter are the main near-surface morphological traits able to affect sediment retention. In addition, the sediment mass was also correlated (positively and negatively) with the stem epidermal crack number, stem dry matter content, leaf dry matter content at the intersection volume, and dry mass per unit volume of the intersection volume, which could also reflect the ability of sediment retention. We conclude that in the areas where plant measures are used to control soil erosion and intercept sediment, the key, above-mentioned plant morphological factors should be taken into account in order to select the optimal plant species. © 2018 Science Press. All rights reserved. 相似文献
963.
Caiting Li Qun Li Pei Lu Huafei Cui Guangming Zeng 《Frontiers of Environmental Science & Engineering》2012,6(2):156-161
A series of CeO2 supported V2O5 catalysts with various loadings were prepared with different calcination temperatures by the incipient impregnation. The catalysts were evaluated for low temperature selective catalytic reduction (SCR) of NO with ammonia (NH3). The effects of O2 and SO2 on catalytic activity were also studied. The catalysts were characterized by specific surface areas (SBET) and X-ray diffraction (XRD) methods. The experimental results showed that NO conversion changed significantly with the different V2O5 loading and calcination temperature. With the V2O5 loading increasing from 0 to 10 wt%, NO conversion increased significantly, but decreased at higher loading. The optimum calcination temperature was 400°C. The best catalyst yielded above 80% NO conversion in the reaction temperature range of 160°C–300°C. The formation of CeVO4 on the surface of catalysts caused the decrease of redox ability. 相似文献
964.
沼液培养的普通小球藻对CO2的去除 总被引:4,自引:0,他引:4
利用微藻固定CO2和处理污水已成为微藻应用的一个重要研究方向.利用营养丰富的沼气发酵废液培养小球藻,藻种经驯化后在不同浓度沼液中能良好生长.小球藻在高浓度的CO2中有较好的生长和较强的耐受能力,在1.5%CO2通气下生物量最高.在此基础上考察了沼液中小球藻对CO2的去除情况.结果表明,提高小球藻生长速率和CO2浓度可以增加小球藻对CO2的去除量,降低通气也可提高CO2去除率.在1.5%CO2浓度、通气量60 mL min-1条件下,CO2去除率可达30.61%;在10%CO2浓度、通气量100 mL min-1时最高去除量为279.7 mg L-1 h-1.采用六管串联通气培养小球藻去除粗沼气中的CO2,去除量为(205.80±13.20)mg L-1 h-1,去除率为60.32%±3.73%.在同样的通气量下,CO2的去除量与单管培养相近,去除率是单管培养的近6倍,因此小球藻对沼气中的CO2具有良好的去除效果.图4表2参17 相似文献
965.
Since the 1992 Rio Earth Summit, sustainable development has been embraced as an important goal. In order to measure sustainable development, many scientists and researchers have made efforts to establish measurement systems such as the Driving Force State Response (DSR) framework (Hens 1995), the Human Development Index (HDI) (Goeteyn 1996) devised by the United Nations Development Programme, the Sustainable National Income (SNI) developed by Hueting et al. (1992) and the Ecological Footprint proposed by Wackernagel and Rees (1996). The environmental sustainability index (ESI) is a composite index, which was created by the World Economic Forum, Yale and Columbia Universities, aggregating data at the national level to measure a country's performance in sustaining a healthy, livable environment. 142 countries have been measured with ESI by 2002. However, it has not yet been documented if it can be applied at a regional level. In this study, we have tried to apply ESI to measure the sustainable development of Shandong in China. 22 indicators and 43 variables were chosen, and results showed the ESI of Shandong was 49, suggesting that Shandong is still far from a position of sustainable development. 相似文献
966.
Antonio Jose Capezza Yuxiao Cui Keiji Numata Malin Lundman William Roy Newson Richard Tobias Olsson Eva Johansson Mikael Stefan Hedenqvist 《Advanced Sustainable Systems》2020,4(9)
Synthesis of superabsorbent particles from nontoxic wheat gluten (WG) protein, as an industrial co‐product, is presented. A natural molecular cross‐linker named genipin (a hydrogenated glycoside) is used together with a dianhydride (ethylenediaminetetraacetic EDTAD), to enable the preparation of a material with a network structure capable of swelling up to ≈4000% in water and ≈600% in saline solution. This represents an increase in swelling by over 10 times compared to the already highly absorbing gluten reference material. The carboxylation (using EDTAD) and the cross‐linking of the protein result in a hydrogel with liquid retention capacity as high as 80% of the absorbed water remaining in the WG network on extensive centrifugation, which is higher than that of commercial fossil‐based superabsorbents. The results also show that more polar forms of the reacted genipin are more effectively grafted onto the protein, contributing to the swelling and liquid retention. Microscopy of the materials reveals extensive nanoporosity (300 nm), contributing to rapid capillarity‐driven absorption. The use of proteins from agricultural industries for the fabrication of sustainable protein superabsorbents is herein described as an emerging avenue for the development of the next generation daily‐care products with a minimal environmental impact. 相似文献
967.
为了研究土壤中铜的生物可给性与土壤理化性质之间的相互关系以及人体无意摄入土壤铜的风险,采集我国一些地区的15个土壤样品,利用in vitro方法研究了这些土壤中铜的生物可给性及其对人体的健康风险。结果表明,有2个土壤样品中铜的含量高过我国土壤环境质量标准的三级标准,有8个土壤样品中铜的含量高过二级标准;土壤中铜的溶解态浓度及其生物可给性变化很大,胃肠阶段铜的溶解态含量分别为5.2~308.8 mg·kg~(-1)和5.9~348.5 mg·kg~(-1),平均值分别为74.8 mg·kg~(-1)和82.0 mg·kg~(-1);而铜的生物可给性分别为183%~66.6%和213%~77.4%,平均值分别为442%和51.1%。胃阶段铜的生物可给性与土壤有机质和pH呈显著正相关,而与粘粒呈显著负相关,与铁铝氧化物有显著相关性;小肠阶段铜的生物可给性与土壤有机质和pH呈显著正相关,与土壤中总铜和锰氧化物含量呈显著负相关。如以胃阶段为判断,无意摄人土壤中铜对儿童的TDI(tolerable daily intake)贡献率除浙江富阳为2.51%外,有12个土壤样品低于1.00%,最低为0.11%。如以小肠阶段为判断,无意摄入土壤中铜对儿童的TDI贡献率除浙江富阳和浙江台州的土壤分别为2.83%和2.01%,另有12个土壤样品低于1.00%。可见,对于本研究中大多数土壤,通过口部无意摄入土壤中铜的对人体并没有很高的风险。 相似文献
968.
Junlian QIAO Zimin CUI Yuankui SUN Qinghai HU Xiaohong GUAN 《Frontiers of Environmental Science & Engineering》2014,8(2):169-179
A1-Fe (hydr)oxides with different A1/Fe molar ratios (4:1, 1:1, 1:4, 0:1) were prepared using a co- precipitation method and were then employed for simultaneous removal of arsenate and fluoride. The 4A1 : Fe was superior to other adsorbents for removal of arsenate and fluoride in the pH range of 5.0-9.0. The adsorption capacity of the A1-Fe (hydr)oxides for arsenate and fluoride at pH 6.50.3 increased with increasing A1 content in the adsorbents. The linear relationship between the amount of OH released from the adsorbent and the amount of arsenate or fluoride adsorbent by 4A1 : Fe indicated that the adsorption of arsenate and fluoride by A1- Fe (hydr)oxides was realized primarily through quantita- tive ligand exchange. Moreover, there was a very good correlation between the surface hydroxyl group densities of A1-Fe (hydr)oxides and their adsorption capacities for arsenate or fluoride. The highest adsorption capacity for arsenate and fluoride by 4A1 : Fe is mainly ascribed to its highest surface hydroxyl group density besides its largest pHpzc. The dosage of adsorbent necessary to remove arsenate and fluoride to meet the drinking water standard was mainly determined by the presence of fluoride since fluoride was generally present in groundwater at much higher concentration than arsenate. 相似文献
969.
Di CUI Ang LI Tian QIU Rui CAI Changlong PANG Jihua WANG Jixian YANG Fang MA Nanqi REN 《Frontiers of Environmental Science & Engineering》2014,8(6):937-944
Bioaugmentation is an effective method of treating municipal wastewater with high ammonia concentration in sequencing batch reactors (SBRs) at low temperature (10℃). The cold-adapted ammonia- and nitrite- oxidizing bacteria were enriched and inoculated, respectively, in the bioaugmentation systems. In synthetic wastewater treatment systems, the average NH4+-N removal efficiency in the bioaugmented system (85%) was much higher than that in the unbioaugmented system. The effluent NH4+ -N concentration of the bioaugmented system was stably below 8 mg. L1 after 20 d operation. In municipal wastewater systems with bioaugmentation, the effluent NH4+- -N concentration was below 8 mg·L^-1 after 15 d operation. The average NH4+ -N removal efficiency in unbioaugmentation system (about 82%) was lower compared with that in the bioaugmentation system. By inoculating the cold-adapted nitrite-oxidizing bacteria (NOB) into the SBRs after 10 d operation, the nitrite concentration decreased rapidly, reducing the NO2 -N accumulation effectively at low temperature. The func- tional microorganisms were identified by PCR-DGGE, including uncultured Dechloromonas sp., uncultured Nitrospira sp., Clostridium sp. and uncultured Thauera sp. The results suggested that the cold-adapted microbial agent of ammonia-oxidizing bacteria (AOB) and NOB could accelerate the start-up and promote achieving the stable operation of the low-temperature SBRs for nitrification. 相似文献
970.
昆虫病毒的发现始于16世纪,但直到本世纪50年代,伴随着电子显微镜的发明,昆虫病毒学的研究才得到飞速发展.近年来,昆虫病毒学的研究已引起人们的高度重视,主要是因为:1.杆状病毒可做为载体,以表达外源基因;2.做为杀虫剂,可有效地控制农业病虫害的发生,... 相似文献