控制Na^＋转运以及维持Na^＋／K^＋平衡有助于提高植物的耐盐性

盐害（包括土壤次生盐渍化）造成的日益严重的环境问题已在世界范围内引起了广泛关注。大量针对植物耐盐分子机制的研究已开展,旨在更好地了解植物自身的耐盐机制。到目前为止,已获取了大量关于植物耐盐性机制的信息。同时,人们正在形成一个共识,即植物维持自身细胞离子平衡的能力是其具有耐盐性的关键。Na^＋／H^＋、K^＋／H^＋和Na^＋／K^＋逆向转运蛋白及其同源蛋自在植物细胞维持离子平衡中的关键作用受到了人们越来越多的关注。结合前人的研究结果和最新的研究动态,着重阐述了Na^＋转运控制和维持细胞离子平衡在植物耐盐过程中的机理及其重要作用。     

植物对Cd~(2+)胁迫的调控机理研究进展

重金属Cd作为非必需微量元素,经根系吸收并累积时对植物具有很强的毒性,因而开展植物对Cd的响应途径及其调控机理研究,对改良植物对Cd的耐受性以及开发超累积植物均具有重要意义。植物硫代谢、抗氧化系统和Cd2+跨膜运输是植物对重金属镉响应的主要途径,以上3种耐受机制的研究进展包括Cd2+诱导植物硫转运蛋白、硫还原相关酶类以及半胱氨酸、谷胱甘肽和植物螯合肽合成及其基因表达调控,Cd2+诱发的植物抗氧化反应及其基因表达,质膜和液泡转运蛋白促进Cd2+运输和隔离的基因调控。     

应用多思单元的离子色谱法测定降水中六种阳离子

笔者通过研究建立了应用单标多点校正和英蓝超滤单元的非抑制电导离子色谱法测定降水中Li+、Na+、NH4+-N、K+、Ca2+、Mg2+6种阳离子的方法。该方法操作简单,样品无需过滤即可上机分析测定;检出限低,范围在0.005～0.04 mg/L;重复测定相对标准偏差小于5%,加标回收率稳定在96.7%～104.6%;线性范围广,待测离子之间无明显干扰,可同时快速测定降水中不同浓度的阳离子。同时该方法降低了标准品配制和样品前处理的复杂性。     

高盐废水人工湿地处理中耐盐植物的筛选

天津塘沽作为滨海新区核心区,是目前天津发展最快的地区之一。由于本区盐碱土壤等自然条件,污水中盐分含量较高,制约了废水的回用。本文通过模拟人工湿地实验,比较了芦苇（Phragmites australis）、盐地碱篷（Suaeda salsa）、碱蒿（Artemisia anethifo原lia）、黄花鸢尾（Iris wilsonii）、盐角草（Salicornia europaea）和大米草（Spartina anglica）等耐盐植物对轻污染水体中高浓度氯离子的去除能力,筛选出去除能力较强的植物,并确定植物对盐分去除率达到最大时的生态系统条件。结果表明,适合人工湿地的耐盐碱植物对氯离子的去除效果依次为：芦苇＆gt;盐地碱篷＆gt;碱蒿＆gt;黄花鸢尾＆gt;盐角草＆gt;大米草,停留时间一般在第4d时可达到平衡。该研究为利用人工湿地处理高盐废水提供了科学依据。     

盐度渐变过程对黄条鰤(Seriola aureovittata)幼鱼渗透调节的影响

为了解盐度渐变对黄条鰤(Seriola aureovittata)渗透调节的影响,设置自然海水(对照组盐度为29),5,10,15,20,35六个盐度梯度,并对不同盐度下幼鱼鳃丝Na+/K+-ATP 酶活力、离子浓度、渗透压进行了检测和分析。结果显示:在盐度5~35,黄条鰤尿、血清、血浆的渗透压均随盐度升高而升高,盐度为35时渗透压均为最高,其中尿的渗透压显著高于血清和血浆渗透压。在盐度从29下降的过程中,鳃丝Na+/K+-ATP酶活力、离子浓度、渗透压呈现相似的变化规律,都随着盐度的降低而呈现总体下降的趋势;盐度从29升高到35时,各检测指标中仅有尿和血浆的K+ 含量无显著变化(P >0.05),其余均显著升高(P <0.05)。实验结果表明,黄条鰤生存和繁衍的自然海水盐度29是幼鱼存活的适宜盐度,在略低的盐度20~29均能较快适应,说明在盐度渐变过程中,黄条鰤幼鱼对外界盐度变化有较强的调节能力。     

“互联网+电商”背景下基于多功能开放型供需网的街区适宜尺度研究CSSCI

封闭式小区制约着我国经济结构的重要调整,影响着我国供给侧改革的实施进程。在"互联网+电商"背景下,针对现有封闭小区增加电商物流成本,不能适应新经济的发展这一现状和开放式小区街区适宜尺度的测度问题,结合实际生活,借鉴供需网的相关知识,对街区和街区尺度内涵进行了界定,对街区尺度的演化动力机制进行了探讨,构建了基于供需网的街区适宜尺度判定要素模型。以上海市杨浦区5个小区为例,对其进行了实证研究,验证了上述模型的可行性。研究发现:在"互联网+电商"背景下,基于多功能开放型供需网的街区适宜尺度模型可有效测度街区尺度,为街区开放的判定提供一定的依据。基于上述研究,针对新建开放式小区和已有封闭小区的逐步打开方式应注意的问题提出了建议。     

粒粒泡果汁饮料加工工艺

冬泡（RubusLambertianusSer．）为蔷薇科悬钩子属植物，在我国分布较广，河南省主要分布于大别山、伏牛山、桐柏山区，资源蕴藏量丰富。民间常来各泡野果食用，果实桔红鲜亮、甜酸爽口、酸感较强。冬泡含有大量糖类、有机酸、蛋白质、VC和较丰富的SOD，具有一定的营养保健作用。随着生活水平的提高，人们越来越崇尚天然绿色食品，因此，开发利用野生资源已成为人们关注的焦点。悬钩子是重要的野生果树资源，不少学者在其引种、驯化和营养分析等方面已进行了一些研究[1，2]。本文在对河南省悬约于属植物资源调查的基础上，利用冬泡果实…     

Fe-P双掺杂二氧化钛复合材料的制备及其对铊的吸附研究

以钛酸四丁酯为原料，利用水解法构造了Ti-O-Ti的空间结构，通过添加有机硝酸铁和磷酸氢二铵两种原料，向其空腔内引入Fe、P双元素掺杂，得到P-FeN-TiO₂复合材料。使用扫描电镜(SEM)观察了材料的表面形貌，通过吸附等温线、吸附动力学拟合模型分析材料对铊的吸附性能；考察不同溶液pH值、阳离子共存时对铊吸附进程的影响。结果表明：P-Fe-TiO₂复合材料具有多孔结构，吸附符合单分子层吸附，Langmuir拟合最大吸附容量283.1 mg/g，吸附大约2 h达到平衡，强酸性环境会抑制铊的吸附，随着p H值的升高吸附容量逐渐增大，K(Ⅰ),Na(Ⅰ)离子的存在对吸附干扰较小，Ca(Ⅱ)离子的存在会与Tl(Ⅰ)竞争有效的吸附结合位点，导致吸附效率降低，根据吸附前后材料的XPS表征分析，P-FeN-TiO₂复合材料对Tl(Ⅰ)的吸附机理为Ti-OH、P=O、Fe-OH三种基团与Tl(Ⅰ)发生了络合作用，从而实现铊的去除。     

液膜分离富集,测定水中微量铅

用2,6－二酮吡啶－18－王冠－6（2,6－DKP－18－Crowe－6）、SPAN80、SIOON－Ⅰ（中性油）和CH2Cl4（四氯乙烷）乳状液膜体系,研究了Pb2＋的迁移行为。在适宜条件下8min内Pb2＋的迁移率达99．5％以上,而在这种情况下,许多金属离子（如Cu2＋、Ni2＋、Li＋、K＋、Na＋、Ca2＋、Mg2＋、Ba2＋、Sr2＋、Fe3＋、Al3＋、Zn2＋、Cd2＋和Co2＋等）,都不被迁移,只有Pb2＋能满意的从这些离子中分离出来。该法已成功地用于分离富集、测定水和工业废水中微量铅,相对标准偏差在2．6％以下。结果十分满意。     

工业园区环境污染第三方治理发展实践新趋势

环境污染第三方治理是一种可有效发挥政府、排污主体、市场力量等多方优势,提高环境污染治理效率并降低综合成本的重要模式。工业园区在有限的物理空间内入驻了大量的企业,资源能源消耗和污染产生集中,是环境污染第三方治理重要的实践载体。本文对2016年以来生态环境部（原环境保护部）、国家发展改革委等部门针对工业园区推进环境污染第三方治理的实践创新进行综述,从试点项目、典型模式、成效与挑战等方面对园区已开展的第三方治理实践进行分析,认为第三方治理在推进园区绿色发展中优点突出,已开展大量多样化实践,具有广阔的进一步发展前景,但同时仍需突破机制模式、管理制度等瓶颈。在国家针对工业园区污染防治突出系统优化、资源能源双控、排放提标、精细化管理等趋势下,全面深化环境污染第三方治理的机遇和挑战并存,主要面临着硬件设施和管理体系不平衡不完善两大问题。最后,研究提出了创新第三方环境综合服务和针对“双碳”目标深入推进工业园区第三方污染治理的两方面政策建议,以期为工业园区深化环境污染第三方治理实践创新和促进园区绿色发展提供决策参考。     

Ion partitioning among soil and plant components under drip,furrow, and sprinkler irrigation regimes: field and modeling assessments

Soil and water resources can be severely degraded by salinity when total salt input exceeds output in irrigated agriculture. This study was conducted to examine partitioning of Ca2+, Na+, and Cl- between soil and soybean [Glycine max (L.) Merr.] plants under different irrigation regimes with both field and modeling assessments. In drip and sprinkler treatments, the irrigation water was salinized with NaCl and CaCl2 salts to simulate a Cl- and Na+ dominant saline drainage water. In the furrow irrigation treatment, the soil was salinized, prior to planting, with NaCl and CaCl2 salts to simulate a Cl- and Na+ dominant saline soil. A total of 756 soil and 864 plant samples were collected and analyzed for the salt ions to obtain ion partitioning and mass balance assessments. Modeling of salt ion uptake by plants and distribution in the soil profile was performed with a two-dimensional solute transport model for the three irrigation regimes. Results indicated that about 20% of the applied Ca2+ was recovered in harvested soybean biomass in all treatments. Plant uptake of either Na+ or Cl- was less than 0.5% in the drip and furrow, and about 2% in the sprinkler irrigation treatment. Significant increases in soil salinity were found in the sprinkler plot that received the highest cumulative amount of salts. Simulated ion distributions in the soil were comparable with the measurements. Compared with the total seasonal salt input, mass balances between 65 and 108% were obtained. Most salt inputs accumulate in the soil, and need to be removed periodically to prevent soil salinization.     

A transport model with coupled ternary exchange and chemisorption retention for hydrazinium cations

A numerical model was developed to describe the fate and transport of hydrazinium (N2H5+) and competing Ca2+ and H+ cations applied in acidic solutions to columns of Ca2+/H+-saturated sandy soil during steady saturated flow conditions. Instantaneous ternary H+-Ca2+-N2H5+ cation exchange using the Gaines-Thomas approach was combined with second-order, irreversible, kinetic chemisorption of exchange-phase N2H5+ ions as major retention mechanisms for N2H5+. Exchange-mediated chemisorption is assumed to occur as chemical binding of N2H5+ ions located on carboxyl-group exchange sites to nearby carbonyl groups, consequently decreasing the effective soil cation exchange capacity (CEC). Comparison of simulated and observed breakthrough curves (BTCs) for concentrations of N2H5+ and Ca2+ ions in column effluent was used in model evaluation. The cation transport model with cation exchange coupled with exchange-mediated chemisorption provided a valid first approximation for N2H5+ transport.     

Characterization of cation-pi interactions in aqueous solution using deuterium nuclear magnetic resonance spectroscopy

Chemical interactions of aromatic organic contaminants control their fate, transport, and toxicity in the environment. Recent molecular modeling studies have suggested that strong interactions can occur between the pi electrons of aromatic molecules and metal cations in aqueous solutions and/or on mineral surfaces, and that such interactions may be important in some environmental systems. However, spectroscopic evidence for these so-called cation-pi interactions has been extremely limited to date. In this paper, cation-pi interactions in aqueous salt solutions were characterized via 2H nuclear magnetic resonance (NMR) spin-lattice relaxation times (T1) and calculations of molecular correlation times (tau(c)) for a series of perdeuterated (d6-benzene) benzene-cation complexes. The T1 values for d6-benzene decreased with increasing concentrations of LiCl, NaCl, KCl, RbCl, CsCl, and AgNO3, with the largest effects observed in the AgNO3 and CsCl solutions. Upon normalizing tau(c) values by solution viscosity effects, an overall affinity trend of Ag+ > Cs+ > K+ > Rb+ > Na+ > Li+ was derived for the d6-benzene-cation complexes. The ability of Ag+ to complex d6-benzene was significantly reduced upon addition of NH3, which strongly coordinates Ag+ at high pH. Results with d6-benzene, d8-naphthalene, d2-dichloromethane, and d12-cyclohexane in 0.1 M methanolic salt solutions confirmed that spin-lattice relaxation rates are characterizing cation-pi interactions. The relatively strong cation-pi bonding observed between Ag+ and aromatic hydrocarbons probably results from covalent interactions between the aromatic pi electrons and the d orbitals of Ag+, in addition to the normal electrostatic interaction.     

Heavy metals extraction from contaminated soil: recovery of the flushing solution

The optimum conditions for the recovery of copper from a contaminated soil by using the soil flushing technique are evaluated. Tests on a soil artificially contaminated with copper chloride were carried out in order to evaluate the influence of the speed of percolation and of the chelating agent concentration (aqueous solution of an ethylendiaminotetraacetic acid di-sodium salt Na2-EDTA). At pH=7.3 an efficiency up to 93.9% for copper extraction was achieved by flushing 500 ml of Na2-EDTA 0.05 M solution and 100 ml of pure water at 0.792 cm/h. At these operating conditions the formation of EDTA complexes with other competitive cations (calcium and iron) was negligible. The experimental results were in agreement with the ones obtained using a model describing the chemistry of metal extraction. This model assessed that above pH=6 the formation of calcium and iron EDTA complexes was excluded and only the chelation of copper was allowed. The recovery of 91.6% of EDTA was also achieved by evaporating and acidifying the extracted solution: after filtration, solid EDTA was obtained, through the addition of sodium hydroxide Na2-EDTA. About 99.5% of the extracted copper was finally precipitated under alkaline conditions from the liquid phase.     

Estimating the Unknown Components of Nutrient Mass Balances for Forestry Plantations in Mine Rehabilitation, Upper Hunter Valley, New South Wales, Australia

Commercial forestry plantations as a postmining land use in the Upper Hunter Valley of New South Wales, Australia are restricted by both the poor nutrient availability of mining substrates and low regional rainfall. An experiment was conducted to investigate whether municipal waste products and saline groundwater from coal mining operations could improve early tree growth without impacting on the environment through salt accumulation and/or nutrient enrichment and changes in groundwater quality. Potential impacts were investigated by quantifying the nutrient cycling dynamics within the plantation using an input–output mass balance approach for exchangeable calcium (Ca²⁺), exchangeable magnesium (Mg²⁺), exchangeable potassium (K⁺), exchangeable sodium (Na⁺), nitrogen (N), and phosphorus (P). Measured inputs to and outputs from the available nutrient pool in the 0–30 cm of the overburden subsystem were used to estimate the net effect of unmeasured inputs and outputs (termed “residuals”). Residual values in the mass balance of the irrigated treatments demonstrated large leaching losses of exchangeable Ca, Mg, K, and Na. Between 96% and 103% of Na applied in saline mine-water irrigation was leached below the 0–30-cm soil profile zone. The fate of these salts beyond 30 cm is unknown, but results suggest that irrigation with saline mine water had minimal impact on the substrate to 30 cm over the first 2 years since plantation establishment. Accumulations of N and P were detected for the substrate amendments, suggesting that organic amendments (particularly compost) retained the applied nutrients with very little associated losses, particularly through leaching.     

The effects of throughfall manipulation on soil leaching in a deciduous forest

The effects of changing precipitation on soil leaching in a deciduous forest were examined by experimentally manipulating throughfall fluxes in the field. In addition to an ambient treatment (AMB), throughfall fluxes were reduced by 33% (DRY treatment) and increased by 33% (WET treatment) using a system of rain gutters and sprinklers on Walker Branch Watershed, Tennessee. Soil leaching was measured with resin lysimeters in the O horizons and with ceramic cup lysimeters in the E (25 cm) and Bt (70 cm) horizons. Large and statistically significant treatment effects on N fluxes were found in the O horizons (lower N fluxes in the DRY and higher N fluxes in the WET treatment). Together with the greater O horizon N content observed in the DRY treatment, this suggested that N was being immobilized at a greater rate in the DRY treatment than in the AMB or WET treatments. No statistically significant treatment effects on soil solution were found in the E horizons with the exception of (Ca2+ + Mg2+) to K+ ratio. Statistically significant treatment effects on electrical conductivity (EC), pH, Ca2+, Mg2+, K+, Na+, SO4(2-), and Cl- were found in the Bt horizons due to differences between the DRY and other treatments. Despite this, calculated fluxes of Ca2+, Mg2+, K+, Na+, SO4(2-), and Cl- were lowest in the DRY treatment. These results suggest that lower precipitation will cause temporary N immobilization in litter and long-term enrichment in soil base cations whereas increased precipitation will cause long-term depletion of soil base cations.     

Hydrogeochemical and Isotopic Investigations on Groundwater Salinization in the Datong Basin,Northern China1

Abstract: Analyses of major elements, environmental isotope ratios (δ¹⁸O, δ²H), and PHREEQC inverse modeling investigations were conducted to understand the processes controlling the salinization of groundwater within the Datong Basin. The hydrochemical results showed that groundwater with high total dissolved solid (TDS) concentrations was dominated by sodium bicarbonate (Na‐HCO₃), sodium chlorite (Na‐Cl), and sodium sulfate (Na‐SO₄) type waters, whereas low‐TDS groundwater from near mountain areas was dominated by calcium bicarbonate (Ca‐HCO₃) and magnesium bicarbonate (Mg‐HCO₃) type waters. The characterization of the major components of groundwater and PHREEQC inverse modeling indicated that the aluminosilicate hydrolysis, cation exchange, and dissolution of evaporites (halite, mirabilite, and gypsum) governed the salinization of groundwater within the Datong Basin. The environmental isotope (δ¹⁸O, δ²H) and Cl^?/Br^? ratios revealed the impact of fast vertical recharge by irrigation returns and salt‐flushing water on the groundwater salinization. According to the analyses of major hydrochemical components and PHREEQC inverse modeling, evaporite dissolution associated with irrigation and salt‐flushing practice was probably the dominant controlling factor for the groundwater salinization, especially in the central part of the basin. Therefore, groundwater pumping for irrigation and salt‐flushing should be controlled to protect groundwater quality in this area.     

THE EFFECTS OF DEICING SALTS ON WATER CHEMISTRY IN PINHOOK BOG,INDIANA1

ABSTRACT: A five-year study was conducted to identify the effects of road salt intrusion on the water chemistry of Pinhook Bog following operation of an uncovered salt storage pile adjacent to the bog for ten years. A distinct pattern of elevated salt concentrations was observed in the interstitial waters of the surface peat that corresponded to observed alterations in the bog vegetation. Yearly mean salt concentrations as high as 468 mg/l sodium and 1215 mg/l chloride were recorded in the plant root zone of the peat mat. The salt concentrations decreased significantly each year from 1979 to 1981 throughout the impacted area. Some increases of a lesser magnitude occurred in 1982 and 1983. Analysis of salt movements suggested that vertical transport by water movement was responsible for concentration changes. The major declines in salt levels occurred in the spring following snowmelt and heavy precipitation events. Evapotranspiration during periods of drought resulted in the gradual increases in surface peat salt concentrations. Diverted highway runoff was shown to be the major continuing source of sodium chloride contamination and was the likely source of the elevated calcium, magnesium, potassium, bicarbonate, and pH levels also observed in the impacted area.     

Improving saline-sodic coalbed natural gas water quality using natural zeolites

Management of saline-sodic water from the coalbed natural gas (CBNG) industry in the Powder River Basin (PRB) of Wyoming and Montana is a major environmental challenge. Clinoptilolie zeolites mined in Nevada, California, and New Mexico were evaluated for their potential to remove sodium (Na+) from CBNG waters. Based on the exchangeable cation composition, naturally occurring calcium (Ca2+)-rich zeolites from New Mexico were selected for further evaluation. Batch adsorption experiments were conducted to evaluate the potential of the Ca(2+)-rich natural clinoptilolites to remove Na+ from saline-sodic CBNG waters. Batch adsorption experiments indicated that Na+ adsorption capacity ofclinoptilolite ranged from 4.3 (4 x 6 mesh) to 7.98 g kg(-1) (14 x 40 mesh). Among the different adsorption isotherms investigated, the Freundlich Model fitted the data best for smaller-sized (6 x 8, 6 x 14, and 14 x 40 mesh) zeolites. Passing the CBNG water through Ca(2+)-rich zeolite columns reduced the salt content (electrical conductivity [EC]) by 72% with a concurrent reduction in sodium adsorption 10 mmol 1/2 L(-1/2). Zeolite technology appears to be an effective water treatment alternative to industrial membrane treatment for removing Na+ from poor-quality CBNG waters.