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1.
Lobna Gharbi Tarchouna Patricia Merdy Michel Raynaud Hans-Rudolf Pfeifer Yves Lucas 《Applied Geochemistry》2010
The long-term impact of irrigation on a Mediterranean sandy soil irrigated with Treated wastewater (TWW) since 1980 was evaluated. The main soil properties (CEC, pH, size distribution, exchangeable cations and chloride, hydraulic conductivity) as well as the organic matter and Cu, Cr and Pb speciation in an irrigated soil and a non-irrigated control soil at various soil depths were monitored and compared during a 2 years experiment. In this first part, the evolution of the physico-chemical soil properties was described. The irrigation with TWW was beneficial with regard to water and nutrient supplying. All the exchangeable cations other than K+ were higher in the irrigated soil than in the reference one. A part of the exchangeable cations was not fixed on the exchange complex but stored as labile salts or in concentrated soil solution. Despite the very sandy soil texture, both saturated and unsaturated hydraulic conductivity exhibited a significant diminution in the irrigated soil, but remained high enough to allow water percolation during rainy periods and subsequent leaching of accumulated salts, preventing soil salinization. In the irrigated soil, exchangeable sodium percentage (ESP) exhibited high values (20% on average) and the soil organic C was lower than in the reference. No significant effect was noticed on soil mineralogical composition due to irrigation. 相似文献
2.
污水中的悬浮物、盐分和有机营养物对土壤孔隙状况产生了深刻的影响.通过室内模拟和CT(computed tomography)扫描的方法, 定量研究污水灌溉条件下土壤孔隙数、孔隙度及形态特征.结果表明: 与对照点相比, 污水灌溉区上层土壤总孔隙数和大孔隙数(当量直径≥1.00 mm)均显著升高, 而下层土壤总孔隙数、大孔隙数、粗孔隙数(当量直径为0.26~1.00 mm)、总孔隙度、大孔隙度和粗孔隙度均显著降低(p＜0.05);在模拟悬浮液和盐液灌溉条件下, 土壤总孔隙数、粗孔隙数和粗孔隙度均有所升高, 而大孔隙数、总孔隙度、大孔隙度和孔隙成圆率均有所降低; 在模拟营养液灌溉条件下, 土壤总孔隙数、大孔隙数、粗孔隙数和粗孔隙度均有所增加, 而孔隙成圆率有所降低; 对于研究区土壤来说, 悬浮液灌溉对土壤孔隙的影响效应强于盐液灌溉; 对于同种性质的污水灌溉来说, 污灌对对照点土壤孔隙的影响效应强于污灌区土壤. 相似文献
3.
主要探讨水稻田休耕期间蓄水对休耕后土壤肥力之影响。选择两块水稻田区,在水稻收割后,将田区翻耕一次。一田区以人工连续灌溉,蓄存水量于田区;另一田区则为天然蓄水。在每一田区四边及中央处,以10cm为一层采取土样,取至60cm。再将每一层土样气干后,通过0.42mm筛网土样混合,分析田区同一层在不同时段与不同深度下之pH值、电导度值、有机质、全氮、有效磷、钙离子、镁离子、钾离子及钠离子之变化。试验结果显示:休耕后水稻根系腐化,造成土壤有机质以及有效磷显著的增加。蓄水后天然蓄水田区有机质和有效磷分别增加51%及88%,连续蓄水田区分别增加13%和69%。而天然蓄水田区镁、钾、钠分别降低35%、24%和47%,连续蓄水田区分别降低29%、14%及41%。 相似文献
4.
以淮南采煤沉陷区土壤为研究对象,测试分析了样品中汞的含量,结合土壤pH值、有机质含量特征,探讨了采煤沉陷区土壤中汞的时空分布特征。结果表明:与未沉陷区土壤相比,沉陷区土壤有机质破坏严重,最高下降了46%;采煤沉陷区土壤中汞的含量为0.013~0.050 mg/kg,平均值为0.027 mg/kg,69.7%的采样点超过了淮南市土壤背景值;沉陷8 a后土壤汞含量最高,为0.033 mg/kg,是未沉陷土壤汞含量的1.74倍,且随着沉陷时间的增加,土壤中汞存在富集趋势;水稻土壤汞富集能力最高,高于玉米和大豆土壤;在垂直剖面上,汞含量由表层向下依次降低;且汞与pH值表现出显著负相关,有机质与汞显著正相关。 相似文献
5.
通过对典型环境功能区张士灌区包气带剖面样品和含水层样品的分析检测,比较和总结了菲的垂向分布特征,研究了总有机碳、粘粒含量、土壤含水率对菲垂向分布与迁移的影响规律和机理。对具有代表性采样点的研究表明,菲总含量在剖面中的变化趋势总体上随剖面的加深而降低,以犁底层为界,表层土壤(5~20 cm)菲含量随剖面深度变化平缓。同时分别对菲含量与总有机碳、土壤粘粒含量、土壤含水率进行二元相关分析,计算出的Pearson系数表明:土壤中总有机碳、土壤粘粒含量是影响菲垂向迁移的重要因素,而土壤含水率对菲垂向分布影响不大。同时利用SPSS的因子分析法进一步确定总有机碳是制约菲垂向运移的主要因素。 相似文献
6.
Rakia S’habou Moncef Zairi Amjed Kallel Abdelwaheb Aydi Hamed Ben Dhia 《Environmental Geology》2009,58(3):679-686
Olive oil is a typical and valuable agro-industrial product in Mediterranean countries. In Tunisia, olive mill wastewaters
(OMW) reach an amount of about 1,000,000 t year−1 and constitute a serious organic pollution risk because of the high chemical oxygen demand values and the presence of phytotoxic
and antibacterial polyphenols. OMW have been generally stored in pond sites to be eliminated by natural evaporation or valorised
by spreading on cultivated soils or by composting. Many researches on the interactions of OMW with soils at laboratory scale
(columns) have been reported, but less attention have been paid to the effect of OMW on soils at field scale. The aim of this
work is to investigate an area used for >15 years as an uncontrolled OMW pond site. The transformations of soil properties
and groundwater occurring during OMW storage were characterised by the pH, phenolic contents, electrical conductivity (EC),
moisture content and organic contents. The soil samples were taken from two borings and compared to those of a control one
located near the pond site. Groundwater samples were taken on the accessible and nearest water wells to the evaporation ponds.
The permeable silty and sandy layers in the site support the infiltration of OMW near the evaporation ponds. This infiltration
has reached a depth of 6 m at a distance of almost 50 m laterally. The results show that the OMW infiltration in the subsoil
has affected the pH, EC, organic content, phenolic compounds and the moisture. 相似文献
7.
By sampling in the field and analyzing the soil samples in the laboratory in 1982 and 2005 the soil fertility data were obtained.
Through application of geo-statistics combined with GIS, the temporal–spatial variability of the pH, organic matter, total
nitrogen, total phosphorus and total potassium in soil of Xiaojiang watershed from 1982 to 2005 were analyzed. Results showed
that: (1) the pH value and total potassium in soil showed an increasing trend, but the organic matter, total nitrogen and
the total phosphorus in soil declined in the past 20 years in Xiaojiang watershed, (2) the parameters fitted by semivariogram
models for fertility indices changed significantly in the past 20 years and (3) the result estimated by ordinary Kriging indicated
the spatial pattern of the soil fertility indices changed significantly in the past 20 years. The soil pH increased in the
east and southeast, but decreased in the middle of the watershed. The organic content of the soil matter decreased in the
east, southeast and southwest, but increased in the northeast and middle of the watershed. The total nitrogen content of the
soil decreased in the east, but increased in the middle of watershed. The total phosphorus content of the soil decreased in
the whole watershed. The total potassium content of the soil increased in the southwest and southeast, but decreased in the
middle of the watershed and (4) the change of land use and soil management measures was the main driving force of variability
of soil properties. 相似文献
8.
The influence of Zn speciation on Zn transport by drainage from different soils to surface water is examined in a stream catchment
in an agricultural area. Drainage waters were collected from two types of soils, a mineral soil (MS) and a soil rich in organic
matter (OS) by means of artificial drainage pipes. The speciation of dissolved Zn in the stream and the drainage waters was
determined using ligand-exchange and voltammetry. About 50–95% of dissolved Zn is bound in strong complexes, and the free
Zn2+ ion concentration is in the range of 1–16% of dissolved Zn. A substantial part of Zn is present in weaker organic or inorganic
complexes. The simulated Zn speciation using the WHAM VI model is compared to the determined speciation. Free Zn2+ concentrations predicted by the WHAM VI model are generally higher than the analytically determined free Zn2+, but are mostly within the same order of magnitude. Effects of different soil organic matter content on Zn speciation and
transport are discussed. Zn speciation in the drainage at the OS site is influenced by the distribution of organic matter
between the solid and solution phase. The abundant organic Zn complexes in solution contribute to facilitate Zn transport
from soil into surface waters, through the drainage at the OS site. Drainage from the OS site contributes about twice as much
Zn input to the receiving water as the MS soil, as related to specific area. The mineral soil contains much lower organic
matter, and a part of Zn bound with inorganic phases can hardly be released by dissolved organic ligands, leading to much
higher Zn retention at the MS site. 相似文献
9.
10.
Lianchuan Zhou Xiaomin Chen Xiaoliang Li Xinqiang Yang Daimin Huang Wen Xia Chen Cui 《Environmental Earth Sciences》2011,63(2):273-278
The characteristics of nitrate vertical transport in soils collected from Libo and Puding in Guizhou Province were studied
by simulating soil column in laboratory. The results were as follows: (1) Vertical transport velocity of nitrate decreased,
and the breakthrough curves (BTCs) of nitrate were more dispersed, in each horizon from surface layer to bottom layer in every
soil profile. As rocky desertification progressed, the BTCs experienced a gentle up and down trend, and tailing was more obvious.
(2) An analytical solute transport model (CXTFIT 2.0) was used to estimate nitrate dispersion coefficient (D) and average pore water velocity (V) from the observed BTCs. The results showed that CXTFIT 2.0 model was suitable in fitting the nitrate transport in these
soils. The dispersion coefficient was found to be a function of average pore water velocity. (3) The transport of nitrate
was mainly affected by the soil structural coefficient. As soil structural coefficient decreased, nitrate outflow was retarded,
and the peak concentration was reduced. Soil bulk density, organic matter, and clay also affected the vertical transport of
nitrate. Low bulk density, clay content, and high organic matter content were each associated with faster nitrate transport. 相似文献
11.
防渗对堤坝等水利工程、地下工程和污染物迁移都具有重要意义。基于自然灰化土层形成过程中因金属离子和有机质络合反应形成不透水土层的过程,提出了利用六水合氯化铝（AlCl3·6H2O）和有机质（OM）相互反应生成Al-OM絮状物来降低渗透系数的方法。开展了系列的注入试验,探究了浆液浓度、注浆速度和砂土颗粒级配对渗透系数降低和形成屏障长度的影响。研究结果表明：该方法可以有效地降低砂土的渗透性;渗透系数降低的速度随着浆液中Al-OM絮状物浓度的增大而增加;由于絮状物浓度的增加,孔隙堵塞的速度增快,从而阻止了其继续扩散,形成的屏障长度随之减小;Al-OM絮状物的尺寸随注浆速度的增大而减小。当注浆速度较大时,Al-OM絮状物的尺寸较小,因此渗透系数降低慢而扩散距离远。砂土的颗粒级配对渗透系数降低有重要影响,粗颗粒含量越大,渗透系数降低越小。 相似文献
12.
Effects of biochar, cow bone, and eggshell on Pb availability to maize in contaminated soil irrigated with saline water 总被引：2，自引：0，他引：2
Yaser A. Almaroai Adel R. A. Usman Mahtab Ahmad Deok Hyun Moon Ju-Sik Cho Young Kyoo Joo Choong Jeon Sang Soo Lee Yong Sik Ok 《Environmental Earth Sciences》2014,71(3):1289-1296
Toxicity of heavy metals adversely affects environment and human health. Organic materials derived from natural matters or wastes have been applied to soils to reduce the mobility of contaminants such as heavy metals. However, the application of cow bone powder (CB), biochar (BC), and eggshell powder (ES) is rarely investigated for the reduction of Pb bioavailability in soils irrigated with saline water. The objective of this study was to assess the effectiveness of CB, BC, and ES additions as immobilizing substances on Pb bioavailability in shooting range soil irrigated with deionized and saline water. Each additive of CB, BC, and ES at 5 % (w/w) was mixed with soils and then the deionized and saline water were irrigated for 21 days. With deionized water irrigation, the soils treated with CB, BC, and ES exhibited higher pH when compared with saline water irrigation. With saline water irrigation, the electrical conductivity, water-soluble anions, and cations were significantly increased in soils treated with CB, BC, and ES. The water-soluble Pb in soils treated with CB, BC, and ES was significantly decreased with saline water irrigation. On the other hand, the water-soluble Pb in soil treated with CB was increased with deionized water irrigation. Only BC with saline water irrigation decreased the Pb concentration in maize shoots. 相似文献
13.
Comprehensive GC/MS analysis was applied to both the mobile liquid phase (seepage water) and the immobile solid matter of discrete layers derived from a waste deposit landfill. The vertical distribution of organic compounds supports information on the transport, transfer and transformation processes with depth and, consequently, with time.Numerous low molecular weight organic contaminants of natural and xenobiotic origin were identified and partially quantified. Several were selected to act as molecular indicators for different processes. Interpretation of their occurrence and concentration profiles (considering possible waste sources) and their molecular properties allowed us to (i) differentiate immobile and mobile fractions, (ii) reveal restrictions in the vertical transport by transfer processes between particulate and water phase, (iii) identify dynamic accumulations of individual contaminants and (iv) estimate approximate residence times. In addition, intensive degradation processes were pointed out for the natural fraction of the organic matter by way of determination of specific transformation products. Besides the transformation of natural components, transformation of numerous xenobiotics was recognised. In particular, with respect to an important group of contaminants, the phthalate-based plasticisers, a detailed view of (i) the influence of transfer and transport phenomena on transformation processes as well as (ii) the consecutive appearance of different degradation steps in both seepage water and solid waste was pointed out. The information provides a valuable base for the prediction of the long term behaviour of organic contaminants in waste deposit landfills. 相似文献
14.
Disturbances have the potential to reduce soil water and nutrient retention capacity by decreasing soil organic matter (SOM), which is particularly true for sandy soils characterized by an inherent low capacity to retain nutrients and water. To restore degraded areas, several works have shown positive effects of organic matter inputs on soil properties and plant growth. Despite these promising results, it is still unclear how organic matter inputs and plant growth modify the balance between soil nutrient and water supply. The objectives of the present work were (1) to evaluate the effects of biosolids compost and municipal compost addition on plant available water (PAW), soil moisture and soil temperature in a burned sandy soil of NW Patagonia (Argentina), and (2) to relate PAW and soil moisture with bulk density, soil organic carbon, nutrient availability (inorganic and potential mineralized nitrogen (N), extractable phosphorous) and aboveground phytomass. An experiment with excised vegetation and watering was also conducted. Compost application increased SOM, but it was insufficient to increase PAW. The increase in potential mineralized N in the amended soils indicated that during moist periods (and adequate temperatures), N uptake was increased, enhancing plant growth. As a consequence, higher plant water consumption in amended treatments resulted in lower soil moisture than in non-amended plots during the vegetative growth period that coincides with decreasing precipitation. Results indicate that a relatively high dose of compost (40 Mg ha?1) applied to a sandy soil, contributed to increase nutrient availability and consequently, aboveground phytomass and water consumption. 相似文献
15.
硒是重要的人体必需微量元素,对特色农业发展起着重要的助力作用。碧江区土壤硒元素含量平均值超过贵州省及全国硒含量均值。富硒耕地面积达29426 8万亩,具有较大的富硒资源开发潜力。成土母岩为炭质页岩所形成的土壤中硒元素含量高于其他类型成土母岩所形成的土壤,强酸性土壤中硒元素含量平均值高于其他酸碱度等级土壤,水田中硒元素含量平均值显著高于旱地、果园、水浇地等其他类型土地。成土母质是土壤中硒元素的主要来源及影响因素,pH值、有机质、土壤质地等理化条件对土壤硒元素有一定影响。 相似文献
16.
土地利用对溶丘洼地土壤容重、水分和有机质空间异质性的影响——以南洞流域驻马哨洼地为例 总被引：1，自引：1，他引：0
为了探究溶丘洼地土壤空间异质性及其影响因素,本文以驻马哨溶丘洼地为研究对象,利用经典统计学和地统计学的方法,从不同土地利用、坡度、坡向、土壤深度分析土壤容重、水分及有机质的空间异质性。结果表明:（1）土壤有机质为强变异,变异系数为0.71,容重和水分变异系数分别为0.15、0.11,属中等变异,土壤容重和水分呈极显著负相关,和有机质呈显著负相关,相关系数分别为-0.609、-0.581;（2）块基比介于0.78~0.97,随机部分引起的空间变异程度较大,空间自相关较小,且模型拟合较好。（3）耕地土壤有机质、水分含量最低,容重最大,而灌木土壤反之;（4）北坡土壤容重高于南坡,变异系数小于南坡;而土壤水分、有机质低于南坡,变异系数高于南坡。从不同坡位、坡向的比较中,皆体现了土地利用对土壤空间异质性的影响。在土地利用作为主要因素的影响下,驻马哨洼地土壤水分、容重、有机质由随机部分引起的空间变异增加,空间自相关减小。 相似文献
17.
Polychlorinated biphenyls (PCBs) are the main constituents of clophen (the liquid of the electric transformers and capacitors)
and have been characterized as potential human carcinogens. PCBs can be a hazardous contaminant of soil and groundwater. We
used the mathematical model variably saturated 2D flow and transport (VS2DT model) to simulate the transport of PCBs from
the soil surface to groundwater for a time period of 30 years. We also used a mathematical model to simulate the colloid-facilitated
PCB transport, under saturated flow conditions. The results showed that PCBs dissolved in water cannot be transported to large
depths in unsaturated soils, because of their strong sorption onto soil and low solubility in water. For soils with very low
or no organic matter content, PCB transport is much faster and the probability of groundwater contamination is much higher.
PCBs can partition to colloids originating from dissolved organic matter in groundwater. Colloid-facilitated PCB transport
is faster compared to PCB transport in aqueous solution with no colloids present. 相似文献
18.
The long-term impact of irrigation on a Mediterranean sandy soil irrigated with treated wastewater (TWW) since 1980 was evaluated. The main soil properties (CEC, pH, size distribution, exchangeable cations and chloride, hydraulic conductivity) as well as the organic matter and Cu, Cr and Pb speciation in an irrigated soil and a non-irrigated control soil at various soil depths were monitored and compared during a 2 year experiment. In this second part, we focused on Cu, Cr and Pb behaviour in relation with soil organic carbon (SOC). Soil samples were collected every 3 months during 2 years at the depths 0–20, 20–40 and 40–60 cm and were analysed for exchangeable and total metals, organic carbon content, metal sequential extraction and humic substances – Humic Acids (HA), Fulvic Acids (FA) and Non-Humified Fraction (NHF). Long-term irrigation with a domestic treated wastewater (TWW) may be considered safe with regard to trace metal accumulation in soil. Irrigation lowered the HA and NHF fractions of SOC and made the FA fraction more mobile. Cu bound preferentially to the SOC fraction, Cr was found mainly in the reducible fraction and Pb was bound to all fractions indiscriminately. Cu exhibited a high affinity for the HA fraction, while Pb and Cr had a high affinity for the FA fraction, which indicates a greater mobility of the organically-bound Pb and Cr than of the organically-bound Cu. Evaluation of the potential metal mobility has to take into account not only the usual speciation between labile, reducible and oxidisable fractions, but also the nature of the SOC responsible for the oxidisable fraction. 相似文献
19.
Doongar R. Chaudhary Aditya P. Rathore Bhavanath Jha 《International Journal of Environmental Science and Technology》2016,13(9):2199-2208
Irrigation with diluted seawater would be an alternative water resource which can play an important role under scarce resources of freshwater for promoting agricultural production in coastal areas. Salvadora persica Linn. was irrigated with different concentrations of seawater (0, 10, 20, 40, 60, 80 and 100 % seawater), and their effect on plant growth, nutrient contents in soil and plants, shift in soil microbial community structure (phospholipid fatty acid; PLFA) and community-level physiological profiling (CLPP, Biolog ECO MicroPlate) were studied. Plant dry matter was significantly increased with all seawater treatments, and highest increase was at 20 % seawater treatment. Sodium and chloride contents were significantly increased, whereas ratios of K/Na and Ca/Na were significantly decreased in plants with seawater irrigation. Soil electrical conductivity (EC), available K and Na were significantly increased with increasing the concentration of seawater. Total PLFA concentration and PLFA profile of soils were used as indices of total microbial biomass and community composition, respectively. The concentrations of total PLFA, gram-positive, gram-negative and actinomycetes biomarker PLFAs were significantly reduced at 20, 40, 80 and 40 % concentrations of seawater, respectively. The application of different concentrations of seawater induced a clear shift in the soil microbial community structure toward the bacterial abundance. The microbial community structure and community-level physiological profiling in seawater irrigation treatments had significantly differentiated. It can be concluded that irrigation with different concentrations of seawater had significant impact on soil chemical and microbial properties which is attributed due to the salinity stress. 相似文献
20.
在贵阳市南明区河水环境综合整治项目二期工程施工中,针对软土地基砂袋围堰易变形失稳、承载能力差等问题,开展了软土地基砂袋围堰施工技术及变形失稳影响因素分析。本文基于实际施工工况条件,在考虑最不利荷载作用下,采用有限元法对软地基砂袋围堰进行了模拟分析,并以围堰倾角和围堰宽度作为影响因素,获得了相同水位条件下围堰变形情况,提出了最优的砂袋围堰堆砌方案,通过研究提高了砂袋围堰受力性能,降低了变形失稳破坏的风险,并将其理论模拟优化结果应用于实际挡水围堰施工承载力中,加快了施工进度,保证了工程质量,可为后续类似围堰施工提供理论支持。 相似文献