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1.
Effects of super absorbent polymers on soil microbial properties and Chinese cabbage (Brassica chinensis) growth 总被引：1，自引：0，他引：1
Purpose
New water retention materials, super absorbent polymers (SAPs), have shown the potential to improve some soil physicochemical properties and promote growth of some crop species in arid and semi-arid areas. However, the impacts of SAPs on soil microbial properties are unclear. This study was conducted to clarify the effects of two SAPs on soil microbial properties and Chinese cabbage (Brassica chinensis) growth under different water conditions in the greenhouse.Materials and methods
Experimental conditions included different irrigation conditions and different quantities of SAPs. Chinese cabbage was harvested after 1-month growth in the greenhouse. Meanwhile, soil samples were collected and sieved (<2-mm mesh). Some of the soils were kept at ?4 °C for analysis of soil physicochemical properties, and some at ?20 °C for analysis of soil microbial properties. Chinese cabbage samples were thoroughly washed with deionized water for the measurement of fresh weight, shoot length, and root length.Results and discussion
The effects from SAPs were not obvious under water sufficient (WC1, watered every 2 days, and WC2, watered every 4 days) since plant properties were smaller in some SAP treatments than those in control. However, under water deficit (WC3, watered every 8 days), there were significant differences in plant shoot length and fresh weight between SAP treatments. There were also significant differences in relative soil water content between water condition (WC) or SAP treatments. The SAPs were beneficial for the formation of large aggregates. Under WC3, the soil organic matter (SOM) increased by 16.9 and 11.5 %, soil microbial biomass C (SMBC) by 32.5 and 19.3 %, and soil microbial respiration (SMR) by 52.1 and 37.2 % with Jaguar C (JC) and Jaguar S (JS), respectively. Under WC1 and WC2, significantly higher copy numbers of AOA in bulk treatment of JC were found compared with control treatment in this study. Under water deficit, the abundance of bacteria was significantly increased by application of SAPs. For almost every property of soil and plant, JC was showing better effects than JS.Conclusions
Our results showed that cabbage growth was restricted under water-deficit conditions and the application of SAPs could conserve soil water and be useful for increasing cabbage growth under water deficit, improving SOM, SMBC, and SMR under different WC, and stimulating amoA gene AOA copy numbers and bacterial gene copy numbers. Thus, there should be no adverse effects of SAP application on soil microbial environment and Chinese cabbage growth. 相似文献2.
Environmental impact of two organic amendments on sorption and mobility of propachlor in soils 总被引：1，自引：1，他引：0
Jiajun Zhang Lijiao Yang Lina Wei Xiao Du Lingling Zhou Lei Jiang Qing Ding Hong Yang 《Journal of Soils and Sediments》2012,12(9):1380-1388
Purpose
The purposes of this study were to understand the sorption?Cdesorption characteristics of propachlor in three types of soils with added solid organic matters and the effect of solid organic matters on propachlor mobilization in soil microstructures.Materials and methods
Three soil types, Eutric gleysols (EG), Hap udic cambisols (HUC), and Haplic alisol (HA), along with the lakebed sludge (SL) and pig manure compost (PMC), were used in the study. The sorption and desorption experiments were carried out using the standard batch equilibration method. Soil column leaching was performed with soil samples packed into PVC columns. Soil thin-layer chromatography was performed using soils and water mixture spread on a 0.5?C0.7-mm thick layer over 20?×?10-cm glass plates.Results and discussion
Propachlor was shown to be more mobile in EG and HUC than in HA. Application of PMC and SL to soils affected the propachlor mobilization in the soils. Using batch experiment, soil column, and soil thin-layer chromatography, we showed that addition of SL and PMC increased the sorption and decreased desorption of propachlor in the soils. Addition of PMC and SL reduced the total concentration of propachlor in the soil leachate and migration of propachlor in the soil profiles. Physicochemical properties of the three soils were analyzed and showed that the content of organic carbon (in percentage) was higher in Haplic alisol than in Eutric gleysols and Hap udic cambisols.Conclusion
The soil organic matter played critical roles in modifying the absorption and mobility of organic chemicals (e.g., herbicide and contaminants) in soil ecosystem. 相似文献3.
Retention and release of diethyl phthalate in biochar-amended vegetable garden soils 总被引：1，自引：0，他引：1
Xiaokai Zhang Lizhi He Ajit K. Sarmah Kunde Lin Yingkun Liu Jianwu Li Hailong Wang 《Journal of Soils and Sediments》2014,14(11):1790-1799
Purpose
Diethyl phthalate (DEP) is one of the most commonly used plasticizers as well as a soil contaminant. Using biochar to remediate soils contaminated with DEP can potentially reduce the bioavailability of DEP and improve soil properties. Therefore, a laboratory study was conducted to evaluate the effect of biochar on soil adsorption and desorption of DEP.Materials and methods
Two surface soils (0–20 cm) with contrasting organic carbon (OC) contents were collected from a vegetable garden. Biochars were derived from bamboo (BB) and rice straw (SB) that were pyrolyzed at 350 and 650 °C. Biochars were added to two types of soil at rates of 0.1 and 0.5 % (w/w). A batch equilibration method was used to measure DEP adsorption-desorption in biochar treated and untreated soils at 25 °C. The adsorption and desorption isotherms of DEP in the soils with or without biochar were evaluated using the Freundlich model.Results and discussion
The biochar treatments significantly enhanced the soil adsorption of DEP. Compared to the untreated low organic matter soil, the soils treated with 0.5 % 650BB increased the adsorption by more than 19,000 times. For the straw biochar treated soils, the increase of DEP adsorption followed the order 350SB?>?650SB. However, for the bamboo biochars, the order was 650BB?>?350BB. Bamboo biochars were more effective than the straw biochars in improving soils’ adsorption capacity and reducing the desorption ability of DEP.Conclusions
Adding biochar to soil can significantly enhance soil’s adsorption capacity on DEP. The 650BB amended soil showed the highest adsorption capacity for DEP. The native soil OC contents had significant effects on the soils’ sorption capacity treated with 650BB, whereas they had negligible effects on the other biochar treatments. The sorption capacity was affected by many factors such as the feedstock materials and pyrolysis temperature of biochars, the pH value of biochar, and the soil organic carbon levels. 相似文献4.
Gabriele E. Schaumann Daniela Gildemeister Yamuna Kunhi Mouvenchery Sandra Spielvogel Dörte Diehl 《Journal of Soils and Sediments》2013,13(9):1579-1588
Purpose
Nutrient release, soil wettability, water binding, and matrix rigidity of soil organic matter (SOM) can be affected by cross-links between segments of SOM, cations, and water molecule bridges (WaMB). Not all cation effects on SOM can be explained with the currently accepted idea that multivalent cations cross-link organic matter segments via direct cation bridges (CaB). The objective was to understand these interactions and their effect on SOM matrix rigidity and wettability.Materials and methods
We modified cation composition of two peats and an organic surface layer (OSL) using cation exchange resin to remove cations and solutions of Na+, Ca2+, or Al3+ to enrich samples with cations. SOM matrix rigidity was determined at 4 and >8 weeks after treatment via the WaMB transition temperature T*, using differential scanning calorimetry. Wettability was measured via sessile drop contact angle (CA).Results and discussion
The effect of cation removal on T* depended on cation exchange capacity and initial cation content. Cation addition to OSL increased T*. This effect increased with increasing cation loading and valency, and T* correlated with CA. Classical cross-linking can neither explain the higher heterogeneous matrix of Ca-treated than Al-treated samples nor the aging-induced convergence of T* for different cations and concentrations. The latter is likely due to interaction between CaB and WaMB in SOM.Conclusions
Associations of CaB and WaMB evolve slowly and form a supramolecular network in SOM. Those dynamic associations can fix molecular arrangements inducing water repellency and increase kinetic barriers for the release and uptake of water and nutrients from aged soil. 相似文献5.
Guixiang Zhang Xitao Liu Ke Sun Qiusheng He Tianwei Qian Yulong Yan 《Journal of Soils and Sediments》2013,13(9):1600-1610
Purpose
Biochars are increasingly recognized as effective, inexpensive, and environmentally friendly sorbents for abating organic contaminants. In this study, the sorption and competitive sorption characteristics of simazine (SZ), metsulfuron-methyl (ME), and tetracycline (TC) to corn straw biochars and soil were examined to understand the interactions of herbicides and antibiotics with biochars and the potential role of biochars as engineered sorbents.Materials and methods
Biochars were obtained by pyrolyzing corn straw at 400, 500, and 600 °C for 6 h under oxygen-limited conditions and were characterized via elemental analysis, N2-BET surface area determination, 13C nuclear magnetic resonance spectroscopy, and Fourier transform infrared spectroscopy. Soil was collected from North Tanggu Farm in Tianjin, and its organic carbon, cation exchange capacity, and particle size distribution were analyzed. The batch sorption experiments were performed to obtain the sorption isotherms of SZ, ME, and TC to biochars and soil.Results and discussion
The biochars that were pyrolyzed at higher temperatures had higher sorption affinities for SZ, ME, and TC, which may be due to the enhancement of hydrophobic interactions, charge transfer (π–π*) interactions, and pore-filling mechanism. The sorption affinities for these compounds to all biochars decreased in the order SZ?>?TC?>?ME, indicating that the neutral molecule with a stronger hydrophobicity is more easily adsorbed by biochars. For soil, the decrease of the sorption affinities followed the order TC?>?SZ?>?ME due to the high sorption affinity of TC with clays in the soil. Moreover, the sorption affinities of TC by biochars were lower than by soil, indicating that corn straw biochars may be not an ideal sorbent for the immobilization of TC. Biochars were much more effective in sorbing SZ and ME than soil, indicating that corn straw biochars can potentially prevent transport of the herbicides to surface and ground water. Nevertheless, the presence of TC significantly hinders biochar adsorption of SZ and ME, implying that the coexisting contaminants should be considered when developing biochars as engineered sorbents.Conclusions
The observations in this study demonstrated that the sorption of organic contaminants by biochars is dependent on the properties of the biochars and the molecular structures of the contaminants. Corn straw biochars effectively retain SZ and ME and hinder their transportation to surface and ground water; however, the coexisting contaminants should be considered. Our results will be helpful for designing biochars as engineered sorbents for environmental applications. 相似文献6.
Purpose
We review 2,4-dichlorophenoxyacetic acid (2,4-D) and other phenoxy herbicide sorption experiments.Methods
A database with 469 soil–water distribution coefficients K d (in liters per kilogram) was compiled: 271 coefficients are for the phenoxy herbicide 2,4-D, 9 for 4-(2,4-dichlorophenoxy)butyric acid, 18 for 2-(2,4-dichlorophenoxy)propanoic acid, 109 for 2-methyl-4-chlorophenoxyacetic acid, 5 for 4-(4-chloro-2-methylphenoxy)butanoic acid, and 57 for 2-(4-chloro-2-methylphenoxy)propanoic acid. The following parameters characterizing the soils, solutions, or experimental procedures used in the studies were also compiled if available: solution CaCl2 concentration, pH, pre-equilibration time, temperature, soil organic carbon content (f oc), percent sand, silt and clay, oxalate extractable aluminum, oxalate extractable iron (Oxalate Fe), dithionite–citrate–bicarbonate extractable aluminum, dithionite–citrate–bicarbonate extractable iron (DCB Fe), point of zero negative charge, anion exchange capacity, cation exchange capacity, soil type, soil horizon or depth of sampling, and geographic location. K d data were also compiled characterizing phenoxy herbicide sorption to the following well-defined sorbent materials: quartz, calcite, α-alumina, kaolinite, ferrihydrite, goethite, lepidocrocite, soil humic acid, Fluka humic acid, and Pahokee peat.Results
The data review suggests that sorption of 2,4-D can be rationalized based on the soil parameters pH, f oc, Oxalate Fe, and DCB Fe in combination with sorption coefficients measured independently for humic acids and ferrihydrite, and goethite.Conclusions
Soil organic matter and iron oxides appear to be the most relevant sorbents for phenoxy herbicides. Unfortunately, few authors report Oxalate Fe and DCB Fe data. 相似文献7.
Purpose
Peatland soils play an important role in the global carbon (C) cycle due to their high organic carbon content. Lowering of the water table e.g. for agricultural use accelerates aerobic secondary peat decomposition and processes of earthification. Peatlands change from C sinks to C sources. We characterized soil organic matter (SOM) with special attention to human impact through drainage. Our aim was to gain knowledge of SOM quality and soil-forming processes in drained fen soils in northeastern Germany.Materials and methods
Through techniques of representative landscape analysis, we identified two typical and representative sampling sites in different stages of land use, representing the most important hydrogenetic mire types in northeastern Germany. We adapted chemical fractionation procedures which include hot water extraction (Chwe and Nhwe) for determination of the labile fraction. Furthermore, a stepwise acid hydrolysis procedure was performed to measure the chemical recalcitrant part of SOM as it is more resistant to biodegradability.Results and discussion
Total organic C decreased with increasing human impact and intensity of drainage. Conversely, Chwe and Nhwe concentrations increased with increasing drainage and human impact. In contrast, the more recalcitrant fractions increased with soil depth.Conclusions
Generally, there is a lack of existing data about SOM quality and the factors controlling its stability and decomposition in fen soils. For northeastern German fen soils, the data are even more inadequate. Influence of drainage seems to overlap natural influences of site on SOM quality. The used extraction scheme was suitable for the chemical fractionation of SOM into labile and more recalcitrant parts. 相似文献8.
Georg Waldner Wolfgang Friesl-Hanl Georg Haberhauer Martin H. Gerzabek 《Journal of Soils and Sediments》2012,12(8):1292-1298
Purpose
The sorption behavior of the herbicide 4-chloro-2-methylphenoxyacetic acid (MCPA) to three different artificial soil mixtures was investigated. Artificial soils serve as model systems for improving understanding of sorption phenomena.Materials and methods
The soils consisted of quartz, ferrihydrite, illite, montmorillonite, and charcoal. In a previous study, several selected mixtures had been inoculated with organic matter, and microbial aging (incubation) had been performed for different periods of time (3, 12, and 18?months) before conducting the sorption experiments. The effect of this pre-incubation time on the sorption behavior was determined. Interaction of MCPA with soil surfaces was monitored by aqueous phase sorption experiments, using high-performance liquid chromatography/ultraviolet and in selected cases Fourier-transformed infrared spectroscopy.Results and discussion
The sorption behavior showed large differences between differently aged soils; Freundlich and linear sorption model fits (with sorption constants K f , 1/n exponents, and K d values, respectively) were given for pH?=?3 and the unbuffered pH of ??7. The largest extent of sorption from diluted solutions was found on the surfaces with a pre-incubation time of 3?months. Sorption increased at acidic pH values.Conclusions
Regarding the influence of aging of artificial soils, the following conclusions were drawn: young artificial soils exhibit stronger sorption at lower concentrations, with a larger K f value than aged soils. A correlation with organic carbon content was not confirmed. Thus, the sorption characteristics of the soils are more influenced by the aging of the organic carbon than by the organic carbon content itself. 相似文献9.
Fractal characterization of soil particle-size distribution under different land-use patterns in the Yellow River Delta Wetland in China 总被引：1，自引：0，他引：1
Gao Peng Niu Xiang Sheng-qiao Lv Guang-can Zhang 《Journal of Soils and Sediments》2014,14(6):1116-1122
Purpose
Soil particle-size distribution (PSD) is an important soil physical property. Single- and multi-fractal models are increasingly used to characterize soil properties and may provide additional information. The Yellow River Delta is one of the best representative examples of river ecosystem wetlands in the world. In this area, different land resource development patterns strongly influence soil structure and fertility. Here, the single- and multi-fractal characterizations of soil PSD were determined based on fractal theory, and the correlations between PSD and soil organic matter (SOM) across different land-use patterns were studied.Materials and methods
The study site was located in a typical area of the Yellow River Delta Wetland in Shandong Province in China. The tested soil samples were obtained from areas with four different land-use patterns, including integrated Robinia pseudoacacia and grass cover land (RPG), well-covered European and American poplar forestland (EAP), cropland used for growing cotton (COT), and waste grassland (WAG). Soil samples were air-dried and passed through a 2-mm screen. Based on the international system of soil size fraction, the soil PSD was described according to the percentages of clay, silt, and sand. The clay, silt, and sand fractions were determined using a laser particle size analyzer. The fractal characterizations of soil PSD were determined using the single- and multi-fractal methods.Results and discussion
The single-fractal dimension (D) of the different land-use patterns varied greatly (between 2.4657 and 2.6789). The D values of the RPG and EAP were the greatest, which corresponded to the soils with the greatest silt content and the lowest sand content. In contrast, the D value of the WAG was the smallest, which corresponded with the lowest clay content and the greatest sand content. These results indicated that D was directly proportional to clay content and inversely proportional to sand content. The multi-fractal parameters of the soil PSD, capacity dimension (D 0), information dimension (D 1), and information dimension?/?capacity dimension (D 1?/?D 0), followed a regular trend due to different land-use patterns. These parameters decreased in the following order: RPG?>?EAP?>?COT?>?WAG. In addition, the PSD of the RPG and EAP varied widely and was more heterogeneous than the PSD of the COT and WAG. Furthermore, the single- and multi-fractal parameters were significantly correlated with SOM.Conclusions
Our findings indicated that the single- and multi-fractal parameters adequately described the scaling properties of the soil PSD and the influences of soil structure and soil nutrients for the different land-use patterns in the Yellow River Delta Wetland of China. 相似文献10.
Jesús M. Marín-Benito M. Soledad Andrades M. Sonia Rodríguez-Cruz María J. Sánchez-Martín 《Journal of Soils and Sediments》2012,12(7):1111-1123
Purpose
The aim of this work was to study the temporal changes in the sorption?Cdesorption of fungicides in a sandy clay loam soil amended with spent mushroom substrate (SMS) under controlled laboratory conditions and the influence that fungicides properties and soil characteristics have on these processes. Soil amendment with SMS is becoming a widespread management practice since it can effectively solve the problems of uncontrolled SMS accumulation and disposal and improve soil quality. However, when simultaneously applied with pesticides, SMS can significantly modify the environmental behaviour of these compounds.Materials and methods
Sorption?Cdesorption isotherms of metalaxyl, penconazole, pyrimethanil and iprovalicarb for unamended and amended vineyard soils from La Rioja (Spain) were obtained. Composted SMS (C-SMS) and fresh SMS (F-SMS) from cultivation of different mushrooms were used as amendments at 2?% and 10?% rates. Soil parameters (organic carbon (OC), dissolved organic carbon (DOC), humic acid (HA) and fulvic acid (FA)) and sorption (Kf, nf, Kd, Koc) and desorption (Kfd, nfd, H) parameters of fungicides were determined over 0, 6 and 12?months of soil incubation with SMS under controlled conditions.Results and discussion
Addition of amendments to soil increased soil sorption capacity of fungicides. Kd values increased with the hydrophobic character of fungicides (metalaxyl?<?iprovalicarb?<?pyrimethanil?<?penconazole) at both amendment rates. The lower content of DOC and the higher degree of OC humification enhanced sorption of all fungicides by the soil?+?C-SMS with regard to the soil?+?F-SMS. In general, sorption of fungicides decreased after 6 and 12?months of soil?+?SMS incubation, although the humification degree of the remaining OC expressed by HA/FA increased. This might indicate that the OC content was more important for fungicide sorption than the changes in its nature with the incubation time. SMS addition favoured desorption of metalaxyl and iprovalicarb, in general, whereas irreversible sorption of penconazole and pyrimethanil increased. However, the opposite trends were observed when the soil?+ SMS incubation time increased.Conclusions
The results show an increase in sorption of all fungicides by amending soil with composted or fresh SMS. However, desorption of fungicides increases or decreases depending on the properties of fungicides and soil?+ SMS. Changes in both processes with the incubation time are more related to the OC content of the amended soil than to the evolution of its nature. These outcomes are of interest for extending SMS application to soil with minimal or no environmental risk when used simultaneously with fungicides. 相似文献11.
Anastasia Shchegolikhina Stephan Schulz Bernd Marschner 《Journal of Soils and Sediments》2012,12(8):1280-1291
Purpose
The structure and properties of the soil organic matter and its interactions with solutes may be altered by changes in soil chemistry and by the aging of soil. The main objective of this study was to investigate the effect of long-term aging and cation saturation of soil on the extractability and degradability of two hydrophobic xenobiotics in soil. In addition, it was tested if drying or freezing of soils can accelerate the relevant aging processes.Materials and methods
The sandy topsoil was treated by either 0.1?M NaCl, CaCl2, AlCl3 solutions or water and samples were sterilized by ??-radiation and spiked with 14C-labeled nonylphenol (NP) or phenanthrene (Phe) at 10???g?g?1 of soil. Samples were then used in four parallel experimental setups: (1) 9?months of aging under sterile conditions, (2) inoculation by native original soil with further 7?months of aging (bioaging), (3) drying and wetting or (4) freezing and thawing of soils. After different time intervals, the extractability of xenobiotics with water, cyclodextrin, and ethanol was investigated.Results and discussion
During 9?months of aging under sterile conditions a continuous decrease of NP and Phe extractability and an increase of the non-extractable fraction occurred. During the 7?months of biologically active aging, the mineralization of NP was lower than of Phe while more NP remained extractable than Phe. In comparison to the sterile aging, the bioaging led to a less formation of non-extractable residues of NP and Phe. The long-term sterile aging effects on NP-extractability were also achieved by short-term freezing and thawing of the soils, while aging of Phe was better mimicked by drying?Cwetting cycles. The effects of cation saturation of soils on xenobiotics extractability were less pronounced.Conclusions
Sterile aging, bioaging, freezing, and thawing facilitate the formation of the non-extractable fraction of NP and Phe in the soils. Different cation treatments alter soil properties, but the effects on aging of NP and Phe in soils were negligible. 相似文献12.
Purpose
Sorption and desorption of butachlor were simultaneously investigated on synthesized pure amorphous hydrated Fe oxides (AHOs Fe), and soils both with and without surface coating of AHOs Fe, with special interest towards how amorphous sesquioxides affect and contribute to butachlor retention in soils.Materials and methods
The AHOs Fe was artificially synthesized pure materials. Two soils with contrasting physicochemical properties selected for study were black soil and latosol, belonging to permanent charged soil and variable charged soil, respectively. Both soils were further treated using AHOs Fe for detecting the differentiation from native soils regarding butachlor retention produced after the soils were surface-coated by AHOs Fe. A sorption experiment was conducted using a batch equilibrium technique, and desorption was carried out immediately following sorption by three sequential dilution. Hysteresis index (HI) values were calculated to investigate desorption hysteresis by developing desorption isotherms concentration dependent and time dependent, respectively.Results and discussion
The sorption capacity for butachlor increased in the order of AHOs Fe, uncoated soils, and soils with surface coating of AHOs Fe. The sorption capacity of both soils significantly increased after surface coating by AHOs Fe (p?<?0.01), with a bigger increase achieved by black soil (52.0 %) as compared with that by latosol (45.3 %). Desorption of butachlor was coincidently hysteretic on AHOs Fe, and soils both uncoated and coated, whereas variation in desorption hysteresis was different between AHOs Fe and soils with increasing butachlor sorption loading, indicating different sorption mechanisms were operative for AHOs Fe and soils across the entire butachlor concentration range. Hysteresis of butachlor desorption was weakened after the soils were surface coated by AHOs Fe, as suggested by the changed HI values.Conclusions
With high specific surface area and highly reactive surfaces, the “active” AHOs Fe originally has a relatively high sorption capacity and affinity for butachlor. While in natural soils, where the inevitable association derived from soil organic matter (SOM) would restrain AHOs Fe from sequestrating butachlor directly, AHOs Fe may likely contribute in a mediator way by coordinating active sites both on and within SOM. This may enhance the availability of sorption domains both on and within soils, thereby achieved an enhanced but more reversible retention for butachlor in soils after their surfaces were coated by AHOs Fe. This study has extended the observations of the role of noncrystalline sesquioxides in retention of pesticides such as butachlor from pure clay mineral systems to natural soils. 相似文献13.
Sorption isotherms and kinetics of Sb(V) on several Chinese soils with different physicochemical properties 总被引：1，自引：0，他引：1
Jian-Xin Fan Yu-Jun Wang Xiao-Dan Cui Dong-Mei Zhou 《Journal of Soils and Sediments》2013,13(2):344-353
Purpose
Sorption of antimony on soils is the primary factor that influences its immobilization and migration in the environment. In the present study, the sorption of Sb(V) onto seven Chinese soils with different physicochemical properties was investigated for exploring the relationship between the sorption capacity of Sb(V) and the physicochemical properties of the soils.Materials and methods
Sorption isotherms and kinetics experiments were performed to ascertain the sorption capacity and the kinetic rate, respectively. The relationship between the sorption capacity of Sb(V) and the physicochemical properties of the soils was analyzed by multiple linear regressions.Results and discussion
The results showed that the sorption isotherms fitted with both the Langmuir and Freundlich equations very well (R 2?=?0.936–0.997), and the sorption kinetic of Sb(V) onto the seven Chinese soils followed a pseudo-second-order reaction. The maximum sorption capacity of Sb(V) on the soils ranged from 134 to 1,333 mg?kg?1. Nearly 94 % of the variability in maximum sorption of Sb(V) modeled by Freundlich equation could be described by FeDCB (dithionite–citrate–bicarbonicum extractable), and nearly 98 % of the variability could be described by FeDCB and AlDCB.Conclusions
Multiple linear regressions can be successfully applied to analyzing the relationship between sorption capacity and soil properties. FeDCB and AlDCB played important roles in Sb(V) sorption onto soils. It would be useful to understand the environmental behaviors of Sb and for the implementation of risk assessment management and remediation strategies of Sb. 相似文献14.
Effects of biochars derived from different feedstocks and pyrolysis temperatures on soil physical and hydraulic properties 总被引：1，自引：1，他引：0
Purpose
Biochar addition to soils potentially affects various soil properties, and these effects are dependent on biochars derived from different feedstock materials and pyrolysis processes. The objective of this study was to investigate the effects of amendment of different biochars on soil physical and hydraulic properties.Materials and methods
Biochars were produced with dairy manure and woodchip at temperatures of 300, 500, and 700 °C, respectively. Each biochar was mixed at 5 % (w/w) with a forest soil, and the mixture was incubated for 180 days, during which soil physical and hydraulic properties were measured.Results and discussion
Results showed that the biochar addition significantly enhanced the formation of soil macroaggregates at the early incubation time. The biochar application significantly reduced soil bulk density, increased the amount of soil organic matter, and stimulated microbial activity at the early incubation stage. Saturated hydraulic conductivities of the soil with biochars, especially produced at high pyrolysis temperature, were higher than those without biochars on the sampling days. The treatments with woodchip biochars resulted in higher saturated hydraulic conductivities than the dairy manure biochar treatments. Biochar applications improved water retention capacity, with stronger effects by biochars produced at higher pyrolysis temperatures. At the same suction, the soil with woodchip biochars possessed higher water content than that with the dairy manure biochars.Conclusions
Biochar addition significantly affected the soil physical and hydraulic properties. The effects were different with biochars derived from different feedstock materials and pyrolysis temperatures. 相似文献15.
Elsayed A. Elkhatib Ahmed M. Mahdy Mohamed M. ElManeah 《Journal of Soils and Sediments》2013,13(1):94-105
Purpose
Recent research has focused on using water treatment residuals (WTRs) as cost-effective materials to remove potential environmental contaminants. To better understand and predict how WTRs affect the mobility and retention of nickel (Ni) in soils with time, it is crucial that the kinetics and thermodynamics of these reactions be understood. Such information is lacking in the literature and would aid in evaluating the suitability of WTR as a soil amendment for adsorbing Ni contaminant. Accordingly, we focused on investigating the retention of Ni in differing soils and the subsequent influence of WTR application on Ni retention.Materials and methods
To examine the effects of WTR application on the characteristics of Ni retention, equilibrium, and kinetics, sorption batch experiments were performed on three soils having different properties. The sorption data were applied to the first-order kinetic model, and the Arrhenius equation was used to determine the thermodynamic parameters.Results and discussion
The quantity of Ni sorbed by the soils followed the trend Typic Torrifluvent > Typic Calciorthids > Typic Torripsamment. Soil sorption isotherms shift toward a higher sorption of Ni indicating addition of more sorption sites as a result of WTRs’ application. Data generated at different temperatures for soils and WTR-amended soils fitted well to Freundlich isotherm and first-order kinetic models. The energy of activation (E a) and enthalpy (ΔH #), entropy (ΔS #), and free energy of activation (ΔG #) related to Ni sorption were calculated using the Arrhenius equation. The activation energy (E a) values (51.65–130.0 kJ mol?1) and the positive ΔH # values characterize Ni sorption process onto the sorbents studied as chemisorption with an endothermic nature. The large negative ΔS # values (?262 to ?290 J?mol?1) and the large positive ΔG # values (88.11–89.14 kJ mol?1) indicate the involvement of an associative mechanism in the Ni sorption process.Conclusions
WTR addition has led to an overall increase in Ni sorption by the amended soils. Such increase in Ni sorption provides evidence that WTR has the potential for land application as a Ni sorbent in soil remediation techniques. The sorption capacity of the soils and WTR-amended soils enhanced with an increase in temperature. Therefore, to truly understand the potential fate and mobility of Ni in the natural environment, temperature, in particular, should be considered. 相似文献16.
Purpose
Cover crop residue is generally applied to improve soil quality and crop productivity. Improved understanding of dynamics of soil extractable organic carbon (EOC) and nitrogen (EON) under cover crops is useful for developing effective agronomic management and nitrogen (N) fertilization strategies.Materials and methods
Dynamics of soil extractable inorganic and organic carbon (C) and N pools were investigated under six cover crop treatments, which included two legume crops (capello woolly pod vetch and field pea), three non-legume crops (wheat, Saia oat and Indian mustard), and a nil-crop control (CK) in southeastern Australia. Cover crops at anthesis were crimp-rolled onto the soil surface in October 2009. Soil and crop residue samples were taken over the periods October?CDecember (2009) and March?CMay (2010), respectively, to examine remaining crop residue biomass, soil NH4 +?N and NO3 ??CN as well as EOC and EON concentrations using extraction methods of 2?M KCl and hot water. Additionally, soil net N mineralization rates were measured for soil samples collected in May 2010.Results and discussion
The CK treatment had the highest soil inorganic N (NH4 +?N?+?NO3 ??CN) at the sampling time in December 2009 but decreased greatly with sampling time. The cover crop treatments had greater soil EOC and EON concentrations than the CK treatment. However, no significant differences in soil NH4 +?N, NO3 ??CN, EOC, EON, and ratios of EOC to EON were found between the legume and non-legume cover crop treatments across the sampling times, which were supported by the similar results of soil net N mineralization rates among the treatments. Stepwise multiple regression analyses indicated that soil EOC in the hot water extracts was mainly affected by soil total C (R 2?=?0.654, P?<?0.001), while the crop residue biomass determined soil EON in the hot water extracts (R 2?=?0.591, P?<?0.001).Conclusions
The cover crop treatments had lower loss of soil inorganic N compared with the CK treatment across the sampling times. The legume and non-legume cover crop treatments did not significantly differ in soil EOC and EON pools across the sampling times. In addition, the decomposition of cover crop residues had more influence on soil EON than the decomposition of soil organic matter (SOM), which indicated less N fertilization under cover crop residues. On the other hand, the decomposition of SOM exerted more influence on soil EOC across the sampling times among the treatments, implying different C and N cycling under cover crops. 相似文献17.
Soil organic matter evolution after the application of high doses of organic amendments in a Mediterranean calcareous soil 总被引：1，自引：0，他引：1
Sergio González-Ubierna Ignacio Jorge-Mardomingo Beatriz Carrero-González María Teresa de la Cruz Miguel ángel Casermeiro 《Journal of Soils and Sediments》2012,12(8):1257-1268
Purpose
We investigate the coevolution of soil organic matter (SOM) and soil properties in a semiarid Mediterranean agroecosystem, as well as the 1-year evolution of the different pools of soil organic and inorganic carbon and their influence on soil respiration after the application of a single high dose of three different organic amendments.Material and methods
We applied a single high dose (160?Mg?ha?1 in dry weight (DW)) of three types of organic amendments: aerobically digested sewage sludge (AE), anaerobically digested sewage sludge (AN), and municipal solid waste compost (MSWC), in a calcareous Mediterranean soil. The study area is located in the southeast of Madrid (Spain), characterized by a Mediterranean climate with a marked seasonal and daily contrast. We analyzed different forms of soil organic and inorganic carbon and soil respiration rates. The measurements have been performed quarterly for 1?year.Results and discussion
The results showed that the coevolution of SOM and soil largely depends on the origin and composition of the organic amendments used. The AN sludge affected the soil chemistry more. The organic matter (OM) provided by AE treatments underwent more intense mineralization processes than AN, with the OM from MSWC being more stable. This behavior could be explained by the different pools of carbon involved in each case. The treatments contributed differently to soil respiration rates following the sequence: AE > AN > MSWC. The application of organic amendments in calcareous Mediterranean soils also modified the inorganic carbon pools.Conclusions
SOM and soil coevolution after organic amendments application depends on the origin and chemical composition of the inputs. The decision-making process of urban organic waste application with regard to agricultural policy must take into account the different behavior in soil of the different types of amendments. 相似文献18.
Qingfeng Meng Jingsong Yang Rongjiang Yao Guangming Liu 《Journal of Soils and Sediments》2013,13(4):664-676
Purpose
The impacts of different land use practices on soil quality were assessed by measuring soil attributes and using factor analysis in coastal tidal lands. The study provided relevant references for coastal exploitation, land management and related researches in other countries and regions.Materials and methods
Measured soil attributes include physical indicators [bulk density (ρ b), total porosity (? t) and water-holding capacity (WHC)], chemical indicators [pH, electrical conductivity (EC), total nitrogen (TN), soil organic matter (SOM), available N, available P and available K] and biological indicators (urease activity, catalase activity and phosphatase activity), and 60 soil samples were collected within five land use types [(1) intertidal soils, (2) reclaimed tidal flat soils, (3) farmland soils, (4) suburban vegetable soils, (5) industrial area soils) in Jianggang village of Dongtai county, Jiangsu province of China.Results and discussion
The results from the investigation indicated that selected soil properties reduced to three factors for 0–20-cm soil depth; “Soil fertility status” (factor 1), “Soil physical status” (factor 2) and “Soil salinity status” (factor 3). For the first factor, the measured soil attributes with higher loadings were TN and SOM, which represented soil fertility feature, and for the second and third factors, the measured soil attributes with higher loadings were ρ b and available K as well as EC, which reflected soil physical properties and soil salinity feature, respectively.Conclusions
Changes in different land use types due to plants (corn, wheat and green vegetable) and application of fertilizers were characterized by promoted soil quality, including improvements in chemical properties (increasing SOM concentration, TN and nutrient available to plants; decreasing EC), improvements in soil physical properties (decreasing ρ b; increasing ? t and WHC) and enhancements in soil enzyme activities. Judging from the soil quality indices, the soil quality was affected by different land use practices and decreased in sequence of suburban vegetable soils, farmland soils, industrial area soils, reclaimed tidal flat soils and intertidal soils in the study area. 相似文献19.
Michał Ćwiąkała Urszula Kołodziejczyk Leszek Rafalski 《Journal of Soils and Sediments》2013,13(1):64-71
Purpose
Winter road maintenance involves the use of various chemical compounds which affect the active capillarity of soils. The main goal of the study was to determine a model to predict changes in the active capillarity of soils using distilled water and water solutions of chemical compounds which are used in winter road maintenance. The purpose of the first part of the experiment was to determine a model to predict changes in the height of capillarity rise and the rate of capillary rise with time. The second part of the experiment investigated how water solutions of selected chemical compounds altered the soils’ active capillarity as determined using distilled water.Materials and methods
The research was carried out on three soils from deposits in west-central Poland, and their separated fractions. Active capillarity was investigated with the use of distilled water and 5 and 10 % solutions of ten chemical compounds used in winter road maintenance. The rate and height of capillary rise were measured in transparent vertical tubes, placed vertically in a glass tank into which the distilled water or solutions of chemical compounds were poured.Results and discussion
The rate of capillary rise was decreasing as a function of time. After the first part of the experiment had been completed, an analysis was made of the statistical fit between the experimental data for capillary rise of distilled water in the studied soils and soil fractions, and the model described by the formula $ h(t) = {h_1} + {v_1} \times ln(t) $ , where h 1 denoted the height of capillary rise in the first second, v 1 denoted the rate of capillary rise, and t denoted time. High determination coefficients indicated a good fit of the model to the experimental data. In the second part of the study, it was found that solutions of chemical compounds caused a reduction in the active capillarity of the studied soils relative to the capillarity determined using distilled water. It was possible to determine a capillarity coefficient w k so as to compare the capillary rises in soil of distilled water and of the various chemical compounds in 5 and 10 % solution. Analysis of the results showed that the capillarity coefficient w k is a characteristic feature which depends on the type and concentration of the chemical subject to capillary action and on the type and fraction of soil.Conclusions
The active capillarity of soil depends on the type and concentration of the capillary fluid such as distilled water or water solutions of chemical compounds used in winter road maintenance and other factors. The relation between the height of capillary rise h and time t can be described using the formula $ h(t) = {h_1} + {v_1} \times \ln (t) $ . The water solutions of chemical compounds used in winter road maintenance caused a reduction in the active capillarity of the studied soils relative to the capillarity determined using distilled water. It was found that the susceptibility of soil to capillary rise can be determined based on the capillarity coefficient w k . This coefficient depends on the type and concentration of the chemical compound in the soil and on the soil type and fraction. The effect of these factors can be accounted for using the formula $ h(t) = {w_k} \times {h_1} + {w_k} \times {v_1} \times ln(t) $ . 相似文献20.
Sang-Sun Lim Woo-Jung Choi Kwang-Seung Lee Hee-Myong Ro 《Journal of Soils and Sediments》2012,12(9):1299-1308