小麦秸秆生物炭对石油烃污染土壤的修复作用

以小麦秸秆为原材料,在300℃下缺氧裂解3、6、8 h制备生物炭,比较了3种生物炭的产率、pH值、灰分以及C、H、N元素含量,表征了300℃、6 h生物炭的表面形态,并用其作为修复材料,对大港油田的石油污染土壤进行修复。结果表明,随裂解时间的延长,生物炭产率下降,pH值升高,灰分含量增加,H/C值下降,但产率、pH值、灰分和H/C值都是从3 h到6 h差异显著,6 h到8 h差异不显著。C元素含量先升高后下降。石油污染土壤经生物炭修复14 d和28d后,总石油烃降解率分别为45.48%和46.88%,均显著高于对照组。修复14 d后土壤中的萘、苊、苯并[a]蒽、屈、苯并[b]荧蒽、苯并[k]荧蒽、苯并[a]芘、茚并[1,2,3-cd]芘也都有不同程度的下降,其中苯并[a]芘含量下降幅度达98.18%,其他几种PAH的降解率也都高于对照组,28 d后这些PAH的含量又有上升趋势。这说明小麦秸秆裂解时间对生物炭的性质有影响;300℃、6h生物炭可以用来修复石油污染的土壤。     

生物炭修复重金属污染农田土壤的机制及应用研究进展

将生物质转化为生物炭并用于重金属污染农田土壤修复中,是有效利用生物质资源、保障粮食安全的有效途径之一。然而,生物炭的应用效率受其特性和土壤环境影响极大。该研究综述了生物炭特性,并探讨了生物质和热解温度对其影响规律,阐明了生物炭对重金属的直接固定作用,以及通过影响土壤pH值、阳离子交换量（Cation Exchange Capacity,CEC）、矿物组分和有机质等,进而间接固定重金属的作用机制。同时,该文系统总结了国内外生物炭在田间试验中的应用,从土壤重金属迁移性和生物有效性、作物累积重金属和作物产量等3个方面阐明了生物炭的应用效果和作用规律。针对田间试验条件区别于室内试验的特殊性,探讨了生物炭施撒方式及用量、施肥等田间管理和气候环境等现场条件对生物炭应用的影响,并对今后完善生物炭在土壤修复中作用机制、扩大研究尺度和长期土壤监测等方面研究进行了展望。     

生物炭复配矿物质钝化修复重金属复合污染土壤的研究

选取稻壳生物炭、木屑生物炭、羟基磷灰石及蒙脱石作为钝化材料,按钝化剂5:土壤100的重量比添加到重金属复合污染土壤中,通过测定土壤重金属形态变化,研究了钝化材料修复重金属复合污染土壤的效果及其机理。结果表明:生物炭和矿物质均能有效固定土壤中重金属,其中羟基磷灰石的钝化效果最好,对土壤镉、铜和铅的固定化率分别为76.24%、74.26%和98.13%。蒙脱石的钝化效果最差。添加钝化剂后土壤重金属中的酸可提取态和可还原态向着更加稳定的可氧化态和残渣态转化,土壤重金属活性态比例下降。生物炭复配矿物质处理对土壤重金属的钝化效果介于单一生物炭处理和单一矿物质处理之间。此外,生物炭及矿物质均能有效地提高土壤pH,pH可能是影响土壤修复效果的关键因素。     

大豆秸秆生物炭对铅锌尾矿污染土壤的修复作用

采用盆栽空心菜的方法,研究了大豆桔杆生物炭对铅锌尾矿污染土壤的修复作用。污染土壤中Cu、Zn、Pb和Cd含量分别为50,400,1 119,3.4mg/kg。结果表明:土壤无论是否受到铅锌尾矿污染,添加3%生物炭(w/w)均能显著提高土壤pH;3%生物炭能够抑制铅锌尾矿污染导致的土壤pH降低。大豆桔杆生物炭对尾矿污染土壤和未污染土壤中重金属有效态的影响不同,与未污染土壤相比,3%生物炭的钝化作用不能抵消铅锌尾矿污染导致的重金属有效态含量的增加。铅锌尾矿污染抑制空心菜生长;施加3%生物炭可以消除铅锌尾矿污染对空心菜生长的抑制作用。生物炭显著降低污染土壤空心菜根部重金属含量,而对地上部分的影响,不同元素表现出不同的特点;3%生物炭能够阻控铅锌尾矿污染土壤中Cu、Zn、Pb和Cd向空心菜地上部迁移富集。大豆桔杆生物炭对空心菜吸收重金属的影响,在铅锌尾矿污染土壤和未污染土壤上表现不同,存在元素之间的拮抗作用以及由于生物炭提高空心菜生物量所产生的稀释作用。在研究设置条件下,与未污染土壤相比,从空心菜生物量和可食部分吸收重金属含量来评价,施加3%大豆桔杆生物炭可以修复铅锌尾矿导致的土壤污染。     

生物质炭修复有机物污染土壤的研究进展

生物质炭由于其特殊的多孔性结构、强的吸附性能,以及富含多种营养元素和特殊官能团等特点,成为近年来在农业应用和环境污染治理方面的热点。本文介绍了生物质炭的基本特性,提出生物质炭可能在今后成为活性炭的替代品;综述了生物质炭在修复有机物(石油烃、有机农药、PAHs、PCBs)污染土壤中的研究进展,并探讨了生物质炭应用于污染土壤修复的环境风险。生物质炭在修复有机物污染土壤方面有巨大的潜力,但在大规模应用之前还需要做长期深入的研究。     

两种生物炭对污染土壤铜有效性的影响

采用盆栽试验,探究了添加不同比例(0,1%,2%,4%)玉米秸秆炭和商陆根生物炭对铜污染红壤中小油菜生长与铜有效性的影响。结果表明,与对照相比,添加两种生物炭均能够增加铜污染红壤上小油菜的生物量。在低铜污染水平下,4%玉米炭和商陆炭处理小油菜生物量分别增加了21.2倍和67.9倍;高铜污染水平下,4%玉米炭和商陆炭处理小油菜生物量分别增加了8.6倍和109.6倍。商陆炭的添加能够显著提高土壤p H值,在低铜污染水平下,商陆炭处理土壤p H值升高了0.4~1.66个单位,较玉米炭处理土壤p H值多升高了0.25~1.35个单位;在高铜污染下,商陆炭处理土壤p H值升高了0.33~1.52个单位,较玉米炭土壤p H值多升高了0.3~1.25个单位。向污染土壤中添加两种生物炭均能够显著降低土壤有效态铜的含量。其中,在低铜污染土壤中,4%玉米炭和商陆炭处理土壤有效态铜含量分别降低了21.9%和45.2%;在高铜污染土壤中,4%玉米炭和商陆炭处理土壤有效态铜含量分别降低了41.9%和53.8%。两种生物炭均能够显著降低小油菜铜累积量,向低铜污染土壤中添加4%的玉米炭和商陆炭,小油菜地上部铜含量下降了21.2%、67.8%。高污染土壤中添加4%的玉米炭和商陆炭小油菜地上部铜含量下降了19.9%、66.8%。两种生物炭均可以改良红壤的酸度,降低土壤铜有效性,并提高小油菜的生物量,降低小油菜铜累积量,但是商陆炭的效果更为明显。     

工业废弃物对土壤的污染与防治

近几十年来,人类研究的许多问题中,防止污染,保护环境的问题具的特别重要的意义。据统计,40亿现代人对自然的这种影响,相当于石器时代300-400亿人的影响。这个问题已超越了国家民族的界限,具有全球的特征。科学技术进步的蓬勃发展,使每年排入地球大气中的毒气和尘埃达10-100亿吨,排入世界水体中的工业废水约6000亿吨,中和这些废水需要12-15倍的清洁水。     

生物有机肥和生物炭对Cd和Pb污染稻田土壤修复的研究

在田间试验条件下,研究施用生物有机肥和生物炭对稻田Cd和Pb污染的钝化修复效果。研究结果表明:施用生物有机肥和生物炭处理可以提高土壤p H值以及土壤养分含量,并显著降低土壤有效态Cd和Pb的含量,且土壤p H值与土壤有效态Cd和Pb的含量呈极显著负相关;生物有机肥和生物炭处理还可以降低水稻体内Cd和Pb的含量,其中水稻糙米Cd降幅达到了22.00%和18.34%,水稻糙米Pb含量的降幅也达到了33.46%和12.31%,且水稻糙米Cd和Pb的含量与土壤有效态Cd和Pb的含量呈显著正相关。综合各处理对土壤p H值、土壤养分含量、土壤有效态Cd和Pb的含量以及水稻Cd和Pb的影响,可以看出生物有机肥和生物炭处理对于Cd和Pb污染稻田土壤有较好的修复效果。     

含磷材料及生物炭对复合重金属污染土壤修复效果与修复机理

选取含磷材料（胛）、牛粪生物炭（DM）和水稻秸秆生物炭（Rs）实施Pb、Zn、Cd复合污染土壤化学稳定修复,进而评价修复效果,并分析影响因素;借助BCR连续提取法和x射线衍射光谱（XRD）探讨可能存在的修复机理。经过56d的化学稳定修复,修复材料均能显著降低TCLP提取态Pb、zn、cd,修复效果均为：Pb〉Zn〉Cd。三种修复材料对Pb、cd的修复效果为Er〉DM〉RS,对zn的修复效果基本相同。胛处理使土壤TCLP提取态的Pb、zn、cd分别降低了77．6％、31．5％、27．9％;DM处理使TCLP提取态的Pb、zn、cd分别降低了56．0％、26．1％、10．O％;RS处理使TCLP提取态的Pb、zn、cd分别降低了35．8％,25．0％和4．4％。三种修复材料均可促进Pb、cd从不稳定态向稳定状态转化。胛对Ph的固定机理主要是溶解一沉淀,XRD证明有Ca2Pb8（PO4）6（OH）2和Pb10（PO4）6（OH）2沉淀生成;DM固定Pb包括沉淀、吸附、离子交换等,XRD证明有Ca2Pb8（PO4）6（OH）2生成;Rs固定Pb主要为吸附、离子交换。研究结果表明,含磷材料和牛粪生物炭可作为理想的土壤Pb、zn、cd的修复材料。     

砷污染土壤的生物修复研究进展

土壤As污染已是全球性问题,我国也不例外,对As污染土壤的生物修复已是研究热点,但相关机理仍不完全清楚.本文综述了国内外微生物、蚯蚓、植物在As污染土壤中吸收转化As及其解As毒机理,以及微生物-植物复合系统修复As污染土壤方面实验室内研究情况.目前广泛认为植物修复土壤重金属/非金属污染较有应用前景,可限于甚至是使用超富集植物单一作用下仍有较多缺陷,如通过微生物技术及蚯蚓调节根际微生态,以利于植物在污染土壤中存活或/和吸收更多的As,将极具应用前景.     

Environmental impacts of surface mining on mined lands,affected streams and agricultural lands in the Dabaoshan Mine region,southern China

Impacts of surface mining on ecosystems were investigated in the Guangdong Dabaoshan Mine region, southern China. Significant soil acidification has been induced by mining activities which cause oxidation of metal sulfides contained in the mine spoils. Natural colonization of vegetation in the mine site has been impeded and this has resulted in severe soil erosion. Acid mine drainage from this mine site has caused the degradation of the downstream aquatic ecosystems. Mine water with pH< 3·5 has been continuously flowing into a first‐order tributary of the Beijiang River and has destroyed all the aquatic life to a distance of at least 25 km downstream of the discharge point, even when the pH rose to above 6 in the Hengshishui River (a third‐order tributary of the Beijiang River). Further downstream, macroinvertebrates first occurred at about 30 km from the discharge point, and only one species was found. This is in contrast to a reference site that was not affected by acid mine drainage, where 36 macroinvertebrate taxa were found. Acidic mine water also had marked impacts on the agricultural lands irrigated with it. Severe contamination of the soils by mine drainage is responsible for the extremely high concentrations of some heavy metals in the edible portions of a variety of food crops grown on the agricultural lands. Copyright © 2005 John Wiley & Sons, Ltd.     

Behaviour and assessment of bioavailability of organic contaminants in soil: relevance for risk assessment and remediation

Abstract. Soils contaminated with organic chemicals are now widespread in industrialized and developing countries, and the risk assessment and remediation of such contaminated sites is a priority. However, containment and remediation strategies are complicated in many cases by the range of contaminants present and the historical nature of the contamination. Research has increased our understanding of the behaviour of organic contaminants in soil and the factors that control their behaviour. There is a fundamental need to understand and, where possible, quantify the bioavailable fraction as well as the total concentration of contaminant present in soil: the bioavailable fraction is key to toxicity or biodegradation. To quantify these fractions, a large number of techniques have been employed, ranging from organic and aqueous based solvent extractions to the use of biota. Many studies have been carried out investigating the use of chemical techniques to describe bioavailability, which could be used in the assessment and remediation of contaminated land. The aim of this review is to consider the behaviour of organic contaminants in soil, highlighting issues of bioavailability, and then to discuss the relevance of the various methods for assessing risk and potential remediation of organic contaminants in soil.     

Metal contamination from open-cast copper and sulphur mining in southeast Ireland

The metal content was determined in soil and vegetation around the eastern zone of the disused sulphur and copper mines at Avoca (southeast Ireland). A 250 m × 250 m grid survey was conducted covering a total area of 4 km². The mining belt was in the centre of the investigated site and was sampled separately. Iron, Zn, Cu and Cd concentrations in soil and plant material were determined, in addition to soil organic matter content and soil pH. Soil samples taken from the spoil showed elevated Cu and Cd concentrations, and low soil pH and organic matter content. At least 50 per cent of the agricultural sites examined around the East Avoca Mine showed elevated soil Cu and Cd concentrations, whereas Zn and Fe soil concentrations were within the range for unpolluted soils. None of the vegetation analysed had elevated Zn, Cd, Fe or Cu concentrations. Overall there was no indication of serious metal contamination in either soils or vegetation surrounding the mine in spite of extensive dust deposition during open-pit mining activity 15–30 years ago. However, a plume of elevated Cu in the soil was identified, which originated from a large spoil heap and had been spread for some 2·0 km by the prevailing wind.     

Coastal land scalding in NSW,Australia: soil chemical characteristics and their implications for remediation of the scalded lands

Scalded lands are common in acid sulphate soil areas on the New South Wales coast, Australia. In this work, chemical characteristics of the scalded acid sulphate soils at nine sites along this coast were investigated. The investigated acid sulphate scalds are characterized by an extremely acidified topsoil layer (0–0.6 m) although they derive from the sediments of varying salinity and the metal sulphides contained in the soils have experienced different degrees of oxidation. Almost all of the investigated scalds occur in the areas that have a lower surface elevation than the surrounding areas. These hollows may act as sinks for acid sulphate materials and salts that are transported from the surrounding areas and the shallower watertables in such locations may enhance upward transport of acid and salt materials from the underlying oxidized sulphidic sediments. In general, the scalded acid sulphate soils have less organic matter and soluble phosphorus, and a greater salinity, soluble acidity, soluble Al, Mn and Zn concentrations, compared to the adjacent non‐scalded acid sulphate soils. These are most likely soil constraints for revegetation of the scalded lands and treatment will need to involve acid neutralization (e.g. application of lime) and addition of P fertilizers to reduce the soluble acidity, immobilize soluble Al, Mn and Zn, and increase P availability. The evidence also shows that the higher soluble Al concentration in the scalded soils, relative to the non‐scalded soils, is related to their lower organic matter content. Hence, rehabilitation of these scalded lands should involve the addition of organic matter to reduce soluble Al concentrations; it may also help reduce Mn and Zn toxicity, and salinity. Copyright © 2001 John Wiley & Sons, Ltd.     

Farmer perception of soil erosion and investment in soil conservation measures: emerging evidence from northern Taraba State,Nigeria

To combat soil erosion in the northern part of Taraba State, Nigeria, farmers are of major importance. Their perceptions vitally influence the levels of support and investment associated with solving problems of soil erosion through adoption of practices that are alternative to those in current use, including approaches focused on soil conservation. The objective of this study was to evaluate how farmer perceptions of soil erosion influence their investments in soil conservation, particularly soil or stone bunds, their applications of organic amendments and inorganic fertilizers and other soil conservation practices. In the study area, we undertook a field plot experiment and carried out a survey, using open‐ and closed‐ended questions. Water erosion and depletion of fertility were taken as the main indicators of soil erosion. The results of the experiment showed that farmers were aware of and perceived both indicators as having increased over the past decade. Farmer investments in water erosion control (3.7 US$/ha) and the prevention of soil fertility depletion (37.8 US$/ha) in the study area were found to be limited. The results also showed that awareness of water erosion was only marginally correlated with investment in water erosion control (χ² = 4.906, P = 0.09) and not associated with investments in soil fertility control measures (χ² = 0.175, P = 0.92). Those farmers who identified depletion of soil fertility as a problem, based on erosion, were not significantly more likely to make greater investments in soil conservation (χ² = 0.947, P = 0.62) but did invest more in fertility measures (χ² = 3.199, P = 0.20). Hence, further research is needed to determine other factors that may influence farmer investment in soil conservation, especially factors related to socio‐economic characteristics of farm households, institutional and technological innovations and field characteristics that were not addressed in this study.     

Use of organic amendment as a strategy for saline soil remediation: Influence on the physical, chemical and biological properties of soil

The effectiveness of adding two organic wastes (cotton gin crushed compost, CGCC, and poultry manure, PM) to a saline soil (Salorthidic Fluvaquent) in dryland conditions near Seville (Guadalquivir Valley, Andalusia, Spain) was studied during a period of 5 years. Organic wastes were applied at rates of 5 and 10 t organic matter ha⁻¹. One year after the assay began, spontaneous vegetation had appeared in the treated plots, particularly in that receiving a high PM dose. After 5 years the plant cover in this treated plot was around 80% (compared with the 8% of the control soil). The effect on the soils physical and chemical properties, soil microbial biomass, and six soil enzymatic activities (dehydrogenase, urease, protease, β-glucosidase, arylsulfatase, and phosphatase activities) were ascertained. Both added organic wastes had a positive effect on the physical, chemical and biological properties of the soil, although at the end of the experimental period, the soil physical properties, such as bulk density, increased more significantly in the CGCC-amended soils (23%) and the exchangeable sodium percentage (ESP) decreased more significantly in the CGCC-amended soils (50%) compared to the unamended soil. Water soluble carbohydrates and soil biochemical properties were higher in the PM-amended soils compared to the CGCC-amended soils (by 70% for water soluble carbohydrates, and by 34, 18, 37, 39, 40 and 30% for urease, protease, β-glucosidase, phosphatase, arylsulfatase and dehydrogenase activities, respectively). After 5 years, the percentage of plant cover was >50% in all treated plots and 8% in the control soil.     

长期石油污染土壤中胡敏酸的结构表征：热分析和软X射线近边吸收谱

对一口开采约20 年的废弃油井,在距离井口0.5、1.5、3.5、5.5和7.5 m处进行采样,采用差热-热重分析（(DTA-TGA）)和同步辐射软X射线近边吸收谱（(C-1s NEXAFS）)方法,研究了长期不同程度石油污染土壤中胡敏酸（(HA）)的结构特征。结果表明：随着与油井口距离的减小,HA的中温和高温放热峰的反应热及热失重增加,高温放热峰/中温放热峰比值增大;软X射线近边吸收谱显示,HA的芳香碳和羧基碳含量增加,脂族碳含量以及脂族碳/芳香碳比值下降。上述结果说明,随石油含量增加,HA的脂族性降低而芳香性增强。C-1s NEXAFS用于HA的结构表征是可行的,能够揭示出不同程度石油污染土壤中HA结构特征的变化规律。     

长期不同施肥对太湖地区黄泥土总有机碳及颗粒态有机碳含量及深度分布的影响

研究了长期不同施肥处理(化肥与秸秆配施、化肥与猪粪配施、单施化肥和不施肥)下,水稻土总有机碳和颗粒态有机碳的深度变化。结果表明,总有机碳(TOC)和颗粒态有机碳(POC)的深度分布都符合幂函数方程(Y=aX-b);不同的施肥处理主要影响耕层土壤的TOC和POC含量,POC分配比例在土壤深度上也有差异。其中,化肥与猪粪配施处理,由于有机物质的输入其TOC和POC含量显著高于其它3种处理;不施肥处理的POC含量显著高于单施化肥和秸秆配施化肥。并且,没有观察到耕层POC含量与不同小区的作物平均产量间的显著线性关系,这意味着土壤POC仅从含量来说,与作物生物量的输入并没有直接关系。而可能与施肥中的直接输入有较大关系。同时,POC含量与大团聚体颗粒组含量间的相关性不显著,说明不同施肥处理下POC的结构和性质可能发生了变异,导致其对大团聚体颗粒组形成及其稳定性的作用存在差异。可见,不同的施肥处理并没有改变TOC和POC的深度分布格局,只是改变了它们在耕层土壤的含量以及POC的分配比例。不同施肥处理下POC的结构性质及其稳定性的变化还有待于进一步的研究。     

基于景观功能的山区旅游公路水土保持设计思路——以湖北神农架木鱼坪至兴山县昭君桥旅游公路为例

为了充分发挥山区旅游公路水土保持措施的景观功能,以湖北神农架木鱼坪至兴山县昭君桥旅游公路为例,从景观美化功能和景观协调功能2方面进行水土保持设计。景观美化功能方面,根据项目沿线的自然、人文和公路本身的特点,分为3类景观特色带、3个景观过渡带和8个景观特色点,并配置相应的水土保持措施。景观协调功能方面,依据沿线的具体情况,使用渐缩式（阶梯式）空心砖护面墙、上挡墙L形种植槽、路基外侧悬墙式植槽和木桩栅栏式挡墙等绿化技术,进行公路沿线的绿化和美化。