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1.
以农林生物质为原材料,通过加入铁磁性助剂制备铁炭复合材料是农林生物质高值化利用和受污染水体及土壤治理的重要途径。铁炭复合材料具有高比表面积、丰富表面官能团和优异吸附性能,能够通过表面物理吸附和氧化还原作用,快速吸附污水中的重金属离子,并在外部磁场的吸引下实现快速分离回收和循环使用。该研究论述了不同制备方法的铁炭复合材料及其材料性能,对其去除有机染料污染物、治理污水和土壤重金属的研究现状及发展动态进行了分析和讨论。在此基础上,结合铁炭复合材料的结构发育机理和污水治理及土壤改良的产业发展现状,提出了兼顾低成本,易合成,高效益的复合材料制备方式建议,以期为其在环境污染治理中的广泛应用提供理论和实践参考,进而推动农林生物质资源化高值利用,助力生态环境的绿色低碳高质量发展。  相似文献   

2.
In this paper, reduced graphenoxide/attapulgite (rGO/APT)-supported nanoscale zero-valent iron (nZVI) composites (rGO/APT-nZVI) were synthesized to remove acid red 18 (AR18) and other organic dyes from aqueous solutions. The structure of synthetic rGO/APT-nZVI composite was characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), transmission electron microscope (TEM), and X-ray diffraction (XRD), and the removal properties of rGO/APT-nZVI on AR18 were investigated. The factors of various experimental parameters (ratio, pH, initial concentration, temperature, and time) impacting on removal of AR18 were studied as well. Comparison experiment of different materials showed that 93.5% of AR18 was removed using rGO/APT-nZVI, while only 7.9% and 64.8% of AR18 were removed using rGO/APT-nZVI after reacting for 30 min with an initial AR18 concentration of 100 mg L?1, respectively. Moreover, kinetic and thermodynamic analyses were used to study the reduction process, and possible mechanism of AR18 removal was discussed. The results show that the rGO/APT-nZVI composites can effectively degrade AR18 over a wide range of pH and keep degradation activity in a long storage. In addition, the superior behaviors for other organic dyes removal highlight the great potential as an efficient adsorbent for water pollution.  相似文献   

3.
茶皂素对潮土重金属污染的淋洗修复作用   总被引:15,自引:2,他引:13  
为了探讨茶皂素淋洗修复土壤重金属污染的可行性,该文采用振荡提取和土柱淋洗的方法,研究了茶皂素对污染土壤中重金属的去除作用。结果表明,茶皂素溶液的浓度和土壤的pH值对重金属去除率有明显影响。土柱淋洗试验中,采用质量分数7%茶皂素溶液作淋洗液,pH 5.0±0.1、土液质量体积比1:4为最佳淋洗修复条件,此时,Pb、Cd、Zn、Cu的去除率分别为6.74%、42.38%、13.07%、8.75%,去除率的大小顺序为Cd>Zn>Cu>Pb。茶皂素淋洗能有效去除酸溶态和可还原态的重金属,从而大大降低了重金属的环境风险,同时说明茶皂素用于土壤重金属污染淋洗修复有较大潜力。  相似文献   

4.
Agricultural solid wastes either in natural or in modified forms have been successfully used for decades as non-conventional cost-effective adsorbents for removing metal ions and dyes from their aqueous phase and have been recognized as a sustainable solution for wastewater treatment. Therefore, this review article provides extensive literature information about heavy metals and dyes, their classifications and toxicity, various treatment methods with emphasis on adsorption characteristics by numerous agricultural solid wastes, or agricultural solid waste-derived adsorbents under various physicochemical process conditions. This review article not only provided an up-to-date information on the application of sustainable low-cost alternative adsorbents such as agricultural solid wastes, agricultural by-products, and biomass-based cost-effective activated carbon and various other natural materials in the batch adsorptive removal of heavy metal and dye from aqueous phase but also presented a comprehensive compilation of adsorptive pollutant removal information based on various reported continuous column operation studies which is one of the new aspect to this review article. The effectiveness of various batch and column operational process parameters on mechanistic adsorptive removal of both heavy metals and dyes by various agricultural solid waste-based adsorbents has been critically discussed here. Batch and column adsorption mechanism, batch kinetics, column dynamic modeling, and adsorptive behavior of adsorbents under various process parameters have also been critically analyzed and compared. Finally, literature information on recovery and regeneration through desorption techniques and cost comparison of various agricultural solid waste adsorbents with commercial activated carbons have also been reported here. Conclusions have been drawn from the literature reviewed, and few suggestions for future research direction are proposed.  相似文献   

5.
通过增溶实验和土壤洗脱实验,研究了一种生物表面活性剂——皂角苷(saponin)对多环芳烃-重金属复合污染土壤的洗脱作用及机理。结果表明,皂角苷对菲、芘等多环芳烃有极强的增溶作用,当皂角苷浓度为0.04%时,菲、芘在液相中的表观溶解度分别增大了约22倍和128倍,因而皂角苷能显著增强多环芳烃污染土壤中菲、芘的洗脱,洗脱效率最大分别可达84.1%和81.4%,增大了约2倍和17倍。皂角苷可与重金属离子形成水溶性的络合物,从而增强洗脱重金属污染土壤中的Zn^2+和Cd^2+,在皂角苷浓度为0.4%时,Zn^2+、Cd^2+的洗脱效率分别可达93.0%和79.4%,增大了约75倍和8倍。皂角苷可同时洗脱多环芳烃-重金属复合污染土壤中的菲、芘和Zn^2+、Cd^2+,洗脱效率分别达87.6%、83.5%和92.3%、78.6%,重金属的存在略增大了皂角苷对菲、芘等多环芳烃的洗脱效率,但多环芳烃对Zn^2+、Cd^2+的洗脱效率没有明显影响。皂角苷可同时增强洗脱复合污染土壤中的多环芳烃和重金属,从而为多环芳烃-重金属复合污染土壤的修复奠定基础。  相似文献   

6.
周明珠  仓龙 《土壤》2022,54(4):653-666
基于过一硫酸盐(PMS)的高级氧化技术因反应快速高效、降解有机污染物效果优越,在环境修复领域拥有广阔的应用潜能。经过活化的PMS化学氧化技术在有机污染废水处理中被广泛应用,污染物的去除机制也在不断被发现并完善,其在有机污染土壤修复中也已得到应用。本文综述了PMS对有机污染物的化学氧化机制,分析了有机污染物降解的自由基和非自由基反应过程,探讨了不同活化方式(碱、过渡金属、碳基材料、辐射等)对PMS降解有机污染物的影响,阐述了PMS在有机污染土壤修复中的研究进展和存在问题,并进行了研究展望。  相似文献   

7.
Recently in Japan, like in other industrialized countries, treatment of contaminated soil or ground has become an important issue in redeveloping such areas as old factories, mining sites, and other polluted sites. In these cases, measures such as a construction of cut-off walls and disposal to controlled waste disposal sites have been so far taken. But, the treatment of contaminated soils has become more difficult nowadays. Therefore, remediation of contaminated soil by removal or extraction of contaminants is necessary and various methods have been developed and applied in many countries. Authors have tried to develop an electrokinetic remediation method for soil contaminated with heavy metals and some basic and pilot scale experiments have been carried out. In this paper, the results of a model experiment using an artificial soil contaminated with Cu or Ph or Cr are presented as follows. i) In the electrokinetic process, migration of water to the cathode by electroosmosis, migration of ions to the cathode or anode by electrophoresis and electrolysis of water occur spontaneously. ii) Upon DC loading, Cu and Pb migrate to the cathode and accumulate as oxides or hydroxides near the cathode but are not removed from contaminated soil. However, in the case of Cr contaminated soil, Cr in the form of Cr(VI) migrates to the anode and is removed from soil through the drainage water. iii) After DC loading for 2 weeks, the concentration of exchangeable cations and composition of soil changed drastically while the CEC and clay mineralogy did not change appreciably.  相似文献   

8.
Contact angles at the water–air interface have been measured for triturated preparations of clays and soils in order to assess changes in their hydrophobic properties under the effect of oil hydrocarbons. Tasks have been to determine the dynamics of contact angle under soil wetting conditions and to reveal the effect of chemical removal of organic matter from soils on the hydrophilicity of preparations. The potentialities of static and dynamic drop tests for assessing the hydrophilic–hydrophobic properties of soils have been estimated. Clays (kaolinite, gumbrine, and argillite) have been investigated, as well as plow horizons of soils from the Republic of Tatarstan: heavy loamy leached chernozem, medium loamy dark gray forest soil, and light loamy soddy-calcareous soil. The soils have been contaminated with raw oil and kerosene at rates of 0.1–3 wt %. In the uncontaminated and contaminated chernozem, capillary water capacity has been maintained for 250 days. The contact angles have been found to depend on the degree of dispersion of powdered preparation, the main type of clay minerals in the soil, the presence and amount of oxidation-resistant soil organic matter, and the soil–water contact time. Characteristic parameters of mathematical models for drop behavior on triturated preparations have been calculated. Contamination with hydrocarbons has resulted in a reliable increase in the contact angles of soil preparations. The hydrophobization of soil surface in chernozem is more active than in soils poorer in organic matter. The complete restoration of the hydrophilic properties of soils after hydrocarbon contamination is due to the oxidation of easily oxidizable organic matter at the low content of humus, or to wetting during several months in the absence of the mazut fraction.  相似文献   

9.
Development of treatment technologies to alleviate water pollution has been a challenging and demanding task for researchers. Furthermore, synthetic dyes fabricated of complex aromatic structures turned out to be a great hazard as they impart color to water reservoirs making them abhorrent for human use. Reactive dyes being water soluble prove difficult to be eliminated by conventional treatment technologies. In recent times, biosorption has gained prominence as a finishing technology to remove pollutants being cost-effective and environment friendly. This paper describes the hazards posed by dyeing effluents, exclusively reactive dyes, on the environment and use of various biosorbents to remove reactive dyes from aqueous solution under optimum physicochemical parameters. Enhancement of biosorption capacity by chemical treatment and immobilization; equilibrium, kinetic and thermodynamic modeling of biosorption process; characterization by FTIR and SEM and regeneration of biosorbents is also plainly and comprehensively discussed.  相似文献   

10.
Water pollution by P (phosphorous) is a serious water-related issue being faced by mankind during the past two decades. Several technologies already exist to remove P from contaminated water, but each has its own drawbacks. The present paper discusses a novel microwave-assisted synthesis of reduced iron oxide containing renewable-resource-based media for P removal from contaminated waters. It provides a fast, easy, and economical way to produce reduced iron oxide nanocomposites without requiring the need for hydrogen or inert gas during the transformation. A wide range of other metal/ carbon nanocomposites can also be synthesized using this technology and therefore holds tremendous economic promise. The prepared media were highly effective and efficient in removing P. A 100?% P removal efficiency was attained using a 1?mg/L standard P stock solution and a maximum capacity of 43.7?mg P/g of composite was achieved using 500?mg/L standard P stock solution. The present technology is highly economical as the carbon source employed was a renewable resource media with a high regeneration capacity. The present technology may also be used for arsenic removal from similarly contaminated water. The method of preparation of media, treatment methodology, and characterization methods are also discussed.  相似文献   

11.
重金属污染农田安全利用:进展与展望   总被引:3,自引:1,他引:2  
我国耕地土壤污染面积广,污染情况复杂,农产品重金属超标问题已经关系到国计民生。常用的物理化学修复方法成本高,不适用于大面积的中低污染农田。植物提取修复方法成本低,环境友好,但修复时间长,推广困难。总的来讲,基于重金属移除的诸技术在解决农田重金属污染方面还没有太大优势。相较而言,农田安全利用在不移除或缓慢移除土壤重金属的条件下,以生产安全农产品为目标,具有更加坚实的现实意义和推广价值。种植低吸收农作物是安全利用的重要措施,基因工程手段在低吸收农作物品种筛选中具有巨大的潜力,但其可能带来的生态环境风险使得这些通过基因工程得到的低吸收作物的田间种植面临着巨大挑战。土壤添加剂可以改变土壤重金属形态,降低重金属的生物有效性,但会对土壤质量产生影响。微生物尤其是土著微生物的利用越发受到关注,改变微生物的生存环境与基因工程手段能够强化微生物的钝化效果。施肥、水分管理、间作等农艺措施也能改变土壤重金属的形态,抑制作物对重金属的吸收。未来以加强推广为目的,多种技术手段的联合应用是重金属污染农田安全利用的重要发展方向,其中以生物技术为核心的利用模式具有十分重要的意义。  相似文献   

12.
Mesoporous silica with wormhole framework structure (HMS-OH) and its amine-functionalized material (HMS-NH2) were prepared through an electrically neutral assembly pathways, post-grafting process of 3-aminopropyltriethoxysilane (APTES), respectively. Their adsorption behaviors toward cationic dyes as well as heavy metal ions in aqueous system and the capture capacities for CO2 molecules all have been investigated. As-synthesized HMS-OH showed a high removal efficiency and rapid sorption rate to cationic dyes because of large surface area and versatile pore structure. HMS-NH2 exhibited better heavy metal ions and more CO2 gas sorption capacities due to the intrinsic property of amine groups grafted on the surface. The adsorption isotherms of methylene blue (MB) onto HMS-OH, Cu(II) onto HMS-NH2 were fitted with Langmuir model and kinetic processes followed well the pseudo-second order pattern. There results revealed that both HMS-OH and HMS-NH2 had a potential application in the treatment of cationic dyes, heavy metal ions, and greenhouse gas CO2.  相似文献   

13.
[目的]评价α-淀粉酶与茶皂素对污染土壤中的Cd,Pb洗脱效果,为重金属污染土壤的修复提供更准确的科学依据。[方法]以重金属Cd,Pb污染的耕作层土壤为研究对象,利用α-淀粉酶和茶皂素复合淋洗对Cd,Pb污染土壤进行生态修复,并测定土壤淋洗前后Cd,Pb形态的变化。[结果]在反应时间12h,pH 4.0,反应温度30℃,茶皂素溶液和酶溶液配比4∶1条件下,Cd,Pb去除率分别为88.87%,43.97%。通过对修复前后重金属的形态分析,发现酸提取态、可还原物态的重金属较容易去除,淋洗后土壤中Cd和Pb均达到土壤环境质量Ⅱ级标准。[结论]α-淀粉酶和茶皂素组合对土壤中Cd,Pb有明显的去除效果,起到协同、增强作用。表明α-淀粉酶和茶皂素组合在生态修复重金属污染的土壤方面具有一定的应用前景。  相似文献   

14.
Remediation of ecosystems that have been exposed to radionuclides is of great importance for many countries. At present the remediation efforts using existing technologies are rather expensive. Phytoremediation can serve as a perspective method for rehabilitation of the radioactive contaminated soils and wastes. Among other radio-nuclides, limited information is available on screening and selection of plants for thorium uptake. In our work short-term pot experiments in a greenhouse have been performed to study the phytoextraction of thorium by wheat seedlings grown in soil and different water media artificially contaminated with thorium. Addition of a small amount of thorium to the media resulted in a significant increase of thorium concentration both in roots and leaves of the wheat seedlings. The uptake of Th by roots depended of the media where the plants grew: it was more significant in water-grown plants. The rate of Th translocation from roots to leaves was approximately the same regardless of the growth medium. The bioaccumulation of Th in the wheat resulted inthe removal of Th from the soil and water. During the short-term vegetation test concentration of Th in all the media decreased: in water — 2—5 times, in soil — 1.7 times. Th accumulation in the wheat seedlings affected concentrations and relationships between other elements in the plants. More significant changes were found in the wheat grown in doubly distilled water and in nutrient solution.The most affected part of the plants was the root system.  相似文献   

15.
印度芥菜(Brassica juncea L.)重金属耐性机理研究进展   总被引:4,自引:0,他引:4  
印度芥菜可富集/忍耐Cd、Zn 等多种重金属, 是研究植物修复技术的一种模式植物。高浓度的重金属离子会改变植物的基因表达、细胞形态、细胞结构, 最终使植物生长受抑, 甚至死亡。印度芥菜高效的抗氧化系统、损伤修复系统以及对重金属的螯合、区域化可部分解除重金属的毒性, 缓解重金属离子的毒害作用。利用基因工程技术在印度芥菜中导入重金属耐性及运输相关基因可大幅度提高其重金属富集能力, 在重金属污染修复方面具有广阔的应用前景。  相似文献   

16.

Purpose  

Prometryne with moderate to low mobility in soil is a ubiquitous environmental pollutant in water and soil. Bioremediation is widely used to remove pollutants from contaminated soil. Bacterial-feeding nematodes have been tested on the decomposition of soil organic matter and the release of nutrients through their interaction with soil microorganisms, but little attention has been paid to their effects on the removal of herbicides in soil. In this study, we investigated the effects of bacterial-feeding nematodes (Cephalobus Bastian) on the dissipation of prometryne and microbial activity in prometryne contaminated soil.  相似文献   

17.
The textile industry is known to generate large quantities of effluents contaminated with dyes that are not fixed to the fibers during the dyeing process. The available technologies to remove these dyes from the wastewater are expensive and ineffective. Within this context, low-cost, easy-maintenance technologies for the removal of dyes have been studied, such as adsorption on aquatic macrophytes. Thus, the macrophyte Salvinia sp., raw or pretreated with NaOH or H3PO4, was used as biosorbent of Blue 5G reactive dye. The study showed that pH and temperature affect the dye removal capacity. The analysis of the infrared spectrum (FTIR) showed that chemical treatment of the Salvinia sp. modified the biomass surface and affected dye adsorption capacity. The pseudo-second-order kinetic model satisfactorily described the experimental data for raw and NaOH-pretreated biomass, and the pseudo-first-order model was more appropriate to describe the experimental data obtained with H3PO4-pretreated biomass. The highest capacity of Blue 5G dye removal was obtained with raw biomass, at 333?K and pH?1.0, with 98.35?% adsorption.  相似文献   

18.
The interaction between fluvially transported, metal contaminated peat particulates and acidic waters draining peatland catchments has received limited attention. Potential in-stream processing of sediment-associated metals in acidic stream water was investigated in laboratory based mixing experiments, designed to represent conditions of fluvial sediment transport in a highly contaminated and severely eroding peatland catchment in the Peak District (UK). Over the initial 20 min of the first experiment, stream water Cr and Zn concentrations increased by at least an order-of-magnitude and remained elevated for the full duration (24 h) of the experiment. Stream water As, Mo, Pb, Ti and V concentrations increased between 43% (As) and 440% (V) over the first hour of the experiment. After 24 h most of the metals appeared to have reached equilibrium in the water column. Results of the second experiment revealed that when the concentration of metal contaminated peat particulates is increased, there is an associated increase in the stream water As, Cr, Mo, Pb, Ti, V and Zn concentrations. The experimental data suggest that As, Cr, Mo, Pb, Ti, V and Zn are liable to desorption from metal contaminated peat into acidic stream water. The solubilisation of contaminated peat particulates may also contribute to elevated stream water metal concentrations. The laboratory based approach used in this study may indicate that when there is erosion of metal contaminated peat into acidic fluvial systems there is a concomitant increase in dissolved metal levels, especially when suspended sediment concentrations are high. Further laboratory and field based experiments are required to evaluate the relative importance of physical and chemical processes in the interaction between contaminated peat particulates and stream water in peatland fluvial systems.  相似文献   

19.
重金属污染土壤的螯合剂诱导植物修复研究进展   总被引:4,自引:0,他引:4  
植物修复作为一种生态友好型原位绿色修复技术成为重金属污染土壤修复研究的热点。然而,目前最具有推广价值的超积累植物因生物量低、生长缓慢、对重金属的积累具有专一性等缺点,大大限制了植物修复技术在重金属污染尤其是复合重金属污染土壤治理方面的推广应用。利用生长速度快、生物量大的普通植物借助其它技术辅助的联合植物修复便成了有效可行的替代途径和研究焦点。近年来,金属螯合剂诱导的化学-植物联合修复技术备受关注。本文综述了螯合剂诱导植物修复技术的研究进展、修复机理和目前存在的问题,并对该项技术的未来研究方向给予了展望。  相似文献   

20.
在室内模拟实验条件下,重点研究了一步和二步生物淋滤过程中黑曲霉利用各种廉价碳源替代蔗糖产酸修复重金属污染土壤的效果。结果发现,杨树叶、桃树叶、土豆皮去除重金属效果较好。其中杨树叶对冶炼厂土壤中重金属去除率分别为Cu63.5%、Cd100%、Pb16.8%和Zn27%;桃树叶去除效果分别为Cu61.8%、Cd100%、Pb14.6%和Zn28.5%;土豆皮去除效果分别为Cu61%、Cd100%、Pb10.6%和Zn34%。廉价碳源的使用可降低污染土壤生物淋滤修复成本。  相似文献   

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