Study on Obstacles to Continuous Cropping of Vegetables and Soil Remediation Technology

Firstly,this paper analyzes the cause of obstacles to continuous cropping of vegetables,and then introduces the soil ecological remediation technology used for overcoming obstacles to continuous cropping of vegetables. Finally,this paper analyzes the effect of applying soil ecological remediation technology in overcoming obstacles to continuous cropping of vegetables.

Analysis of Soil Remediation Technology for Heavy Metalcontaminated Sites in Electroplating Enterprises

The advantages and disadvantages of chemical leaching,phytoremediation,in-situ/ex-situ solidification and stabilization,cement kiln co-disposal and safe landfill remediation are analyzed.In addition,the application of chemical leaching and in-situ/ex-situ solidification and stabilization technology in the treatment of heavy metal-contaminated soil in electroplating enterprises in China is introduced in detail to provide reference for the remediation of heavy metal-contaminated soil around electroplating enterprises in China.

Overview of Patented Technologies for Remediation of Soil Pollution

Soil, an important material basis for human activities, is an indispensable natural rasource that is difficult to regenerate. It is also an important part of human ecological environment. Currently, soil pollution has affected China＇s agricultural production and threatened human health and ecological safety, so it has been paid more attention to by the people and has become a hot spot in environmental field. Through continuous research, a variety of soil remediation patents and technologies also emerge. Here, by retrieving the main words through the website （www. soopat. corn） and Chinese patent net, types of soil pollution and remediation technologies under the authorization status of the patents were analyzed, and the major species of soil pollutants and soil remediation technologies were reviewed.

Site Pollution Remediation and Its Technology

This paper summarized the connotation of contaminated site remediation,the differences between contaminated site and brownfield,the differences between contaminated site and soil pollution and land pollution,clarified the relationship between the concepts,and introduced the remediation technology of contaminated site.

Study of polluted soil remediation based on freezing and thawing cycles

It is generally known that soil pollution poses a terrible hazard to the environment, but the present techniques of contaminated soil remediation cannot control this growing threat. This paper compares the pollutant extraction efficiency of traditional pumping and treating, which is a typical washing technology for the remediation of contaminated soils, with methods that utilize freeze-thaw cycles. In the soil freezing process, water shifts from unfrozen soils to the freezing front, and the permeability of soil will be enhanced under certain temperature gradients and water conditions. Therefore, this paper discusses the purification of contaminated soil through freeze-thaw action. We conducted a cleansing experiment on clay and silica sand infused with NaCl（simulation of heavy metals） and found that the efficiency of purification was enhanced remarkably in the latter by the freeze-thaw action. To assess the effective extraction of DNAPLs in soil, we conducted an experiment on suction by freezing, predicated on the different freezing points of moisture and pollutants. We found that the permeability coefficient was significantly increased by the freezing-thawing action, enabling the DNAPL contaminants to be extracted selectively and effectively.

In-situ remediation of deep petroleum-contaminated soil injection

A computational fluid dynamics(CFD)numerical simulation and field experiment were used to investigate optimal operating parameters of high-pressure jet grouting equipment and clarify the boundary law of the injection area in the remediation process.The response surface optimization design results show that the optimal injection pressure is 30 MPa,rotation speed is 23 r/min,commission speed is 30 cm/min,and the optimal injection diameter is 147.3 cm.Based on the CFD numerical simulation,the ratio of the injection core,turbulent zone,and seepage zone is approximately 1∶4∶2.The distribution law of jet core,turbulence zone and seepage zone at different cross-sections under 30 MPa operating conditions is as follows:The jet core radius is approximately 100 mm,the turbulence zone is mainly distributed at 100 to 500 mm,the seepage zone is mainly distributed at 500 to 700 mm,the seepage zone could be completed within 2 h,and the proportion of the three boundary zones in the injection zone is similar to that of the numerical simulation.This study provides theoretical parameters and practical reference for the remediation of deep pollution via in-situ chemical oxidation in the Loess Plateau soil environment.

A comparative study of methods for remediation of diesel-contaminated soil

Soil pollution by diesel fuels is a worldwide environmental problem,but little research has been carried out into on-site techniques for remediation of soil polluted by waste solvents.This study compared chemical oxidation and soil washing methods for their efficiency and environmental and economic impacts.Soil was spiked with 0#diesel to simulate an actual pollution level of about 1260 mg/kg total petroleum hydrocarbon(TPH).Fenton-like oxidation eliminated 90.4%of the TPH with a Fe2+׃H2O2 ratio of 1:10 in 5 d compared with 25.8%removal by the activated persulfate method under the same conditions.In washing tests,sodium dodecylbenzenesulfonate and Tween 80 were both unsuitable for TPH washing,while ultrapure water removed 36.1%of TPH in 75 min.Only the Fenton-like oxidation technique met remediation goals based on the screening values of the Guideline for Risk Assessment of Contaminated Sites.The environmental impact and economic assessment of techniques demonstrated the superiority of water washing for dealing with low-degree TPH contamination.

重金属污染土壤修复技术的可行性研究与实践

重金属污染土壤已成为全球性环境问题,严重威胁人类健康和生态安全。本文综述了物理修复、化学修复和生物修复等主要修复技术的原理、方法和适用条件,重点探讨了它们的优缺点和实际应用效果。通过对不同技术的可行性分析和对比,综合考虑成本、效率、环境影响等因素,提出了因地制宜、多技术联合修复的策略建议。本研究对指导重金属污染土壤治理实践、开发优化新型修复技术具有重要意义,可为区域环境管理决策提供科学依据。

Removal of Heavy Metal from Contaminated Soil with Chelating Agents

Removal of copper and nickel by the addition of the biodegradable chelating agent, chitosan and ethylenediamine tetraacetic acid (EDTA), was investigated, alongside the reaction of a reference compound sodium citrate for comparison. The artificial-contaminated soils were used in this study. The experiments showed that the extraction ability for copper and nickel from the contaminated soil decreased as follows: chitosan > EDTA > sodium citrate. The pH value of the eluents is the key to control the extraction, especially to chitosan solution. It was evident that the chitosan solution was the most efficient when the pH value was 3 - 3.5, the rate of extraction of copper being 43.36% and of nickel being 37.07%. And the best match of concentration and liquid/solid was 0.3 g/L and 10 mL/g.

Managing international collaboration for the development and application of environmental technologies: opportunities for China & other Asia Pacific countries

Increased international cooperation in the field of contaminated site management has resulted in the formation of numerous networks and fora. The key benefits of increased co\|operation are perceived to be in the reduction of duplication in efforts, particularly related to industry, in the co\|ordination of contaminated site research, policy development and information dissemination. The paper introduces and briefly discusses key networks and collaborative projects currently in operation throughout the world relating to contaminated site management. The experience shared within these groups should prove useful to the application of such environmental problems in China and the Asia\|Pacific region.

重金属环境污染修复技术研究和应用进展

随着人类社会的高度发展,重金属污染问题越来越严重,已经成为全球性重大环境问题。而由于重金属具有不可降解性、隐蔽性和积累性,其治理起来存在很大难度,目前还没有普遍适用的治理方法。本文对重金属环境污染的物理、化学和生物修复方法的研究与应用进展进行了介绍,分析了各种方法的优缺点,并对重金属环境污染修复技术的未来发展方向进行了展望。

基于应对土壤污染的优化淋洗技术研究

随着土壤污染问题的愈发严峻,土壤淋洗技术作为应用最为广泛的土壤修复技术之一,正受到广泛聚焦。本文通过对ALLU斗与异位土壤淋洗技术结合处理污染土的研究,从技术路线、修复车间剖面布置、平面布置3个维度进行设计,以某氰化物污染地为实验对象进行两次现场试验。实验结果表明了研究提出的ALLU斗与异位土壤淋洗技术结合处理污染土可行。

长江经济带工业区污染场地特征及修复技术选择分析

掌握工业场地污染特征及修复技术选择信息,明确场地污染防治需求,对长江经济带工业区污染场地土壤污染防治及再开发安全利用具有重要意义.本文对长江经济带工业区621个污染场地修复治理的案例数据进行调研,采用相关性分析等方法,对工业场地的污染特征及修复技术的优先选择进行了综合解析.结果表明:砷、镍、汞、铅、铬、锌、镉、苯、1,2-二氯乙烷、氯仿、苯并[a]芘和石油烃是长江经济带工业区的主要目标污染物,也是引起下游地区以复合型污染为主(48%)的主要因子,而砷、铅、镉、铬等的普遍存在是造成中上游地区以无机型污染为主(上游无机型污染占48%,中游占67%)的主要原因;化学原料和化学制品制造业污染场地中涉及污染物种类(116种)最多,占据长江经济带工业区污染场地中发现污染物种类的85%;调研的案例中污染深度较大的场地(污染深度>10 m)多集中于下游地区,可能受场地土层结构、污染物本身性质以及企业的生产年限等因素影响;目前长江经济带工业区污染场地修复技术多选择异位修复,主导因素为场地污染类型、用地规划以及修复效果和工期.研究显示,长江经济带工业区场地污染特征具有区域性,以异位固化/稳定化、水泥窑协同处置和异位化学氧化为主的异位修复技术应用广泛,未来需要进一步加强引导土壤污染防治向绿色低碳发展.

高温活化磷尾矿钝化矿区污染土壤中阳离子态重金属研究

矿冶场地土壤重金属污染是重要的环境问题,亟需研发低成本的高效修复技术。化学钝化是常用修复技术,但现有钝化材料仍存在效率较低、成本较高等问题。本研究采用900℃高温处理制备活化磷尾矿材料,研究不同处理下材料对土壤重金属的钝化效果。结果表明:高温处理将磷尾矿中的白云石分解为方解石、MgO和CaO,活化材料可显著提升土壤pH,降低土壤可交换态重金属含量;添加0.8%的高温活化磷尾矿钝化30天后,土壤可交换态Zn、Cd和Pb含量分别降低97%、46%和95%。重金属由可交换态向碳酸盐结合态转化,部分Cd转化为铁锰氧化物结合态。主要钝化机理为MgO与水反应生成氢氧化物提升土壤pH,促使重金属形成氧化物、氢氧化物沉淀,同时增加铁锰氧化物对Cd的吸附固定。研究结果可为矿区土壤原位钝化和磷尾矿资源化利用提供参考。

铁尾砂资源化利用及铁矿区土壤修复技术研究进展

随着铁矿资源的持续大规模开采,铁尾砂量逐年增加,因其综合利用率低,不仅占用了大量土地资源,还引发了土壤重金属污染等环境问题。本文综述了我国铁尾砂在工业和农业领域的资源化利用现状,指出了铁尾砂资源化利用存在的问题;总结了铁矿区土壤污染修复技术如物理修复、化学修复、生物修复以及联合修复技术的优缺点,提出了铁矿区土壤污染修复发展对策,以期为我国铁矿产业高质量发展提供参考。

水肥一体化技术对蔬菜影响的研究进展

水肥一体化技术作为一种现代化的农业生产管理技术,旨在实现水资源与肥料的高效利用,提高蔬菜产量和品质,改善土壤理化性质等。近年来,随着农业科技的发展,蔬菜水肥一体化技术在国内外得到广泛的研究与应用。该文主要概述蔬菜水肥一体化技术的研究进展,通过实时监测土壤水分和养分含量,精确调控灌溉和施肥量,提高产量和品质的同时又促进水肥的高效利用,根据作物生长需求,合理配置水资源和肥料资源。尽管蔬菜水肥一体化技术取得显著成果,但仍面临一些关键的技术性问题。该文在分析总结的基础上,提出对水肥一体化技术的建议与展望,旨在为相关领域的研究和应用提供参考,助力我国农业现代化发展。

酸性土壤中重金属钝化技术研究进展

阐述了土壤中重金属的赋存形态以及土壤pH对重金属赋存形态的影响,综述了无机钝化剂、有机钝化剂、无机-有机复合钝化剂、新型钝化剂以及钝化剂-微生物联合修复酸性土壤中重金属污染的研究进展,指出钝化修复技术面临的问题和挑战,提出酸性土壤中重金属钝化的优化方案:利用各类型钝化剂的优点进行复配或改性、优化制备过程、研究新型钝化剂在长期田间环境下的稳定性、监测材料对环境及生物的影响;根据不同污染类型、污染程度选择合适的治理方案;建立更完善的土壤污染防治体系,加强土壤污染监测和评价;优化耕地的水管理、施肥管理和轮作管理。

电动-化学淋溶联合修复铀污染土壤

矿山周围土壤放射性污染问题对生态环境及人体健康构成威胁,亟需对铀污染土壤展开高效修复技术研究。以某铀矿区的放射性污染土壤为研究对象,探究不同淋溶剂类型、淋溶剂浓度、液固比及复合淋溶剂配比去除铀的最佳工艺参数。结果表明:化学淋溶剂对铀污染土壤中铀的去除性能存在明显的差异,表现为无机酸(48.70%)>有机酸(31.91%)>螯合剂(23.31%)>无机盐(17.26%)。复合淋溶剂及电动化学淋溶法的联合使用可有效提高污染土壤中铀的去除率,其中,在电压30 V、柠檬酸+氯化铁复合浓度0.1 mol/L+7.5 g/L、液固比5 mL/g、温度25℃的最佳条件下,污染土壤中铀的平均去除率达59.75%,较单一化学淋溶提高了13.37个百分点。

过碳酸钠-过硫酸钠双氧化体系降解地下水中三氯乙烯

为了解决单一氧化体系降解地下水中三氯乙烯的效率不高的问题,采用柠檬酸螯合Fe^(2+)催化过碳酸钠与过硫酸钠协同降解地下水中的三氯乙烯,考察过碳酸钠和过硫酸钠的配比、水质条件(pH、典型阴离子)以及三氯乙烯的初始浓度对三氯乙烯降解效率的影响。结果表明,当三氯乙烯的初始浓度为0.16 mmol/L时,在中性条件下,柠檬酸螯合Fe^(2+)催化过碳酸钠-过硫酸钠双氧化体系可以显著提高地下水中三氯乙烯的降解速率;三氯乙烯的降解受过碳酸钠与过硫酸钠的配比的影响,过碳酸钠、过硫酸钠、柠檬酸、 Fe^(2+)、三氯乙烯的物质的量比为10∶8∶5∶10∶1时,反应180 min后三氯乙烯的降解率为98.5%;随着反应体系pH增大,三氯乙烯的降解率逐渐降低;地下水中常见的阴离子SO_(4)^(2-)、 NO_(3)^(-)对该双氧化体系去除地下水中三氯乙烯的影响较小,但较高浓度的HCO_(3)^(-)、 Cl^(-)显著抑制三氯乙烯的降解;自由基清扫实验确定双氧化体系中存在氢氧自由基HO·、硫酸根自由基SO_(4)^(-)·、超氧自由基O_(2)^(-)·等自由基,且HO·对三氯乙烯的降解起主导作用。

课程思政背景下土壤污染修复技术课程教学改革探索

土壤污染修复技术是一门涵盖土壤物质组成、理化性质、污染控制与修复“全过程”的专业课程,如何在课程讲解过程中培养学生的职业认同感及使命感,是实现课程思政教育的重点。该课程以培养学生解决实际土壤污染问题为导向,针对国家目前对土壤污染修复领域的科学技术和人才需求,将专业课程与思政教育有机结合,以理论教学为基础,设计实践为重点,创新教学方法,突出以学生为中心的教学原则,结合“成果导向”(OBE)的教育理念,开展以学生为中心的多种教学形式,引导学生积极参与,培养学生学以致用的家国情怀和使命担当意识。