Remediation

补救
  • 文章类型: Journal Article
    Green liquor dregs (GLD) is an alkaline by-product from the pulp and paper industry with a pH between 10 and 14. Today most of the produced GLD in Sweden is landfilled. As a fine-grained alkaline material, it might be possible to use it for acid-generating mining waste remediation. To increase the utilization, quality characteristics and environmental performance need to be determined. In this study samples were collected 5 times from 16 mills during a period of 2.5 years, and were characterized by analyzing dry matter content, loss on ignition (LOI) 550 °C and LOI 950 °C, elemental analysis, pH, electrical conductivity, and calorific value. The results were then evaluated using multivariate statistics (PCA) as well as being compared to other studies and Swedish till. The results show that even if GLD is heterogenous (both within a mill and between different mills) trends can be seen for samples from most mills. When samples do stand out, it is predominately related to the same four mills. Most of the studied parameters showed characteristics favorable for use as a remediant; however, TOC, sulfur, and some of the elements require further study. In general, this study concludes that GLD can be a viable option for the remediation of small orphaned sulfidic mining sites and thus worthy of further studies on the interaction between GLD and acidic mining waste.Overall, GLD can be a good alternative for cost-effective remediation of smaller orphaned mining sites. It is readily available in large quantities, has the qualities needed for remediation of many orphaned acidic mining sites, and can often be locally sourced near the mining site. The use of GLD for mining site remediation is likely also a more sustainable method compared to traditional remediation methods.
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  • 文章类型: Journal Article
    现象:随着本科医学教育前阶段通过/失败分级做法的激增,出现关于评分和等级报告实践的透明度和可变性的问题,在评估中提出公平问题,特别是关于居住匹配。这项调查的目的是确定美国(U.S.)同种疗法医学院在其课程的实习前阶段的补救和学业成绩报告做法。方法:经过广泛的文献检索和课程院长和学习专家的反馈,我们制定了一项调查,该调查于2022年春季发送给美国所有154所认可的对抗疗法医学院的教前课程官员.它涉及课程内容和结构;文员前补救(例如,课程重考)和报告(例如,成绩单表示法的持久性)实践;非学术能力的文档和报告;以及参与者关于报告的意见和建议,透明度,和公平。我们生成了描述性统计数据,并显示了开放式响应的编码。研究结果:我们的应答率为40%(62/155),超过71%的人表示主要是基于器官系统的课程。视情况而定,对于单道和多道失败有广泛的补救方法,包括辅导或学习支持,重新考试,并转介给晋升委员会。专业关注是向居民总监报告的首要任务,在报告补救活动时,受访者的意见和做法存在显著差异。受访者担心公平,在灵活的评级做法和报告做法的透明度方面。见解:学校报告实践的可变性,在允许整体和个性化的学术支持方法的同时,也会造成潜在的不平等。需要做更多的工作来了解不同机构的不同报告做法如何在准备工作的不同阶段使边缘化和少数族裔学生群体处于不利地位。
    Phenomenon: With the proliferation of pass/fail grading practices in the pre-clerkship phase of undergraduate medical education, questions arise about the transparency and variability of grading and grade reporting practices, raising issues of equity in assessment, particularly regarding residency matching. The purpose of this survey was to determine the remediation and academic performance reporting practices of United States (U.S.) allopathic medical schools in the pre-clerkship phase of their curricula. Approach: After an extensive literature search and feedback from curriculum deans and learning experts, we developed a survey that we sent in the Spring of 2022 to pre-clerkship curriculum officials at all 154 accredited U.S. allopathic medical schools. It addressed curriculum content and structure; pre-clerkship remediation (e.g., course retakes) and reporting (e.g., permanency of transcript notation) practices; documentation and reporting of nonacademic competencies; and participant opinions and recommendations regarding reporting, transparency, and equity. We generated descriptive statistics and did manifest coding of open-ended responses. Findings: We had a response rate of 40% (62/155), with over 71% indicating mainly organ systems-based curricula. Depending on the situation, there were a wide range of remediation approaches for single- and multiple-course failures, including tutoring or learning support, re-exams, and referrals to a promotion board. Professionalism concerns were a top priority to report to residency directors, with significant variability in respondent opinions and practices in reporting remedial activities. Respondents were concerned about equity, both in terms of flexible grading practices and transparency of reporting practices. Insights: The variability in reporting practices across schools, while allowing holistic and individualized approaches to academic support, also creates potential inequities. More work is needed to understand how different reporting practices across institutions may disadvantage marginalized and minoritized student groups at different points in their preparation.
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  • 文章类型: Journal Article
    原位固定是一种潜在的方法,可用于修复受污染土壤中低至中等水平的重金属。对土壤特性的改变如何影响土壤中铅的释放还知之甚少。四个不同的修正案,三重过磷酸钙和凹凸棒石在Ad-1中结合;沸石和三重过磷酸钙在Ad-2中;羟基磷灰石和腐殖质在Ad-3中;和纳米碳。这些改良剂主要由页硅酸盐矿物制成,腐殖质,基础矿物,和纳米碳,分别。结果表明,试验修正值的最大铅吸附容量在7.47至17.67mgg-1之间。发现表面沉淀和离子交换是Ad-1和Ad-2吸附Pb的主要机制,而Ad-3和Ad-4在所有这些机制中都很有希望。根据对Pb加载前后改性的分析。当pH值下降(7-1)或离子强度上升(0-0.2M)时,修订后的铅解吸百分比有明显上升。确定Ad-3和Ad-4在污染土壤中的原位固定铅更有效,因为它们具有高吸附能力(12.82和17.67mgg-1)和低解吸百分比(4.46-6.23%)离子强度为0.01-0.1molL-1,pH水平为5至7。
    这项研究开创了对新型土壤改良剂功效的全面探索,Ad-3和Ad-4由页硅酸盐矿物制成,腐殖质,基础矿物,和纳米碳,展示了他们在减轻铅污染方面前所未有的潜力。通过深入研究处理土壤中铅吸附和解吸的复杂机制,这项研究填补了一个关键的空白,在理解如何改变土壤的特性可以影响二次释放的铅,从而为在铅濒危环境中保护植物和人类健康的量身定制的原位修复策略提供必要的见解。
    In situ immobilization is a potential approach that can be used to remediate low-to-medium levels of heavy-metal in contaminated-soil. There is little known about how modifications to soil characteristics may affect Pb\'s release from soil. The four different amendments, triple-superphosphate and attapulgite were combined in Ad-1; zeolite and triple-superphosphate were in Ad-2; hydroxyapatite and humus were in Ad-3; and nano-carbon. These amendments are mostly made of phyllosilicate minerals, humus, base minerals, and nano-carbon, respectively. Results revealed that the test amendments\' maximal Pb-adsorption capacity varied from 7.47 to 17.67 mg g-1. Surface precipitation and ion-exchange were found to be the main mechanisms for Pb-adsorption by Ad-1 and Ad-2, while Ad-3 and Ad-4 were promising among the all, according to analysis of the modifications both before and after Pb loading. When the pH dropped (7-1) or the ion-strength rose (0-0.2 M), there was a discernible rise in the Pb-desorption percentages from the amendments. It was determined that Ad-3 and Ad-4 were more effective in situ immobilizing lead in contaminated-soils because of their high adsorption capacities (12.82 and 17.67 mg g-1) and low-desorption percentages (4.46-6.23%) at ion-strengths of 0.01-0.1 mol L-1 and pH levels ranging from 5 to 7.
    This study pioneers a comprehensive exploration into the efficacy of novel soil amendments, Ad-3 and Ad-4 crafted from phyllosilicate minerals, humus, base minerals, and nano-carbon, showcasing their unprecedented potential in mitigating lead pollution. By delving into the intricate mechanisms of lead adsorption and desorption within treated soils, this research fills a critical gap in understanding how modifications to soil characteristics can influence the secondary release of lead, thus providing essential insights for tailored in situ remediation strategies to safeguard both plant and human health in lead-endangered environments.
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  • 文章类型: Journal Article
    加沙当前人道主义灾难的一个未得到充分认可的方面是战争对环境的影响以及对人类健康的相关风险。本评论将这些影响置于与对加沙普通民众使用武力有关的压倒性暴力所造成的人类苦难的背景下。呼吁立即停止暴力,作者提请注意重建医疗保健系统和恢复物质和人类基础设施的迫切需要,这些基础设施使宜居环境成为可能,促进人类健康和福祉,特别是对于人口中最脆弱的人。因此,环境补救应成为协助重建的国际努力的最重要部分之一,我们希望巴勒斯坦人和以色列人将通过它实现持久和平,健康,和可持续发展,所有这些都是公认的国际人权义务的一部分。
    An under-recognised aspect of the current humanitarian catastrophe in Gaza is the impact of the war on the environment and the associated risks for human health. This commentary contextualises these impacts against the background of human suffering produced by the overwhelming violence associated with the use of military force against the general population of Gaza. In calling for an immediate cessation to the violence, the authors draw attention to the urgent need to rebuild the health care system and restore the physical and human infrastructure that makes a liveable environment possible and promotes human health and well-being, especially for the most vulnerable in the population. Environmental remediation should therefore form one of the most important parts of international efforts to assist reconstruction, through which we hope Palestinians and Israelis will achieve lasting peace, health, and sustainable development, all as part of accepted international human rights obligations.
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  • 文章类型: Journal Article
    一种新型吸附剂,海藻酸钙改性HAP(羟基磷灰石)-木耳蘑菇棒生物炭(CA-HAPMB),合成了Cd和Pb在土壤中的固定化。超过150天,在湖南省郴州市(CZ)和辽宁省沈阳市(SY)的污染土壤中以0%-3%的浓度施用CA-HAPMB,导致Cd和Pb的有效浓度降低。具体来说,在CZ土壤中,Cd和Pb分别下降30.9%-69.3%和31.9%-78.6%,分别,在SY土壤中,分别下跌27.5%-53.7%和26.4%-62.3%,分别。表征结果,从土壤中分离CA-HAPMB后获得,表明络合,共沉淀,离子交换在CA-HAPMB高效固定Cd和Pb中起着至关重要的作用。此外,调节添加的CA-HAPMB的量可以调节土壤pH值,导致土壤有机质和养分含量增加。用CA-HAPMB处理固定Cd和Pb后,土壤细菌的丰度和多样性增加,进一步促进重金属固定化。
    A novel adsorbent, calcium alginate-modified HAP (Hydroxyapatite)-wood ear mushroom sticks biochar (CA-HAPMB), was synthesized to enhance the immobilization of Cd and Pb in soil. Over 150 days, applying CA-HAPMB at concentrations of 0%-3% in contaminated soils from Chenzhou City in Hunan Province (CZ) and Shenyang City in Liaoning Province (SY) resulted in decreased effective concentrations of Cd and Pb. Specifically, in CZ soil, Cd and Pb decreased by 30.9%-69.3% and 31.9%-78.6%, respectively, while in SY soil, they decreased by 27.5%-53.7% and 26.4%-62.3%, respectively. Characterization results, obtained after separating CA-HAPMB from the soil, indicate that complexation, co-precipitation, and ion exchange play crucial roles in the efficient immobilization of Cd and Pb by CA-HAPMB. Additionally, adjusting the amount of CA-HAPMB added allows modulation of soil pH, leading to increased soil organic matter and nutrient content. Following treatment with CA-HAPMB for immobilizing Cd and Pb, soil bacteria abundance and diversity increased, further promoting heavy-metal immobilization.
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  • 文章类型: Journal Article
    由于过量使用,兽用抗生素已成为水和废水来源中的新兴污染物,对传统水和废水处理的毒性和抗性。本研究探索了使用Ti-RuO2/IrO2阳极的电化学氧化(EO)降解模型抗生素-氟苯尼考(FF)。使用SEM-EDS研究对阳极材料进行了表征,该研究表明了相邻金属氧化物之间的稳定结构和最佳相互作用。EDS结果显示Ru的存在,Ir,Ti,O和C元素占6.44%,2.57%,9.61%,52.74%和28.64%的原子重量百分比,分别。优化研究表明,pH5,30mAcm-2电流密度和0.05MNa2SO4对于5mgL-1FF在360分钟的处理时间内达到了90%的TOC去除率。降解遵循伪一级动力学。LC-Q-TOF-MS研究揭示了六种主要的副产物,说明了羟基化,放气,脱氯是FF电化学氧化过程中的主要降解机理。离子色谱研究显示Cl-的增加,F-和NO3-离子随着治疗时间的推移,在治疗的初始阶段后,Cl-减少。使用斑马鱼(Daniorerio)幼虫进行的毒性研究表明,处理过的样品具有毒性,可诱发发育障碍,例如心包水肿,卵黄囊水肿,受精后96小时(hpf)的脊柱弯曲和尾巴畸形。与控制相比,在处理的胚胎中观察到延迟的孵化和凝固。总的来说,这项研究为了解混合金属氧化物(MMO)阳极对使用电化学氧化降解兽用抗生素污染的水和废水源的影响奠定了基础。
    Veterinary antibiotics have become an emerging pollutant in water and wastewater sources due to excess usage, toxicity and resistance to traditional water and wastewater treatment. The present study explored the degradation of a model antibiotic- Florfenicol (FF) using electrochemical oxidation (EO) with Ti-RuO2/IrO2 anode. The anode material was characterized using SEM-EDS studies expressing stable structure and optimal interaction of the neighboring metal oxides with each other. The EDS results showed the presence of Ru, Ir, Ti, O and C elements with 6.44%, 2.57%, 9.61%, 52.74% and 28.64% atomic weight percentages, respectively. Optimization studies revealed pH 5, 30 mA cm-2 current density and 0.05 M Na2SO4 for 5 mg L-1 FF achieved 90% TOC removal within 360 min treatment time. The degradation followed pseudo-first order kinetics. LC-Q-TOF-MS studies revealed six predominant byproducts illustrating hydroxylation, deflourination, and dechlorination to be the major degradation mechanisms during the electrochemical oxidation of FF. Ion chromatography studies revealed an increase in Cl-, F- and NO3- ions as treatment time progressed with Cl- decreasing after the initial phase of the treatment. Toxicity studies using Zebrafish (Danio rerio) embryo showed the treated sample to be toxic inducing developmental disorders such as pericardial edema, yolk sac edema, spinal curvature and tail malformation at 96 h post fertilization (hpf). Compared to control, delayed hatching and coagulation were observed in treated embryos. Overall, this study sets the stage for understanding the effect of mixed metal oxide (MMO) anodes on the degradation of veterinary antibiotic-polluted water and wastewater sources using electrochemical oxidation.
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  • 文章类型: Journal Article
    在经济发展和生态承载力的双重约束下,有必要探索更多的技术手段来实现中国的碳中和峰值。植物是陆地和海洋碳汇系统的重要载体,而植物修复也是修复环境污染的科学方法。然而,目前的研究主要集中在植物碳固存的单一方面(包括环境介质中污染物浓度的降低和污染物的降解)或植物污染的减少,不考虑植物污染减少和碳固存的双重好处。为了探究植物的碳中和效应,重点研究了碳中和植物的污染减排和固碳效果及其进展,评价了碳中和植物及其他生物(如动物和土壤微生物)和环境功能材料的污染减排和固碳潜力。碳中性动植物协同耦合的潜在机制,微生物,以及环境功能材料和生态系统在减少污染和碳固存方面的应用也进行了探索。最后,我们对碳中和植物在减少污染和碳汇方面的未来研究提出了建设性的前景。
    Under the dual constraints of economic development and ecological carrying capacity, it is necessary to explore more technical means to achieve carbon neutrality and peak in China. Plants are important carriers of terrestrial and marine carbon sink systems, whereas phytoremediation is also a scientific method to remedy environmental pollution. However, the current studies mostly focus on the single aspect of plant carbon sequestration (including both the reduction of pollutant concentrations in environmental media and degradation of pollutants) or plant pollution reduction, without considering the dual benefits of plant pollution reduction and carbon sequestration. In order to explore the carbon neutral effect of plants, we focused on the pollution reduction and carbon sequestration effect of carbon neutral plants and its progress and evaluated the pollution reduction and carbon sequestration potential of carbon neutral plants and other organisms (such as animals and soil microorganisms) and environmental functional materials. The mechanisms underlying the synergistic coupling of carbon neutral plants and animals, microorganisms, and environmental functional materials and ecosystems in reducing pollution and carbon sequestration were also explored. Finally, we proposed constructive prospects for future research on the effects of carbon neutral plants on pollution reduction and carbon sink.
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  • 文章类型: Journal Article
    铅(Pb)是最常见的城市土壤重金属污染物之一,对人类具有众所周知的毒性。这项孵化研究(2-159d)比较了骨粉(BM)的能力,磷酸氢钾(KP),和三过磷酸钙(TSP),在磷:铅(P:Pb)摩尔比为7.5:1、15:1和22.5:1的情况下,相对于未添加P改良剂的对照土壤,减少了受Pb基涂料污染的土壤中可生物利用的Pb。测量了土壤pH值和Mehlich3生物可利用的Pb和P,它们是孵育时间,P修饰量和类型的函数。XAS在孵育30和159d后评估了Pb形态。在7.5:1和15:1P:Pb摩尔比下,TSP在159d时生物可利用的Pb的最大减少量。与对照土壤相比,7.5:1KP处理是唯一一种生物可利用性Pb显着减少的其他处理。目前尚不清楚为什么较低的磷添加量会导致生物可及性铅的减少,但这强烈表明,P的添加量不是减少生物可及铅的控制因素。这进一步得到支持,因为使用XAS在任何样品中均未检测到Pb-磷酸盐。TSP与其他改良剂的效果最显著的差异是pH的降低。然而,增加TSP添加之间的关系,导致pH值降低和Pb生物可及性降低不一致。与对照土壤相比,22.5:1P:PbTSP处理的pH最低,但并未显着降低生物可利用性Pb。与对照相比,7.5:1和15:1P:PbTSP处理显着降低了生物可利用的Pb,并且pH值明显高于22.5:1P:Pb处理。显然,添加P和土壤pH值对Pb生物可及性的影响需要进一步研究,以破译控制Pb基涂料污染土壤中Pb形态形成的机制。
    Lead (Pb) is one of the most common heavy metal urban soil contaminants with well-known toxicity to humans. This incubation study (2-159 d) compared the ability of bone meal (BM), potassium hydrogen phosphate (KP), and triple superphosphate (TSP), at phosphorus:lead (P:Pb) molar ratios of 7.5:1, 15:1, and 22.5:1, to reduce bioaccessible Pb in soil contaminated by Pb-based paint relative to control soil to which no P amendment was added. Soil pH and Mehlich 3 bioaccessible Pb and P were measured as a function of incubation time and amount and type of P amendment. XAS assessed Pb speciation after 30 and 159 d of incubation. The greatest reductions in bioaccessible Pb at 159 d were measured for TSP at the 7.5:1 and 15:1 P:Pb molar ratios. The 7.5:1 KP treatment was the only other treatment with significant reductions in bioaccessible Pb compared to the control soil. It is unclear why greater reductions of bioaccessible Pb occurred with lower P additions, but it strongly suggests that the amount of P added was not a controlling factor in reducing bioaccessible Pb. This was further supported because Pb-phosphates were not detected in any samples using XAS. The most notable difference in the effect of TSP versus other amendments was the reduction in pH. However, the relationship between increasing TSP additions, resulting in decreasing pH and decreasing Pb bioaccessibility was not consistent. The 22.5:1 P:Pb TSP treatment had the lowest pH but did not significantly reduce bioaccessible Pb compared to the control soil. The 7.5:1 and 15:1 P:Pb TSP treatments significantly reduced bioaccessible Pb relative to the control and had significantly higher pH than the 22.5:1 P:Pb treatment. Clearly, impacts of P additions and soil pH on Pb bioaccessibility require further investigation to decipher mechanisms governing Pb speciation in Pb-based paint contaminated soils.
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  • 文章类型: Journal Article
    生物和非生物压力对各种农业生态系统造成的滋扰仍然是科学博爱的重点领域。然而,新兴的污染物,如微塑料(MP)已经在农业生态系统中施加了额外的尺寸(单独或与其他压力源组合),并不断升级挑战以实现可持续性。MP被认为是持续的人为污染物,由于其独特的化学特性,使自己对腐烂过程无反应,因此引起全球关注。这篇综述已经被理论化,以评估当前的研究趋势(以及可能的差距区域),MP的广泛使用,增强重金属(HMs)的粗糙度,与耕地土壤理化成分的复杂相互作用,在大田作物的可食用部分积累,乳制品,和其他穿透食物网的来源。到目前为止,现有的评论文章针对MP的某个方面,从土壤-水-食物的角度考虑时缺乏总体。总之,已经全面评估了MP对人类健康的不利影响.此外,与MP相关的政策和补救措施的农业-技术-社会-健康前瞻性批判性评估在有影响力的未来研究过程中比其他类似文章更具优势。
    Nuisance imposed by biotic and abiotic stressors on diverse agroecosystems remains an area of focus for the scientific fraternity. However, emerging contaminants such as microplastics (MP) have imposed additional dimension (alone or in combinations with other stressors) in agroecosystems and keep escalating the challenges to achieve sustainability. MP are recognized as persistent anthropogenic contaminants, fetch global attention due to their unique chemical features that keeps themselves unresponsive to the decaying process. This review has been theorized to assess the current research trends (along with possible gap areas), widespread use of MP, enhancement of the harshness of heavy metals (HMs), complex interactions with physico-chemical constituents of arable soil, accumulation in the edible parts of field crops, dairy products, and other sources to penetrate the food web. So far, the available review articles are oriented to a certain aspect of MP and lack a totality when considered from in soil-water-food perspective. In short, a comprehensive perspective of the adverse effects of MP on human health has been assessed. Moreover, an agro-techno-socio-health prospective-oriented critical assessment of policies and remedial measures linked with MP has provided an extra edge over other similar articles in influential future courses of research.
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  • 文章类型: Journal Article
    超过一半的社区大学生在数学方面没有达到大学准备标准。发展教育(dev-ed)旨在帮助学生获得知识和技能,以在大学水平的数学中取得成功,但受低升学率困扰。我们研究了加速发展数学课程的模型的影响,以便学生可以在1年内完成他们的学习计划中的开发和大学数学课程。使用德克萨斯州的数据和倾向得分匹配方法,我们测试了该模型对几个大学里程碑的影响。结果表明,加速模型中的学生比传统数学中的学生更有可能在第一年坚持和积累大学水平的学分。三年后,参与加速模式和重要的大学里程碑之间有很强的积极关系,比如大学数学课程完成度和累计大学学分。
    More than half of community college students fail to meet college-readiness standards in math. Developmental education (dev-ed) aims to help students acquire the knowledge and skills to succeed in college-level math but is plagued with low rates of advancement. We examined the impact of a model that accelerates developmental math coursework so that students can complete dev-ed and college math courses in their programs of study within 1 year. Using data from Texas and a propensity score matching approach, we tested the impact of the model on several college milestones. Results suggest that students in the accelerated model were more likely to persist and accumulate college-level credits during the 1st year than those in traditional dev-ed math. After 3 years, there was a strong positive relationship between participation in the accelerated model and important college milestones, like college math course completion and total accumulated college-level credits.
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