污染土壤电动修复正交试验研究

通过正交试验研究了电动修复Cr6 污染高岭土过程中施加电压、处理时间、含水率、阴极电解产生OH一控制4个因素对污染物去除率和电能消耗的影响.试验选用重铬酸钾作为污染物,配制高岭土中Cr6 初始含量为500mg·kg-1.试验结果表明:阴极pH控制对cr6 去除率影响最大,其次为施加电压和处理时间,含水率影响最小;电压对电能消耗的影响最大,其次为时间和含水率,阴极pH控制对电能消耗影响最小.分析表明控制阴极pH是提高污染土壤电动修复效率的优先选择.     

重金属-有机污染物复合污染土壤修复工程实例

采用异位化学氧化和稳定化技术联合修复重金属-有机污染物复合污染土壤,污染土壤中重金属类和有机物共计16项污染物指标超出《上海市场地土壤环境健康风险评估筛选值(试行)》中非敏感用地标准,土方量共计1.64×105m3。项目于2018年10月通过环保验收,修复后的场地土壤质量满足《上海市场地土壤环境健康风险评估筛选值(试行)》和《地下水质量标准》Ⅳ类标准。对该工程的场地布置、开挖清运、土方筛分、固废分类合规处置、化学氧化及稳定化技术等关键环节进行了介绍。     

镉污染土壤植物萃取技术的研究进展

植物萃取是指在受重金属污染的土壤上连续的种植专性植物并收割植物茎叶作离地处理 ,以降低土壤中的重金属浓度的新兴技术。利用此方法对镉污染土壤进行原位修复具有成本低、环境可持续性的优点。综述了近年来这一领域内的研究进展及其商业应用的可行性分析 ,并展望了此技术在我国的应用前景。     

改性废弃稀土抛光粉应急修复砷污染土壤研究

以废弃稀土抛光粉为原料制备砷钝化剂对漳州、龙岩和三明的硫酸厂废渣堆放区域采集的砷污染土壤进行应急修复。采用体外模拟法检测污染土壤中砷对人体的生物有效性,从而评价钝化剂对砷污染土壤的修复效果。结果表明:3处土壤样品的砷对儿童健康的相对风险系数为1.9~7.1;投加2%质量比的砷钝化剂1~3 d后,可使其对儿童健康的相对风险系数降低至世界卫生组织人体健康风险警戒线以下。     

固定-可摘联合修复咬合重建

目的：探讨固定一可摘联合修复在咬合重建治疗中应用效果。方法：临床采集牙列重度磨耗伴咬合丧失的例病例12,采用固定一可摘联合修复方法实施牙列重度磨耗咬合重建治疗。咬舍重建采用序列治疗的方法,确定治疗计划进行完善的牙周、牙体、牙髓治疗。采用过渡性合垫式义齿恢复颌位关系,戴用3个月后固定一可摘义齿永久修复,恢复正确的颔位和咬合关系。结果：咬合重建后患者外形容貌、发音、咀嚼功能评价良好,咬合关系和颞下颌关节紊乱（TMD）症状显著改善。结论：采用固定一可摘联合修复治疗牙列重度磨耗,进行咬舍重建的临床效果较好,患者满意度高,其TMD症状有明显改善。     

大气污染植物修复的研究进展

利用植物修复大气污染是一种经济有效、且易被社会接受的环境污染修复方式。详细地阐述了大气污染植物净化的机理以及近年来国内外利用植物修复大气污染的研究成果,并对其未来发展进行了一定程度的探讨。     

土壤中锌镉复合污染及其植物效应研究进展

由于化学性质相似,锌、镉在自然界总是伴生、伴存而造成伴随危害,经土壤到植物,继而通过食物链危害人类健康。综述了近年来锌、镉在土壤———植物系统中的迁移转化,土壤锌、镉的吸附解吸与生物有效性,以及植物对锌、镉胁迫的反应及毒性研究进展。     

固定-活动联合修复用于牙列缺失修复中的临床观察

目的探讨固定-活动联合修复在牙列缺失修复中的应用。方法选择牙列缺失患者82例为研究对象,根据修复方法的不同分为两组。对照组41例患者接受传统活动义齿修复,观察组41例患者接受固定-活动联合修复,比较两组患者的修复效果及满意率。结果修复前,两组患者的咀嚼功能、固位功能及舒适度、美观度等各项评分比较,差异无统计学意义(P>0.05);修复后,两组患者的各项评分均有改善,且观察组的各项评分均显著高于对照组,差异有统计学意义(P<0.05)。观察组患者的满意率为97.56%,显著高于对照组的78.05%(P<0.05)。结论固定-活动联合修复牙列缺损更能满足患者需求,有助于提高固位功能及咀嚼功能,具有较高的舒适度及美观度,患者满意率高,值得临床推广。     

重金属污染土壤生物修复技术研究现状

土壤是生态环境的重要组成部分,与人类的生存和健康密切相关。目前,生物修复技术已开始成为土壤污染修复的主要处理技术。该文系统介绍了重金属污染土壤生物修复的概念、生物修复特点及其机制、类型,重点论述了植物、微生物、动物对重金属污染土壤的修复技术方面的研究进展,并在此基础上提出了一些见解和看法,为今后该方面的研究提供参考。     

Fate and stability of 14C-labeled 2,4,6-trinitrotoluene in contaminated soil following microbial bioremediation processes

Biological treatment of 2,4,6-trinitrotoluene (TNT) in soil rarely results in complete mineralization of the parent compound. More often, the largest proportion of the TNT carbon is incorporated into the soil organic matrix. Therefore, we evaluated the stability of nonextractable residues from various bioremediation processes of 14C-TNT in soils. The extractable amounts of the residual radioactivity varied between 7 and 33% and thus the nonextractable amount between 93 and 67% (3-15% in fulvic acids, 26-46% in humic acids, and 27-44% in the humin fraction). The residue-containing soils were analyzed for the release of radioactivity after treatment by physical (freeze and thaw, grinding of soil, and steam extraction), chemical (acid rain and addition of metal complexing agent), and biological methods (addition of compost, white rot fungi, radical-generating enzymes, and germination of plants). Freeze and thaw treatment and grinding of the soil did not alter the partitioning of the label significantly. Steam extraction and acid rain extraction increased the water extractability to 11 to 29% and to 51.6% in the native TNT-contaminated soil. The addition of ethylenediamine-tetraacetate (EDTA) increased the extractability from 7 to 12%. After biological treatment, only slightly increased extractability (<10%) was observed. No increase of extractable TNT or known metabolites was observed with any of the treatments. Thus, under the treatment conditions applied in this study, the residues formed during microbial transformation of TNT may be biogenic residues with low mobilization potential and low hazardous impact.     

中国粮食中杂色曲霉素污染状况调查及分析

用间接竞争酶联免疫分析法 (IC ELISA)检测我国粮食中杂色曲霉素 (ST)。样品取自东北、西北、华东、华中和西南五大地区 12个省市的小麦、玉米和大米样品共 15 80份。结果三种粮食中杂色曲霉素平均污染量分别为 6 8 9、32 2和 13 9ug kg。杂色曲霉素污染率分别为 98%、89%和 72 %。污染量及污染率大小为小麦 >玉米 >大米 (P <0 0 1)。按地区统计三种粮食中杂色曲霉素污染量华东和西北高于东北、华中和西南 (P <0 0 1)     

毒死蜱在韭菜和土壤中最终残留的研究

为了全面准确地评价毒死蜱及其制剂在韭菜园中使用后的生态环境安全性,指导毒死蜱及其制剂的科学合理使用,有效地保护农业生态环境,确保农产品质量安全;本文借助气相色谱检测技术,通过田间试验研究毒死蜱在韭菜和土壤中的最终残留。实验结果表明,在韭菜生长期按常规用药剂量和高剂量喷施毒死蜱,毒死蜱最终残留表现为：韭菜〈土壤,施药后3d、7d、14d后韭菜中的毒死蜱最终残留量均小于0.1mg/kg,符合GB18406.1-2001《农产品安全质量无公害蔬菜安全要求》（Safety qualification for agricultural product-Safety requirements for non-environmental pollution vegetable）规定的最大残留量1.0mg/kg和GB2763-2005《食品中农药最大残留限量》规定的0.1mg/kg。     

Short-term ecological risks of depositing contaminated sediment on arable soil

Sediments act as sinks of suspended material from surface water. Dredging of regional waters and subsequent disposal of the sediment on soil may lead to contamination of the soil, in some cases resulting in exceedance of soil quality standards. Soil quality standards are based on total concentrations. Total levels, however, do not always give an indication of adverse effects in soil ecosystems. Instead, truly bioavailable concentrations should be used as indicators. In this study we aim to test a set of suited indicators. We carried out partition and accumulation assays with metals and polycyclic aromatic hydrocarbons (PAHs) in soils and mixtures of soil and sediment, as well as a limited number of toxicity bioassays. We also investigated the rate of disappearance of PAHs from mixtures of sediments and soils. The experiments confirm that total levels indeed are not indicative of truly occurring toxic effects: mixing of highly contaminated sediments with soil hardly gave rise to either additional accumulation of metals and PAHs or excess toxicity. This indicates that the bioavailability of the metals and PAHs present in the sediment is limited. This general finding is confirmed by the low rate of disappearance of PAHs from the mixtures. It is concluded that inclusion of the aspects of bioavailability, mixture toxicity, and degradation, in the way described in this report, will solve the major limitations of the current methodology of classification of contaminated sediments.     

不同污水中细菌多样性DGGE检测

目的 比较工业、农业和生活污染源河道内细菌群落的多样性, 探讨环境与细菌群落多样性关系, 为修复水环境技术提供理论依据。方法 采集浙江省杭州市未污染的虎跑山泉水和3个不同污染源的水样共70份, 用传统微生物平板培养和变性梯度凝胶电泳(DGGE)技术分析不同水体细菌群落的多样性差异。结果 未被污染的虎跑山泉水pH最小, 为7.25, 其余受到污染的水体pH均>7.4, 滨文河的pH最高, 达8.04;浦沿化工厂河道中存在可培养的细菌最多, 达到821 CFU/mL, 其次为萧山养牛河道, 虎跑最低仅8 CFU/mL, 其细菌总数与pH密切相关;6种受污染的水中均存在大肠埃希菌和葡萄球菌, 生活污水中未检测到沙门菌, 化工污水中未检测到粪链球菌;变性梯度凝胶电泳结果表明, 受污染的水中主要有变形菌门(23条带, 71.9%)、放线菌门(8条带, 25%)和厚壁菌门(1条带, 3.9%), 变形菌门是绝对的优势菌群;不同污染源影响的水中均有特异性细菌条带T5(uncultured bacterium clone C-84, HQ860591)和T7(uncultured rhodocyclaceae bacterium clone D7N55, KC006201), 隶属于β^-变形菌, 只在受化工污染的河水中检测到;而受生活污水污染的河水中特有条带T3和T4均为γ-变形菌的气单胞菌属Aeromona;T10、T29和T30为受畜牧养殖场污水影响的河水中所特有, 均隶属于放线菌门Gordonibacter属。结论 不同的污染直接影响水的pH及细菌群落分布, 且污水中致病菌也存在差异。     

三聚氰胺污染奶粉致儿科泌尿系统结石的分析

目的探讨儿童食用三聚氰胺污染奶粉致泌尿结石的临床诊疗特点。方法选取该院2008年9月—2009年1月收治的泌尿系统结石患儿46例,对其进行回顾性分析,比较碱化尿液、内科补液治疗前后患儿肾结石的变化。结果平均住院15d后对46例患儿复查肾脏超未见结石者25例(54.34%),结石比入院前缩小者19例(41.3%),无明显变化者2例(4.3%)。结论三聚氰胺污染奶粉引起泌尿系统结石以3个月~2岁的患儿居多,这种原因引起的结石要比其他性质的结石密度低,结构比较松散,较易排出,临床实践证明,内科排石治疗效果要远远好于其他性质的结石。     

Control of chemical risks during the treatment of soil contaminated with chlorophenol, creosote and copper-chrome-arsenic-wood preservatives

BACKGROUND: Exposure to chemicals in polluted soil was studied during the remediation of four polluted sites. They are sawmill areas contaminated with chlorophenols and polychlorinated dibenzo-p-dioxins and furanes (PCDD/F), wood impregnating plants contaminated with polycyclic aromatic hydrocarbons (PAH) from creosote oil, old gas works area contaminated with PAH, and a wood impregnation plant contaminated with copper-chromium-arsenic (CCA) preservative. METHODS: The exposure levels were determined by both air and biological monitoring. RESULTS: Air monitoring showed that the exposure levels were generally well below the current occupational exposure limits. The calculations indicated, however, that the lowest acceptable daily intake value recommended for PCDD/F by the U.S. Environmental Protection Agency was exceeded. Chlorophenol exposure was generally low. Exposure to volatile PAH was 0.038-0.884 mg/m(3) and that to particulate PAH was 0.004-0.183 mg/m(3). The biomonitoring results (urinary 1-pyrenol) suggested that some exposure occurs, probably through the contamination of hands or skin absorption. At the sites contaminated with CCA salts, no exposure limits were exceeded. CONCLUSIONS: The results generally suggest that the exposure of cleanup workers is generally below the current occupational exposure limits but that short-term high exposure cannot be excluded. There was also some indication of poor skin protection, which should be improved when soil contaminated with PAH and creosote oil is handled.     

Influence of industrial pollution source on soil animal community structure

Soil animals are an important constituent part of the agroecosystem. The pollution of the agrofields in the major industrial districts in the centre of Hunan Province is mainly caused by the accumulation of poisonous substances of heavy metals in soil. A total of 31 varieties of soil animals, which can be divided into 11 classes belonging to five phyla, have been collected through investigations. As pollution degree increases, soil animals decrease in variety and quantity. The density of soil animals has much to do with the concentration of such heavy metal elements as Hg, Cd, Zn, Cu, As and Pb in soil; this has been proved in simulated experiments with soil pollution.