利用生物炭负载微生物修复石油烃-镉复合污染土壤

自四川省长宁某石油烃-重金属镉复合污染土壤中,筛选出1株具有重金属镉(Cd)抗性和石油烃降解能力的菌株,采用吸附法将菌株固定于玉米芯生物炭上制备成固定化微生物,并探讨固定化微生物技术(IMT)对土壤石油烃的降解效率以及重金属固定化效果.鉴定结果表明,成功筛选出的具有Cd抗性的石油烃降解菌经鉴定属于柠檬酸杆菌属(Citr...     

污染负荷及植被生物量变化对缓冲带污染物净化效果的影响

模拟上海地区农业面源污染和降雨特征,进行缓冲带污染物净化效果和植被生物量监测试验研究。结果表明：植被缓冲带对径流污染物质的净化效果明显高于空白对照,百慕大缓冲带SS截留率最高,达到74％;白花三叶草对TN、TP的净化效果最好,去除率分别为28％和25％;百慕大和白花三叶草生物量最大,栽种当年9月份,两者地上部分的生物量鲜重分别达到了6.14和6.49 kg/m²,百慕大生长速度最快,当年9月份生物量几乎达到5月份的6倍;植被生物量增长明显提高了缓冲带截留径流污染物的效果,缓冲带SS截留率与生物量成显著线性相关,而污染负荷变化对缓冲带污染物净化效果的影响很小,明显弱于植被种类和生物量的变化。     

丁草胺与镉复合污染对土壤呼吸强度的影响

研究了除草剂丁草胺和重金属镉(Cd)复合污染对两种土壤呼吸强度的影响及其随时间的动态变化.结果表明,单一污染中,丁草胺和Cd对土壤呼吸强度的影响,随土样不同而异,随农药浓度及培养时间的变化而变化;复合污染中,两种土样的复合污染对土壤呼吸强度的影响存在明显的交互作用,与单一污染相比,对土壤呼吸强度的影响依次表现为:丁草胺＞Cd与丁草胺复合污染＞Cd.建立了丁草胺和Cd在不同浓度配比下对土壤呼吸强度影响的多元回归分析模型.     

堆肥+零价铁可渗透反应墙修复黄土高原地下水中铬铅复合污染

为了研究堆肥+零价铁混合可渗透反应墙（PRB）修复黄土高原地下水中铬铅复合污染的可行性,分别用堆肥、零价铁、堆肥+ 零价铁、堆肥+ 零价铁+活性炭为反应介质,通过模拟柱实验考察PRB修复铬铅复合污染黄土高原地下水的效果。结果表明,在实验进行30 d后当反应柱1和2对六价铬的去除率接近于零,而且对二价铅的去除率迅速下降时,反应柱3对2种污染物仍保持较高的去除率;反应介质质量比为10：2：1的反应柱4和质量比为10：1：2的反应柱5对污染物的去除效果均优于质量比为10：1：1的反应柱3;反应50 d后,添加活性炭的反应柱6对2种污染物的去除率仍在90%。这说明使用堆肥+零价铁混合可渗透反应墙修复黄土高原地下水中铬铅复合污染是可行的;且以堆肥+零价铁作为介质的反应柱去除效果优于单独以堆肥或铁粉为介质的反应柱;增加铁粉或堆肥的用量有利于铬铅复合污染的去除;且同时添加活性炭更有助于污染物的去除。     

复合微生物菌剂对污泥堆肥的作用效果研究

为了研究复合微生物菌剂对污泥堆肥的作用效果,以消化污泥、锯末和回流堆肥为原料,接种不同剂量(0、0.2%、0.5%)的复合微生物菌剂进行室外露天堆肥,分析了温度、含水率、pH值、全碳(TC)、全氮(TN)、种子发芽指数(germination index,GI)的动态变化,结果表明:各堆体温度保持在50℃以上的时间均超过7 d,满足堆肥卫生标准;接种复合微生物菌剂的堆体升温速率和温度最高值均大于未接种堆体,接种复合微生物菌剂有利于增加堆体水分散失量,加快堆体有机质降解速度,降低堆体氮的损失量,提高GI值;其中微生物菌剂接种量为0.5%的堆体,接种处理对水分散失、氮损失的控制和GI值的增加效果较明显.     

耐铅微生物的筛选及其吸附能力的初步研究

通过向土壤中添加一定量的铅来驯化土壤微生物,然后利用一系列不同铅浓度的PDA培养基分离耐铅微生物,结果获得一株耐300mg／L铅的细菌Pb—R-1和二株分别耐750mtg／L和900mg／L铅的真菌Pb—R-2和Pb—R-3,通过鉴定得知,Pb—R-2菌株为曲霉,Pb—R-3菌株为青霉;不同成分培养基（有铅或无铅）传代培养实验表明,3个菌株有稳定的耐铅遗传性;通过液体悬浮培养获得：Pb—R-1、Pb—R-2和Pb—R-3对Pb^2＋的吸附率依次为35．5％、75．5％和48．2％。采用3个菌株浸种试验表明,小麦的发芽率几乎不受影响,其它的受影响差别较大。因此,用Pb—R-2吸附小麦土壤中的铅,具有潜在的应用价值。     

高羊茅对微生物强化修复石油污染土壤影响的研究

进行了石油污染土壤在外源微生物菌剂和高羊茅协调作用下的强化修复试验,对外源微生物菌剂在不同植被条件下的去除特征进行了分析.分别进行了没有植物、高羊茅草坪、高羊茅草种新育草坪3种不同情况下的降解试验.结果表明,微生物菌剂对石油污染土壤有着良好的降解效果,去除率为36%～43%,而没有微生物菌剂和植被作用下的对照组的去除率仅为5.74%～6.0%;高羊茅草坪能够提高微生物进一步降解的能力,在直接铺草坪的情况下,去除率可以达到51%～62%;在播种高羊茅草种,形成新嫩草坪的情况下,去除率为48%～54%.结果表明,在直接铺高羊茅草坪条件下,微生物菌剂的强化分解作用可以提高41.6%～44.2%,在新嫩草坪作用下能够提高27.9%～30.6%,可以认为高羊茅草坪对于提高微生物菌剂的强化分解有一定的促进作用.在试验过程中还对不同修复的土壤pH值变化特性进行了分析.     

石油污染土壤的植物与微生物修复技术

石油污染土壤的生物修复技术具有成本低、简便高效、对环境影响小等优点,正逐步成为石油污染治理研究的热点领域,具有广阔的发展前景.介绍了我国的石油污染概况及生物修复技术在石油污染治理中的应用,重点对石油污染土壤的微生物修复、植物修复、植物一微生物联合修复技术的研究进展及各自的优点、局限性进行了综述,并提出了石油污染土壤生物修复技术研究的重点领域.     

铅冶炼污染防治技术评价指标体系的构建

从铅冶炼工艺入手,根据铅冶炼整个过程中的重污染环节,对铅冶炼污染防治技术评价指标体系的构建进行了探讨.首先根据铅冶炼过程中的重污染环节,采用生命周期法(LCA)确定了从备料至铅锭产出的全过程的评价范围,在此基础上进行了污染物质流分析.再结合污染物质流分析结果,提出了铅冶炼污染防控的关键工序,包括冶炼工序、“三废”治理工序.最后,以《有色金属产业调整和振兴规划》、《铅锌行业准入条件》、《清洁生产标准》、《铅、锌工业污染物排放标准》等为依据,在遵循针对性、客观性等原则下,构建了目标层、子目标层、指标层三层结构的铅冶炼污染防治技术评价指标体系,目标层为铅冶炼污染防治技术水平,子目标层包括环境管理、冶炼工艺与装备、烟气制酸程度、“三废”处理情况、余热利用情况、周边环境整治情况等六大污染防控因子,指标层包含24项具体指标,并给出了每个指标的明确涵义或计算方法.     

不同活化剂对镉、铅单一及复合污染土壤的修复效果影响

选取柠檬酸(CA)、木醋液(WV)、聚天冬氨酸(PASP)、羟基乙叉二磷酸(HEDP)和FeCl_3作为活化剂,以镉、铅单一和复合污染土壤为研究对象,采用振荡淋洗法结合形态分析技术研究活化剂对重金属污染土壤的修复效果。结果表明:(1)重金属单一污染时,5种活化剂对镉、铅均有一定的淋出效果,淋出效率均随活化剂浓度的增大而增大。活化剂通过淋洗实验主要淋出酸溶态和可还原态重金属。(2)重金属复合污染时,金属离子间的竞争作用会不同程度地影响重金属在土壤中的存在形态,进而影响重金属的淋出效率,多数情况下,铅的存在会促进镉的淋出,但镉的存在会抑制土壤铅的释放。     

Sorption behavior of bensulfuron-methyl on andisols and ultisols volcanic ash-derived soils: Contribution of humic fractions and mineral-organic complexes

Bensulfuron-methyl sorption was studied in Andisol and Ultisol soils in view of their characteristic physical and chemical properties, presenting acidic pH and variable charge. Humic and fulvic acids (HA and FA) and humin (HUM) contributions were established. Sorption was studied by using two synthetic sorbents, an aluminum-silicate with iron oxide coverage and the same sorbent coated with humic acid. Freundlich model described Bensulfuron-methyl behavior in all sorbents (R² 0.969-0.998). K_f for soils (8.3-20.7 μg^1−1/n mL^1/n g⁻¹) were higher than those reported in the literature. Organic matter, halloysite or kaolinite, and specific surface area contributed to the global process. The highest K_f for HA, FA and HUM were 539.5, 82.9, and 98.7 μg^1−1/n mL^1/n g⁻¹. Model sorbents described the participation of variable charge materials with high adsorption capacity. The constant capacitance model was used to assess effects of Bensulfuron-methyl adsorption on the distribution of SOH, SOH₂⁺ and SO⁻ sites of sorbents.     

Lead (Pb) isotopic fingerprinting and its applications in lead pollution studies in China: A review

As the most widely scattered toxic metal in the world, the sources of lead (Pb) observed in contamination investigation are often difficult to identify. This review presents an overview of the principles, analysis, and applications of Pb isotopic fingerprinting in tracing the origins and transport pathways of Pb in the environment. It also summarizes the history and current status of lead pollution in China, and illustrates the power of Pb isotopic fingerprinting with examples of its recent applications in investigating the effectiveness of leaded gasoline phase-out on atmospheric lead pollution, and the sources of Pb found in various environmental media (plants, sediments, and aquatic organisms) in China. The limitations of Pb isotopic fingerprinting technique are discussed and a perspective on its development is also presented. Further methodological developments and more widespread instrument availability are expected to make isotopic fingerprinting one of the key tools in lead pollution investigation.     

生物质对水体油污染吸附处理的研究进展

随着石油资源的开发与利用,水体油污染日益严重,寻求价廉、高效、环保的除油方法引起人们的关注,其中吸附法除油效率高,应用范围广,具有很好的发展前景。介绍了水体油污染现状、危害、处理方法,比较了不同类型吸油材料的吸油特性,提出生物质是兼具价廉、环保等多重优点的高效吸油材料。基于此,对生物质吸油材料的选择标准及除油影响因素进行了总结,介绍了常用的吸油机制微观分析方法,并对生物质除油的研究前景进行展望。     

Effects of lead contamination on the growth of lythrum salicaria (purple loosestrife)

The ability of individual species to tolerate or accumulate heavy metal pollutants has been investigated widely. Although invasive species may become established more easily in disturbed environments, relatively little is known about how an ability to tolerate pollutants might give invasive species a competitive advantage. This study is part of a series of experiments investigating native and invasive species interactions with chemical pollution and other forms of disturbance. The purpose of this experiment was to investigate the effects of lead on the growth of Lythrum salicaria. We exposed plants to different concentrations of lead and measured different growth parameters, such as biomass, length, leaf number, and biomass allocation to roots. For most measures, plants grown in lead-free conditions were larger than plants exposed to lead. Plants in the low (500 mg/l) and medium (1,000 mg/l) lead treatments did not differ from each other, while plants in the high (2,000 mg/l) lead treatment were significantly smaller. However, the biomass allocation to roots was not significantly different among treatments. Although their growth is affected, individuals of Lythrum salicaria demonstrated tolerance to lead contamination, which may aid in their colonization in lead-polluted wetlands.     

生物质快速热裂解主要参数对生物油产率的影响

以松木木屑为原料,在自制的小型流化床上,开展了生物质热裂解温度、生物质粒径和进料速率对生物油产率的影响实验研究.结果表明,在热裂解温度分别为450、475、500、525和550℃条件下,当热裂解温度为500℃时,生物油产率最高,平均产率达到53.33%（质量百分比）.反应温度越高,炭产量越低,不可冷凝气体产量越高,气体发热值越高;粒径＜1 mm的生物质其粒径对生物油产率影响不大;生物质进料速率增加时,生物油产率增加.本研究为生物能的利用提供了新的途径.     

生物质快速热裂解主要参数对生物油产率的影响

以松木木屑为原料,在自制的小型流化床上,开展了生物质热裂解温度、生物质粒径和进料速率对生物油产率的影响实验研究.结果表明,在热裂解温度分别为450、475、500、525和550℃条件下,当热裂解温度为500℃时,生物油产率最高,平均产率达到53.33%(质量百分比).反应温度越高,炭产量越低,不可冷凝气体产量越高,气体发热值越高;粒径＜1 mm的生物质其粒径对生物油产率影响不大;生物质进料速率增加时,生物油产率增加.本研究为生物能的利用提供了新的途径.     

生物质利用方式对富营养水体中碳氮磷含量及其比例的影响

生物质常被添加至富营养水体中以调节碳氮比(C/N),促进脱氮,但不清楚生物质的粒径和投加方式对富营养水体中营养物质浓度和比例的影响。通过机械粉碎制得20~40、40~80、80~160目稻壳颗粒,并选取直接投加和无纺布包裹投加2种投加形式,以不添加稻壳或无纺布包裹砖块作为对照组。以超纯水为水样研究不同粒径和投加方式下稻壳的3 d碳氮磷释放特性;以成都市府河下游河段水样为研究对象,考察了不同粒径和投加方式下稻壳的21 d静态脱氮特性。结果表明,在超纯水中,稻壳释放出COD_Mn(5.5~16.5 mg·L⁻¹)、TP(0.18~0.45 mg·L⁻¹)、TN(0.39~0.95 mg·L⁻¹)、COD_Mn/TN(8.5~19.7)、COD_Mn/TP(27.9~37.5),前四者均呈现出80~160目>40~80目>20~40目的规律,仅COD_Mn和COD_Mn/TN呈现直接投加>无纺布包裹投加的规律。在静态脱氮实验中,21 d后,添加了稻壳的水样COD_Mn含量由28.1 mg上升至71.7~143.0 mg,TP含量由1.2 mg下降至0.2~0.5 mg,COD_Mn/TN由0.9上升至8.5~16.5,COD_Mn/TP由24.2上升至170以上,这4个参数的变化情况与稻壳的碳氮磷释放规律相同;TN含量由30.04 mg下降至7.64~8.68 mg,低于对照组(13.2~13.9 mg),但粒径和投加方式仅对实验初期水中氮的存在形态有影响。粒径决定稻壳的比表面积,投加方式决定稻壳的间隙,并影响微生物的附着效果,进而影响稻壳的碳氮磷释放效果。在实际应用时可根据情况,采用不同的生物质粒径和投加方式,以调节水中营养物质浓度和比例。     

Food chain transfer of cadmium and lead to cattle in a lead–zinc smelter in Guizhou, China

Cadmium (Cd) and Lead (Pb) are environmental pollutants. Environmental samples and bovine tissues were collected from the areas around a lead–zinc smelter in Guizhou, China for Cd, Pb, zinc (Zn) and copper (Cu) analysis. Cd in soil (10 mg/kg) and feed (6.6 mg/kg) from the polluted areas was 10 times higher than the Chinese Standards, resulting in higher Cd in bovine kidney (38 mg/kg) and liver (2.5 mg/kg). Pb in feed (132 mg/kg) from the polluted area was much higher than unpolluted areas, causing higher Pb levels in bovine tissues. Environmental Zn was elevated, but bovine tissue Zn was normal. Cu in bovine liver decreased with increased Cd and Pb. Metals in drinking water and in bovine muscle were within the Standard range. Thus, in the areas of this lead–zinc smelter, the environment has been contaminated with Cd and Pb, which has been transferred to cattle through the food chain.     

Effects of inorganic lead on Western fence lizards (Sceloporus occidentalis)

Although anthropogenic pollutants are thought to threaten reptilian species, there are few toxicity studies on reptiles. We evaluated the toxicity of Pb as lead acetate to the Western fence lizard (Sceloporus occidentalis). The acute lethal dose and sub-acute (14-day) toxicity studies were used to narrow exposure concentrations for a sub-chronic (60-day) study. In the sub-chronic study, adult and juvenile male lizards were dosed via gavage with 0, 1, 10 and 20 mg Pb/kg-bw/day. Mortality was limited and occurred only at the highest dose (20 mg Pb/kg-bw/d). There were statistically significant sub-lethal effects of 10 and 20 mg Pb/kg-bw/d on body weight, cricket consumption, organ weight, hematological parameters and post-dose behaviors. Of these, Pb-induced changes in body weight are most useful for ecological risk assessment because it is linked to fitness in wild lizard populations. The Western fence lizard is a useful model for reptilian toxicity studies.