铜锌复合胁迫下禾本科观赏草的富集、转运效应评价

研究禾本科观赏草在土壤重金属铜、锌复合污染下的富集、转运效应,筛选出耐性品种,为挖掘超富集植物及推动利用植物修复铜、锌污染环境提供参考依据。以9种常见禾本科观赏草作为试验植材,设置5个胁迫梯度,采用盆栽控制法,探究供试观赏草体内铜、锌含量分布状况并分析其对铜、锌的富集能力与转运特征。结果表明,不同供试观赏草吸收重金属铜、锌的能力存在差异;不同部位吸收重金属铜、锌的能力亦差异显著,供试观赏草地上部吸收锌的能力强于地下部,而地下部吸收铜的能力强于地上部。供试观赏草富集、转移锌的能力均强于铜,在锌富集系数、转运系数方面高于铜。采用隶属函数法及Q型聚类分析法,当相对距离为7.5时,可将供试观赏草划分为高、中、低铜锌积累型3类,丽色画眉草、细叶芒综合表现最强且属于高铜锌积累型。

铜锌复合胁迫对菜薹种子萌发、幼苗生长及子叶生理代谢的影响

【目的】研究铜锌复合胁迫对菜薹种子萌发、幼苗生长及子叶生理代谢的影响,为探索菜薹生长发育的耐铜锌范围提供参考。【方法】以菜薹为试验材料,采用单因素随机设计,通过种子萌发试验研究铜锌复合胁迫处理(Cu^(2+)和Zn^(2+)的8个复合浓度分别为0 mmol/L+0 mmol/L、0.20 mmol/L+0.17 mmol/L、0.40 mmol/L+0.34 mmol/L、0.80 mmol/L+0.68 mmol/L、1.20 mmol/L+1.02 mmol/L、1.60 mmol/L+1.36 mmol/L、2.00 mmol/L+1.70 mmol/L和2.40 mmol/L+2.04 mmol/L)对菜薹种子萌发、幼苗生长等指标的影响。菜薹子叶中的SOD活性、CAT活性、可溶性糖、可溶性蛋白质和脯氨酸的含量均随铜锌复合胁迫的增加呈先增后减的趋势,均以处理T4 (0.80 mmol/L Cu^(2+)+0.68 mmol/L Zn^(2+))的最大,其值分别为30.76 U/(g·min)、327.81 U/(g·min)、11.24 nmol/g、15.46 mg/g、452.96μg/g;MDA含量、氧负离子产生速率(O2–)呈先减后增的趋势,以处理T4 (0.80 mmol/L Cu^(2+)+0.68 mmol/L Zn^(2+))的最小,其值分别为15.17 nmol/g和17.86 nmol/(g·min);POD活性和相对电导率呈上升趋势;发芽率、苗高、最长根长、单株鲜重和子叶光合色素含量均呈下降的趋势,均以处理T1(CK)的最大,其值分别为68.00%、1.64 cm、2.99 cm、18.32 mg、0.79 mg/g、0.20 mg/g、0.99 mg/g、0.19 mg/g。【结论】在受到铜锌复合胁迫时,菜薹种子萌发和幼苗生长受到抑制,但同时菜薹对较低的铜锌复合胁迫(0.80 mmol/L Cu^(2+)+0.68 mmol/L Zn^(2+))表现出一定的耐性。

方解石对复合重金属污染土壤的修复研究

通过在人工配置的复合铜铅锌重金属污染土壤中添加不同比例的方解石粉,开展原位钝化修复试验,研究不同比例不同修复时间(30d、60d和90d),方解石对该复合污染土壤的修复效果。结果表明:方解石浓度增加及培养周期的延长对供试土壤pH无显著影响;方解石粉对供试土壤重金属有一定修复效果。相同培养周期内,土壤可提取态重金属含量并不随方解石剂量增加而显著变化;随培养周期延长,修复效果逐渐增强。培养30d时,1%的添加剂量修复效果较好;培养60d时,2%的修复效果较好;培养90d时,1%和2%的修复效果均有所增加,但均小于1.5%的修复效果。就不同重金属而言,培养30~60d时,各处理组方解石添加对供试土壤3种可提取态重金属修复效果依次为Pb>Cu>Zn;培养90d时,修复效果为Cu>Pb>Zn。综上,后期采用方解石进行重金属污染原位修复时,最适添加剂量为1.5%(质量比,风干土计),最佳修复时间≥90d。

铜锌超标的城镇污泥在大规模条垛式堆肥过程中重金属变化

采用技术成熟的条垛式堆肥技术对来自广州市南沙区(以下称N区)和东莞市市区(以下称D区)铜、锌污染超标的城镇污泥进行堆肥处理,对堆肥过程中的重金属浓度随时间的变化规律进行研究。结果表明:N区污泥中,Cu、Zn、Cd、Cr、As含量分别下降了93.5%、60.2%、49.7%、93.0%、77.0%;D区污泥中,Cu、Zn、Cd、Cr、As含量分别下降了33.6%、40.8%、26.3%、24.2%、29.8%,Hg含量在两区污泥中均有上升,分别为49.1%和2.8%。采用单一试剂(DTPA)浸提法测定了重金属的生物有效性,N区污泥的Cu、Zn、Cd、As、Hg的金属活性系数平均值分别为15.8%、16.5%、25.5%、5.8%、11.7%,金属活性顺序为:Cd>Zn>Cu>Hg>As;Cu、Zn、Cd、As、Hg的金属活性系数平均值分别为19.3%、19.6%、24.3%、8.3%、6.2%,金属活性顺序为:Cd>Zn>Cu>As>Hg,Cr的有效性在两区中均未检测出。经过约20d的二次腐熟后,使堆肥产品中的重金属含量低于原污泥,符合了土地利用污泥污染物控制标准,而且也远低于美国USEPA503标准;同时堆肥也改变了重金属的生物活性,使污染超标的Cu、Zn的生物有效性大大降低。因此经过条垛式堆肥处理可将这两区污泥农林利用。

Effect of Heavy Metals on Phosphorus Retention by Typic Udic Ferrisols: Equilibrium and Kinetics

A study was conducted to examine the effect of heavy metals (Cu,Pb, Zn and Cd in combination or alone) on the equilibrium andkinetics of phosphorus (P) retention in typic udic ferrisols by usingboth equilibrium and flow techniques. Fourteen soil samples withvarying artificial contamination of Cu, Pb, Zn and Cd were prepared.Heavy metal pollution led to increases in retention capacity andmaximum buffering capacity (MBC) of soil P. The rate of P retentionwas also increased and the time to reach equilibrium was advanced byheavy metals addition.

Effect of Heavy Metal Pollution on Potassium Behavior in Typic Udic Ferrisol

The indirect influence of heavy metal contamination of soil on nutrient availability, an important aspect of soil quality, may need to be taken into consideration when determining overall effects of heavy metals. A laboratory experiment was performed to study the effects of combined pollution of Cu, Ph, Zn and Cd on soil K status as indicated by chemical fractions, adsorption-desorption and quantity/intensity (Q/I) relationship of K in a Typic Udic Ferrisol (generally called red soil), by employing uniform design and single factor design. Compared to the control, content of exchangeable K was decreased, but that of soluble K increased in the samples contaminated with heavy metals. Due to heavy metal pollution, potassium adsorption was reduced by 5% to 22%, whereas the desorption percentage of adsorbed K increased by 2% to 32%. The Q/I curves shifted downward, potassium buffering capacity (PBCK) decreased, and equilibrium activity ratio values (ARoK) increased with increasing heavy metal pollution. These influences followed the sequences of Ph>Cu>Zn and combined pollution>single one. Displacement of K from canon exchange sites and decrease in soil CEC due to heavy metals should be responsible for the changes of soil K behaviours. The findings suggest that heavy metal pollution of soil might aggravate the degradation of soil K fertility by decreasing K adsorption and buffering capacity and increasing desorption.

Corrosion of carbon steel,zinc and copper by air pollution in Chongqing

This paper presents the research on the atmospheric corrosion rates of carbon steel, zinc and copper in Chongqing, which was a corrosion subprogram of an international project, Regional Air Pollution in Developing Countries. We performed field exposure tests of carbon steel, zinc and copper at an urban site Guanyinqiao and a rural site Tieshanping inChongqing, then used grey relational analysis, based on the database of the whole corrosion project, to determine the order of the effect of environmental factors on corrosion rates of tested metals, and established dose-response functions for these three metals. The results showed that the two crucial agents of acidic environment, SO2 and H+, were common factors that contributed most to the corrosion of the tested metals. The established dose-response functions for outdoor carbon steel and zinc are proved applicable to use in Chongqing, but the function for copper needs further modifying. We employed these dose- response functions and general environmental data to elaborate the maps of corrosion rate respectively of carbon steel and zinc by geological information system (GIS) technique which help to identify areas of high corrosion damage risk. An acceptable annual average SO2 level of 21 μg/m3 for carbon steel and that of 61 μg/m3 for zinc are also put forward to control the air pollution impact on atmospheric corrosion in Chongqing urban areas.

Removal of Heavy Metals （Copper, Manganese and Zinc） from Industrial Wastewater of Baiji Refinery by Granular Activated Carbon

The aim of the present work is to remove heavy metals （copper, manganese, and zinc） from industrial wastewater of Baiji refinery using GAC （granular activated carbon）. The most important factors affecting adsorption process have been studied, which are granular activated carbon thickness, H, inlet pollutant concentration, Cv, and liquid hourly space velocity, LHSV. All experiments were performed under constant temperature at 25℃ and pH = 7. The experimental apparatus was designed and constructed to enable controlling of the operating conditions. Employing five levels for each of H and LHSV and three levels for Co required 75 runs for each metal. Box-Wilson method was used to reduce the number of experiments to 15 for each metal. The results indicated that copper, manganese, and zinc can be completely removed from wastewater using activated carbon. However, breakthrough time for zinc is low. It is also shown that breakthrough time （TB） and exhaustion time （TE） are inversely proportional with pollutant concentration and LHSV （liquid hour space velocity） while it is directly proportional with the thickness of activated carbon column.