英语翻译Samples were then dried in an ovenat 110?C,sifted through a 2-mm sieve to remove extraneousmaterials,and retained for further analysis.Two grams of thesample were accurately weighed and digested for total heavymetal analysis using the wet

英语翻译Samples were then dried in an ovenat 110?C,sifted through a 2-mm sieve to remove extraneousmaterials,and retained for further analysis.Two grams of thesample were accurately weighed and digested for total heavymetal analysis using the wet
英语翻译
Samples were then dried in an oven
at 110?
C,sifted through a 2-mm sieve to remove extraneous
materials,and retained for further analysis.Two grams of the
sample were accurately weighed and digested for total heavy
metal analysis using the wet digestion procedure.The sample
was transferred to a polyethylene test tube and digested with
15 mL of a 1:1 mixture of nitric acid (HNO3):perchloric acid
(HClO4).The mixture was heated at 80?
C for 2–3 hours us-
ing a heating block.The contents were ltrated and transferred
through a simple ltration apparatus into a 25-mL polyethy-
lene volumetric ask.The lter paper was washed several times
with 1% HNO3,and the volume was completed to 25 mL with
1% HNO3.The solutions were stored in sealed plastic bottles
prior to analysis.The heavy metals (Pb,Cu,Zn,Ni,Fe,Al,Cr,
Co,Cd,Mo,and Mn) were determined in dust samples using
aPerkin Elmer Flame Atomic Absorption Spectrophotometer
model Analyst 300 (Perkin Elmer,Wellesley,MA,USA).Stan-
dard stock solutions of each metal (1,000 μg/mL) in 1% HNO3
were used to prepareworking standards.Calibration curveswere
built up for each metal where r > 0.995.Reagents blanks (two
per eight samples) were prepared by carrying out the whole ex-
traction procedure.All materials used for analysis (e.g.,bottles,
glassware) were washed thoroughly,rinsed with 1% HNO3,and
nally rinsed with distilled water.
The mineral constituents of the dry deposition samples were
determined using x-ray diffraction system(Philips-X` pertMpD,
PANalytical B.V.,Almelo,The Netherlands).The ne powder
samples were randomly mounted on special slides and then
scanned between
and 65?
2 θ,using Ni-?ltered Co Kα radia-
tion,40 kv/40mA,divergent and scattering slits of 0.02?
mm,a
receiving slit of 0.15 mm,with stepping of 0.01?
and scanning
speed of /min.
Results and Discussion
Heavymetals are naturally occurring constituents in the environ-
ment in low concentrations.Anthropogenic activities can cause
elevated levels of metal concentration in various parts of the
ecosystem.Heavy metals in river sediments,for instance,are
considered more sensitive than dissolved contamination as indi-
cators of contamination (Gaiero et al.,1997).The anthropogenic
sources of heavy metals in an urban environment could result
from multiple sources.Cu can result from electronic and metal-
lurgical industries,whereas Ni,Pb,Cd,and Zn can result from
fossil fuel combustion andmanufacturing industries such as that
for batteries,paints,printing and graphics,medicine,and met-
allurgy (Alloway and Ayres,1997).

英语翻译Samples were then dried in an ovenat 110?C,sifted through a 2-mm sieve to remove extraneousmaterials,and retained for further analysis.Two grams of thesample were accurately weighed and digested for total heavymetal analysis using the wet
样本,然后干燥炉
在 110 吗?
通过删除多余 2 毫米筛子仔细的 C
材料,并保留作进一步分析. 两克,
示例是准确地衡量和消化的总重
金属分析使用湿的消化过程. 该示例
被转移到一个聚乙烯试管,与消化
15 毫升的氮酸 (HNO3) 1： 1 混合： 高氯酸
(HClO4). 混合被加热八十元吗?
C 2–3 几个小时我们-
ing 加热块. 该内容被呢? ltrated,转
通过一个简单的吗? 到 25 毫升 polyethy-ltration 仪器
丙烯容量吗? 问. 在吗? lter 份文件洗了几次
1 %HNO3 和卷已完成与 25 毫升,
1 %hno3. 该解决方案存储在密封的塑料瓶
之前,分析. 重金属 (铅、 铜、 锌、 镍、 铁、 铝、 铬,
钴、 镉,钼和锰） 决定中使用的灰尘示例
埃尔默火焰原子吸收分光光度计 aPerkin
模型分析师 300 韦尔斯利,MA,美国珀金埃尔默）. 斯坦-
dard 股票解的 1 %HNO3 的每个金属 (1,000 μg/毫升）
用于 prepareworking 的标准. 校准 curveswere
生成了对每个金属其中 r > 0.995. 试剂空白 (两个
每八个样本）,在拟备进行整个前 —
牵引的过程. 所有的材料,用于分析 (例如,瓶,
玻璃制品） 被清洗彻底,1 %HNO3,清洗和
吗? 蒸馏水冲洗用的 nally.
干沉降所采集的所有样本的矿物成分是
决定使用 x 射线衍射 system(Philips-X' pertMpD,
PANalytical 公司,Almelo,荷兰). 在吗? ne 粉
样本被随机装上特别的幻灯片,然后
扫描 2 之间吗?
至六十五岁呢?
2 使用镍的 θ 吗? ltered 公司 Kα radia-
研究 40 kv/40mA,不同与散射缝的 0.02 吗?
mm,一
接收 0.15 毫米,用走的 0.01 的缝吗?
和扫描
3 的速度吗? / min.
结果与探讨
Heavymetals 天然成分的环境-
在低浓度的方法. 人为活动可能会导致
更高水平的各个部分的金属含量,
生态系统. 河流沉积物,重金属,例如是
考虑更多敏感简报 — 溶解污染比
污染 (Gaiero et al,1997年） 的 cators. 人为
可能会导致在城市环境中的重金属污染的来源
来自多个源. 铜可因电子和金属-
法的工业而镍、 铅、 镉和锌可因
化石燃料燃烧 andmanufacturing 行业,例如,
电池、 涂料、 印刷和图形、 医学,并举行 —
allurgy （Alloway 和脚跟,1997年）.