A critical review on lead migration, transformation and emission control in Chinese coal‐fired power plants

Coal is widely utilized as an important energy source, but coal-fired power plant was considered to be an important anthropogenic lead emission source. In the present study, the distribution characteristics of lead in coal and combustion by-products are reviewed. Specifically, lead is mainly transferred to ash particles and the formation and migration mechanisms of particulate lead are summarized. Also, targeted measures are proposed to control the formation of fine particulate lead as well as to increase the removal efficiency during the low-temperature flue gas clean process. In detail, interactions between gaseous lead and some coal-bearing minerals or added adsorbents could obviously suppress the formation of fine particulate lead. On the other hand, some efforts (including promoting capture of fine particles, reducing resistivity of particles and strengthening the gas-liquid contact) could be made to improve the fine particulate lead removal capacity. Notably, the formation mechanism of fine particulate lead is still unclear due to the limitations of research methods. Some differences in the removal principles of fine particles and particulate lead make the lead emission precisely control a great challenge. Finally, the environmental potential risk of lead emission from flue gas and ash residues is addressed and further discussed.     

萃取色层-原子吸收法测定废水中痕量铅和镉

萃取色层-原子吸收法测定废水中痕量铅和镉采用吸附树脂GDX-301,粒度60～80目为支持体,以双硫腙0.2%四氯化碳溶液;甲基异丁基酮(MIBK)混合为萃取剂的萃取色层柱分离富集废水中痕量铅、镉,用0.5N盐酸20 ml分4～5次洗脱,流速为1 ml/min,洗脱液承接于25 ml容量瓶中,用去离子水定容后与标准系列同时在原子吸收分光光度计上分别进行铅、镉含量的测定.方法用于一般工业废水和生活饮用水中微铅、镉的测定.     

天津市环境空气中铅（Pb）的污染

本文统计分析了１９９４￣１９９６年天津市环境空气及交通环境中铅的浓度值，分析了天津市环境空气及交通环境中锅污染的程度、变化趋势、污染来源。由此说明天津市出现“尾气型”污染的迹象。为此，务必加大力度对机动车尾气排放的监测和管理，这对降低污染，改善天津市环境空气质量具有一定的现实意义。     

A co-operative approach to risk management in an active lead/zinc smelter community

Trail, Canada has been the site of a large lead/zinc smelting facility since 1916. In mid 1990, the Trail Community Lead Task Force was established and given responsibility for developing a strategy to reduce children's blood lead levels. With funding from the provincial government, the smelting company and the municipal government, the Task Force has carried out blood lead screening, case management, community education, exposure pathways modelling and remediation trials. The decline in children's blood lead levels appeared to accelerate following the implementation of these programmes. The average blood lead in Trail children aged 6–72 months fell 14% from the autumn of 1991 to autumn of 1992, whereas for the previous 16 years, the average annual decline had been about 4%. In subsequent years, blood lead levels have appeared to plateau. Throughout the 5-year history of the Task Force, its members have demonstrated a strong sense of common purpose and have worked co-operatively to reach consensus on most issues.     

东方香蒲(Typha orientalis Presl)对铅的富集特征及其EDTA效应分析

通过野外调查和水培试验，研究了生长在永州铅锌铜尾矿上的优势植物东方香蒲（Typha orientalis Presl）对铅的富集特征及EDTA对其吸收和运输铅的影响。野外调查表明，东方香蒲对铅有很强的富集作用，其地上部分铅平均质量分数为619mg／kg，地下部分铅平均质量分数为1233mg／kg。营养液培养试验进一步证实了它的强富集能力，其地上和地下部分的铅质量分数都远远超过了超富集定义的参考值（1000mg／kg）。分析结果表明，东方香蒲是一种新的铅富集型植物，EDTA的加入不仅增加了植株对铅的吸收量，而且增大了铅在植株体内的转运系数。同时，铅对植株的毒害症状也得到缓解。     

Enrichment and exposure of particulate lead in a traffic environment in India

Enrichment of lead in respirable suspended particulate matter (RSPM) and exposure of human blood to particulate lead in traffic environment were investigated. Samples of RSPM, non-respirable suspended particulate matter (NRSPM) and total suspended particulate matter (TSPM) were collected in 10 sampling sites located on National Highway No. 6, Durg–Bhilai section of Chhattisgarh State of India. Forty blood samples, out of which 20 of highway traffic personnel with chronic exposure and other 20 of general population who were residing more than 10 km away from the National Highway, were collected. Samples of particulate matter were weighed and analysed for particulate lead. Results have shown a higher concentration of average RSPM and TSPM in all the sampling sites compared to the Indian permissible limits. Geometric mean of lead levels was found in the range of 0.880–1.414 µg/m³ (TSPM) in the study sites. Concentrations of lead in RSPM have shown a higher enrichment (range 2.645–3.171) relative to NRSPM. Blood lead levels in traffic personnel and general population were found in the range of 56.70–101.17 µg/dL and 7.92–31.22 µg/dL, respectively.     

Effects of lead exposure on redox status,DNA and histological structures in Venus verrucosa gills and digestive gland

ABSTRACT

Lead (Pb) is one of the most toxic heavy metals that affect the physiological status of aquatic organisms. The present investigation evaluated the possible toxic effect of lead chloride (PbCl₂) on biomarkers responses, DNA damage and histological alterations in Venus verrucosa gills and digestive gland. Three concentrations of PbCl₂ (D1:1µgL^?1, D2: 10µgL^?1 and D3: 100µgL^?1) were chosen for V. verrucosa exposure during six days. At the end of the trial, it was found that Pb tended to accumulate in both gills and digestive gland in a dose-dependent manner. However, gill tissues exhibited the highest metal burden. Our results showed an increase of malondialdehyde, protein carbonyls and advanced oxidation protein product levels in both organs following PbCl₂exposure. The induction of both non-enzymatic and enzymatic antioxidant systems; as well as the decrease of the acetylcholinesterase activity and degradation of DNA structure was recorded in the gills and digestive gland. The histopathological alterations observed in gills (disruption of lamellas and cilia filaments?…) and digestive gland (lumens occlusion, necrosis and fibrosis) confirmed the aforementioned results. Our data highlighted the short-term toxicity effects of PbCl₂ on V. verrucosa and pointed out a high sensitivity of gills towards this metal.     

Contaminant source apportionment by PIMMS lead isotope analysis and SEM-image analysis

By combining scanning electron microscopy (SEM) image analysis and laser ablation plasma ionisation multi-collector mass spectrometry (LA-PIMMS), high precision lead isotope analyses can be obtained from individual metal-rich particles. Soils from Wolverhampton and Nottingham were sampled on the basis of high Pb concentrations or brownfield location. Pressed powder pellets of each were rastered by LA-PIMMS to obtain a bulk Pb-isotope signature. The results plot along an apparent mixing line between the major sources of lead contamination in the UK, that is UK ore deposits and alkyl-lead from petrol additives (Australian ore). Two particularly lead-rich soils were chosen to investigate the lead distribution and isotope variability between size and density fractions. The fine-grained and low-density fractions contained most of the lead and have Pb-isotope ratios comparable with the bulk soils. By contrast, the small, lead-enriched denser fractions contained only a minor proportion of the total lead but Pb-isotope signatures indicating relative enrichment in one or other of the end-members from the mixing line. Further characterisation of individual Pb-rich grains is in progress.     

铅胁迫下La(NO3)3对油菜抗氧化酶的影响

用盆栽实验研究了 1g·kg- 1和 2g·kg- 1铅胁迫下 ,分别以 0 1 ,0 3和 0 5g·l- 1La(NO3 ) 3 溶液浸种 ,然后测定油菜幼苗中超氧化物歧化酶 (SOD)、过氧化氢酶(CAT)的活性和脂质过氧化产物丙二醛 (MDA)的含量 ,以及油菜幼苗生长的情况 .结果表明 ,稀土元素镧可以提高油菜幼苗地上和地下部分超氧化物歧化酶和过氧化氢酶的活性 ,并降低丙二醛的含量 ,但是对于油菜幼苗生长的影响并不显著 ,显示镧能够在一定时间内抑制超氧阴离子自由基的产生以抵御铅的胁迫 .     

低浓度铅暴露对鲫鱼肝脏抗氧化系统的影响

研究了鲫鱼幼体 (Carassiusauratus)在低浓度铅的长期 ( 4 0d)暴露实验中 ,鲫鱼抗氧化系统所产生的生理生化反应 .结果表明 ,在本实验的剂量范围内 ,铅对鲫鱼肝脏内过氧化氢酶 (CAT)、超氧化物歧化酶 (SOD)的活性 (在暴露浓度达到 0 2mg·l- 1时 )表现为诱导作用 ;而铅对谷胱甘肽硫转移酶 (GST)、谷胱甘肽过氧化物酶 (GSH Px)的活性在低浓度时 ( 0 0 1mg·l- 1)被抑制 ,其中暴露浓度在 0 2mg·l- 1时GSH Px被进一步抑制 .在实验范围内 ,GSH含量无明显变化 .另外 ,对于低浓度铅的长期暴露 ,鲫鱼肝脏中的GST和GSH Px较CAT和SOD敏感 ,可考虑作为水生生态系统中铅低浓度长期暴露的一种生物检测指标 .