印染污泥焚烧烟气污染控制案例分析

以广东省某两家印染厂的印染污泥焚烧项目为主要研究对象,从污泥处理技术路线、焚烧设备及烟气处理流程等各方面入手,对各厂印染污泥与煤混烧烟气中颗粒物、NOx、SO2、酸性气体(HF、HCl)和重金属等污染物的进行采样分析,并对各厂现有烟气污染物控制设施的运行效果进行调研,结果表明,布袋除尘的效果较为理想,除尘效率可达99%以上;使用印染废水作为吸收液的湿法脱硫技术对SO2及酸性气体的去除效果不理想;SNCR对NOx具有一定的去除效果,是一种较为经济、高效的脱硝技术;焚烧后,大部分重金属最终以飞灰的形式被除尘器去除,但仍有部分重金属如Hg在出口烟气中的浓度仍然很高,需要采取必要的措施控制烟气中的重金属. 此外,基于印染污泥焚烧实例分析,提出适于印染污泥与煤混烧烟气处理工艺流程.     

Mechanistic aspects of the thermal formation of halogenated organic compounds including polychlorinated dibenzo‐p‐dioxins. Part V†: Hypotheses and summary

The hypotheses on the de novo syntheses of polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo‐p‐dioxins (PCDDs), based on known literature, are presented. Polychlorinated benzenes and polychlorinated phenols are probably key intermediates.

In the present article, hypotheses that may account for the presence of polychlorinated dibenzofurans (PCDFs) and dibenzo‐p‐dioxins (PCDDs) in the effluents from municipal and industrial incinerators are put forward. These hypotheses are based on the previously surveyed literature (Ref. 203–206) and experimental results on laboratory scale and thermodynamic calculations are considered. The interconnections of various reaction steps are speculative and no technological information was added to account for conditions in real incinerators. Conclusion of the discussions on the related subject matter, presented in the Parts I‐IV (Ref. 203–206), are also described in this paper.     

Speciation of heavy metals in suspended particulates in urban air†

An anayltical procedure based on a sequential extraction scheme is applied to samples of suspended particulates from an urban area of Barcelona. This area presents high levels of air pollution owing to automotive emissions and industrial activity.

The procedure allows the partitioning of particulate trace metals into four fractions: soluble and exchangeable, bound to carbonates and iron‐manganese oxides, bound to organic matter and residual. In this work, the chemical associations of Fe, Pb, Cu, Mn, Cr and Cd have been investigated.

In the analysed samples, only the cadmium is predominantly in the first fraction whereas the other metals are largely associated to carbonates and Fe‐Mn oxides.     

Heavy metals in coastal sediments in Guipuzcoa (Spain)∗

Surficial sediment samples were wet digested (HNO₃‐HCI‐HF) and analysed by atomic absorption spectroscopy. The background values in the area, and the Pollution Index Load in the sampling points were calculated. Metal inputs of continental origin are specially important in Deva, Oria and Urola river mouths.     

Biotransformation rates of xenobiotic compounds in relation to enzymes activities: A critical review

Many biotransformation reactions and many activities of enzymes involved in the biotransformation of xenobiotics in fish have been described. Therefore, the prediction of biotransformation of (other) xenobiotics through literature data seems to be possible. However, very few data allow correlation of in vitro enzyme activities with in vivo biotransformation rates. This is mainly due to a lack of quantitative data. Suggestions are made for future research, which may help to relate enzyme activities and biotransformation in fish.     

Large plasmids governing multiple resistances to heavy metals: A genetic approach∗

Gram negative bacteria classified as Alcaligenes eutrophus and carrying large resistance plasmids (generally two) were found in various industrial sites highly contaminated by heavy metals (Zn⁺⁺, Cu⁺⁺, Co⁺⁺,...). These strains were detected by DNA hybridization with a probe made with a 9kb fragment (ccz⁺ fragment) encoding for resistances to Cd⁺⁺, Co⁺⁺ and Zn⁺⁺, and cloned from plasmid pMOL30. This plasmid was isolated from the representative strain A. eutrophus CH34 which harbours the plasmids pMOL30 (240 kb) and pMOL28 (165 kb). Phenotypes related to pMOL28 and pMOL30 include the tolerance to Cd⁺⁺, Co⁺⁺, Cr0₄ ⁼, Cu⁺⁺, Hg⁺⁺, Ni⁺⁺, Pb⁺⁺ and Zn⁺⁺. The described genetic properties of these plasmids refer to some cloned or mapped functions and to some plasmid rearrangements. Plasmid pMOL85 (250 kb) which is related to pMOL30 was also described. Its host (A. eutrophus DS185) was isolated from a zinc desert. pMOL85 can efficiently self transfer in plasmidfree derivatives.     

Levels of selected heavy metals in commercial fish from five freshwater lakes,Pakistan

The levels of As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn and Hg are estimated by atomic absorption in the muscle of six commercial species of fish belonging to five freshwater lakes of Pakistan. The species included Mastacembelus armatus, Tor putitura, Mystus seenghala, Wallago attu, Catla catla and Labeo rohita. The fish were procured in comparable weight ranges so that a viable comparison of trace metal content could be effected. As, Fe, Pb, Zn and Hg showed elevated levels of 0.006–6.967, 0.933–6.133, 0.060–4.108, 0.978–5.363 and 0.030–3.211 μg/g, wet weight. The relevant statistical parameters, such as standard deviation, standard error, skewness and its t‐value are also reported for establishing the randomness of the distribution in relation to the corresponding data of freshwater lakes of the world and examined in view of species‐specificity and origin.     

Characterization of airborne particulate matter in Thessaloniki,Greece

A receptor modeling approach has been applied to identify and apportion sources of airborne particulate matter in Thessaloniki, Greece. The absolute principal component analysis source apportionment technique used, provided quantitative information regarding both source particle characteristics and impacts. The analysis identified four major sources of heavy metals within total suspended particles (TSP) in the centre of the city: oil burning, pyrometallurgical non‐ferrous metal processes, motor vehicles and soil resuspension. Their contributions to TSP estimated by regression on absolute principal component scores (APCS) were 12%, 8%, 5% and 4%, respectively. A similar analysis conducted for a sampling site close to the industrial area identified five major sources: oil burning, industrial Cr source, soil resuspension, pyrometallurgical non‐ferrous metal processes and motor vehicles with contributions 20%, 15%, 9%, 8% and 4%, respectively.     

Effect of agrochemicals on earthworms

This review describes the toxic effects of agrochemicals on earthworms. Carbamates are described as extremely toxic to earthworms in comparison to organophosphorus insecticides. Some pesticides have drastic effect on the nervous system of the earthworm. Earthworm can accumulate heavy metals from the soil in higher levels than any other animal. Mercury is twenty times more toxic than chromium.     

上海河流沉积物重金属的污染特征与潜在生态风险

为了解上海市主要河流沉积物中重金属的污染特征,采用电感耦合等离子体发射光谱法(ICP-AES)分析了上海市60个河流表层沉积物中Cu、Pb、Ni、Ag、As、Cd、Zn、Sn、Sb和Hg10种重金属的含量,并对其来源及生态风险进行了评价.沉积物中10种重金属的浓度和介于113.9 ~ 494.0mg/kg之间,平均值为266.1mg/kg.苏州河、黄浦江中下游和黄浦江上游部分采样点重金属污染比较严重.10种重金属的含量由高到低依次为: Zn > Cu> Ni > Pb > As > Sn > Sb> Cd > Hg > Ag.来源分析表明,上海河流沉积物中大多数重金属具有相似的来源,主要来源于工业废水和交通污染、农药和化肥污染.地积累指数(Igeo)评价表明各种重金属的污染程度顺序为: Cd > Hg > Ag > Sb > Cu > Zn > Sn = As > Ni > Pb, Hg和Cd在多数采样点分别为中度污染和偏重污染.潜在生态风险系数(Eri)评价表明各重金属的潜在生态风险顺序为: Cd > Hg > As > Cu > Ni > Pb > Zn, Cd和Hg对潜在生态风险指数(RI)的贡献最大,分别达到65.7%和30.6%. 7种重金属的潜在生态风险指数(RI)介于563.0~1431之间,有极强生态风险.