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The purpose of this work was to study the distribution of airborne particles in the surroundings of an iron and steel factory in southern Finland. Several sources of particulate emissions are lying side by side, causing heavy dust loading to the environment. This complicated multi-pollutant situation was studied mainly by SEM/EDX methodology.Particles accumulated on Scots pine bark were identified andquantitatively measured according to their element content,size and shape. As a result, distribution maps of particulateelements were drawn and the amount of different particle typesalong the study lines was plotted. Particulate emissions fromthe industrial or energy production processes were not themain dust source. Most emissions were produced from theclinker crusher. Numerous stockpiles of the industrial wastesand raw materials also gave rise to particulate emissions as aresult of wind erosion. It was concluded that SEM/EDXmethodology is a useful tool for studying the distribution ofparticulate pollutants.  相似文献   
3.
A study has been made on elements organic constituents, TSP, SO2,NO2 of atmospheric pollutants in Beijing. 17 elements, and some PAHs, e. g. B(a)P, B(b, j, k)P, and B(g, h, i)P, in airborne particles by X-ray fluorescence spectroscopy and HPLC, GC/MS, have been determined respectively. It has been shown that the elements Pb, Zn, S and Cu were more enriched in fine particles and different valence states of sulfur at various sites. It was found that the concentrations of S6+ and S2-were more than 85% and less than 15% of the total sulfur respectively. Concentrations of major PAHs and sulfur-containing compounds increased in winter and in urban area. High values for Pb and Zn in city, Fe and Mn at industrial area and Cu, Al rural sites were obtained respectively. This implies the functions of different elemental sources of various sites. Thus, elements can be from distingushed anthropogenic and natural sources.The main contribution of SO2 was found of to have same seasonal variation as the anthropogenic el  相似文献   
4.
Wastewater treatment using waste materials (refuse concrete, waste paper and charcoal) and natural indigenous rocks (andesite, limestone, granite and nitrolite) in the form of multilayer media was investigated. The removal of suspended solids (SS), phosphate ion, nitrate ion, ammonium ion, toxic metals and chemical oxygen demand (COD) were evaluated for the multilayer wastewater treatment system. Effective removal of heavy metals such as cadmium, chromium, mercury and lead was demonstrated. SS and phosphate ion were removed with relatively high efficiency and the COD after treatment was lessened using certain combinations of media. The present wastewater treatment system is simple, convenient and low cost. Therefore, this method can be applied in small scale plants for wastewater treatment in local and nonexclusive areas.  相似文献   
5.
Some polyclads associate with other marine invertebrates such as gastropods, but how these associations evolve is not well understood. This study examined the relationships between a polyclad, Stylochoplana pusilla, and six species of snails in 10 eulittoral sites in Mutsu Bay, northern Japan, in 2010 and 2011. Of the six potential host snail species, Monodonta labio was present at all sites and the prevalence of S. pusilla in the snails’ mantle cavities overall was 82.6 %. Four other snail species occurred at five or six sites in comparable densities, but of these, only Chlorostoma turbinatum and Omphalius rusticus had S. pusilla in their mantle cavities (prevalence of 42.0 and 15.4 %). A congener of M. labio, Monodonta neritoides, occurred at only one site and had no S. pusilla. The mantle, which provides habitat space for S. pusilla, was proportionally the longest in M. labio. In laboratory experiments, the flatworms preferentially entered M. labio over other snail species with the same mantle length. Observed vertical distributions of snails in the littoral zone indicate that M. labio is present in the eulittoral at both high and low tides, while C. turbinatum and O. rusticus are usually found in the sublittoral. In an evolutionary sense, the relationship between S. pusilla and its host may have developed as a mechanism for the flatworm to avoid predation by living in the eulittoral and to avoid desiccation by establishing commensal relationships with certain snails.  相似文献   
6.
The economy of Northeast Thailand is mainly based on agriculture. The transformation of forestlands to agricultural areas and the encroachment of riverbanks within the Phong watershed have caused severe soil erosion. Strong storms in rainy season exacerbate the problem of soil erosion. Difficulty in getting water drives people in the upstream region to live on riverbanks. Soil erosion affects water utility by increasing the turbidity in the Phong River and also by decreasing the water storage capacity of small reservoirs for the upstream residents, as well as that of the Ubolratana Dam. The rate of siltation in the Ubolratana Dam was estimated to be 1.5 million tons/year during 1965-1990. The main source of water supply is surface water in the Phong watershed, and fluctuating turbidity makes water treatment difficult. The maximum turbidity in the upstream Phong River exceeds 5000 NTU, whereas it is reduced to be about 300 NTU at the intake point of Khon Kaen Municipal Water Treatment Plant because the Ubolratana Dam works as a huge clarifier. Khon Kaen Municipal Waterworks has a daily water supply of 72,960 m3/day. The average amounts of alum used in the wet (May-October) and dry (November-April) periods are 42.33 g/m3 and 28.46 g/m3, respectively. The average costs of the amounts of alum used are 0.213 and 0.143 Bahts/m3 during the wet and dry periods, respectively. Fluctuation of turbidity in raw water makes it difficult to adjust alum dose, resulting in treated water quality unstable, and handling of sludge disposal difficult.  相似文献   
7.
为提高乳品工业废水生物处理的去污脱氮能力,以新型螺旋状纤维填料作为载体,采用多级氧化槽内不同种类微生物形成的食物链系统(food chain reactor),详细考察了不同水力停留时间COD、TN、NH4-N、TP等的去除率及其去除机理,并对污泥减量化效果进行了初步探讨.结果表明,当进水COD为842~1 843  mg/L、TN为36.3~92.2  mg/L、NH4-N为30.1~52.1  mg/L,HRT=6 h时,系统COD的平均去除率达到93.3%;TN和NH+4-N的去除效果显著,其平均去除率分别达到73.3%和80.7%,出水COD、TN、NH+4-N平均值分别为79.4 mg/L、9.6  mg/L、6.1 mg/L,均低于《污水综合排放标准》(GB 8978-2002)的一级标准.该系统不仅具有较高的去污脱氮效果,而且产生的剩余污泥量极少,其污泥产率的平均值为7.7%.该系统运行费用低,操作管理方便,长期运行稳定,可应用于城市污水、中高浓度有机废水(如餐厅污水、食品工业废水)等的处理.  相似文献   
8.
Total suspended particulate mater (TSP) concentrations were monitored for one year from July 2000 and for one year from April 2003 in Jakarta City. Thirteen elemental TSP components, aluminum (Al), sodium (Na), iron (Fe), lead (Pb), potassium (K), zinc (Zn), titanium (Ti), manganese (Mn), bromine (Br), copper (Cu), chromium (Cr), nickel (Ni), and vanadium (V) were analyzed by a sequential X-ray fluorescence spectrometer. Al, Na, Fe, K, and Pb were major components at most of the sampling locations in 2000. However, only Pb in 2003 dramatically decreased to one tenth. The phase-out of leaded gasoline began on July 1, 2001 in Jakarta City and lead content in gasoline decreased to one tenth, too. The decrease in Pb concentration was a result of the phase-out of leaded gasoline, as lead emissions mainly are exhaust gas from vehicles.  相似文献   
9.
This study reports sorption isotherms of the endocrine disruptors nonylphenol (NP) and octylphenol (OP) in three sediment samples from the Ebro River basin (NE Spain), with organic carbon fractions (fOC) ranging from 0.0035 to 0.082 gOC g−1. All isotherms were fitted to the Freundlich model with slightly nonlinear exponents ranging from 0.80 to 0.94. The solubility of the compounds as well as the organic carbon (OC) content had the strongest influences on the sorption behavior of these compounds. Comparison of the laboratory-spiked samples with the native contamination of NP of 45 water and concurrent sediment samples resulted in reasonable matches between both data sets, even though the lowest concentrations in the field were not completely reached in laboratory tests. This good agreement indicates that sorption laboratory data can be extrapolated to environmental levels and therefore the distribution of nonylphenol between sediments and water can be predicted with a precision of one order of magnitude. Furthermore, laboratory experiments with simultaneous loading of NP and OP revealed negligible competition for sorption sites at low concentrations.  相似文献   
10.
Attention has been focused on the treatment of lignite-fired flue gas in order to use lignite in an environmentally friendly way – (i) low-CO2 emission, (ii) production of a valuable by-product, (iii) no discharge of wastewater, (iv) direct removal of SO3 (strong toxicity), and (v) treatment of high SO2 concentration. Based on these criteria, electron beam irradiation with ammonia injection was tested on a semi-pilot scale: 800 Nm3 h?1 flow rate, 5500 ppm SO2, 70 ppm NOx, 22% flue gas moisture, and 75–80 °C at the reactor outlet.As an energy-saving measure, a low dose (5 kGy) of irradiation was applied: the problem lay in the by-product quality. It is considered that (NH4)2SO3 and NH4HSO3 produced by thermal reactions are oxidized to form (NH4)2SO4 (fertilizer) by an electron beam. However, not all reactions were complete because the by-product contained small amounts of H2SO4 and NH2SO3NH4 (herbicide), so a vegetable pot test was performed to study the by-product quality: no adverse effect was observed. It is inferred from the pot test that slightly acidic soil may protect vegetables from disease and a small amount of NH2SO3NH4 probably affects woody species and not herbaceous species.It is concluded that the electron beam system is noted as a multi-component pollution control process (removal of NOx, SO3, SO2 and dioxins) and this system will contribute to environmentally friendly use of lignite as well as agricultural productivity via fertilizer supply.  相似文献   
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