The effects of the 3 main wastewater discharges on the benthic fauna of the Manawatu River were studied between March 1979 and January 1980. At least 4 replicate Surber samples were taken from each of 6 sites, on 5 occasions during this period. Deleatidium sp. (Ephemeroptera), Hydora sp. (Coleoptera), and the Chironomidae were the most useful indicator organisms, according to a ranking system based on the occurrence of significant differences (P<0.05) between populations at different sites. These taxa exhibited significant differences between sites in about 70% of all inter‐site comparisons, using Mann‐Whitney U‐tests. The Coefficient of Similarity was successful at summarising the comparisons between the clean‐water and down‐stream sites, ranging between 95% similarity to the clean‐water site for a recovery site in winter, and less than 10% similarity to the clean water site for the lower reaches in summer. It is suggested that relative indices may be more appropriate than absolute indices for measuring water pollution. Water quality, indicated by species diversity, was generally good (allowing for the effects of agricultural runoff), although midsummer organic loading induced marked changes in benthic species composition, including the disappearance of Deleatidium sp. from several sites. 相似文献
The beginning of polymetallic sulphide ore exploitation at Almagrera, Iberian Pyrite Belt, SW Spain, has been dated back to pre-Roman times; mining activity lasted until 2001 when it was definitely halted. The Almagrera sulphide tailings dam was built at the Sotiel–Coronada mine, where Cu, Zn and Pb concentrates were obtained by flotation processes, and sulphide (mainly pyrite) wastes formed. The dam was built as a water-reservoir, on a tectonic fault; its hazard is currently documented by the released wastes after a strong storm in the region, then, its stability is not monitored by the owner. 相似文献
In China, coal mining wastes have traditionally been dumped in cone-shaped heaps that have the potential to pollute air, soil
and water environments and landscapes through dust generation, leachate production, self-ignition and as a consequence of
an absence of vegetation cover. Since 1980s, the disposal technique for coal mining wastes has been changing and in many instances
the wastes are now transported directly to subsided land as a fill to enable the reuse of that land. Thus, today, both coal
mining waste dumps from the past and filled subsided lands are in existence. However, the comparative impacts of these different
disposal techniques on the environment and farmland productivity have not been studied in detail. Using Dongtan (DT), Nantun
(NT) and Xinglongzhuang (XLZ) coal mines as examples, the components of coal mining wastes and their potential pollution contribution
to soil, surface water and ground water are tested in-situ. The results show that contaminants are released after self-ignition
and weathering of coal mining wastes, but they are not above the allowable environmental standards. However, despite these
findings, more and closer attention needs to be paid to the mobility, transportation and accumulation of these contaminants
in the environment over time. 相似文献
We studied the mobility of silver, heavy metals and europium in waste from the Las Herrerías mine in Almería (SE Spain). The
most abundant primary mineral phases in the mine wastes are hematite, hydrohematite, barite, quartz, muscovite, anorthite,
calcite and phillipsite. The minor phase consisted of primary minerals including ankerite, cinnabar, digenite, magnesite,
stannite, siderite and jamesonite, and secondary minerals such as glauberite, szomolnokite, thenardite and uklonscovite. The
soils show high concentrations of Ag (mean 21.6 mg kg–1), Ba (mean 2.5%), Fe (mean 114,000 mg kg–1), Sb (mean 342.5 mg kg–1), Pb (mean 1,229.8 mg kg–1), Zn (mean 493 mg kg–1), Mn (mean 4,321.1 mg kg–1), Cd (mean 1.2 mg kg–1) and Eu (mean 4.0 mg kg–1). The column experiments showed mobilization of Ag, Al, Ba, Cu, Cd, Eu, Fe, Mn, Ni, Sb, Pb and Zn, and the inverse modelling
showed that the dissolution of hematite, hausmannite, pyrolusite and anglesite can largely account for the mobilization of
Fe, Mn and Pb in the leaching experiment. The mobility of silver may be caused by the presence of kongsbergite and chlorargyrite
in the waste, while the mobility of Eu seems to be determined by Eu(OH)3, which controls the solubility of Eu in the pH–Eh conditions of the experiments. The mineralogy, pH, Eh and geochemical composition
of the mine wastes may explain the possible mobilization of heavy metals and metalloids. However, the absence of contaminants
in the groundwater may be caused by the carbonate-rich environment of “host-rocks” that limits their mobility. 相似文献
Drilling of 15 boreholes at a disused liquid waste disposal site near Perth, Western Australia, has indicated that a contamination
plume extends about 1000 m in a southerly direction from the site in the direction of groundwater flow. The plume is up to
600 m wide and 5–40 m thick. Chemical and microbiological analyses have indicated that contaminated groundwater contains high
concentrations of ammonia, iron, and bacteria at levels that commonly exceed national drinking water guidelines. It is likely
that a proposed water supply production well in the path of the contamination plume will have to be abandoned, and additional
wells may have to be abandoned if the plume continues to extend in the direction of groundwater flow. There is currently insufficient
information to indicate whether the plume is continuing to expand, but studies on similar plumes in the Perth metropolitan
area have indicated that contaminated groundwater can move at rates up to 100 m yr–1. Several other liquid waste disposal sites are now located in residential areas of Perth where wells are used for garden
irrigation. Further work is required to ensure that there is no potential impact of groundwater contamination on public health
in these areas.
Received: 31 July 1995 · Accepted: 18 September 1995 相似文献
The most common and difficult of all hazardous waste sites are those that historically produced artificial (manufactured) gas; for gas-making was international in scope and at the very core of the industrial revolution. With former manufactured gas plants (FMGPs), virtually no geologic region in the industrialized or urbanized world or its trade centers and ports escaped the gas industry. These plants applied pyrolysis of organic matter (roasting to drive off volatiles in the form of useful gases) to illuminate the world and to fuel all manner of progress.
Gas was and is the universal fuel. Its prominence stemmed from the omnipresence of organic matter and the universal process for the extraction of its volatile contents to manufacture useful gas. Furthermore, for most of the century and a half-long history of manufactured gas, natural gas was unavailable to slow or daunt the production of man-made gas and the universal creation of its toxic tar residues and other harmful waste residuals.
Today we face the presence of toxic organic gas manufacturing residuals as a unique threat to both the health and welfare of contemporary society, as well as being a long-term threat to the environment that is dominantly geologic in character. Most of these tar residuals are highly resistant to natural degradation or attenuation in the environment and their lives, therefore, they are measured in geologic time. Given its environmental persistence, potential problems associated with tar may exist centuries to thousands of years.
Engineering geologists and geological engineers are, by training and experience, particularly well equipped to plan, manage and conduct site and waste characterization efforts for FMGPs and related coal-tar sites. 相似文献
Scoping calculations were performed in order to assess the influence of radiogenic heat on the performance of the rock mass around a nuclear fuel waste repository. The full coupling between the thermal, mechanical and hydrological processes involved was considered by using the finite element code, FRACON, developed through an extension of Biot's classical theory of soil consolidation. By considering the full T---H---M coupling, several important safety features, which would otherwise be omitted in uncoupled analyses, were detected in the present study. In particular, it was shown that the heat-induced pore pressure increase around the repository has the potential to significantly increase the rate of groundwater flow, and affect the structural integrity of the rock mass. 相似文献
The selection of the disposal site is probably the most important step in the development of solid waste management. In site selection, geology plays a determining role. This study evaluates the characteristics of the environment on the basis of the geological, hydrogeological and geo-engineering properties of the solid waste site of the Sivas city, Turkey. The area is underlain by the Oligocene-Miocene rocks which have limited aquifer properties. Thin Quaternary alluvium and soil cover overlie the Oligo-Miocene rocks, which are represented as well graded sand and inorganic silt of low plasticity. The Quaternary alluvium and soil cover are classified as inorganic clays having a low plasticity and the permeability varies from 1.2×10−6 to 3.11×10−6 m/s. These values are much higher than 1×10−8 m/s, which is accepted for waste disposal standards. Seepage waters have a potential to pollute the ground water and the Kızılırmak River, which is 500 m to the southwest of the waste disposal area and because the disposal site is close to the river, the potential for flash flooding poses a high pollution risk. The waste disposal area must be covered by clay layers or an impervious artificial membrane. In addition, seepage must be controlled and removed from the site. 相似文献