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91.
本文简要介绍了《１９７２伦敦公约》在中国的实施情况、影响因素以及我国海洋倾废管理的法规、政策、技术标准和管理程序。作者认为，我国海洋倾废管理的目标与公约的目标是一致的，但管理范围比公约更为广泛，并具有更大的强制性。文章还指出，我国的海洋倾放心管理已发展一套较为完整的申请、审批和核准程序，执行效果良好。 相似文献
92.
含高浓度有机物及重金属的废水处理方法研究 总被引：2，自引：0，他引：2
采用铁屑综合处理含高浓度有机物及重金属的废水。经处理后的废水，重金属和ＣＯＤ均达到国家排放标准，研究了铁屑用量，作用时间等的最佳值，并对作用机理作了解释。 相似文献
93.
Two experimental waste-rock piles (test piles), each 15 m in height × 60 m × 50 m, were constructed at the Diavik diamond mine in Northern Canada to study the behavior of low-sulfide content waste rock, with a similarly low acid-neutralization potential, in a continuous permafrost region. One test pile with an average of 0.035 wt.% S (<50 mm fraction; referred to as Type I) and a second test pile with an average of 0.053 wt.% S (<50 mm fraction; referred to as Type III) were constructed in 2006. The average carbon content in the <50 mm fraction of waste rock in the Type I test pile was 0.031 wt.% as C and in the Type III test pile was 0.030 wt.% as C. The NP:AP ratio, based on the arithmetic mean of particle-size weighted NP and AP values, for the Type I test pile was 12.2, suggesting this test pile was non-acid generating and for the Type III test pile was 2.2, suggesting an uncertain acid-generating potential. The Type I test pile maintained near-neutral pH for the 4-year duration of the study. Sulfate and dissolved metal concentrations were low, with the exception of Ni, Zn, Cd, and Co in the fourth year following construction. The pore water in the Type III test pile contained higher concentrations of SO42− and dissolved metals, with a decrease in pH to <4.7 and an annual depletion of alkalinity. Maximum concentrations of dissolved metals (20 mg L−1 Ni, 2.3 mg L−1 Cu, 3.7 mg L−1 Zn, 35 μg L−1 Cd, and 3.8 mg L−1 Co) corresponded to decreases in flow rate, which were observed at the end of each field season when the contribution of the total outflow from the central portion of the test pile was greatest. Bacteria were present each year in spite of annual freeze/thaw cycles. The microbial community within the Type I test pile included a population of neutrophilic S-oxidizing bacteria. Each year, changes in the water quality of the Type III test-pile effluent were accompanied by changes in the microbial populations. Populations of acidophilic S-oxidizing bacteria and Fe-oxidizing bacteria became more abundant as the pH decreased and internal test pile temperatures increased. Irrespective of the cold-climate conditions and low S content of the waste rock, the geochemical and microbiological results of this study are consistent with other acid mine drainage studies; indicating that a series of mineral dissolution–precipitation reactions controls pH and metal mobility, and transport is controlled by matrix-dominated flow and internal temperatures. 相似文献
94.
A numerical model of coupled saturated/unsaturated water flow, heat transfer and multi-component reactive solute transport
is presented to evaluate the long-term geochemical evolution in bentonite, concrete and clay formation for a potential geological
radioactive waste repository. Changes in formation porosity caused by mineral dissolution/precipitation reactions are taken
into account. Simulations were carried out with a general-purpose multicomponent reactive transport code, CORE2D V4. Numerical results show that pH in the bentonite porewater can vary from neutral to up to 13 over a time scale of 1 Ma
although dissolution of silica minerals and precipitation of secondary calcium silicate hydrate (CSH) minerals in bentonite
buffer the effect of the hyperalkaline plume. Mineral precipitation reduces the volume of pore space in bentonite close to
the bentonite–concrete interface due to the precipitation of CSH minerals. Model results indicate that bentonite porosity
decreases less than 25%. The hyperalkaline plume from the concrete only extends to a distance of 0.7 m in the clay formation
over the time range of 1 Ma. 相似文献
95.
Effect of soil disturbance on recharging fluxes: case study on the Snake River Plain,Idaho National Laboratory,USA 总被引：1，自引：1，他引：0
Soil structural disturbance influences the downward flow of water that percolates deep enough to become aquifer recharge. Data from identical experiments in an undisturbed silt-loam soil and in an adjacent simulated waste trench composed of the same soil material, but disturbed, included (1) laboratory- and field-measured unsaturated hydraulic properties and (2) field-measured transient water content profiles through 24 h of ponded infiltration and 75 d of redistribution. In undisturbed soil, wetting fronts were highly diffuse above 2 m depth, and did not go much deeper than 2 m. Darcian analysis suggests an average recharge rate less than 2 mm/year. In disturbed soil, wetting fronts were sharp and initial infiltration slower; water moved slowly below 2 m without obvious impediment. Richards’ equation simulations with realistic conditions predicted sharp wetting fronts, as observed for disturbed soil. Such simulations were adequate for undisturbed soil only if started from a post-initial moisture distribution that included about 3 h of infiltration. These late-started simulations remained good, however, through the 76 d of data. Overall results suggest the net effect of soil disturbance, although it reduces preferential flow, may be to increase recharge by disrupting layer contrasts. 相似文献
96.
在柴达木的矿产资源开发中产生的"废料"不废,如果将这些废料与其它矿产资源相互衔接,就可配置形成一系列产业链。依据循环经济的理论,对资源开发中"废料"资源化再利用进行了循环经济分析。并提出了各种资源开发的"废料"相互衔接和再利用的循环模式。 相似文献
97.
Speciation and solubility relationships of Al, Cu and Fe in solutions associated with sulfuric acid leached mine waste rock 总被引：3，自引：0，他引：3
Solutions from oxidized waste rock originating from an acid-leached waste dump were studied. The dissolution data suggest
that after the majority of the soluble solid phases are removed, remaining solid phases continued to buffer the solutions
in the acidic pH range. Incorporating the solution data into MINTEQA2 identified controls on the solubility of Al, Cu and
Fe at pH values from about 2.5 to slightly over 5. Sulfate appears to play a significant role in the formation of solubility
controlling solid phases for Al and Cu. This is not the case for Fe, and is suggested that Fe and Cu solubility may be controlled
by cupric ferrite at low pH values.
Received: 5 April 1998 · Accepted: 27 July 1998 相似文献
98.
Two waste-disposal sites (old and new) in Calabar Municipality, SE Nigeria were evaluated to assess their suitability as
landfill sites and their impact on the groundwater. The field investigation included surface geological/hydrogeological and
geochemical studies. Leachate and groundwater were sampled and analysed for 3 months (April, May and June, 1997) for geochemical
characterisation. The results indicate that the two waste-disposal sites in the Calabar Municipality do not meet the requirements
as landfill sites. Physico-chemical analyses for temperature, pH, conductivity, dissolved oxygen, biological oxygen demand
after 5 days of incubation (BOD5), sulphate, nitrates, nitrite, trace and major elements in the leachate known to impact human health and the environment,
indicate high levels of pollution. The values for groundwater in the vicinity of the disposal sites were found to be within
the World Health Organisation (WHO) permissible limit.
Received: 29 March 1999 · Accepted: 3 January 2000 相似文献
99.
100.