共查询到20条相似文献,搜索用时 62 毫秒
1.
利用煤吸附处理含铬废水及生活污水的试验研究 总被引:4,自引:0,他引:4
本文研究了四川白皎无烟煤用于生活污水、含铬废水和乐果生产废水的处理。在静态条件下,煤对生活污水中的COD去除率为12%;对乐果生产废水的脱色率大于638%;在含铬工业废水在浓度为3526×10-5mol·dm-3时Cr(VI)的去除率为90%左右。考察了固液比、温度、浓度和酸度等对煤吸附Cr(VI)的影响,并发现吸附量q与时间t之间遵从如下的定量关系:q=47685(1+21256t)-1或q=21351[1-exp(-05016t)]03838 相似文献
2.
用分光光度法测定水中化学需氧量CODCr,通过正交试验选择氧化的最佳选择。试验结果表明对CODCr值为50~1000mg/L的水样:氧化剂K2Cr2O7用量为0.20~0.40mol/L,催化剂Ag2SO4用量为10g/LH2SO4,消解时间10min,加热温度180℃。用CODCr为138mg/L的质控标样进行验证试验,其绝对误差为0.5~3.0mg/L。与标准方法相比用分光光度法测定CODCr具有分析误差小,省时、省力,节约药剂的特点。 相似文献
3.
采用新型载体的好氧流化床的动力学研究 总被引:1,自引:0,他引:1
本文以稀释的味精废水为基质,对采用新型载体LSAR的好氧生物流化床进行动力学研究,求得动力学参数分别为γmax=8.81(gCOD/gvs.d),Ks=0289(gCOD/L),Kd=0.046d^-1,Y=0.16(gvs/gCOD)。其值基本处于文献的报导之内,说明以LSAR为载体的好氧微生物膜具有较好的活性,LSAR作为好氧流化床载体是可行的。 相似文献
4.
5.
氯离子浓度高于500mg/L时,对CODcr的测定呈混浊干扰,通过加入HgSO4络合氯离子,可消除氯离子含量达2000mg/L的干扰,过量的HgSO4对CODcr结果无影响。 相似文献
6.
测定污水中CODcr回流时间的探讨肖建寅,吴平胜(珠海市政管理处,珠海519015)化学需氧量(ChggiCCIOXygenDemand,简称COD)是指水体中易被强氧化剂氧化的还原性物质所消耗氧化剂的量,结果折算成氧的量(以mg/L计)。而以酸性介... 相似文献
7.
8.
9.
10.
为了探讨火电厂除灰水中的粉煤灰(含炉渣)对炼油厂含碱污水中石油类、COD(cr)等污染物的吸附处理效果,根据某单位现场情况,将炼油厂含碱污水送入火电厂除灰沟→经充分混合排入储灰场→并经长时间沉降分离的流程进行模拟试验,结果表明:由于粉煤灰的吸附作用,显著降低了炼油厂含碱污水中的石油类、COD(cr)、挥发酚、碳化匕物等污染物。 相似文献
11.
Gabriele Villarini Enrico Scoccimarro Kathleen D. White Jeffrey R. Arnold Keith E. Schilling Joyee Ghosh 《Journal of the American Water Resources Association》2015,51(5):1361-1371
Our improved capability to adapt to the future changes in discharge is linked to our capability to predict the magnitude or at least the direction of these changes. For the agricultural United States Midwest, too much or too little water has severe socioeconomic impacts. Here, we focus on the Raccoon River at Van Meter, Iowa, and use a statistical approach to examine projected changes in discharge. We build on statistical models using rainfall and harvested corn and soybean acreage to explain the observed discharge variability. We then use projections of these two predictors to examine the projected discharge response. Results are based on seven global climate models part of the Coupled Model Intercomparison Project Phase 5 and two representative concentration pathways (RCPs 4.5 and 8.5). There is not a strong signal of change in the discharge projections under the RCP 4.5. However, the results for the RCP 8.5 point to a stronger changing signal related to larger projected increases in rainfall, resulting in increased trends, in particular, in the upper part of the discharge distribution (i.e., 60th percentile and above). Examination of two hypothetical agricultural scenarios indicates that these increasing trends could be alleviated by decreasing the extent of the agricultural production. We also discuss how the methodology presented in this study represents a viable approach to move forward with the concept of return period for engineering design and management in a nonstationary world. 相似文献
12.
Environmental assessment in countries in transition: evolution in a changing context 总被引:1,自引:0,他引:1
Cherp A 《Journal of environmental management》2001,62(4):357-374
Over the last fifteen years, Environmental Assessment systems of transitional societies of Central and Eastern Europe and Central Asia have undergone dramatic change from appraisals integrated into centrally planned economies to formal procedures aimed to ensure interdisciplinary analysis of environmental impacts and linked to publicly accountable decision-making. In most Central European nations, EA systems have been radically reformed to approximate the procedures used in developed countries, particularly in the European Union. In contrast, EA in most of the former Soviet republics has been reformed more gradually and is still based on the so-called State Environmental Review procedure inherited from the USSR and substantially different from 'Western' EA. About one-third of the transitional countries (in the Balkans, the Caucasus and Central Asia) have, so far, failed to establish functioning EA systems. Throughout the region, there has been a gap between EA legislation and practice, especially concerning interdisciplinary analysis of environmental impacts, public participation, and utilisation of EA findings in decision-making. A key driving force in the reform of EA systems has been the change in their societal context, the so-called 'process of transition'. Three main policy agendas--environmental protection, reforms of decision-making, and conforming to international requirements--along with the institutional context of EA regulations and practice have influenced both the change of EA systems over time and the regional variations in the patterns of their evolution. This study suggests that an effective reform of an EA system should be context-sensitive, or be 'in gear' with the political and economic transition. Future EA research should consider their changing societal contexts and focused on practical effects of applying EA procedures. 相似文献
13.
As a result of Structural Adjustment Programme from the 1980s, many developing countries have experienced an increase in resource extraction activities by international and transnational corporations. The work reported here examines the perceived impacts of gold mining at the community level in the Wassa West District of Ghana, Africa and discusses those perceived impacts in the context of globalization processes and growing multinational corporate interest in Corporate Social Responsibility (CSR). Interview data compared community members' perceptions with those of company representatives in three communities. The results indicate that communities held companies responsible for a series of economic, social, and environmental changes. While recognizing some of the benefits brought by the mines, communities felt that the companies did not live up to their responsibility to support local development. Companies responded by denying, dismissing concerns, or shifting blame. Findings from this work show that lack of engagement and action by government agencies at all levels resulted in companies acting in a surrogate governmental capacity. In such situations, managing expectations is key to community-company relations. 相似文献
14.
15.
Xinzhi Yu 《Journal of Environmental Planning and Management》2019,62(6):939-959
The preparation of strategic environmental assessment (SEA) inclusive sustainability appraisals (SAs) for neighbourhood plans (NPs) in England may be required when significant environmental effects are expected to arise from an NP. In this paper, we report on the result of a Ph.D. project, conducted between 2012 and 2015, in which all 15 NP SEA inclusive SAs that had been completed at the time were evaluated. In this context, the quality of SA practice was found to differ substantially. SAs were prepared either ‘in-house’ (i.e. by neighbourhood planning steering groups) or by consultants. The quality of SAs was found to be associated with their overall perceived degree of influence on the underlying NPs. Whilst the focus of this paper is on practice in England, findings are expected to be of interest to a wider international audience, in particular to those experimenting with voluntary neighbourhood/local level plan SA/SEA. 相似文献
16.
Yuriko Sakairi 《Natural resources forum》2000,24(4):313-323
This article presents a case study from Mozambique of the electrification of two selected towns under a World Bank financed project. Low-cost electricity services were extended to the two isolated areas after an enabling framework had been created for private sector participation. The World Bank project also demonstrates that the private sector can be attracted to participate in rural electrification schemes even in a poor country. The example shown in this article is one of the few of its kind in SubSaharan Africa. 相似文献
17.
18.
Environmental Flows (EFlows) are defined as the quantity, timing and quality of the flow of water, sediment and biota necessary to sustain freshwater and estuarine ecosystems, and the human livelihoods and well-being that depend on these ecosystems. As such they are a vital component of Integrated Water Resource Management (IWRM). A recent survey found that, in general, Africa lags behind schedule with respect to the global SDG Target 6.5 to implement IWRM at all levels, including through transboundary cooperation as appropriate. This web-based review explores progress made in EFlows Assessments and implementing their outcomes in southern Africa. It outlines the apparent impetus to the uptake of EFlows provided by legislation, common funding mechanisms for EFlows assessment and evolving trends in EFlows assessment. It also highlights instances of implementation of EFlows in both in-country and transboundary settings. 相似文献
19.
Rainfall samples were collected during the 2003 and 2004 growing seasons at four agricultural locales across the USA in Maryland, Indiana, Nebraska, and California. The samples were analyzed for 21 insecticides, 18 herbicides, three fungicides, and 40 pesticide degradates. Data from all sites combined show that 7 of the 10 most frequently detected pesticides were herbicides, with atrazine (70%) and metolachlor (83%) detected at every site. Dacthal, acetochlor, simazine, alachlor, and pendimethalin were detected in more than 50% of the samples. Chlorpyrifos, carbaryl, and diazinon were the only insecticides among the 10 most frequently detected compounds. Of the remaining pesticide parent compounds, 18 were detected in fewer than 30% of the samples, and 13 were not detected. The most frequently detected degradates were deethylatrazine; the oxygen analogs (OAs) of the organophosphorus insecticides chlorpyrifos, diazinon, and malathion; and 1-napthol (degradate of carbaryl). Deethylatrazine was detected in nearly 70% of the samples collected in Maryland, Indiana, and Nebraska but was detected only once in California. The OAs of chlorpyrifos and diazinon were detected primarily in California. Degradates of the acetanilide herbicides were rarely detected in rain, indicating that they are not formed in the atmosphere or readily volatilized from soils. Herbicides accounted for 91 to 98% of the total pesticide mass deposited by rain except in California, where insecticides accounted for 61% in 2004. The mass of pesticides deposited by rainfall was estimated to be less than 2% of the total applied in these agricultural areas. 相似文献