广东白石嶂钼矿环水利用及尾矿处理工艺的改进

广东白石嶂钼矿选厂生产运行时,φ53 m浓密池中的尾矿浆浓度高,难以沉降,选矿工艺流程供排水量和浓密池矿浆流量不平衡,造成环水水质差、尾矿处理效率低等问题.针对该现状,采取了一系列的改进措施.通过稀释尾矿至浓度15％ ～20％、添加絮凝剂非离子型聚丙烯酰胺溶液(0.5‰)+聚合氯化铝溶液(1‰)15 +30 g/t,提高了浓密池的尾矿浆沉降速度和底流浓度,显著改善了溢流水质;通过改造浓密池与搅拌桶之间的回浆管道等措施提高尾矿处理效率,同时完善工艺技术措施,较好地解决了尾矿处理、选矿环水利用存在的问题,为矿山持续稳定生产创造了有利条件.

水利水电规划环境影响评价不确定性分析及应对措施探究

由于水利水电规划环境影响评价存在一定的不确定性,不仅影响生态环境,也影响水利水电工程的正常运行,为此,本文利用蒙氏模拟算法计算出水利水电规划环境风险概率,并将其转变为不确定性问题求解,以此完成水利水电规划环境影响评价不确定性分析,并给出相应的应对措施,以降低水利水电规划环境影响评价的不确定性,增强水利水电的环保性。

强化尾矿系统技改增强选矿环保效果

针对梅山选矿一期生产过程中层矿系统存在的环保问题，总结选矿二期建设和生产中层矿系统技术改造后，提高环水利用串和矿山环保的成效。

金矿矿区水工环地质灾害危险性评估方法

随着我国经济不断的发展,人们的生活水平有了明显的提高,但是由于过度的采矿,地质被严重的破坏,严重影响了人们的日常生活。根据我国可持续发展的战略部署,对金矿矿区的建设进行水利环地质灾害的危险性评估,并且保证施工方案科学性的基础上,制定金矿矿区水利环地质灾害危险性评估方法。本文通过大量详细的户外勘察以及室内试验,发掘出影响水利环地质灾害的内在条件。通过对水利环地质灾害危险性评估方法的深入研究,达到对金矿矿区水利环地质灾害危险性的全面认识。

水工环地质在地质灾害治理中的应用

由于国内经济社会逐渐进步,导致在生态环境开始逐渐被破坏的更加迅速,而且此趋势不止是对于整个生态造成了影响,更加严重的是对地表下地质的破坏,如果没有将在地质灾害的治理落到实处,将会使得地质灾害走向更为严重的后果,因此必须将治理工作提上日程。在此期间,为确保治理工作的有效,需要一些必要的技术给予帮助,其中,最为关键的便是水工环地质技术,借助于此技术是比较重要的一个手段,相应水工环地质勘察技术的应用更是可以表现出较强的工作实效性,对于后续地质灾害治理提供较强参考资料,该方面的研究具备较强价值意义。

Potential contributions to Beijing's water supply from reuse of storm-and greywater

In order to find new approaches to alleviating the water crisis in Beijing which is caused by among others dwindling precipitation and rapid growth of population and manifests in a rapidly declining groundwater table this study explores decentralized stormwater harvesting and greywater reuse at household level as a means to reduce groundwater abstraction and water transfer from other regions.Based on a desktop case study two concepts for combined harvesting and reusing of storm-and greywater are presented.With rough pre-assumptions calculations show that a saving of 67.8%of tap water consumption can be achieved with the upgrading concept compared with 5.9% with the simple downgrading concept.The saving with the upgrading concept equals 0.545 ×109 m3 annual water volume if 20 million Beijing people apply this approach.Despite numerous prerequisites such as water treatment technology space demand energy and cost and public acceptance this paper advocates combining stormwater harvesting and greywater reuse in households with other measures for Beijing’s sustainable water management.

Humble View on Soil Water Resources

Soil water is one of renewable water resources.Some properties of soil water concerning with its availability to plant are briefly described.An equation for estimating the amount of soil water resource is presented.Based on the evaporation demand of atmosphere,the evaluation coefficient for soil water resource is suggested.

Nitrogen Status and Utilization in Rhizosphere of Rice

A greenhouse pot experiment was conducted with hybrid rice (Ocyza Sativa L.) in order to stndy Nstatus and utilization in the rhizosphere of rice. The experiment was composed of three treatments: withoutN, ￣(15)NH_(4-) N and ￣(15) NO_(3-) N. Plant roots were separated from the soil by a nylon cloth, and 1 mm incrementsof soil, moving laterally away from the roots, were taken and analyzed for various N froms. The labelled Nin the plants ranged from 67.51% to 69.24% of the total amount of N absorbed by the rice seedlings withthe labelled fertilizer N treatments. This shows that the N in the plants came mainly from the fertilizers.However, the N absorbed by the rice seedlings accounted for less than 35% of the total amount of the Ndepletion in the soil near the rice roots, indicating an important N loss in the rhizosphere of rice. The soilredox potential (all treatments) and the concentration of the labelled NO_3-N (the labelled NH_(4-_)N treatmentonly) decreased as the distance from the rice roots increased in the rhizosphere of rice. In contrast, theconcentration of the labelled NH_(4-) N increased a.s the distance increased in the same soil zone. These resultssuggested that nitrification occurred in the soil around the rice roots. Therefore, the reason for the N lossin the rhizosphere of rice might be the NO_3 movement into the reductive non-rhizosphere soil (submerged)where denitrification can take place.

Pyropia yezoensis can utilize CO_2 in the air during moderate dehydration

Pyropia yezoensis, an intertidal seaweed, experiences regular dehydration and rehydration with the tides. In this study, the responses of P. yezoensis to dehydration and rehydration under high and low CO2 concentrations （（600-700）×10^-6 and （40-80）×10^-6, named Group I and Group II respectively） were investigated. The thalli of Group I had a significantly higher effective photosystem II quantum yield than the thalli of Group II at 71% absolute water content （AWC）. There was little difference between thalli morphology, total Rubisco activity and total protein content at 100% and 71% AWC, which might be the basis for the normal performance of photosynthesis during moderate dehydration. A higher effective photosystem I quantum yield was observed in the thalli subjected to a low CO2 concentration during moderate dehydration, which might be caused by the enhancement of cyclic electron flow. These results suggested that P. yezoensis can directly utilize COz in ambient air during moderate dehydration.

High-rate removal of As(Ⅲ) from aqueous system with sulfhydryl magnetic biological bamboo charcoal nanocomposites prepared by chemical co-precipitation method

Sulfhydryl magnetic biological bamboo charcoal nanocomposite(BBC@nFe-SH)was prepared by chemical co-precipitation method for the robust capture of As(Ⅲ)from aqueous solutions.The novel BBC@nFe-SH shows favorable magnetic field strength(83376 A/m),which enables BBC@nFe-SH to be quickly recovered from aqueous solution.The maximum As(Ⅲ)adsorption capacity is as high as 98.63 mg/g at pH 5.0 and 40°C,reaching reaction equilibrium within 120 min.Various characterizations(e.g.,SEM,FTIR,VSM and XPS)suggest that As(Ⅲ)prefers to coordinate with surface oxygen groups bonded to the surface.BBC@nFe-SH displayed high stability and recyclability throughout the removal process,which could be easily activated by 1 mol/L NaOH after usage.Thus,the novel BBC@nFe-SH has promising applications for As(Ⅲ)treatment.

Study on the Definition and Allocation of the Rights to Water Utilization in the Ecological Environment

With the rapid development of population and economy, the conflict between the supply and demand of water resources is becoming outstanding increasingly, In China, many people concern about the problems of ecological environment water expenditure.However, owning to the shortage of water resources and indefinite water rights, “the hustle effect” of per capita water resource is appeared, Moreover. it caused a series of environment problems. This article differentiates and analyzes the relevant concepts about the ecological enviromnent, and puts forward the defined concept of the rights to the ecological environment water utilization. In addition, it points out the characteristic of those rights, and does elementary study on the allocation principle, methods, and steps on the rights.

State Space Approach to Mass Exchange Network Synthesis

State space approach is an effective method to mass-exchange network (MEN) synthesis. By decomposing the network into two interactive parts, a distribution network and a process operator, the synthesis problem can be formulated into a mixed integer nonlinear programming (MINLP) model. In this article, a generalized state space model based on typical MEN is established and verified in two cases. A new asymmetrical operator and cost index are also adopted to speed up the solution process. The results demonstrate the efficiency of the proposed approach.

Phosphorus Biogeochemical Cycle Research in Mountainous Ecosystems

Phosphorus(P),as a limiting nutrient,plays a crucial role in the mountainous ecosystem development.Its biogeochemical cycle in mountainous ecosystems determines the bioavailability and sustainable supply of P,and thus becomes a crucial process which needs to be fully understood and described for ecological and environmental conservation.However,most of research about P biogeochemical processes has been carried out in aquatic environment and agronomic field,but rare researches have been done in mountain ecosystem.In the present review,we summarize researches on P biogeochemical cycle concerning mountain ecosystem in recent decades,including rock weathering,the release,transformation and bioavailability of P,interactions between the P biological cycle and microbial and plant life,as well as the development of models.Based on the state of art,we propose the future work on this direction,including the integration of all these research,the development of a practical model to understand the P biogeochemical cycle and its bioavailability,and to provide a reference for ecological and environmental conservation of mountainous ecosystems and lowland aquatic systems.

Feasibility analysis and implementation of marine ranching integration of offshore wind power development in Guangdong Province

Marine ranching is a new model for restoring marine ecological environment and conserving offshore fishery resources.Offshore wind power is a new clean energy industry in China.Based on the analysis of the construction of offshore wind farms in Guangdong Province,this article proposes to actively promote the integrated development of offshore wind power and marine ranching.The suitability and deployment conditions of Sargasso algae reef construction in offshore wind farms,the feasibility of developing an integrated development model featuring artificial algae reefs+offshore wind farms in Guangdong Province,as well as the importance of ecological sea area use and management were discussed.Regarding the necessity of intensive and economical utilization of sea and sea resources,it is believed that the development model of"marine ranching+offshore wind power"will become an important direction for improving the comprehensive utilization of sea areas in the future.

Florida Springs--A Water-Budget Approach to Estimating Water Availability

Florida＇s artesian springs receive groundwater outflows from the Floridan Aquifer System and are concentrated north of I-4 and west to the Florida Panhandle. These springs and their resulting spring runs support a unique freshwater ecology dependent on perennial flows, constant temperature and chemistry, and high light transmissivity. Numerous observations indicate that Florida＇s springs flows are declining as a result of the increasing extraction of groundwater for human uses. North Florida＇s karst environment is especially susceptible to nitrogen pollution from agricultural and urban development. An empirical springs/aquifer water budget is needed to better understand these spring stressors. Discharge data from 393 of the state＇s 1,000＋ artesian springs are used to estimate trends in total spring discharge by decade since 1930-39. This analysis indicates that average spring flows have declined by about 32%. Large groundwater pumping centers are altering spring flows over the whole springs region. Existing groundwater pumping rates from the Floridan Aquifer in 2010 were more than 30% of average annual aquifer recharge, and allocated groundwater use in north-central Florida is nearly double current estimated uses. Based on biological research conducted in Florida springs, these flow reductions are from two to six times greater than declines known to result in significant harm to aquatic resources.

Study on the Exploitation of Bohai Sea Ice as Freshwater Resources

Water shortage is a major issue in northern China. With the transfer of China＇s economic center from south to north, Circum-Bohai Economic Circle has gradually formed and developed as the third pole of China＇s economy after Yangtze River Delta and Pearl River Delta, the problem of water has inevitably become more and more serious. South-to-North Water Diversion and Sea Water Desalination are helpful to solve this dilemma, but some difficulties appeared during the course of the two projects. By contrast, sea ice desalination can be considered as a third way to alleviate freshwater crisis in Bohai Rim. Firstly, the amount of sea ice in Bohai Sea is as much as 1.27 billion m3 even in normal years. Then the salinity of sea ice is only 1/4 to 1/7 as that of sea water. And furthermore, desalinized water of sea ice can meet national water quality standard for drinking. Purposely use the abundant sea ice resources as water source for industry, agriculture and living is very likely to open a new path for the solution of freshwater shortage, which can promote rapid and healthy development of Circum-Bohai Economic Circle.

Qualitative and Environmental Aspects Study of Water Distributed in West Algeria： The Case of Sidi Bel Abbes City

Water comes from various different sources, such as lakes, rivers, streams, springs and boreholes. Depending on the quality of its source, water will almost certainly have to be treated to make it safe to drink. All water supplies for human consumption must be well stored, free from micro-organisms, parasites and any substances that endanger public health if found in sufficient numbers or concentrations, in the same time. In our continued effort for a better result in our study of qualitative aspects, by physicochemical and bacteriological analysis, the authors focus in two crucial questions： a） is the water quality of Sidi-bel-Abbes good or bad ,and well stored？ b） is the people of Sidi-bel-Abbes are aware of the importance of water and knowledgeable about how to use this vital？ This study is the first to use data from I real work based upon a developed method and a good investigation to know exactly if water of Sidi-Bel-Abbes is safely treated, well stored and consumed in resemble way. In first, the authors plotted the method in analysing the qualitative aspect of water using developed material for a precise result starting by the distribution connection （condition and management） and the verification of water tank storage and finishing by analyzing the all the aspect of water （physicochemical and bacteriological analysis）. In second, the authors focus on the way that people of Sidi Bel Abbes used and consumption water by introducing a targeted method （questionnaires） which help us a lot to know precisely the way, time and the real quantity of water consumed daily. In final step of our study of qualitative aspects, by physico-chemical and bacteriological, and environmental analyses, investigation processed by PCA （principal component analysis） of the drinking water supplied to Sidi Bel Abbes city （Algeria north-west） concluded by an encouraging result, that despite the various constraints faced by the departments concerned, they ensure the supply of safe drinking water in households almost daily.

RECOVERY AND DESTRUCTIVE TREATMENTOF HARMFUL SUBSTANCE IN COKING PLANT WASTEWATER

This paper discussed the comprehensive treatment of coking plant effluent.Cyanide containing and phenol wastewater was first recovered and utilized respectively, and then, mixed it with other low harmful wastewater for destroying treatment.Treated water was reused in quenching coke.

Genotypic variations in nitrogen use efficiency of rice cultivars at various levels of nitrogen under subtropical environment

Insufficient N supply is an important constraint to productivity of lowland rice. Studies on N nutrition of rice cultivars with different durations representing the north western part of Indo-Gangetic Plains are scanty. A field experiment was conducted during kharif seasons of 2006 and 2007 at PAU, Ludhiana to assess the differences in grain yield and N utilization of three popular rice cultivars at varying N doses. Significant differences among genotypes were observed in grain yield, N uptake, N use efficiency and N utilization efficiency. The cultivar PAU-201 was found to be superior among all the tested genotypes. Total N uptake and grain N uptake was highest in cultivar PAU-201 followed by cultivars PR-115 and PR-113. On an average, the response to applied N for grain yield was observed upto 90 kg N ha1. Grain yield increased significantly up to 90 kg N hal in cultivars PR-115 and PAU-201 and up to 120 kg N ha1 in PR-113. Apparent recovery efficiency （ARE） and Partial factor productivity （PFPN） of N was significantly reduced at higher level of N （150 kg N hal）. It was concluded that N uptake is predominant factor in grain yield formation and cultivars differ in NUE suggesting that it may be possible to develop cultivars that are efficient at low nutrient level or are capable of using N more efficiently when applied as fertilizer.