鞍山市南沙河综合整治改造工程建设与生态恢复浅谈

水利工程建设是我国工程建设的重要组成部分,如何保证工程在取得社会效益的同时,减少生态系统破坏是个重要的问题。本文在简要总结了南沙河综合整治工程建设状况的同时,对工程建设过程中保护生态系统的一些方法做了探讨。     

自动监测系统建设应该注意的几个问题

水质自动监测系统由中心站和水质自动监测子站组成,在全国范围内已经得到了广泛的应用。当地环境监测部门有责任对自动监测系统的建设进行参与和监督。本文分别从水质自动监测系统基础建设前期、基础建设时期、系统建设时期、试运行等各个阶段指出了系统建设应注意的问题。     

天津市供销社再生资源回收体系建设纪实

天津市供销合作总社全力打造天津市再生资源回收利用网络体系,对天津市供销合作总社再生资源行业的基本情况、历史沿革及近期重点工作进行介绍,分析了工作中存在的问题,并提出今后工作设想。为推进天津市再生资源回收体系建设,起到引领和示范作用。     

水资源系统风险构成及其评价——以北京市为例

论文在综合考虑系统属性、风险过程后,基于致险、承险因子及损害程度构建了水资源系统风险的评价指标体系及模型。该指标体系由4层次共20个指标构成,能更好地表征风险的产生和构成。评价模型包括参数计算与风险分级,能简便计算风险参数及因子贡献率并进行相应的风险级别划分。随后运用上述指标体系及模型,评价了北京市面临的水资源系统风险,结果表明主要致险因子是缺水率(0.426 1),主要的承险因子是水资源保障程度(0.647 6);若单考虑致险情况下的风险,北京市面临57.13%的致险率,在综合考虑水资源承险能力后得到风险为26.97%,显示北京市能较好应对水资源系统风险,但仍受约束性风险限制,可通过开源节流、调整产业结构及规范水资源管理来应对。     

基于农户层次的陕北黄土丘陵区农业生态经济系统耦合关系研究

农业生态经济系统耦合是一个复杂的过程,是潜变量与潜变量、潜变量与可测变量及可测变量之间相互作用的结果,结构方程模型的建立很好地描述了这一复杂关系。通过对吴起县、安塞县和宝塔区共建的中尺度生态农业建设试验示范区、米脂县等3个典型区域所代表的黄土丘陵区及其各个区域农业生态经济系统结构方程模型的建立与运算,结果表明:在"退耕还林还草工程"等外力作用下,农业生态经济系统运行模式基本揭示了农业产业与农业资源相互耦合这一本质规律,但现状耦合模式并未充分利用农业资源,系统耦合效果较低。农业产业与农业资源对系统耦合的影响系数分别为0.54和0.16,农业产业和农业资源之间的相关系数只有0.28,即农业资源没有很好地支撑产业的发展,导致农业生态经济系统耦合效果不明显,存在着局部相悖的态势,潜伏了林草资源与其相关产业链网缺失现象。为此,需要强化农业产业与农业资源的互动过程,特别要发展林草及其相关产业,促进林草资源的有效利用,促使系统耦合效果的不断提高,增加经济效益。     

太湖流域不同管理模式的社会经济环境系统演化模拟

基于复杂自适应系统理论构建了社会经济环境系统模型,采用计算实验方法模拟分析了太湖流域在经济优先和水环境保护优先2种管理模式下的动态演化过程,得到了农业与工业经济发展水平、就业状况和水环境改善情况的演化规律.结果表明,在综合考虑社会、经济、水环境的基础上,2种管理模式均能在一定程度上实现经济和就业的增长,同时改善水环境.环境保护优先模式虽能有效保护水环境,却会牺牲部分经济发展和就业保证.不同地区在演化过程中表现出差异性,常州和湖州经济获得较快增长;苏州、上海在就业方面做出较大贡献;无锡和苏州水环境改善效果最为明显.     

Classification of different sustainable flood retention basin types

Using a revised version of a previously published expert classification system, a database of potential Sustainable Flood Retention Basins has been developed for Scotland. The research shows that the majority of small and former (often old) drinking water reservoirs are kept full and their spillways are continuously in operation. Utilising some of the available capacity to contribute to flood control could significantly reduce the costs of complying with the European Union Flood Directive. Furthermore, the application of a previously developed classification model for Baden in Germany for the Scottish data set showed a lower diversity for basins in Scotland due to less developed infrastructure. The classification system appears to be robust and has the potential, with minor modifications, to be applied across Europe. The principle value of this approach is a clear and unambiguous categorisation, based on standard variables, which can help to promote communication and understanding between stakeholders.     

Treatment of oilfield produced water by anaerobic process coupled with micro-electrolysis

Treatment of oilfield produced water was investigated using an anaerobic process coupled with micro-electrolysis (ME), focusing on changes in chemical oxygen demand (COD) and biodegradability. Results showed that COD exhibited an abnormal change in the single anaerobic system in which it increased within the first 168 hr, but then decreased to 222 mg/L after 360 hr. The biological oxygen demand (five-day) (BOD5)/COD ratio of the water increased from 0.05 to 0.15. Hydrocarbons in the wastewater, such as pectin, degraded to small molecules during the hydrolytic acidification process. Comparatively, the e ect of ME was also investigated. The COD underwent a slight decrease and the BOD5/COD ratio of the water improved from 0.05 to 0.17 after ME. Removal of COD was 38.3% under the idealized ME conditions (pH 6.0), using iron and active carbon (80 and 40 g/L, respectively). Coupling the anaerobic process with ME accelerated the COD removal ratio (average removal was 53.3%). Gas chromatography/mass spectrometry was used to analyze organic species conversion. This integrated system appeared to be a useful option for the treatment of water produced in oilfields.     

Physiological responses and detoxific mechanisms to Pb, Zn, Cu and Cd in young seedlings of Paulownia fortunei

Paulownia fortunei has been successfully used in the phytoremediation of many Pb/Zn mine tailings. However, seed germination and young seedlings of P. fortunei rarely occurred in these mine tailings. The physiological responses and detoxific mechanisms of P. fortunei young seedling to Pb, Zn, Cu and Cd stress were investigated. The germinated rate, shoot length, chlorophyll and carotenoid contents in leaves of young seedlings had a great reduction under Zn and Cu treatments, but had little decrease under Pb and Cd treatments. The production rate of O₂^•−, H₂O₂ and malondialdehyde (MDA) contents significantly increased in response to added Zn and Cu indicating great oxidative stress for young seedlings, but they had no significant change to added Pb and Cd. Young seedlings had effective detoxific mechanism to Pb and Cd, as antioxidant enzymes activities, phytochelatins (PCs-SH) and proline contents increased with increasing rates of added Pb and Cd. However, young seedlings had un-effective detoxific mechanisms to Zn and Cu stress. Results revealed the heavy metals (such as Cu) that present at low concentrations in mine tailings may be major constraint for the survival of young seedlings.     

Degradation of acid fuchsine by a modified electro-Fenton system with magnetic stirring as oxygen supplying

The current modified electro-Fenton system was designed to develop a more convenient and e cient undivided system for practical wastewater treatment. The system adopted a cathode portion that employed magnetic stirring instead of common oxygen gas di usion or gas sparging to supply oxygen gas for the electrolyte solution. Key factors influencing the cathode fabrication and activity were investigated. The degradation of acid fuchsine with a self-made graphite-polytetrafluorethylene cathode was studied using a spectrophotometer. It was found that the cathode generated hydrogen peroxide with high current e ciency and the hydrogen peroxide yield of the cathode did not decay after 10 times reuse. With the Pt anode at a ferrous ion concentration of 0.5 mmol/L, a pH of 3, and using magnetic stirring, dye decolorization could be rapidly accomplished but the destruction of benzene rings and intermediates was fairly di cult. With a Fe anode, dye degradation was more complete.