Mitigation effects of silicon rich amendments on heavy metal accumulation in rice (Oryza sativa L.) planted on multi-metal contaminated acidic soil

The mechanisms of stabilization by silicon-rich amendments of cadmium, zinc, copper and lead in a multi-metal contaminated acidic soil and the mitigation of metal accumulation in rice were investigated in this study. The results from a pot experiment indicated that the application of fly ash (20 and 40 g kg⁻¹) and steel slag (3 and 6 g kg⁻¹) increased soil pH from 4.0 to 5.0-6.4, decreased the phytoavailability of heavy metals by at least 60%, and further suppressed metal uptake by rice. Diffusion gradient in thin-film measurement showed the heavy metal diffusion fluxes from soil to solution decreased by greater than 84% after remediation. X-ray diffraction analysis indicated the mobile metals were mainly deposited as their silicates, phosphates and hydroxides in amended treatments. Moreover, it was found metal translocation from stem to leaf was dramatically restrained by adding amendments, which might be due to the increase of silicon concentration and co-precipitation with heavy metals in stem. Finally, a field experiment showed the trace element concentrations in polished rice treated with amendments complied with the food safety standards of China. These results demonstrated fly ash and steel slag could be effective in mitigating heavy metal accumulation in rice grown on multi-metal contaminated acidic soils.     

环境在线监控数据交换系统的设计与应用

根据环境在线监控的数据特征和普遍存在的问题,提出了针对环境在线监控数据交换的系统设计方案,包含数据交换中心、前置系统、发布过程安全的设计。该系统可实现污染源(固定源、移动源)、水环境、大气环境、生态环境、辐射环境等各类在线监控数据的自动归集、交换和集成。为各级环保部门同时、准确地掌握各种在线监控数据,提高监管能力提供技术支撑。     

基于PD的无阀滤池工程设计参数化系统

将参数化设计(PD)应用到无阀滤池工程设计参数化系统的开发中,分析了其参数化设计过程及其优点。通过参数化设计,将无阀滤池工程设计过程的效率提高了大约80%,同时设计过程更加人性化和智能化。     

PCDD/Fs in ambient air in north-east Italy: The role of a MSWI inside an industrial area

The stack gases of a municipal solid waste incinerator (MSWI), and ambient air were sampled in four locations around the plant for the analysis of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/Fs). The sampling area was close to an industrial area near Trieste, in north-east Italy. The purpose of the study was to estimate the impact of the MSWI emissions and to distinguish the contribution of these emissions from other potential emission sources in the industrial area.PCDD/F atmospheric concentrations were similar to those generally detected in urban–rural areas with one location about 2–3 times more contaminated than the others. Since the most contaminated location was inside the industrial area but upwind of the MSWI, principal component analysis (PCA) was used to establish whether other sources were the cause. This analysis clearly showed that a local steel plant’s emission was the main source of PCDDs/Fs in ambient air. This study highlights the usefulness of multivariate data analysis such as PCA to identify, among different potential emission sources, the one really responsible for the contamination.     

管线钢应力腐蚀机理的研究现状

综述了管线钢在不同环境下应力腐蚀开裂(SCC)行为与机理的研究现状.介绍了高pH-SCC的保护膜破裂-裂尖阳极溶解机理;重点分析了近中性pH-SCC的阳极溶解(AD),氢脆机制(HE),AD与HE混合机制等3种开裂机理;强调了AD与HE混合机制在近中性pH-SCC的重要作用.     

生物活性炭深度处理和回用钢铁工业废水

针对钢铁工业废水的水质特点,采用生物活性炭工艺对钢铁工业达标排放的废水进行深度处理试验.结果表明,在生物活性炭滤柱滤速为1.6 m/h、停留时间为45 min的运行工况下,生物活性炭对钢铁工业废水中的浊度、铁、锰均有较高的去除率,出水水质达到《城市污水再生利用工业用水水质》(GB/T19923-2005)要求.     

钢结构暨空间结构的抗火设计综述

钢结构暨空间结构是目前建筑结构的重要发展方向之一。因钢材对高温的敏感性 ,其防火、抗火性能的研究应是设计时考虑的重要因素。笔者简述了抗火与防火的概念及其区别 ;评估了国内外关于抗火设计的基本方法及优缺点 ;重点对整体结构有限元非线性抗火反应全过程分析方法进行了讨论。通过选择科学的抗火设计方法 ,将为经济、适用的防火设计提供重要的依据     

地下水环境监测系统的设计

介绍了地下水环境监测的现状，特点和设计地下水环境监测系统的目的，详细阐述了地下水环境监测系统的站位布设，采样频率和时间分配，监测项目，以及地下水采样井的布设。     

区域地表水监测断面优化调整的技术方法

对中国地表水水质监测断面布设的现状及问题进行分析,简要回顾了中国地表水监测断面设置及优化的研究进展,论述了区域地表水点位优化的目的和原则,提出从宏观、中观、微观3个层次的对区域地表水监测断面进行调整的步骤和方法,并阐述了地理信息系统技术在监测断面优化中的作用。