Progress and prospects of atmospheric environmental sciences in China: Preface

正Anthropogenic emissions impact significantly the atmospheric environment which human being relies on,e.g.,global warming,stratospheric ozone depletion,photochemical smog,acid rain,haze and so on.Although clean air actions have been legislated by many nations to mitigate pollutants’emission with the aim of protecting the atmospheric environment,     

危险化学品泄漏事故处置

为了降低危险化学品泄漏事故造成的损失和危害,本文系统介绍了危险化学品泄漏事故的应急处置措施,并根据泄漏物质的危险特性,分八大类介绍了不同物质的最简便、有效的泄漏处置方法.     

石化企业HSE管理平台设计与实现

阐述了石化企业HSE管理平台的设计思想和主要功能,介绍了HSE平台的特点.该平台的建立和运行,将提高企业安全管理的效率,使之更加科学化、系统化、规范化、制度化.     

The role of pH in the fermentative H2 production from an acidogenic granule-based reactor

The role of pH in the fermentative H(2) production from an upflow acidogenic granule-based reactor was investigated in this study. Experimental results show that all H(2) partial pressure, H(2) production rate and H(2) yield were pH-dependent, in the range of 2.8 x 10(4)-5.2 x 10(4)Pa, 61-145 ml-H(2)l(-1)h(-1) and 0.68-1.61 mol-H(2)mol-glucose(-1), respectively. The maximum H(2) partial pressure was observed at pH 3.4, while both maximum H(2) production rate and H(2) yield were found at pH 4.2. Acetate, propionate, butyrate, i-butyrate, valerate, caporate and ethanol were present in the effluent of this UASB reactor, and their distribution was also pH-dependent. As pH was decreased from 4.2 to a lower level of 3.4 or increased to a higher level of 6.3, the fermentative type of this H(2)-producing reactor would shift from butyrate-type to caporate- or ethanol-type. Thermodynamic analysis was performed to explore the possible metabolic pathways of caproate and valerate formation. The metabolic pathway of caproate formation was pH-dependent, while that of valerate formation was pH-independent. A neural network model was designed, trained and validated. It was able to successfully describe the daily variations of H(2) partial pressure and H(2) yield of the reactor, and to predict its steady state performance at various pHs.     

Environmental assessment of different advanced oxidation processes applied to a bleaching Kraft mill effluent

Basic research on remediation of polluted sediment by leaching has, to date, been carried out exclusively with suspended material. For economic reasons, only solid-bed leaching is applicable to large-scale processes. Abiotic and microbial solid-bed leaching were comparatively studied in a percolator system using ripened and therefore permeable heavy metal polluted river sediment. In the case of abiotic leaching, sulfuric acid was supplied to the sediment by circulating water; the lower the pH of the percolating water, the higher the percolation flow, and the lower the solid-bed height was, the faster the heavy metals were solubilized. However, the pH and percolation flow are subjected to restrictions: strongly acidic conditions result in dissolution of mineral components, and the percolation flow must not exceed the bed permeability. And a high solid bed is an economic requirement. In the case of bioleaching, elemental sulfur added to the sediment was oxidized to sulfuric acid within the package which, in turn, solubilized the heavy metals. Here, the percolation flow and the solid-bed height did not affect the rate of metal solubilization. Solid-bed leaching on a larger scale will thus be much more efficient applying bioleaching with sulfur as the leaching agent than abiotic leaching with sulfuric acid.     

Agronomic characterisation of different types of sewage sludge: Policy implications

Spain is one of the main municipal sewage sludge producers of Europe. This paper aims to agronomically characterise different types of sewage sludge stabilised by different methods (anaerobically digested, composted, and pelletised) and deliver policy recommendations from the results of this characterisation. Anaerobic sewage sludge quality is found to be better in plants with a lower volume of water processing. Composted sludge shows the best quality from a heavy metal point of view, but its low available nitrogen content increases the input of heavy metals when spread, as compared to digested or pelletised sludge. Pelletised sludge has higher heavy metal content than anaerobically digested sludge. Despite the good quality of the sludges, future regulations, especially with regard to Cd levels, will limit the use of this waste in agriculture.     

安全是最好的效益

有些人总认为安全投入增加生产成本,安全规定影响生产进度,安全或多或少的影响经济效益.其实不然,安全是最好的经济效益. 安全的经济效益可以从以下几个方面看出来:     

LIGNIN SEPARATION BY CONTINUOUS ION FLOTATION: INVESTIGATION OF PHYSICAL OPERATIONAL PARAMETERS1

ABSTRACT: Ion flotation is the term used to describe a process in which there is an initally homogeneous solution which becomes heterogeneous after the addition of an oppositely charged surfactant due to the reaction between the surfactant and specific ion(s); thus, insoluble complexes are formed. These insoluble complexes will then attached to the bubbles passing through the solution and thus leave in the foam phase. The performance of the continuous ion flotation process for the removal of haft lignin from water was investigated intensively using liquid flow rates, gas flow rates, feed locations and solution height as operational variables. The interrelationships among these physical parameters were studied and discussed. A dimensionless operational chart was established for process control. Results demonstrate that ion flotation is an effective process for removing lignin from water, provided that a quaternary ammonium salt, such as cetyldimethylbenzyl-ammonium chloride or the like, is used as a collector. At optimum operational conditions, higher than 0.95 fractional removal of lignin can be achieved.