曝气生物活性炭滤池深度处理垃圾渗滤液的效能研究

为了考察曝气生物活性炭滤池(BACF)深度处理垃圾渗滤液的效能,研究了填料填充度、曝气位置、气水比、水力停留时间和p H等影响因素对滤池去除有机物、氨氮和总氮的影响。结果表明,最佳的工艺运行条件为:填料填充度为80%,底部曝气,气水比为3:1,水力停留时间为8 h,p H为7~8。在最佳工艺条件下运行反应器,COD、氨氮和TN平均去除率分别达到85%、90%和57%,出水可达到实验设定水质要求。BACF具有较强的抗有机负荷能力,进水COD浓度在323至3 000 mg/L之间时,COD去除率稳定在80%。反应器受氨氮冲击负荷影响较大,氨氮进水浓度低于90mg/L时,出水可达到要求。     

膨润土负载壳聚糖吸附剂处理染料废水的实验研究

利用膨润土负载壳聚糖吸附处理结晶紫染料废水,考察了pH值、搅拌时间和膨润土负载壳聚糖吸附剂的用量等对结晶紫去除率的影响。结果表明,当pH值为5,搅拌时间为30min,膨润土负载壳聚糖吸附剂投加量为500mg时,处理50mL浓度为5×10^-4mol／L染料废水的结晶紫去除率达到99．5％。     

曝气生物滤池处理生活污水的试验研究

对升流式二级曝气生物滤池去除COD和NHs—N的效果进行了试验研究,并在各个阶段对比中找出最优的运行工况,从而达到节约能源,降低运行成本的目的。通过试验对水力负荷、有机负荷、气水比等参数的变化对去除COD和NH3-N效果的影响。研究结果表明,在进水水力负荷为1～4m3／m^2·h、有机负荷为4-13kgCOD／ms·d及气水比1：1～3：1的工艺条件下,COD和NH3-N的出水水质均能满足杂用水需要。     

天然麦饭石负载TiO2的光催化性能研究

采用溶胶-凝胶法制备了二氧化钛负载于天然麦饭石表面热处理后得到复合光催化剂TiO2/麦饭石,并通过N2吸附-脱附、XRD及IR对其进行表征。探讨了以天然麦饭石为载体制备具有较高光催化活性的负载型TiO2/天然麦饭石复合物的各种影响因素:焙烧温度,加投量,pH值等。研究结果表明:200℃焙烧条件下TiO2/麦饭石复合物具有最大的光催化活性,达到了纯TiO2的光催化效果:对罗丹明B脱色率随着光催化剂增多而增大;对罗丹明B在pH值7～9时具有最大的降解率,开拓和优化TiO2光催化效能的新途径。     

Nutrients and suspended solids in dry weather and storm flows from a tropical catchment with various proportions of rural and urban land use

The results of an investigation characterizing the nutrients and suspended solids contained in stormwater from Kranji Catchment in Singapore are reported in this paper. Stormwater samples were collected from 4 locations and analyzed for the following eleven analytes: TOC, DOC, TN, TDN, NH₄⁺, NO₂⁻ + NO₃⁻ (NO_x), TP, TDP, OP, SiO₂ and TSS. Stormwater was sampled from catchments with various proportions of rural and urban land use, including forested areas, grassed areas, agricultural and residential and commercial areas. The event mean concentrations (EMCs) of nutrients and TSS from sampling stations which have agricultural land use activities upstream were found to be higher. Comparison of site EMCs (SMCs) with published data showed that the SMCs of the nutrients and TSS are generally higher than SMCs reported for forested areas but lower than published SMCs for urban areas. Positive correlations (p < 5%) were found between loading and peak flow at locations most impacted by ubanisation or agricultural activities. Correlation between loading and rainfall variables was less distinct. EMC was found to correlate less with rainfall and flow variables compared to pollutant loading. Unlike loading, no consistent pattern exists linking EMC to any particular storm or flow variable in any of the catchments. Lastly, positive correlations were obtained between the particulate forms of nitrogen and phosphorus and TSS.     

Modeling watershed-scale effectiveness of agricultural best management practices to reduce phosphorus loading

Planners advocate best management practices (BMPs) to reduce loss of sediment and nutrients in agricultural areas. However, the scientific community lacks tools that use readily available data to investigate the relationships between BMPs and their spatial locations and water quality. In rural, humid regions where runoff is associated with saturation-excess processes from variable source areas (VSAs), BMPs are potentially most effective when they are located in areas that produce the majority of the runoff. Thus, two critical elements necessary to predict the water quality impact of BMPs include correct identification of VSAs and accurate predictions of nutrient reduction due to particular BMPs. The objective of this research was to determine the effectiveness of BMPs using the Variable Source Loading Function (VSLF) model, which captures the spatial and temporal evolutions of VSAs in the landscape. Data from a long-term monitoring campaign on a 164-ha farm in the New York City source watersheds in the Catskills Mountains of New York state were used to evaluate the effectiveness of a range of BMPs. The data spanned an 11-year period over which a suite of BMPs, including a nutrient management plan, riparian buffers, filter strips and fencing, was installed to reduce phosphorus (P) loading. Despite its simplicity, VSLF predicted the spatial distribution of runoff producing areas well. Dissolved P reductions were simulated well by using calibrated reduction factors for various BMPs in the VSLF model. Total P losses decreased only after cattle crossings were installed in the creek. The results demonstrated that BMPs, when sited with respect to VSAs, reduce P loss from agricultural watersheds, providing useful information for targeted water quality management.     

Predicting future effects from nutrient abatement and climate change on phosphorus concentrations in Lake Bourget, France

Like many temperate European lakes, Lake Bourget (France) has suffered from eutrophication during the second half of the last century. Due to a remarkable restoration program, the lake has been recovering for the past 25 years after a massive decrease in total phosphorus (TP) loading. TP concentrations have decreased from about 100-120 to 20-25 μg/L. Additional efforts are, however, still required to obtain a perennially sustainable good ecological status and model parameterisation of fluxes can assist in predicting future outcomes, especially in the context of global warming. In this paper, a dynamic model (MeroLakeMab) was developed and tested with the purpose to reconstruct the loading history of Lake Bourget and to predict TP concentrations during scenarios of increased temperature, decreased water runoff and decreased P loading. Simulations suggested that the historical TP loading decrease may have been as extensive as 88%. Decreases in water discharge to Lake Bourget at magnitudes forecasted by the Intergovernmental Panel on Climate Change (IPCC) would not affect TP concentrations notably, but marked concentration changes could, however, occur if decreases in runoff would have a strong impact on the TP loading. Increasing temperature effects on yearly mean TP concentrations in the water column would be very small compared to effects from changes in the TP loading. Predictions such as these could be instrumental for future successful lake management.     

Development of a loading dock safety evaluation tool

INTRODUCTION: Companies that use forklifts to load and unload trucks at loading docks are well aware of the main danger associated with this type of activity (i.e., the possibility of the forklift falling or tipping over when the truck suddenly moves away from the dock). Even if various truck restraint measures can be implemented to reduce the possibility of this type of accident, a number of hazardous incidents that result in a forklift tipping over from a loading dock still do occur regularly in day-to-day activities. This situation has brought experts to examine and evaluate the effectiveness of different measures and systems depending on the context in which they are used. METHODS: The present study touched upon both the technical and the organizational aspects of the restraint measures that could have an impact on safety. Certain elements were examined very closely, especially the failure of mechanical devices and their relation to the environment in which they are used, as well as the systemic interaction between people and the various restraint measures in use in a given context. CONCLUSION: This article presents a safety evaluation tool regarding restraint measures or systems for trucks docked at loading platforms - a tool that, of course, would take into consideration both the specific contextual aspects related to the docking bay itself, and to the plant. IMPACT ON INDUSTRY: This tool is designed to help companies choose the optimal safety measures to implement, while remaining realistic in terms of the technical and economic aspects of any given situation.     

液化石油气站装卸连接装置改造的安全隐患分析

针对目前液化石油气站内装卸软管已强制要求改装为液体装卸臂的现状,本文梳理了原质监部门和安监部门对液化石油气站内装卸连接装置的不同要求,对在用液体装卸臂改造存在的安全隐患和后续的监管问题进行了分析,并对液体装卸臂的改造和监管提出了几点建议.