微波加热快速测定环境水样中的CODMn

利用微波加热技术,在密闭容器内压力消解,用高锰酸钾法快速测定了西流湖水、黄河水等环境水样和标准水样(CW82,中国环境监测总站)中的COD_(Mn),并与经典方法进行了对照测定,结果令人满意。本法十几分钟内可消解十几个样品,Cl_-离子含量高达1000mg/L时亦不产生干扰,COD_(Mn)的检测下限为0.26mg/L,上限为15.0mg/L,室内测定的RSD<4％,多次加标回收率在97.0～105.6％之间,标准水样测定结果的相对误差为0.3％。适用于轻度污染水体COD_(Mn)的批量分析。     

Hydrophobic calcium carbonate: an option for the value-added conversion of wastes resulting from biodiesel production

High production cost is the key issue of biodiesel industry nowadays. To low down the cost, using low-quality lipids feedstock is the most effective way. Two-step process is vastly applied to deal with those low-quality lipids to produce biodiesel. However, environmentally unfriendly wastes are formed during the process. Here we use calcium oxide residue and wastewater from biodiesel production to produce nanostructured calcium carbonate (CaCO₃) by carbonation at ambient temperature. The results show that CaCO₃ is hydrophobic and has broccoli-like morphology. It is made up of many uniform nano-rods, and each rod is composed of smaller particles with diameters about 50 nm. The idea of wastes utilization could make the biodiesel production process environmentally friendly, and the income of the produced CaCO₃ could further low down the cost of biodiesel production.     

周期性风温下矿井巷道围岩换热教学实验装置研制

为开展矿井热害防治的实验教学,设计并搭建周期性风温作用下巷道非均质围岩换热实验装置,能直观展示高温围岩各岩层的温度变化.利用实验数据可计算出巷道壁面热流密度,进而定量估算巷道围岩的散热量.结果表明:周期性风温通过后,模拟巷道围岩体各处温度随时间也呈简谐波变化;对于非均质的围岩体,导热系数越大的岩层,周期性风温的调热能力...     

我国农村化粪池污染物去除效果及影响因素分析

探究农村化粪池污染物去除效果及主要影响因素对于理解我国农村化粪池粪污处理现状十分必要.本研究基于山西、陕西、浙江、湖南、广东和重庆6个选点区域57家农户化粪池的监测结果,分析了农村化粪池处理污染物的现状和主要影响因素.结果表明,区域化粪池对化学需氧量(COD)、5日生化需氧量(BOD5)、氨氮(NH3-N)、总氮(TN...     

一株生长pH较宽的产甲烷菌分离与系统发育分析

采用Hungate厌氧操作技术.从造纸厂阴沟污泥中分离到一株生长pH范围为5.5～9.5的产甲烷菌株SH4.该菌对酸碱具有良好的适应性,培养3 d后,在初始pH值6.0～8.0的培养基中甲烷产量相差不大,且基本达到最大产量.SH4革兰氏染色阳性,短杆状,多数单生,不运动;菌落近圆形,微黄;利用H2+CO2或甲酸盐作为唯一碳源生长,不利用乙酸盐,对氯霉素非常敏感.该菌最适生长pH为7.0,最适生长温度为35 oC,最适NaCl浓度为0～1.5%.实验表明,与仅添加厌氧污泥作为接种物相比,添加SH4菌液可使产甲烷启动时间缩短1/3,甲烷总产量亦有大幅提高.形态、生理生化特征以及16S rDNA序列分析表明,该菌为嗜树木甲烷短杆菌(Methanobrevibacter arboriphilus).图8参16     

乙二胺基棉纤维脱硫剂的制备研究

通过氯化和胺化两步反应合成了乙二胺基棉纤维（AEAC）,并用于模拟烟气中SO₂的吸附研究。试验比较研究了不同种类的氯代试剂、胺化反应稀释剂和溶胀试剂对乙二胺基棉纤维制备和脱硫性能的影响。结果表明：乙二胺基棉纤维能有效吸附烟气中SO₂,饱和吸附容量可达120 mg/g干纤维;以N,N-二甲基甲酰胺(DMF)作为溶胀试剂,三氯氧磷(POCl₃)作为氯代试剂,并以正丁醇为胺化反应稀释剂可以大大改善乙二胺基棉纤维脱硫吸附剂的合成效果;样品含氮量和饱和硫容之间存在很好的正相关关系。     

Depletion of chlortetracycline during composting of aged and spiked manures

Chlortetracycline (CTC) is one of the most important pharmaceuticals occurring in the environment. An increase of its application as feed supplement for livestock and poultry in the world leads to a substantial CTC contamination of manures, because most of the CTC is excreted to manure. The simulation experiment of aerobic composting was adopted to investigate CTC depletion in aged and spiked manure composting, and to address the extent of CTC depletion during composting. The results showed that the extractable CTC initial concentration was markedly different between the different manures, with 94.71mgkg(-1) in broiler manure and 879.6mgkg(-1) in hog manure. The concentration of extractable CTC decreased rapidly at the initial stage of composting, and subsequently declined slowly during aged and spiked manure composting. At the end of composting, more than 90% of CTC in the manure composting process (42 days) was depleted, except for hog manure composting with a removal of only 27%. The CTC half-lives were 11.0 days in broiler manure, 86.6 days in hog manure, 12.2 days in layer-hen manure (150.3mgkg(-1) CTC), 12.0 days in layer-hen manure (100.0mgkg(-1) CTC) and 4.39 days in layer-hen manure (53.10mgkg(-1) CTC), all according to the first order kinetics. The significance of experimental parameters in CTC depletion was assessed by the Pearson correlation approach. Microbial degradation of CTC was not effective from manure composting. CTC depletion was in good correlation with total organic carbon, total nitrogen, total phosphorus, C/N, N/P and total heavy metals.     

Modelling coordination in hospital emergency departments through social network analysis

Coordination theory provides a theoretical framework for analysing complex processes of project groups working towards a common goal. In this study, we explore the relationship between coordination and social networks for the development of a network-based coordination model. This model is applied to measure the performance and quality of complex and dynamic project coordination such as in hospital emergency departments. The dataset used for the study was collected by the 2004 National Hospital Ambulatory Medical Care Survey--a national probability sample survey of visits to emergency and outpatient departments of non-Federal, short-stay and general hospitals in the United States. Using social network analysis, this study allows us to understand the possible causes of inefficient coordination performance and coordination quality resulting in access blocks.     

Rural domestic waste management in Zhejiang Province,China: Characteristics,current practices,and an improved strategy

Lack of access to adequate sanitation facilities has serious health implications for rural dwellers and can degrade the ecosystems. This study offers a systemantic and quantitative overview of historical data on rural domestic waste (RDW) production and past and current management practices in a prototype region in China, where rural areas are undergoing rapid urbanization and are confronted with great environmental challenges associated with poor RDW management practices. The results indicate that RDW is characterized with a large fraction of kitchen waste (42.9%) and high water content (53.4%). The RDW generation (RDWG) per capita between 2012 and 2020 is estimated to increase from 0.68 to 1.01 kg/d-cap. The Hill 1 model is able to adequately simulate/project the population growth in a rural area from 1993 to 2020. The annual RDWG in the region is estimated to double from 6,033,000 tons/year in 2008 to 12,030,000 tons/year by 2020. By comparing three RDW management scenarios based on the life-cycle inventory approach and cost–benefit analysis, it is strongly recommended that the present Scenario 2 (sanitary landfill treatment) be upgraded to Scenario 3 (source separation followed by composting and landfill of RDW) to significantly reduce the ecological footprint and to improve the cost-effectiveness and long-term sustainability.

Implications:?Rural domestic waste (RDW) is affecting 720 million people in China and more than 3221 million people worldwide. Consequently, handling and disposal of RDW have serious health implications to rural dwellers and the ecosystems. This study offers a systemantic and quantitative overview and analysis of historical data on RDW production and management practices in a prototype region in China, which is confronted with great environmental challenges associated with RDW. Then we predict future production of RDW and propose a sustainable RDW management strategy, which holds the promise of greatly mitigating the mounting environmental pressure associated with RDW and provides science-based guidance for decision makers and practitioners for assuring rapid yet “green” economic development.     

低密度聚乙烯悬浮接枝马来酸酐工艺废水的回用

在低密度聚乙烯悬浮接枝马来酸酐(MAH)的工艺过程中,分别采用工艺废水直接回用和补加MAH及相应添加剂后再回用的两种回用方式对工艺废水进行资源化利用。实验结果表明,将工艺废水补加MAH及相应添加剂后回用于接枝物的制备过程,所得产物的接枝率稳定在1.30%以上,凝胶含量(质量分数)低于0.018%,熔融指数为10.22~10.37g/10min,产物性能与采用原配方制得产物相近。将工艺废水进行资源化利用,每生产1t接枝产物可节省MAH0.33t,共计节约成本2 880元。