煤制氢含氰废水的处理工艺研究

采用混凝—光催化氧化(UV-NaClO或UV-H_2O_2)组合工艺处理某石化企业煤制氢生产中排放的含氰废水,并在实验室研究(小试)的基础上进行了放大规模试验(中试)。小试结果表明:混凝工段的适宜工艺条件为不调节混凝pH、混凝剂投加量200 mg/L;相同氧化剂投加量下H_2O_2溶液氧化降解氰化物的能力较NaClO溶液强,后者虽可将总氰化物质量浓度降至1 mg/L以下,但氧化剂消耗量过大。经反复试验和综合分析,将中试工艺改进为沉降—UV-H_2O_2工艺。中试结果表明:采用沉降—UV-H_2O_2工艺处理含氰废水,处理效果显著且稳定,处理成本低廉(约为8元/m3),值得推广。     

Water shortage and inequality in arid Minqin oasis of northwest China: adaptive policies and farmers’ perceptions

Minqin oasis, located at the lower reaches of the Shiyang River in northwest China, is one of the driest regions in the world. Severe water shortage has exacerbated the vulnerability of local ecosystems and the agricultural livelihood of farmers, and ecological failure threatens the environmental security of the region. Since 2007 China has implemented a range of strategic programmes and policies on water management which involve governments at all levels and include a diversity of adaptive actions in this region. However, rural households do not benefit equally from the policies and programmes. This study addresses two questions: first, how are inequality issues addressed in water-related policies and programmes? And second, what demographic and socio-economic factors at the household level are significantly related to the inequality in benefit sharing arisen from the implementation of these policies? The study employs a mixed method approach, integrating a qualitative approach that investigates policy documents with a quantitative approach that analyses primary data collected from a household survey in Minqin in 2012. The study finds that there are inadequate financial and instrumental resources put in place to address the causes of inequality. Unequal holdings of household capital, especially social capital and political status, significantly influences whether or not farmers can benefit from the water-related policies and schemes as practiced in the study area. Addressing the root causes of unequal benefits from water-related policies is urgent if China aims to achieve policy goals and sustainable development in this ecologically vulnerable region.     

吡唑醚菌酯对不同阶段斑马鱼的毒性效应评价

为评价吡唑醚菌酯对鱼类不同生命阶段的毒性效应,以斑马鱼(Brachydanio rerio)为测试生物,测定了其对斑马鱼胚胎、仔鱼(孵化3 d和孵化12 d)和成鱼的急性毒性及对胚胎和仔鱼(孵化3 d)的发育毒性。结果表明,吡唑醚菌酯对斑马鱼胚胎、仔鱼(孵化3 d)、仔鱼(孵化12 d)和成鱼的96 h-LC50分别为0.0578(0.0540~0.0631)、0.0299(0.0282~0.0320)、0.0330(0.0310~0.0350)和0.0756(0.0692~0.0862)mg·L-1,其毒性大小依次为仔鱼(孵化3 d)仔鱼(孵化12 d)胚胎成鱼。与对照组相比,吡唑醚菌酯0.101 mg·L-1处理,可对斑马鱼胚胎24 h自主运动产生显著抑制作用;0.0609、0.0777和0.101 mg·L-1处理,可对斑马鱼胚胎48h心跳速率产生显著抑制作用;0.0609和0.0777 mg·L-1处理,可对斑马鱼胚胎96 h孵化仔鱼体长产生显著抑制作用。在供试浓度下吡唑醚菌酯暴露96 h后,均可对斑马鱼仔鱼(孵化3 d)体重和体长产生明显的抑制效应,对斑马鱼仔鱼(孵化3 d)心跳未产生明显影响。在高浓度下,吡唑醚菌酯可诱导斑马鱼胚胎产生畸形,主要包括心包水肿、卵黄囊水肿等;而对仔鱼(孵化3 d)未观察到明显的致畸效应。     

Living with climate change risks: stakeholders’ employment and coastal relocation in mediterranean climate regions of Australia and Spain

Climate change impacts are no longer just a future issue for communities in the Mediterranean climate regions. This comparative study offers insights on climate change risk perceptions and attitudes among environmental, economic and social stakeholders in coastal areas in northeastern Spain and South Australia, as well as compares interviewed stakeholders’ risk perceptions with available documentary data and participant observation. Using a community risk assessment approach, the results show that some stakeholders perceive that climate change is already and/or may further continue to affect their employment, mostly in a predominantly negative way. Interestingly, some other interviewed stakeholders consider that climate change creates opportunities through new and additional areas of work. The findings also suggest that climate change may influence relocation of coastal residential populations in both case studies, which is likely to be an acceptable option among the stakeholders. This acceptance can be linked to the fact that in both areas there is a significant percentage of resident population with migrant background. This study calls for a need to understand better the personal experience of climate change in industrialized countries, as well as to consider coastal relocation in the integrated coastal planning and other territorial and population policies.     

电化学法消毒处理医院污水的试验研究

采用电化学法消毒处理医院污水,通过选用不同阳极材料构建的电化学体系,探讨电化学法的消毒机理.试验表明,以涂有贵金属(钌、铂和铱)氧化物的钛板作阳极,不锈钢板作阴极,在电流密度为8 mA/cm2、水力停留时间为15 min、空气流量为40L/h、极水比为1.0的试验条件下,消毒后污水中总大肠菌群数＜500 cfu/L,达到国家一级排放标准(GB8978-1996).     

基于BP模型的降雨酸度预测方法研究与应用

将通过同步观测实验系统获得的影响降雨酸度的主要大气污染物和气象参数观测结果作为自变量,降雨酸度作为因变量,建立了基于BP神经网络模型的降雨酸度预测模型。并通过设定天津市区未来环境空气中TSP、SO_2和NO_2的浓度变化情景,运用本研究所建立的BP网络模型进行情景分析。结果表明,降雨酸度随着TSP浓度的减小而增强,随着降雨量的增大也在增强;当TSP浓度降低到几十微克每立方米水平时,天津市区所发生的降雨属于酸雨的可能性将大大增加。     

Hydrological connectivity and <Emphasis Type="Italic">Burkholderia pseudomallei</Emphasis> prevalence in wetland environments: investigating rice-farming community’s risk of exposure to melioidosis in North-East Thailand

In our analysis of 136 water samples from wetland environments (rice paddies, natural wetland sites, man-made water bodies) in rural areas of North-East Thailand, Burkholderia pseudomallei was most prevalent in rice paddies (15 of the 30 positive sites). The high prevalence in the water of rice fields is indicative of the inherent vulnerability of farmers in rural agricultural areas in this area of Thailand and likely other locations in the tropics. Nearly all B. pseudomallei-positive sites were found within the vicinity of a large wetland associated with the Chi River, in the month of July 2014. Positive samples were found in water ranging in pH from 5.9 to 8.7, salinity ranging from 0.04 to 1.58 ppt, nitrate ranging from 0 to 10.8 ppm, and iron ranging from 0.003 to 1.519 ppm. Of these variables, only iron content was statistically higher in B. pseudomallei-positive versus B. pseudomallei-negative sites, suggesting that increasing concentrations of iron may encourage the growth of this bacterium, which is responsible for melioidosis. Our results, when combined with data from other published studies, support the notion that B. pseudomallei can exist in a wide range of environmental conditions. Thus, we argue that health safety education is a more appropriate means of addressing farmer vulnerability than chemical or physical alterations to fields at large scales. Further, it may be important to investigate melioidosis through transdisciplinary approaches that consider the complex social and ecological contexts in which the disease occurs.     

制革厂铬鞣废水中铬的回收处理研究

针对制革厂铬鞣废水含铬(Cr3 )量高、成分复杂、沉淀后铬泥纯度低的问题,本实验采用优化后的直接加碱沉淀法、絮凝后再加碱沉淀法和新型的硅铁电极法来回收铬鞣废水中的铬.3种方法所得铬泥的纯度分别在36%、65%和80%以上,比原铬泥纯度(27.7%)最多提高了近2倍.     

成型膨润土和钛柱撑膨润土对水中Pb2+和氯乙酸吸附及再生

针对水中微量铅离子和氯乙酸的脱除,考察了成型膨润土及成型钛柱撑膨润土的吸附性能,得出对铅离子的吸附,成型膨润土、成型钛柱撑膨润土与粉末状活性炭性能相当,而对氯乙酸的吸附前两者要比粉末状活性炭低好多.确定了成型膨润土吸附氯乙酸后可用沸水煮沸30 min的方法再生,成型钛柱撑膨润土吸附氯乙酸后,可用500℃焙烧3 h的方法再生,再生的膨润土循环使用3次后性能降低明显.此外,还测得了成型的膨润土及成型的钛柱撑膨润土吸附铅离子和氯乙酸的等温线,计算出其对铅的最大吸附量分别为24.33 mg/g和15.47 mg/g.