污水厂污泥一体化竖式强化渗滤浓缩自然干化与消化研究

针对目前国内污泥处理处置存在的问题,为实现污泥浓缩消化一体化,开发了污泥一体化强化渗滤浓缩自然干化与消化新工艺反应器,并进行了城市污水厂污泥处理试验。结果表明,在有机负荷为0.8 kg VSS/(m3.d)、平均水力停留时间为8.3 d、污泥停留时间为120 d的条件下,污泥有机物去除率可达到44.4%,排泥含水率达到79.1%,污泥消化与浓缩过程起到了相互促进的作用。渗滤液须抽回至污水处理厂处理。

自然干化赤霞珠葡萄酒的生产及风味特征分析

介绍了干化葡萄酒生产中原料自然干化处理的方法,并对原酒进行香气感官特征量化分析,以及采用顶空固相微萃取结合气质联用技术,对自然干化赤霞珠葡萄酒的风味特征进行了分析。结果表明,葡萄果穗在枝条上自然干化,总糖达到了275g/L;自然干化赤霞珠葡萄酒原酒的花香类、烘培类和香料类的香气特征的MF值相比普通赤霞珠葡萄酒原酒的MF值分别提高了16.7%、144.1%、204.1%。采用顶空固相微萃取结合气质联用技术,共检测出62种风味物质,主要为呈现出花香、水果香气、香料类香气、乳制品香气的化合物。

生物沥浸污泥深度脱水后自然干化与焚烧处置效果及影响因素

脱水污泥的干化效果对污泥后续焚烧处置及资源化有重要影响。比较了生物沥浸处理后深度脱水污泥与常规脱水污泥的水分蒸发速率差异,以评价其干化效果。在此基础上,对城市污泥生物沥浸示范工程中得到的有机质含量为44%(干物质计),干基高位热值为9 250 kJ/kg,含水率≤32%,颗粒粒径≤8 mm的污泥样品,采用小型循环流化床焚烧炉(内径600 mm,高度6 500 mm,污泥给料量200 kg/h)进行焚烧处置初步研究。结果表明,在同样干化时间下,生物沥浸后脱水污泥相对于常规脱水污泥有较快的水分蒸发速度。在保证污泥颗粒在流化床炉内达到较好的流化状态前提下,该生物沥浸污泥可以在流化床炉内实现自持焚烧,相应流化床炉温可以被恒定维持在850℃左右。焚烧后残渣热灼减率为2.36%。同时发现,污泥有机质含量、污泥含水率、污泥的颗粒破碎度、流化床布风板风量等因素共同决定着城市污泥的自持焚烧效果。此研究将为城市污泥生物沥浸后期焚烧资源化应用提供必要的参数支持及合适的运行建议。

覆膜人工滤层干化床处理城市污泥的试验研究

通过一体化竖式强化渗滤自然干化与消化反应器的现场试验,考察覆膜人工滤层干化床处理镇江征润州污水处理厂剩余污泥的效果并对其进行评价。干化床的滤层由50cm厚的砾石层[粒径分别为(4～8)、(10～20)、(50～80)mm,相应的厚度分别为10、20、20cm]构成。结果表明:干化床截留了98.5%的固体物质和99.9%的细菌,污泥产量为0.036m3干泥/m3生污泥,渗滤液体积占进泥量的74.4%;污泥含水率降至86%,有机质含量为40%,可对其进行堆肥化处理。建议在气候干爽、土地资源丰富的地区采用覆膜人工滤层干化床处理污泥。

污泥干化技术的应用现状

污泥干化是利用热物理的原理对污泥中的水分进行排除,从而达到干燥污泥、缩小污泥体积、提高污泥热值的目的。应用自然热源的干化过程称为自然干化,主要包括污泥干化场、太阳能干化床、生物干化和芦苇干化床。使用人工热源的干化过程为人工干化。本文对各种干化技术的应用现状进行了详细的介绍,以期为污泥干化技术的比较与选择提供指导。

小城镇污水处理厂污泥处理方法探讨

我国小城镇污水主要是生活污水,其污水厂规模小、污泥产量少。按城市污水厂污泥处理系统需要较大的投资和运行费用,传统的方法不适合小城镇资金少、专业技术人员缺乏、设备维修不方便的现状。污泥经自然干化后堆肥还田可利用污泥中有效成分,实现减量化、无害化、稳定化和资源化,且投资少、运行费用少、操作简单,制成的污泥肥料腐熟程度好、肥效高,是比较适合小城镇污泥处理的有效方法,具有广阔的应用发展前景。

水位变动较大河道环保疏浚与底泥处置方案

为解决水位变动较大河道的环保疏浚与底泥处置问题,基于山美水库进库河道段疏浚工程,总结如何合理地选择疏浚时机,采用适合特定水位下的疏浚设备统筹施工,利用太阳能自然干化降低底泥含水率,从而提高生产效率、节约成本,为后续工程提供经验借鉴。

Contributions of anthropogenic and external natural forcings to climate changes over China based on CMIP5 model simulations

Based on observations and historical simulations from the fifth phase of the Coupled Model Intercomparison Project(CMIP5) archive, the contributions of human activities(including greenhouse gases(GHGs), anthropogenic aerosols(AAs), and land use(LU)) and external natural forcings(Nat) to climate changes in China over the past 50 years were quantified. Both anthropogenic and external natural forcings account for 95%–99% of the observed temperature change from 1951–1975 to 1981–2005. In particular, the temperature changes induced by GHGs are approximately 2–3 times stronger than the observed changes, and AAs impose a significant cooling effect. The total external forcings can explain 65%–78% of the observed precipitation changes over the past 50 years, in which AAs and GHGs are the primary external forcings leading to the precipitation changes; in particular, AAs dominate the main spatial features of precipitation changes in eastern China. Human activities also dominate the long-term non-linear trends in observed temperature during the past several decades, and, in particular, GHGs, the primary warming contributor, have produced significant warming since the 1960 s. Compared to the long-term non-linear trends in observed precipitation, GHGs have largely caused the wetting changes in the arid-semiarid region since the 1970 s, whereas AAs have led to the drying changes in the humid-semihumid region; both LU and Nat can impose certain impacts on the long-term non-linear trends in precipitation. Using the optimal fingerprinting detection approach, the effects of human activities on the temperature changes can be detected and attributed in China, and the effect of GHGs can be clearly detected from the observations in humid-semihumid areas. However, the anthropogenic effects cannot be detected in the observed precipitation changes, which may be due to the uncertainties in the model simulations and to other issues. Although some results in this paper still need improvement due to uncertainties in the coupled models, this study is expected to provide the background and scientific basis for climate changes to conduct vulnerability and risk assessments of the ecological systems and water resources in the arid-semiarid region of China.