城市污泥热解中试系统集成一体化研究及运行效果评估

为了促进城市污泥热解工艺的工程化应用,组建了污泥热解系统、热解产物分离回收利用系统、废气净化排放系统于一体较完整的热解中试装置,在实现污泥有效处置的同时也实现了高值能源回收利用。中试工况优化,较好工况为：热解时间30-40 min,热解终温450-500℃,在此条件下,干化污泥（含水率5%）减量率为50%;热值为33.8 MJ/kg的热解油产率为17.1%左右。通过对中试运行效果的评估,得出热解油和热解气两者能量或污泥炭自身能量可供干化污泥热解本身所需能量,从而为推动污水污泥热解工艺的工程化利用提供了支持。     

污泥与底泥烧结陶粒骨料的中试研究

建立了中试研究生产线,工艺流程包括干燥、粉磨、混合上料、成型、烧结和烟气处理等,在中试生产线上,对污泥(包括工业污泥(ISS)和生活污泥(DSS))与底泥烧结制备陶粒骨料的物料配比、烧结温度、添加剂等相关技术参数进行了系统研究。研究发现,ISS中CaO和磷的化合物含量较高,导致骨料的膨胀性能不佳,添加一定量的生活污水污泥(DSS)可改善骨料的膨胀性能。中试研究确定600～800级的陶粒骨料烧结的适宜工艺条件为:配比SS∶DSS∶RS=1∶4∶5～1∶5∶4或DSS∶RS=3∶7～5∶5,烧结温度1 140℃,烧结时间28 min环境安全性研究表明,在陶粒烧结过程中大部分重金属在烧结过程中被固定在陶粒中,重金属浸出率非常低,在使用过程中不会对环境产生危害。     

推流式反应器厌氧消化浮萍和猪粪混合物

使用带隔板的推流式反应器(体积约为4 m3),对浮萍与猪粪(干重比1:1,湿重比7:1)的混合物、猪粪进行为期50 d的中温厌氧消化产气性能比较研究,结果表明,在有机负荷为3.5 g(VS)/(L·d)时,浮萍与猪粪(干重比1:1,湿重比7:1)混合物的VS产气率为0.31 L/g,COD转化率为63.2％,反应器容积产气率为1.00 m3/(m3·d);猪粪的VS产气率为0.28 L/g,COD转化率为57.1％,反应器容积产气率为0.71m3/(m3·d).进料COD和SS的平均浓度分别为19.19 g/L和14.28 g/L,推流式反应器对其平均去除率分别为59.7％和68.7％.由此说明,带隔板的推流式厌氧反应器对浮萍和猪粪的混合物有较好的厌氧消化能力,浮萍与猪粪混合物的厌氧消化性能优于猪粪.     

Fate of atrazine in a soil under different agronomic management practices

Agricultural management affects the movement of atrazine in soil and leaching to groundwater. The objective of this study was to determine atrazine adsorption in a soil after 20 years of atrazine application under agronomic management practices differing in tillage practice (conventional and zero tillage), residue management (with and without residue retention) and crop rotation (wheat-maize rotation and maize monoculture). Atrazine sorption was determined using batch and column experiments. In the batch experiment, the highest distribution coefficient K_d (1.1 L kg^?1) at 0–10 cm soil depth was observed under zero tillage, crop rotation and residue retention (conservation agriculture). The key factor in adsorption was soil organic matter content and type. This was confirmed in the column experiment, in which the highest K_d values were observed in treatments with residue retention, under either zero or conventional tillage (0.81 and 0.68 L kg^?1, respectively). Under zero tillage, the fact that there was no soil movement helped to increase the K_d. The increased soil organic matter content with conservation agriculture may be more important than preferential flow due to higher pore connectivity in the same system. The soil's capacity to adsorb 2-hydroxyatrazine (HA), an important atrazine metabolite, was more important than its capacity to adsorb atrazine, and was similar under all four management practices (K_d ranged from 30 to 40 L kg^?1). The HA adsorption was attributed to the type and amount of clay in the soil, which is unaffected by agronomic management. Soils under conservation agriculture had higher atrazine retention potential than soils under conventional tillage, the system that predominates in the study area.     

光磁耦合废水处理工艺条件的优化研究

以Fe3O4/TiO2作为磁性光催化剂,采用光磁耦合技术处理模拟印染废水。利用统计学方法对光磁耦合废水处理的影响因素进行了探讨和分析,考察了磁场强度、磁性光催化剂投加量、pH值和光照时间对光磁耦合废水处理的影响。通过Design-Expert 7.0.0软件分析得到最佳工艺条件:磁场强度73.95 mT,磁性光催化剂投加量1.13 g/L,模拟废水pH值13,光照时间120 min。在最佳工艺条件下进行实验,脱色率为88.60%。     

Variation of reservoir fluid property during the high pressure air injection process

This research aimed at determining the variation of reservoir fluid property during the high-pressure air injection process. For this purpose, the forward multiple contact experiment was employed by pressure–volume–temperature (PVT) system to investigate the physical property variation of the crude oil and the complex oxidation reactions. The results show: under the relative low temperature and pressure condition, instead of carbon dioxide, carbon monoxide dominates the products in the air phase. The gas/oil ratio and volume ratio increased due to the generated gas while the viscosity and density achieved a descending trend. The colloid and bitumen in the oil phase reduced by half but the amount of wax achieved a small increase. The low-temperature oxidation and pyrolysis reactions caused the fluctuated change of the different compounds. The amount of light compounds decreased at the beginning and then increased while that of heavy compounds showed the opposite trend. But at last, due to the H/C ratio, the light compounds increased to more than their initial value.     

Fluid bed gasification – Plasma converter process generating energy from solid waste: Experimental assessment of sulphur species

Often perceived as a Cinderella material, there is growing appreciation for solid waste as a renewable content thermal process feed. Nonetheless, research on solid waste gasification and sulphur mechanisms in particular is lacking. This paper presents results from two related experiments on a novel two stage gasification process, at demonstration scale, using a sulphur-enriched wood pellet feed.Notable SO₂ and relatively low COS levels (before gas cleaning) were interesting features of the trials, and not normally expected under reducing gasification conditions. Analysis suggests that localised oxygen rich regions within the fluid bed played a role in SO₂’s generation. The response of COS to sulphur in the feed was quite prompt, whereas SO₂ was more delayed. It is proposed that the bed material sequestered sulphur from the feed, later aiding SO₂ generation. The more reducing gas phase regions above the bed would have facilitated COS – hence its faster response. These results provide a useful insight, with further analysis on a suite of performed experiments underway, along with thermodynamic modelling.     

煤及煤矸石中砷的释放

研究了煤及煤矸石中砷的释放特征。采用XRD技术对煤样中的主要矿物成分进行了分析。表征结果显示,煤样中的主要矿物组成为碳酸盐矿物、硅酸盐矿物,以及一定量的SiO2、TiO2、硫化物矿物和硫酸盐矿物。实验结果表明：煤中砷的赋存形态主要以残渣态和硫化物结合态为主;在煤燃烧过程中,当燃烧温度为1 000 ℃时,1号矿井的煤样燃烧后灰渣中的砷含量为1.385 μg/g,砷的释放率为40.10%,2号矿井的煤样燃烧后灰渣中的砷含量为1.531 μg/g,砷的释放率为56.04%;在煤矸石的淋溶过程中,在淋溶液体积为100 mL的条件下,当淋溶液pH为5时淋出液中的ρ（砷）为19.27 μg/L,当淋溶液pH为7时淋出液中的ρ（砷）为7.78 μg/L。     

度量生态服务价值的选择实验:方法介绍及案例研究

选择实验作为一种价值评估工具,自1990年代以来被应用于生态环境和自然资源利用领域。选择试验不同于开放式或封闭式条件价值法中采用的那种直接出价方式,它实际上模拟了一个关于不同水平属性组合的交易市场。由于选择实验可以评价生态环境和自然资源利用的某一属性,所以这一方法更适合作为生态补偿政策的评估工具。选择实验基于特征效用理论和随机效用理论,该方法成功的关键是选定合适的属性及其水平。设计选择实验目前最有效的方法是D-效率设计,这一设计要求的原则是水平平衡,正交性,最少重叠,以及效用平衡。作为案例研究,本文利用选择实验计算了资兴东江湖雾的景观价值。将影响东江湖旅游这一产品的效用和价值的主要属性确定为雾、其他自然景观、设施以及门票,其中门票价格是成本属性。数据由课题组实地通过问卷调查获得。计算结果是,相对于无雾,东江湖游客愿意支付132.93元看到小雾,支付136.59元看到仙境雾。本文还计算出让其他自然景观维持现状、变好的支付意愿分别为151.84、198.98元,让道路及旅游服务设施变得更好的支付意愿是28.43元。     

长江中下游人工鱼礁水动力特性实验研究

受三峡蓄水的影响,长江中下游水文生态系统发生明显变化,导致四大家鱼产卵适宜度下降以及像中华鲟这类生殖洄游性鱼类鱼卵孵化率降低。建设人工鱼礁是缓解长江渔业资源衰退、保护长江物种多样性、保持长江渔业可持续发展的一项重要措施。基于水槽模型实验,以透空正六面体型人工鱼礁为研究对象,将鱼礁块体与护岸相结合铺设在河道岸坡上,构成鱼礁型生态护岸。通过对鱼礁型护岸周围水面线及水流流速等水力特性进行测量分析,得到了鱼礁型护岸的鱼类产卵场水力因子。结果表明:在长江中下游河道两岸铺设透空型人工鱼礁其周围水流流速可维持在0.84~1 m/s之间,处于四大家鱼产卵繁殖最适宜的流速范围内;且由于鱼礁的存在,使岸坡附近水流流速梯度增大并产生上升流及背涡流等一些复杂的水流流态,这些水力因素又刺激了四大家鱼的交配活动,增加鱼类的产卵量。