甑皮岩洞穴遗址地下水的水-气界面H2S气体的产生机理

桂林甑皮岩洞穴遗址是我国新石器时代洞穴遗址的典型代表。污染物进入到以裂隙介质为主地下水所形成的还原环境后,其性质可能会改变从而侵蚀遗址文化层。本文通过采集地下水水-气界面的H₂S和CH₄气体,结合硫酸盐的硫同位素δ³⁴S-SO₄^2-、溶解有机碳（DOC）、化学需氧量（COD）、硫酸盐还原菌（SRB）等指标,研究遗址地下水水-气界面侵蚀性气体H₂S的产生机理。结果表明：甑皮岩水体SO₄^2-浓度范围为0.57~131.00 mg/L,其空间分布不均匀,来源主要受到大气降水、硫化物矿物的氧化及微生物硫酸盐还原的影响;丰富的有机质为硫酸盐还原提供能量,DOC与COD浓度存在空间差异,高值均位于人类活动强烈的径流上游区;SRB普遍参与硫酸盐还原作用,气温、降水和有机质决定SRB数量在时空上表现为雨季 > 旱季、地表水 > 地下水;气温较高促进H₂S的形成,SRB与环境的还原程度均影响H₂S和CH₄浓度。H₂S性质不稳定易氧化为硫酸,若继续聚集将加剧遗址的化学侵蚀。建议增加污染物的运移和反应产物的监测,关注遗址的保存环境。     

不同挂膜方式成熟滤料去除地下水中As(Ⅲ)研究

通过动力学和动态柱实验对比研究了不同挂膜方式成熟滤料去除地下水中As（Ⅲ）效能.并采用SEM-EDS?XRD及FTIR等表征手段对滤料形态和结构进行了分析.结果表明,两种滤料的形貌具有较大差异.采用化学挂膜的滤料去除As（Ⅲ）性能更优.二级动力学模型能较好地模拟两种滤料除As（Ⅲ）动力学过程,自然挂膜滤料和化学挂膜滤料拟合速率常数分别为8.568×10^-6和14.248×10^-6mg/（g·min）.Yan模型对动态柱实验穿透曲线的拟合系数R²>0.999.通过脱附再生实验,发现0.5mol/L的NaHCO₃作为脱附剂可使滤料有效再生.对比过滤前后滤料的XRD分析结果,滤料结构变化不大,除砷能力稳定.滤料表面铁锰氧化物含量直接影响滤料除As（Ⅲ）性能.两种滤料在除砷过程中均消耗了羟基.本研究为不同方法去除地下水中As（Ⅲ）提供了理论支撑,具有一定工程指导意义.     

Microbial growth and transport in porous media under denitrification conditions: experiments and simulations

Soil column experiments were conducted to study bacterial growth and transport in porous media under denitrifying conditions. The study used a denitrifying microbial consortium isolated from aquifer sediments sampled at the U.S. Department of Energy's Hanford site. One-dimensional, packed-column transport studies were conducted under two substrate loading conditions. A detailed numerical model was developed to predict the measured effluent cell and substrate concentration profiles. First-order attachment and detachment models described the interphase exchange processes between suspended and attached biomass. Insignificantly different detachment coefficient values of 0.32 and 0.43 day⁻¹, respectively, were estimated for the high and low nitrate loading conditions (48 and 5 mg l⁻¹ NO₃, respectively). Comparison of these values with those calculated from published data for aerobically growing organisms shows that the denitrifying consortium had lower detachment rate coefficients. This suggests that, similar to detachment rates in reactor-grown biofilms, detachment in porous media may increase with microbial growth rate. However, available literature data are not sufficient to confirm a specific analytical model for predicting this growth dependence.     

实用厨房油雾净化设备研制

针对厨房外排油雾气的实际情况，在调研国内外现有油雾净化设备的基础上，通过对过滤材料的实验研究，研制出新型的油雾滴过滤方法并开发出相应的设备。方法的关键在于滤料的布置方式。新的滤料布置方式在０３ｍ／ｓ的滤速时，效率高，保护作用时间长，阻力仅５００Ｐａ左右。实际运行的结果表明：该实用厨房油雾净化设备具有去油雾效果好、性能稳定、体积小、维护操作方便且无二次污染等特点。     

松散破碎岩石中气体渗流影响因素实验研究

由于储煤仓结构设计较为封闭,通风效果较差,导致煤仓内部残存瓦斯不能有效地排放,极易造成煤仓内瓦斯超限。通过对原煤仓内部空气渗流规律进行研究,可以对其进行合理地通风,从而有效地治理瓦斯超限问题。实验采用玻璃球体和碎石子作为填充介质,采用单一变量法研究了非均质各向同性多孔介质的渗流规律,以及非均质各向异性多孔介质的渗流规律。在此基础上得出,随着粒径和渗流速度的增加,渗透压力梯度也在增加;同时,随着粒径的增大,渗流状态由线性渗流转变为非线性渗流,渗流速度不断地减小,其渗流速度与压力梯度均呈现非线性变化规律。     

Convergence of stakeholders’ environmental threat perceptions following mass coral bleaching of the Great Barrier Reef

Managing human use of ecosystems in an era of rapid environmental change requires an understanding of diverse stakeholders’ behaviors and perceptions to enable effective prioritization of actions to mitigate multiple threats. Specifically, research examining how threat perceptions are shared or diverge among stakeholder groups and how these can evolve through time is increasingly important. We investigated environmental threat perceptions related to Australia's Great Barrier Reef and explored their associations before and after consecutive years of mass coral bleaching. We used data from surveys of commercial fishers, tourism operators, and coastal residents (n = 5254) conducted in 2013 and 2017. Threats perceived as most serious differed substantially among groups before bleaching but were strongly aligned after bleaching. Climate change became the most frequently reported threat by all stakeholder groups following the coral bleaching events, and perceptions of fishing and poor water quality as threats also ranked high. Within each of the 3 stakeholder groups, fishers, tourism operators, and coastal residents, the prioritization of these 3 threats tended to diverge in 2013, but convergence occurred after bleaching. These results indicate an emergence of areas of agreement both within and across stakeholder groups. Changes in perceptions were likely influenced by high-profile environmental-disturbance events and media representations of threats. Our results provide insights into the plasticity of environmental-threat perceptions and highlight how their convergence in response to major events may create new opportunities for strategic public engagement and increasing support for management.     

填料在净化污水过程中渗透性能变化趋势的研究

选取腐殖垃圾和砂以及两者质量比分别为4:1、3:2、2:3的混合物共5种填料,在1.0 m/d的水力负荷下,进行人工快速渗滤系统净化生活污水的试验,研究填料在进水过程中渗透性能的变化趋势.结果表明,腐殖垃圾的初始饱和水力渗透系数(K)最大,为3.32×10-2cm/s,而砂的初始K只有5.14×10-3cm/s,腐殖垃圾含量越大的混合物其仞始K也越大.在净化污水的过程中,5种填料的K逐渐减小,腐殖垃圾含量越大的混合物其K降幅也越大.随着进水时间的延长,各个填料柱填料层50～250 mm处的水头损失占总水头损失(填料层50～450mm处)的比例均逐渐增加,最终各个填料柱均发生堵塞,堵塞均发生在填料层50mm以上范围内.     

新型复合滤料过滤性能的实验研究及其应用

针对袋式除尘器滤料运行阻力过高问题 ,介绍了一种新型结构的复合滤料 (HBT)。对其过滤性能进行实验研究 ,结果表明在相同工况下 ,该滤料具有“高效低阻”特性 ,并在实际工程应用中取得了较好的效果。     

热轧浊循环水处理的中试研究

应用处理量8m3/h的压紧式改性纤维球压力过滤器,对某钢铁厂热轧浊循环水进行处理。结果表明,采用纤维球过滤能有效的去除热轧浊循环水中的油类和悬浮物(SS),过滤后的出水中油含量能降低到1.8~4.5mg/L,去除率达到84.5%,悬浮物(SS)最高9.5mg/L,平均5.04mg/L,去除率达到88.77%,满足该厂要求热轧循环用水油含量≤5mg/L,悬浮物≤10mg/L的要求。