微波活化过硫酸钾深度处理印染废水

为了深度处理印染废水生化出水,使其达到工业回用要求,利用微波活化过硫酸钾产生具有强氧化性的硫酸根自由基·SO-4,降解印染废水生化出水中的有机污染物。考察了硫酸亚铁的投加量,过硫酸钾的浓度及pH的影响,并通过对比实验讨论了微波活化作用效果。结果表明,过硫酸钾微波组合能够有效地去除生化出水中的TOC和色度。对于某印染废水生化出水,处理效果在pH=10时最好,当过硫酸钾浓度为14 g/L时,TOC去除率达57.60%,脱色率为98.28%。研究结果表明,过硫酸钾微波组合对于印染废水的深度处理效果良好,有较好的应用前景。     

5种植物材料的水解释碳性能及反硝化效率

碳源在硝酸盐去除过程中起电子供体的作用,是生物反硝化反应的关键物质之一。为解决污水处理脱氮时碳源不足抑制反硝化反应造成脱氮效率低的问题,本研究选取风车草、甘蔗渣、芦竹、美人蕉和稻草秆5种植物材料作为反硝化碳源,探讨不同植物材料的水解释碳能力和释放规律;并进一步以其水解液作为外加碳源,探讨其对反硝化脱氮效率的影响。研究结果表明,植物材料水解释碳过程符合二级动力学反应规律,不同植物材料的释碳能力具有显著性差异,以甘蔗渣在固液比1∶80时COD释放当量最大,为45.45 mg/L;添加植物水解液可显著提高反硝化脱氮效率,以芦竹水解液脱氮效果最好,达到71.9%。此外,碳氮比是影响脱氮效率的重要因素之一,以碳氮比为9时反硝化脱氮效果最佳。     

Enhanced degradation of ortho-nitrochlorobenzene by the combined system of zero-valent iron reduction and persulfate oxidation in soils

ortho-Nitrochlorobenzene (o-NCB) in soil poses significant health risks to human because of its persistence and high toxicity. The removal of o-NCB by both zero-valent iron (ZVI) and chemical oxidation (persulfate) was investigated by batch experiments. The o-NCB removal rate increases significantly from 15.1 to 97.3 % with an increase of iron dosage from 0.1 to 1.0 mmol g^?1. The o-NCB removal rate increases with the decrease of the initial solution pH, and a removal efficiency of 90.3 % is obtained at an initial pH value of 6.8 in this combined system. It is found that temperature and soil moisture could also increase the o-NCB removal rate. The o-NCB degradation rate increases from 83.9 to 96.2 % and from 41.5 to 82.4 % with an increase of temperature (15 to 35 °C) and soil moisture (0.25 to 1.50 mL g^?1), respectively. Compared to the persulfate oxidation system and ZVI system, the persulfate–iron system shows high o-NCB removal capacity. o-NCB removal rates of 41.5 and 62.4 % are obtained in both the persulfate oxidation system and the ZVI system, while the removal rate of o-NCB is 90.3 % in the persulfate–iron system.     

Effects of cadmium on the photosynthetic activity in mature and young leaves of soybean plants

Cadmium (Cd) is a widely spread pollutant and can be easily taken up by crop from soil, resulting in a serious health issue for humans. The objective of this study was to comparatively investigate the photosynthetic activity, chlorophyll a fluorescence, chlorophyll contents, and spectral reflectance in mature and young leaves of soybean plants after being treated with different concentrations of Cd for 10 days. The photosynthetic rate, chlorophyll contents, actual photochemical efficiency of PSII, and photochemical quenching in the young leaves decreased more significantly with increasing concentrations of Cd in the nutrient solution, compared with those in the mature leaves, though the young leaves had less Cd concentrations. Thus, there was more excessive excited energy produced in the young leaves than that in the mature leaves. In the young leaves, due to more excessive excited energy, more reactive oxygen species may be generated, which further damaged the photosynthetic apparatus. It was supported by the fact that the decrease of reflectance in near-infrared wavelengths of the young leaves was more noticeable than that of the mature leaves. In addition, the chlorophyll a fluorescence transients of the young leaves was significantly different from that in the mature leaves, indicating that the electron transport of young leaves were inhibited much more severely than that of the mature leaves. These observations imply that the responses of photosynthetic activity of soybean leaves to Cd stress depend on their growth stage, and the Cd-induced inhibition of photosynthetic activity might be attributed to the decrease in chlorophyll contents and the decrease in mesophyll CO₂ assimilation ability cause by the Cd, which further decreased the consumption of ATP and NADPH, leading to accumulation of NADPH on the acceptor sides of the PSI, and then feedback inhibited electron transport in chloroplasts.     

活性炭纤维负载TiO2催化剂的制备及其电催化性能

采用溶胶-凝胶法制备了活性炭纤维负载TiO₂催化剂（TiO₂/ACF）,并通过SEM和XRD等手段对TiO₂/ACF进行了表征。以邻苯二甲酸二甲酯（DMP）为目标降解物,考察了催化材料的电催化活性。实验结果表明：在反应温度为25 ℃、初始DMP质量浓度为100.0 mg/L、电解质Na₂SO₄质量浓度为100 mg/L、电流密度为62.5 mA/cm²、电极板间距为4 cm的条件下,经过40 min的降解,DMP质量浓度为1.8 mg/L,DMP去除率为98.2%;TiO₂/ACF在反应过程中可以原位再生,经6次重复使用后仍保持很高的催化活性,对DMP的去除率仍达90%以上。     

反应气耦合等离子体降解沙林模拟剂

采用水蒸气、氨气、过氧化氢气雾和臭氧4种气体对沙林模拟剂氟磷酸二异丙酯(DFP)进行降解研究,发现臭氧对DFP具有较好的降解作用,在流量200 L/h,DFP初始浓度50 mg/m3时,降解率最高可达56.1%。对高浓度DFP(大于80 mg/m3)进行降解研究时,等离子体单独作用最高降解率为89%,而添加臭氧后的降解率都在95%以上。计算得到臭氧作用的能量利用率为0.05 mg/(W·h),等离子体的能量利用率为0.55 mg/(W·h),而添加臭氧后的等离子体能量利用率为0.68 mg/(W·h)明显高于臭氧和等离子体能量利用率之和,因此对高浓度DFP进行处理时,臭氧与等离子体存在耦合作用。对等离子体和臭氧耦合等离子体降解DFP反应进行了产物分析,发现主要的降解产物基本一致,但是臭氧的存在能使降解更加彻底。     

电渗透脱水对污泥热干燥特性的影响

以污水厂机械脱水后的污泥作为研究对象,提出了采用电渗透-热干燥结合进行深度脱水的方法。通过对原泥以及电渗透脱水至不同含水率(67%、71%和76%)的污泥在热干燥过程中含水率和干燥速率的测定,分析电渗透脱水对污泥热干燥特性的改善规律。结果表明,经电渗透脱水至含水率为67%和71%的污泥在热干燥过程中的传热传质速率及干燥速率有明显提高,且干燥温度越高,电渗透后污泥的干燥速率与原泥的干燥速率差距越大。相同电压梯度及相同温度下电渗透至67%后进行热干燥耗能最少。实际应用中应结合能耗分析选择合适的电渗透程度及干燥温度,以达到最优效果。     

Simazine biodegradation and community structures of ammonia-oxidizing microorganisms in bioaugmented soil: impact of ammonia and nitrate nitrogen sources

The objective of the present study was to investigate the impact of ammonia and nitrate nitrogen sources on simazine biodegradation by Arthrobacter sp. strain SD1 and the community structures of ammonia-oxidizing archaea (AOA) and bacteria (AOB) in non-agricultural soil. Soil microcosms with different treatments were constructed for herbicide biodegradation test. The relative abundance of the strain SD1 and the structures of AOA and AOB communities were assessed using quantitative PCR (q-PCR) and terminal restriction fragment length polymorphism (TRFLP), respectively. The co-existence of two inorganic nitrogen sources (ammonia and nitrate) had certain impact on simazine dissipation by the strain SD1. Bioaugmentation could induce a shift in the community structures of both AOA and AOB, but AOA were more responsive. Nitrogen application had significant impacts on AOA and AOB communities in bioaugmented soils. Moreover, in non-bioaugmented soil, the community structure of AOA, instead of AOB, could be quickly recovered after herbicide application. This study could add some new insights towards the impacts of nitrogen sources on s-triazine bioremediation and ammonia-oxidizing microorganisms in soil ecosystem.     

降解SO2功能菌的16S rRAN基因测序及降解特性

用低浓度SO2诱导驯化方法获得高效脱硫菌群,并用分离培养与16S rRNA基因测序技术相结合的方法鉴定菌群种属,分析驯化过程中种群结构的动态变化,同时研究分离纯菌种的脱硫性能。结果表明,从诱导驯化7 d和14 d菌液中分别分离出23株菌和22株菌,16S rRNA序列分析发现这些菌归属于13个种,其中有6个种(Rhodococcus erythropolis、Pseudomonas putida、Microbacterium oxydans、Sphingomonas koreensis、Acinetobacter junii、Acinetobacter johnsonii)对SO2-3有较强的降解能力,并在持续驯化过程中稳定的生长传代,降解产物以硫酸根为主,还有极少量的单质硫。与含混合菌的驯化菌液降解SO2-3的能力相比,单一脱硫菌的脱硫性能较弱。脱硫功能菌株及其基本特性的研究为微生物处理SO2烟气提供了丰富的菌源信息和理论基础。     

集中排烟公路隧道入口段火灾下诱导风速研究

为研究集中排烟模式下公路隧道入口段发生火灾时的合理诱导风速,以某公路隧道为背景,运用火灾动力学模拟软件FDS对隧道人口段火灾时不同坡度、不同诱导风速的16组火灾工况进行模拟研究,通过对各工况下隧道内的温度场分布及烟气控制效果模拟结果的分析,得到了各工况下的合理诱导风速,研究结果可为公路隧道集中排烟系统关键设计参数提供参考.