淀粉-g-丙烯酸/凹凸棒土复合物制备及其吸附废水中NH_4~＋-N性能

采用反相乳液聚合法以凹凸棒土为原料,合成了新型NH4＋-N吸附剂淀粉-g-丙烯酸/凹凸棒土,并进行了氨氮吸附对比实验。结果表明：凹凸棒土氨氮单位吸附量为4.243 mg/g;淀粉-g-丙烯酸/凹凸棒土氨氮单位吸附量为5.301 mg/g,吸附能力比未改性的凹凸棒土提高了25%。淀粉-g-丙烯酸/凹凸棒土的氨氮吸附过程比凹凸棒土更符合Freundlich等温吸附模型。随着pH、温度的升高,凹凸棒土和淀粉-g-丙烯酸/凹凸棒土对NH4＋-N吸附量逐渐增大。     

钛基IrO2-SnO2电极在烟气海水脱硫恢复系统中的应用

采用浸渍-热分解法制备了含IrOx-TiO2中间层的IrO2-SnO2电极,得到的电极具有较高的析氯电催化活性和较强的稳定性,并通过电化学氧化法对Na2SO3海水脱硫模拟液进行处理,考察了电流密度、温度、pH值和电解时间等电解工艺参数对Na2SO3去除率和化学需氧量COD的影响.结果表明,在电流密度为200 mA/cm...     

壳聚糖的物理/化学改性及其对含酚废水的处理

将壳聚糖物理改性为球形颗粒,然后在微波辐射下,球形壳聚糖与柠檬醛接枝反应,再与NaBH4还原反应,制备一种新型环保材料--物化改性壳聚糖.采用红外光谱仪(IR)、X衍射仪(XRD)、电子显微镜(SEM)和比表面测定及孔径分析仪(BET)结构表征改性壳聚糖.通过含酚制药废水的动态小柱吸附实验,研究了时间、柱高和出水流速等...     

A2O工艺好氧末段溶解氧变化对脱氮除磷影响

采用连续流A2O工艺处理实际的生活污水,研究好氧末段在不同溶解氧(DO)浓度条件下对污泥沉降性能、系统脱氮除磷的影响,同时考察了DO对污泥硝化活性、厌氧释磷速率和反硝化脱氮速率的影响.结果表明,随着末段溶解氧的提高,污泥容积指数SVI从140降至100左右,后又升高到120～170;系统的硝化效果提高,氨氮的去除率从6...     

V/Ce共掺杂TiO2光催化降解甲醛的实验研究

采用溶胶凝胶法制备了不掺杂、V 掺杂、Ce掺杂、V/Ce共掺杂纳米TiO₂光催化剂,并将其分别负载于瓷砖上,利用X射线衍射分析（XRD）和扫描电镜分析（SEM）技术对薄膜样品的结构和形貌进行了表征。通过对甲醛的降解实验评价光催化剂的光催化活性。实验结果表明,光催化剂的负载量、共掺杂离子的掺杂量、掺杂配比、煅烧温度影响纳米TiO₂的光催化活性。V/Ce共掺杂TiO₂光催化剂产生了协同效应,其光催化活性优于纯TiO₂和单掺杂TiO₂样品。     

曝气强度对同时硝化反硝化（SND）脱氮过程中N2O排放的影响

为了控制污水脱氮中N2O排放,在不同曝气强度下研究了好氧硝化段同时硝化反硝化（SND）系统的N2O排放特性,并采用PCR—DGGE技术分析微生物群落特征。结果发现,随着曝气强度的增强,系统总氮去除率下降,但脱氮中N2O—N所占比例则上升,实验中从低到高3个曝气强度下,总氮去除率分别为80．01％、65．28％和58．62％,脱氮中N2O—N所占的比例为1．89％、7．84％和9．20％。PCR—DGGE分析显示,和低曝气强度下相比中、高曝气强度下系统微生物群落发生明显变化,但中曝气强度和高曝气强度下系统微生物群落表现出较高相似性。这表明,不同曝气强度下系统N2O排放受到氮素转化和微生物群落变化的影响。适宜曝气强度不仅提高总氮去除率,还可有效控制N2O排放。     

Spectral estimation of global levels of atmospheric pollutants

Underlying levels of atmospheric pollutants, assumed to be governed by smoothing mechanisms due to atmospheric dispersion, can be estimated from global emissions source databases on greenhouse gases and ozone-depleting compounds. However, spatial data may be contaminated with noise or even missing or zero-valued at many locations. Therefore, a problem that arises is how to extract the underlying smooth levels. This paper sets out a structural spatial model that assumes data evolve across a global grid constrained by second-order smoothing restrictions. The frequency-domain approach is particularly suitable for global datasets, reduces the computational burden associated with two-dimensional models and avoids cumbersome zero-inflated skewed distributions. Confidence intervals of the underlying levels are also obtained. An application to the estimation of global levels of atmospheric pollutants from anthropogenic emissions illustrates the technique which may also be useful in the analysis of other environmental datasets of similar characteristics.     

Regulation (EC) No. 1107/2009 and upcoming challenges for exposure assessment of plant protection products--Harmonisation or national modelling approaches?

In the new European Pesticide Regulation (EC) No. 1107/2009, the harmonisation of approaches for estimation of the environmental exposure of pesticides is considered a major goal. Several member states currently require their own models for the calculation of predicted environmental concentrations (PEC) in surface water. The variety of methods makes risk evaluations rather time-consuming for both notifiers and evaluating authorities. In the present study we compare surface water concentrations of 19 compounds using EU and country-specific models and risk assessment approaches to evaluate to which extent the resulting estimated exposure concentrations differ. Our results show that EU and country specific approaches and the resulting surface water concentrations differ considerably regarding basic model assumptions and assessment methods. The results indicate that the aimed harmonisation of risk assessment approaches within the EU will be difficult based on current models. New scenarios may help to achieve a harmonisation taking country-specific features into account.     

焦化行业SO2排放现状及减排潜力分析

随着钢铁工业的高速发展,高温炼焦已成为中国煤炭资源利用的重要途径之一,与此同时焦化行业SO2排放污染问题越来越引起人们的关注.2007年,全国焦炭产量总计335.53 Mt,其中机械化焦炉产量达305.37 Mt,约占全国焦炭产量的91.01%,焦化行业SO2排放量达181.19 kt.在参考国家制定的焦化行业未来产业...     

季铵化合物对好氧活性污泥吸附Ni2+的影响研究

以季铵化合物中最具潜在影响力、毒性较大的苄基季铵盐(BAC)为模型物,进行了BAC对好氧活性污泥吸附Ni2+的影响研究.结果表明,当反应液初始pH≤3时,不同浓度的BAC对好氧活性污泥吸附Ni2+的影响较小,当初始pH在3～9时,不同浓度的BAC对Ni2+吸附的抑制影响顺序为100 mg/L＞20 mg/L＞0 mg/...