进水水质成分改变引发的污泥粘性膨胀及控制

在研究强化SBR工艺除污性能时,由于可溶性淀粉投加导致进水水质成分发生改变,污泥沉降性能在短时间内迅速恶化,污泥出现大量的粘液。镜检发现,大量指状菌胶团异常增殖且丝状菌的数量也逐渐减少。实验结果表明,系统膨胀属于污泥粘性膨胀。停止可溶性淀粉和提高主反应池的DO浓度,污泥粘性膨胀并未得到恢复,但污泥粘液逐渐消失。粘液消失后,通过模拟前期进水水质成分和缩短泥龄,污泥粘性膨胀得以控制,污泥沉降性能在短时间内恢复。实验还研究了污泥粘性膨胀对污染物去除性能的影响。     

Development of Lignin and Nanocellulose Enhanced Bio PU Foams for Automotive Parts

The green rigid polyurethane (PU) foam has been developed with 100 % soy polyol after optimization of formulation ingredients and lignin has been introduced and isocyanate content reduced in the green rigid PU foam. The cellulosic nanofibers have also been successfully incorporated and dispersed in green rigid PU foam to improve the rigidity. The influence of nano cellulose fiber modification (enzymatic treatment, hydrophobic modification with latex) on the foam density, open cell content, foam raise height, water vapor, and mechanical properties of rigid PU foam were studied. The foamed structures were examined using scanning electron microscopy to determine the cell size and shape due to the addition of cellulosic nanofibers. The odor test were performed to evaluate the odor concentration 100 % soyol based PU foam including lignin and nanofiber and compared to 100 % synthetic based polyol PU foam. The experimental results indicated that the compression and impact properties improved due to the modification of nano cellulosic fibers. The odor concentration level of nanofiber reinforced rigid PU foam reduced significantly compared to 100 % PU foam due to the replacing of isocyanate content. It can be said that with an appropriate combination of replacing isocyanate by lignin and addition of nanofiber, rigid PU foam properties could be improved.     

As（V）在金红石TiO2颗粒表面吸附特性及机理

通过静态动力学和热力学吸附实验,研究了温度、共存离子以及溶质的初始浓度对As（V）在金红石TiO2颗粒表面吸附的影响,探讨了As（V）在金红石TiO2颗粒表面吸附特性及机理。结果表明,在As（V）初始浓度为10mg／L,pH为7的条件下,25℃时的吸附量0．41mg／g高于30℃时的吸附量0．31mg／g,As（V）在金红石TiO,上的吸附为放热过程。CaCl2和MgCl2的添加对As（V）在金红石TiO2表面吸附起到明显的促进作用。T=25℃,Ca2＋或Mg2＋浓度为10mmol／L时,As（V）吸附量分别为0．64和0．56mg／g,Ca2＋比Mg2＋对As（V）吸附促进作用强。As（V）在金红石TiO2的吸附等温线符合Frendlich方程,Lagergren二级动力学方程能较好地描述As（V）在金红石TiO2颗粒表面吸附的动力学过程。     

交联壳聚糖/沸石复合吸附剂的制备及性能

用沸石负载由缩水甘油基三乙基氯化铵交联的壳聚糖,制得了性能良好的交联壳聚糖/沸石复合吸附剂。研究了该吸附剂应用性能的影响因素,探讨了该吸附剂的吸附性、沉降性和重复使用性,利用FTIR仪和高倍透射电子显微镜对该吸附剂的结构进行了表征。实验结果表明:壳聚糖的交联度为0.93、交联壳聚糖与沸石的质量比为0.045时,制得的交联壳聚糖/沸石复合吸附剂对腐殖酸的去除率可达81.4%,吸附量为4.07mg/g;交联壳聚糖/沸石复合吸附剂对腐殖酸的吸附性能较沸石有显著提高,沉降时间较交联壳聚糖明显缩短;经二次洗脱后腐殖酸去除率仍可达80.2%,腐殖酸吸附量为4.01mg/g。     

Occurrence, distribution, and sources of six phenolic endocrine disrupting chemicals in the 22 river estuaries around Dianchi Lake in China

The objectives of this study are to track the occurrence, distribution, and sources of phenolic endocrine disrupting compounds (EDCs) in the 22 rivers around Dianchi Lake in China, to estimate the input and output amounts of phenolic EDCs in the water system, and to provide more comprehensive fundamental data for risk assessment and contamination control of phenolic EDCs in aquatic environment. Six phenolic EDCs were systematically evaluated in water and surface sediment in the estuaries of those rivers. The water and sediment samples were preconcentrated by solid-phase extraction system and microwave-assisted extraction system, respectively. Phenolic EDCs were analyzed by GC-MS (Thermo Fisher Scientific, USA) after derivatization. Phenolic EDCs were found ubiquitously in the aquatic environment. The total concentrations ranged from 248 to 4,650 ng/L in water, and 113 to 3,576 ng/g dry weight in surface sediment. The residue amount of phenolic EDCs in Dianchi Lake was 258 kg/a. Concentrations of the phenolic EDCs in the Lake decreased with increase in distance to the estuaries of those rivers which run through urban and industrial areas. The rivers seriously contaminated by phenolic EDCs were Xin River, Yunliang River, Chuanfang River, Cailian River, Jinjia River, Zhengda River, and Daqing River which run through the old area of Kunming City. Satisfying correlations were observed between the concentrations of the target compounds in water and in surface sediment. NP1EO, NP2EO, and BPA were identified as the three predominant phenolic EDCs. There were significant correlations between phenolic EDCs and many basic water quality parameters. Urban and industrial areas are the major contributors for phenolic EDCs, especially in Kunming City. Compositional profiles of phenolic EDCs in surface sediment were similar to those in river water. The concentrations of phenolic EDCs in the rivers located in the northwest part of the valley were very high, and posed a potential risk to aquatic organisms and even human. The concentrations of NP2EO, NP1EO, and BPA were at moderate levels of other areas. The basic water quality parameters (TOC, TN, DO, and pH) play important roles on the distribution, fate, and behavior of phenolic EDCs in the valley.     

The acute effects of fine particles on respiratory mortality and morbidity in Beijing, 2004–2009

Recent epidemiological and toxicological studies have shown associations between particulate matter and human health. However, the estimates of adverse health effects are inconsistent across many countries and areas. The stratification and interaction models were employed within the context of the generalized additive Poisson regression equation to examine the acute effects of fine particles on respiratory health and to explore the possible joint modification of temperature, humidity, and season in Beijing, China, for the period 2004–2009. The results revealed that the respiratory health damage threshold of the PM_2.5 concentration was mainly within the range of 20–60 μg/m³, and the adverse effect of excessively high PM_2.5 concentration maintained a stable level. In the most serious case, an increase of 10 μg/m³ PM_2.5 results in an elevation of 4.60 % (95 % CI 3.84–4.60 %) and 4.48 % (95 % CI 3.53–5.41 %) with a lag of 3 days, values far higher than the average level of 0.69 % (95 % CI 0.54–0.85 %) and 1.32 % (95 % CI 1.02–1.61 %) for respiratory mortality and morbidity, respectively. There were strong seasonal patterns of adverse effects with the seasonal variation of temperature and humidity. The growth rates of respiratory mortality and morbidity were highest in winter. And, they increased 1.4 and 1.8 times in winter, greater than in the full year as PM_2.5 increased 10 μg/m³.     

Occurrence and distribution of heavy metals and tetracyclines in agricultural soils after typical land use change in east China

Land use in east China tends to change from paddy rice to vegetables or other high-value cash crops, resulting in high input rates of organic manures and increased risk of contamination with both heavy metals (HMs) and antibiotics. This investigation was conducted to determine the accumulation, distribution and risks of HMs and tetracyclines (TCs) in surface soils and profiles receiving different amounts of farmyard manure. Soil samples collected from suburbs of Hangzhou city, Zhejiang province were introduced to represent three types of land use change from paddy rice to asparagus production, vineyards and field mustard cultivation, and divided into two portions, one of which was air-dried and sieved through 2-, 0.3- and 0.149-mm nylon mesh for determination of pH and heavy metals. The other portion was frozen at ?20 °C, freeze-dried and sieved through a 0.3-mm nylon mesh for tetracyline determination. HM and TC concentrations in surface soils of 14-year-old mustard fields were the highest with total Cu, Zn, Cd and ∑TCs of 50.5, 196, 1.03 mg?kg^?1 and 22.9 μg?kg^?1, respectively, on average. The total Cu sequence was field mustard?>?vineyards?>?asparagus when duration of land use change was considered; oxytetracycline (OTC) and doxycycline were dominant in soils used for asparagus production; OTC was dominant in vineyards and chlortetracycline (CTC) was dominant in mustard soils. There were positive pollution relationships among Cu, Zn and ∑TCs, especially between Cu and Zn or Cu and ∑TCs. Repeated and excessive application of manures from intensive farming systems may produce combined contamination with HMs and TCs which were found in the top 20 cm of the arable soil profiles and also extended to 20–40 cm depth. Increasing manure application rate and cultivation time led to continuing increases in residue concentrations and movement down the soil profile.     

Effect of silicate supplementation on the alleviation of arsenite toxicity in 93-11 (Oryza sativa L. indica)

Chronic exposure to arsenic (As) in rice has raised many health and environmental problems. As reported, great variation exists among different rice genotypes in As uptake, translocation, and accumulation. Under hydroponic culture, we find that the Chinese wild rice (Oryza rufipogon; acc. 104624) takes up the most arsenic among tested genotypes. Of the cultivated rice, the indica cv. 93-11 has the lowest arsenic translocation factor value but accumulates the maximum concentration of arsenic followed by Nipponbare, Minghui 86, and Zhonghua 11. Higher level of arsenite concentration (50 μM) can induce extensive photosynthesis and root growth inhibition, and cause severe oxidative stress. Interestingly, external silicate (Si) supplementation has significantly increased the net photosynthetic rate, and promoted root elongation, as well as strongly ameliorated the oxidative stress by increasing the activities of antioxidant enzymes superoxide dismutase, ascorbate peroxidase, and peroxidase in roots and/or leaves of 93-11 seedlings. Notably, 1.873 mM concentration of Si considerably decreases the total As uptake and As content in roots, but significantly increases the As translocation from roots to shoots. In contrast, Si supplementation with 1.0 mM concentration significantly increases the total As uptake and As concentrations in roots and shoots of 93-11 seedlings after 50 μM arsenite treatment for 6 days.     

青岛市餐厨垃圾现状调查及分析

通过问卷与实地跟踪形式调查青岛市4个主城区餐厨垃圾现状并提出关于餐厨垃圾管理和处置的建议,力求为该市餐厨垃圾的资源化利用提供参考.调查结果显示:餐厨垃圾产量为265.00 t/d,含水率为74.93％、含油率为6.06％、营养物为12.22％(质量分数);54.4％的调查餐饮单位将餐厨垃圾分为剩饭菜、废油和生活垃圾3类排放,需进一步加强餐厨垃圾分类放置的管理工作;所调查餐饮单位中有64.4％的剩饭菜、54.3％的废油由政府统一收运,统一收运率有待进一步提高;正规回收的餐厨垃圾为197.66 t/d,被用于堆肥或进行填埋处置.     

木屑处置漏油事故的室内模拟

用锯木屑作为吸附材料,0#柴油为吸附对象进行室内模拟实验,研究了木屑对纯油、水中浮油的吸附以及吸油后的木屑在水中的漂浮性能;并以木屑粒径、木屑投加量、振荡频率、油膜厚度为研究指标,设计了5因素4水平的正交实验,考察了各因素对0#柴油的吸附量、去除率以及木屑漂浮率的影响并对优化条件进行了讨论。结果表明,在实验研究范围内,木屑对水中柴油的吸附速度极快,1min即可达到饱和,饱和吸附量为8．08g／g;木屑在水中漂浮性能良好,静态时经72h漂浮,漂浮率维持在92％左右;振荡频率为150r／min时,72h内漂浮率维持在68％以上;最佳吸油条件组合为吸附剂粒径10～20目,振荡频率120r／min,木屑投加量0．7g,油膜厚度1．65mm。