MBR污水处理工艺中活性污泥动力学参数测定

缺乏可靠的污泥动力学设计参数是膜-生物反应器（membrane bioreactor,MBR）工艺在实际应用中遇到的主要问题之一.以某座处理城市污水的实际规模MBR工程的好氧活性污泥为对象,采用耗氧速率表征方法,测定计算得到以下动力学参数值：异养菌产率系数Y_H＝0.693、自养菌产率系数Y_A＝0.263、异养菌衰减系数K_dH＝0.108 d^-1、自养菌衰减系数K_dA＝0.089 d^-1、COD最大比去除速率v_mS＝1.94 mg·(mg·d)^-1、COD去除半饱和常数K_S＝34.6 mg·L^-1、氨氮最大比去除速率v_mN＝0.18 mg·(mg·d)^-1、氨氮去除半饱和常数K_N＝1.06 mg·L^-1.以上结果与传统活性污泥法工艺（CAS）中污泥的文献报道值相比,Y_H和K_dH较高,而v_mS和v_mN较低.MBR的高污泥浓度条件可能是导致上述差异出现的主要原因.     

土壤中砷的形态及生物有效性研究

土壤中砷的可移动性主要取决于其存在形态,并决定了其生物有效性,生物对不同形态砷的吸收利用程度亦不同,本文阐述了土壤中砷的形态及生物吸收的研究进展,总结了砷的生物有效性研究概况,对影响砷生物有效性的主要因素展开分析.其不仅与重金属本身的化学形态和结合相态有关,还受主壤化学性质及土壤环境中的物理、化学及生物作用影响,砷的生...     

Kinetics of Solvent Blue and Reactive Yellow removal using microwave radiation in combination with nanoscale zero-valent iron

We investigated the efficiency and kinetics of the degradation of soluble dyes over the p H range 5.0–9.0 using a method employing microwave radiation in combination with nanoscale zero-valent iron(MW–n ZVI). The n ZVI particles(40–70 nm in diameter) were prepared by a liquid-phase chemical reduction method employing starch as a dispersant.Compared to the removal of Solvent Blue 36 and Reactive Yellow K-RN using only n ZVI,more rapid and efficient dye removal and total organic carbon removal were achieved using MW–n ZVI. The dye removal efficiency increased significantly with decreasing p H, but was negligibly affected by variation in the microwave power. The kinetics of dye removal by MW–n ZVI followed both an empirical equation and the pseudo first-order model, while the kinetics of dye removal using n ZVI could only be described by an empirical equation. It was also concluded that microwave heating of the dye solutions as well as acceleration of corrosion of n ZVI and consumption of Fe(II) were possible reasons behind the enhanced dye degradation.     

Development and demonstration of fuel cell vehicles and supporting infrastructure in China

The demand for urban transportation in China, including cars, motorbikes, buses, and trains, is growing substantially. China’s transportation fleet is projected to expand from 16 to 94 million vehicles between 2000 and 2020, with liquid and electricity transport fuel demand growing from about 5 Quadrillion British Thermal Units (Quads) to over 20 Quads in 2035. In response to energy security, economic growth and environmental protection needs, Chinese government agencies, academia and the private sector have organized their programs and investments to advance development and demonstration of sustainable alternative transportation systems. This analysis surveys historic development of fuel cell vehicle (FCV) including fuel cell buses (FCB) technology in China, summarizes recent efforts to scale-up FCV development and associated infrastructure in major Chinese cities, and briefly addresses future directions in Chinese fuel cell and hydrogen energy technology development. Since the late 1990’s, Chinese universities, government institutions and the private sector have implemented research, development, demonstration and deployment programs for electric (EV), fuel cell (FCV), and hybrid electric vehicles (HEV). These efforts have advanced the feasibility of FCVs to be a part of sustainable urban transportation system, including technical performance, infrastructure, and customer acceptance. Three generations of FCVs, START I, START II and START III have been developed, demonstrated and deployed. Similarly, several generations of FCBs have been developed and demonstrated. Collectively, these efforts have demonstrated and deployed over 1,000 FCBs and FCVs in several Chinese cities. Large-scale, intensive-use FCV and FCB demonstration trials, including those during the 2008 Beijing Olympics and the 2010 Shanghai World Exposition (EXPO), have been successfully built and operated. Infrastructure, such as hydrogen production facilities, fuelling stations, and maintenance stations have been constructed and operated to support the fleets of FCBs and FCVs. Experiences learned from these FCV research, development, and demonstration activities are the foundation for scaling up infrastructure and fleet trials in a growing number of cities in eastern and western China. An aggressive research and development vision and 2020 technology performance targets provide a foundation for the next generation of EVs, FCVs and HEVs, and, options for China’s efforts to develop a portfolio of sustainable transportation systems.     

VUV/HPW/BMMs体系对全氟辛酸（PFOA）的脱氟研究

采用真空紫外灯(VUV)和双模型介孔材料(BMMs)负载磷钨酸(HPW)催化剂构建光催化体系,探究该体系对水中全氟辛酸(PFOA)的脱氟效果.研究了PFOA初始浓度、HPW/BMMs投加量、初始p H值对体系脱氟的影响,并采用响应曲面法(Response Surface Method,RSM)分析了最佳边界反应条件.结果表明,体系对PFOA具有明显的脱氟效果:脱氟效率随PFOA初始浓度的增大而减小;催化剂投加量为0.2 g·L~(-1),脱氟效率最高达50.2%;体系p H为3~4时,体系脱氟效果显著.基于Box-Behnken响应曲面法,各影响因子对脱氟效率的显著性排序为:p HPFOA初始浓度HPW/BMMs投加量.p H值与HPW/BMMs投加量及初始PFOA浓度交互作用显著,模型回归性良好,最佳运行条件为:p H=3.82,HPW/BMMs投加量为0.3 g·L~(-1),PFOA初始浓度为20 mg·L~(-1),反应4 h的脱氟率达到52.6%,与预测值相比偏差为1.2%.本研究为高效降解全氟化合物提供了新思路.     

深圳市一次典型污染天气污染特征分析研究——以2016年3月空气质量为例

2016年3月31日,深圳市及其周边地区出现典型的区域性空气污染事件,多数地区的AQI超过了100.主要污染物浓度和气象要素的逐小时变化表明,该次污染天气主要是在不利气象条件下,由污染物区域传输和二次污染物生成共同导致的.进一步的后向轨迹分析表明,污染日抵达深圳市的气团可能从东莞、广州和佛山等地区携带了大量污染物,并且移动速度缓慢,造成了深圳较为严重的污染天气,而污染日前和污染日后抵达深圳市的气团有利于污染物的稀释扩散,因此空气质量较好.     

常绿阔叶林改造为板栗林对土壤氮磷钾库及酶活性的影响

研究天然林改造为人工林对土壤养分库的影响,对于森林的可持续经营具有非常重要的意义。论文为探明天然常绿阔叶林改造为板栗林对土壤氮磷钾库及酶活性的影响,在浙江省临安市三口镇采集了相邻的天然常绿阔叶林和板栗林（板栗林由天然常绿阔叶林改造而来）的表层（0~20 cm）与亚表层（20~40 cm）土壤,测定土壤不同形态氮磷钾素和蔗糖酶、脲酶、过氧化氢酶和酸性磷酸酶的活性。结果表明：表层和亚表层土壤pH值、水溶性有机氮（WSON）和微生物量氮（MBN）均显著降低,而铵态氮和硝态氮含量均显著增加（P < 0.05）;表层土壤全氮含量显著增加,而亚表层土壤全氮含量无显著变化;表层土壤树脂提取态磷（Resin-P_i）、碳酸氢钠提取态无机磷（NaHCO₃-P_i）、氢氧化钠提取态无机磷（NaOH-P_i）、盐酸提取态磷（HCl-P_i）和残余态磷（Residual-P）含量分别增加了61.4%、53.5%、19.2%、55.1%和25.3%,亚表层土壤Resin-P_i、NaHCO₃-P_i、HCl-P_i和Residual-P含量分别增加了64.6%、61.2%、13.7%和17.3%;而表层土壤碳酸氢钠提取态有机磷（NaHCO₃-P_o）和氢氧化钠提取态有机磷（NaOH-P_o）含量分别下降了24.8%和18.3%,亚表层土壤NaHCO₃-P_o和NaOH-P_o含量分别下降了20.5%和7.7%;表层土壤的速效钾、缓效钾、矿物态钾和全钾含量均显著增加,亚表层土壤速效钾、缓效钾含量显著增加,而矿物态钾和全钾无显著变化;表层土壤蔗糖酶、脲酶、过氧化氢酶和酸性磷酸酶活性显著下降,亚表层土壤脲酶和酸性磷酸酶活性显著下降（P < 0.05）。综上,上述林分转变对土壤无机氮磷钾库具有正面效应,而对土壤有机氮磷钾库与酶活性具有负面效应。     

Cadmium accumulation and tolerance of two castor cultivars in relation to antioxidant systems

To investigate the effects of Cd on tolerance and antioxidant activities of castor, two different castor（Ricinus communis L.） cultivars（Zibo No. 5 and Zibo No. 8） were used for a hydroponic experiment（0, 1 and 2 mg/L Cd） and a pot experiment using Cd-contaminated soil（34 mg/kg） with the addition of ethylenedinitrilotetraacetic acid（EDTA）. The results indicated that there were significant differences between the two cultivars with respect to Cd uptake in shoots（113–248 mg/kg for Zibo No. 5 and 130–288 mg/kg Zibo No. 8）, biomass tolerance indexes（64.9%–74.6% for Zibo No. 5 and 80.1%–90.9% for Zibo No. 8） in the hydroponic experiment and survival rates（0% for Zibo No. 5 and 100% for Zibo No. 8）determined by the addition of EDTA in the pot experiment, suggesting that Zibo No. 8 has higher tolerance than Zibo No. 5. Moreover, the castor cultivars have low bioconcentration factors（4.80% for Zibo No. 5 and 5.43% for Zibo No. 8） and low translocation factors（〈1%）.Consequently, Zibo No. 8 can participate in Cd phytostabilization in highly Cd-polluted areas. The results indicated that glutathione（GSH） as a non-enzymatic antioxidant, and antioxidant enzymes including superoxide dismutase（SOD）, catalase（CAT） and guaiacol peroxidase（GPX）, were cultivar- and dose-dependent. The higher tolerance of Zibo No. 8compared with Zibo No. 5 can be attributed to the higher GSH levels in the root and higher GPX activity in the leaf.     

滇池沉积物中多氯联苯和有机氯农药的残留特征与风险评估

从滇池不同区域采集到11个表层沉积物,测定2类持久性有机污染物即多氯联苯(PCBs)和有机氯农药(OCPs)的含量,同时对沉积物中污染物的污染程度、分布特征、污染来源进行了研究。结果表明,沉积物中污染残留总体含量为DDTsHCHsPCBs,含量分别是0.26~75.20ng/g,0.63~26.0ng/g和0.64~17.7ng/g;污染物分布受人工大坝阻隔作用明显,大坝上游沉积物中污染物含量比下游高一到二个数量级。PCBs组成以三氯和五氯为主,这与我国历史上多氯联苯产品的生产和使用状况相吻合。(p,p'-DDE+p,p'-DDD)/DDTs0.84和β-HCH/HCHs0.45,比值结果显示出OCPs组成以降解和残留产物为主,表明周边土壤中残留的农药是滇池沉积物中农药的主要来源。生态风险值采用加拿大环保局提出的生态风险评价框架,结果表明,滇池上游(草海)沉积物总体潜在风险较高,应当引起关注。     

预氧化加复合絮凝剂处理高温石油废水

采用自制ＰＣＭ２复合药剂处理含油和高分散细微悬浮物石油废水。研究证明，使用现有单一的有机或无机絮凝剂无法达到对这种具有特殊水质的石油废水的期望处理效果。在被处理水为室温的条件下，适量的ＰＣＭ２不仅有效去除水中的油，而且可以将难处理的细微悬浮物含量降到较低。在高温处理条件下，采取预氧化加ＰＣＭ２可以显著提高对水中油尤其是细微悬浮物的去除效率，处理后水质可以达到油田回注标准。