废弃中药渣催化热解制取生物油的研究

利用热重分析仪(TGA)对植物类中药渣的热解特性进行了研究,用Coats-Redfern积分法计算了其热解动力学参数,得出中药渣热解反应符合一级反应动力学方程,其活化能较低,为36.0kJ/mol。考察了热解温度对气体、液体、固体产物的影响,在723K时,液体产物生物油产率最高,为39%。以介孔分子筛SBA-15以及分别负载Al、Sn、Ni、Cu和Mg的SBA-15作为催化剂,研究催化热解对气体、液体、固体产率及生物油组分的影响。研究表明,Al-SBA-15的催化效果较好,液体产率最高,为36%;采用元素分析仪和热值测定仪,得到用Al-SBA-15作为催化剂时生物油的氧质量分数最低,低位热值最高。用GC/MS对生物油组分的分析结果表明,添加Al-SBA-15后,热解产物中脂肪族和芳香族化合物增加,而含氧化合物减少。     

湿法净化黑烟中添加剂对炭黑沉降性能的影响

湿法净化黑烟中炭黑颗粒物的关键在于降低吸收液的表面张力并以高性能絮凝剂使其从溶液中絮凝、沉降以利于分离。选用十六烷基三甲基溴化胺(CTAB)为主要表面活性剂,使之与十二烷基苯磺酸钠(SDBS)和月桂醇聚氧乙烯(9)醚(AEO-9)进行复配实验,研究了复配液的表面张力,再向最低表面张力的复配表面活性剂溶液中投加絮凝剂聚合氯化铝(PAC)和聚丙烯酰胺(PAM),探讨絮凝剂的添加对黑烟颗粒沉降和絮凝的影响.实验结果表明:同时添加表面活性剂CTAB,SDBS和PAC,并使之浓度分别为0.5 mmol/L,0.4 mmol/L和200 mg/L时,炭黑颗粒的沉降效果最好,沉降率高达94%,且絮凝体较大,沉降时间仅为2 min。     

超声波促进城市生活污泥缺氧/好氧消化的研究

本研究将超声波预处理引入城市生活污泥缺氧/好氧消化工艺中，自主设计了容积为30 L的生活污泥超声波-缺氧/好氧消化中试系统并用以实验研究。超声波预处理的参数为超声频率28 kHz，声能密度0.15 W/mL，超声时间10 min，超声间隔12 h，污泥超声比例30%。结果表明，引入超声预处理后，缩短了污泥的稳定时间，提高了污泥的消化效率。污泥消化10 d就已经达到了稳定标准，比未引入超声预处理时缩短了12 d，而MLVSS最大去除率提高了11%，达到了55.10%。超声波的引入，对污泥缺氧/好氧消化系统中污泥上清液溶解性COD（SCOD）的变化趋势影响比较明显，而对上清液的pH、氨氮和TP的变化趋势没有明显影响。     

CPB改性沸石对磷酸盐的吸附-解吸性能研究

采用溴化十六烷基吡啶(CPB)对天然沸石进行改性,并考察了CPB改性沸石对磷酸盐的吸附-解吸性能。结果表明,CPB改性沸石对磷酸盐具备一定的吸附能力,且吸附行为满足Langmuir等温吸附模型;粒径、改性剂投加量、反应温度、pH值及共存阴离子等因素均会影响CPB改性沸石对磷酸盐的吸附能力;减小粒径和降低反应温度均有利于CPB改性沸石对磷酸盐的吸附去除;粒径≤0.18 mm CPB改性沸石吸附磷酸盐较优的改性剂投加量为250 mmol/kg;当溶液的初始pH值位于4~10之间时CPB改性沸石对磷酸盐的吸附能力随pH值的增加而增强;SO42-的存在会明显降低CPB改性沸石对磷酸盐的吸附效率,而提高溶液的pH值有助于消除SO42-存在对CPB改性沸石吸附磷酸盐的负面影响;HCO3-的存在会一定程度上抑制CPB改性沸石对磷酸盐的吸附去除,而提高溶液的pH值无法消除HCO3-存在对CPB改性沸石吸附磷酸盐的负面影响;CPB改性沸石吸附磷酸盐后一定条件下可以重新解吸出来,且随着解吸液SO42-浓度的增加解吸率明显增大。     

H(+)/phenanthrene symporter and aquaglyceroporin are implicated in phenanthrene uptake by wheat (Triticum aestivum L.) roots

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous organic pollutants that are toxic to human and nonhuman organisms. Dietary intake of PAHs is a dominant route of exposure for the general population because food crops are a major source of dietary PAHs. The mechanism for crop root uptake of PAHs remains unclear. Here we reveal that wheat root uptake of PAHs involves active and passive processes. The passive uptake is mercury and glycerol dependent. Mercury and glycerol inhibit uptake, indicating that aquaglyceroporins sensitive to mercury contribute to passive uptake. Active uptake is mediated by a phenanthrene/H symporter. The electrical response of wheat roots triggered by phenanthrene consists of two sequential phases: depolarization followed by repolarization. The depolarization is phenanthrene concentration dependent, with saturation kinetics that have an apparent of K(m) 10.8 μmol L(-1). As uptake proceeds, external solution pH increase is noticed. Lower pH favors the uptake. Vanadate and 2,4-dinitrophenol suppress the electrical response to phenanthrene and phenanthrene uptake, suggesting that plasma membrane H(+)-ATPase is involved in the establishment of an electrochemical proton gradient acting as a driving force for active uptake. Therefore, it is suggested that aquaglyceroporin and phenanthrene/H symporter are implicated in phenanthrene uptake. Our results provide insight into PAH uptake mechanism in wheat roots that is relevant to strategies for reducing PAH accumulation in wheat for food safety, improving phytoremediation of PAH-contaminated soils or water by agronomic practices and genetic modification to target remedial plants for higher PAH uptake capacity.     

添加氮损失抑制剂对蓝藻泥堆肥质量的影响

对脱水蓝藻进行大型生产性堆肥实验。研究堆肥过程中,氮损失抑制剂过磷酸钙的添加对堆肥物料各类理化性质的影响。研究结果表明,过磷酸钙加入的处理组与未加过磷酸钙的对照组堆制37 d后堆肥物料均可腐熟,且堆肥肥效均符合NY525-2002的相关要求。添加过磷酸钙处理组有机质含量为490 g/kg,全N、全P和全K含量分别为20.75、10.02和11.32 g/kg,总养分含量达到9.77%,堆肥品质明显优于对照处理。同时,在微生物的作用下,对照组中微囊藻毒素MC-RR与微囊藻毒素MC-LR去除率分别达到89.8%与78.3%。值得一提的是,添加过磷酸钙后,MC-RR和MC-LR的去除率得到进一步提高,分别达到了92.96%和100%,较好地保证了蓝藻堆肥农用的安全性,为脱水蓝藻好氧堆肥化提供了可行性依据。     

添加剂对炭黑颗粒润湿和沉降性能的影响

为提高湿式除尘装置对炭黑颗粒物的去除效率，通过向吸收液中添加复配表面活性剂以提高吸收液对炭黑的润湿性，投加絮凝剂使进入吸收液的炭黑颗粒发生凝聚和沉降，从而使吸收液得以循环利用。其中表面活性剂的复配以非离子表面活性剂月桂醇聚氧乙烯（9）醚（AEO-9）为主，与十二烷基苯磺酸钠（SDBS）、十六烷基三甲基溴化胺（CTAB）和壬酚基聚氧乙烯醚（TX-10）分别复配，筛选出复配效果最好的一组复配液；然后投加絮凝剂，探讨絮凝剂的加入对吸收液中炭黑颗粒物絮凝沉降的影响。结果表明，在AEO-9浓度为0．05mmol／L，TX-10浓度为0．09mmol／L时，吸收液的表面张力最小，为36．75mN／m；投加无机絮凝剂聚合氯化铝（PAC）浓度为100mg／L时，经15min沉降，炭黑的沉降率可达88．1％，上清液中悬浮颗粒的平均粒径为6．36μm。     

Cost-Effectiveness of Payments for Ecosystem Services with Dual Goals of Environment and Poverty Alleviation

The goal of this article is to understand strategies by which both the environmental and poverty alleviation objectives of PES programs can be achieved cost effectively. To meet this goal, we first create a conceptual framework to understand the implications of alternative targeting when policy makers have both environmental and poverty alleviation goals. We then use the Grain for Green program in China, the largest PES program in the developing world, as a case study. We also use a data set from a survey that we designed and implemented to evaluate the program. Using the data set we first evaluate what factors determined selection of program areas for the Grain for Green program. We then demonstrate the heterogeneity of parcels and households and examine the correlations across households and their parcels in terms of their potential environmental benefits, opportunity costs of participating, and the asset levels of households as an indicator of poverty. Finally, we compare five alternative targeting criteria and simulate their performance in terms of cost effectiveness in meeting both the environmental and poverty alleviation goals when given a fixed budget. Based on our simulations, we find that there is a substantial gain in the cost effectiveness of the program by targeting parcels based on the “gold standard,” i.e., targeting parcels with low opportunity cost and high environmental benefit managed by poorer households.     

微波-H202-膨胀石墨协同催化氧化处理甲基橙废水

为了研究膨胀石墨、微波和H2O2在催化氧化体系中的协同作用,采用微波法制备膨胀石墨,通过单因素条件实验,研究了微波、H2O2和膨胀石墨协同催化氧化法处理甲基橙废水工艺,探讨了各种因素协同作用对废水脱色效果的影响.实验结果表明,微波- H2O2 -膨胀石墨氧化体系能高效快速地降解废水中的甲基橙,在50 mL 初始pH 为...     

湘江株洲段丰水期镉污染负荷总量测算及分配

以2010年8月湘江干流株洲段代表性断面水质与底泥监测资料以及其他资料为基础,采用WASP7模型模拟该江段丰水期镉浓度,并进行镉污染负荷测算与分配。研究结果表明,WASP7模型较好地重现了镉浓度的变化规律,8月份该河段上游镉入流量2 446.33 kg,下游出流量3 076.44 kg,区间增量630.12 kg,其中点源负荷量241.67 kg,占38.4%,面源负荷量304.49 kg,占48.3%,内源负荷量为83.96 kg,占13.3%。