Linking Watershed Nutrient Loads and Riverine Export to Reservoir Eutrophication:The Case of Shanzai Reservoir, Fujian Province

建立流域氮磷输出、河流输送与入库通量的分析方法,以福建省山仔水库为例,基于gIS技术分析乡镇、子流域的氮磷污染分布和来源构成,识别关键源区并探讨库区水质与流域污染输出和河流输送之间的关联性。结果表明,2009年山仔流域单位面积总氮输出负荷为13.4 kg n·HM-2·A-1(生活污水和化肥流失占64%),总磷输出负荷为0.82 kg P·HM-2·A-1(畜禽养殖和生活污水占90%),入库氮、磷负荷分别为3248 T n·A-1和192 T P·A-1,其中河流输入占62%和89%,环库区面源污染贡献小于2%;不同乡镇单位面积氮输出负荷为3.54~20.0 kg n·HM-2,磷输出负荷为0.38~2.50 kg P·HM-2,其中日溪乡和霍口乡临近库区,化肥流失与畜禽养殖污染最重。上游乡镇污染较轻,但生活污水比重大(42%~84%)。皇帝洞溪子流域污染最重(19.4 kg n·HM-2;1.95 kg P·HM-2),其次是霍口溪中下游和日溪子流域。库区总氮高值出现在坝区和日溪湾汊,总磷高值在小沧至霍口溪七里入口之间,水质有明显分区,与流域污染分布、河流输送和库区沉积物的释放相关联,河流输入对库区富营养化起决定性作用。流域氮磷输出负荷比值平均为16,库区水中氮磷比值在15~20之间,意味着该生态系统处于磷的弱限制,水华爆发风险较大,建议采取“分区整治流域污染、氮磷联合削减、畜禽养殖和磷肥流失优先控制“的富营养化防控策略。A quantitative analysis of watershed nitrogen(N)and phosphorus(P)loads,riverine export and other inputs to reservoir was conducted for Shanzai reservoir in Fujian Province.Spatial variation of N and P pollution and major components were interpreted at town and sub-watershed scale using GIS techniques,and the critical source area(CSA)was indentified.The linkage between reservoir water quality and watershed nutrients loading and riverine export fluxes was examined.Results revealed that total N and P loads per unit area of the Shan zai watershed were 13.4 kg N·hm-2·a-1and 0.82 kg P·hm-2·a-1,respectively.Domestic sewage and fertilizer runoff accounted for 64% of total N load,and livestock waste and domestic sewage shared 90% of total P load.Total N and P loads to the Shanzai reservoir were 3248 t N·a-1 and 192 t P·a-1,62% and 89% of which were through riverine transport and the remainder mostly from sediment release.Less than 2% of in puts were from non-point sources in the surrounding area.Town-level N and P loads per unit area ranged from 3.54~20.0 kg N·hm-2and 0.38~2.50 kg P·hm-2,respectively.Two towns(Rixi and Huokou) adjacent to the reservoir were identified as CSA of fertilizer runoff and livestock waste,while human sewage dominated the nutrient load(42%~84% of total)in other towns in the upstream area.Huangdidong subwatershed was the most polluted catchment(19.4 kg N·hm-2;1.95 kg P·hm-2),followed by the lower reaches of Huokou River and Rixi subwatershed.The high value of total N concentration was observed near the dam head and Rixi inlet,whereas high total P concentration was found in channel from Huokuo inlet to Xiaocang.The spatial variation of the nutrients level in the reservoir was highly associated with watershed nutrient loads,riverine export and sediment-water exchange,indicating that riverine input is the decisive factor contributing to eutrophication of the reservoir.The average N∶P ratio of the nutrient load was calculated as 16 for the whole watershed,which combined with the TN∶ TP ratio of 15~20 observed in reservoir surface water suggested that the reservoir ecosystem was weakly limited by P and tended to stimulate algal bloom.To mitigate eutrophication,reduction of both N and P pollution should be considered in those CSAs,with a priority given to P pollution from livestock and phosphate fertilizer loss.公益类科研院所专项(2011R1004-2); 中央高校基本科研业务费专项(厦门大学基础创新科研基金项目)(2012121053

Extraction of insecticidal toosendanin from meliaceae by supercritical CO_2

王宏涛(1968-),男,博士,副教授,主要研究方向为天然产物的提取分离等, E-mail: [email protected]。[中文文摘]苦楝素是楝科植物中制备植物源农药的主要杀虫成分。针对不同种源楝树的皮、叶及果实,采用溶剂浸提法提取筛选苦楝素含量较高的种源作为实验原料,采用乙醇提取,考察液固质量比、提取时间和提取次数等参数对苦楝素提取率的影响。当液固质量比为25∶1、提取时间为4 h、提取次数为3次时,苦楝素的提取率达18%。进一步采用超临界CO2萃取考察压力、温度、萃取时间、原料粒径和夹带剂等参数对苦楝素萃取率的影响,当温度为40℃、压力为20 MPa、时间为2.0 h、原料粒径为40目、夹带剂乙醇质量为CO2质量的12.5%时,苦楝素的萃取率达43.5%。在对萃取液结晶纯化中成功分离得到质量分数达98%的苦楝素。[英文文摘]Toosendanin is the main insecticidal component of meliaceae plants for producing botanical insecticides.The extraction of toosendanin from the parks,leaves and fruits of the various meliaceae plants was studied by using ethanol,and the part of the meliaceae plants with the maximal mass fraction of toosendanin was selected as experimental materials.The effects of the mass ratio of liquid to solid,extraction time,and extraction times on the yield of toosendan were investigated by using ethanol extraction method. The yield of toosendanin is up to 18% at them ass ratio of liquid to so lid of 25:1, extraction time of 4h and extract ing 3 times. The effects of pressure, temperature, extraction time, and the partic le size of materials and the dosage of mod if iers on the yield of toosendanin w ere investigated bym eans of supercritical CO2 extraction. The yield of toosendan in is up to 43.5% when ethanol is used as mod ifier with its mass 12.5% of CO2 mass at temperature 40,pressure 20 MPa,extraction time 2h and material particle size 40 mesh. The toosendanin crystal with mass fraction 98% was separated from the extracts by using crystalliza tionm ethod.福建省新世纪人才支持计划项

化工实验教学体系模块化构建探索与实践

厦门大学化学工程与技术实验教学中心以培养化工专业创新性人才为目标,结合化工学科知识结构分布及实验教学的特点,对化工实验的教学内容、教学模式及师资队伍建设进行了改革,构建了"层次化、模块化"的教学体系,切实有效地提高了实验教学质量,以期培养新型工科人才。福建省本科高校教育教学改革研究项目(FBJG20170300

Separation and identification of auraptene from grapefruit peel oil

橙油素是广泛存在于柑橘类果实中的天然抗癌活性成分。选用SP70大孔吸附树脂分离纯化葡萄柚精油中的橙油素,该树脂对于橙油素的吸附容量和解吸率分别达到14.53 Mg/g和83.32%,并成功地从树脂床层的洗脱液中结晶分离出橙油素晶体。对所得晶体分别采用差示扫描量热仪(dSC)、紫外吸收光谱(uV)、红外吸收光谱(Ir)、电喷雾质谱(ESI-MS)进行定性分析,分析结果与橙油素标准品相符合。进一步采用高效液相色谱(HPlC)对所得晶体进行定量分析,结果表明所得晶体中橙油素的质量分数可达85%。Auraptene exists widely in the peels and juice sacs of citrus species and is reported to be an effective inhibitor of chemical carcinogenesis in some rodent models.The separation and purification of auraptene from the grapefruit peel oil was performed by SP70 macroporous resin adsorption.The amount adsorbed and the recovery of auraptene were 14.53 mg/g and 83.32% respectively.Auraptene was crystallized out from the concentrated eluate of macroporous resin bed successfully.Differential scanning calorimetric(DSC),ultraviolet spectrum(UV),infrared spectroscopy(IR) and electrospray ionization mass spectroscopy(ESI-MS) were all used to analyze the obtained crystals qualitatively.The analytical results are in accordance with that of auraptene standard.Furthermore,high performance liquid chromatography(HPLC) was utilized to quantify auraptene of the crystals obtained.The mass fraction of auraptene in the obtained crystals can reach 85%.福建省新世纪人才支持项目(0000-X04157

A Study on the mechanisms of eutrophication of a shallow upstream lake in the Jiulong River Catchment

基于对九龙江上游龙潭湖富营养化水体和沉积物现状的监测结果,通过与国内富营养化深水湖库和流域下游大型富营养化浅水湖泊进行对比,深入探讨了流域上游浅水湖泊富营养化发生的原因及主导机制.流域上游浅水湖泊具有外源污染物输入较少的特点,较下游大型浅水湖泊更易受温度等气候条件和沉积物氧化还原状态的影响,以及外源输入总磷控制具有较强的滞后效应,因此对流域上游浅水湖泊富营养化的控制必须重视内源营养盐释放,特别是结合态磷的内源释放问题.Based on site monitoring chemical data of lake water and sediments during an algal bloom in the Longtan Lake,causes and mechanisms of eutrophication in shallow upstream lakes were discussed by comparing the Longtan Lake in upstream of the Jiulong River with deep eutrophic lakes and large shallow downstream eutrophic lakes in China.The shallow upstream lake is characterized as relatively simple nutrient inputs and high susceptivity to climatic variability(such as temperature),redox conditions,and strong lag effects of the external total phosphorus inputs.Therefore,attention must be paid to the sediments nutrient releases,especially,the bound phosphorus of sediments when remediating eutrophication in shallow upstream lakes.国家自然科学基金资助项目(41175130);教育部新世纪优秀人才支持计

增强型地热系统热流耦合水岩温度场分析

增强型地热系统(Enhanced Geothermal System,简称EGS)作为深层地热资源开采最有效方法已成为国际研究热点.其中多场耦合是EGS研究中的关键部分,但目前对最基础和最重要的热流耦合研究仍不充分,特别是对热流耦合下热传导过程和采热效率的研究还不透彻.本文构建了针对EGS单裂隙热流耦合的数学模型,模型主要控制热流耦合时水岩温度场的演化,以展现热流耦合下的热传导过程,并以此计算了裂隙宽度和裂隙水流速率对水岩温度场的影响,分析了裂隙特征对采热效率的影响.计算表明,在特定的开采条件下,都有相应的岩体温度场影响半径;热量从高温岩体传至裂隙流体的过程显示为进水口为低温区,以水流方向为轴,向两侧岩体对称展开的三角形热传导模式;裂隙宽度和裂隙流体速度对裂隙两侧的岩体温度场和采热半径产生明显影响,但裂隙长度总体上对采热率表现为正效应,而裂隙宽度和裂隙流体速度在一定范围内对采热率表现为负效应;裂隙宽度与裂隙流体速度对水岩温度场具有完全一致的影响效果.模型的对比验证确认了本模型的合理性和优越性.文中最大的创新点和亮点是首次推导给出了EGS热流耦合水岩温度场演化特征的简明数学表达式,另一亮点是基于岩体热传导系数来考虑耦合过程的热传导量

An apparatus for high-pressure isothermal crystallization study and its tentative application

提出用偏光显微镜研究高压等温结晶的研究方法,初步建立了用于研究高压结晶行为的装置,用其考察高压CO_2中肉豆蔻酸的等温结晶行为。通过分析结晶过程,得到其结晶生长速率。结果表明,一定压力的CO_2使肉豆蔻酸的结晶生长速率显著增高。An apparatus based on polar light microscopy technology was tentatively set up to study the crystallization behavior at high pressure.Then the apparatus was applied to the study of isothermal crystallization behavior of Myristic acid in CO_2.The growth rate was obtained by analyzing the crystallization process.Results showed that the growth rate of myrisitic acid crystals is greatly influenced by the pressure of CO_2.国家自然科学基金项目(20876127