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1.
为有效、快速、廉价地修复废水和土壤铅污染,研究了一种重金属铅修复去除材料(超顺磁微纳米Fe3O4@Ca10(PO4)6(OH)2功能材料,MFH)的投加量、Pb2+初始浓度、吸附时间、pH、离子强度以及有机质浓度等因素对废水、污染土壤中Pb2+的修复效果。结果表明,MFH对溶液中的Pb2+的吸附满足准二级动力学模型,在10 min左右达到吸附平衡,最大吸附量181.6mg·g-1;在pH2.00～5.00范围内Pb2+去除率随溶液pH的增加而下降;溶液中离子强度增大会抑制MFH对Pb2+的去除率,而溶液中有机质含量增加则能有效提高MFH对Pb2+的去除率。MFH对农田和工业园区铅污染土壤均有较好的去除效果,添加重金属活化剂EDTA能明显提高MFH对土壤中铅的去除效果,其中对轻度铅污染的农田土壤中铅总量去除... 相似文献
2.
以羊栖菜粉为吸附剂,研究羊栖菜粉对水溶液中Cu2+的吸附特性及吸附机理,考察羊栖菜对重金属铜的吸附能力,以扩展羊栖菜的综合利用范围。采用控制变量法考察pH值、吸附剂浓度、金属离子初始浓度和离子强度等环境因素对水溶液中Cu2+去除效果的影响,通过模拟吸附动力学和热力学试验考察羊栖菜粉对Cu2+的吸附特性,并采用SEM、FTIR等方法初步分析了羊栖菜粉对Cu2+的吸附机理。结果表明,在吸附温度35℃、初始浓度50 mg·L-1、吸附剂浓度1 g·L-1条件下,羊栖菜粉对Cu2+的去除率可达89.27%。当吸附时间为10 min时,Cu2+去除率达总去除率的90%以上;当吸附时间为60 min时,基本达到吸附平衡。羊栖菜粉吸附Cu2+的动力学数据符合准二级动力学模型,相关系数均在0.999 0以上。Langmuir可以很好地拟合热力学试验得到的平衡数据,理论最大吸附容量为71.17 mg·g-1。羊栖菜粉对Cu2+的吸附有多种反应参与,参与络合反应的官能团主要有-OH、-NH、-COO-。羊栖菜粉对Cu2+的去除率较高,吸附性能良好,可通过解吸实现吸附剂的再生。 相似文献
3.
58个不同品种甘薯茎叶营养与功能成分的研究 总被引：1，自引：0，他引：1
为了明确不同品种甘薯茎叶的营养与功能成分组成,本试验系统比较了58个不同品种甘薯茎叶中的粗蛋白、粗脂肪、膳食纤维、维生素、多酚类物质、黄酮类物质含量及抗氧化活性。结果表明,甘薯茎叶富含粗蛋白(9.35~38.45 g·100 g-1 DW)、粗脂肪(1.36~12.30 g·100 g-1 DW)、总膳食纤维(35.30~45.0 g·100 g-1 DW)、维生素C(1.47~131.64 mg·100 g-1 DW)、β-胡萝卜素(6.75~59.35 mg·100 g-1 DW)及维生素E(0.39~23.30 mg·100 g-1 DW);湛薯01-2品种甘薯茎叶中总酚含量(21.39 g CAE·100 g-1 DW)及抗氧化活性(40.28 g TE·100 g-1 DW)最高。抗氧化活性与营养成分之间的相关性分析结果表明,甘薯茎叶中主要的抗氧化活性物质为多酚类物质(R2=0.748)。本研究为甘薯茎叶的合理开发利用提供了一定的指导。 相似文献
4.
为制备可用于分析过氧化氢(H2O2)的荧光传感器,本研究利用壳聚糖与DL-酒石酸为反应前体,水热处理制备了新型氮掺碳量子点(CDs),能够高效、简便地检测食品中的H2O2含量;并采用透射电镜(TEM),以及傅里叶变换红外光谱(FTIR)等方法进行分析表征。结果表明,CDs的荧光量子产率约为5.22%,粒径约为20 nm,而且具有石墨烯结构,其表面也含有较丰富的羟基、氨基和羧基等功能性官能团。此外,Fe3+可以猝灭CDs溶液的荧光,而Fe2+几乎不影响;按照CDs与Fe3+混合后荧光几乎消失时的浓度配比,将Fe3+替换成同等浓度Fe2+再分别加入不同浓度的H2O2,快速混均后测量其在320 nm激发光下的荧光发射图谱,绘制标准曲线,H2O2浓度在0~60 μmol·L-1内线性关系良好,相关系数R2约为0.990 0,检测限约为0.65 μmol·L-1。本研究结果为快速检测食品中的H2O2提供了一定的理论依据。 相似文献
5.
为探讨周年不同施氮组合对冬小麦-夏大豆轮作体系土壤氮素及产量影响规律,于2017—2018年,在伊宁县农业科技示范园内开展大田试验,以冬小麦-夏大豆轮作为研究对象,在前茬麦季设置4个施氮水平:0(N0)、104(N1)、173(N2)、242 kg·hm-2(N3);后茬大豆设置3个施氮水平:0(S0)、69(S1)、138 kg·hm-2(S2),研究周年不同施氮组合对两季作物收获后农田0~100 cm土层土壤硝态氮(NO3--N)、铵态氮(NH4+-N)含量、无机氮残留量及产量的影响。结果表明,冬小麦不同施氮水平土壤NO3--N及NH4+-N含量均在20~40 cm土层达到最大值,且N3的土壤NO3--N和NH4+-N含量最高,分别达到14.65 mg·kg-1和4.26 mg·kg-1,土壤NO3--N含量平均分别较N0、N1、N2增加了92.86%、44.69%和17.03%,土壤NH4+-N平均依次增加了69.95%、26.10%和8.46%;而冬小麦施氮量越高,其土壤无机氮残留量越大,以麦季N3平均最高,为200.62 kg·hm-2。此外,前茬麦季施氮还能影响后茬大豆土壤中NO3--N、NH4+-N含量及无机氮残留量;夏大豆的土壤NO3--N和NH4+-N含量也在20~40 cm土层达到最大值,且N3S2的土壤NO3--N、NH4+-N含量及无机氮残留量最大,平均分别为18.61 mg·kg-1、 5.10 mg·kg-1、258.36 kg·hm-2。在麦季施氮173 kg·hm-2时(N2),冬小麦产量最高,平均为7 828.64 kg·hm-2,平均分别较N0、N1、N3增加35.45%、16.77%、6.26%;且在此基础上夏大豆当季再施氮69 kg·hm-2时(S1),夏大豆获得产量最高,平均为2 988.93 kg·hm-2,其周年总产量也达到最高平均,为10 817.5 kg·hm-2。综上所述,麦季施氮173 kg·hm-2,豆季施氮69 kg·hm-2既有利于提高麦豆周年产量,又能减少土壤氮素的残留量,可为当地一年两熟制高效施氮制度提供一定的参考标准。 相似文献
6.
为探究西兰花叶中生物活性成分的具体含量,以西兰花叶为原材料,对西兰花叶中萝卜硫素、总酚、总黄酮、总蛋白质的含量和组成进行了测定与分析。结果表明,西兰花废弃叶中萝卜硫素含量为92.50 μg·g-1 DW,总酚含量为3.15 mg·g-1 DW,总黄酮含量为2.48 mg·g-1 DW,总蛋白质含量为89.38 mg·g-1 DW,蛋白质组成中核酮糖-1,5-二磷酸羧化酶/加氧酶(Rubisco)所占比例最大。本研究明确了西兰花叶片中4种生物活性成分的具体含量,为进一步开发利用西兰花废弃物提供了一定的数据支持。 相似文献
7.
为阐明火龙果种子清蛋白的理化性质和生物学活性,本研究从红心火龙果中纯化获得种子清蛋白(HPA),分析其分子量、氨基酸组成、同源性及胰蛋白酶抑制活性。结果表明,HPA由两条分子量为12.6、13.2 kDa的多肽链(HPA-1,HPA-2)组成。 HPA富含谷氨酸(6.297 g·100g-1)、精氨酸(3.992 g·100g-1) 和天冬氨酸(2.694 g·100g-1)。 HPA与来自甜菜和菠菜2S种子贮藏蛋白具有高度相似性。HPA-2显示出较高的胰蛋白酶抑制活性,比活力为9.19×103 TIU· mg-1,纯化倍数为1.86。经大豆胰蛋白酶抑制剂-琼脂糖凝胶柱纯化的组分HPA-2-1是胰蛋白酶竞争性抑制剂,抑制常数(Ki)为0.62 nmol·L-1, 具有Kunitz型抑制剂的摩尔比曲线。 HPA-2-1在一定的pH值(2~10)和温度(30~70℃)范围内具有稳定的抑制活性,且抑制活性几乎不受二硫苏糖醇(DTT)的影响。本研究为挖掘火龙果种子资源,丰富胰蛋白酶抑制剂的种类提供了参考。 相似文献
8.
为明确青海不同品种黑青稞的营养及化学成分含量,筛选优异种质资源,本研究开展了12种黑青稞营养及化学成分分析与评价。结果表明,参试黑青稞蛋白、总淀粉、直链淀粉、粗脂肪、粗纤维、灰分、β-葡聚糖含量在部分品种间存在显著差异(P<0.05),黑青稞具有较高含量的蛋白质(12.19%~14.07%)、纤维(2.13%~3.64%)、直链淀粉(18.96%~25.94%)和β-葡聚糖(3.91%~7.50%);参试黑青稞中Ca、K、Zn含量存在品种间显著差异(P<0.05),其余测定的矿物质含量存在部分品种间显著差异(P<0.05),其中K(581.42 mg·100g-1)、Mg(171.90 mg·100g-1)、Ca(90.28 mg·100g-1)、Na(17.33 mg·100g-1)含量较高;参试黑青稞蛋白中总必需氨基酸含量平均值为319.90 mg·g-1(接近WHO/FAO推荐值360 mg·g-1),第一限制性氨基酸为赖氨酸,第二限制性氨基酸为甲硫氨酸和胱氨酸,第三限制性氨基酸为苏氨酸;参试部分黑青稞品种的总酚、游离酚、结合酚、总黄酮、游离黄酮、结合黄酮及花色苷含量存在显著差异(P<0.05);主成分筛选出950、Z536、Z533黑青稞综合品质较优,聚类分析将12个黑青稞品种分为4类,第1类蛋白质、多酚、黄酮、β-葡聚糖含量较高;第2类花色苷、氨基酸含量较高;第3类纤维含量较高;第4类淀粉含量较高。本研究结果为黑青稞营养功能品质评价及加工利用奠定了基础,也为特异青稞资源的筛选提供了参考。 相似文献
9.
为探究酸性乙醇溶液(乙酸+乙醇+水)提取莲衣粉(LSPW)多酚的最佳工艺,明确莲衣粉多酚提取物(PEL)作为天然食品抗氧化剂的应用潜力,本研究在单因素试验基础上,通过响应面分析法优化莲衣粉多酚的提取工艺,并对PEL进行体外抗氧化研究。结果表明,莲衣粉多酚的最佳提取工艺为乙醇浓度41%、液料比59 mL·g-1、乙酸添加量1.56 mL·100mL-1、提取温度70℃、提取时间20 min。在此条件下,莲衣粉多酚得率达9.65%。PEL的多酚含量达24.03%,且其具有较强的清除DPPH自由基(IC50=0.032 mg·mL-1)、还原Fe3+(eq=268.64 mg AAE·g-1)的能力,抑制脂质氧化能力分别相当于叔丁基对苯二酚(TBHQ)、叔丁基羟基茴香醚(BHA)的37.12%、39.20%(硫氰酸铁法)与72.92%、67.60%(硫代巴比妥酸法)。本研究为莲衣粉多酚的开发利用及PEL作为潜在的天然食品抗氧化剂提供了理论基础。 相似文献
10.
为探究超声辅助酶解法提取玉米皮多酚的最优工艺,并探讨其体外抗氧化活性,以玉米皮多酚提取量为响应值,分别考察超声时间、提取温度、料液比和酶添加量4个因素对提取效果的影响。在单因素试验的基础上,采用中心组合响应面分析法对提取工艺进行优化。结果表明,最佳提取条件为:超声时间6.5 min、酶解温度55℃、液料比41 mL·g-1、木聚糖酶添加量2.10%,此条件下,玉米皮多酚提取量最高,为7.26 ± 0.15 mg·g-1,与响应面预测值7.17 mg·g-1相近。DPPH·和ABTS+·清除法抗氧化试验结果表明,玉米皮多酚具有较强的抗氧化能力,可作为潜在天然抗氧化剂应用于食品行业。本研究结果为玉米加工副产物玉米皮综合应用提供了理论依据。 相似文献
11.
Gibbs free binding energy and adsorption energy between cations and charged soil particles were used to evaluate the interactions between ions and soil particles. The distribution of Gibbs free adsorption energies could not be determined experimentally before the development of Wien effect measurements in dilute soil suspensions. In the current study, energy relationships between heavy metal ions and particles of Hapli-Udic Argosol （Alfisol） and Ferri-Udic Argosol were inferred from Wien effect measurements in dilute suspensions of homoionic soil particles （〈 2 μm） of the two soils, which were saturated with ions of five heavy metals, in deionized water. The mean Gibbs free binding energies of the heavy metal ions with Hapli-Udic Argosol and Ferri-Udic Argosol particles diminished in the order of Pb^2＋ 〉 Cd^2＋ 〉 Cu^2＋ 〉 Zn^2＋ 〉 Cr^3＋, where the range of binding energies for Hapli-Udic Argosol （7.25-9.32 kJ mol^-1） was similar to that for Ferri-Udic Argosol （7.43-9.35 kJ mol^-1）. The electrical field-dependent mean Gibbs free adsorption energies of these heavy metal ions for Hapli-Udic Argosol and for Ferri-Udic Argosol descended in the order： Cu^2＋ 〉 Cd2^＋ 〉 Pb^2＋ 〉 Zn^2＋ 〉 Cr^3＋, and Cd^2＋ 〉 Cu^2＋ 〉 Pb^2＋ 〉 Zn^2＋ 〉 Cr^3＋, respectively. The mean Gibbs free adsorption energies of Cu^2＋, Zn^2＋, Cd^2＋, Pb^2＋, and Cr^3＋ at a field strength of 200 kV cm^-1, for example, were in the range of 0.8-3.2 kJ mo1^-1 for the two soils. 相似文献
12.
Influence of phosphate on cadmium sorption by calcium carbonate 总被引：1，自引：0，他引：1
Laboratory investigation was conducted to investigate the mechanism of cadmium sorption by pure calcium carbonate and to examine whether, reaction products of phosphate with calcium carbonate serve as a sink for sorption of toxic heavy metal cations like cadmium. The phosphatization of calcium carbonate (G.R) was carried out by treating it with orthophosphoric acid in Ca:P ratio of 5:3, 3:2, 4:3 and 1:1, representing the Ca–P ratios of carbonate apatite, tricalcium phosphate, octacalcium phosphate and dicalcium phosphate and then equilibrated for two months. The X-ray diffraction of the phosphate reaction products revealed that calcite along with monetite, brushite and carbonate apatite were present in each case. The cadmium was effectively retained on CaCO3 by the mechanism of chemisorption at lower Cd2+ concentrations as the pH of the equilibrium system remained constant (8.6) up to initial Cd2+ concentrations of 10−4 mol, coinciding to 100% sorption of Cd2+ from the solution. At higher concentrations, precipitation of CdCO3 on CaCO3 surface or as a separate phase predominated. Enrichment of CaCO3 with P reduced the Cd-sorption. The chemisorption of Cd probably involved the exchange of Ca2+ by Cd2+ from CaCO3 surface. The Cd2+ concentration in equilibrium solution followed the solubility diagram of CdCO3 at pH ≤ 8.6, whereas the concentration of Ca2+ started deviating from the solubility line at pH ≤ 8.2. 相似文献
13.
Interactions of three heavy metal ions, Cu2+, Cd2+, and Pb2+, and, for comparison, Na+ with electrodialytic clay fractions (less than 2 μm in diameter) of four paddy soils as well as a yellow-brown soil as a control soil were evaluated based on measurements of the Wien effect in dilute suspensions with a clay concentration of 10 g kg?1 in four nitrate solutions of 2 × 10?4/z mol L?1, where z is the cation valence, and a nitric acid solution of 3 × 10?5 mol L?1. Field strengths ranging from 15 to 230 kV cm?1 were applied for measuring the electrical conductivities (ECs) of the suspensions. The mean free binding energies between the various cations and all of the soils determined from exchange equilibrium increased in the order: Na+ < Cd2+ < Cu2+ < Pb2+. In general, the ECs of the suspensions in the sodium nitrate solution were smaller than those of the suspensions in the heavy metal solutions because of the lower electrophoretic mobility of sodium compared to the divalent cations. In terms of relative electrical conductivity-field strength relationships, relative electrical conductivity (REC) of suspensions containing various cations at field strengths larger than about 50 kV cm?1 were in the descending order: Na+ > Cu2+ > Cd2+ > Pb2+ for all tested soils. A characteristic parameter of the REC-field strength curves, ΔREC200, REC at a field strength of 200 kV cm?1 minus that at the local minimum of the concave segment of the REC-field strength curves, characterized the strength of adsorption of the cations stripped off by the applied strong electrical field, and for all soils the values of ΔREC200 were generally in the order: Na+ < Cu2+ ≤ Cd2+ ≤ Pb2+. 相似文献
14.
G.K. Asamoa 《Geoderma》1973,10(4):285-297
The distribution of particle size and Na-dithionite-extractable (di-Fe2 O3) and NH4-oxalate-extractable (ox-Fe2O3) iron oxides were investigated in twelve soil profiles representing latosols and groundwater laterites. Soil profiles studied were selected from the major ecological zones of Ghana. The pattern of distribution of free Fe2O3 was closely related to that of clay (< 2μ) in soil profiles of the humid forest zones where clay content was more than 40% in the B horizons. In soil profiles of the relatively dry savannah zones with less than 40% clay in the B horizon, the pattern of distribution of free Fe2O3 was closely related to that of silt (2–20 μ). The amount of free Fe2O3 in the soils appeared to be related to kind of parent rock or parent material and to climatic factors operating in the various ecological zones. Using the amount of di-Fe2O3 in the B horizon as a basis for assessing the relative degrees of pedogenesis in soil profiles developed from the same kind of parent material, it was concluded that soil profile development had progressed most in the rain forest zone. Free Fe2O3 was considered as having reached an advanced stage of crystallinity or aging in most of the soils because of the low ox-Fe2O3/di-Fe2O3 ratios in the solums of most of the soil profiles. Soils studied were placed in the ferrallitic and ferruginous soil classes of D'Hoore. The great soil groups could not be characterized by depth function curves of free Fe2O3. However, it was proposed that the relative amounts of di-Fe2O3 in the B horizons of the soil profiles could be used as a basis for classifying these soils at the family level. 相似文献
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为探究远红光对植物生长的影响,采用“燃烧法+高温二次烧结”的方法制备了ZnGa2O4:Cr3+,Ge4+,Li+(ZGO:Cr3+,Ge4+,Li+)荧光粉,将自制的荧光粉材料涂覆在410 nm的蓝紫光LED芯片上,封装成发射主峰位于710 nm左右的LED远红光器件,并进一步组装成LED植物生长灯作为直接光源。以番茄(Solanum lycopersicum)品种红矮生为试材,白光(W)为对照(CK),设置3个处理:T1:红蓝组合光(1R1B)加远红光(光质比为3:1);T2:红蓝组合光(1R1B);T3:白光加远红光(光质比为3:1),研究红蓝组合光(1R1B)和远红光对番茄生理周期、农艺性状、光合色素和番茄果实主要品质的影响。结果表明,与CK相比,T1处理可显著缩短番茄生理周期,T1、T2和T3处理对番茄农艺性状中的株高有抑制作用。添加远红光降低了光合色素的含量,但提高了番茄果实中可溶性糖、番茄红素和维生素C的含量,特别是在红蓝组合光与远红光的共同作用下,可溶性糖含量提高效果最明显,达到CK的3.3倍。添加远红光能够促进维生素C和番茄红素含量增加;红蓝组合光则有利于番茄红素的积累。综上,采用ZGO:Cr3+,Ge4+,Li+远红光荧光粉激发型LED植物灯能调控番茄开花时间,缩短其生理周期,提高番茄果实品质。本研究结果为提高番茄以及其他园艺作物的品质提供了一种新的光照手段,具有广阔的应用前景。 相似文献
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在尿素减量施用条件下,探究添加酸化沸石(SF)对氮素淋失及籽粒氮肥利用率的影响。通过等温吸附试验,结合土柱淋溶和玉米盆栽试验,研究酸化沸石对NH_4+—N和NO_3-—N的吸附性能,以及不同施氮梯度下,酸化沸石对氮素淋失和氮肥利用率的影响,试验分别设置农民习惯施肥(CN)、氮肥减量15%(CN1)、氮肥减量30%(CN2)3个施氮梯度并分别添加土重0.2%的酸化沸石(CN+SF、CN1+SF、CN2+SF)。结果表明,酸化沸石对NH_4+—N和NO_3-—N的最大吸附量分别为25.44,31.59 mg/g,吸附过程可用Langmuir模型较好拟合。在减氮15%和30%时,添加酸化沸石,使NH_4+—N累计淋失量较CN1、CN2分别降低7.10%,8.76%。在减氮30%时,酸化沸石可有效降低NO_3-—N累计淋失量,较CN2处理减少15.90%。酸化沸石可有效提高土壤氮素含量和玉米籽粒氮肥利用率,添加酸化沸石(CN+SF、CN1+SF、CN2+SF)较单施尿素(CN、CN1、CN2)籽粒氮肥利用率分别提高10.37%,20.79%,47.14%。综上,酸化沸石在减施尿素条件下可有效降低土壤氮素淋失,提高玉米籽粒氮肥利用率,具有一定的农艺价值。 相似文献