成熟欧李果肉中单宁提取条件的优化

以成熟欧李为试验材料,乙醇、丙酮、二甲基甲酰胺为提取剂,采用L25（5^6）正交试验设计,从溶剂浓度、固液比、浸提时间、浸提温度等因素的不同水平对欧李果肉中单宁的提取条件进行了研究,结果表明：从欧李果肉中提取单宁的最佳条件为：以丙酮作提取剂,浓度60％,浸提时间4h,浸提温度30℃,固液比1：20;以乙醇作提取剂,浓度30％,浸提时间4h,浸提温度60℃,固液比1：30。     

烟草废料不同方法浸提烟碱的研究

对利用烟草废料浸提烟碱进行了研究,探讨了浸提温度、时间、液固比、浸提溶剂等因素对浸提的影响。实验结果表明,使用乙醇作为浸提溶剂,在78℃,液固比5：1,浸提时间6．5h的条件下,浸提液中烟碱质量浓度为19．3mg/mL。用微波处理时,可以用水作为浸提溶剂,浸提液中烟碱质量浓度为11．1mg/mL。     

苦瓜中苦瓜甾苷的提取工艺研究

本研究通过单因素实验和正交实验,采用HPTLC检测方法,以苦瓜甾苷浸提量为考察指标,对影响苦瓜甾苷提取效果的各因素进行了研究。结果表明各因素对苦瓜甾苷提取效果的影响程度从高到低依次为:乙醇浓度>固液比>浸提时间>浸提温度。确定了苦瓜甾苷的最佳提取工艺参数为乙醇浓度80%,浸提温度55℃,浸提时间5h,固液比1:10。     

水皂角多酚的提取工艺研究

本研究通过单因素实验和正交实验 ,以提取物中水皂角总多酚含量为考察指标 ,对影响水皂角多酚提取效果的各因素进行了研究。结果表明各因素对水皂角多酚提取效果的影响程度从高到低依次为 :浸提温度 >乙醇浓度 >固液比 >浸提时间。确定了水皂角多酚的最佳提取工艺为乙醇浓度 70 % ,浸提温度 70℃ ,浸提时间 5h ,固液比 1∶10。     

绿茶乙醇浸提技术研究

以工业生产上的水提技术为参照,以成品绿茶为材料,探讨乙醇浸提条件下,乙醇浓度、浸提温度、浸提时间、料液比、浸提次数等因子对醇提过程中茶汤品质成分动态浸出规律的影响。结果表明,采用50%乙醇、温度80℃、料液比1/25、连续2次、每次浸提20 min的浸提技术参数,茶叶各品质成分的浸出率最高,总浸出物、氨基酸、茶多酚、蛋白质、碳水化合物的浸出量分别是常规水提的1.39、1.09、1.44、1.52、1.23倍。从茶叶品质成分浸出率的角度考虑,在此技术参数下,用乙醇浸提绿茶优于水提。     

淫羊藿保健酒常温浸提工艺研究

研究了淫羊藿保健酒常温浸提的工艺条件,以淫羊藿总黄酮提取量为指标,在单因素试验的基础上,采用正交试验优化了淫羊藿保健酒常温浸提的工艺条件。结果表明,各因素对黄酮提取量影响的顺序为：乙醇浓度对黄酮提取量影响最大,料液比次之,浸提时间影响最小;最佳浸提工艺条件为：乙醇浓度为70%、料液比1∶40、浸提时间3h。在此条件下,淫羊藿总黄酮提取量为95.53±1.36mg/g。     

茶多酚提取优化工艺研究

本文研究了可食用茶多酚的提取优化工艺。萃取剂为乙醇,料液比1：15,浸提过程伴随300W超声波震荡,就乙醇的浓度、提取温度、提取时间和提取次数等因素利用正交设计筛选了茶多酚的最佳提取工艺条件,并对浸提液最佳离子沉淀方法作了比较。结果表明,茶多酚提取的最佳工艺条件为：65％的乙醇溶液作浸提剂,当浸提温度为50℃,浸提时间30min,两次超声波辐射浸提后茶多酚从粗茶叶中的提取率为20．1％。沉淀剂AlCl3和ZnSO4质量比为1：2对茶多酚的沉淀效果最佳,pH=6．0。     

新疆重瓣榆叶梅花食用色素提取方法

本文以新疆地产榆叶梅花作实验材料。从浸提剂种类、浸提温度、浸提时间、物料配比以及浸提次数进行了提取方法的比较研究。结果表明：以pH为1—2的无水乙醇为作为浸提剂,按固比1：15投料,在45℃保温浸提两次,每次2小时为最佳提取条件。     

大孔树脂吸附法分离海金沙总黄酮的研究

用大孔树脂吸附法分离海金沙中的总黄酮,考查了解吸剂浓度、吸附固液比(g/mL)、吸附温度和吸附时间对海金沙总黄酮提取率的影响。结果表明:用70%乙醇作解吸剂,在吸附固液比为1∶6(g/mL),50℃温度下吸附90 min,总黄酮提取率为1.81%。     

千年健总黄酮的超声提取工艺

为了研究千年健黄酮的超声提取工艺,通过单因素实验,研究了超声功率、超声时间、乙醇浓度、液固比等因素对黄酮得率的影响,利用正交试验对提取工艺进行优化。结果表明,各因素的影响次序为:超声功率乙醇浓度液固比超声时间,其最佳提取工艺条件为:超声功率为300W、超声时间15min、乙醇浓度50%、液固比30:1,最佳工艺条件下黄酮提取率为0.5868%。     

Development of a Laboratory-Scale Leaching Plant for Metal Extraction from Fly Ash by Thiobacillus Strains

Semicontinuous biohydrometallurgical processing of fly ash from municipal waste incineration was performed in a laboratory-scale leaching plant (LSLP) by using a mixed culture of Thiobacillus thiooxidans and Thiobacillus ferrooxidans. The LSLP consisted of three serially connected reaction vessels, reservoirs for a fly ash suspension and a bacterial stock culture, and a vacuum filter unit. The LSLP was operated with an ash concentration of 50 g liter⁻¹, and the mean residence time was 6 days (2 days in each reaction vessel). The leaching efficiencies (expressed as percentages of the amounts applied) obtained for the economically most interesting metal, Zn, were up to 81%, and the leaching efficiencies for Al were up to 52%. Highly toxic Cd was completely solubilized (100%), and the leaching efficiencies for Cu, Ni, and Cr were 89, 64, and 12%, respectively. The role of T. ferrooxidans in metal mobilization was examined in a series of shake flask experiments. The release of copper present in the fly ash as chalcocite (Cu₂S) or cuprite (Cu₂O) was dependent on the metabolic activity of T. ferrooxidans, whereas other metals, such as Al, Cd, Cr, Ni, and Zn, were solubilized by biotically formed sulfuric acid. Chemical leaching with 5 N H₂SO₄ resulted in significantly increased solubilization only for Zn. The LSLP developed in this study is a promising first step toward a pilot plant with a high capacity to detoxify fly ash for reuse for construction purposes and economical recovery of valuable metals.     

Enhanced Soil Washing for the Remediation of a Brownfield Polluted by Pyrite Ash

Soil from an abandoned/disused fertilizer plant polluted with pyrite ash containing heavy metal(loid)s (As, Cu, Pb, and Zn) was treated by means of physical and chemical washing. We first performed an exhaustive characterization of the soil-pollutant interaction, which allowed us to determine the chemical nature (complex oxyhydroxides), potential mobility and bioavailability of the pollutants (very low), as well as the grain size fractions of preferential accumulation (silt-clay fraction comprises more than 60% of the material and revealed contents well above 2.000 ppm of Cu, Zn and Pb). Soil/ash samples were subjected to a number of chemical washing trials, including leaching with 2 M HCl, 2 M NaOH and acidic process water (pH around 0). The fraction below 63 µm was mechanically separated and exposed to additional leaching tests e.g. chloridizing roasting with NaCl plus water leaching. Of all the tested procedures, the latter proved the most effective, particularly with regard to Cu and Zn recovery (recoveries up to 40% and 34%, respectively). The information gathered offers an insight into the modes and rates at which metals can be leached from pyrite ashes after chloridizing roasting as a prelude to more extensive soil washing feasibility studies focused on potential metal recovery.     

Effect of Glomus mosseae on accumulation efficiency,hazard index and antioxidant defense mechanisms in tomato under metal(loid) Stress

In the present study, the phytoremedation potential along with growth, physiological and biochemical response of tomato (Solanum lycopersicum) was assessed under heavy metal(loid) (HM) and arbuscular mycorrhizal fungus (AMF) amendment. Effect of AMF on uptake and accumulation of metal(loid)s was assessed and accumulation characteristics were expressed in terms of bioabsorption coefficient (BAC), bioconcentration factor (BCF), translocation factor (TLF) and transfer factor (TF). Results showed that AMF-inoculated plants showed not only a better growth, chlorophyll content, strengthened non-enzymatic and enzymatic defense mechanism, but also accumulated higher concentration of metal(loid)s. The correlation between biochemical and physiological parameters was significant at 0.01 level. A significant difference (p ≤ 0.001) in antioxidant enzyme activity was found on increasing metal(loid) dose and application of AMF. The accumulation of Cd and Pb in edible part exceeded the chronic reference dose stated by USEPA. The target hazard quotient (THQ) was >1 for Cd and Pb, whereas <1 for As. The study shows that tomato has good potential as Cd and Pb phytoremediator, hence must not be consumed when grown on Cd or Pb contaminated sites.     

Sources and Ecological Risk Assessment of Heavy Metal(loid)s in Agricultural Soils of Huzhou,China

To identify sources of heavy metal(loid) (HM) contamination in agricultural soils of Huzhou, surface soil samples were sampled from 89 different agricultural regions in 2012. Concentrations of heavy metal(loid)s, along with pH, total phosphorus (TP), total nitrogen (TN), and soil organic matter (SOM), were determined. Ecological risk was then assessed using a modified Hakanson ecological risk index, and the sources of contamination were determined using principal component analysis (PCA). Mean concentrations of heavy metal(loid)s were 10.26, 23.21, 83.75, 22.81, 0.25, 61.86, 33.03, and 0.15 mg kg^?1 for As, Cu, Zn, Ni, Cd, Cr, Pb, and Hg, respectively. Cu, Zn, Ni, Cr, Cd, Hg, and Pb were correlated positively with TP and there were obvious positive correlations among Cu, Zn, Ni, Cr, and Cd. Risk index (RI) values varied from 39 to 1246 with a mean value of 137. Enrichment of Pb, Zn, Cu, and especially Cd can be attributed to excessive use of nitrogen and phosphorus fertilizers containing heavy metals, as well to surface irrigation and natural soil formation. While the ecological risk of most agricultural soils in Huzhou is low, it is recommended that the use of phosphate and nitrogen fertilizers be restricted and production technology be improved to reduce the heavy metal(loid) concentrations. Results suggest that the Chinese environmental quality standard for soil should be revised to better address heavy metal(loid) contamination.     

改良剂对酸性土壤上伴矿景天铝毒缓解作用及镉锌吸收性的影响

为探究不同改良剂对酸性土壤铝(Al)胁迫条件下镉(Cd)锌(Zn)超积累植物伴矿景天Sedum plumbizincicola生长以及镉和锌吸取修复效率的影响,分别添加不同种类改良剂(钙镁磷肥(CMP)、MgCO3、KH2PO4)和不同浓度CMP进行温室盆栽试验。结果表明,CMP能够一定程度上提高土壤pH值并降低土壤交换性Al的浓度,MgCO3能够显著提高土壤pH值和降低土壤交换性Al的浓度,KH2PO4能够降低土壤中交换性Al浓度但未改变土壤pH值。施用适量的CMP(9.39 mg/kg)能够提高伴矿景天生物量和Cd、Zn吸取修复效率,用量过高会抑制伴矿景天生长和Cd、Zn修复效率;施用MgCO3可增大伴矿景天生物量和Cd、Zn修复效率,施用KH2PO4反而抑制了伴矿景天生长。酸性土壤上施用适量的CMP和MgCO3能够缓解伴矿景天的铝毒作用,维持较高的重金属吸收效率。     

Heavy metals extraction from municipal solid waste incineration fly ash using adapted metal tolerant Aspergillus niger

This study focused on the adaptation of Aspergillus niger tolerating high concentration of heavy metals for bioleaching of fly ash. The Plackett-Burman design indicated that Al and Fe inhibited the growth of A. niger (AS 3.879 and AS 3.40) significantly. The single metal (Al and Fe) and multi-metals adapted AS 3.879 strain tolerated up to 3500 mg/L Al, 700 mg/L Fe, and 3208.1mg/L multi-metals, respectively. The order of metal extraction yield in two-step bioleaching of 60 and 70 g/L fly ash using Al adapted, multi-metals adapted and un-adapted AS 3.879 strains was as follows: multi-metals adapted>Al adapted>un-adapted. The multi-metals adapted strain grew with up to 70 g/L fly ash and secreted 256 mmol/L organic acids after 288 h, where 87.4% Cd, 64.8% Mn, 49.4% Zn and 45.9% Pb were dissolved. The extracted metals in TCLP test of the bioleached fly ash by multi-metals adapted strain were under the regulated levels in China.     

Accumulation of Trace Metals by Mangrove Plants in Indian Sundarban Wetland: Prospects for Phytoremediation

The work investigates on the potential of ten mangrove species for absorption, accumulation and partitioning of trace metal(loid)s in individual plant tissues (leaves, bark and root/pneumatophore) at two study sites of Indian Sundarban Wetland. The metal(loid) concentration in host sediments and their geochemical characteristics were also considered. Mangrove sediments showed unique potential in many- fold increase for most metal(loid)s than plant tissues due to their inherent physicochemical properties. The ranges of concentration of trace metal(loid)s for As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb and Zn in plant tissue were 0.006–0.31, 0.02–2.97, 0.10–4.80, 0.13–6.49, 4.46–48.30, 9.2–938.1, 0.02–0.13, 9.8–1726, 11–5.41, 0.04–7.64, 3.81–52.20 μg g ^?1respectively. The bio- concentration factor (BCF) showed its maximum value (15.5) in Excoecaria agallocha for Cd, suggesting that it can be considered as a high-efficient plant for heavy metal bioaccumulation. Among all metals, Cd and Zn were highly bioaccumulated in E. agallocha (2.97 and 52.2 μg g ^?1 respectively. Our findings suggest that the species may be classified as efficient metal trap for Cd in aerial parts, as indicated by higher metal accumulation in the leaves combined with BCF and translocation factor (TF) values.     

Biosorption behavior of heavy metals in bioleaching process of MSWI fly ash by Aspergillus niger

In this study, it was considered that the biosorption of heavy metals by biomass might occur during the bioleaching of fly ash. This work is focused on the biosorption behavior of Al, Fe, Pb and Zn by Aspergillus niger during the bioleaching process. The fungal biomass was contacted with heavy metals solution which extracted from fly ash by using gluconic acid as leaching agent. The equilibrium time for biosorption was about 120 min. The biosorption experiment data at initial pH 6.5 was used to fit the biosorption kinetics and isotherm models. The results indicated that the biosorption of Al, Fe and Zn by A. niger biomass were well described by the pseudo-first order kinetic model. The pseudo-second order kinetic model was more suitable for that of Pb. The Langmuir isotherm model could well describe the biosorption of Fe, Pb and Zn while the Freundlich model could well describe the biosorption of Al. Furthermore, the biosorption of metal ions decreased evidently in the presence of fly ash as compared to that in the absence of fly ash. This research showed that although the biomass sorption occurred during the bioleaching process, it did not inhibit the removal of Al, Fe, Pb and Zn evidently from fly ash.     

Evaluation of metal mobility/immobility in fly ash induced by bacterial strains isolated from the rhizospheric zone of Typha latifolia growing on fly ash dumps

In this investigation, 11 bacterial strains were isolated from the rhizospheric zone of Typha latifolia. All the strains were aerobic, showed positive result with indole production and were able to grow in MacConkey agar. However, four strains were gram positive and others gram negative. These strains were inoculated separately in the fly ash with additional source of carbon to test their ability to increase the bioavailability or immobilization of toxic metals like Cu, Zn, Pb, Cd and Mn. It was observed that most of the bacterial strains either enhanced the mobility of Zn, Fe and Mn or immobilized Cu and Cd. However, there were a few exceptions. For example, in contrast to other bacterial strains, NBRFT6 enhanced immobility of Zn and Fe and NBRFT2 of Mn. On the other hand, in place of immobility induced by most of the bacterial strains, NBRFT8 and NBRFT9 enhanced bioavailability of Cu. However, in case of Cd, all the strains without any exception immobilized this metal. The results also indicated that the mobility/immobility of trace metals from the exchangeable fractions was the specific function of bacterial strains depending upon the several edaphic and environmental factors. Based on the extractability of metals from fly ash, a consortium of high performer bacterial strains will be further used to enhance the phytoextraction of metals from fly ash by metal accumulating plants. On the other hand, bacterial strains responsible for immobilization of metals may be used for arresting their leaching to water bodies.     

Leaching potential of heavy metals (Cd, Ni, Pb, Cu and Zn) from acidic sandy soil amended with dolomite phosphate rock (DPR) fertilizers

There is an increasing concern on heavy metal leaching from the soils amended with sewage sludge. A column study was conducted to examine the extent of leaching of five important heavy metals (Cd, Ni, Pb, Cu and Zn) from an acidic sandy soil amended with different dolomite phosphate rock (DPR) fertilizers (an application rate of 1% fertilizers) developed from DPR and N-Viro (consisting of biosolids and fly ash) at 0%, 10%, 20%, 30%, 40%, 50% and 100% DPR. Ten leaching events were carried out with each event done at an interval of 7 days and with total leaching volume of 1183mm, which is equivalent to the mean annual rainfall of this region during the period of 2001-2003. Leachate was collected after each leaching event and analyzed for heavy metals. The maximum leachate concentrations of Cd, Ni, Pb, Cu and Zn were all below drinking water quality guidance limits set by Florida Department of Environmental Protection and World Health Organization, suggesting that the application of DPR fertilizers may not pose a threat to water quality by leaching. Most of leachate concentrations of Cd, Ni and Pb were below their detection limits and there were no significant differences between the control and the treatments with different DPR fertilizers. By contrast, there were higher leachate concentrations of Cu and Zn (ranging from 0.7 to 37.1mug Cu/l and 5.1 to 205.6mug Zn/l for all treatments) due to their higher contents in both the soil and different DPR fertilizers compared with Cd, Ni and Pb. The leachate concentrations of Cu and Zn for each treatment decreased with increasing leaching events. The differences in leachate concentrations of Cu and Zn between the control and the treatments with different DPR fertilizers containing N-Viro were significant, especially in the first several leaching events and, moreover, they increased with increasing proportion of N-Viro in the DPR fertilizers. There were similar trends in total losses of Cu and Zn after ten leaching events. Greater differences in both leachate concentrations and total losses of Zn between the control and the treatments containing N-Viro were noted. Total losses of Zn for the treatments containing N-Viro were 3.0-5.1 times higher than those for the control compared with 1.4-2.2 times higher for total losses of Cu, suggesting that greater proportions of Zn losses came from the DPR fertilizers due to the greater mobility of Zn in the DPR fertilizers compared with Cu.