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。     

草酸青霉BZH-2002产果胶酶特性研究

对草酸青霉菌（Penixillium oxalicum）BZH-2002菌株固体发酵果胶酶的特性及浸提条件进行了研究,确定其最佳产酶时期为72—92h,利用干物质量最快的时期为24—72h发酵产酶期间培养基介质中pH值呈“V”字形变化。该菌株以甜菜渣、葵花盘为碳源,以（NH）2SO4为氮源时产酶率最高,分别高达4．33万和4．56万U／g干物质,（NH4）2SO4最佳用量0．9g/10g甜菜渣。此外,浸提方法对果胶酶产率也有一定影响,1％NaCl作为浸提液的效果最好,最佳浸提时间1h,浸提温度25—40℃。     

响应面法优化毒三素链霉菌中利普司他汀的提取工艺

采用响应面法对毒三素链霉菌提取工艺进行优化。首先确立乙醇为最佳的溶剂。以利普司他汀提取收率为指标,以乙醇为浸提溶剂,对料液比、乙醇体积分数、浸提时间、浸提温度和浸提次数进行单因素实验。在此基础上,选取料液比、乙醇体积分数、浸提时间为自变量,采用Box-Behnken设计的方法,研究各自变量及其交互作用对利普司他汀提取收率的影响。结果表明:毒三素链霉菌中利普司他汀的最佳提取工艺条件为液料比6.32∶1 m L/g、乙醇体积分数95%、浸提时间3.61 h。在此条件下,利普司他汀提取收率的预测值为83.35%,实验验证值为84.50%,相对误差为1.36%。     

牛樟芝固态发酵菌丝体三萜及多糖提取工艺优化研究

为研究牛樟芝固态发酵菌丝体中三萜和多糖的最佳提取工艺，选取浸提时间、料液比和提取温度3个因素，分别设置3个水平，以三萜和多糖得率为指标，并采用正交试验法进行分析。结果表明，三萜的最佳提取工艺条件为：浸提时间3 h、料液比1∶30 (g·mL-1)、温度70 ℃，在此条件下，得率为3.43%；多糖的最佳提取工艺为：浸提时间2 h、料液比1∶20 (g·mL-1)、温度95 ℃，在此条件下得率为4.71%。研究结果为牛樟芝固态发酵菌丝体中三萜和多糖的提取工艺提供了参考。     

恩施碎米荠硒多糖提取条件的研究

为了探索恩施碎米荠多糖的最佳提取条件,以干制碎米荠粉末为试验材料,以双蒸水为浸提剂,在浸提温度、时间、浸取剂的用量、提取次数和pH等单因素试验的基础上,进行了四元二次通用旋转组合试验.试验结果表明,1g碎米荠干粉,浸提温度90℃、浸提时间3 h-3.5 h、浸取剂的用量30mL、提取次数4～5次和浸提液的pH值为9是多糖适宜的提取条件.     

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。     

萌发大麦种子水溶性蛋白组分提取

采用二次回归正交旋转组合试验方法,对大麦种子中水溶性蛋白组分的提取工艺进行了研究,得出了大麦种子水溶蛋白组分提取量与料液浓度,浸提温度和浸提时间的数学模型,确定了大麦籽粒水溶蛋白组分最佳提取条件为料液浓度9．1％,浸提温度20℃,浸提时间3h;通过连续检测萌发大麦种子水溶蛋白含量发现：随萌发时间增长,蛋白含量逐渐升高,麦芽中水溶蛋白含量约为大麦的4倍．     

正交设计优化裂褶菌发酵全液多糖提取工艺

采用正交设计试验方法进行了裂褶菌发酵全液中裂褶菌多糖的提取工艺优化的研究。结果表明:影响多糖提取的因素依次是料水比>浸提温度>浸提时间,三个因素的最佳组合是A4B2C3,即料水比为1∶3,浸提温度为80℃,浸提时间为4 h。在此条件下,发酵全液中多糖的最大得率达到3.65 g/L。     

正交实验法优化黄柏中黄连素的酶碱法提取工艺

为了提高黄柏中黄连素的提取得率与效率,采用传统方法碱提法与酶解辅助提取相结合来优化黄柏中黄连素的提取工艺。以黄连素浸提率为评价指标,考察纤维素酶浓度、酶解时间、料液比及浸提时间对提取效率的影响。在单因素实验的基础上,通过正交实验分析各因素的作用大小以及它们之间的交互作用。优选出黄柏中黄连素的酶碱法提取最佳工艺条件为:纤维素酶浓度15‰、酶解时间1 h、料液比1∶7、浸提时间7 h,在该条件下黄连素的浸提率可达8.99%。该提取工艺浸提率高,成本低,稳定性好,可用于生产上黄柏中黄连素的提取。     

土壤重金属污染对蚯蚓的急性毒性效应研究

测定了草甸棕壤条件下 ,Cu、Zn、Pb、Cd单一 /复合污染对蚯蚓的急性致死及亚致死效应 .结果表明 ,Cu、Pb浓度与蚯蚓死亡率显著相关 (α=0 .0 5 ,RCu=0 .86 ,RPb=0 .87) ,Cu浓度与生长抑制率显著相关 (α=0 .0 5 ,RCu=0 .84) ,其他供试重金属浓度与蚯蚓死亡率和生长抑制率相关性不显著 .蚯蚓个体对重金属毒性的耐受程度差别较大 .其毒性阈值 (引起个体蚯蚓死亡浓度 )分别为 :Cu 30 0mg·kg-1,Zn 130 0mg·kg-1,Pb 170 0mg·kg-1,Cd 30 0mg·kg-1.LC50 分别为 :Cu 40 0～ 45 0mg·kg-1,Zn15 0 0～ 190 0mg·kg-1,Pb2 35 0～ 2 40 0mg·kg-1,Cd 90 0mg·kg-1.在Cu、Zn、Pb、Cd单一污染引起 >10 %蚯蚓死亡的浓度下 ,复合污染导致 10 0 %蚯蚓死亡 ,表明复合污染极强的协同效应 .     

重金属污染土壤毒性的斜生栅藻生长抑制实验诊断

应用斜生栅藻 (Scenedesmusobliquus)对重金属污染土壤的毒性进行诊断 ,结果表明 ,斜生栅藻的增长率与土壤中的重金属含量明显相关 ,并且随重金属投加量的增加 ,其增长率逐渐降低 .对两种测试参数进行比较 ,发现采用细胞数增长率作为土壤毒性的检测指标要比采用光密度增长率更为敏感 .当采用细胞数增长率作为检测指标时 ,4种重金属的EC50 顺序为 :Pb >Cu >Zn >Cd ;采用光密度增长率作为检测指标时 ,4种重金属的EC50 顺序为 :Pb >Cu >Cd >Zn .复合污染情况下 ,由于金属间的协同作用 ,使土壤的毒性比单一重金属污染时有明显增强 ,从而为污染土壤的优先修复提供了理论依据     

Bio-Acidification and Leaching of Metals,Nitrogen, and Phosphorus from Soil and Sludge Mixtures

Soil and wastewater treatment sludge are commonly brought together in mixtures for a variety of beneficial purposes. The mixtures contain bioacidifying (i.e., sulfur-oxidizing) microorganisms that can easily be activated through providing the appropriate substrate and environmental conditions. In this study, contaminated soil and sludge mixtures were subjected to controlled bio-acidification and the impacts of the process on the partitioning of heavy metals, nitrogen, and phosphorus were examined. Three successive bio-acidification cycles resulted in significant leaching of metals from sludge. The leaching results, expressed as fraction of total mass of metals in the sludge, averaged 67% for Cr, 96% for Ni, 24% for Zn; 16% for Cu; 23% for Cd; and 96% for Pb. Bio-acidification of the sludge also converted 28 to 45% of the organic nitrogen into ammonia and increased the soluble orthophosphates fraction of total phosphorus by approximately 18 to 20%. Bio-acidification also resulted in significant metals leaching from the contaminated soils in the soil/sludge mixtures. Soil/sludge mixtures were prepared using six soil particle sizes (less than 0.075?mm to 2.38?mm) contaminated with 22,500?mg/kg Zn, 14,000?mg/kg Pb, 1500?mg/kg Cr, 9500?mg/kg Cu, 1000?mg/kg Ni, and 1000?mg/kg Cd. The addition of metals to the soil inhibited the sulfur-oxidizing microorganisms, preventing bio-acidification in the mixtures containing 4 to 50?g soil in 130?ml sludge, and considerably slowing bio-acidification in the mixtures containing 1 to 3?g soil. Using a mixture that contained 2-g soil samples, three successive bio-acidification cycles resulted in significant cumulative metals leaching results. The leaching results, expressed as percentage of the mass of metals added to the soil, were in the range of 56 to 98% for Cr, 77 to 95% for Zn, 33 to 66% for Ni, 64 to 82% for Cu, and 10 to 33% for Pb, with the higher results in each range belonging to the larger size soil particles. On the other hand, only Cr was leached in neutralized soil samples. The results confirmed the potential for inhibition of the sulfur-oxidizing microorganisms and bio-acidification in contaminated soil/sludge mixtures, and the significant impacts of bio-acidification on the mobility of metals, nitrogen, and phosphorus. In addition, the results confirmed the potential for using controlled bioacidification for removing heavy metals from contaminated soil using the indigenous sulfur oxidizing microorganisms in sludge.     

Leaching Behavior of Heavy Metals and Transformation of Their Speciation in Polluted Soil Receiving Simulated Acid Rain

Heavy metals that leach from contaminated soils under acid rain are of increasing concern. In this study, simulated acid rain (SAR) was pumped through columns of artificially contaminated purple soil. Column leaching tests and sequential extraction were conducted for the heavy metals Cu, Pb, Cd, and Zn to determine the extent of their leaching as well as to examine the transformation of their speciation in the artificially contaminated soil columns. Results showed that the maximum leachate concentrations of Cu, Pb, Cd, and Zn were less than those specified in the Chinese Quality Standards for Groundwater (Grade IV), thereby suggesting that the heavy metals that leached from the polluted purple soil receiving acid rain may not pose as risks to water quality. Most of the Pb and Cd leachate concentrations were below their detection limits. By contrast, higher Cu and Zn leachate concentrations were found because they were released by the soil in larger amounts as compared with those of Pb and Cd. The differences in the Cu and Zn leachate concentrations between the controls (SAR at pH 5.6) and the treatments (SAR at pH 3.0 and 4.5) were significant. Similar trends were observed in the total leached amounts of Cu and Zn. The proportions of Cu, Pb, Cd, and Zn in the EXC and OX fractions were generally increased after the leaching experiment at three pH levels, whereas those of the RES, OM, and CAR fractions were slightly decreased. Acid rain favors the leaching of heavy metals from the contaminated purple soil and makes the heavy metal fractions become more labile. Moreover, a pH decrease from 5.6 to 3.0 significantly enhanced such effects.     

In-Situ Remediation of Lead–Zinc Polymetallic Mine Contaminated Soils by MnFe2O4 Microparticles

In-situ remediation is a practical approach to remediate soils contaminated with heavy metals. The MnFe₂O₄ microparticles (MM) were prepared for the in-situ remediation of contaminated soils from a lead–zinc polymetallic mine in Inner Mongolia province, China. The effects of MM dosage, pH on remediation efficiency, were determined with static vibration leaching experiment, and the release risk of heavy metals of treated soil was studied by column leaching experiment. The results showed that the leached Cu, Pb, Zn, and As concentration decreased drastically with increasing MM dosage, when the dosage was lower than 10 g/kg. Moreover, the decrease of pH caused increase of leached concentration of Cu, Pb, Zn, but slight decrease of leached As concentration. For the amended soil, concentrations of leached heavy metals were lower than Grade III limit of Chinese Environmental Quality Standards for Ground and Surface water (GB3838-2002) under simulated acid rain leaching condition. In comparison with non-amended soils, the total amount of Cu, Pb, Zn, and As release from amended soils was reduced by 93.6%, 69.2%, 57.0%, and 99.7%, respectively. The MM is a kind of promising amendment for heavy metals contaminated soil.     

黔西北土法炼锌废弃地植被重建的限制因子

以土法炼锌废弃地的废渣、污染土壤和背景土壤为基质材料,分别种植黑麦草(Lolium perenne)和三叶草(Trifolium pretense),分析各种基质的基本化学特性、重金属(Pb、Zn、Cd)含量及其赋存形态、两种植物生长特性.结果表明,土法炼锌废渣上植被重建的主要限制因子包括高盐碱胁迫、有机质含量低、养分缺乏(TN、碱解N、TK).废渣重金属含量高,有效态含量低,对植物毒性小,但存在潜在危害性.污染土壤重金属含量低于废渣,但生物有效态重金属含量高.污染土壤植被重建的限制因子包括重金属毒性、P和K的有效性.废渣与污染土壤混合是土法炼锌废弃地基质改良的有效途径.     

The performance of vetivers (Chrysopogon zizaniodes and Chrysopogon nemoralis) on heavy metals phytoremediation: laboratory investigation

Abstract

Phytoremediation with vetiver was investigated in relation to heavy metal contaminated soil in Thailand. The work compared the performance of two species of vetiver named Songkhla 3 (Chrysopogon zizaniodes) and Prachuap Khiri Khan (Chrysopogon nemoralis) in absorbing lead, zinc, and cadmium in contaminated soils. Toxicity Characteristic Leaching Procedure (TCLP), and Allium tests were conducted to determine toxicity of treated soil. Ethylenediaminetetraacetic acid (EDTA) was also used to increase heavy metals concentration in solution in soil, which led to an increase in translocation and bioaccumulation factors. In general, results showed that concentration of heavy metals decreased in soil and increased in both the shoots and roots of vetivers during a 4-month treatment period. TCLP results indicated that the concentration of zinc and cadmium in contaminated soil was reduced over treatment time, and significantly increased after EDTA was applied. To confirm vetiver performance in phytoremediation, Allium testing showed that remained heavy metals in treated soils had no effect on nucleus aberration. Songkhla 3 and Prachuap Khiri Khan showed similar trends in their ability to remediate lead, zinc, and cadmium from contaminated soil. Both species could accumulate higher concentrations of heavy metals in their shoots and roots over time, and with EDTA application.     

Assessment of a heavy metals‐contaminated site using sequential extraction,TCLP, and risk assessment techniques

The mobility of selected heavy metals in contaminated soil at a previous industrial site in Brisbane, Australia, was assessed using a sequential extraction technique. Copper, Pb, Zn, Cr, Fe, and Mn were extracted from the soil solution/exchangeable, carbonate, Fe and Mn oxides, and organic matter fractions. The amounts of metals adsorbed by these fractions were used as an indicator of each metal's mobility in the soil. Copper and Pb were largely adsorbed by the organic and oxide fractions, while a significant amount of Zn was extracted from the carbonate fraction. The potential mobility and biological availability of the metals in these soils is Zn > Cr = Cu ≈ Pb. Soils were also analyzed using the toxicity characteristic leaching procedure (TCLP) to determine whether the contaminated soil could be disposed of by landfilling. The leachability of all metals from the soils was very low, with metal concentrations below the allowable limits. The TCLP also showed that Zn was the most mobile metal in these soils. An environmental and health risk assessment was undertaken, and it was concluded that the site did not represent a risk despite the “total”; concentrations of some metals being up to 40 times the investigation threshold value adopted in Australia.     

Selenium and sulfur accumulation and soil selenium dissipation in planting of four herbaceous plant species in soil contaminated with drainage sediment rich in both selenium and sulfur

Four selenium (Se) nonaccumulator plant species, including a forage grass species, Tall Fescue (Festuca arundinacea Schreb.), a forage legume species, Alfalfa (Medicago sativa L.), a wetland species, Rush (Juncus tenuis Wild.), and a dry-land alkaline soil species, Saltgrass (Distichlis spicata L.), were grown in soil contaminated by agricultural drainage sediment having elevated levels of Se and sulfur (S). The above-ground plant tissues were consecutively harvested five times and examined for Se and S accumulation. Plant tissue Se concentrations ranged from 23.0 mg kg-1 to 8.3 mg kg-1. Tissue S concentrations ranged from 3239 mg kg-1 to 7034 mg kg-1. Both tissue Se and S concentrations were significantly different between harvests, species, and species/harvest interactions. Total Se accumulation by the plant biomass harvested ranged from 0.3 to 1.3 mg per soil column and total S accumulations ranged from 87.5 to 321.1 mg per soil column. The reduction in the percentage of total soil Se after 24 weeks growth of the plant species ranged from 12.0% in the Tall Fescue planting to 17.3% in the Rush planting. Over 90% of the soil Se losses were unidentified losses and leaching of Se was prevented. The accumulations of Se and S in the plant biomass were very small compared with the total soil Se and S losses, but substantial amounts of total soil Se (12.0 to 15.0%) and S (28.0 to 50.9%) inventories were dissipated by the growing and harvesting of the plants. The soil S concentration was several hundred times higher than the soil Se concentration, but Se accumulation by the plants and Se dissipation from the soil were not impaired by the high level of soil sulfur. For natural grassland habitat restoration, such as at the Kesterson Wildlife Refuge in the Central Valley of California, or for restoration of large-scale Se contaminated agricultural lands, Se nonaccumulator plant species are favorable candidates, because the possibility of introducing Se toxicity into the food chain can be minimized.     

The Chemophytostabilisation Process of Heavy Metal Polluted Soil

Industrial areas are characterised by soil degradation processes that are related primarily to the deposition of heavy metals. Areas contaminated with metals are a serious source of risk due to secondary pollutant emissions and metal leaching and migration in the soil profile and into the groundwater. Consequently, the optimal solution for these areas is to apply methods of remediation that create conditions for the restoration of plant cover and ensure the protection of groundwater against pollution. Remediation activities that are applied to large-scale areas contaminated with heavy metals should mainly focus on decreasing the degree of metal mobility in the soil profile and metal bioavailability to levels that are not phytotoxic. Chemophytostabilisation is a process in which soil amendments and plants are used to immobilise metals. The main objective of this research was to investigate the effects of different doses of organic amendments (after aerobic sewage sludge digestion in the food industry) and inorganic amendments (lime, superphosphate, and potassium phosphate) on changes in the metals fractions in soils contaminated with Cd, Pb and Zn during phytostabilisation. In this study, the contaminated soil was amended with sewage sludge and inorganic amendments and seeded with grass (tall fescue) to increase the degree of immobilisation of the studied metals. The contaminated soil was collected from the area surrounding a zinc smelter in the Silesia region of Poland (pH 5.5, Cd 12 mg kg^-1, Pb 1100 mg kg^-1, Zn 700 mg kg^-1). A plant growth experiment was conducted in a growth chamber for 5 months. Before and after plant growth, soil subsamples were subjected to chemical and physical analyses. To determine the fractions of the elements, a sequential extraction method was used according to Zeien and Brümmer. Research confirmed that the most important impacts on the Zn, Cd and Pb fractions included the combined application of sewage sludge from the food industry and the addition of lime and potassium phosphate. Certain doses of inorganic additives decreased the easily exchangeable fraction from 50% to 1%. The addition of sewage sludge caused a decrease in fraction I for Cd and Pb. In combination with the use of inorganic additives, a mobile fraction was not detected and an easily mobilisable fraction was reduced by half. For certain combinations of metals, the concentrations were detected up to a few percent. The application of sewage sludge resulted in a slight decrease in a mobile (water soluble and easily exchangeable metals) fraction of Zn, but when inorganic additives were applied, this fraction was not detected. The highest degree of immobilisation of the tested heavy metals relative to the control was achieved when using both sewage sludge and inorganic additives at an experimentally determined dose. The sequential extraction results confirmed this result. In addition, the results proved that the use of the phytostabilisation process on contaminated soils should be supported.