塔什库尔干县土壤可培养细菌多样性及其胞外酶检测

对新疆塔什库尔干县土壤中可培养细菌多样性进行分析，以期初步阐明该地区土壤可培养细菌群落结构。采用5种琼脂培养基分离纯化可培养细菌，依据其16S rRNA基因序列进行系统发育分析，并运用平板法对纯化菌株的胞外酶产生情况进行检测。序列分析结果表明，33株细菌分别属于放线菌门（96.97%）和厚壁菌门（3.03%）等2个大的系统发育类群，5个属14个种。其中节杆菌属（48.48%）和假节杆菌属（24.24%）为优势菌属。培养基优势度指数结果显示，高氏1号培养基的优势度指数最高，菌株分离效果最好。分离菌株产胞外酶结果显示，33株细菌中含有至少1种胞外酶活性的菌株共19株（57.58%）。总体上，塔什库尔干县土壤中可培养细菌多样性较单一，细菌产单一种类胞外酶活性比例较高，分离菌株可为塔什库尔干县微生物资源的开发和利用提供前期基础。     

4株苯磺隆降解菌的分离鉴定及其生长特性

从长期受农药苯磺隆污染的土壤中通过采用富集培养分离技术得到4株以苯磺隆为唯一碳源生长的细菌,分别将其命名为B1、B2、B3和B4。通过观察这4种菌株的形态学特征,研究其生理生化特性以及分析其16S rDNA序列,初步鉴定菌株B1为铜绿假单胞菌（Pseudomonas aeruginosa）,B2为戴尔福特菌（Delftia sp.）,B3为微杆菌（Microbacterium sp.）,B4为产碱杆菌（Alcaligenes sp.）。并通过研究温度、初始pH值、接种量、苯磺隆初始浓度、培养基体积、氮源、碳源、Mg^2＋浓度等因素对4种菌株生长情况的影响,确定了菌株的最佳生长条件。结果显示,B1菌株的最适温度为35℃,其他3株菌株均为30℃。菌株B3最适pH为8.0,其余3株菌株均为pH7.0。B1和B3菌株最适接种量为15%,B2和B4最适接种量为10%。菌株B3最适苯磺隆初始浓度为100mg·L^-1,其余菌株最适苯磺隆初始浓度均为200mg·L^-1。4株菌株最适培养基体积均为75mL,最适氮源均为硝酸铵,最适碳源均为葡萄糖。B2菌株最适Mg^2＋浓度为100mg·L^-1,其余3株菌株均为200mg·L^-1。B1和B4菌株最适NaCl浓度为20g·L^-1,B2菌株NaCl浓度为5-30g·L^-1,B3菌株最适NaCl浓度为50g·L^-1。该结果为利用微生物对农药苯磺隆污染的土壤进行原位生物修复提供理论依据。     

勿色杆菌和假单胞菌对原油降解特征对比

为对比勿色杆属菌种(Achromobater sp)SLTHX114株和黄色假单胞菌(Pseudomonas flavescens)SLTHX214株对原油降解特征的差异性,在40℃恒温有氧实验室条件下,使用两株原油降解菌对塔里木油田原油进行了生物降解模拟实验,分析了生物降解气组分、生物降解原油的族组分及生物标志化合物变化特征。实验结果表明,革兰氏阴性SLTHX214株对原油降解能力强于革兰氏阳性SLTHX114株,SLTHX114株对原油中的饱和烃具有明显的降解作用,而SLTHX214株更倾向于降解原油中的芳烃。对土壤石油污染修复和菌种选择具有一定的指示意义。     

工农业副产物添加对棕壤的改良研究

由于不当农艺措施等人为因素影响,辽宁省棕壤区土壤发生酸化,需要添加改良剂予以阻控。以农田棕壤为研究对象,选取工业矿渣（煤矸石和膨润土矿渣）、秸秆（玉米秸秆、花生秸秆）、菌糠（平菇菌糠、金针菇菌糠）等6种常见的工农业生产副产物作为改良剂,采用室内恒温培养的方法,考察了工农业生产副产物对酸化棕壤的影响。结果表明：添加秸秆、菌糠和工业废弃物均可一定程度上改良土壤的酸度,使土壤pH提高0.29～0.79个单位;添加改良剂可不同程度改变土壤净硝化作用,但影响不大;改良剂的添加有效增强了土壤磷酸酶、蔗糖酶、过氧化氢酶活性。综合而言,农业生产副产物更适合酸化棕壤的改良。     

川西北高寒草地沙化土壤特征及治理模式探讨——以阿坝州红原县为例

通过对川西北高寒草地不同类型的沙化样地0—10cm,10～20cm和20～30cm土壤有机质、pH和含水量进行分析。结果表明：（1）随着沙化程度加重,土壤有机质含量和土壤含水量明显降低;（2）随着土层深度增加,土壤有机质含量降低;未沙化、轻度沙化样地的土壤含水量随土层深度增加而降低,重度沙化样地则相反;（3）中度和重度沙化样地土壤pH约7．0,未沙化和轻度沙化pH值在6．5左右;沙地土壤有机质与pH值呈显著负相关关系,沙化土壤有机碳与水分损失是一个正反馈。鉴于川西高寒草地特殊环境,探讨了选用适宜的多年生高原药用植物或者其他高价值资源植物作为固沙材料,将治沙与经济发展相结合,建立高寒沙化草地治理模式。     

产菊粉酶细菌菌株的筛选及菌种鉴定

从山东威海沿海滩涂菊芋生长的根际土壤中分离得到能产菊粉酶的菌株20株,经过进一步摇瓶复筛,获得了产菊粉酶活力较高的一株细菌F1,其发酵液酶活达到1.73U/mL。通过形态学观察、16SrDNA序列分析及生理生化研究,鉴定该菌为芽孢杆菌属的巨大芽孢杆菌(bacillus megaterium)。     

不同pH值、不同比例的添加剂对土壤吸附铯的影响

铯极易被粘土矿物和有机质吸附而且不易解吸,在示踪水土侵蚀、处置核废物方面有着积极的作用。不同的pH值、不同比例的添加剂都会影响土壤对核素铯的吸附,实验证明两种土壤对核素铯的吸附在pH=4～7时很大,pH=7时达到最大;四种添加剂粗沸石、人造沸石、Ca（OH）2、MnO2只有粗沸石的加入量与铯的吸附比成正相关关系,可以提高土壤对铯的吸附能力。     

微生物法处理海上钻井废钻井液

微生物法适用于海上钻井含油废弃物的处理。通过多次对菌株采集、分离、纯化和培养驯化,选育得到了3株对石油烃类有很好降解效果的石油类降解菌;确定了石油类降解菌适宜的生化处理条件:最佳生长及原油降解温度为50℃、最佳生长及原油降解酸碱性环境为pH=6.0、最佳菌株接种量2%、最佳原油初始浓度为500mg/L。处理后的含油废弃钻井液含油量基本稳定在2mg/L以下,降解率达98%以上。     

骨炭＋沸石对重金属污染土壤的修复效果及评价

采用盆栽试验,研究了铜铅镉复合污染土壤添加骨炭和沸石前后对土壤pH值、土壤中重金属有效态含量、蕹菜生长、重金属吸收量的影响。结果表明,土壤污染后pH值显著降低,土壤中重金属有效态含量显著增加,蕹菜生长不良,株高、鲜重、干重显著降低,同时蕹菜重金属含量增加;添加固化剂后土壤pH值提高了2.21和2.29个单位,土壤有效态重金属含量显著降低,蕹菜株高、鲜重、干重增加,同时使轻度污染土壤上的蕹菜达到卫生安全标准。     

高效降解环己酮红球菌JDM-3-12的分离及其系统发育分析

从岳阳巴陵石化公司环己酮生产车间总出水口的污泥中筛选到一株环己酮降解菌株,菌号为JDM-3-12;该菌能以环己酮为唯一碳源且能忍受5000 mg/L的环己酮,当环己酮的质量浓度为2000 mg/L时,在温度为30℃,转速为150 r/m in,pH=7的条件下,72小时内该菌株对环己酮的降解率达到97.91%。通过形态观察、生理生化特征检测和基于16S rRNA基因序列的系统发育分析,初步鉴定其为赤红球菌(Rhodococcus ruber)中的一个菌株,该菌最适生长温度为35℃,最适生长pH 7。     

Influence of soil pH and application rate on the oxidation of calcium sulfite derived from flue gas desulfurization

Calcium sulfite hemihydrate (CaSO(3).0.5H2O), a common byproduct of coal-fired utilities, is fairly insoluble and can decompose to release toxic SO2 under highly acidic soil conditions; however, it can also oxidize to form gypsum. The objective of this study was to examine the effects of application rate and soil pH on the oxidation of calcium sulfite under laboratory conditions. Oxidation rates measured by release of SO4-S to solution decreased with increasing application rate. Leachate SO4-S from soils amended with 1.0 to 3.0 g kg-1 CaSO3 increased over a 21 to 28 d period before reaching a plateau. At 4 g kg-1, maximum SO4-S release was delayed until Week 7. Oxidation and release of SO4-S from soil amended with 3.0 g kg-1 calcium sulfite increased markedly with decreasing soil pH. After only 3 d incubation, the concentrations of SO4-S in aqueous leachates were 77, 122, 170, 220, and 229 mg L-1 for initial soil pH values of 7.8, 6.5, 5.5, 5.1, and 4.0, respectively. At an initial soil pH value of 4.0, oxidation/dissolution did not increase much after 3 d. At higher pH values, oxidation was maximized after 21 d. These results suggest that autumn surface applications of calcium sulfite in no-till systems should permit ample time for oxidation/dissolution reactions to occur without introducing biocidal effects related to oxygen scavenging. Soil and annual crops can thus benefit from additions of soluble Ca and SO4 if calcium sulfite is applied in advance of spring planting.     

Evaluating Cover Crops (Sudex,Sunn Hemp,Oats) for Use as Vegetative Filters to Control Sediment and Nutrient Loading From Agricultural Runoff in a Hawaiian Watershed1

Abstract: A study was conducted to determine the effects of three land covers (sunn hemp –Crotalaria juncea, sudex, a sorghum‐sudangrass hybrid –Sorghum bicolor x S. bicolor var. sudanese, and common oats –Avena sativa) planted as vegetative filter strips on the reduction of sediment and nutrient loading of surface runoff within the Kaika‐Waialua watershed on the island of Oahu, Hawaii. Runoff samples were collected and analyzed for total suspended solids (TSS), total dissolved solids (TDS), phosphorous, and three forms of nitrogen (nitrate, ammonium, total nitrogen). Study results show that during seven out of 10 runoff events, the three cover crop treatments significantly reduced TSS as compared to the fallow treatment. Average removal efficiencies were 85, 77, and 73% for oats, sunn hemp, and sudex, respectively, as compared to the fallow treatment. Nutrient concentrations were low with phosphorous concentrations, lower than 1 (μg/ml) for all treatments, and total nitrogen (TN) concentrations below 7 (μg/ml) except in the sunn hemp treatment, where TN concentrations were less than 10 (μg/ml). Results of analysis of TDS showed that the cover crop treatments did not decrease dissolved solids concentrations in comparison with the fallow treatment. Analysis of nutrient concentrations in runoff samples did not detect any significant decreases in phosphorous, nitrogen, ammonium, or TN concentrations in comparison to the fallow treatment. However, a significant increase in TN concentrations in the sunn hemp treatment was detected and showed the nitrogen fixing capacity of sunn hemp. No treatment effects on runoff volume were detected, and runoff volumes were directly correlated with rainfall amounts showing no crops significantly impacted soil infiltration rates. These results were attributed to extremely low soil hydraulic conductivities (0.0001‐7 cm/day at the soil surface, 15 and 30 cm below the soil surface). This study showed that cover crops planted as vegetative filters can effectively reduce sediment loads coming from idle and fallow fields on moderately steep volcanically derived highly weathered soils.     

我国南方主要酸沉降区临界负荷研究

以马尾松为指示植物,对韶关的土壤进行了长期淋溶模拟并记录其化学状态。结果发现,土壤溶液的pH值下降到4.0,Bs值下降到几乎为零,有较大量的A1离子溶出。最后选取土壤溶液pn〉4.0、KS〉10％和[Al^3＋]〈0.1mmol／L为临界化学指标,参考国内外应用广泛的MAGIC模型和SMART模型,确定韶关酸沉降临界负荷（S的临界负荷）为14.1keq／hm^2.a。     

球壳孢菌和胶孢炭疽菌的液体培养特性研究

对银杏叶内生真菌球壳孢科菌株A114和胶孢炭疽菌菌株05—27的液体培养特性的初步研究得出：两种菌株均在马铃薯葡萄糖液体培养基中生长最好、菌丝产量最高，在pH4．0-8．5的马丁氏液体培养基中均能生长。A114菌株和05—27菌株的最佳氮、碳源分别为酵母粉和葡萄糖，A114菌株最适pH为6．6，05—27菌株最适pH为6．9。     

Adsorption-desorption behavior of copper at contaminated levels in red soils from China

Adsorption-desorption of copper (Cu2+) at contaminated levels in two red soils was investigated. The red soil derived from the Quaternary red earths (clayey, kaolinitic thermic plinthite Aquult) (REQ) adsorbed more Cu2+ than the red soil developed on the Arenaceous rock (clayey, mixed siliceous thermic typic Dystrochrept) (RAR). The maximum adsorption values (M(A)) that are obtained from the simple Langmuir model were 25.90 and 20.17 mmol Cu2+ kg(-1) soil, respectively, for REQ and RAR. Adsorption of Cu2+ decreased soil pH, by 0.8 unit for the REQ soil and 0.6 unit for the RAR soil at the highest loadings. The number of protons released per Cu2+ adsorbed increased sigmoidally with increasing initial Cu2+ concentration for the RAR soil, but the relationship was almost linear for the REQ soil. The RAR soil released about 2.57 moles of proton per mole of Cu2+ adsorbed at the highest Cu2+ loading and the corresponding value for the REQ soil was 1.12. The distribution coefficient (Kd) decreased exponentially with increasing Cu2+ loading. Most of the adsorbed Cu2+ in the soils was readily desorbed in the NH4Ac. After five successive extractions with 1 mol L(-1) NH4Ac (p 5.0), 61 to 95% of the total adsorbed Cu2+ in the RAR soil was desorbed and the corresponding value for the REQ soil was 85 to 92%, indicating that the RAR soil had a greater affinity for Cu2+ than the REQ soil at low levels of adsorbed Cu2+.     

Carbon storage potential in natural fiber composites

The environmental performance of hemp based natural fiber mat thermoplastic (NMT) has been evaluated in this study by quantifying carbon storage potential and CO₂ emissions and comparing the results with commercially available glass fiber composites. Non-woven mats of hemp fiber and polypropylene matrix were used to make NMT samples by film-stacking method without using any binder aid. The results showed that hemp based NMT have compatible or even better strength properties as compared to conventional flax based thermoplastics. A value of 63 MPa for flexural strength is achieved at 64% fiber content by weight. Similarly, impact energy values (84–154 J/m) are also promising. The carbon sequestration and storage by hemp crop through photosynthesis is estimated by quantifying dry biomass of fibers based on one metric ton of NMT. A value of 325 kg carbon per metric ton of hemp based composite is estimated which can be stored by the product during its useful life. An extra 22% carbon storage can be achieved by increasing the compression ratio by 13% while maintaining same flexural strength. Further, net carbon sequestration by industrial hemp crop is estimated as 0.67 ton/h/year, which is compatible to all USA urban trees and very close to naturally, regenerated forests. A comparative life cycle analysis focused on non-renewable energy consumption of natural and glass fiber composites shows that a net saving of 50 000 MJ (3 ton CO₂ emissions) per ton of thermoplastic can be achieved by replacing 30% glass fiber reinforcement with 65% hemp fiber. It is further estimated that 3.07 million ton CO₂ emissions (4.3% of total USA industrial emissions) and 1.19 million m³ crude oil (1.0% of total Canadian oil consumption) can be saved by substituting 50% fiber glass plastics with natural fiber composites in North American auto applications. However, to compete with glass fiber effectively, further research is needed to improve natural fiber processing, interfacial bonding and control moisture sensitivity in longer run.     

Adsorption-desorption characteristics of mercury in paddy soils of China

Mercury (Hg) has received considerable attention because of its association with various human health problems. Adsorption-desorption behavior of Hg at contaminated levels in two paddy soils was investigated. The two representative soils for rice production in China, locally referred to as a yellowish red soil (YRS) and silty loam soil (SLS) and classified as Gleyi-Stagnic Anthrosols in FAO/UNESCO nomenclature, were respectively collected from Jiaxin County and Xiasha District of Hangzhou City, Zhejiang Province. The YRS adsorbed more Hg(2+) than the SLS. The characteristics of Hg adsorption could be described by the simple Langmuir adsorption equation (r2 = 0.999 and 0.999, P < 0.01, respectively, for the SLS and YRS). The maximum adsorption values (Xm) that were obtained from the simple Langmuir model were 111 and 213 mg Hg(2+) kg(-1) soil, respectively, for the SLS and YRS. Adsorption of Hg(2+) decreased soil pH by 0.75 unit for the SLS soil and 0.91 unit for the YRS soil at the highest loading. The distribution coefficient (kd) of Hg in the soil decreased exponentially with increasing Hg(2+) loading. After five successive desorptions with 0.01 mol L(-1) KCl solution (pH 5.4), 0 to 24.4% of the total adsorbed Hg(2+) in the SLS soil was desorbed and the corresponding value of the YRS soil was 0 to 14.4%, indicating that the SLS soil had a lower affinity for Hg(2+) than the YRS soil at the same Hg(2+) loading. Different mechanisms are likely involved in Hg(2+) adsorption-desorption at different levels of Hg(2+) loading and between the two soils.     

Dissolution of trace element contaminants from two coastal plain soils as affected by pH

Trace element mobility in soils depends on contaminant concentration, chemical speciation, water movement, and soil matrix properties such as mineralogy, pH, and redox potential. Our objective was to characterize trace element dissolution in response to acidification of soil samples from two abandoned incinerators in the North Carolina Coastal Plain. Trace element concentrations in 11 soil samples from both sites ranged from 2 to 46 mg Cu kg(-1), 3 to 105 mg Pb kg(-1), 1 to 102 mg Zn kg(-1), 3 to 11 mg Cr kg(-1), < 0.1 to 10 mg As kg(-1), and < 0.01 to 0.9 mg Cd kg(-1). Acidified CaCl2 solutions were passed through soil columns to bring the effluent solution to approximately pH 4 during a 280-h flow period. Maximum concentrations of dissolved Cu, Pb, and Zn at the lowest pH of an experiment (pH 3.8-4.1) were 0.32 mg Cu L(-1), 0.11 mg Pb L(-1), and 1.3 mg Zn L(-1) for samples from the site with well-drained soils, and 0.25 mg Cu L(-1), 1.2 mg Pb L(-1), and 1.4 mg Zn L(-1) for samples from the site with more poorly drained soils. Dissolved Cu concentration at pH 4 increased linearly with increasing soil Cu concentration, but no such relationship was found for Zn. Dissolved concentrations of other trace elements were below our analytical detection limits. Synchrotron X-ray absorption near edge structure (XANES) spectroscopy showed that Cr and As were in their less mobile Cr(III) and As(V) oxidation states. XANES analysis of Cu and Zn on selected samples indicated an association of Cu(II) with soil organic matter and Zn(II) with Al- and Fe-oxides or franklinite.     

HY1141和HY241菌产生的絮凝剂絮凝性能及水处理应用研究

从土壤中分离筛选得到絮凝剂产生菌HY1141和HY241,对高岭土悬浊液进行絮凝性能试验研究。试验结果表明：HY1141絮凝荆在ptt值为3．0时,絮凝率达到97．2％,HY241絮凝剂在pH值为4．0-7．0时,絮凝率在90％以上;絮凝剂的最佳投加量均为4mL／L,此时絮凝率分别达到98．2％和96．5％;HY1141和HY241絮凝剂所需CaCl2,最佳浓度分剐为0．5％和1．0％,此时絮凝率分刺为97．6％和96．8％;絮凝荆最佳静置时间分别为5min和10min。此外,两株菌所产絮凝刘对洪水和选矿废水都有一定的处理效果,且HY1141絮凝剂处理洪水效果较好,絮凝率为71．7％,COD去除率为81．8％;混合絮凝刺处理选矿废水效果较好,絮凝率为92．8％,COD去除率为96．0％。