养殖场废水中磺胺类和四环素抗生素及其抗性基因的定量检测

抗生素滥用及其诱导产生的抗生素抗性基因（antibiotic resistance genes,ARGs）污染已经引起人们的广泛关注。选取上海市某地养殖场作为研究对象,采用高效液相色谱-质谱法和实时荧光定量PCR法,对养殖场污水及附近农田灌溉渠河水中5种四环素及磺胺类抗生素,8种对应的ARGs的含量、特征及相关性进行了研究。研究结果显示,在采集的水样中均含有待检测的5种抗生素,养殖污水中抗生素含量高于农田灌溉河水,各样本中四环素类抗生素含量均略高于磺胺类抗生素,2种四环素抗生素总量为294.0~376.1μg﹒L-1,3种磺胺类抗生素总量为197.7~323.0μg﹒L-1。养殖场污水样本中8种ARGs均有检出,磺胺类抗性基因中sul（A）含量最高,绝对拷贝数为108.4108~1010.3728;四环素类抗性基因中tet（W）含量最高,绝对拷贝数为106.18805~107.8874。农田灌溉渠河水中除tet B（P）外,其它7种ARGs均有检出。样本中ARGs相对表达量总体呈现磺胺类ARGs高于四环素类ARGs的特点。抗生素浓度与ARGs相对表达量的Pearson相关性分析显示,样本中sul（Ⅲ）与磺胺类抗生素浓度存在较明显的正相关性,但其它几种ARGs与抗生素则未见或存在一定负相关性。表明除抗生素外,ARGs在水环境中的丰度可能与ARGs种类及其它环境因子有关。该研究将有助于认识上海地区养殖场废水中抗生素和ARGs污染状况,为进一步开展黄浦江水域抗生素尤其是ARGs的污染研究提供数据基础。     

中国茶叶中的氟近十年来的研究进展

主要对茶叶中氟的来源,氟含量,氟浸出率以及茶叶降氟措施研究作了详细的综述。大量的研究资料表明,土壤中的氟直接影响到茶叶中氟的含量,茶树吸收氟与土壤的pH值、有机质含量、粘粒含量、成土母质及土壤中的阳离子有关。大气污染影响茶叶氟含量主要是氟通过叶片气孔进入细胞,进而在茶树体内积累。水环境中氟的含量主要受土壤与大气环境的影响。茶叶中的氟含量随着叶片成熟度的增加而增加;茶叶等级越差,氟含量越高;原料粗老的茶类氟含量要比原料较嫩的茶类氟含量高;不同季节、茶树品种对氟吸收也存在差异性;茶树各部位氟累积强度依次为:叶>花蕾>籽>皮>细枝>骨干枝>细根>茎(主轴)>茎(主干)>主根>侧根;茶叶中氟浸出率与冲泡水温、冲泡时间、冲泡次数等有关。在茶叶加工过程中可以通过热水处理,添加化学试剂,改进生产工艺等措施来降低茶叶中的氟含量。此外,尚可以培育含氟量低的茶树品种。     

亚热带红壤丘陵区茶园土壤中Al和F的分布特征及其影响因素

以化学浸提的方法研究了亚热带红壤丘陵区茶园土壤中活性Al和F的溶出和剖面分布特征.结果表明,各浸提液对Al的浸提能力顺序为:1mol/L HCl>1mol/L NH4AC(pH4.8)>1mol/L KCl(pH5.5)>H₂O(pH6.8).同样,在4种浸提态F中,1mol/L HCl所提取F的含量最高,含量范围为6.62～38.8mg/kg,1mol/L KCl与1mol/L NH₄AC所提取F含量次之,分别为4.57～28.1mg/kg和5.76～32.17 mg/kg,水溶性F的含量最低,含量范围为0.95～4.18mg/kg.各浸提态Al和F主要集中于0～3cm的表层,土壤剖面分布有上高下低的特征.水溶性Al与F存在线性回归关系,其他各浸提态Al和相关浸提态F之间也为显著的正相关关系.土壤中各浸提态Al和F含量随植茶年限的增长而增加,同时也受土壤母质、土壤pH值和有机质影响.     

Screening of a potential leafhopper attractants and their applications in tea plantations

Abstract

Pheromones can be used as leafhopper attractants. However, commercial pheromone products, such as the Ingle lure, have certain limitations, including poor persistence in the field. In this study, (E)-2-hexenal, (Z)-3-hexen-1-ol, (Z)-3-hexenyl acetate, (E)-ocimene, linalool, and geraniol were selected and behaviorally tested as potential leafhopper attractants. Y-tube olfactometer tests showed that the C2 formulation was more effective than other formulations. In tea field trials, the number of leafhoppers caught by sticky board traps baited with C2 lures was greater than that caught by treatment. The number of leafhoppers attracted by the C2 lures was greater than that attracted by the commercial Ingle lures. Additionally, the total amount of active C2 components on lures was greater than that of the active components on the lure after 14 days. Thus, the results indicated that the C2 formulation may attract leafhoppers and have a greater persistence than other formulations in tea field.     

赤红壤地区茶叶施用有机无机复肥的效果初探

本试验比较了三种不同Ｎ／Ｋ２Ｏ的有机无机复肥和进口复肥在赤红壤茶园上的施用效果．结果表明，施用有机无机复肥能促进茶树生长，增大茶芽密度．提高茶叶产量，增加茶叶的茶多酚和氨基酸含量；且能增加土壤有机质含量，平衡土壤养分．有机无机复肥中的Ｎ／Ｋ２Ｏ对其肥效的发挥有重要作用，Ｎ／ｋ２Ｏ值以４．５为宜．     

Structural trends in agriculture and preservation of family farms

The characteristics and role of the family farm have profoundly influenced the quality of human ecology. Considerable debate exists about the role of the family farm in the United States. This article attempts to clarify aspects of this debate by: (a) examining various definitions of the family farm and the conclusions that flow from these definitions, (b) presenting results of a structural analysis of American agriculture to better understand the origins of the debate and the relationship between people and agriculture, and (c) discussing the relevancy of some data and concepts used in evaluating the consequences of the structure of the agricultural sector.     

Impact evaluation of agrotechnologies in watersheds

The special project RAISA (Advanced Researches for Innovation in Agricultural Systems) of the National Research Council of Italy concerns the development of new methodologies for the study and evaluation of the impact of agrotechnologies on the environment. In the project, several trans-disciplinary Units have worked together since 1990. The aim of the project is to define systems, using tools such as remote sensing and Geographical Information Systems, for decision making support in land planning and land use management, with particular attention to groudwater table pollution. The fundamental steps for evaluation of the impact of agrotechnologies on the Po river watershed, 75,000 km² in northern Italy, and Tevere (Tiber) river watershed, 17.169 km² in Central Italy are described here. The study concerns particular areas located in the western part of the Po River plain, where flooded rice is the main crop, and in the central plain of the Tevere basin where the risk of water pollution is considerable, due to small and medium sized swine breeding farms. The aspects considered were water pollution due to mineral nitrogen used to fertilize the rice crop and the nitrogen contained in the waste water from pig farms. For the Po river basin the methodology developed was based on the integration of satellite remote sensing images, and the available cartography, such as topographic and thematic maps, together with the hydrological and the toxicological data of the chemical fertilizers employed, summarized in maps of the groundwater table pollution hazard. A simpler evaluation was obtained in the Tevere river basin: the thematic layers were crossed in bi-directional matrices and the result merged with the map of the territorial distributionof the swine. In both cases the selected information was integrated and processed in Integrated sub-basin scale. The GISs led to the development of a user-friendly system for formalizing our knowledge of the degree of pollution hazard in simple and readable maps.Research supported by National Research Council of Italy, Special Project RAISA, sub-project N. 1 Paper N.     

植茶年限对土壤水稳性团聚体腐殖质组分特征的影响

退耕植茶是川西低山丘陵区响应退耕还林工程实施的重要措施之一.为了研究茶园土壤团聚体中腐殖质组分的分布特征,反映植茶对土壤质量的影响,选取不同植茶年限（18、25、33、55 a）的老川茶园为研究对象,以邻近撂荒地为对照（CK）,研究植茶对土壤团聚体中富里酸（FA）和胡敏酸（HA）分布的影响.结果表明:①不同植茶年限下,土壤富里酸含量（以质量分数计）在2.97~6.26 g/kg之间,胡敏酸含量在1.24~4.89 g/kg之间;随植茶年限的延长,土壤富里酸、胡敏酸含量先增加后降低,均在植茶25 a时达到最大值.②随着土壤团聚体粒径的减小,富里酸含量逐渐降低,胡敏酸则表现为≥5 mm粒径团聚体高于其他粒径.③土壤胡富比（HA/FA）在0.30~0.88之间,总体表现为≥5 mm和 < 0.25 mm粒径团聚体腐殖化程度较高,植茶25 a时大团聚体数量的增加有利于有机质含量和品质的提高.④逐步回归分析表明,≥5、2~5、0.25~0.5和 < 0.25 mm粒级团聚体中有机碳组分对水稳性团聚体的形成和稳定的影响较大.研究显示,植茶有利于土壤团聚体中腐殖质各组分的积累和腐殖化程度的增强,可增加土壤有机碳的稳定性;植茶25 a时土壤碳汇效应较强,植茶33 a后土壤固碳能力有所下降,可通过改善茶园施肥管理等措施保持茶园土壤的结构和肥力,以实现茶园土壤的可持续利用.      

紫外线-茶多酚联用对供水管网的消毒效果

针对传统消毒技术的安全风险问题,以维护供水管网水质安全为目标,引入茶多酚作为辅助消毒剂和紫外线消毒联用,模拟供水管网系统探究不同管材和水力停留时间下紫外线-茶多酚联合消毒的消毒效果,分析管壁生物膜形貌和菌落分布的变化.结果表明,75mg/L是紫外线-茶多酚联合消毒时茶多酚的较优投加量,可保持48h消毒效果.模拟管网运行过程中整体水质较好,但管材对管网消毒效果的影响较大,30d内球墨铸铁和UPVC管网中细菌量超过100CFU/mL的频率分别为80%和0%,紫外线-茶多酚联合消毒在UPVC管网中消毒持续性较强.与紫外线消毒相比,紫外线-茶多酚联合消毒对管壁生物膜的破坏效果更明显,且对生物膜中的蓝藻菌和肠道致病菌杀灭效果更强,有利于保障管网水质的安全性.     

Optimization of methyl orange removal from aqueous solution by response surface methodology using spent tea leaves as adsorbent

The effective disposal of redundant tea waste is crucial to environmental protection and comprehensive utilization of trash resources. In this work, the removal of methyl orange （MO） from aqueous solution using spent tea leaves as the sorbent was investigated in a batch experiment. First, the effects of various parameters such as temperature, adsorption time, dose of spent tea leaves, and initial concentration of MO were investigated. Then, the response surface methodology （RSM）, based on Box- Behnken design, was employed to obtain the optimum adsorption conditions. The optimal conditions could be obtained at an initial concentration of MO of 9.75 mg·L-1, temperature of 35.3℃, contact time of 63.8 min, and an adsorbent dosage 3.90 g· L-1. Under the optimized condi- tions, the maximal removal of MO was 58.2%. The results indicate that spent tea leaves could be used as an effective and economical adsorbent in the removal of MO from aqueous solution.