微生物絮凝剂的研究、应用及存在的问题

介绍了微生物絮凝剂的研究及应用现状,包括产生絮凝剂的微生物种类、微生物絮凝剂的絮凝机理,以及微生物絮凝剂的应用。同时提出了微生物絮凝剂在研究、应用中存在的问题和今后的发展方向。     

微生物絮凝剂的研究方法和进展

通过分析目前国内外微生物絮凝的研究现状，归纳了微生物絮凝剂的一般研究方法，综述了微生物絮凝剂的研究成果，提出了微生物絮凝剂研究中亟待解决的问题和建议。     

微生物絮凝剂的研究及应用前景

对微生物絮凝剂的研究及应用进展进行综述,包括产生絮凝剂的微生物种类,微生物絮凝剂的提取纯化,微生物絮凝剂的絮凝机理,影响因素,研究动向以及微生物絮凝剂的应用。     

新型微生物絮凝剂的研究进展

综述了近些年来国内外微生物絮凝剂的发展概况,并对微生物絮凝剂的絮凝机理进行了探讨.分别介绍了单菌株生物絮凝剂、复合型生物絮凝剂、有效微生物群以及微生物絮凝剂的生物学研究,对微生物絮凝剂的发展趋势及其应用情况进行了分析.     

微生物絮凝剂的研究现状与发展趋势

本文综述了国内外关于微生物絮凝剂的研究、应用现状。阐述了研究和开发微生物絮凝剂的必要性 ;概括了其产生菌的筛选、鉴定及培养条件 ;讨论了微生物絮凝剂的结构、特性、性能及作用机理 ;列举了微生物絮凝剂的应用 ;最后 ,展望了微生物絮凝剂的研究发展方向。     

微生物絮凝剂的特性研究及其进展

微生物絮凝剂具有高效、安全、不污染环境等特点，已日益受到重视，综述了微生物絮凝剂的研究发展和应用现状，对絮凝性微生物的培养及絮凝剂的特性进行总结，并展望了其发展趋势。     

微生物絮凝剂的制备与发展方向

文章对无机絮凝剂、有机合成高分子絮凝剂和微生物絮凝剂三种絮凝剂进行了比较,提出研究和开发絮凝效果好、应用范围广、易生物降解、对环境安全的微生物絮凝剂就成为必然,并综述了微生物絮凝剂其产生菌的筛选、鉴定、培养、微生物絮凝剂的提取和纯化、微生物絮凝剂的化学组成分析和合成途径的探索;列举了微生物絮凝剂对畜产废水有机物的去除、对废水中COD、BOD的去除、对印染废水脱色的应用、对工业废水重金属离子的脱除,最后,展望了微生物絮凝剂的研究发展方向。     

微生物絮凝剂的研究进展及应用

系统介绍了微生物絮凝剂的定义、成份、制备及微生物絮凝剂的研究与应用进展等方面的知识,其中包括微生物絮凝剂的产生和培养条件、作用机理、合成絮凝剂的微生物种类,并预示了今后微生物絮凝剂领域的几个重要研究方向。     

微生物絮凝剂

絮凝剂已广泛用于各种工业废水处理。按照生产方式,通常,絮凝剂可分为3类:有机高分子絮凝剂,如聚丙烯酰胺;无机絮凝剂,如铝盐、铁盐;微生物絮凝剂。前2类常用于废水预处理及污泥脱水,而微生物絮凝剂则是目前正在开发的新类型絮凝剂,应用前景广阔。微生物絮凝剂是利用生物技术,通过细菌、真菌等微生物培养方法生产的,不存在二次污染,使用安全、方便。因此,微生物絮凝剂的开发,日益引人注目。随着生物技术的发展,有可能廉价地大量生产。一、生产微生物絮凝剂的微生物某些真菌和细菌能用于微生物絮凝剂的生产。J.Nakamura等人早在1976年就对能产生絮凝效果的微生物进行了研究。从霉菌、细菌、放线菌、酵母菌等214种菌株中,筛选出19种具有絮凝能力的微生物。其中,霉     

微生物絮凝剂研究与应用进展

本文论述了微生物絮凝剂开发应用的必要性，介绍了微生物絮凝剂的种类和研究概况，分析了微生物絮凝剂的絮凝机理及其影响因素，列举了微生物絮凝剂的应用实例，认为今后微生物絮凝剂在环境污染治理中，特别是回收废水中有益物质的过程中将占据重要地位。     

基于降水Z指数的朝鲜降水及旱涝时空特征

利用TRMM（Tropical Rainfall Measuring Mission,TRMM）3B43月降水数据,并结合降水Z指数,研究朝鲜1998—2018年的降水和旱涝时空格局。结果表明：TRMM与站点观测降水数据有显著的相关性。朝鲜降水季节性特征明显,57.29%的降水集中在夏季,空间上自东北部沿海岸线向东南递增。朝鲜的区域综合旱涝等级基本处于正常状态,偏旱和偏涝发生的频率最高,其次是大旱和大涝,极旱和极涝发生的频率最低,夏季和冬季干旱发生最为频繁,而洪涝在秋季频发。朝鲜北部发生旱涝事件的频率明显高于南部,咸镜山脉和盖马高原是旱涝的多发地区,温泉平原则最不易受到旱涝影响。春季、夏季和秋季均呈现洪涝强度增强的趋势。夏季洪涝强度加剧的趋势明显,中北部地区通过95%的显著性检验。     

世界三大黑土区水土流失与防治比较分析

论文首先明晰了黑土及黑土区的概念与范围界定,将中国东北黑土区分为典型黑土区与黑土区两个层次。在此基础上对世界三大黑土区在成土条件,开发利用过程、水土流失及水土流失防治模式方面进行了对比分析。通过比较分析认为:在自然条件上虽然三大黑土区具有一定的相似性,但我国东北黑土区由于地势起伏相对较大,更易遭受水土流失的危害;国外两大黑土区大规模的开发利用比我国黑土区相对早一些,大规模的农业开垦与不合理的耕作方式是世界三大黑土区水土流失与土地退化的主要原因;国外两大黑土区主要以风蚀为主,我国东北黑土区则是以水蚀为主,但风蚀面积也较大;国外两大黑土区在耕作制度、土地使用政策、水土保持资金投入、水土保持宣传教育及科学试验等方面已经采取了相对有效的措施,我国在这些方面还相对滞后。通过对国外黑土区水土流失治理的借鉴与思考,提出了我国东北黑土区在水土流失防治方面亟待解决的几个问题。     

Contribution of additives Cu to its accumulation in pig feces： study in Beijing and Fuxin of China

Massive amounts of pig manure are produced by intensive pig farm in China, and the composition of pig manure has changed much due to the use of feed additives. However, little is known about the exact Cu （copper） feed as additives or present as contaminants in pig feed and the residues in feces. One hundred and thirty-seven feeds and one hundred and forty-two fecal samples from 48 pig farms were collected in Beijing and Fuxin cities in 1999 and 2005, respectively. The concentrations of Cu were in the range of 6.86-395.19 mg/kg in the feed samples, and the mean values were in the order of weaner〉 grower-finisher〉 sow＇s feeds. The high concentrations over EU recommendations implied that excessive levels of Cu are fed on many pig farms in Beijing and Fuxin. Cu was also present in high concentrations in feces, and concentrations were highly variable. Cu concentrations in the feces from grower-finisher and weaner pigs were significantly greater than feces of sows. The super-intensive and small-scale farms had higher levels of Cu in feces than the middle farms. Cu concentrations in pig feces were approximately 5-times greater than in pig feeds. Feed management in grower-finisher pigs on super-intensive and small-scale pig farms is needed to reduce high Cu concentrations in feces and risks to soil contamination while feces are land-applied.     

Distribution of mercury in different environmental compartments in the aquatic ecosystem of the coastal zone of the Southern Baltic Sea

The aim of this study was to characterize mercury (Hg) contamination in the coastal waters of the Southern Baltic Sea, and to investigate transformations of Hg in the initial links of the marine food chain. Concentrations of Hg in water, particulate matter, plankton and macrophytes at various stations in the coastal zone (a bay with restricted water exchange, near an industrial city, river mouths, and the open sea) were measured in 2006–2008. Hg concentrations observed in the Southern Baltic varied greatly, showing the highest average values in all environmental compartments near the river mouths. In shallow, sheltered parts of the gulf, where water exchange is restricted, Hg concentrations in the water and in macrophytes were elevated relative to those in the coastal zone of the deeper part of the bay and in the open Baltic. Distance to the river mouth, terrestrial runoff, and quantity and quality of organic matter were more important than seasonal variations in controlling Hg and HgSPM concentrations in water samples. Mercury concentrations in the surface microlayer at the air/sea interface were over 10 times higher than those in the bulk surface water. Concentrations of Hg in macrophytes in the winter were significantly higher than those in the warm seasons (spring, summer, autumn). This was probably the combined effect of higher availability of Hg in porewaters and leaf growth inhibition.     

长期不同耕作方式下紫色水稻土和上覆水中汞及甲基汞的分布特征

为了解不同耕作方式对稻田中甲基汞的影响,在免耕冬水、垄作免耕、厢作免耕、水旱轮作和常规平作等5种耕作方式的长期定位试验地,分层采集土壤和上覆水样品,分析了汞及甲基汞的垂直分布特征.结果表明,免耕冬水、垄作免耕以及厢作免耕条件下土壤总汞含量在10~20 cm层最高,其中免耕冬水富集效果相对明显;而水旱轮作和常规平作处理则随土层加深呈下降趋势,其中水旱轮作更有利于汞的迁移转化.免耕冬水、厢作免耕、常规平作土壤甲基汞含量在剖面的分布规律与土壤总汞类似,除水旱轮作土壤汞甲基化能力在底层比表、中层较强外,其余4种处理则相反.5种耕作方式下稻田上覆水中溶解态汞(DHg)和溶解态甲基汞(DMe Hg)含量均随水深而增加,且水旱轮作和常规平作相对较高.各处理孔隙水中DHg含量与该层次土壤总汞含量有关,两者在土壤剖面上的波动趋势基本相同.免耕冬水、垄作免耕的孔隙水中DMe Hg含量及DMe Hg占DHg比例均在10~20 cm层出现最大值.水旱轮作和常规平作的孔隙水DMe Hg含量则相反,在10~20 cm层有最低值,两种处理的DMe Hg占DHg比例随土壤深度增加而上升.不同处理孔隙水中DMe Hg含量及DMe Hg占DHg比例均大于对应处理上覆水的值.     

Effects of two sludge application on fractionation and phytotoxicity of zinc and copper in the soil

The potential harm of heavy metals is a primary concern in application of sludge to the agricultural land. A pot experiment was conducted to evaluate the effect of two sludges on fractionation of Zn and Cu in soil and their phytotoxicity to pakchoi. The loamy soil was mixed with 0%, 20%, 40%, 60% and 80% (by weight) of digested sewage sludge (SS) and composted sludge (SC). The additions of both sludges caused a significant raise in all fractions, resulting in that exchangeable (EXCH) and organic bound (OM) became predominance of Zn and organic bound Cu occupied the largest portion. There was more available amount of Zn and Cu in SS treatments than SC treatments. During the pot experiment, the concentration of Zn in EXCH, carbonate (CAR) and OM and Cu in EXCH and OM fractions decreased in all treatments, so their bioavailability reduced. Germination rate and plant biomass decreased when the addition rate was high and the best yield appeared in 20% mixtures at the harvest of pakchoi. The two sludges increased tissue contents of Zn and Cu especially in the SS treatments. Zn in pakchoi was not only in relationship to ΔEXCH and ΔCAR forms but also in ΔOM forms in the sludge-soil mixtures. Tissue content of Cu in pakchoi grown on SC-soils could not be predicted by ΔEXCH. These correlation rates between Zn and Cu accumulation in pakchoi and variation of different fractions increased with time, which might indicate that sludges represented stronger impacts on the plant in long-term land application.     

黄、渤海区沉积物中磷的分布

对1998年9月和1999年5月的渤海航次、1998年5月南黄海航次、1999年8月北黄海航次所采集的表层和柱状沉积物样品中总磷和无机磷的含量及分布进行了系统分析和讨论，结果表明：黄、渤海沉积物无机磷占总磷的70%-80%，以无机磷为主，有机磷次之。受海流及陆地河流注入的影响，渤海海区沉积物中无机磷的总磷含量的最大值出现在黄河口附近，而黄海海区沉积物中无机磷和总磷含量的最大值出现在南黄海的西南部；整个黄、渤海海区无机磷和总磷含量的最小值则出现在山东半岛的成山头附近与朝鲜半岛西海岸之间的海区。由于海流作用及生物扰动，所采集的柱状样品中磷的含量产生了一定的波动，但总体趋势还是表层沉积物中磷的含量略高，向下销有减小。     

2016~2018年采暖季太行山沿线城市PM2.5污染特征分析

对2016年、2017年采暖季太行山沿线传输通道城市大气中PM_2.5的OC、EC和水溶性离子进行分析,并利用特征组分比值和元素富集因子变化研究该传输通道的污染特征.结果表明,2017年采暖季通道整体较2016年同期空气质量改善良好,PM_2.5浓度由2016年的171.86μg/m³下降为123.90μg/m³.太行山中部城市2017年采暖季较2016年同期PM_2.5浓度下降显著,2a采暖季SNA离子（SO^2-,NO₃^-,NH₄⁺ 3种离子总称）浓度与占比呈现"北低南高",加之SNA/EC比值"北低南高",表明南部城市二次无机生成较为严重.而OC、EC浓度与占比呈现"北高南低",Cl^-/K⁺比值和元素Zn、Ba的富集因子北部均高于南部,表明北部城市可能受燃煤和机动车源等一次排放影响较大;各城市2017年采暖季SO₂、NO₂、CO浓度有所下降,且均呈现"北高南低"趋势,进一步表明北部城市一次排放较为严重.     

川中丘陵区不同下垫面集水区氮磷流失特征

通过对2019~2020年不同下垫面集水区(农田集水区与复合集水区)径流及氮磷浓度的连续逐日定位监测,研究川中丘陵区不同下垫面集水区氮磷径流流失过程与强度,探讨下垫面对集水区氮磷径流流失特征的影响.结果表明:不同集水区的径流过程因下垫面不同而存在明显差异,农田集水区内的水田和坑塘的拦蓄作用滞缓了汇流过程,而复合集水区中居民点、公路等不透水下垫面缩短了汇流时间,使得复合集水区的降雨径流量峰值更高,响应速度较农田集水区快12~25min,年径流深较农田集水区多28.1%;次降雨径流过程中磷浓度变化较氮更剧烈,浓度峰值出现时间较氮早约1.2h,在降雨后期磷浓度下降速度更快,降幅更大;复合集水区的氮磷平均事件浓度(EMC)、峰值浓度均高于农田集水区,且两集水区氮流失形态均以硝酸盐氮为主,占总氮的65.9%;磷流失以颗粒态为主,占总磷的67.5%;复合集水区的氮磷流失负荷分别是农田集水区的3.01和4.03倍,氮磷流失强度分别是农田集水区的1.88和2.51倍.因此,复合集水区内氮磷随径流流失的防控可能是未来川中丘陵区面源污染治理的重点.     

桑沟湾贝类养殖海域石油烃污染状况及其对贝类质量安全的影响

2008年1～11月在桑沟湾贝类养殖海域分别采集表层海水、表层沉积物和养殖贝类样品,进行了石油烃含量分析.依据石油烃含量检测结果,分析了桑沟湾贝类养殖海域海水和沉积物中石油烃含量的分布和变化趋势以及贝类体内石油烃含量水平和种间差异,并对3种介质中石油烃的污染状况进行了评价,最后探讨了贝类体内积累的石油烃及对贝类质量安全...