城市景观水体中浮萍对水华的影响分析

为探究城市景观水体中浮萍对水华暴发的影响,于2015年3—9月在4处典型的景观河道进行采样点布设和检测分析。现场观测从2015年4月2日开始,各采样点陆续出现浮萍,且随着时间的延长,发现浮萍和水华是可以同时存在的;再将检测数据与2014年未出现浮萍生长覆盖的数据进行对比分析可知:浮萍对藻类的生长产生了竞争抑制,推迟了水华的暴发时间,减小了水华的暴发次数;对造成该结果的原因进行显著性分析可得:浮萍对藻类的抑制作用不主要表现在光照的遮挡,而主要是对营养盐的竞争,在有大量的浮萍生长覆盖时,TP成为了限制藻类生长的因素,而TN并不是藻类生长的限制性因素。     

九龙江北溪拟多甲藻水华防治与应急处置

2009年初以来,在福建省九龙江北溪的支流和干流连续发生了拟多甲藻(Peridiniopsis penardii)水华。经检测,拟多甲藻水华没有明显的生物毒性,但其所形成的深褐色水色和轻微藻腥味对该流域的龙岩、漳州和厦门三城市的生产和生活是造成了一定的影响。研究结果表明,在甲藻水华的防治与应急处置过程中,必须进一步加强组织体系建设,明确各职能部门职责,并根据不同水域的实际情况和季节变化,采取相应的物理、化学和生物方法予以防治和应急处置。     

Prymnesium parvum Control Treatments For Fish Hatcheries1

Barkoh, Aaron, Dennis G. Smith, and Gregory M. Southard, 2010. Prymnesium parvum Control Treatments for Fish Hatcheries. Journal of the American Water Resources Association (JAWRA) 46(1):161-169. DOI: 10.1111/j.1752-1688.2009.00400.x Abstract: In 2001, the ichthyotoxic microalga Prymnesium parvum caused massive fish kills and adversely affected fish production at the Texas Parks and Wildlife Department (TPWD) Dundee State Fish Hatchery. Since then, we have investigated several P. parvum bloom and ichthyotoxicity control treatments to develop management strategies that allow fish production and prevent the spread of the alga into unaffected hatcheries and impoundments. Current control successes include treatments for ponds, water supply, and a hazard analysis and critical control point program. For pond treatment, ammonium sulfate (as 0.14-0.25 mg/l un-ionized ammonia nitrogen for temperatures above 15°C), copper sulfate (2 mg/l), Cutrine^®-Plus (0.2-0.4 mg/l as copper), or potassium permanganate (3 mg/l above the potassium permanganate demand) controls P. parvum blooms. Copper sulfate at 1 mg/l controls P. parvum but is unable to eliminate ichthyotoxicity whereas potassium permanganate at 2 mg/l above the potassium permanganate demand controls ichthyotoxicity. For water treatment, ultraviolet (UV) light at 193-220 mJ/cm² doses or ozone at 0.4-1.2 mg/l for 6 min destroy P. parvum cells and reduce or eliminate ichthyotoxicity. A combination UV and ozone treatment appears to provide the best results; however, successful treatments depend on dosage relative to cell density and toxin concentration. To prevent the spread of the alga, hatchery fish delivery units and equipment are cleaned with household bleach (10% solution for 15 minutes) or hydrogen peroxide (62.5-12,500 mg/l for 0.25-24 hours). These treatments are tailored to water quality conditions and the fish species cultured at affected TPWD hatcheries. We recommend that other users test these treatments before applying them to ponds or other impoundments containing fish or other aquatic life.     

Impact of Land-Based Sources On Marine Environment: Phytoplankton Blooms Within an Annual Cycle

The discharge water into the western region of Alexandria (Egypt), creates suitable conditions for the acceleration of the phytoplankton growth; daily replenishment of nutrients and development of density stratified water column. Water transparency and ammonia concentrations seem to be affecting the variations of the numerical standing crop. Eight phytoplankton bloom pulses of different causative species were observed. Asterionella glacialis represents a newly recorded red tide species in the neritic waters of Alexandria.     

建筑施工中临边高处坠落危险源影响空间建模

将建筑施工中临边坠落的特性模型化,对于预防建筑施工中伤亡事故具有重要的意义。在分析人或物临边高处坠落事故特点的基础上,给出施工工作面内外2种危险源影响空间范围的定义及其数学表达函数,构建相应的危险源影响空间中危害能量分布的数学模型,提出它对人体不同部位伤害程度的评估分析思路,并在大面积碰撞和小面积碰撞2种情况下,建立该危害能量对人体头枕部伤害程度的评估分析方法。通过上海某个6层框架结构教学楼案例,对上述数学模型和评估分析方法进行验证。这为在进行施工计划安排时,考虑危险源影响空间的影响,降低安全事故发生的可能性创造条件,也为安全事故事前预防提供新思路。     

Foraminifera as bioindicators in coral reef assessment and monitoring: the FORAM Index. Foraminifera in Reef Assessment and Monitoring

Coral reef communities are threatened worldwide. Resource managers urgently need indicators of the biological condition of reef environments that can relate data acquired through remote-sensing, water-quality and benthic-community monitoring to stress responses in reef organisms. The FORAM (Foraminifera in Reef Assessment and Monitoring) Index (FI) is based on 30 years of research on reef sediments and reef-dwelling larger foraminifers. These shelled protists are ideal indicator organisms because: Foraminifers are widely used as environmental and paleoenvironmental indicators in many contexts; Reef-building, zooxanthellate corals and foraminifers with algal symbionts have similar water-quality requirements; The relatively short life spans of foraminifers as compared with long-lived colonial corals facilitate differentiation between long-term water-quality decline and episodic stress events; Foraminifers are relatively small and abundant, permitting statistically significant sample sizes to be collected quickly and relatively inexpensively, ideally as a component of comprehensive monitoring programs; and Collection of foraminifers has minimal impact on reef resources.USEPA guidelines for ecological indicators are used to evaluate the FI. Data required are foraminiferal assemblages from surface sediments of reef-associated environments. The FI provides resource managers with a simple procedure for determining the suitability of benthic environments for communities dominated by algal symbiotic organisms. The FI can be applied independently, or incorporated into existing or planned monitoring efforts. The simple calculations require limited computer capabilities and therefore can be applied readily to reef-associated environments worldwide. In addition, the foraminiferal shells collected can be subjected to morphometric and geochemical analyses in areas of suspected heavy-metal pollution, and the data sets for the index can be used with other monitoring data in detailed multidimensional assessments.     

CONTROL OF SUSPENDED SOLIDS AND PHYTOPLANKTON WITH FISHES AND A MUSSEL1

ABSTRACT: Filtering efficiency of the fathead minnow (Pimephales promelas), gizzard shad (Dorosoma cepedianum), carp (Cyprinus carpio), and a freshwater mussel (Elliptio coinpianata) was measured in field and laboratory trials to assess the ability of each species to control phytoplankton and suspended solid densities. All fish species tested were ineffective filterers and generally increased, rather than suppressed, algal and suspended solid concentrations. Filtering efficiencies of fish varied between -354 and 84 percent, depending on the size, shape, abundance, palatability, composition, and resistance to digestion of the particles. Because of poor filtering abilities, unpredictable feeding habits, and sensitivity to stress, the fish species examined are not effective biological controls in waste lagoons. In contrast, the freshwater mussel Elliptio was a highly effective control organism, averaging 66 percent filtering efficiency over a wide size range of algal and suspended particles. Filtration efficiency was positively correlated with mussel density. Elliptio was efficient at filtering small particles, which are particularly difficult to remove. Mean filtration rates ranged from 53 to 134 ml/mussel/h depending on the algal species consumed and algal densities (range 50–180,000 cells/ml) and 3 mg/L/mussel/h on suspended solids (range 14 to 112 mg/L). Water clarification was facilitated by both direct consumption and pseudofeces deposition. Elliptio and probably other mussel species can effectively control algae and suspended solids in wastewater lagoons and eutrophic lakes, if environmental conditions, especially dissolved oxygen levels, are suitable (>5 mg/L) for their survival.     

Copper, Copper Mining Effluents and Grazing as Potential Determinants of Algal Abundance and Diversity in Northern Chile

We experimentally tested threealternative hypotheses to explain the low algaldiversity and abundance in an intertidal zonereceiving the effluents of the copper mine El Salvadorin northern Chile. Our results demonstrated thatalgae were able to grow at the levels of dissolvedcopper detected in coastal waters of the area. Duringthe assays, growth and regeneration in several red,green and brown adult algae and juvenile Lessonia nigrescens were normal at copper levels of150 g L^-1 or, in some cases, higher. Wealso found that the coastal sea water mixed with theeffluent was not lethal to algae, although in somecases minor effects on growth were detected. Theseresults indicate that today's low algal diversity andabundance can not be explained by the current copperlevels in the area nor by the effect of the effluent.Exclusion of grazers, however, resulted in a fastcolonization by various algal species. This, togetherwith atypically high grazer density at the areas underthe influence of the effluent, strongly suggests thatherbivory, a factor not directly related to the miningoperation, is likely to be responsible for the lowalgal diversity and abundance in the studied locality.     

小型露天采石场危险程度评价系统的应用研究

介绍了小型露天采石场的特点，通过对小型露天采石场的危险有害因素分析，指出坍塌、滑坡、物体打击、高处坠落、爆破、运输事故、机电设备事故、粉尘、山洪是小型露天采石场常见的危险及有害因素。危险程度的专家评价系统能快速地跟踪和准确地预测小型露天采石场危险程度，提高安全评价的效率并及时提出合理的安全对策措施。     

模拟显示屏的研究及其应用

分析了固定式监测有毒气体报警系统在某些条件下使用的弊端，通过研制模拟显示屏监控主机，使这类系统适合在各种工矿条件下使用。