Preliminary Evaluation of the Use of Phosphogypsum for Reef Substrate. Ii. A Study of the Effects of Phosphogypsum Exposure On Diversity and Biomass of Aquatic Organisms

The effects of cement consolidated phosphogypsum (PG) on marine organisms was investigated under natural conditions in four 1000 m² estuarine ponds. Two ponds were seeded with 160 kg of PG arranged in aggregations of blocks and two ponds received similar mass of sand/cement blocks. Meiofauna were sampled quarterly and PG did not affect total meiofauna or major taxa (nematodes and copepods) density. Abundant species of copepods either were slightly increased in ponds with PG or were inconsistently affected.

All ponds were drained after one year. Three species of macroinvertebrates and 15 species of fishes were collected. Diversity indices showed modest but inconsistent variation among ponds. Only Pond 1 (control) and Pond 4 (experimental) had similar species abundances and all ponds showed unique distributions of biomasses among species. Thus, no differences in community structure attributable to the presence of PG could be detected among benthic invertebrates, natant invertebrates, or fishes.     

一株茎点霉菌的抗镉机制

从矿区土壤筛选到一株对镉具有较强抗性和富集能力的丝状真菌,编号为F2,根据其形态主要是分生孢子器的特征鉴定为茎点霉菌.对不同镉浓度液体培养下菌体的生长及培养液的pH值变化作了分析,利用扫描电镜、透射电镜与能谱分析相结合的方法研究镉在F2胞内外的沉积作用及分布情况,从而分析该菌对镉的抗性和富集机制.结果表明,100mg/L的镉浓度下,在细胞壁及周围区域存在大量颗粒状镉沉积物,而在菌体表面也有沉淀物附着.因此胞内外沉积作用可能是该菌对高浓度镉的抗性和富集作用的重要途径,而且因为该菌生长过程中尤其是高镉浓度下pH值的大幅度上升,沉积过程可能与该菌在生长过程中产生碱性物质有关.     

基于BP模型的大气污染预报方法的研究

BP模型是目前最为广泛应用的神经网络模型之一,它是一种简单而又非常有效的算法.笔者将BP网络模型引入到大气污染预报领域,并根据大气污染物含量与气象要素的关系建立了大气污染物含量的神经网络预报模型.计算结果表明,BP模型应用于大气污染预报具有较高的预测精度和良好的泛化能力,它为信息社会的城市空气污染预报工作提供了一种全新的思路和方法.      

螯合沉淀法处理电镀废水的工业实践

介绍了一个采用螯合沉淀法处理电镀废水的典型工业实例。在工业装置上,进行了氢氧化钠、硫化钠和DT-CR去除重金属离子效果的对比,讨论了DTCR的加入量与处理成本的关系和pH值对DTCR用量的影响。结果表明,将废水的pH值调至8.0~8.5后再加DTCR,可以使DTCR的使用量最少,处理成本最低;此法对重金属离子的去除效果远优于传统化学沉淀法。     

20世纪90年代以来上海地区降水资源变化研究

为了揭示20世纪90年代上海地区降水资源的变化特点,根据1991-2003年上海地区11个站降水资料,在与前30年(1961-1990年)平均比较的基础上,统计分析1991年以来降水量、降水日数、相对湿度、蒸发量、降雪日的变化情况,结果表明:20世纪90年代以后,上海地区年平均降水量增加11%,汛期平均雨量增加18%,年平均降水日数却略有减少,这样使年平均降水强度增强了12%,季节分配格局改变,区域分布格局未变;年平均相对湿度和年平均蒸发量略减小,年平均降雪日数减少5d。     

基于人工神经网络的造纸废水处理动态仿真

研究了人工神经网络对废纸造纸废水处理过程动态仿真的可行性,采用误差反向传播网络(BP网)建立了表征原水COD、加药量、进水流量、历史出水COD与预计出水COD之间复杂关系的动态模型,并对不同训练方法进行了比较,发现带有动态调整的方法具有较好的效果,其模型的计算输出值与过程的实际输出值具有较好的一致性.对造纸厂现场排放的废水的实验表明,该模型可用于废纸造纸废水处理的动态描述.     

TA对印染废水处理效果的影响

印染综合废水的酸析预处理效率主要受废水中对苯二甲酸（TA）含量的影响,且印染综合废水酸析规律与纯TA配制液相比较存在一定的差异,分别对纯TA配制液,印染综合废水,加TA后的废水,酸析预处理后的废水进行好氧生化处理试验,研究其降解规律与去除效率,结果表明TA属易好氧生化物质,它的存在可提高废水的可生化性。     

Marshaling Adaptive Capacities within an Adaptive Management Framework to Enhance the Resiliency of Wastewater Systems

We assess adaptive capacity and adaptive management as measures of wastewater (WW) system resiliency using data from interviews with WW system managers (hereafter managers) impacted by past storms. Results suggest the most resilient WW systems are those with high adaptive capacities that employ an adaptive management approach to make ongoing adaptation investments over time. Greater amounts of generic adaptive capacities (i.e., skilled staff and good leadership) help smooth both day‐to‐day and emergency operations and provide a foundation for adaptive management. In turn, adaptive management helps managers both build more generic adaptive capacities, and develop and employ greater amounts and diversity of specific adaptive capacities (i.e., soft and/or hard adaptations) that are especially important for enhancing and sustaining resiliency. Adaptive management also enables managers to better understand their system's vulnerabilities, how those vulnerabilities change over time, and what specific actions may reduce those vulnerabilities. Finally, our work suggests WW system resilience critically depends on the capacities of the human systems for building resilience as much as or more so than relying only on physical infrastructure resilience. Our work contributes to filling an important gap in the literature by advancing our understanding of the human dimensions of infrastructure resilience and has practical implications for advancing resilience in the WW sector.     

Selecting for Tolerance against Pathogens and Herbivores to Enhance Success of Reintroduction and Translocation

Abstract: Some species have insufficient defenses against climate change, emerging infectious diseases, and non‐native species because they have not been exposed to these factors over their evolutionary history, and this can decrease their likelihood of persistence. Captive breeding programs are sometimes used to reintroduce individuals back into the wild; however, successful captive breeding and reintroduction can be difficult because species or populations often cannot coexist with non‐native pathogens and herbivores without artificial selection. In captive breeding programs, breeders can select for host defenses that prevent or reduce pathogen or herbivore burden (i.e., resistance) or traits that limit the effects of parasitism or herbivory on host fitness (i.e., tolerance). We propose that selection for host tolerance may enhance the success of reintroduction or translocation because tolerant hosts generally have neutral effects on introduced pathogens and herbivores. The release of resistant hosts would have detrimental effects on their natural enemies, promoting rapid evolution to circumvent the host resistance that may reduce the long‐term probability of persistence of the reintroduced or translocated species. We examined 2 case studies, one on the pathogenic amphibian chytrid fungus ( Batrachochytrium dendrobatidis [Bd]) and the other on the herbivorous cactus moth ( Cactoblastis cactorum) in the United States, where it is not native. In each case study, we provide recommendations for how captive breeders and managers could go about selecting for host tolerance. Selecting for tolerance may offer a promising tool to rescue hosts species from invasive natural enemies as well as new natural enemies associated with climate change‐induced range shifts.     

WATERSHED SCALE MODELING OF CRITICAL SOURCE AREAS OF RUNOFF GENERATION AND PHOSPHORUS TRANSPORT1

ABSTRACT: A curve number based model, Soil and Water Assessment Tool (SWAT), and a physically based model, Soil Moisture Distribution and Routing (SMDR), were applied in a headwater watershed in Pennsylvania to identify runoff generation areas, as runoff areas have been shown to be critical for phosphorus management. SWAT performed better than SMDR in simulating daily streamflows over the four‐year simulation period (Nash‐Sutcliffe coefficient: SWAT, 0.62; SMDR, 0.33). Both models varied streamflow simulations seasonally as precipitation and watershed conditions varied. However, levels of agreement between simulated and observed flows were not consistent over seasons. SMDR, a variable source area based model, needs further improvement in model formulations to simulate large peak flows as observed. SWAT simulations matched the majority of observed peak flow events. SMDR overpredicted annual flow volumes, while SWAT underpredicted the same. Neither model routes runoff over the landscape to water bodies, which is critical to surface transport of phosphorus. SMDR representation of the watershed as grids may allow targeted management of phosphorus sources. SWAT representation of fields as hydrologic response units (HRUs) does not allow such targeted management.