通海杞麓湖退塘还湖及生态修复工程研究

介绍了杞麓湖现状,在此基础上提出了退塘还湖及生态修复工程方程。具体提出了湖滨生态修复的范围、分区,主要技术经济指标,主要工程内容与规模,工程实施计划及对策措施,湖泊生态管理措施,对策建议等。     

某医院污水处理工程设计

A/O池-沉淀池-消毒工艺在处理医院废水中是可行的。原污水经过厌氧、好氧两个生物处理过程,可以同时去除水中大部分的COD、BOD5、悬浮物、氨氮、磷。通过实际的运行操作表明：该工艺具有效率高、能够脱氮除磷、处理效果好、投资低、占地面积小、运行费用低、管理操作方便等优点。     

异龙湖湖周鱼塘排水污染物排放总量研究

在进行现场调查的基础上,对异龙湖湖周的鱼塘排水水量进行估算,并在鱼塘排水前采集鱼塘水样进行监测分析,确定异龙湖湖周鱼塘的主要污染物浓度,计算异龙湖湖周鱼塘排水污染物排放总量。     

环渤海地区海冰水资源农业利用研究

环渤海地区盐碱滩涂地面积广阔,淡水资源紧缺现状制约着该地区土地资源开发和农业利用。新型海冰水资源的开发和利用有望打开这种尴尬局面。实验结果表明:海冰水灌溉下台田土壤耕作层平均盐分含量为2.45 g/kg,可以保障土壤耕层安全;3 g/L海冰水灌溉与无灌溉处理相比,油葵增产31.3%、甜高粱总糖量增产21.2%、紫花苜蓿增产27.0%。可见以海冰水为水源的"台田-浅池"综合利用模式对环渤海地区改良和利用盐碱地具有重要的参考价值。     

Nitrogen Removal by Stormwater Management Structures: A Data Synthesis

A comprehensive synthesis of data from empirically based published studies and a widely used stormwater best management practice (BMP) database were used to assess the variability in nitrogen (N) removal performance of urban stormwater ponds, wetlands, and swales and to identify factors that may explain this variability. While the data suggest that BMPs were generally effective on average, removal efficiencies of ammonium (NH₄), nitrate (NO₃), and total nitrogen (TN) were highly variable ranging from negative (i.e., BMPs acting as sources of N) to 100%. For example, removal of NO₃ varied from (median ±1 SD) ?15 ± 49% for dry ponds, 32 ± 120% for wet ponds, 58 ± 210% for wetlands, and 37 ± 29% for swales. Across the same BMP types, TN removal was 27 ± 24%, 40 ± 31%, 61 ± 30%, and 50 ± 29%. NH₄ removal was 9 ± 36%, 29 ± 72%, 31 ± 24%, and 45 ± 34%. BMP size, age, and location explained some of the variability. For example, small and shallow ponds and wetlands were more effective than larger, deeper ones in removing N. Despite well‐known intra‐annual variation in N fluxes, most measurements have been made over short time periods using concentrations, not flow‐weighted N fluxes. Urban N export is increasing in some areas as large storms become more frequent. Thus, accounting for the full range of BMP performance under such conditions is crucial. A select number of long‐term flux‐based BMP studies that rigorously measure rainfall, hydrology, and site conditions could improve BMP implementation.     

Diel and seasonal methane flux across water–air interface of a subtropic eutrophic pond

Abstract

Methane, which is an important greenhouse gas, has received less attention regarding its flux in ponds. Small ponds, whose area only occupies approximately 8.6%, comprise the bulk of CH₄ efflux from lakes and ponds on a global scale. However, temporal and spatial variability, as well as consequences of CH4 fluxes from ponds, remains unknown. The aim of this study was to examine using 4 field experiments diel methane (CH₄) fluxes from a subtropic eutrophic pond in different seasons. For the eutrophic pond, the mean CH₄ efflux for all seasons was 1.772?mg/m²/h, and CH₄ emissions in summer were approximately three-fold higher than total of winter, spring, and autumn. Methane diffusive emissions were positively correlated with water temperature, dissolved oxygen (DO) and air temperature but negatively related to pH and to the difference between water temperature and air temperature. The diel diffusive CH₄ flux among different seasons varied significantly. The CH₄ bubble flux did not differ markedly in winter, spring and autumn, but the quantity in summer was significantly different from all other seasons. Bubble is the main pathway for CH₄ emissions. The CH₄ ebullition flux accounts for 66, 71, 97 and 98% of the total in winter, spring, summer and autumn, respectively. On an annual scale, the CH₄ ebullition flux accounts for 77% of the total fluxes (diffusive?+?ebullitive). Our results show that further investigations need to be carried out to probe temporal variability of CH₄ fluxes in ponds located in different climate zones for better understanding of the global carbon budget, which is critical to predict future climate changes.     

生物塘处理富营养化巢湖水中试

利用生物塘对富营养化巢湖水进行中试,结果表明:浮萍、黑藻、狐尾藻和芦苇对总氮、总磷均有较好处理效果,其中黑藻对总氮、总磷的处理效果最好,芦苇对叶绿素的处理效果最好。7月份是生物塘处理污染物的最佳时期,4种水生生物的综合生物塘对总氮、总磷和叶绿素的最高去除率分别为92.0%、89.2%、97.8%。     

Simulation of thermodynamic transmission in green roof ecosystem

Green roofs entail the creation of vegetated space on the top of artificial structures. They can modify the thermal properties of buildings to bring cooling energy conservation and improve human comfort. This study evaluates the thermodynamic transmission in the green roof ecosystem under different vegetation treatments. Our model simulation is based on the traditional Bowen ratio energy balance model (BREBM) and a proposed solar radiation shield effectiveness model (SEM). The BREBM investigates energy absorption of different components of radiation, and the SEM evaluates the radiation shield effects. The proposed model is tested and validated to be efficient to simulate solar energy transmission in green roofs, with some major findings. Firstly, the solar radiation transmission processes might be considered as free vibration motion. Daytime positive heat storage of the green roof is 350-520 W·m⁻² on an hourly basis. Nighttime or afternoon negative value registers a rather constant magnitude of −60 W·m⁻². Daily net average is positive around 155-210 W·m⁻². Secondly, solar radiation vibration is highly correlated with plant structure. The canopy reflectance and transmittance are strongly correlated (R² = 0.87). The multi-layer shrub treatment has the highest shield effectiveness (0.34), followed by two-layer groundcover (0.27), and single-layer grass (0.16). Green roof vegetation absorbs and stores large amounts of heat to form an effective thermal buffer against daily temperature fluctuation. Vegetated roofs drastically depress air temperature in comparison with bare ground (control treatment). Finally, the thermodynamic model is relatively simple and efficient for investigating thermodynamic transmission in green roof ecosystem, and it could be developed into a broad solar radiant land cover model.     

海水养殖场底泥中转化硫和磷化合物的微生物及其多样性

对福建某近海养虾场底泥环境中硫和磷2种元素的微生物代谢进行了研究.结果表明,细菌代谢有机硫和无机硫产H₂S是养殖过程中造成H₂S污染的主要因素,利用半胱氨酸和硫代硫酸钠产生硫化氢的细菌数量分别为 1.6×10⁶和4.35×10³ 个·g^-1底泥;进一步研究发现,芽孢杆菌属、盐芽孢杆菌属和微杆菌属等细菌是产H₂S的优势菌群,而硫酸盐还原菌的数量较少,仅为25个·g^-1,其产H2S的作用不明显.研究还发现,转化有机磷和无机磷酸盐的优势菌群属于好氧细菌,其中分解卵磷脂的细菌和产磷酸酯酶细菌的数量分别为2.17×10⁵和 1.21×10⁶个·g^-1,转化磷酸钙的细菌数量为6.96×10³个·g^-1.本文从微生物学的角度探讨了养殖环境中硫、磷化合物的转化,提出细菌好氧代谢产H₂S是养殖环境潜在的污染因素,给出了一些改善和修复养殖环境生态的建议.     

Testing and performance analysis of a hollow fiber-based core for evaporative cooling and liquid desiccant dehumidification

In this study, an innovative heat and mass transfer core is proposed to provide thermal comfort and humidity control using a hollow fiber contactor with multiple bundles of micro-porous hollow fibers. The hollow fiber-based core utilizes 12 bundles aligned vertically, each with 1,000 packed polypropylene hollow fibers. The proposed core was developed and tested under various operating and ambient conditions as a cooling core for a compact evaporative cooling unit and a dehumidification core for a liquid desiccant dehumidification unit. As a cooling core, the fiber-based evaporative cooler provides a maximum cooling capacity of 502 W with a wet bulb effectiveness of 85%. As a dehumidification core and employing potassium formate as a liquid desiccant, the dehumidifier is capable of reducing the air relative humidity by 17% with an overall dehumidification capacity of 733 W and humidity effectiveness of 47%. Being cheap and simple to design with their attractive heat and mass transfer characteristics and the corresponding large surface area-to-volume ratio, hollow fiber membrane contactors provide a promising alternative for cooling and dehumidification applications.