城市景观水污染现状及处理技术

城市景观水体由于水质恶化而渐渐影响附近居民的正常生活,要从根本上保证水质需采取一定的水源保护和水处理措施。在景观水处理中,适用于景观水处理的工艺有很多,但工程实施中需要对其进行选择、优化、组合。随着社会不断发展和人们生活质量要求不断提高,景观水处理也必将成为继生活用水处理、工业用水处理后的又一给水处理新领域。     

啤酒废水处理站的工程设计

本项目以哈尔滨啤酒(沈阳)有限公司啤酒厂为设计对象,其啤酒废水处理规模为1500m3/d,进水CODCr2000~2800mg/L。采用预处理-预酸化-IC反应器-活性污泥法-过滤为主体工艺,出水达到《辽宁省污水与废气排放标准》(DB21-60-89中一级标准)。为啤酒行业废水综合治理提供了较好的工艺途径。     

Mine-drainage treatment wetland as habitat for herptofaunal wildlife

Land reclamation techniques that incorporate habitat features for herptofaunal wildlife have received little attention. We assessed the suitability of a wetland, constructed for the treatment of mine-water drainage, for supporting herptofaunal wildlife from 1988 through 1990 using diurnal and nocturnal surveys. Natural wetlands within the surrounding watershed were also monitored for comparison. The treatment wetland supported the greatest abundance and species richness of herptofauna among the sites surveyed. Abundance was a function of the frog density, particularly green frogs (Rana clamitans) and pickerel frogs (R. palustris), while species richness was due to the number of snake species found. The rich mix of snake species present at the treatment wetland was believed due to a combination of an abundant frog prey base and an amply supply of den sites in rock debris left behind from earlier surface-mining activities. Nocturnal surveys of breeding male frogs demonstrated highest breeding activity at the treatment wetland, particularly for spring peepers (Hyla crucifer). Whole-body assays of green frog and bullfrog (R. catesbeiana) tissues showed no differences among sites in uptake of iron, aluminum, and zinc; managanese levels in samples from the treatment wetland were significantly lower than those from natural wetlands. These results suggest that wetlands established for water quality improvement can provide habitat for reptiles and amphibians, with the species composition dependent on the construction design, the proximity to source populations, and the degree of acidity and heavy-metal concentrations in drainage waters.     

Sustainable Farming Practices: Ghanaian Farmers' Perception of Erosion and Their Use of Conservation Measures

/ Major responsibility for conserving forest biodiversity is often assigned to natural resource agencies. Often unknown is the appropriate administrative context for doing so, especially the organizational location for biodiversity programs in state government, suitable levels of financial and professional investment in biodiversity programs, processes useful for coordinating programs located in different administrative settings, and the effectiveness of biodiversity programs, especially conditions associated with programs judged to be very effective. Focusing on forests, a nationwide survey of 156 forestry agency and biodiversity program administrators in all 50 states was undertaken. Effective forest biodiversity programs were those with a long-range plan, administered as a single organizational unit, located in close organizational proximity to a state's forestry agency, actively providing management practice advice to landowners, administrators, and the public, and firm actions taken to ensure coordination with other natural resource programs.     

Nitrogen recovery in an integrated system for wastewater treatment and tilapia production

An integrated system, consisting of Up-flow Anaerobic Sludge Blanket (UASB)-duckweed-tilapia ponds was used for recovery of sewage nutrients and water recycling. A UASB reactor with 40 liter working volume was used as pre-treatment unit followed by a series of three duckweed ponds for nitrogen recovery. The treated effluent and duckweed biomass was used to feed fishponds stocked with Nile tilapia (Oreochromis niloticus). The UASB reactor was fed with raw, domestic sewage at 6 h hydraulic retention time. The three duckweed ponds were stocked with Lemna gibba and fed with UASB effluent at 15 days hydraulic retention time. Nitrogen recovery from UASB effluent via duckweed biomass represented 81% of total nitrogen removal and 46.5% from the total nitrogen input to the system. In subsequent fishponds the nitrogen recovery from duckweed as fish feed was in the range of 13.4–20%. This nitrogen in fish biomass represented 10.6–11.5 g N from the total nitrogen in the raw sewage fed to the UASB reactor. The growth performance of tilapia (Oreochromis niloticus) showed specific growth rates (SGR) in the range of 0.53–0.97. The range of feed conversion ratio (FCR) and protein efficiency ratio (PER) were 1.2–2.2 and 2.1–2.28, respectively. The results of the experiments showed total fish yield and net fish yield in the range of 17–22.8 ton/ha/y and 11.8–15.7 ton/ha/y respectively. In conclusion UASB-duckweed-tilapia ponds provide marketable by-products in the form of duckweed and fish protein, which represent a cost recovery for sewage treatment.     

Insights into multisource sludge distributed in the Yangtze River basin, China: Characteristics, correlation, treatment and disposal

Sludge is the by-product of wastewater treatment process. Multisource sludge can be defined as sludge from different sources. Based on the sludge properties of five typical cities in the Yangtze River basin, including Jiujiang, Wuhu, Lu'an, Zhenjiang and Wuhan, this study investigated and summarized the characteristic variations and distribution differences of multiple indicators and substances from municipal sludge, dredged sludge, and river and lake sediments. The results demonstrated pH of multisource sludge was relatively stable in the neutral range. Organic matter and water content among municipal sludge were high and varied considerably between different wastewater treatment plants. Dredged sludge had an obviously higher sand content and wider particle distribution, which could be considered for graded utilization depending on its size. The nutrients composition of river and lake sediments was usually stable and special, with lower nitrogen and phosphorus content but higher potassium levels. The sources of heavy metals and persistent organic pollutants in multisource sludge were correlated, generally much higher among municipal sludge than dredged sludge and river and lake sediments, which were the most important limitation for final land utilization. Despite various properties of multisource sludge, the final fate and destination have some overall similarities, which need to be supplemented and improved by standards and laws. The study provided a preliminary analysis of suitable technical routes for municipal sludge, dredged sludge, river and lake sediments based on their different characteristics respectively, which was of great significance for multisource sludge co-treatment and disposal in the future of China.     

Effects of water regime,crop residues,and application rates on control of Fusarium oxysporum f. sp. cubense

Biological soil disinfestation is an effective method to control soil-borne disease by flooding and incorporating with organic amendments, but field conditions and resources sometimes limited its practical application. A laboratory experiment was conducted to develop practice guidelines on controlling Fusarium wilt, a widespread banana disease caused by Fusarium oxysporum f. sp. cubense (FOC). FOC infested soil incorporated with rice or maize straw at rates of 1.5 tons/ha and 3.0 tons/ha was incubated under flooded or water-saturated (100% water holding capacity) conditions at 30°C for 30 days. Results showed that FOC populations in the soils incorporated with either rice or maize straw rapidly reduced more than 90% in the first 15 days and then fluctuated till the end of incubation, while flooding alone without organic amendment reduced FOC populations slightly. The rapid and dramatic decrease of redox potential (down to − 350 mV) in straw-amended treatments implied that both anaerobic condition and strongly reductive soil condition would contribute to pathogen inactivation. Water-saturation combined with straw amendments had the comparable effects on reduction of FOC, indicating that flooding was not indispensable for inactivating FOC. There was no significant difference in the reduction of FOC observed in the straw amendments at between 1.5 and 3 tons/ha. Therefore, incorporating soil with straw (rice or maize straw) at a rate of 3.0 tons/ha under 100% water holding capacity or 1.5 tons/ha under flooding, would effectively alleviate banana Fusarium wilt caused by FOC after 15-day treating under 30°C.     

江苏省太湖流域农村生活污水处理技术评价

农村生活污水处理技术种类繁多,实际应用效果参差不齐,且各类技术缺乏对实际工程实施的指导。针对江苏省太湖流域农村生活污水排放特点,研究了毛细管渗滤沟处理技术、厌氧池-人工湿地组合工艺、厌氧滤池-氧化塘-生态渠技术、SBR-化学除磷和膜生物反应器等技术的工艺参数、处理效果、投资估算和操作管理要求,并对各项技术进行综合评估。针对不同的污水处理规模,总结不同地区相应的推荐处理技术。     

一元回归分析在污水处理厂中的应用

以沈阳某污水处理厂的进水水质为例,用SPSS软件对COD和BOD进行回归分析。结果表明,COD和BOD之间具有线性关系,其一元线性回归方程为COD=35.76+2.26*BOD。利用该回归方程测算BOD,对预测值和实际值进行t检验,发现两者之间不存在显著性差异,从而表明利用回归方程测算BOD方便快速,有助于生产运行管理。     

企业环保设施市场化运营瓶颈的经济博弈分析

从经济学角度构建了企业环境污染的理论模型。并运用制度经济学与博弈论原理揭示我国企业环境污染行为与企业环保设施市场化运营瓶颈的内在原因，据此给出制度改革的有效建议。