畜禽养殖行业废水排放标准的研究

讨论了畜禽养殖行业的排放污水、粪渣及恶臭的污染状况;综合国内外对畜禽场排放污水所采用的治理技术、达到的各项指标及中国目前的经济状况、技术条件,提出畜禽养殖行业排放污水的生化指标上限值,COD_(Cr)、BOD_5、SS、KN、TP分别为200、80、150、20、2.0mg/L,pH为6.5～9.0;卫生指数的粪大肠菌群数少于10~4个/L,蛔虫卵标准值为少于2个/L,粪渣经无害化处理后,蛔虫卵死亡率>95％;恶臭标准按感官作用阀值,采用国家2级标准。     

不同畜禽养殖场中气载抗生素抗性基因的污染特征与季节性变化

由于大量的抗生素被用于畜禽养殖行业,畜禽养殖场中的抗生素抗性基因 (ARGs,Antibiotic resistance genes) 问题正逐渐变得严重。为调查畜禽养殖场中气载ARGs的污染特征及季节性变化,分别在冬季和夏季采集陕西省渭南市养猪场和养鸡场的空气和粪便样品,分析不同种类气载ARGs的污染水平及ARGs与环境因子的相关性。结果表明：畜禽养殖场空气中主要检出的ARGs类型为万古霉素类抗性基因、MLSB类抗性基因、四环素类抗性基因、FCA类抗性基因;在不同类型养殖场中气载ARGs总浓度趋势为养鸡场>养猪场,且养鸡场中每种ARGs浓度比养猪场中高约2个数量级;在不同季节养殖场中,气载ARGs总浓度趋势为冬季>夏季,且每种ARGs在冬季均高于夏季2~3个数量级。Pearson相关性分析结果表明,养殖场中气载ARGs总浓度与PM_2.5呈显著相关 (P<0.05) ,与其他环境因子无显著相关性。本研究成果可为控制畜禽养殖场中气载ARGs污染的传播及防控提供参考。     

Concentrations of additive arsenic in Beijing pig feeds and the residues in pig manure

The swine industry in China has grown rapidly over last two decades. Great amount of pig manure is generated in China, which can be used as organic fertilizers on agricultural lands. Meanwhile, the organic arsenic compounds have been used as feed additives for swine disease control and weight improvement. Once the excessive additives are released in the environment, arsenic may compromise food safety and environmental quality. There is a growing public concern about the arsenic residues accumulation in pig manure, however, little work has been done to investigate the exact arsenic content in pig feed and the residues in manure in China This study investigates the concentrations of arsenic in 29 pig feed samples and 29 manure samples collected from eight pig farms in the Chaoyang district, Beijing city. The detected rate of arsenic in 29 couples of samples was 100%. The concentrations of arsenic in pig feeds and manures ranged from 0.15 to 37.8 mg/kg and 0.42 to 119.0 mg/kg, respectively. The result showed that arsenic concentration in pig manure will be greatly elevated when the arsenic in pig feed was largely increased. The loading rates of pig manure in fourteen Beijing counties and districts were in the range of 2.7–57.2 t/ha yr. Accordingly, the potential soil arsenic increase rates resulting from land application of pig manure might range between 11.8 and 78.9 μg/kg yr. Despite these findings, it is too early to draw the conclusion that arsenic pollution from pig manure is serious in Beijing farmland; therefore, longitudinal studies about the chemical form transformation and the environmental behaviors of pig manure arsenic are required in order to come up with more definitive conclusions.     

吉林省畜禽养殖污染现状及防治对策

畜禽养殖污染问题已经越来越引起社会的关注。畜禽粪污处理不当会污染地表水及地下水,也会对土壤造成污染,养殖场恶臭对空气环境造成污染,使得畜禽传染病及寄生虫病等不断蔓延。通过详细调查分析吉林省畜禽养殖情况、畜禽粪污产生量和处理情况以及环境污染现状,提出吉林省畜禽养殖污染的防治对策,既需要加强畜禽养殖污染防治技术的研究,也需要研究必要的政策和加强管理,更需要开展必要的国际合作。以实现资源循环利用,促进吉林省畜禽养殖业健康发展。     

Vegetative buffers for fan emissions from poultry farms: 1. temperature and foliar nitrogen

This study sought to evaluate the potential of trees planted around commercial poultry farms to trap ammonia (NH₃), the gas of greatest environmental concern to the poultry industry. Four plant species (Norway spruce, Spike hybrid poplar, Streamco willow, and hybrid willow) were planted on eight commercial farms from 2003 to 2004. Because temperature (T) can be a stressor for trees, T was monitored in 2005 with data loggers among the trees in front of the exhaust fans (11.4 to 17.7 m) and at a control distance away from the fans (48 m) during all four seasons in Pennsylvania. Norway spruce (Picea abies) foliage samples were taken in August 2005 from one turkey and two layer farms for dry matter (DM) and nitrogen (N) analysis. The two layer farms had both Norway spruce and Spike hybrid poplar (Populus deltoides × Populus nigra) plantings sampled as well allowing comparisons of species and the effect of plant location near the fans versus a control distance away. Proximity to the fans had a clear effect on spruce foliar N with greater concentrations downwind of the fans than at control distances (3.03 vs. 1.88%; P ≤ 0.0005). Plant location was again a significant factor for foliar N of both poplar and spruce on the two farms with both species showing greater N adjacent to the fans compared to the controls (3.75 vs. 2.32%; P ≤ 0.0001). Pooled foliar DM of both plants was also greater among those near the fans (56.17, fan vs. 44.67%, control; P ≤ 0.005). Species differences were also significant showing the potential of poplar to retain greater foliar N than spruce (3.52 vs. 2.55%; P ≤ 0.001) with less DM (46.00 vs. 54.83%; P ≤ 0.05) in a vegetative buffer setting. The results indicated plants were not stressed by the T near exhaust fans with mean seasonal T (13.04 vs. 13.03°C, respectively) not significantly different from controls. This suggested poultry house exhaust air among the trees near the fans would not result in dormancy stressors on the plants compared to controls away from the fans.     

CFD simulation of pool fires situated at differing elevation

When two or more pool fires happen to burn so close to each other that they interact, they are termed ‘multiple pool fires’ (MPF). Past accident analysis reveals that MPFs occur quite frequently in chemical process industries. Controlled experiments done so far to study MPFs have indicated that MPFs lead to increase in the fuel burning rate, flame height and heat release rate (HRR) but the nature and the extent of the impacts of different factors on these manifestations is as yet poorly understood. In this context computational fluid dynamics (CFD) appears to be a tool which can enable more detailed and realistic simulation of MPFs than other possible approaches, especially due to its ability to closely approximate the underlying physical phenomena. In tank farms there are situations where different storage tanks are placed at different elevations yet close to each other. If such tanks happen to catch fire, the resulting fires may influence each other in a manner that may be a function of the difference in the tanks’ elevation. However no CFD study has been carried out which addresses this type of situation. Hence an attempt has been made to employ CFD to study MPFs involving two pools with fuel surfaces are at different elevations. Results reveal that good correlation is possible between the experimental findings and the CFD simulations.     

The role of NIMBY in opposing the siting of wind farms: evidence from Greece

This paper aims to assess the relative importance of a NIMBY (‘Not-In-My-Back-Yard’) stance on an individual's opposition to the siting of a wind farm vis-à-vis other predictors, such as perceived effects (costs, risks and benefits associated with the project), perceived fairness of the siting decision and societal trust. Data originate from two case studies, a small wind farm of just two wind turbines in southern Greece and a mega-project of 153 turbines on the Greek island of Lesvos (aggregate N = 334). We use structural equation modelling (SEM) for testing the theoretically-suggested relations between the various constructs. We find that NIMBY is not the most important predictor of opposition while it is strongly correlated with other predictors, such as the perceived unfairness of the siting decision as well as the risks and costs associated with the wind farm. These latter findings undermine the common-sense idea that wishing a wind farm out of one's vicinity (‘Not-In-My-Back-Yard’) is an example of mere ‘free-riding’. Since the fit of the SEM models was found to be moderate, we discuss the limitations of our study and the implications of our findings as well as suggesting pathways for future research.     

盐度、C：N对SBR工艺处理海水产品养殖场废水的影响

海水产品养殖场废水中碳、氮的浓度很高,通过序批式反应器（SBR）处理,能有效的降低碳、氮的浓度。在常温（20℃-25℃）条件下,我们检测了不同盐度、C：N下的处理效果,以期实现SBR工艺运行参数的最优化。实验结果表明：盐度为2．5％～3．5％,C：N为10：1的条件下,除碳和生物脱氮的效果最佳。实验验证了SBR工艺在海水产品养殖场废水处理中可以作为一个非常有效的处理手段而应用。     

Roles of pyrolysis on availability,species and distribution of Cu and Zn in the swine manure: Chemical extractions and high-energy synchrotron analyses

Animal manures generally contain high levels of heavy metals that may pose a significant threat to soil and groundwater qualities. Pyrolysis as means of reducing metal availability in such feed stocks is recently encouraged, but systematic studies are currently lacking. The aim of this study was to assess the impact of pyrolysis temperature on the availability of Cu and Zn by chemical extraction, to determine the speciation of Cu and Zn by synchrotron-based X-ray spectroscopy, and finally to investigate the phase distribution of metal species in the carbonaceous materials by combining acid–base extractions and absorption spectroscopy data. The results showed that both Cu and Zn in the swine manure were mainly bound to organic functional groups. Cu (II) reduction and Cu (I)–S complexes were observed during the pyrolysis process. Zn species resembling ZnAc₂ was still dominant, being 60.8–69.2%, and ZnS increased by 6.6–21.8% in the carbonaceous materials. The distribution of Cu and Zn in the mineral, carbonized and non-carbonized organic phases varied greatly with the pyrolysis temperature. The higher the temperature, the more the metals existed in the mineral phase and carbonized organic phase. The decrease of EDTA extractable Cu and Zn with pyrolysis temperature was due to the increase of metals in the carbonized organic phase and mineral phase. It is suggested that pyrolysis at the relatively higher temperature is a better choice for metal-containing manure according to the metal speciation, solubility and availability.     

Vegetative buffers for fan emissions from poultry farms: 2. ammonia,dust and foliar nitrogen

This study evaluated the potential of trees planted around commercial poultry farms to trap ammonia (NH₃) and dust or particulate matter (PM). Norway spruce, Spike hybrid poplar, hybrid willow, and Streamco purpleosier willow were planted on five commercial farms from 2003 to 2004. Plant foliage was sampled in front of the exhaust fans and at a control distance away from the fans on one turkey, two laying hen, and two broiler chicken farms between June and July 2006. Samples were analyzed for dry matter (DM), nitrogen (N), and PM content. In addition, NH₃ concentrations were measured downwind of the exhaust fans among the trees and at a control distance using NH₃ passive dosi–tubes. Foliage samples were taken and analyzed separately based on plant species. The two layer farms had both spruce and poplar plantings whereas the two broiler farms had hybrid willow and Streamco willow plantings which allowed sampling and species comparisons with the effect of plant location (control vs. fan). The results showed that NH₃ concentration h^{? 1} was reduced by distance from housing fans (P ≤ 0.0001), especially between 0 m (12.01 ppm), 11.4 m (2.59 ppm), 15 m (2.03 ppm), and 30 m (0.31 ppm). Foliar N of plants near the fans was greater than those sampled away from the fans for poplar (3.87 vs. 2.56%; P ≤ 0.0005) and hybrid willow (3.41 vs. 3.02%; P ≤ 0.05). The trends for foliar N in spruce (1.91 vs. 1.77%; P = 0.26) and Streamco willow (3.85 vs. 3.33; P = 0.07) were not significant. Pooling results of the four plant species indicated greater N concentration from foliage sampled near the fans than of that away from the fans (3.27 vs. 2.67%; P ≤ 0.0001). Foliar DM concentration was not affected by plant location, and when pooled the foliar DM of the four plant species near the fans was 51.3% in comparison with 48.5% at a control distance. There was a significant effect of plant location on foliar N and DM on the two layer farms with greater N and DM adjacent to fans than at a control distance (2.95 vs. 2.15% N and 45.4 vs. 38.2% DM, respectively). There were also significant plant species effects on foliar N and DM with poplar retaining greater N (3.22 vs. 1.88%) and DM (43.7 vs. 39.9%) than spruce. The interaction of location by species (P ≤ 0.005) indicated that poplar was more responsive in terms of foliar N, but less responsive for DM than spruce. The effect of location and species on foliar N and DM were not clear among the two willow species on the broiler farms. Plant location had no effect on plant foliar PM weight, but plant species significantly influenced the ability of the plant foliage to trap PM with spruce and hybrid willow showing greater potential than poplar and Streamco willow for PM_2.5(0.0054, 0.0054, 0.0005, and 0.0016 mg cm^{? 2}; P ≤ 0.05) and total PM (0.0309, 0.0102, 0.0038, and 0.0046 mg cm^{? 2}, respectively; P ≤ 0.001). Spruce trapped more dust compared to the other three species (hybrid willow, poplar, and Streamco willow) for PM₁₀ (0.0248 vs. 0.0036 mg cm^{? 2}; P ≤ 0.0001) and PM_{> 10} (0.0033 vs. 0.0003 mg cm^{? 2}; P = 0.052). This study indicates that poplar, hybrid willow, and Streamco willow are appropriate species to absorb poultry house aerial NH₃–N, whereas spruce and hybrid willow are effective traps for dust and its associated odors.