新鲜猪沼液和牛沼液对农作物病原真菌抑制作用的比较研究

本试验在实验室条件下,研究大中型沼气工程猪沼和牛沼两种沼液原液及其离心上清液对大豆尖孢镰刀菌、大豆菌核病菌、小麦纹枯病菌、小麦根腐病菌、水稻纹枯病菌、玉米大斑病菌和玉米小斑病菌等7种农作物病原真菌的抑制作用。结果表明：猪沼原液和牛沼原液对其中的大豆尖孢镰刀菌、大豆菌核病菌、小麦纹枯病菌、小麦根腐病菌和水稻纹枯病菌5种病原真菌具有较好的抑制作用,其菌丝生长抑制率均在72%以上,但对玉米大斑病菌和玉米小斑病菌的菌丝生长基本没有抑制作用;相比之下,猪沼和牛沼离心上清液对以上5种病菌的菌丝生长抑制作用明显减弱,除猪沼离心上清液对大豆菌核病菌的菌丝生长抑制率大于70%以外,试验中猪沼和牛沼离心上清液对实验病原菌的菌丝生长抑制率基本都在60%以下。试验结果显示猪沼液和牛沼液对农作物病原真菌具有潜在的植物病害防治作用,为养殖场大中型沼气工程沼液应用新技术的开发提供科学依据。     

Calcium CO-Amendments Modify Extractable Orthophosphate Levels in Fresh and Composted Cattle Manure

The Hong Kong Environmental ProtectionDepartment (HK EPD) monitoring data for SO₂, NO, NO₂and O₃ from 1995 and 1996 at three stations spanning thelength of Hong Kong have been analyzed in the contexts ofselected meteorological parameters, and the types of synopticweather system. High level and episode days were definedaccording to two criteria. Higher pollutant gas concentrationswere found for systems involving the transport of continentalair masses to Hong Kong (cold front (type CF), north/northeastmonsoon (type NE)), or when tropical cyclones approached (typeAC) Hong Kong. Lower concentrations were observed when thecleaner maritime southerly (type S) airstreams were incidentat Hong Kong. Most notably, tropical cyclones (type C)ventilated and diluted local pollution. Days with high levelsof SO₂, NO and NO₂ were generally characterized bylow windspeed and lower relative humidity conditions. Bycontrast, high concentrations of O₃ occurred both underlow windspeed conditions (type AC) and under the advection ofa continental air mass, generally at high windspeeds. Thediurnal variation of O₃ levels is discussed: destructionis more important than production in determining local levels.     

Characteristics of Nitrous Oxide (N2O) Emissions from Intermittently-Aerated Sequencing Batch Reactors Treating the Separated Liquid Fraction of Anaerobically Digested Pig Manure

In this study, the N₂O emission from an intermittently aerated sequencing batch reactor (IASBR-1) treating the separated liquid fraction of anaerobically digested pig manure (SLAP) was investigated. The wastewater had chemical oxygen demand (COD) concentrations of 11,540?±?860?mg?l^?1, 5-day biochemical oxygen demand (BOD₅) concentrations of 2,900?±?200?mg?l^?1and total nitrogen concentrations of 4,041?±?59?mg?l^?1, with low COD:N ratios (2.9, on average) and BOD₅:N ratios (0.72, on average). Synthetic wastewater, simulating the SLAP with similar COD and nitrogen concentrations but with higher BOD₅ concentrations of up to 11,500?±?100?mg?l^?1, was treated in another identical reactor (IASBR-2) to compare the effects of carbon source on nutrient removals and N₂O emissions. In steady-state, soluble N₂O accumulated in the non-aeration periods, with the highest N₂O concentrations measured at the end of the non-aeration periods. There was a significant reduction in N₂O concentrations during the aeration periods with reductions occurring immediately on commencement of aeration. The mean N₂O emissions in an operational cycle were 253.6 and 205.3?mg for IASBR-1 and IASBR-2, respectively. During the non-aeration periods, only 8.3% and 8.4% of total N₂O emissions occurred in IASBR-1 and IASBR-2, respectively; while during the aeration periods, 91.7% and 91.6% of N₂O emissions took place in IASBR-1 and IASBR-2, respectively. The mean specific N₂O generation rates were 0.010 and 0.005?mg (g VSS·min)^?1 in the aeration periods, 0.024 and 0.021?mg (g VSS·min)^?1 in the non-aeration periods for IASBR-1 and IABSR-2, respectively. Mean nitrogen removal via N₂O emissions was 15.6% and 10.1% for IASBR-1 and IASBR-2, respectively. The IASBR-1 with low influent BOD₅ concentrations emitted and generated more N₂O.     

Fate and Transport of Organic Compounds in Municipal Solid Waste Compost

Four chemicals, polychlorinated biphenyls (PCB), benzo(a)pyrene (B(a)P), a-chlordane, and bisethylhexyl phthalate (BEHP), were chosen for investigation because of their range of physical/chemical properties and because they have been reported in municipal solid waste compost in the literature. Field studies were performed by applying amended compost, which was spiked with the four chosen organic chemicals, into corn, fescue, and poplar fields in Amana, Iowa.

The Pesticide Root Zone Model II (PRZM II), a U.S. EPA computer code (Dean, et al., 1989), was utilized to predict the potential fate and transport of four chemicals in the unsaturated zone. Model input consisted of meteorological records from nearby weather stations, soil data from the Amana site and laboratory results/literature values of chemical properties.

Results indicate that, due to their relatively low solubility and high hydrophobicity, the chemicals are quite sorptive to the soil/compost mixture and barely migrate vertically in the soil. In five year simulations, the chemicals remained within the rooting zone of the plants and slowly biodegraded. Plant uptakes were relatively small and essentially no leachate reached the groundwater table. Volatilization of PCB and chlordane was significant only for the top soil layer. A field study is being used to verify the modeling results.     

Stabilization of Preliminary Anaerobically Digested Slurry in Post-Storage: Dynamics of Chemical Characteristics and Hygienic Quality

Dynamics of chemical characteristics and hygienic quality, particularly nutrients, heavy metals, and bacterial pathogens, were investigated along the storage of anaerobically digested slurry derived from chicken and pig manure. The average total solid (TS) content decreased by 3.6 and 24.1%, while soluble chemical oxygen demand (SCOD) decreased by 23.7 and 31.4%, in chicken manure- and pig manure-digested slurries storage, respectively. A rapid increase in NH₄ ⁺-N concentration from 1600 to 4800 mg/L in chicken manure-digested slurry and from 1200 to 1700 mg/L in pig manure-digested slurry was noted, particularly during the first 10 days of storage. A positive correlation between TS and content of heavy metals (Cu, Zn, Cr, and Pb) in the digested slurry was clearly shown. These metals are mainly associated with suspended particles and tend to be settled in the bottom during the storage process. Increasing attention should be paid to the land application of these bottom-settled digestates with higher TS content. The number of total coliforms and Escherichia coli in the both digested slurries decreased continuously during the whole storage period. The higher reduction rate observed during the storage of chicken manure-digested slurry may be due to the higher content of NH₄ ⁺-N, which may cause the inhibition of gram-negative bacteria. The results of this study provides a better understanding of the storage process of anaerobically digested slurry, which could benefit the digested slurry further utilization as agriculture fertilizer.     

Comparative Composition of Volatile Organic Compounds in the Water-Soluble Fraction of Different Crude Oils Produced in Kuwait

Kuwait's desert was inundated, in 1991, with massiveoil-spills from damaged well heads and from oil fires.Large volumes of seawater used for fire-fightingfreely mixed with oil and then seeped into the ground.The dissolved compounds not only contaminated soil butalso threaten to pollute groundwater. The compositionof the volatile organic compounds (VOCs) in thewater-soluble fraction (WSF), in seawater, of tendifferent crude oils produced in Kuwait and Kuwaitcrude oil (export) was investigated. The resultsshowed that the composition of the WSFs variedconsiderably (ranging from 5970 μg L^-1 to10494 μg L^-1). On average, about 40 volatilecompounds were identified and quantified in the WSFs.Aromatics formed the bulk of the WSF of all of thecrude oils, amounting to about 90% of the total VOCs.The WSF prepared from Raudatain crude oil containedthe highest total VOCs (benzene and toluene) whilethat of Um-Ghadair contained the lowest. The WSF ofKuwait crude oil (export) was compared with that ofindividual oils and was found to contain relativelysmaller amounts of individual components and the VOCs.Relatively higher amounts of toxic VOCs in the WSF ofRaudatain crude oil has potential to impact the fonaand flora as well as potable ground water in the area.     

Biological Elimination of Volatile Organic Compounds from Waste Gases in a Biofilter

A great deal of research has been directed towards the problem of reduction and control of volatile organic compounds (VOCs). The aim of this research is to find a process that is both efficient and inexpensive in comparison with traditional air treatment technologies. Our biofilter (one stage system, 2 m in height) is an aerobic system for waste gases containing VOCs using the degradation properties of microbial flora (assorted cultures of Bacillus, Micrococcus, Acinetobacter and yeast). In this process, polluted gas diffuses across a filter bed into which a microbial culture has previously been introduced. Peat is the medium of choice for inoculation with microorganisms because of its adsorption and absorption properties, ability to retain moisture, and buffering capacity. Furthermore, the peat utilized is spherical in shape; thus, it is possible to avoid problems related to compacting. The objective of this study was to eliminate VOCs emitted from a rotogravure process. We were able to achieve promising results from biofiltration of two types of VOCs (a mixed solvent containing isopropyl acetate and 1-nitropropane, and the solvent: 1-nitropropane). The results obtained indicate that the elimination of nitropropane and the mixed solvent in the biofilter are considered to follow zero-order kinetics with reaction rate limitation and diffusion rate limitation, respectively.     

添加造纸白泥对猪场废水厌氧消化液中氮磷回收的影响

以造纸废弃物白泥作为pH调节剂,利用MAP沉淀法回收厌氧消化液中的氮磷,并采用曝气的方式提高消化液pH值和造纸白泥的溶解性,研究了造纸白泥的添加量和曝气时间对厌氧消化液中氮、磷回收效果的影响,并考察了曝气过程中pH、COD、PO34--P、NH3-N、Mg2＋、Ca2＋的变化规律。结果表明造纸白泥的添加量为8g.L-1,曝气时间为120min时,PO34--P和NH3-N的回收率分别达到98和59,出水的PO34--P和NH3-N浓度分别为0.98mg.L-1和60.66mg.L-1,均达到了《畜禽养殖业污染物排放标准》（GB18596—2001）的要求,同时,COD的去除率为45;如果仅用曝气方式处理,120min后PO34--P和NH3-N的回收率仅分别为66和41,均未达到排放标准要求。可见,与仅用曝气方式处理相比,添加造纸白泥协同曝气对厌氧消化液中氮磷的回收有明显的效果。     

Spatial Variability of Soil Organic C,Inorganic N and Extractable P in a Mediterranean Grazed Area

In this paper, we studied the spatial variability of soil organic C (SOC), inorganic N (SIN) and extractable P (P_extr) in a grazed Mediterranean‐type vegetation formation. Sampling was conducted from a gently sloping area in northern Greece.. The grazing pressure was evenly distributed over the experimental area with the exception of an overgrazed passage zone 200–300 m from steeper foothills. Soil samples, from the upper 10 cm, were collected every 10 m along four replicate lines (400 m length with a distance of 10 m between lines). Sampling took place twice (October and February). Data were analysed by geostatistical tools, and spherical models were significantly fitted to the semivariograms. SOC in both samplings and SIN in the first one displayed moderate spatial dependence which indicates the non‐random distribution of their concentration. On the contrary, P_extr and SIN in winter exhibited weak spatial dependence, whereas P_extr in autumn showed spatial independence. For the parameters exhibiting spatial pattern, two scales of dependence were revealed: a fine scale within distances shorter than 10 m and a coarse scale varying between 80 and 130 m. The coarse distribution of SOC, SIN and P_extr invoked interplay among more predictable (composition of vegetation) and unpredictable (leaching, runoff) extrinsic factors, occurring at the landscape level. Specifically, SOC as a storage agent exhibited uniform spatial pattern in both samplings. By contrast, SIN by being susceptible to leaching exhibited time‐specific dependence, whereas P_extr which was affected by surface runoff displayed limited or even spatial independence. Copyright © 2012 John Wiley & Sons, Ltd.     

Immobilization of Mercury Species under the Influence of Typical Organic Compounds in Waste Gases by the Circulating Fluidized Bed

Hearth furnace coke (HOK), a special type of lignite (brown-coal)coke produced in a manufacturing process called `hearth furnace process', and portlandite (Ca(OH)₂) particles were placed ina circulating fluidized bed reactor. Defined model waste gases containing HCl/SO₂/Hg⁰/Hg²⁺ and organic compounds were injected into the reactor to investigate the adsorption of different mercury species. Elemental mercuryreacted immediately with HCl to form HgCl₂, but for Hg²⁺ further investigations had to be made, because todaygas cleaning plants still have problems in observing national limits for the mercury output. The temperature, the mercury content of the gas, and its content of acid compounds as majorinfluences in cleaning exhaust gases were varied without relevantpositive effects on the adsorption rate which decreased from nearly 100% in the first five minutes to unsatisfactory20% some minutes later. The mercury load on the HOK particles onlyshowed a value of 60 μg Hg g^-1 HOK. Then organic compounds (guide pollutants such as 1-chlorobutane, monochlorobenzene, toluene, and naphthalene, which are alwayspresent in incineration plant exhaust gases) were added to thegas stream and the results improved significantly. The mercuryload on the HOK particles varied depending on the chemical nature of the organic compound and amounted to 300 μg Hg g^-1 HOK maximum. The measured values of mercury in the clean gas stream fell below 10 μg m^-3. The characterization of the dynamic behavior of mercury in hot, acid waste gases and the analytical identification of mercurysticking to HOK under the influence of organic compounds leadto new methods for improving the effectiveness and performanceof gas cleaning plants.     

Enhanced Reduction of Extractable Polychlorinated Biphenyls and Toxicity in Sediment by Organic Matter

Water, Air, & Soil Pollution - Aquatic system contamination is a subject of concern due to the high number of contaminants with the potential to be hazardous for plant and animal species,...     

Volatile Organic Compounds in the Ambient Air of Rousse,Bulgaria

Volatile organic compounds in the ambient air were measured at four locations in Rousse, Bulgaria for a one year period. A gas chromatograph/mass spectrometer equipped with a cryogenic concentrator was used to analyse the air samples. Forty one compounds (aromatic hydrocarbons and halogen-derivatives of aliphatic and aromatic hydrocarbons) were analysed by EPA method TO-14. Aromatic hydrocarbons, benzene, toluene, styrene, isomers of xylene and isomers of trimethyl benzene were the most frequently occurring pollutants. Styrene, isomers of xylene and isomers of trimethyl benzene frequently exceeded the concentration limits. Among the halogen derivatives, the concentration of chloroform was always very high. A concept called ‘degree of pollution’ was proposed to clarify the contribution of each pollutant to the total air-pollution. Suggestions were made on the need to introduce an integral tolerance parameter to describe the total impact on air-pollution.     

三江源退化高寒草原土壤有机碳组分分布研究

在青海省三江源区选择了玛多县花石峡镇高寒草原典型样区,划分5种不同退化程度样地(原生植被UD、轻度退化LD、中度退化MD、重度退化HD、极度退化ED),10 cm等深度采集表土土壤样品,分析土壤有机碳和组分含量变化。结果表明,研究区内高寒草原土壤表土有机碳及组分含量随退化程度加剧和土层加深呈显著下降。与原生植被相比,轻度退化、中度退化、重度退化和极度退化下0~30 cm土层土壤有机碳含量分别平均降低了19.4%、44.4%、67.0%和79.7%,土壤轻组有机碳含量分别平均降低了14.4%、46.8%、68.9%和81.3%,土壤重组有机碳含量分别平均降低了21.1%、43.6%、66.4%和79.1%。轻组占有机碳含量的比例为20.45%~29.02%,重组占有机碳含量的比例为70.98%~79.55%,有机碳含量的分布主要集中在重组。总的来看,表层土壤有机碳及组分含量在生态系统退化下的变化最剧烈。随退化程度加剧,高寒草原土壤有机碳含量下降迅速,损失严重。保护高寒草地生态系统,对于三江源区畜牧业可持续发展和我国陆地生态系统碳库具有极重要的意义。     

Optical Properties of the Extractable Organic Matter Fractions in Typical Chernozems of Long-Term Field Experiments

Eurasian Soil Science - The extractable fractions of organic matter (OM) differing in their mobility—water-extractable organic matter, labile humic substances, and humic substances—have...     

Growth of Date Palm (Phoenix dactylifera L.) in Composts of Olive Oil Mill Waste with Organic Household Refuse

This study highlights the effects of composts of olive mill wastes and organic household refuse with a pH range of 7 to 7.98 and a C/N ratio between 14.9 and 22, to improve the growth and the mineral nutrition of the date palm (Phoenix dactylifera L.). After 7 months of cultivation, plants amended with composts showed higher biomass production than the controls. Compost C1, i.e., the basic compost with no additives phosphate, at 100% and 45% doubled the production of dry matter in comparison with control plants. The rise of root biomass was considerably greater for plants grown with compost C1 without phosphate. In contrast, the shoot biomass was highly significant for composts C2 and C3 enriched with phosphate. The control plants, grown without amendment, showed significantly higher specific root length (SRL) and specific leaf length (SLL). The efficiency of compost application was reflected by the biomass rise, the number of emerged leaves (2.6–4), and the rise in leaf area (3.3 to 6.7 cm²) by improving the mineral nutrition of the date palm. The composts of olive mill waste and organic household refuse supplemented with natural rock phosphate, or not, generated a notable agronomic added value.     

太湖流域农村生活垃圾产排污系数测算研究

选取太湖流域典型农村9户农户（高、中、低收入水平各3户农户）作为研究对象,采用现场监测及入户调查的方法对农户生活垃圾污染物产排系数进行为期一年的系统定量研究,结果表明：收入水平对农户总垃圾、有机垃圾、有机垃圾TN、TP产排污系数及可回收垃圾产污系数影响极显著（P〈0.01）,具体表现为高收入农户〉中收入农户〉低收入农户,但对农户有害垃圾产排污系数及可回收垃圾排污系数无显著性影响（P〉0.05）。因此,除有害垃圾产排污系数及可回收垃圾排污系数外,农户总垃圾、有机垃圾、有机垃圾TN、TP产排污系数及可回收垃圾产污系数可按收入水平划分。各收入水平农户有机垃圾占总垃圾比例超过80%,表明有机垃圾的综合利用效率特别是畜禽养殖率是影响生活垃圾污染物排放系数的主导因素,而农业收入水平则对这种因素影响显著。     

Growth of Rudbeckia and Leaching of Nitrates in Potting Media Amended with Composted Coffee Processing Residue,Municipal Solid Waste and Sewage Sludge

Composts made from coffee processing residue (CFPR), source separated municipal solid waste (MSW), sewage sludge and wood chips (SSWC), and sewage sludge, wood ash, wood chips and leaves (SSACL) were examined as replacements for the peat, perlite and sand found in a conventional potting medium. The perennial flower Rudbeckia hirta L. ‘Goldilocks’ (Black-Eyed Susan) was grown in media composed of 0, 10, 25, 50, 80, and 100 (percent by vol) of each compost. Leachate from media containing 0, 25, 50, and 100% compost was tested for NO₃-N and NH₃-N + NH₄-N to determine if compost would increase the potential for potting media to be a source of nitrate in surface and ground water. The effects of two mid season applications of liquid fertilizer on plant growth and nitrogen leaching were also examined.

Compared to a conventional medium without compost, differences in the growth of Rudbeckia in media with compost were few. Statistically significant decreases in growth occurred in media containing 80 and 100% CFPR, and 80% SSACL. None of the composts caused a statistically significant increase in growth. Leaching of nitrogen increased from media containing 100% CFPR, SSWC and SSACL compared to the medium with no compost. Media containing 25, 50, and 100% MSW leached less N the conventional medium. Liquid fertilizer did not significantly change the growth of Rudbeckia or the amount of nitrogen found in the leachate from any medium.     

Nitrogen Mineralization in Soils Related to Initial Extractable Organic Nitrogen: Effect of Temperature and Time

An important source of nitrogen (N) for crops is mineralization of soil organic matter during the growing season. Awareness is growing that dissolved organic nitrogen (DON) plays an important role in mineralization and plant uptake. We studied the influence of temperature and time on extractable organic nitrogen (EON) levels, which is a measure of DON, and their relationship with N mineralization. Aerobic incubation experiments were conducted in the laboratory for five soils at different temperatures (4 20, and 30 °C) and different time intervals with optimal water content (60% of its water-holding capacity). Net N mineralization ranged between 14 and 155 mg kg^–1 within 84 days and was correlated with the initial amount of EON. Net N mineralization among the soils, time, and incubation temperatures was linearly related to the square root of time multiplied by temperature, with mineralization rate k being independent of time and temperature. Because initial EON values were also related to these kvalues, we were able to describe the net N mineralization at different temperatures based on an analysis of initial EON. Preliminary validation with results from pot experiments in the literature suggests that the approach is promising, although the proposed model needs to be calibrated with more soils.     

低分子量有机酸对石灰性土壤有机磷组成及有效性的影响

为探索提高土壤磷素有效性的途径,采用室内培养的方法,研究不同有机酸对土壤速效磷含量及有机磷组分的影响。结果表明,添加有机酸后土壤速效磷含量发生显著变化,其中草酸处理下土壤速效磷含量显著高于其他处理,而柠檬酸和苹果酸对土壤速效磷含量具有抑制作用,其活化量为负值;随着培养时间的延长,速效磷含量缓慢降低。速效磷含量随着草酸浓度的升高而升高,随着苹果酸、柠檬酸浓度的升高而降低;有机酸处理后,土壤活性、中活性、中稳性有机磷升高,高稳性有机磷降低,这说明有机酸能促进土壤有机磷由有效性低的形态逐步向有效性高的形态转化,其中草酸的作用效果总体上较柠檬酸和苹果酸强。