猪粪堆肥中水分散性胶体的重金属分布研究

对猪粪有机肥中胶体态重金属的分布进行了定量分析。结果表明,水提取态Cu、Zn、Fe、Mn主要以胶体态存在,Ni、Cr、Cd、As几乎都以可溶态存在。胶体态Cu在0.02~0.2μm胶体中的含量最高,胶体态Zn、Fe、Mn在粒径为1~10μm的大粒径胶体中含量最高。在长期连续施用有机肥引起重金属积累的土壤中,高Cu负荷的小粒径胶体可能会引起深层土壤中重金属积累问题,胶体态有机碳与可溶态有机碳对重金属结合能力的不同可能是导致重金属分布存在差异的重要原因。重金属在不同粒径的分布特征可以为讨论猪粪有机肥中的重金属在环境中的化学行为提供论据。     

Sequentially Extracted Arsenic from Different Size Fractions of Contaminated Soils

Five soils from Austria that have high contents of arsenic (As)due to anthropogenic and/or geogenic sources were separated intosand, silt, and clay fractions. The distribution of As among theparticle-size fractions was clay >> silt > sand. Theparticle-size fractions were analysed according to an 8-stepsequential extraction procedure (SEP) designed to assess theprimary reservoirs and extractability of As. Steps 1 and 2,(i.e. NH₄NO₃ and (NH₄)₂SO₄) extractedthe least As, while considerably greater amounts were extractedin steps 3, 4 and 5 (i.e. NH₄H₂PO₄,NH₂OH-HCl, and NH₄F). The greatest amounts of As wereextracted in steps 6 and 7, both NH₄-oxalate extractantstargeting the amorphous and crystalline oxide fractions. Theresidual fraction (step 8) was typically low. The extraction ofthe clays contained generally more As in steps 3 to 8, while Asrelease in the first two steps was typically highest in the sandand silt fractions. These findings are in accord with factoranalysis indicating that the extractants of the SEP areseparated into weak (steps 1 and 2) and strong (steps 3 to 8)extractants. SEP data along with microprobe analyses (X-raymicroanalyses) indicate that most As is associated with Fe andis therefore not readily mobile. Anyhow, As could be releasedupon changes in redox potential or pH. The greaterextractability of As from sand fractions using weak extractantsmay explain the higher toxicity of As in coarse-textured soils,as found in previous studies.     

Wheat Proteins Extracted from Flour and Batter with Aqueous Ethanol at Subambient Temperatures

Contact of wheat flour with aqueous ethanol may enrich protein by starch displacement or deplete protein by extraction depending on 1) extraction conditions and 2) the form of the substrate. Extraction at subambient temperatures has not been described for specific gliadins for either dry flour with the protein in native configurations or for wet, developed batter or dough. This limits the ability to interpret technologies such as the cold-ethanol method. Here, we describe specific albumin and gliadin composition of flour extracts by capillary zone electrophoresis CZE in 0–100% (v/v) ethanol from –12 to 22°C. Extraction was reduced for albumin and gliadin protein as the temperature was reduced and the concentration range for extraction narrowed. Extraction dropped precipitously between 0 and –7°C for both albumins and gliadins. Electrophoretically defined gliadins extracted in constant proportion at 22°C and 30–80%(v/v) ethanol, but at lower temperature, the α-gliadins were enriched and β-gliadins depleted in the 30–55% (v/v) range. For extracts from wheat flour batter, depletion of α and β and enrichment of γ relative to the dry flour contact suggested that the electrophoretically slow migrating γ- and ω-proteins are less well incorporated to the dough matrix than electrophoretically fast migrating α and β types.     

Nitrous Oxide and Carbon Dioxide Emissions from Vietnamese Soil Amended with Different Compost Types at High Temperature

This study aims to determine the effects of compost additions and high temperature on N₂O and CO₂ emissions from a Vietnamese agricultural soil. Soil samples amended with two compost types (commercial compost, SH and chicken compost, CC) at three rates of 1%, 2% and 4% w/w were aerobically incubated at 25°C, 30°C and 35°C for 28 days in the laboratory. N₂O and CO₂ emissions were determined on days 1, 3, 5, 7, 14, 21 and 28. Our results showed that N₂O and CO₂ emissions were significantly affected by temperature, compost additions, and their interactions. Greater N₂O and CO₂ emissions were seen in CC treatments than SH treatments. Higher application rates of CC led to greater N₂O and CO₂ emissions. In SH treatments, higher temperature lowered N₂O emissions but did not affect CO₂ emissions. N₂O and CO₂ emissions were enhanced with CC addition while they showed different responses to increasing temperature.     

DDT Resistance and Transformation by Different Microbial Strains Isolated from DDT-Contaminated Soils and Compost Materials

Bioremediation is a potential option to treat 1, 1, 1-trichloro-2, 2-bis (4-chlorophenyl) ethane (DDT) contaminated sites. In areas where suitable microbes are not present, the use of DDT resistant microbial inoculants may be necessary. It is vital that such inoculants do not produce recalcitrant breakdown products e.g. 1, 1-dichloro-2, 2-bis (4-chlorophenyl) ethylene (DDE). Therefore, this work aimed to screen DDT-contaminated soil and compost materials for the presence of DDT-resistant microbes for use as potential inoculants. Four compost amended soils, contaminated with different concentrations of DDT, were used to isolate DDT-resistant microbes in media containing 150 mg l^?1 DDT at three temperatures (25, 37 and 55°C). In all soils, bacteria were more sensitive to DDT than actinomycetes and fungi. Bacteria isolated at 55°C from any source were the most DDT sensitive. However DDT-resistant bacterial strains showed more promise in degrading DDT than isolated fungal strains, as 1, 1-dichloro 2, 2-bis (4-chlorophenyl) ethane (DDD) was a major bacterial transformation product, while fungi tended to produce more DDE. Further studies on selected bacterial isolates found that the most promising bacterial strain (Bacillus sp. BHD-4) could remove 51% of DDT from liquid culture after 7 days growth. Of the amount transformed, 6% was found as DDD and 3% as DDE suggesting that further transformation of DDT and its metabolites occurred.     

水稻秸杆腐解过程溶解性有机质红外光谱研究

采用傅里叶红外光谱(FTIR)分析方法研究了水稻秸杆不同腐解阶段产生溶解性有机质(dissolvedorganic matter,DOM)及其分组组分的结构特征.结果表明,水稻秸杆腐解过程中DOM组成成分的变化呈现出明显的阶段性.在第0～3天,秸杆本身含有的糖类、氨基酸等小分子物质因微生物繁殖迅速消失;第3～ 63天,主要是秸杆中的半纤维素、纤维素的分解阶段,DOM组成中多糖类、烷烃类物质呈现起伏性变化;第63天后,主要是腐殖化阶段,DOM分子结构复杂化.各分组组分的结构特征有明显差异,且各组分均随腐解延长而发生变化,即多糖类物质减少,芳香族物质增多,分子结构复杂化.     

不同温度条件下沙棘雄株花粉储存时间研究

为研究不同温度条件、不同储存时间对沙棘雄株花粉生活力的影响,采用蓝墨水染色法对分别保存在20～22℃室温和4℃低温条件下的沙棘雄株花粉离体后的生活力进行了测定。结果表明:室温下无刺雄花粉存活时间最短,活性下降速度最快,离体5～11 d下降速度达到峰值,中雄花粉存活时间最长,活性下降速度最慢,11～15 d下降速度到达峰值,以花粉生活力50%为下限,阿列伊与201306可以存活9 d,中雄可以存活11 d,无刺雄存活7 d;4℃低温条件下,阿列伊花粉存活时间最长,为17 d,活性下降速度最慢,在离体15～21 d时下降速度达到峰值,无刺雄花粉存活时间最短,为9 d,活性下降速度快,在5～11 d时下降速度达到峰值,中雄与201306花粉存活时间分别为13、11 d。     

不同热解温度制备的水稻秸秆生物炭理化特性分析

以不同热解温度(100～800℃)制备的水稻秸秆生物炭为研究对象,研究在不同热解温度下制成的生物炭的理化特性。结果表明,热解温度为100～300℃制成的水稻秸秆生物炭呈弱酸性,400℃以上时呈碱性;水稻秸秆生物炭表面碱性含氧官能团数量随着热解温度的升高而增加、酸性含氧官能团则减少;水稻秸秆生物炭中的官能团C=C、C-O-C、-OH和-C=O在较高的热解温度下发生缔合或消除,促进了芳香基团的形成;随着热解温度的升高,水稻秸秆生物炭的阳离子交换量(CEC)、比表面积、孔径、比孔容、氮气吸附量和颗粒表面的分型维数(D1)均先增加后降低,阳离子交换量(CEC)在300～500℃时、其它性状在400～600℃之间达到最大值;以不同热解温度制成的水稻秸秆生物炭颗粒的孔隙结构均以孔隙宽度2～50 nm的中孔为主。随热解温度的升高,水稻秸秆生物炭的产率逐渐降低;400～500℃炭化2 h,生物炭产率最高,其孔隙结构最为复杂,所以可以认为400～500℃是水稻秸秆炭化的最佳温度。     

Granulometry of Non-colloidal Particulate Matter Transported by Urban Runoff

Water, Air, & Soil Pollution - This study examined the granulometry of non-colloidal particulate matter (PM) from four urban transportation land use catchments (source areas) in Baton Rouge,...     

Insights into Sorghum Starch Biosynthesis from Structure Changes Induced by Different Growth Temperatures

The effects of high growth temperature on sorghum starch structures were examined from the grains of three inbred lines (BTx623, IS8525, and Karper669), and the possible mechanism by which the growth of amylopectin molecules is terminated was discussed. Sorghum plants were grown at high temperature (38/21°C day/night) and control temperature (32/22°C day/night) from sowing to maturity. The grains sampled from plants grown at high temperature had significantly lower starch weights per grain (except BTx623) and smaller starch granule sizes than those grown at control temperature. Nevertheless, the amylose contents were similar. BTx623 and IS8525 samples grown at high temperature also had higher ratios of long to short amylopectin branches and lower degree of branching than their control counterparts. These results suggested that the activities of starch biosynthetic enzymes were evidently affected by elevated growth temperature. However, the weight‐average molecular weight and the z‐average radius of gyration of sorghum starch molecules were not significantly affected by the growth temperatures, suggesting that the effects of growth temperature on starch yield, starch granule size, and the branching structure of amylopectin molecules did not influence the events that stopped the overall growth of amylopectin molecules. This observation was consistent with the cessation of whole‐molecule growth being through increasing hindrance to enzyme access as the size of the starch molecule increases, controlled largely by the molecular density of the outermost part of an amylopectin molecule.     

Microbial Utilization and Transformation of Humic Acids Extracted from Different Soils

Humic acids (HA) extracted from Chernozem (Haplic Phaeozem), Brown Earth (Cambic Umbrisol) and Podzol (Humic Podzol) were added as a supplemental source of nutrients, or as the sole sources of carbon and nitrogen to aerobic cultures of complex microbial communities indigenous to the same individual soils. Depending on nutrient conditions in the individual cultures and origin of HA, between 14 and 86 % of the added HA was utilized. The formation of microbial biomass was enhanced up to six fold in the full-strength nutrient media supplemented with humic acids but was strongly inhibited if HA served as the sole C source. HA preparations re-isolated from the microbial cultures exhibited elemental and structural changes characteristic for early diagenetic transformations of humic substances. These included an increase in carbon content, C:N ratio, infra-red absorption typical for aromatics, and a decrease in infra-red absorption associated with aliphatic acids, nitrogenous and carbohydrate-like substances.     

不同利用方式下黄泥土中胡敏酸对芘的吸附特性初探

采用高效液相色谱法测定三种不同利用方式下黄泥土中胡敏酸对芘的吸附效应。结果表明:桑园、水田、水杉土壤中胡敏酸对芘的吸附在低浓度范围近似线性,而浓度较高时,吸附曲线的非线性增强,三者呈现相似的非线性吸附。但是,十年时间的不同利用方式对土壤中胡敏酸元素组成影响较小,桑园、水田、水杉土壤中胡敏酸对芘的吸附分配系数有一定差别,说明不同胡敏酸对芘的吸附能力不同,必然与其组成结构有关。不同利用方式下黄泥土中胡敏酸对芘的吸附等温线用Freundlich等温方程拟合效果很好,均达到显著相关。     

Characterization of Compost Leachate Fractions Using NMR Spectroscopy

A distilled water leachate was prepared from a hardwood-leaf compost. The ¹³C NMR (nuclear magnetic resonance) spectra of organic acids isolates from this leachate provided support for the hypothesis that the composition of the dissolved organic carbon (DOC) in the leachate is very similar to that in natural soil pore waters. The leachate DOC was adsorbed by a model mineral surface, and the organic coating on the surface was characterized by solid-state ¹³C NMR spectroscopy.     

Characterization of Fungal Biodiversity In Compost and Vermicompost

The ability of fungi to break down complex carbon sources makes them of vital importance in both the generation and application of compost. This paper illustrates the diversity and functions of the mycoflora of both a green compost (made solely thermophilically from plant debris) and a vermicompost (made mesophilically by the action of earthworms on plant and animal wastes). The soil dilution plate technique was applied on 3 media (PDA, CMC, PDA plus cycloheximide) and at 3 incubation temperatures (24°C, 37°C and 45°C) to isolate and identify fungal entities. Enzymatic activities (amylase, cellulase, chitinase, esterase, ligninase, pectinase, phosphatase, plastic degradation and xylanase) of most species from both composts were evaluated with a semiquantitative method on 15 substrates. There were substantial qualiquantitative differences in the species composition of the two composts. A total of 193 entities were isolated: 54 from green compost only, 77 from vermicompost only, 62 from both. This taxonomic diversity was reflected in the metabolic potential. Amilase, cellulase, protease and esterase activities were significantly higher in the green compost. Lignin and plastic polymer degradation were significantly higher in the vermicompost. Structural and functional characterization of this kind is of assistance in determining both the most appropriate application of composts and their hygienic quality.     

The Size of P Pools in Soils is Affected by Soil Properties and Compost Addition

It is well known that compost amendment can improve soil phosphorus (P) availability, but there are few studies comparing the effect of one compost type on soil P pools of soils which differ in properties. The aim of this glasshouse experiment was to determine the effect of compost (derived from garden waste) application on P pools in soils with different properties planted with wheat. Four soils from two sites were used, with a heavier and a lighter textured soil from each site. The compost was applied as a 2.5 cm thick layer on the soil surface and wheat plants were grown for 63 days. The treatments also included soil without compost and plants. All pots were regularly watered. The soils were sampled on day 0 in the unamended soils and on day 63 in soil without compost and with compost, and plants after removal of the compost layer. Without and with compost the concentrations of most P pools were higher in the two heavier textured soils (16% and 35% clay) than in the two lighter textured soils (8% and 13% clay). Principal component analysis (PCA) showed that the concentrations of most P pools were positively correlated with organic matter, clay, and silt content of the soils. Only the concentration of water-soluble P was positively correlated with sand content. Compost addition increased the concentration of microbial P, sodium bicarbonate (NaHCO₃)-Pi, sodium hydroxide (NaOH)-Pi, hydrochloric acid (HCl)-P, and residual P in all soils, whereas the concentration of NaHCO₃-Po was reduced and the concentration of NaOH-Po little affected by compost addition indicating that P was transferred from the compost layer with watering. Compared with the unamended soil on day 0, the concentrations of microbial P, NaHCO₃-Pi, NaOH-Pi, HCl-P, and residual P on day 63 were higher, whereas the concentrations of the two organic pools (NaHCO₃-Po and NaOH-Po) were lower. This suggests mineralization of organic P pools and formation of inorganic P as well as microbial P uptake. These changes occurred in the unamended and compost-amended soils with greater increases over time in the compost-amended soils. It can be concluded that the size of the P pools is predominately affected by soil texture. Compost amendment increases P availability and microbial P uptake but also leads to the formation of less labile P pools such as HCl-P and residual P which could serve as plant P sources in the long term.     

不同分辨率DEM提取切沟形态特征参数的转化研究

选取黄土丘陵区岔巴沟流域不同位置和不同沟道级别的30条典型切沟为研究对象,基于三维激光扫描技术(LIDAR),建立了基于高分辨率DEM提取切沟形态特征的方法,对比分析了0.1m与5m2种分辨率DEM提取切沟形态特征参数的差异,实现对低分辨率DEM提取的切沟形态特征参数向高分辨率尺度转化。结果表明:基于三维激光扫描技术获取的0.1m高分辨率DEM提取的切沟形态特征值与手工测量的切沟形态特征值之间无显著差异,三维激光扫描技术提取的切沟长度、宽度、深度、表面积和体积分别是手工测量的94.0%,109.1%,107.7%,80.1%和109.0%,表明三维激光扫描技术获取的0.1m高分辨率DEM可较准确地描述切沟形态特征。0.1,5m2种分辨率DEM提取的切沟长度间无显著差异,但2种分辨率DEM提取切沟宽度、深度、表面积和体积间差异显著。5m分辨率DEM提取的切沟宽度、表面积和体积分别较实际值分别偏大28.6%,25.6%和19.7%;而其提取的切沟深度较实际值偏小37.0%。据此,通过模型筛选,分别建立了0.1m高分辨率DEM与5m分辨率DEM提取的切沟宽度、表面积和体积转换模型。模型验证结果表明,本研究所构建的切沟宽度、表面积和体积转换模型的决定系数均大于0.6,模型有效性系数均大于0.5,说明3个转换模型均具有较好的预报精度,为研究黄土丘陵区沟蚀特征提供了重要方法和手段。     

Phytotoxicity of Biosolids Compost at Different Degrees of Maturity Compared to Biosolids and Animal Manures

Biosolids compost is a good organic amendment but immature compost can exhibit phytotoxic behavior which can be attributed to different toxic substances. Our objective was to determine the phytotoxicity of: i) Biosolids; ii) Mix of biosolids and wood sawdust sampled a day after composting started; iii) The same material sampled at the end of the thermophilic stage; iv) cured compost; v) cow manure and vi) horse manure A germination bioassay was carried out using Lolium perenne (ryegrass) seeds: germination and root growth percentage were determined as well as electrical conductivity, pH, phenol content and volatile organic acids. In three treatments, Ni, Pb, Zn, Cu and Cd were also determined. Ammonia volatilization was determined during biosolids composting. The germination percentage varied from 67% to 95% but the inhibition of root growth appears to be a more sensitive phytotoxicity indicator (18% to 74%. Phytotoxic effects on germinating ryegrass were mainly related to extract pH and electrical conductivity. Potentially toxic elements, volatile organic acids, phenolic compounds and ammonia were not related to germination.     

不同微生物促腐剂在鸡粪好氧堆肥中的应用研究

为了研究不同微生物促腐剂在好氧堆肥上的应用效果,以鸡粪和玉米秸秆为原料,添加3种不同的微生物促腐剂,在好氧条件下进行了高温堆肥试验。在堆肥的不同阶段测定物料的有机质、全氮、全磷、全钾、种子发芽指数及温度,研究3种促腐剂应用过程中以上指标的差异以及变化趋势。结果表明,添加微生物促腐剂可以加速鸡粪腐熟,添加秸秆调节物料的碳氮比(25/1)可以更好地促进菌剂发挥作用,添加微生物促腐剂M2的处理较对照提前8d达到高温期,养分保存效果优于菌剂M1和M3,全氮、全磷、全钾的最高保存率分别为36.36%,8.26%,23.53%。     

不同微生物菌剂对鸡粪高温堆腐的影响

以鸡粪和玉米秸秆为原料,采用好氧堆肥的方式,研究添加三种不同微生物菌剂对鸡粪高温腐熟效果的影响,探索有益微生物菌剂在畜禽废弃物高温堆肥中的作用。分析了堆肥不同时期各处理的堆温、pH值、种子发芽指数、水溶性铵态氮、水溶性有机氮、全氮、有机碳的变化。结果表明,在添加玉米秸秆调节物料碳氮比(25/1)的情况下,添加本研究中所采用的微生物菌剂可以迅速降低物料对种子发芽指数的影响,使发芽指数在21 d内达到80%以上,较对照提高45.52%;对水溶性铵态氮的转化和水溶性有机氮的形成都有明显的促进作用,腐熟堆肥的氮素保持提高25.46%;明显提高堆肥初期发酵温度,使堆体在第2 d达到高温阶段,并持续7 d以上,最高温度比对照高4.8℃,满足堆肥无害化卫生要求,大大缩短堆腐周期。综合多项指标分析,接种菌剂M2对促进有机碳的分解、有机氮的形成和提高腐熟效率更为有利。     

Cumulative Effect of Leaf Compost on Yield And Size Distribution in Onions

For three years, a one inch layer of leaf compost was applied to plots on a sandy terrace soil in Windsor, Connecticut and fertilized with 1300 lb 10-10-10/A (N-P₂O₅-K₂O). Yields of four cultivars of onions (Allium cepa L.) (3 Spanish, 1 storage) from these plots were compared to yields from unamended control plots fertilized at the same rate. Year to year variability in yields was significantly lower in compost-amended plots. Yields from the unamended control plots (52% variation) fluctuated more than the compost-amended plots (3% variation) in response to variable rainfall from year to year. After three years of compost additions, yields from the compost-amended plots of the three Spanish onion cultivars were significantly greater than yields of these cultivars grown in unamended plots. The greater yields were due to both increased bulb weight and greater percent harvested. In two of three years, the compost-amended plots produced a greater percentage of colossal and jumbo sized onions in all cultivars. Repeated compost additions also reduced the incidence of soft rot disease, especially in susceptible cultivars in years with higher than average precipitation.