Model calculations of water dynamics in lysimeters filled with granular industrial wastes

A three‐year long lysimeter experiment with a fine‐grained aluminum (Al) recycling by‐product and a mixture of this by‐product and a coal combustion waste was conducted. The wastes were proposed as possible soil substitutes in an engineered surface barrier covering a potash mining residue mount. To evaluate the suitability of the wastes as surface barrier material, their hydrological behavior under field conditions must be known. Lysimeter experiments provide one means to study the hydrological behavior of soils or soil‐like materials. However, it is difficult to estimate the long‐term hydrological behavior from short‐term lysimeter studies. The present study was conducted therefore to derive from short‐term lysimeter observations the long‐term hydrological behavior of the two waste materials. The lysimeter data were used to calibrate the one‐dimensional soil water flow model HYDRUS‐1D. With the calibrated model, hydrological simulations for the site of the residue mount were carried out for a period of 31 yr. Calculated long‐term annual seepage from the lysimeters was 237 mm for the pure Al waste and 186 mm for the mixture, or 39% and 24% of the average annual precipitation (764 mm). The average discharge of the bare mount is 482 mm or 63%. We conclude that a soil cover could considerably reduce the discharge and that the mixture is better suited as surface barrier than the pure Al waste.     

Barley growth in coal liquid and diesel liquid fuels from coal and oil: A comparison of potential toxic effects on Barley

The production of new liquid fuels from coal creates the potential for environmental releases of new products and waste materials via spills or leaching of material from waste storage areas. The chemical composition of these products and waste materials suggests possible toxic effects upon exposed plants and animals. In this study, barley was grown in field lysimeters containing three concentrations (0.07, 0.74, 7.421 m^?2 equivalent to 80, 800, and 8000 gal/acre, respectively) of a sample product blend of Solvent Refined Coal (SRC) heavy and middle distillates. Three methods of soil amendment simulated possible spill clean-up alternatives: adding the coal liquid as a surface layer, as a subsurface layer covered by uncontaminated soil, or intermixed with the top 1 dm of soil. To permit comparison of the coal liquid with familiar commercial material, the study protocol was followed simultaneously in lysimeters amended with # 2 diesel fuel. Statistically significant reductions in grain yield were observed for both the SRC and diesel materials for all methods of soil amendment at concentrations equivalent to 0.74 and 7.421 m^?2, and for the SRC material only when mixed with soil at a concentration equivalent to 0.071 m^?2. Where differences between fuel types were observed, the coal liquid was consistently more toxic.     

Nitrogen mineralization from mature bio‐waste compost in vineyard soils II. Test of N‐mineralization parameters in a long‐term in situ incubation experiment

A field incubation experiment was carried out to test the applicability of N‐mineralization parameters for mature bio‐waste compost for use in a simulation model. The parameters were previously obtained from a laboratory experiment. Micro‐lysimeters were used for incubation, containing four different vineyard soils that were treated with three different compost‐application rates (0, 30, and 50 Mg compost ha^–1). Between 2.0% and 45.2% of total bio‐waste compost N was mineralized and leached from the micro‐lysimeters during the two‐year investigation period. The application of a simulation model for soil N dynamics revealed two major drawbacks of the model: (1) in most of the soils, extraordinary high mineralization rates were observed within a few weeks after compost amendment, which could not be explained by the model, and (2) the average compost‐N‐mineralization rates were estimated as being close to the observed rates (–6%), but distinct deviations in some cases (–46% to +29%) led to considerable miscalculations in long‐term simulations. Excluding the effect of these two processes from the data set, the remaining variance could be well explained by the model for all soils treated with compost (modeling efficiency ≥0.98). Based on the average performance, the mineralization parameters for mature bio‐waste compost are considered to be applicable for use in any simulation model based on the double‐exponential approach for calculating fertilizer recommendations, whereas the functions calculating the impact of environmental factors on N mineralization in the model need to be revised. The initial mineralization flush observed in most of the compost treatments was attributed to a priming effect. The experiment showed that such a priming effect can cause exceptionally high rates of N mineralization from mature bio‐waste compost in a viticultural environment, which exceed the potential mineralization rates known for bio‐waste compost applied to arable soils in Germany.     

Water and Bromide Recovery in Wick and Pan Lysimeters under Conventional and Zero Tillage

Abstract

Quantifying in situ solute transport through soils and the landscape has been widely acknowledged as important and yet challenging. The objective of this study was to evaluate water and bromide movement in no‐tilled (NT) and conventionally tilled (CT) corn using two different types of in situ lysimeters—pan and capillary wick—for single rainfall events. Four zero‐tension pan and four capillary‐wick lysimeters were installed 1.2 m deep on opposite sides of four soil pits. Two were under NT corn, and two were under CT corn. Bromide (Br) was either surface applied or applied with an initial 25 to 27 mm of irrigation (33 to 34 g Br m²). A total of 120 to 147 mm of irrigation was applied continuously at 8.8 mm h^?1. Leachate was collected on 15 min intervals for 24 h and on greater intervals for up to 350 h. Lysimeter discharge and Br concentration were determined for each interval. After drainage began and until rainfall was discontinued, the water drainage rate was, on average, greater in NT (7.2 mm h^?1) than in CT (5.6 mm h^?1) based on results from the pan lysimeters. By contrast, the water drainage rate for the wick lysimeters was, on average, greater in CT (7.3 mm h^?1) than in NT (3.0 mm h^?1). The wick lysimeter appears to have behaved as a sink under the CT conditions, likely representing water flow in smaller channels. Under NT conditions, greater discharge observed with the pan lysimeter implicates the response from larger channels as the conduit for water flow. Flow‐weighted mean Br concentration was less when Br was applied on the soil surface (17.9 mg L^?1) than when Br was applied with the irrigation water (50.6 mg L^?1). Implications from preferential flow studies are often determined based on a single method of evaluation for solute transport, which are likely subject to the limitation of the method used. This study illustrates that contrary to the conventional understanding about preferential flow in NT, water flow and Br transport to the 1.2-m depth was as great as or greater with CT than with NT based on the results from the wick lysimeters for single rainfall events.     

A comparison of water flux measurements: passive wick‐samplers versus drainage lysimeters

Quantification of soil water flow is a prerequisite to accurate prediction of solute transfer within the unsaturated zone. The monitoring of these fluxes is challenging because the results are required to answer both scientific and practical questions regarding protection of groundwater, sustainable management of agricultural, forestry, mining or set‐aside industrial areas, reducing leachate loss from landfills or explaining the fate of environmentally harmful substances. Both indirect and direct methods exist for estimating water‐flux rates and have been used with varying success. In Europe, the use of direct lysimetry methods for measuring water and solute fluxes in soils has increased in recent years. This technique ensures reliable drainage data, but requires relatively large investment and maintenance expenses. Other research groups, especially in the USA, have developed alternative techniques. In this paper we compare the functioning of a passive‐wick sampler, especially the deep‐drainage meter type (DDM), with two different types of drainage lysimeters (weighing and non‐weighing) under field conditions in Germany for the measurement period from May 2004 until April 2009. The study showed that under sandy soil conditions no significant differences occurred between the measurements from DDM and both drainage lysimeter types. Only in periods with increased precipitation was there a tendency of drainage over‐estimation by the DDM in comparison with the lysimeters tested. For longer periods, no significant differences in the amount of drainage or the pattern of drainage formation were found between weighing and non‐weighing gravitation lysimeters. The practical use of DDMs is restricted because the groundwater level must be >2 m from the soil surface. Suggestions are made for the technical improvement of the DDM as well as the testing of the device with more cohesive soils.     

Comparison of type and depth of lysimeter for measuring the leaching losses of nitrogen under urine patches

Abstract. A study of the leaching losses of nitrate under urine patches in irrigated and non-irrigated dairy pastures in the South East of South Australia was undertaken with repacked and monolith lysimeters 1 m deep, and with monolith lysimeters 150, 300 and 450 mm deep. The aim was to quantify differences in measurements of drainage and nitrogen fluxes for these different lysimeters. Drainage of water and N flux were found to vary significantly between types and depths of lysimeters. Drainage volumes in repacked lysimeters were 78% and 33% more than in monolith lysimeters in irrigated and non-irrigated paddocks, and N fluxes were 5 and 3 times higher in repacked lysimeters respectively. The results indicate that lysimeter estimates of recharge rates and N fluxes to water tables are best determined by leaching studies which are longer term, and use deep monolith lysimeters. Shorter term studies and the use of shallow or repacked lysimeters have potential to distort conclusions.     

Unbalanced nutrient ratios in pelleted compound recycling fertilizers

The aim of this study was to contribute to the development of pelleted compound recycling fertilizers with favourable handling and spreading characteristics and balanced nutrient ratios by combining nitrogen (N)‐ and phosphorus (P)‐rich waste resources (meat bone meal, fish sludge or food waste) with potassium (K)‐rich bottom wood ash. Pelleted compound recycling fertilizers with good durability and low dusting tendency were produced by roll‐pelleting preheated waste resources at a suitable moisture content. However, the nutrient ratios in the final products were insufficiently balanced, with too low N concentrations relative to P and K to meet crop demands. In a bioassay using barley (Hordeum vulgare ) and a nutrient‐deficient sand/peat mixture, the relative agronomic effectiveness (RAE ) of pelleted compound recycling fertilizers and reference recycling fertilizers was 22–42% of that of mineral compound fertilizer. Growth limitation was due to reduced N availability (mineral fertilizer equivalent ‐ MFE = 35–57%) or reduced P availability (MFE  = 20–115%), with the greatest P fertilizer value obtained for digestate based on dairy manure and fish sludge. Availability of K in bottom wood ash was masked by the experimental soil.     

北方典型农村生活垃圾分类模式初探——以曲周县王庄村为例

以华北平原上的曲周县王庄村为研究对象,在对村民进行环境意识调查的基础上详细分析了生活垃圾组成及农业活动旺季垃圾的变化趋势,并对生活垃圾分类进行了典型示范。结果表明,村民对垃圾污染问题较为关注,并希望能回收利用,但主动改善性不强;王庄村生活垃圾成分较为简单,主要可分为有机垃圾、无机垃圾、塑料垃圾及有害垃圾4大类,产生量为有机垃圾〉无机垃圾〉有害垃圾〉塑料垃圾,其中有机垃圾占主要部分,达到56.76%;农户种植生产活动对有机垃圾和有害垃圾的产生有显著影响,无机垃圾产生量则主要与农户的燃料结构变化有关。通过对垃圾分类试验的效果进行分析得出,北方以种植业为主的农村地区适宜采取以村为单位的垃圾分类收集方法,并实施村委会-保洁员-农户三方的监督机制和适当奖惩措施,垃圾处理方式开始宜采取卫生填埋兼以废品回收的无害化模式,并逐渐过渡到分类利用的资源化模式。     

Ferrous metals — Recovery and reuse

Economics, as well as environmental considerations, are giving a new impetus to resource recovery and recycling. while scrap steel cans have been magnetically separated from municipal solid waste systems for many years, recent sharp increases in the price of steel scrap are making it economical to mine existing landfills for ferrous metal. Rapidly escalating fuel costs coupled with fuel shortages and diminishing readily accessible landfill sites are influencing a growing number of communities to burn solid waste as a fuel. At least 30 such systems — using a variety of techniques — are in operation or the construction or planning stages. Almost every one of these systems calls for the removal of steel cans for economic, environmental or fuel efficiency reasons. A number of these garbage-to-energy systems also involve the salvage of other non-combustible materials. As a result of an on-going research program sponsored by American Iron and Steel Institute an additional market for scrap steel cans may soon join the four traditional markets for this type of scrap. Successful tests have been conducted in iron foundries using scrap cans recovered from municipal solid waste. The more than 2000 foundries located throughout the country put most urban areas within easy shipping distance of these new markets for scrap steel cans. In addition, the four existing markets for reclaimed steel cans: steel mills; copper mining, which uses can scrap as precipitation iron in a process that recovers copper fiom low grade ore; detinning plants which recover both the steel and its tin coating for recycling; and ferroalloy plants all have increased interest in this product. In order to serve the markets effectively and obtain the best prices for their product — scrap steel cans — municipalities must be aware of the different specifications that each market has.     

Analytical Studies on Lead Pollution in Roadside Soil Samples of Raipur and Bhilai,Chhattisgarh State,India

Abstract

Although lead in gasoline represents only 2.2% of total global lead use, this fuel remains by far the single largest source of this heavy metal in urban areas. In developing countries like India approximately 90% of all lead emissions into the atmosphere are due to the use of leaded gasoline. In many countries in Southeast Asia, unleaded gasoline is scarce, and the maximum allowed lead content might reach or exceed 0.8 ppm per liter. Emissions from the metallurgical operations and the waste incineration are also responsible for the rising levels of lead in the environment. Battery recycling, lead‐glazed pottery, and lead pigments industries are other sources of lead in the environment. In the present work, lead pollution in soil samples from Raipur (capital city) and Bhilai, Chhattisgarh State, India, has been investigated. The lead concentration in the surface soil of Raipur and Bhilai was found in the range of 7.2–84.0 and 9.5–79.7 ppm, respectively. The seasonal and temporal variations in the concentration of metal, its distribution pattern, and trend are discussed as well as the mobility, deposition, and sources of lead in the area. The enrichment factor of lead in the urban soil was found to be very high, depending on the nature of sources.     

SOME EFFECTS OF MOUND-BUILDING TERMITES ON SOILS IN UGANDA

Most large mounds in Uganda are built by termites of the genus Macrotermes. Except for those in valley bottoms they are composed of subsoil which is thought to be collected mainly from depths of 0.5 to 1.0 m, although the evidence is inconclusive. Mounds of both M. bellicosus and M. subhyalinus contain less sand than the subsoil when this is sandy, but only M. subhyalinus mounds contain less clay when the subsoil has a high clay content. In general both species tend to produce a stone-free topsoil whose physical properties are closer to a loam than the average subsoil. Mounds of both species in valley bottoms appear to be built from topsoil. The amounts of organic matter, nitrogen, calcium, phosphorus, and potassium in mounds were estimated together with their rates of turnover. In terms of the demands of two typical crop plants the quantities held in mounds and their rate of release to the surrounding topsoil were small. Only calcium was likely to be cycled in significant amounts. It seems that termites only slightly affect the physical and chemical properties of Ugandan soils, even where mounds are comparatively abundant.     

Effect of vegetation restoration on ant nest‐building activities following mobile dune stabilization in the Horqin Sandy land,Northern China

Measurements of the density and characteristics (size and height) of ant mounds were carried out on mobile, semi‐mobile, semi‐fixed and fixed dunes in the Horqin Sandy Land, Northern China. The relationships between the distribution of ant mounds and the plant community (abundance and cover) were investigated, for areas within and across the dune stages. Changes in spatial pattern of ant mounds were also analysed following mobile dune stabilization. The results showed no ant mounds on mobile dunes; the mound density was significantly higher on fixed dunes than on semi‐fixed or semi‐mobile dunes. The mound density depended on plant density and cover across all dune stages, but not within any dune stage. The mound diameter increased but the mound height decreased from semi‐mobile dunes to fixed dunes. However, the mound diameter and height were not related to plant cover and density within any stabilization stage or across all dune stages. The spatial pattern of ant mounds tended to change from more clumped (semi‐mobile and semi‐fixed dunes) to less clumped and approached a random pattern (fixed dunes) along the dune stabilization gradient, which was related to the changing vegetation pattern during succession. Although the quantification of the number of ant species present was not attempted on each dune, the observed differences in ant colour and size suggest at least eight species were present. Fixed dunes were more attractive for different kinds of ant species, but the mound distribution exhibited a more random pattern with more continuous vegetation. Thus, different environmental conditions, especially in terms of the plant communities present at different dune stages, affected the activities and behaviour of the ants (including the distribution of mounds), but did not affect mound size and height. Copyright © 2009 John Wiley & Sons, Ltd.     

出菇次数调控菌糠基碳孔隙结构与载硫电极储锂性能分析

针对食用菌培养基废弃物（菌糠）的资源浪费与环境污染,以及商业碳材料制备复杂等问题,该研究提出选取了不同出菇次数的菌糠作为原材料,通过简单的高温碳化方法,制备了一类低成本、微观结构各异的生物质多孔碳,经KOH高温活化调控产物孔径后,作为碳骨架材料应用于锂硫电池正极中,探究出菇次数对其电化学性能的影响。结果表明,出菇1次菌时,菌糠内营养物质部分分解产生孔隙,且滋生大量菌丝,经过KOH辅助活化碳化后获得具有发达三维孔道的海绵状碳骨架（AMRC-Ⅰ）,其比表面积显著增大（1 591.06 m2/g）,介孔比例提高（88.03 %）,有利于提高电化学活性物质利用率,表现出较高的初始放电比容量（1 111.31 mAh/g）和稳定的循环寿命（100次循环后保持355.99 mAh/g的可逆容量）。该研究表明出菇次数可以调控菌糠基碳骨架的微观结构,进而影响其作为锂硫电池正极基体时的电化学性能,为菌糠废弃物的高价值利用提供了新思路。     

自然村生产生活废弃物循环利用模式及其评价研究

农业农村生产生活废弃物循环利用是实现农村人居环境治理、提高资源利用效率的重要途径,对美丽乡村建设具有重要意义。该文以自然村为研究对象,采用层次分析法和模糊评价法相结合的方法,统筹考虑生产生活废弃物循环利用,构建了自然村生产生活循环技术模式评价指标体系,确定各项指标的权重,建立评价方法。以河北邢台市山区某村为例,针对其生产生活废弃物产生特点,构建生产生活废弃物循环利用体系,该村农业废弃物以果木剪枝、生活垃圾、生活污水、人畜粪尿等为主,通过构建以果木剪枝热解+炭基有机肥还田为纽带的循环利用模式,辅以污水处理利用技术,实现了废弃物能源化和就地肥料化利用。通过对该自然村循环利用模式进行实地评价验证,结果表明该自然村生产生活循环技术模式评分结果为优。该文为中国村镇废弃物循环利用技术模式选择、农村人居环境改善和农业绿色发展提供参考和借鉴。     

Potential movement of methyl bromide through golf course greens

Abstract

Methyl bromide (MeBr) is routinely used for soil sterilization and stored food preservation. There is increasing concern for the continued use of MeBr due to the influence of methane and MeBr on the ozone layer in addition to its high mammalian toxicity. MeBr is commonly used for sterilizing golf course greens during construction and renovation. The high water solubility of MeBr and bromide ion (Br) and the high infiltration rate of most golf course greens allows for potential movement of these analytes into drainage channels and ultimately into surface contained water systems. The objective of this research was to develop a sensitive and accurate method for quantifying MeBr and Br in aqueous soil leachate and to determine the potential for MeBr and Br transport through golf course greens following fumigation. A method for utilizing a purge and trap system coupled to a gas Chromatograph equipped with an electron capture detector (P&T/GC‐ECD) was developed for measuring MeBr. This system along with the LACHAT system for Br analyses in the purged subsample were used to quantify MeBr and its metabolites in aqueous leachate obtained from lysimeters developed to simulate treatment of renovated greens using MeBr fumigation. MeBr was applied to the enclosed lysimeters at rates of 533 and 65 g m^‐2 in two experiments. At 2 days after treatment (DAT), tops of the lysimeters were removed and at 4 DAT simulated rainfall and irrigation events were initiated. The leachate was collected from the bottoms of the lysimeters for a 22 day period and analyzed for MeBr and Br transported through the soil mixture. The sum of transported MeBr and Br from the two experiments was proportional to the treatment rate. Considerably more Br was transported than MeBr. The highest concentration of MeBr and Br in the leachate from both experiments was 11.8 and 57.2 mg L^‐1, respectively. The total MeBr and Br transported through the golf course greens rooting medium, accounted for less than 1% of the analyte applied at both treatment rates.     

土壤深度对土磷素淋失的影响

利用渗漏池设施,研究了冬小麦-夏玉米轮作条件下不同土壤深度对土磷素淋失的影响。种植8季作物结果表明,对深度小于80 cm 的渗漏池,淋出土体的累积渗滤液量和累积全磷量随化学磷肥施用量的增加而减少; 随土层深度的增加,淋出土体的渗滤液和磷量均减少,且二者的减少率都很接近,表明磷素淋失主要受通过土体的土壤水分控制。相对于深度小于80 cm的土层,供试土壤的粘化层有效地减少了土壤渗滤液和磷素淋失。各深度渗漏池渗滤液中的磷以可溶态为主,约占全磷的70%左右,颗粒磷约占30%。合理施肥并加强水分管理是土区减少磷素向土壤深层迁移的有效手段。     

我国南方地区钾肥使用及市场调查研究分析

研究我国南方地区钾肥使用与市场需求情况,为稳定和恢复钾肥市场供需平衡提供决策依据。2011年,选取农用钾肥代表性较强的湖南和广东两省6个地区的200名县、乡经销商和400名农户作为调查基础,经过电话采访和实地走访调研,综合分析了我国南方地区农户钾肥使用的现状与需求变化情况。结果表明,1)氮磷钾复混肥正在成为替代农用钾肥的首要产品;2)当前农用钾肥终端市场价格相对合理,处于农户可以接受区间的上限;3)经销商对单一钾肥的推广意愿正在下降;4)经济作物种植农户和种植承包大户是促进农用钾肥需求恢复的主要目标群体;5)产品品牌是影响农户对农用钾肥的购买因素之一。因此,我国南方地区钾肥使用与市场需求要进一步梳理经营渠道,发挥县、乡级经销商的网络及配送作用,以经济作物种植农户和种植承包大户为重点培养对象,稳定和恢复钾肥市场与需求。     

Simulation of water flow and solute transport in free-drainage lysimeters and field soils with heterogeneous structures

Lysimeters are valuable for studying the fate and transport of chemicals in soil. Large‐scale field lysimeters are used to assess pesticide behaviour and radionuclide transport, and are assumed to represent natural field conditions better than laboratory columns. Field lysimeters are usually characterized by a free‐draining lower boundary. As a result, the hydraulic gradient is disrupted, and leachate cannot be collected until the bottom of the lysimeter becomes saturated. We compared heterogeneously structured, free‐drainage lysimeters and field soils with respect to water flow and solute transport. Numerical simulations were carried out in a two‐dimensional heterogeneous sandy soil under unsaturated water flow conditions with the CHAIN_2D code. Three different soil structures (isotropic, horizontal, and vertical) were generated, and Miller–Miller similitude was used to scale the hydraulic properties of the soil. The results showed that ponding occurs at the bottom of the lysimeter for the three soil structures and that it occurred faster and was more pronounced with the vertical structure (preferential flow effect). Breakthrough curves of a conservative solute (bromide) showed that solutes are moving faster in the field than in the lysimeters. Fewer differences between lysimeters and field soils were found with the horizontal soil structure than with the isotropic and vertical structures.     

The total concentration and fractional composition of the aluminum compounds in soil solutions from peaty-podzolic-gleyic soils developed on binary deposits

The total concentration and fractional composition of aluminum compounds were determined in soil solutions obtained using vacuum lysimeters from the main genetic horizons of peaty-podzolic-gleyic soils developed on binary deposits. The total concentration of aluminum in the brooks draining the area with a predominance of these soils was also estimated. The total aluminum concentration in the soil solutions reached the maximum values (0.079–0.092 mmol/l) in the Eih horizon and generally decreased down the profile. The aluminum in the soil solutions occurred in the form of monomeric inorganic and organic compounds and complexes with high-molecular-weight organic acids. The proportion of inorganic monomeric aluminum compounds in the solutions from the peaty-podzolic-gleyic soils increased compared to that in the podzolic soils; no aluminosilicate compounds were found. Aluminum arrived to the brooks draining the areas with the predominant peaty-podzolic-gleyic soils mainly from the above-moraine horizons, including the Eih, E, and Ecn. It was supposed that the removal of aluminum from these soils exceeded that from the podzolic soils.