Recycling of Remediated Soil for Effective Composting Of Diesel-Contaminated Soil

Soil contaminated with diesel oil was remediated by the addition of remediated soil. Several mix ratios of contaminated soil to remediated soil were tested. Judging from TPH degradation rate and biochemical parameters, the optimum mix ratio (wet weight basis) was 1:1. In this mix ratio, the first order degradation rate constant of diesel oil based on TPH was 0.099/day. Degradation rate of TPH and total amount of CO₂ evolved in this condition were two times larger than those of contaminated soil without adding remediated soil. The addition of remediated soil was a very effective treatment option to facilitate the degradation rate of diesel oil in contaminated soil.     

猪粪堆肥快速发酵菌剂及工艺控制参数初步研究

采用L（934）正交设计在模拟发酵池中研究了辅料配比（秸秆添加量梯度为5%、7.5%、10%）、物料含水量（梯度为40%、50%、60%）、通风量（通风时长为10、20、30min）以及外源菌剂（空白、BN1菌剂、EM菌剂）等因素对猪粪堆肥效果的影响。其中BN1为课题组自制菌剂,在测定了菌种纤维素酶活性的基础上,作为外源菌剂接种猪粪堆肥。通过监测堆肥过程中各处理的温度变化,测定堆肥样品总养分含量、堆肥结束后的C/N,并进行感官分析等对堆肥效果进行加权评分。结果表明,猪粪堆肥最佳环境控制参数为秸秆添加量为5%,通风量为每立方米物料102m^3·d^-1,物料含水量60%,自制菌剂BN1能促进猪粪堆肥快速发酵。     

Evolution of Biochemical Parameters During Composting of Urban Wastes

An experiment was performed for evaluating the most suitable biochemical parameters to measure dynamics of substrate transformation during composting of the organic fraction derived from preselected urban wastes and wood bark mixture. Changes of chemical (organic C, hydrosoluble sugars, total and mineral N, humified fraction, volatile acids and phenolic compounds) and biochemical (microbial respiration, biomass C, qCO₂, dehydrogenase, catalase, urease activities, FDA, and BIF) parameters were monitored for 120 days. Limited changes in organic C, total nitrogen, and humification characteristics were observed during composting. Dehydrogenase and catalase activities, BIF and FDA showed small changes during composting. Urease activity and, with some limitations regarding the early stages of composting, microbial respiration and qCO₂, were found to be the most suitable parameters to measure dynamics of substrate transformation during composting of preselected urban wastes.     

Cocomposting of Night Soil and Green Wastes

The feasibility of cocomposting night soil and green wastes (leaves, reed, and grass) and the optimum proportion required to obtain high quality compost for application in Beijing's Olympic Forest Park is investigated. Subsequently, an evaluation of the feasibility of zero discharge of night soil and green wastes was performed. Composting is conducted in three identical 100 L lab vessels. The night soil is mixed with green wastes at three different ratios (4:1, 3:1, and 2:1, night soil:leaves, w:w; 4:1, 3:1, and 2:1, night soil:reed, w:w; 0, 1:3, and 1:1, night soil:grass, w:w;). The mixtures were processed by aerobic composting. Cocomposting was realized at the night soil and leaf mixture ratios of 4:1 and 3:1, with the latter as the best ratio. For the night soil and grass mixture ratios of 0, 1:3, and 1:1, 1:3 is the best ratio while for the night soil and reed mixture ratios of 4:1 and 3:1, the best ratio is 4:1. Based on the annual amount of green wastes (approximately 360 tons of reeds, 1,250 tons of leaves, and 690 tons of grass) and night soil (approximately 300 tons) produced in Beijing's Olympic Forest Park, zero discharge for night soil can be realized through cocomposting. However, this is not the case for green wastes, especially leaves and reeds.     

Evaluation of Parameters During Composting of Two Contrasting Raw Materials

The aims of this work were: i) to evaluate, during a composting process, some parameters in two contrasting raw materials: one a ligneous material (C1) and the other (C2) a mixture of horse and poultry manure with a low straw percentage and ii) to compare results from microbiological and chemical analyses of both composting material during the process. Total carbon, total nitrogen, C: N ratio, ash, organic matter, organic matter destroyed, CEC, soluble organic carbon, soluble ammonium and nitrate, ammonium: nitrate ratio and respiration rate were evaluated during 18 weeks. C1 material showed a lower rate of organic matter mineralization probably due to the high proportion of ligneous material. This material reached a greater CEC during the experiment. Increase in CEC during composting is due to conversion of the remaining organic material into humic substances. These results would imply that C1 presented a greater humification level and consequently, a better quality. On the other hand, the greater decrease in soluble organic carbon and NH₄⁺-N values in C2 is in accordance with greater organic matter mineralization. A high decrease in soluble fractions, especially the more degradable ones (water soluble components) indicates a high mineralization of the organic matter during composting and a lower humification level. According to the data obtained in our experiment, some parameters such as CEC, soluble organic carbon and soluble NH₄⁺-N seem to achieve the stability level for both studied materials, while those parameters or indices such as C: N ratio, NH₄⁺-N: NO₃^?-N ratio indicated stability/maturity only in C2 material during the experimental time.     

牛粪与秸秆协同好氧堆肥过程参数变化规律研究

利用玉米秸秆屑、稻草秸秆屑和牛粪为原料进行序批式好氧堆肥,对堆肥处理的过程参数的变化规律进行了研究。结果表明：2个处理的物料温度在50~54℃维持7 d以上,最终反应产物的无害化程度较高;最终剩余产物的氮、磷、钾相对含量都有所升高,达到了农用控制标准;处理过程中氮素均呈增加趋势;由于在好氧反应阶段存在不同程度的氮损失,因此在反应的后期阶段要注意采取保氮措施。     

Rice Straw Composting and Its Effect on Soil Properties

In Egypt, recycling rice straw and organic wastes is of great concern as well as improvement of soil properties. Rice straw compost could improve both organic waste recycling and soil quality. The aim of this study was to evaluate the effect of the rice straw compost, with or without water treatment residuals (WTR), on soil chemical properties and dry weight of canola. The results showed that the addition of rice straw compost and WTR decreased soil salinity and increased Ca⁺², K⁺ and organic matter. The addition of compost and WTR (2:1 wet weight ratio) at level of 10 g dry weight kg^?1 dry soil gave the best reduction in soil salinity compared to compost or WTR only or for level 10 g dry weight kg^?1 dry soil. The results also showed that the available P decreased with the application of WTR while it increased with the application of compost. The study demonstrated that the dry weight and relative increase (R.I %) of dry weight of canola plants increased with the application of WTR and compost to soil. Combinations of WTR and compost to soils had a greater effect on increasing yield and improved the efficiency of WTR on soil properties.     

松嫩平原土壤孔隙指标与其他土壤指标的相关关系

为了研究东北地区黑土区土壤物理性质变化对土壤功能维持的影响,选取松嫩平原的土壤样品作为试验材料,测定了土壤物理指标中3个孔隙相关指标包括土壤比表面积、容重和孔隙度,10个土壤理化及肥力相关指标包括土壤pH值、电导率(EC)、土壤含水量、土壤有机碳(SOC)、全氮(TN)、碱解氮(AN)、全钾(TK)、速效钾(AK)、全磷(TP)、速效磷(AP)。结果显示:3个指标与其他指标显著相关个数及相关系数R2显示,土壤容重与土壤肥力及理化性质变化相关性最高。不同物理指标对于表征土壤肥力的功能存在差异性,简单线性回归与逐步回归均发现类似的规律:土壤的比表面积与土壤含水量的相关性最强(R2=0.24,slope=0.085),表明土壤比表面积越大,土壤持水能力越强;土壤容重与土壤SOC含量相关程度最强(R2=0.21,slope=-24.92),而土壤的孔隙度与TN含量的相关程度最高(R2=0.08,slope=0.02)。3个指标与养分的不同形式的相关性分析结果显示:它们多与全量养分(TN、TK、TP)相关性较高(R2=0.058),而与养分速效量(AN、AK和AP)相关性较弱(R2=0.026)。     

玉米测土配方施肥技术参数研究

在中等偏上土壤肥力棕壤上开展玉米氮磷钾5处理田间试验。试验结果表明,玉米100kg产量吸氮量为1.81kg～2.53kg,不同施肥配比养分吸收量不同,施肥配比越全面,吸氮量越多;100kg吸磷量(P2O5)1.1kg左右;100kg吸钾量(K2O)1.5kg左右。尿素中氮素利用率50%;普通过磷酸钙中磷(P2O5)利用率为18.8%,氯化钾中钾素利用率为36.5%,尿素和过磷酸钙的利用率较正常,氯化钾利用率偏低,说明氯化钾施用量偏高。土壤氮的校正系数为46.9%,土壤中磷的校正系数为66.1%,钾的校正系数为51.4%。     

旋转锥盘式水稻抛秧机工作参数优化设计

通过对水稻抛秧机秧苗在抛秧盘上的运动分析和受力分析,建立了秧苗在抛秧盘上的运动方程,分析秧苗抛出后的运动规律,通过优化方法计算出一组最佳工作参数,为水稻抛秧机设计提供了理论基础。     

Soil Solarization: Effects on Soil Microbiological Parameters

Soil solarization, obtained by covering soil with plastic films, is a useful practice able to reduce soil pathogen populations. Light plastic films (LPFs) are nowadays widely used especially in open and greenhouse vegetable crop cultivations in Southern Italy, as they are able to raise soil temperature more than 20°C above air temperature. The solarization treatment with LPFs is characterized by a low cost and low environmental impact.

The wide use of these technique causes a concern about the side effect of solarization on soil microbial populations, which are affected the same as plant pathogens by soil heating. As scientific literature pays scant attention to the effect of soil heating on soil microbial parameters, this paper studied the effects of solarization on soil microbial biomass, soil respiration, and soil enzymatic activity in the presence of organic amendments and the soil fumigant dazomet.

Solarization appears to be an effective practice able to control nematodes, even though it may cause serious stress on the soil microbial biomass. In addition, it was demonstrated that the organic amendments exert a protective role keeping soil microbial biomass and enzymatic activities protected from the detrimental effect of heating.     

Composting and Evaluating a Pulp and Paper Sludge for Use as a Soil Amendment/Mulch

Composting could be used in the pulp and paper industry to treat primary sludges as an alternative to landfilling. The objective of this project was to compost and evaluate a pulp and paper sludge for use as a soil amendment/mulch. Primary sludge, tailings, wood ash (0, 5 or 10 percent by volume), and paunch (cattle stomach contents and tissue) from a slaughterhouse were composted in a 91 m windrow that was turned one to two times per week. The pile moisture content and temperature were controlled at 50 percent and 57–63°C during 14 weeks of composting. The compost was then cured for 4 weeks for a total treatment time of 18 weeks. Sludge dry mass decreased by approximately 50 percent, pH increased slightly to 8.2 to 8.5, and carbon-nitrogen ratio decreased from 270:1 to 14–67:1 after composting and curing. Electrical conductivity of all final composts was over 4 dS/m. Shoot biomass of tomato plants grown in a compost-amended medium (50 percent compost, 25 percent sand, 25 percent perlite by volume) improved with composting time but was still only 35–65 percent that of plants grown in a peat moss-amended medium (control). Shoot weight and height of poplar plants grown in soil amended with aged compost were unaffected by compost application rate (incorporated or as a mulch) at less than or equal to 180 Mg/ha. In summary, this study demonstrated that a pulp and paper sludge and wood ash mixture yielded a compost that could be used as a low quality mulch or soil amendment for poplar.     

Comparative Study of Parameters to Evaluate And Monitor the Rate of a Composting Process

Physicochemical, and biological parameters of a composting system were compared to each other with respect to their potential use for the monitoring and evaluation of the rate of field-scale processes. The drying tendency was assumed to be the “exemplar parameter” against which the various process parameters were evaluated for their ability to reveal the process evolution. The organic matter content decrease, moisture content decrease, temperature induced-aeration demand, and respiratory activity were utilized to express the composting rate. The study of these expressions indicated significant correlation of the moisture content removal with the volatile solids decrease, and the respiratory activity. A mathematical model used to describe the profile of these rate indicators during processing. The data analyzed have been derived from a composting process involving a solid substrate (olive-mill solid residues) of which the moisture content was, systematically, corrected by applying olive-mill wastewater.     

Chemical Evaluation of Sewage Sludge Composting as a Mature Indicator for Composting Process

Several chemical parameters were studied during a 100 daysperiod in order to identify parameters that can be used asindicators of compost maturity. One treatment was a mixture ofsewage sludge and sawdust (TS); another was a mixture of sewagesludge, pig manure and sawdust (TS-PM). The pH of water extractsincreased during the thermophilic phase and then decreased in twotreatments. While the electrical conductivity (EC) decreasedthroughout the composting time. The 4.99% in the change ofvolatile matter of TS-PM was higher than 1.73% in that of TS,at the same time, the change of organic carbon were 5.04% inTS-PM more than 3.82% of TS. Total nitrogen content in TS andTS-PM had a markedly increase tendence during composting, andthe change in TS-PM was very more obvious than in TS, soreduction of C/N ratio in TS-PM was higher than in TS, C/Nratio of TS-PM and TS was 14.39 and 18.57 in mature production,respectively. Carbon content in HA plus FA and HA in twocomposts decreased from 0 to 100 day, but carbon content of FAdecreased, so HA-C/FA-C ratio, HR, HI has a markedly increase inTS and TS-PM, and the parameters in TS-PM were higher than inTS. The points expressing maturity degree in TS-PM was more inTS. The nitrogen content of HA plus and HA showed a increasedtendence in TS and TS-PM, the change of nitrogen of thesefractions in TS-PM was higher than in TS, so C/N ratio of allfractions including HA plus FA, HA and FA, indicated a reductiontendence, and the refuction in FA was larger than in HA. E4/E6ratio of HA plus FA and HA decreased during composting, and one FA was increase. E4/E6 ratio of HA plus FA and HA in TS-PM wasvery smaller than in TS, HA in TS-PM was a larger molecular sizethan HA in TS. The changes of organic matter compositions incomposting: the crude fat and carbohydrates had a markedlyreduction and cellulose plus hemicellulose had a slight decrease;crude protein and lignin content in TS and TS-PM had an increasetendence.     

Changes in Properties of Composting Rice Husk and Their Effects on Soil and Cocoa Growth

The worldwide production of rice husk, a by‐product and agrowaste that causes serious environmental problems, may reach 116 million t y^?1. The objectives of this study were (i) to determine the physicochemical changes of rice husk and its structural chemistry during composting using ¹³carbon nuclear magnetic resonance (¹³C NMR) and (ii) to determine the effect of the composted rice husk (CRH) on the properties of Oxisol and cocoa (Theobroma cacao L.) growth under glasshouse conditions. Results showed an active composting phase occurred at the first 53 days as revealed by high carbon dioxide (CO₂)‐C (40–71 µg g^?1 h^?1) production, followed by a matured composting phase occurring at 54–116 days as revealed by decreasing in CO₂‐C production (10 µg g^?1 h^?1). The active composting was accompanied by increases in electrical conductivity (EC), pH, ammonium (NH₄ ⁺), and nitrate (NO₃), whereas during the matured composting phase, the EC and cation exchange capacity increased but pH, NH₄ ⁺, and NO₃ ^?1 decreased. The ash of the produced compost contains mainly calcium (Ca), potassium (K), sulfur (S), magnesium (Mg), and phosphorus (P) as essential nutrients. The CP/MAS ¹³C NMR spectra before and after various composting times indicated the dominance of sharp and well‐resolved signal peaks at O‐alkyl C and di‐O‐alkyl C regions (67–73%), which are characteristic of cellulose. The percentage of N‐alky/methoxyl was 23–26% whereas phenolic, carboxyl, and alkyl C types were less than 3% each. The application of the CRH to an Oxisol significantly increased soil pH and Ca, Mg, K, sodium (Na), and silicon (Si) ions of in situ soil solution but decreased the amounts of toxic ions [aluminum (Al), manganese (Mn), and iron (Fe)]. The CRH was found to increase cocoa growth up to 37%.     

盐碱土壤Philip入渗模型参数的神经网络预报模型

以改良盐碱土壤、提供入渗参数为研究目的,在山西省北部的4种盐碱荒地进行了系列入渗试验和基本理化参数测定试验。基于误差反向传播算法(Back Propagation算法),建立了盐碱地土壤基本理化参数与Philip入渗模型参数之间的神经网络预报模型。预测所得Philip入渗模型参数的平均相对误差如下:稳渗率A为4.30%、吸渗率S为0.31%,预测值与实测值吻合程度高。研究结果表明,基于盐碱地土壤条件,选择土壤体积含水率、容重、质地、有机质含量、全盐量以及p H作为预报模型输入变量,Philip入渗模型参数为输出变量的BP神经网络的预报模型是可行的。     

菜地土壤评价中参评因素的选定与分级指标的划分

菜地选片规划应通过土壤详查和评价工作,选出最适地区,才能经济有效、持续发展。土壤评价中参评因素的选定与分级指标的划分是工作的核心。应选取对蔬菜的生长发育和生产力具有重大影响的、稳定性较高的限制因素,并以土壤属性为主,结合环境条件,因地制宜选定。参评因素的分级应尽量采用定量指标,为分等定级提出定量依据,其主要级差应尽量利用有生物学意义的临界指标。在目前全国无统一规定下,试图面向全国选定参评因素及划分为五等六级的分级指标。     

Land-Use Effect on Selected Soil Quality Parameters

Land use is a key factor that affects soil quality. The purpose of the present study was to investigate changes of selected soil chemical properties related to soil function under different land uses. Five experimental sites arranged in a complete randomized blocks located within the Kalloni watershed (Lesvos Island, Greece) corresponding to different land uses (Pinus brutia forest, brushwood pasture, rain-fed olive grove, wheat, and maize) were compared for soil pH, electrical conductivity (EC), total nitrogen (N), nitrate N (NO₃-N), Olsen phosphorus (P), and organic matter. Soil nitrate and P concentration were in the order corn > wheat > olive > pasture > forest. Soil EC and NO₃-N showed significant within-year variability only in the corn and wheat systems. Corn and wheat had the lowest soil organic-matter content followed the order forest > pasture > olive grove = wheat = corn. However, total N did not significantly differ among land uses.     

Evaluation of Organic Wastes for Composting

Management of organic wastes is essential to reduce environmental pollution and increase resources of plane nutrients for crop production. This study was undertaken to evaluate major organic wastes produced in northwestern Pakistan for characteristics that are useful for composting. Organic wastes such as manures, municipal wastes (MW), crop residues, fruit/vegetable wastes, and yard wastes contained large reserves of nutrients. Manures had high nitrogen (N) and crop residues had low N. Crop residues were relatively dry (7–12% moisture); MW, poultry manure, sheep manure, leaves, and city garbage were moderately moist (27–47% moisture), whereas cattle manure (CM), fruit and vegetable wastes, and grass clippings were wet (62–89% moisture). The compost developed from mixing MW with CM matured early and had low C/N ratio compared with either source alone. These results suggested that MW could be converted into compost when mixed with CM. The inoculation of wastes with effective microbes (EM) was ineffective in expediting the process of composting.