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.     

Thermal and Spectroscopic Characterization Of Composts From Municipal Solid Wastes

Six composts from municipal solid wastes (MSW) were sampled after composting times of 3, 7, 15, 45, 60 and 350 days and analyzed by chemical analysis, fluorescence spectroscopy in emission, excitation and synchronous scan modes, Fourier transform infrared spectroscopy and differential scanning calorimetry, without carrying out any organic matter extraction. Thermal and spectroscopic techniques appeared to be powerful tools to investigate the evolution of MSW organic matter during composting, and provided evidence that the chemical transformations occurring in these heterogeneous materials yield products with molecular complexity and stability, similar to humic substances.     

Ryegrass Response to Mineral Fertilization and Organic Amendment with Municipal Solid Waste Compost in Two Tropical Agricultural Soils of Mali

Abstract

A pot experiment was conducted to assess the effect of mineral fertilization and compost on the growth and chemical composition of ryegrass (Lolium perenne L.) grown on two Malian agricultural soils coming from Baguinéda, abbreviated as Bgda, (12°23′ S, 7°45′ W) and Gao (16°18′ N, 0°). Treatments included non‐fertilized control, NPK alone, NPK + C₂₅, NPK + C₅₀, NPK + C₁₀₀, PK + C₅₀, NK + C₅₀, NP + C₅₀, K + C₅₀, P + C₅₀, N + C₅₀, and C₅₀ alone, where NPK represents the non modified Hoagland's solution and C₂₅, C₅₀, and C₁₀₀ represent the different rates (25, 50, and 100 T/ha) of compost. Compost and mineral fertilization significantly increased dry matter production. The application of 50 T/ha of compost alone increased the dry matter yield by 10 and 17.5% while mineral nitrogen–phosphorus–potassium (NPK) increased yield by 69.7 and 65% for Gao and Bgda, respectively. The combination of compost and mineral NPK (NPK + C₂₅ for Gao and NPK + C₅₀ for Bgda) affected the highest dry matter yield. For both soils, N concentrations in plants increased significantly with compost rate. Phosphorus and K concentrations in plants varied according to the soil. The application of compost increased the uptake of iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), and potassium (K from both soils). Increases in soil organic carbon, available P, calcium (Ca), magnesium (Mg), Fe, Mn, Zn, Cu, K, and pH were observed in treatments receiving compost. Therefore, compost appeared to be a good supplier of nutrients for tropical soils.     

Cost Considerations of Municipal Solid Waste Compost: Production versus Market Price

? As more composting facilities come on line across the United States, and a wider spectrum and greater quantity of organic materials are composted, the need to develop a variety of markets for their end products, i.e., compost or mulch, will become ever more critical to the future growth potential for composting and its success. It is often stated that high quality compost will always find a market. However, the economic implications of producing a high quality compost need to be better understood. Publicly and privately operated composting facilities need to compare the costs for building or improving their composting programs to the associated economic returns, i.e., the increased selling price for their product (or, if the product is not sold, the increased avoided cost for what the compost/mulch product is substituted for) and other economic implications.

The scarcity of published information on the costs of producing marketable compost at U.S. municipal solid waste composting (MSW) facilities is largely due to the minimal experience in producing and marketing these composts in this country. In order to improve both facility operation and compost quality, most facilities that have operated for more than one year are making modifications, particularly in the type of feedstock, front-end process, composting process, and final compost processing. A summary of such changes is presented for nine U.S. plants, but little information is available on the costs of these modifications, nor their impact on compost quality. Information is also presented about the European experience with MSW composting, emphasizing the importance of producing better quality compost, and the need to fully account for the added costs associated with producing a higher quality compost.     

Enzyme Activities as Indicators of Municipal Solid Waste Compost Maturity

Composts of municipal solid waste in a commercial scale facility were assayed for enzymatic activities over time. The main enzymes assayed in this study were alkaline phosphatase, acid phosphatase, endo-cellulase, glucosidase, and lipase (C10). The biomass was measured by using lipid phosphate as a measure of the amount of cellular membranes, and metabolism was measured by the amount of 14_C-acetate incorporated into the lipid phosphate pool. All tests followed steady trends which show promise for use as possible stability and maturity indicators. Cellulase activity appears to be a good indicator of stability. The lipase activity appears to be a good indicator of compost maturity. A simple test strip (Api-Zyme from Api Analytab Products, Plainview, New York) was also used and compared to the standard enzyme assay methods. Api-Zyme and standard methods gave comparable results. The use of specific enzymatic activities presents an inexpensive and fast method, which may be combined with others, to predict a composts' stability and possible maturity status based on microbial activity.     

Study of Organic Matter Evolution in Citrus Compost by Isoelectrofocusing Technique

Three composts from citrus-processing industry wastes, sampled at prefixed times during the composting process, were studied with the aim to follow the organic matter evolution by using the isoelectrofocusing (IEF) technique. Results indicated that IEF qualitative analyses allowed evaluation of the organic matter transformation during composting process, showing a decrease of IEF peaks focused at lower values of pH (less stabilized organic matter) and a corresponding increase of peaks focused at higher value of pH (more humified material). The parameter A %, defined as the areas sum of IEF peaks focused at pH>4.7, could be considered particularly effective as a “threshold value” to evaluate the level of organic matter evolution for the considered composts.     

Effects of Municipal Solid Waste Compost on Soil Properties and Vegetables Growth

ABSTRACT

This work investigates the impact of municipal solid waste compost (MSW-compost) application (0, 50, and 100 t/ha) on the growth, and on nutrient and trace elements content in lettuce and tomato plants grown in large, 40-L pots. Our findings showed inhibition of plants’ growth with increasing dose of MSW-compost, compared to plants receiving conventional fertilization. Growth inhibition was associated with a sharp decrease in soil NO₃–N content. On the other hand, a slower decrease in soil NO₃–N content occurred in non-planted pots amended with MSW-compost. These findings provide evidence that N immobilization and/or decreased N mineralization were responsible for inhibited growth by constraining N availability. With regard to the other macro-nutrients, K, P, Mg, Ca, and Fe, their contents in leaves of both crops were maintained at optimum levels. Higher zinc and copper content was measured in leaves of both crops but they did not exceed the optimum range for growth. No accumulation of trace elements was found in the fruits. The content of heavy metals in the tissues of plants grown in MSW-compost amended soil, remained at levels similar to those of the non-amended soil, suggesting that they do not pose a significant risk either for plant growth or public health. The findings of our study suggest that further emphasis should be given on the investigation of the factors regulating N mineralization and availability in order to avoid reductions in crop yield.     

Efficiency of Organic Compost from Agri-Industrial Wastes as Fertilizer for Corn and Wheat

Favorable effects of organic wastes on soil characteristics are capable of permitting a sustainable agriculture. This experiment was conducted to evaluate the effects of organic compost from two agri-industrial wastes on soil fertility and productivity of corn and wheat in Astorga County, northwestern Paraná, Brazil. The organic compost had components from the gelatin industry, which uses bovine chips and shavings by-products from the tannery industry and by-products (filter cake and plant straws) from the sugarcane industry. The experimental design was randomized complete block with eight treatments and four replications. Only the wheat had increased productivity, and there was no response to doses above 25 t ha^?1. Not all levels of organic compost affected the soil electrical conductivity.     

Heavy Metals Analysis of Solid Municipal Wastes in the Western Part of Nigeria

The heavy metal contents of solid municipal wastes produced at various (sites) in Lagos (1), Ibadan (1), Ogbomoso (2), Ilorin (1), Osogbo (1), Ile-Ife (1), Ejigbo (2), Iwo (1) and Oyo (1) were measured. The solid municipal wastes produced in high density towns showed higher levels of iron, zinc, and cadmium (P <0.05). There is no significant difference (P <0.05) between the mean concentrations of other metals in the high and low density towns. The inter-element correlation and significance of some heavy metal levels in Nigerian environment are discussed.     

Elemental Analysis of Municipal Solid Waste Compost II. Refuse Derived Fuel Unders

In utilizing municipal solid waste (MSW) as fuel for energy production, about 10 percent remains as a noncombustible small size fraction byproduct called refuse derived fuel unders (RDFU). We assessed the feasibility of using RDFU to produce compost for land applications, in the context of acceptable limits for metals. Periodic random samples from two batches of RDFU obtained during composting were analyzed for the heavy metals Cd, Cu, Pb, and Zn, and for the plant nutrients N, P, and K. The heavy metal content (mg/kg, dry weight) in all samples ranged from 1.7-12.7 (Cd), 201-3217 (Cu), 267-5002 (Pb), 344-2079 (Zn). The total variability of these elements within a batch of RDFU compost was high, with relative standard deviations (RSD) ranging from 20-107 percent. Estimates of the number of samples needed to obtain a 10 percent uncertainty in the averages ranged from 5-138, depending on the analyte and the compost batch. Leachability tests showed little leaching of metals in the RDFU compost. The high variability in heavy metal content and the excessive Pb concentrations in this RDFU may limit its use for composting.     

Modification of Soil Water Retention and Biological Properties by Municipal Solid Waste Compost

A compost originating from the organic fraction of MSW, separately collected, was added to a loamy soil at different application rates. Modifications of soil physical and biological properties were studied after compost addition. Water retention properties, after compost addition to soil, were monitored. Organic carbon mineralization was followed during a six-month incubation. Enzyme activities were assayed immediately after compost addition, as well as after incubation of soil-compost mixtures. These properties provided information about the modification of overall microbiological activity and specific nutrient cycles in the amended soil. Water retention, carbon mineralization and most enzyme activities after incubation were increased by compost incorporation. The additivity or nonadditivity of compost effects on soil properties was discussed.     

Nutrient Release Dynamics in Soils Amended With Municipal Solid Waste Compost in Laboratory Incubations

Two municipal solid waste composts were added to three agricultural soils developed over different parent material (schist, gabbro and granite) and incubated in two laboratory studies, in order to assess the effect of compost addition in the dynamics of soil Ca, Mg, K and P. Soils and mixtures of soil and compost (2.5% dry weight, roughly equivalent to 60 t ha^?1) were incubated at 25°C for three months in a first experiment, and for five months in a second experiment. The concentrations of available Ca, Mg, K and P were determined throughout both experiments. The soils amended with compost always had higher available Ca, Mg and K concentrations than the soils without amendment. The increases were approximately 800 mg kg^?1 for Ca, 30 mg kg^?1 for Mg, and 150 mg kg^?1 for K. Nevertheless, the concentrations of these elements did not increase with time. The available P concentrations were not increased by the addition of compost, an effect which is attributed both to microbial immobilization and to the P-fixation capacity of the soils. Therefore, the expected release of these elements in parallel to compost mineralization was not observed during the experiments, and the only fertilizing effect of the compost was that of their initial input in available forms.     

The Effects of Municipal Solid Waste Compost And Compost Tea on Mineral Element Uptake And Fruit Quality of Strawberries

Three levels of municipal solid waste compost (MSWC) and two application rates of compost tea made with MSWC were applied to strawberries for two years. The highest level of application of MSWC significantly increased the concentrations of most extractable soil mineral elements except for Ni which was increased in the highest compost tea application rate. Despite large differences in soil mineral element concentrations among treatments, plant and fruit uptake were generally unaffected by treatments. Notably however, compost tea applications increased fruit Na levels perhaps due to increased uptake of Na by leaves compared to roots. Generally, the composts and compost teas produced fruit of equal quality in terms of total antioxidant capacity and vitamin C but all treatments failed to provide sufficient N to strawberry plants and all fruit appeared to have leather rot; consequently, yield was decreased.     

Utilization of Municipal Solid Waste Compost: Research Trials at the Johnson City,Tennessee Facility

? In 1963, the Division of Health and Safety of the Tennessee Valley Authority (TVA) proposed construction and operation of a composting plant at some medium-sized city in the valley, primarily as a means of disposing of solid wastes, but also as a means of converting wastes into a material useful for erosion control, land reclamation and soil improvement. The U.S. Environmental Protection Agency (EPA) and the TVA cooperated in the operation of a composting plant at Johnson City, Tennessee from 1967 to 1971. An outdoor windrow process was used. Sewage sludge was incorporated with the MSW up to 20 percent of the total compost solids.

Johnson City compost was used in numerous demonstrations in eastern Tennessee and western North Carolina, starting in the fall of 1968. Replicated field plot experiments were also carried out at Muscle Shoals, Alabama and eastern Tennessee. This report reviews results of those demonstration studies, as well as analyses of material used for stripmine reclamation and for ash pond stabilization. The results were in papers published by agronomists on the TVA staff in the 1970s. Data over a 19-year period following compost application are reviewed for impact on crop yield, organic matter and nutrient supply.     

Effect of Municipal Solid Waste Compost and Compost Tea as Fertility Amendments on Growth and Tissue Element Concentration in Container-Grown Tomato

Evaluation of fertility sources for certified organic greenhouse vegetable production is necessary for further industry growth. Two experiments tested the effects of municipal solid waste compost (MSWC) and water extract tea made from it on potted greenhouse tomatoes. The first used MSWC alone (two levels) and soil tea drench alone (three application frequencies). The second used MSWC and tea in factorial combination at three levels (0, 1×, and 2×). The greatest yield and leaf tissue potassium (K) were obtained using the greatest level combinations of compost and foliar tea spray, and this was significantly greater than conventional nitrogen-phosphorus-potassium (NPK) fertilizer yield. Tissue magnesium (Mg) was affected by compost because of the antagonism from compost K. Tea increased tissue sodium (Na). No significant differences in heavy-metal tissue concentrations were found between treatments. While MSWC is an effective soil fertility amendment, the benefits of using tea may be increased with more frequent application.     

Compost Changed Soil Organic Matter Molecular Composition: A Py-GC/MS and Py-FIMS Study

Changes in the molecular composition of soil organic matter (SOM) resulting from compost application are not sufficiently known at the molecular scale even though this is a major issue for soil fertility and soil carbon sequestration. Therefore, the present study investigated effects of long-term compost application in comparison to mineral fertilizer on the molecular composition of SOM in a 34-year-old experiment. Soil samples were taken after 19 and 34 years of constant management and analyzed by Curie point Pyrolysis-Gas Chromatography/Mass Spectrometry (Cp Py-GC/MS) and Pyrolysis-Field Ionization Mass Spectrometry (Py-FIMS). In general, compost application increased the organic carbon (C) content. The Cp PyGC/MS revealed larger relative intensities of alkylphenols/lignin monomers at the expense of carbohydrates in the compost treatments. Py-FIMS indicated higher proportions of labile n-fatty acids, lipids and sterols in the compost than in the mineral fertilizer treatment. Permanent cropping of grass between years 19 and 34 revealed similar signal patterns, which is also maintained after conversion of soil from permanent grass to arable use. Thermograms of volatilization indicated enrichments of stable (compounds volatilized in between 370°C and 570°C) phenols/lignin monomers, lipids and alkylaromatics between years 19 and 34 in compost fertilized soils. This was a result of enhanced losses of compounds that are considered easily metabolized by microorganisms (e.g. carbohydrates) after compost addition as derived from Py-GC/MS and Py-FIMS. In summary, long-term application of mature compost was shown to have a positive, long lasting effect on the organic carbon sequestration in agricultural soils.     

Municipal Solid Waste Compost Application Improves the Negative Impact of Saline Soil in Two Forage Species

Inappropriate utilization of biosolids may adversely impact agrosystem productivity. This article addresses the response of H. vulgare and P. monspeliensis to different doses (0, 100, and 150 t ha^?1) of municipal solid waste (MSW) compost in a greenhouse pot experiment. Plant growth, heavy-metal uptake, gas exchange, and photosynthetic pigment concentrations and photosynthesis parameters were considered. Results showed that compost supply significantly increased shoot and root dry weights of both species, and this was positively correlated with nutrient uptake. Chlorophyll and carotenoid contents were positively influenced, especially in H. vulgare at rate of 100 t ha^?1. Furthermore, MSW compost application increased net photosynthetic rate (A), stomatal conductance (Gs), and water-use efficiency (WUE) in both species. Alternatively, MSW compost amendment increased plant heavy-metal contents but levels remained lower than phytotoxic thresholds. This preliminary study suggests that a MSW supply at moderate doses (100 t ha^?1) could be highly beneficial for plant productivity on saline soils.     

Effect of A Waste Stream Component on the Agronomic Properties of Municipal Solid Waste Compost

Managing municipal solid waste (MSW) compost for agricultural use requires an understanding of waste stream components and how they affect the value of the finished product. We evaluated the influence of disposable diaper content in MSW compost because of the recent concern of the environmental impact of this product. To determine the potential effect of disposable diapers on MSW compost, the ‘normal’ concentration of soiled, disposable diapers in a waste stream was raised from 2 percent to 8 percent. Previous observations indicated that the diapers disassociated during in-vessel digestion and most of the components could not be distinguished from the primary compost. The objective of this study was to examine the effect of additional diapers on the agricultural value of mature MSW compost. Loamy sand and silt loam soils were amended with MSW compost at a rate of 20 percent. Comparisons between the two composts and their interactions with soil type were made on the basis of water retention characteristics; germination and emergence of corn, soybean, radish and lettuce; and yield and element uptake by corn and lettuce at two moisture regimes. Differences between the compost amended soils suggested that the primary benefits of additional diapers were increased nutrient availability and soil water retention, and the foremost concerns were excess total soluble salts and boron.     

Characterization of the Soil Organic Matter in Agricultural Mine Spoils and Reclaimed Soils Treated with Organic Amendments

Recycling organic waste in agricultural soils is a valid solution. We performed short‐term experiments to investigate the fate of urban sludge and composts, in mine spoils, cultivated or uncultivated, and reclaimed soils located in Florence and Milan, Italy. The samples, either treated or untreated, were fractionated by density into light (<1.63 Mg m^?3) and heavy (>1.63 Mg m^?3) fractions. The fractions were analyzed for total carbon (C) and nitrogen (N) contents and for δ ¹³C and δ ¹⁵N isotopes, and they were characterized by ¹³C NMR spectroscopy. Treatment increased the heavy fraction. The addition of sludge in the Florence area acts in synergy with the cultivation, increasing the light fraction (LF). In the Milan area, the LF tends to be decomposed and apparently transformed into HF. The addition of amendments or cultivation enhances the decomposition with release of carbon dioxide. For future research, we suggest lengthening the time of the experiments to integrate climatic variations.     

Ameliorative Effect of Municipal Solid Waste Compost on the Biological Quality Of Mediterranean Salt Lake Soil

Different loads of municipal solid waste compost (MSWC) were applied to hyper saline salt lake soil under laboratory conditions to monitor biological soil quality. Microbial biomass-C (MBC), catalase, dehydrogenase, urease, alkaline phosphatase, arylsulfatase, and β-glycosidase activities were analyzed following 14, 30, and 50 days of incubation. In general, MBC and the oxidoreductase and hydrolase enzyme activities were significantly enhanced by addition of MSWC at 20 and 40 t ha^?1 doses, but they decreased at 120 t ha^?1. Overall, the results show that the addition of MSWC to hyper saline soils can improve soil biological quality, in spite of its high salt content, which is an important step in any attempt to use them as biosaline agricultural soils. However, substances such as heavy metals in MSWC could limit the use of compost for this purpose; consequently, analysis of MSWC is recommended prior to its use.