ISSN:1065-657X    

DOI:10.1080/1065657X.1996.10737808

出版商:Taylor & Francis    

年代:1996

数据来源: Taylor

ISSN:1065-657X    

DOI:10.1080/1065657X.1996.10701813

出版商:Taylor & Francis    

年代:1996

数据来源: Taylor

摘要:

Three mixtures of ground yard trimmings (50 percent by volume in each mix), chicken manure (50, 27 and 40 percent) and potato processing, gelatin and bakery wastes were composted in four pilot-scale, 208 liter, insulated vessels (the first mixture was replicated). The mixes were obtained from a commercial composter and were studied both to obtain kinetic parameters for materials of this type and to help solve a problem of inconsistent maturity of product at the commercial operation. A 65°C set point controlled a high/low fan aeration system for each vessel. Temperature (at several points), air flow, oxygen consumption, carbon dioxide evolution and ammonia production were monitored. The vessels were weighed and materials were remixed twice each week during a four week composting period. At each remix, water was added to maintain a 50 percent by weight moisture content, and samples were taken for moisture content, volatile solids, chemical composition (including C:N ratio), pH and compost stability determinations. Results showed that C:N ratios were reduced from the 13 to 20 range, initially, down to 11 to 12 for all three mixes. Dry matter loss was from 31.6 to 33.7 percent for the different mixes (50 to 54 percent reduction in organic matter). Loss rate peaked at six percent/day on day 2 for mixes 1 and 3 and at three percent/day on day 11 for mix 2. Additionally, in the early, active portion of the process and at the low fan rate used, it was found that the system could go completely anaerobic in about an hour.

ISSN:1065-657X    

DOI:10.1080/1065657X.1996.10701814

出版商:Taylor & Francis    

年代:1996

数据来源: Taylor

摘要:

Chemical changes in extractable lipids from four mixtures of farmyard manures were investigated during the composting process. Lipid extractions with diethyl ether (DEE) and chloroform (CHCl3) were sequentially performed on samples collected at seven different times during composting. Amounts of DEE-extractable lipids decreased continuously during composting, while CHCl3-extractable lipids remained relatively constant.13C NMR and mass spectrometric data indicated that the lipids became chemically more homogeneous during composting and that biologically resistant molecules predominated at the end of composting.

ISSN:1065-657X    

DOI:10.1080/1065657X.1996.10701815

出版商:Taylor & Francis    

年代:1996

数据来源: Taylor

摘要:

Because of proposed bans on the landfilling and incineration of leaves, grass and brush, large-scale composting is fast becoming the primary disposal option for yard trimmings in many states. Few systematic studies have been done to compare the effects of turning regime, feedstock mix ratio, or windrow vs. pile configuration on composting and the characteristics of finished compost. In this study, various ratios of leaves, grass and brush were mixed and composted in two series of windrows; and one set of static piles. One windrow series (#1) was turned seven times every four weeks, while the other windrow series (#2), and the piles, were turned once every four weeks. The effects of the different treatments were examined by measuring compost temperature, oxygen concentration, pH, organic matter and moisture content, volatile fatty acid content, bulk density, stability, humification and seed germination indices, total and available nutrient levels, and particle size distribution. Results showed that turning frequency had little impact on oxygen concentrations, VFA content and temperatures during the composting of yard trimmings in windrows, however, in piles temperatures were substantially higher and oxygen concentrations fluctuated greatly. The composts from all the treatments were stable, (oxygen uptake rates < 0.1 mg O2/g OM/hr) after 60 days of composting regardless of the turning frequency, mix ratio or configuration. The bulk density inereased much more rapidly in frequently turned windrows than in the other treatments and particle sizes were smaller in these windrows. In most respects however, the final composts (day 136) were remarkably similar and none inhibited Cress seed germination or root elongation. The pH of all the composts, and the soluble salts and nitrate levels in composts made with high levels of grass, exceeded guidelines for greenhouse growth media.

ISSN:1065-657X    

DOI:10.1080/1065657X.1996.10701816

出版商:Taylor & Francis    

年代:1996

数据来源: Taylor

摘要:

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.

ISSN:1065-657X    

DOI:10.1080/1065657X.1996.10701817

出版商:Taylor & Francis    

年代:1996

数据来源: Taylor

摘要:

A conventional potting media containing peat moss, softwood bark and sand was amended to contain 0,25,50,75 and 100 (percent vol−1) municipal compost made from yard waste and biosolids. Each medium was adjusted with limestone and sulfur to an approximate pH of 5.0, 6.0 or 7.0.Rhododendron PanticumL. ‘Anah Kruschke’ (Rhododendron),Thujia occidentalisL. (Arborvitae) andRudbeckia hirtaL. ‘Goldilocks’ (Black-eyed Susan) were grown in each medium and pH level for 18 months. Leachate from pots was tested for NO3-N and NH3-N+NH4-N to determine how media pH and the amount of compost effected the potential for potting media to be a source of nitrate in surface and ground water.

ISSN:1065-657X    

DOI:10.1080/1065657X.1996.10701818

出版商:Taylor & Francis    

年代:1996

数据来源: Taylor

摘要:

A comparative study was run during 13 months on two biowaste definitions involving both lab tests and field surveys. A narrow biowaste definition, allowing only biogenic wastes (kitchen and garden waste) and referred to as ‘Biowaste,’ was compared to a broad biowaste definition, referred to as ‘Biowaste Plus’ and including man-made products, such as nonrecyclable wastepaper and diapers. Two similar test areas, each with about 425 inhabitants, were defined in a semiurban area north of Antwerp. During the entire test period, the amount of curbside waste (i.e., biowaste and restwaste or ‘grey waste’), was continuously measured and analyzed regularly (twice per season) for composition. At the start, middle and end of the test, the population of each test area was surveyed. Bench-scale aerobic composting experiments were run to evaluate the influence of both biowaste definitions on the composting process and the compost end product.

ISSN:1065-657X    

DOI:10.1080/1065657X.1996.10701819

出版商:Taylor & Francis    

年代:1996

数据来源: Taylor

摘要:

Use of composts as soil amendments to enhance crop growth requires a knowledge of rates and amounts of nutrients released. A greenhouse study was conducted using ryegrass (Lolium perenneL.) as a test plant to evaluate this release from composts. The experimental design consisted of four blocked replicates in a complete factorial with two types of compost (wastewater treatment plant biosolids and cow manure), four application rates (1, 2, 5 and 10 percent of weight of sand), and three fertilizer treatments (0, 100 mg N/kg mixture, and 100 mg P/kg mixture). Rye-grass top growth was harvested after 21 days. The regrowth was harvested three additional times. Roots were recovered after the fourth harvest. Total N uptake was significantly and positively affected by the total amount of N supplied by the compost or compost plus N fertilizer (r2values ranged from 0.992 to 0.999). Initial N uptake depended on the mineral N concentration in the compost and was higher from biosolids than from cow manure compost. Biosolids compost contained 10 times more mineral N and this N was primarily taken up in the first two harvests. Cow manure compost, however, provided N gradually over the entire 84 day test. In addition to N, both composts also supplied P, K, and other major and minor nutrients essential for plant growth.

ISSN:1065-657X    

DOI:10.1080/1065657X.1996.10701820

出版商:Taylor & Francis    

年代:1996

数据来源: Taylor

摘要:

Best design of a compost system is dependent on knowing the degradability of the waste. Although many bulking agents used to adjust moisture and porosity consist of organic matter, it is usually assumed they contribute only a small proportion of the total degradable material in a compost mix. As the microorganisms degrade the organic compounds during composting, it is generally presumed that they grow, and increase in biomass and numbers. In this study, bench-scale compost reactors were used to determine the relative contributions of sewage sludge and the bulking agent (pine sawdust) to the biodegradability of a compost mix. Although the overall level of microorganisms did not change markedly during composting, subpopulations able to degrade selected macromolecules were present at varying levels. Populations capable of degrading bacterial cell walls and thereby of contributing to recycle of inorganic nutrients through biomass turnover were present throughout the composting period.

ISSN:1065-657X    

DOI:10.1080/1065657X.1996.10701821

出版商:Taylor & Francis    

年代:1996

数据来源: Taylor