Pyrene mineralization capacity increases with compost maturity

Experiments were conducted to determine the effects of composting or simple addition of compost to the mineralization of n-hexadecane, pyrene and benzo(a)pyrene in soil. Soil (contaminated or clean) was composted with maple leaves and alfalfa. Samples from different composting phases were spiked with radiolabeled and cold n-hexadecane, pyrene or benzo(a)pyrene, placed in aerated microcosms at different temperatures, and monitored for mineralization. It was determined that neither composting nor the addition of compost had any effect on n-alkane or benzo(a)pyrene mineralization. In contrast, the pyrene mineralization rate increased dramatically with the amount of time that soil had been composted. Highest pyrene mineralization rates and extents (more than 60% after 20 days) were obtained when pyrene was in contact with composted soil from the curing stage. Neither thermophiles (55 °C) nor fungi were responsible for pyrene mineralization.     

The use of olive tree pruning waste compost to sequestrate methylene blue dye from aqueous solution

Considering that quality water supplies are diminishing and climate disorder affects water cycle, wastewaters should be decontaminated for reuse either by the same establishment or in agriculture for the growth of industrial plants. In that context, much research work has been focused on the development of low cost biosorbents. In this study, the effect of composting on the adsorption capacity of olive tree pruning waste (OTPW) biomass for methylene blue (MB) removal from aqueous solutions was examined. Composting procedure may improve the sorption properties of the raw organic materials, is economical and easy to apply. MB adsorption on both OTPW and composted olive tree pruning waste (COTPW) biomasses was found to be fast. The maximum monolayer adsorption capacity obtained from Langmuir isotherm was estimated to be 129.87 and 250.00 mg/g for OTPW and COTPW, respectively, indicating that composting procedure greatly improved the adsorptive properties of OTPW. The raise of temperature from 25°C to 60°C decreased the efficiency of OTPW for MB removal whereas the adsorption capacity of COTPW was not affected at high temperatures. Moreover, COTPW showed constant adsorption over the 2–8 solution pH range.     

Effect of pruning material compost on the nitrogen dynamic,soil microbial biomass,and plant biomass in different soil types

Landscape and Ecological Engineering - Compost prepared using pruning material (PM) contains a higher amount of mineralizable carbon (C) than conventional compost, readily causing nitrogen (N)...     

Use of pruning waste compost as a component in soilless growing media

The objective of this work was to study the use of pruning wastes compost (PWC) as a growing media component for ornamental plants. The main physical, chemical and biological characteristics of PWC were analysed in order to evaluate its suitability for use in soil-less cultivation. Six growth substrates were prepared by mixing PWC with peat (P), ground leaves (GL), sand (S) and spent mushroom compost (SMC) in different proportions. Two different pot experiments were carried out to test its characteristics of production using perennial ryegrass (Lolium perenne L.) and cypress (Cupressus sempervirens L.) as indicators and the different media as treatments. The growth experiments showed that PWC required mixing with a nutrient-richer material to produce higher results. Therefore, substrates containing SMC (PWC+P+SMC and PWC+SMC) seems to be the most adequate growing media. After the statistical analysis, we concluded that the PWC could be used as a growing media component.     

Chemical and physical properties of pruning waste compost and their seasonal variability

Selected chemical and physical properties of 12 different pruning waste compost (PWC) samples were evaluated to assess their suitability as substrates for ornamental plants. Samples were taken periodically from the same composting facility over 18 months in order to determine if there was any seasonal variability. In addition to the PWC samples, a Canadian Sphagnum peat and a commercial growing medium (CGM) were used as standard materials. With respect to PWC properties, pH values were above 8, significantly higher than the pH of peat and the commercial substrate. All samples showed adequate levels of organic matter and correspondingly high cation-exchange capacity (CEC) values. The C/N ratio varied between 22 and 48, significantly higher than the optimal values of 15-20. Although composts were sampled from piles established in different seasons, no significant differences were found in their chemical properties. However, water retention characteristics were affected by seasonal changes in components entering the facility. Comparing the properties of PWC to those of peat and commercial growing medium, this material appears to be an acceptable component of a substrate for container-grown ornamental plants.     

Carbon and nitrogen mineralization from decomposing gypsy moth frass

Defoliation of forests by insects is often assumed to produce a pulse of available nitrogen (N) from the decomposition of frass pellets. In this study we measured rates of carbon (C) and N mineralization from gypsy moth frass incubated with and without soil, and for soil alone. Incubations were at constant temperature and soil moisture conditions and lasted for 120 days. We found that gypsy moth frass contains much labile C as well as extractable N, and that the stimulation of microbial growth by the labile C results in immobilization of essentially all of the extractable N in the frass. The response of the microbes is fast, beginning within 1 day and lasting at least 90 days. This immobilization response represents an efficient mechanism for conserving N within a forest ecosystem after a defoliation event.     

Growth substrates made from duck excreta enriched wood shavings and source-separated municipal solid waste compost and separates: physical and chemical characteristics

Production and use of compost is an effective means to reduce wastes, and offers a large potential as growth substrates and source of nutrients. The objective of this study was to determine the physical and chemical characteristics of duck excreta enriched wood shavings (DMC) and source-separated municipal solid waste (MSW) composts and separates, and to assess the physical characteristics of growth substrates made from these two composts and selected substrates. MSW compost separates were the following sizes: F1 > 4 mm diameter, 2 mm < F2 < 4 mm, 1 mm < F3 < 2 mm and F4 < 1 mm. Growth substrates were prepared by mixing DMC and F2 and F3 MSW separates (M/M ratios). Growth substrates A-E consisted exclusively of 10-60% DMC and 20-60% of MSW separates F2 and F3. Growth substrates F-J, and K-O were the same as substrates A E, with 15% M/M brick fragments or shredded plastic added as porosity agents, respectively. Growth substrates (BE/S) made of black earth (BE) and sandy loam soil (Ls) in a 1:4 (M/M) ratio, commercially available peat substrate (Pr) and an in-house sphagnum peat-based substrate (Gs) were used for comparison. Principal component analysis (PCA) showed that DMC was a better material than MSW with respect to porosity and water field capacity. MSW compost and separates differed by their relatively high levels of water-soluble and HCl-hydrolyzable N and increased advantageous water retention capacity. PCA also showed that substrates A-E exhibited porosity and water field capacity similar to those of Pr. Substrates F-J had porosity and water field capacity similar to those of BE/S, whereas substrates K O were more similar to Pr and to substrates A and B. The presented data indicate that DMC and MSW separates were complementary in providing good physical and chemical characteristics to the growth substrates.     

The non-nutritional performance characteristics of peptones made from rendered protein

Economic considerations require the use of inexpensive feedstocks for the fermentative production of moderate-value products. Our previous work has shown that peptones capable of supporting the growth of various microorganisms can be produced from inexpensive animal proteins, including meat and bone meal, feather meal, and blood meal, through alkaline or enzymatic hydrolysis. In this work, we explore how these experimental peptones compare to commercial peptones in terms of performance characteristics other than chemical make-up; these characteristics can impact fermentation operating cost. It is shown that experimental peptone powders produced through enzymatic hydrolysis are highly hygroscopic and that their physical form is not stable to humid storage conditions; those produced through alkaline hydrolysis and commercial peptones are less hygroscopic. When used in growth medium, all peptones contribute haze to the solution; experiments show that the source of haze is different when using enzyme- versus alkali-hydrolyzed peptones. Alkali-hydrolyzed peptones and all peptones made from blood meal are stronger promoters of media foaming than the commercial peptones; some enzyme-hydrolyzed peptones support very little foam formation and are superior to the commercial peptones in this sense. Alkali-hydrolyzed peptones are roughly equivalent to commercial peptones in the coloration they contribute to media, while enzyme-hydrolyzed peptones contribute intense coloration to media. No peptone caused a significant change in the viscosity of media. The experimental peptones studied here may be acceptable low-cost substitutes for commercial peptones, but none is equivalent to the commercial products in all respects.     

Carbon mineralization in the southern Sonoran Desert

We measured carbon mineralization in four different desert habitats (Arroyos, Hillsides, Canopies-Plains and Open-Plains) and the separate effect of litter addition from annual and perennial plants on soil microbial respiration using two laboratory soil incubation experiments. The differences in total aboveground phytomass among habitats correlates with soil nutrient content, soil particulate organic matter (POM) and consequently, C mineralization. The Arroyos habitat with the highest perennial plant phytomass and litter production, had the highest soil nutrient content, soil POM and C mineralization. Litter from annual plants had twice the P concentration than litter from the perennials, but only half the N concentration. Soil microbial respiration was higher with annual plant litter than with perennial plant litter in the Hillsides and Canopies-Plains, suggesting that microbial activity in both habitats was improved by litter with a higher C quality. In contrast, in the poorest habitat, the Open-Plains, the better response to the addition of perennial plant litter suggests that microbial activity may have been constrained by N input.     

生活垃圾堆肥基质草坪建植体系接种草坪土壤线虫多样性特征

通过城市生活垃圾堆肥基质草坪建植体系接种草坪土壤线虫,研究了线虫数量、科属分类、营养类群等线虫多样性变化.结果表明,接种草坪土壤线虫 4 个月后,垃圾堆肥基质中共鉴定出线虫4科7属,包括植物寄生性线虫、食真菌线虫和食细菌线虫3个营养类群;垃圾堆肥基质草坪建植体系中线虫总数明显少于土壤基质.在接种草坪线虫的土壤基质草坪建植体系中,植物寄生线虫为优势营养类群,盘旋线虫属仍为优势属,相对多度达到83.3%,显著高于本底土壤45.1%.在接种草坪土壤线虫的垃圾堆肥基质草坪建植体系中,土壤本底中处于优势属的植物寄生类线虫如盘旋线虫属和螺旋线虫属基本消失了,表明垃圾堆肥基质对植物寄生类群的生长与繁殖表现出明显的抑制作用,优势属也发生了很大变化,食细菌类群的头叶属和丽突属成为优势属,相对多度分别为67.0%和14.0%.因此,从草坪土壤线虫危害角度来说,以垃圾堆肥作为草坪基质将会为草坪植物生长创造良好的基质环境.     

生活垃圾堆肥淋洗液培植无土草皮的生态特征

以生活垃圾堆肥淋洗液培植无土草皮,结果表明,垃圾堆肥淋洗液中有机质、全氮、有效磷及其它营养元素含量显著高于对照土壤淋洗液,能够充分满足草坪植物生长需要。高浓度淋洗液使黑麦草和高羊茅种子萌发高峰期推迟出现,但不影响发芽率,到萌发第11天,种子发芽率分别达到94％和92％以上。对黑麦草而言,80％的淋洗液可显著提高植株高度、地上生物量和叶绿素含量;对高羊茅,60％的淋洗液则为最佳浓度。当淋洗液培植的无土草皮进行田间铺坪90d时,黑麦草和高羊茅草皮地上生物量分别达到5．38g／块和7．89g／块,并显著高于对照草皮（P〈0．05）,而地下生物量和根长差异不显著。垃圾堆肥淋洗液改变了黑麦草和高羊茅植株地上／地下生物量的分配格局,使其根冠比降低,其分别为4．60和3．71,并明显低于对照。从坪用性状上看,铺坪后垃圾堆肥淋洗液培养的草皮叶色深绿,质地柔软光滑,明显优于土壤淋洗液培养的对照草皮。     

Evaluating the quality of communities made compost manure in South Africa: a case study of content and sources of metals in compost manure from Thulamela Municipality, Limpopo province

The main aim of this research was to assess the quality of the compost manure of a community project which is part of Government's initiative for job creation. This was done by determining the sources, presence and concentrations of metals in the composting materials and compost manure. Generally, there are many communities involved in making compost manure with no assessment of the quality of the compost. This is because no quality assurance guidelines are in place. The main source of heavy metals in the composting materials was found to be sawdust while cabbage was the main source of the essential nutrient elements such as magnesium calcium and potassium. The level of heavy metals in all the compost materials were found in the following order: Fe>Mn>Cr>Ni>Zn>Cu>Co>Cd. The level of essential elements was in the following order: Ca>Mg>K>S>Na>Li>Si>P. The level of heavy metals in the compost materials reflected the level in the final compost manure. The concentration of metals in the compost materials and compost manure was below the international standards of compost manure. Therefore, compost manure can be said to be of good quality. However, sawdust was found to be not a good compost material as it was the source of main heavy metals.     

Effect of initial physical characteristics on sludge compost performance

To develop an active microbial activity quickly developing stabilizing thermophilic temperatures during the composting of wastewater sludge, the bulking agent (BA) plays a major role in establishing the recipe structure, exposed particle surface area and porosity. To optimize the biodegradation of a sludge compost recipe, the objective of this paper was to study the effect and interaction of initial moisture content (MC) and BA particle size distribution. Three 300 L insulated laboratory composters were used to treat two series of ten (10) recipes with different combinations of MC and BA particle size distribution. Using a to wastewater sludge to BA dry mass ratio of 1/6, the ten (10) recipes were repeated using two BA, residues recycled from a commercial sludge composting plant and crushed wood pallets. Each four week trial monitored O₂ uptake, temperature, compost consolidation and airflow distribution. The Central Composite Factor Design method produced a model from the results estimating the impact of a wider range of MC and BA particles size distribution. The MC directly affected the total O₂ uptake and therefore, organic matter biodegradation. The BA particle size distribution influenced compost consolidation with a MC crossed effect. Both BA particle size distribution and MC influenced compost airflow dispersion. Composting was optimized using the BA consisting of recycled green waste residues with particle size of 20–30 mm and a 55% MC. The predictive models suggested the need for further optimization of sludge and wood residue composting recipe.     

Successive rapid reductive dehalogenation and mineralization of pentachlorophenol by the indigenous microflora of farmyard manure compost

AIMS: To determine whether composting with animal manure can be used to effectively remediate soil from a pentachlorophenol (PCP)-contaminated site, and to establish the fate of the degraded xenobiotic. METHODS AND RESULTS: Contaminated soil from a sawmill site was mixed with farm animal manure and composted in a 0.5 m3 silo under fully aerobic conditions. The disappearance and fate of PCP was monitored by gas chromatography (GC-ECD) and extensive mineralization confirmed in experiments with 14C-radiolabelled PCP. The disappearance of PCP was rapid and virtually complete within 6 days, prior to the onset of thermophilic conditions. Dechlorination of the PCP was found to be both reductive and sequential. CONCLUSIONS: PCP removal from contaminated soil by aerobic composting with animal manure is efficient and proceeds via reductive dechlorination to virtually complete mineralization. This contrasts with other chlorophenol composting regimes in which mineralization is achieved but dechlorination intermediates do not accumulate to detectable levels. SIGNIFICANCE AND IMPACT OF THE STUDY: The results of this study demonstrate that anaerobic reductive dechlorination can proceed in an aerobic composting environment and contribute to efficient pentachlorophenol removal. Farmyard manure composts may represent a rapid, low-cost, low-technology option for treatment of chlorophenol-contaminated soils.     

Carbon and nutrient mineralization and fungal spore composition of fecal pellets from voles in Minnesota

Numerous investigators have suggested that small mammals may regulate ecosystem processes because they couple producers and decomposers through deposition of fecal matenals and by dispersing spores from mycorrhizal symbiotic fungi We investigated carbon nitrogen, and phosphorus mineralization rates from feces of two arvicoline rodents, Clethrionomn gapperi and Microtus pennsylianicus common in the forests of the Lake Superior region We also examined fungal spore composition from these feces Mineralizable pools of C and N and their decay rates were higher in feces from C gapperi than from M pennsvhamcus , but there were no differences in sizes of mineralizable pools of phosphorus Feces of C gapperi contained four times more fungal spores than those of M pennsylvanicus Twenty-three fungal genera were represented in these feces, and all but one genus have predominantly ectomycorrhizal forms Fungal species composition also differed significantly between the two arvicoline species Although the amount of N and P mineralized annually from populations of these two species is small compared with nutrient budgets for the forests as a whole, these species may be important in dispersing spores and labile nutrient pools to microsites of seedling establishment     

Bioremediation potential of basidiomycetes isolated from compost

The potential of a consortium of three basidiomycete mycelia isolated from compost to degrade polycyclic aromatic hydrocarbons (PAH) was first evaluated using a test based on decolorization of Poly R-478 dye. When pre-grown on straw, the consortium decolorized the dye by 83% in 7 days and generated a laccase activity of 663 IU l(-1). Its ability to degrade naphthalene was investigated in soil microcosms specially suited for this volatile PAH. The kinetic study was conducted at a maximal naphthalene concentration of 500 mg kg(-1) of soil. Naphthalene concentration, CO(2) evolution and phytotoxicity (germination index, GI%) on Lepidium sativum seeds were monitored. The naphthalene concentration decreased by about 70% in three weeks in the presence of metabolic activity, while the GI% increased indicating reduced phytotoxicity.     

垃圾堆肥基质对不同草坪植物生态及质量特征的影响

通过田间实验,研究了城市生活垃圾堆肥基质对高羊茅和黑麦草不同品种草坪植物生态及质量特征的影响。结果表明:堆肥能明显促进草坪植物生长,提高地上和地下生物量。与一茬草相比,垃圾堆肥对二茬草的促进作用更为明显,说明了垃圾堆肥营养具有缓释效应。另外,垃圾堆肥能加快草坪植物返青,对越年草坪植物盖度、株高以及生物量具有明显促进作用。不同品种草坪植物对垃圾堆肥的生长响应存在明显差异,在生长速度和生物量指标上,3种高羊茅品种表现较好。采用美国国家草坪评比体系NTEP(9分法)作为评比标准,对各草坪综合质量进行评定。结果垃圾堆肥建植的草坪综合质量均明显好于对照;不同草坪植物之间比较,以爱神综合质量为最佳,尤其表现在密度、颜色和质地方面。