首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
城市污泥与调理剂混合堆肥过程中有机质组分的变化   总被引：5，自引：4，他引：1  
【目的】研究城市污泥堆肥过程中各项有机质组分及碳、 氮在堆肥过程中的形成与转化,以期改善堆肥的生物有效性,促进其土地利用。【方法】在工厂规模化下,以城市污泥、 蘑菇渣锯末以及返混料按照6∶3∶1的质量比混合形成堆肥物料,辅以强制通风措施和翻抛,进行为期18 d的高温堆肥试验。堆肥期间定期采样,测定指标包括温度、 C/N值、 pH、 含水率、 有机质降解率、 水溶性组分、 半纤维素、 纤维素和木质素,研究堆肥期间不同阶段堆肥物料中有机质组分的动态变化。【结果】堆体温度随着发酵时间的延长呈现先升高后降低的趋势,最高温度达到71.3℃; 含水率由60.7%降低到51.4%,pH呈现先升高后降低的趋势,总体处于6.0~7.5之间; 总有机碳含量持续下降,氮素含量表现为高温期持续下降随后呈上升的趋势; 初始阶段,堆肥物料中四种成分含量分布为: 水溶性组分纤维素半纤维素木质素,至堆肥结束变化为: 纤维素水溶性组分木质素半纤维素,经过堆肥之后水溶性组分及半纤维素含量分别由39.5%和20.1%下降为27.9%和14.4%,纤维素含量由初始的21.8%上升至29.5%,木质素含量相对稳定不变。物料经过堆肥化处理后达到腐熟标准,水溶性组分和半纤维素含量分别降低了38.6%和38.8%,纤维素和木质素含量在高温期分别降解了11.7%和18.5%; 物料总量降低了9.8%。水溶性组分的主要降解阶段为高温期,期间降解部分占总降解量的65.5%; 半纤维素的主要降解阶段为稳定期,稳定期降解部分占总降解量的69.1%,且有继续降解的趋势; 纤维素和木质素仅在高温期有少量降解; 氮素则表现为高温期铵态氮的损失及稳定期硝态氮的积累。【结论】堆肥化处理在实现污泥减量化基础上,污泥中有机质得到了稳定化,有利于城市污泥的土地利用。  相似文献   

2.
Li  Guoxue  Zhang  Fushuo  Sun  Ying  Wong  J. W. C.  Fang  Ming 《Water, air, and soil pollution》2001,132(3-4):333-345
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.  相似文献   

3.
Loss of mass and volume during composting of various feedstocks is an important consideration for compost operation management and facility design. Direct measurements of mass and volume in piles and windrows require specialized equipment and skills that render such measurements impractical for most commercial operations. A study was undertaken to develop a technique for calculating reductions in mass and volume during composting based on the change in concentration of an internal standard and bulk density measurements. Of the various physicochemical parameters investigated, nonvolatile solids (NVS) content proved the most reliable internal standard because of its strong inverse correlation with organic C (r2 = ?0.95) and low coefficient of variation (CV = 0.15). Reductions in mass and volume during composting of six windrows comprised of various feedstocks were then calculated using initial and final measurements of NVS and bulk density. Reductions in mass averaged 19.4% of initial mass and ranged from 11.5% to 31.4%. Volume reductions were substantially greater than mass losses, and averaged 40.7% of initial volume. Change in mass was used in combination with organic C contents to calculate the loss of organic C. These losses averaged 28.9% and represented an average 46.4% of total mass loss. Equations for calculating reductions in mass, volume and organic C are presented. These equations may be easily modified to calculate the loss of any measured constituent of compost where the initial and final concentrations are known.  相似文献   

4.
A batch anaerobic composting process was investigated to evaluate the potential for biogas recovery from animal manure under the worst scenario of high initial solids and non-well adapted microorganisms. The effects of composting time and initial total solids content on biogas recovery and reduction of solids during anaerobic digestion of swine, poultry and beef manure were studied. Volatile solids reductions averaged 10% or less over a 30-day period for all initial solids contents, which was considerably lower than expected. Reductions in VS increased slightly as initial solids content in the reactor decreased. Reductions in COD were somewhat higher than for VS. The pH values were fairly stable during the composting experiments and within the range suitable for anaerobic digestion. Decreases in TKN and ammonia nitrogen during the process were insignificant, and greater decreases were observed for lower initial solids content in the reactors. Cumulative biogas production increased with decreasing solids content in the reactor for all types of manure. For the lowest initial solids contents (12-14%), swine manure produced more biogas, but at the higher initial solids contents there was little difference among the manure types. Biogas yields were about 0.5 m3/kg VS consumed for the lowest solids contents; however, yields were only about 0.2 m3/kg VS consumed for the higher initial solids. Methane content of the biogas samples averaged 49%. Based on these results, it appears that adapting microbial populations in the high solids feedstock may obtain reasonable biogas production rates and VS reduction during anaerobic digestion. Although some differences in results among the three types of manure were noted, they were not large and likely would not be significant with adapted microbial populations.  相似文献   

5.
尿素硝酸铵调节碳氮比促进小麦秸秆堆肥腐熟   总被引：3，自引：0，他引：3  
【目的】高温堆肥可以加快秸秆腐解并浓缩其养分含量,是秸秆综合利用的有效措施之一。通常采用畜禽粪便来调节秸秆堆肥的C/N比,但由于重金属和抗生素问题限制了其在高价值经济作物上的应用。为此选择绿色无污染的尿素硝酸铵溶液(UAN)作为氮素调理剂开展堆肥试验,为生产高品质秸秆有机肥提供科学依据。【方法】设置4个处理,按照UAN添加量由多到少分别将堆肥C/N调节为15、20、25和30,进行50d堆肥,监测堆肥过程中温度、pH、EC、有机碳、铵态氮、硝态氮、纤维素组成、种子发芽率指数等指标的动态变化,并综合判定堆肥腐熟效果。【结果】C/N25和C/N30的处理最高温度分别达到63.4℃和65.9℃,50℃以上高温持续时间分别为7d和8d,而C/N15、C/N20处理高温持续仅1~2d,未达到无害化处理要求。堆肥初始pH值随着UAN添加量的增大而升高,范围在6.79~7.94,堆肥后pH值范围在7.63~7.89,各处理间没有明显差异。堆肥后各处理有机碳含量下降了8.29%~13.5%,且C/N25、C/N30的处理有机碳降解率显著高于C/N15和C/N20的处理。全氮含量较堆肥初增加53.3%~83.7%。秸秆中有机物组成表现为纤维素>半纤维素>木质素,堆肥后半纤维素、纤维素和木质素含量分别较堆肥初下降了30.5%~50.9%、42.%~55.8%和15.3%~29.4%。堆肥过程中由氨气挥发造成的氮素损失率随着C/N比升高而降低,分别为34.9%、29.0%、22.1%和7.37%;堆肥过程中无机氮占总氮的比例逐渐降低,由初始的52.4%~75.8%下降到结束时的25.4%~63.1%,而对应有机氮的比例则较堆肥初提高了52.4%~66.0%,表明小麦秸秆堆肥中氮素的稳定性增强。经过50d的堆肥处理,C/N25和C/N30的处理种子发芽率指数均达到彻底腐熟(GI≥80%),C/N20的处理达到基本腐熟(GI≥50%),而C/N15的处理未腐熟。【结论】采用尿素硝酸铵溶液作为氮素调理剂可有效降低小麦秸秆堆肥C/N比,促进小麦秸秆腐解,以C/N30处理腐熟效果最好。  相似文献   

6.
This study investigated the performance of composting cornstalks after used as the filtering materials for the pretreatment of anaerobically digested manure centrate. Results show that cornstalks could effectively remove suspended solids and organic matter in digested centrate. Direct composting of the used cornstalks could be achieved. The composting temperature increased rapidly and maintained at the thermophilic phase for more than 10?days. During 28?days of composting, the used cornstalks could be mature as indicated by the matrix pH of 7.37, electrical conductivity of 1.13?mS/cm, and germination index of higher than 100%. During composting, the carbon/nitrogen ratio of the used cornstalks decreased from 16.81 to 13.62. Moreover, cellulose in the used cornstalks was degraded by approximately 35.4% during composting.  相似文献   

7.
Composting has become an increasingly popular manure management method for dairy farmers. However, the design of composting systems for farmers has been hindered by the limited amount of information on the quantities and volumes of compost produced relative to farm size and manure generated, and the impact of amendments on water, dry matter, volume and nitrogen losses during the composting process. Amendment type can affect the free air space, decomposition rate, temperature, C:N ratio and oxygen levels during composting. Amendments also initially increase the amount of material that must be handled. A better understanding of amendment effects should help farmers optimize, and potentially reduce costs associated with composting. In this study, freestall dairy manure (83% moisture) was amended with either hardwood sawdust or straw and composted for 110-155 days in turned windrows in four replicated trials that began on different dates. Initial C:N ratios of the windrows ranged from 25:1 to 50:1 due to variations in the source and N-content of the manure. Results showed that starting windrow volume for straw amended composts was 2.1 to 2.6 times greater than for sawdust amendment. Straw amended composts had low initial bulk densities with high free air space values of 75-93%. This led to lower temperatures and near ambient interstitial oxygen concentrations during composting. While all sawdust-amended composts self-heated to temperatures >55°C within 10 days, maintained these levels for more than 60 days and met EPA and USDA pathogen reduction guidelines, only two of the four straw amended windrows reached 55°C and none met the guidelines. In addition, sawdust amendment resulted in much lower windrow oxygen concentrations (< 5%) during the first 60 days. Both types of compost were stable after 100 days as indicated by CO2 evolution rates <0.5 mg CO2-C/g VS/d. Both types of amendments also led to extensive manure volume and weight reductions even after the weight of the added amendments were considered. However, moisture management proved critical in attaining reductions in manure weight during composting. Straw amendment resulted in greater volume decreases than sawdust amendment due to greater changes in bulk density and free air space. Through composting, farmers can reduce the volume and weights of material to be hauled by 50 to 80% based on equivalent nitrogen values of the stabilized compost as compared to unamended, uncomposted dairy manure. The initial total manure nitrogen lost during composting ranged from 7% to 38%. P and K losses were from 14 to 39% and from 1 to 38%, respectively. There was a significant negative correlation between C:N ratio and nitrogen loss (R2=0.78) and carbon loss (R2=0.86) during composting. An initial C:N ratio of greater than 40 is recommended to minimize nitrogen loss during dairy manure composting with sawdust or straw amendments.  相似文献   

8.
Amount and distribution of nitrogen in fulvic-, humic- and silico humic acids from a garbage-sewage sludge compost During the course of composting for 106 days of a mixture of solid wastes and sewage sludge subsamples were taken at different time intervals. They were extracted for fulvic-, humic- and silico-humic acids which in turn were fractionated for different nitrogen fractions. Basic nitrogen fractions such as amino acids (AS), amino sugars (AZ), real amide nitrogen (ADe), pseudo amide nitrogen (ADp), remainder nitrogen of the hydrolysate (RNHY) and total nonhydrolyzable nitrogen (ΣNnhy) have been determined. The most pronounced transformations of nitrogen within the organic matter of the compost took place during the first 10–14 days of composting.  相似文献   

9.
The succession of responsible microbiota during the composting process of rice straw (RS) was studied for 145 d in relation to the changes in the organic constituents of RS. During the composting process, the C / N ratio of RS decreased from 56 to 22. On a C basis, the relative contents of lipid, water-soluble organic matter (WSOM), hemicellulose, cellulose, and lignin fractions in RS changed from 5.6, 8.9, 32.9, 17.9, and 34.0%, to 7.3, 5.8, 30.7, 3.8, and 51.1%, respectively, indicating that the cellulose fraction was mainly decomposed in the composting process. Biomass C accounted for 18.3% (on day 75 when the total amount of phospholipid fatty acids (PLFAs) reached a peak) and 11.5% (at the end of composting) of the total C of RS under the composting process. As for PLFAs, the biomarkers of fungi and Gram-negative bacteria predominated in the RS material used. At the thermophilic stage (the first 2 weeks), biomarkers of Gram-positive bacteria and actinomycetes predominated. After the thermophilic stage, biomarkers of other Gram-positive bacteria became dominant. Finally, at the curing stage, the proportion of the biomarkers of Gram-negative bacteria and eukaryotes increased, indicating the co-contribution of Gram-positive and Gram-negative bacteria and fungi in the decomposition process at this stage. The trans / cis ratio of 16 : 1ω7 PLFA of RS under the composting process ranged from 0.18 to 0.30, indicating that the composting process of RS prepared a significantly lower environmental stress (p < 0.01) compared to the decomposition of RS in a submerged paddy soil.  相似文献   

10.
Precipitation that falls on compost sites picks up organic material from the windrows and the composting pad. The resulting runoff can contain high levels of nutrients, suspended solids, and organic matter, making it unsuitable for direct release into a receiving water body. Many jurisdictions require that the runoff from these sites be collected in a detention pond. Unfortunately, some of the recommended or required procedures for quantifying the volume of runoff from these sites are based on archaic or inappropriate hydrologic models. The development of better hydrologic models for open composting operations has been hampered by a lack of basic information regarding rainfall/runoff relationships at windrow composting sites. In this paper, a standard hydrologic model — the unit hydrograph method – is used to model the hydrology of a small, paved composting site. The model results compare well with field data collected at the site over a six month period. The volume of runoff predicted by the model was within 5% of the measured runoff volume for each of seventeen runoff events observed at the site over the study period. The results suggest that other industry standard hydrologic models can be adapted for use at open composting sites to account for the presence of large quantities of organic material on the site.  相似文献   

11.
麦秆和羊粪混合高温堆肥腐熟进程研究   总被引：14，自引：0，他引：14  
试验研究了添加不同比例的麦秆对羊粪高温堆肥腐熟进程的影响。结果表明, 羊粪高温堆肥时添加麦秆可缩短进入高温发酵阶段的时间, 减少氮素损失, 加快C/N降低速率。在堆肥过程中, 高温发酵层从中间向上下扩散; 有机质的下降速度在堆肥初期与麦秆比例呈正比, 在堆肥后期呈反比。堆肥结束时, 各处理堆肥全磷、全钾、速效磷和速效钾含量分别较堆肥初期提高2.29%~8.41%、12.51%~24.88%、1.77%~31.34%和5.03%~25.45%, 其中羊粪与秸秆6︰4处理的增幅均为最高; 速效氮含量较堆肥初期下降34.62%~14.10%, 其中6︰4处理降幅最小。在实际应用中, 羊粪与麦秆按体积比6︰4进行堆肥较为适宜, 腐熟速度最快, 若以种子发芽指数80%作为堆肥腐熟的评价指标, 则其腐熟速度比纯羊粪提高1倍, 28 d即可腐熟。  相似文献   

12.
NaOH处理玉米秸秆厌氧生物气化试验研究   总被引：28，自引：2，他引：28  
提出通过NaOH化学处理以改善玉米秸秆的可生物消化性能、提高玉米秸秆厌氧消化产气量的方法。NaOH添加量为玉米秸秆干物质的8%。对未处理和经NaOH处理的玉米秸秆进行了厌氧消化对比试验研究,厌氧消化负荷率为35,50,65和80 g/L。分析并比较了两者在不同负荷率下的日产气量、累积产气量、单位TS和VS产气量等。结果显示,与未处理玉米秸相比,NaOH处理过的玉米秸的干物质消化率和产气量明显提高,在35,50,65,80 g/L负荷率下,产气量分别提高了13.1%,39.8%,48.3%和47.8%,单位TS、VS的产气率分别提高了13.1%～48.3%、23%～61.3%;两种玉米秸分别在35和65 g/L负荷率下获得了最高单位TS产气量。NaOH化学处理使玉米秸细胞壁结构和化学成分发生了明显的变化,分别有53.2%、46.9%和66.6%的木质素、纤维素和半纤维素被分解,其中1/2～2/3被转化成了易被厌氧菌利用的可溶性物质,这是产气量提高的主要原因之一。研究结果对提高玉米秸的产气效率、实现大规模应用具有重要指导意义。  相似文献   

13.
A laboratory method was developed to quantify CO2, NH3 and VOC yields and to follow solids decomposition during composting of MSW or its components. All organic substrates were shredded, water and nutrients were added to near optimum levels prior to composting, and composting was continued until feed materials reached approximately the full extent of decomposition. Twenty five L stainless steel digesters were used and aluminum packing was mixed with the wastes to facilitate airflow. Thermophilic temperatures were maintained and air supplied in excess. Nutrients were added to reach an initial C/N ratio of approximately 30. CO2 and NH3 gases in the exit air stream were captured in alkaline and acidic solutions, respectively, and quantified through titration on a cumulative basis. VOC traps, prior to the gas traps, captured emitted volatile organic compounds, which were quantified on a cumulative basis. Solids were analyzed for hot water soluble matter, fats and lipids, cellulose, hemicellulose and lignin/humus. Food wastes, yard wastes and mixed paper produced approximately 368, 220 and 153 g C-CO2/dry kg and approximately 40.5, 4.6 and 2.0 g N NH3/dry kg of starting material, respectively. VOC volatilization profiles had a decreasing trend with composting. Partially composted MSW produced 8.2 mg/dry kg of 8 selected VOCs. CO2, NH3 and VOC recovery tests resulted in efficiencies of 98.6%, 97.6% and 94.6% respectively. Reproducibility of the solids decomposition and gaseous emissions measurements was observed. Carbon and nitrogen mass balance closures ranged from 85.5% to 117.1% and 32.2% to 175% respectively.  相似文献   

14.
The development of humic substances in the course of four composting processes was monitored quantitatively, recording both relative and absolute contents. Relative data showed contrasting results if the humic substances (HS) were related to the dry matter (d.m.) or to volatile solids (VS). Humic substances were apparently formed because of a concentration effect due to organic matter degradation. If absolute contents were considered, a decrease in the humic substances was observed, above all in the early stages of the process, due, probably, to degradation of the organic material, such as proteins, carbohydrates and lipids, coextracted with the humic substances. Processing of the data in respect of humic substance content over 13 composting processes and one study on the degradation of plant residues in soils, confirmed that no net humic substances are formed during composting and that the humification should be interpreted merely as degradation of the organic matter associated with the humic substances, after uncovering what is known as the core of the humus. The concept of humification during the composting process therefore needs to be reviewed, bearing in mind that neither the method commonly used for humic substance extraction nor the relative results obtained enable it to be interpreted satisfactorily.  相似文献   

15.
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.  相似文献   

16.
The organic matter in soils may be stabilized by its interactions with minerals. We have studied such interactions in a Haplic Alisol under forest in which clay and organic matter have migrated from an eluvial A horizon to accumulate in an illuvial B horizon. We have tried to trace the fate of organic matter in these horizons (Ah and Bvt) by determining clay mineralogy, carbon and nitrogen content, hydrolysable amino acids, lignin signature by alkaline CuO oxidation and carbon species by 13C CPMAS NMR of bulk soils and particle‐size fractions. In both horizons, most of the organic matter was present in O–alkyl and methylene structures, each contributing one‐third to the bulk organic matter. In the Ah horizon the ratios of carbon‐to‐nitrogen, and yields for lignin and hydrolysable amino acids decreased as the particle‐size class decreased, but side‐chain oxidation of lignin compounds increased with decreasing particle size. In contrast to previous observations, the proportions of O–alkyl carbon increased as particle size decreased, constituting a major proportion of the organic carbon in the clay‐size fractions from both the Ah and Bvt horizons (≥ 38%), while proportions of methylene carbon decreased. Illite was the dominant mineral in the fraction ≤ 6 μm, whereas the mobile fine clay fraction (<0.2 μm) was rich in smectites – minerals with large surface areas. Our results support the hypothesis that potentially labile organic matter, such as O–alkyl carbon typically present in polysaccharides, may be stabilized against further degradation in organomineral complexes.  相似文献   

17.
Empty fruit bunches (EFB), coffee grounds (CG), and palm oil mill sludge (POMS) were composted in the laboratory for 60 days in order to study the composting process of lignocellulosic food industry wastes. In the first part of the experiment, EFB, CG, and POMS were composted alone (composting of single lignocellulosic material), and in the second part, EFB was composted with CG (1EFB:1CG ratio) and POMS (1EFB:1POMS ratio). The effects of different turning frequencies on the physical and chemical properties of composting were observed and its relation with the degradation process was highlighted. Results showed that oil and grease were first degraded, followed by recalcitrant compounds like alpha-cellulose, hemicellulose, and lignin. Cellulose and hemicellulose were degraded mainly during the 60 days of composting, and the progressive reduction of the cellulose/lignin ratio proved that the main evolution of these wastes took place. It was observed that 3, 6, and 9 days of turning frequency did not affect the physicochemical properties of the compost. Composting EFB alone failed to achieve the required quality of maturity compost within 60 days, while CG and POMS recorded low in biological activity. Better results were shown in composting of EFB mixed with coffee grounds and POMS, the C/N ratio dropped to less than 20 by the 8th week of the composting period. Composting of mixed lignocellulosic materials showed larger changes compared to composting of single lignocellulosic material, reaching a C/N ratio below 20 within 8 weeks.  相似文献   

18.
易降解有机质含量对黄瓜秧堆肥腐熟和氮损失的影响   总被引：5，自引：4，他引：5  
蔬菜废弃物无害化处理,尤其对于集约化蔬菜产地,缺乏适用技术,易污染环境,浪费资源,甚至造成后续安全隐患。为实现蔬菜废弃物的安全高效转化,该试验以黄瓜秧为堆肥主原料,以玉米秸秆、淀粉和尿素为调理剂,在控制混合堆肥物料初始碳氮比为25,物料水分质量分数为60%,总物料质量相同的条件下,分析易降解有机质(除木质纤维素之外的有机质)比例对堆肥腐熟进程和氮素损失的影响。试验设置添加易降解有机质的质量分数分别为27%(T1)、36%(T2)、45%(T3)、51%(T4)4个处理,利用自制密闭式堆肥反应器研究了随堆肥进行,不同处理温度、物料损失、有机质降解和二氧化碳释放、p H值、电导率(electrical conductivity,EC)、发芽率指数(germination index,GI)的变化情况,并同时分析了氨气挥发速率、累积排放量和氮素损失率等。研究结果显示:随着初始混合物料中易降解有机质的增加,堆体的最高温度呈现出先升高后降低的趋势,但根据物料的p H值、EC和GI值判断,易降解有机质比例过高会影响堆肥的腐熟过程,其比例不宜超过45%,其中T3的最高温度最高,高达71.4℃,且有机质减少量和CO2累积排放量最高,表明T3最利于堆肥的起爆反应和无害化目标的实现;然而,易降解有机质的增加会伴随氮素损失,尤其是氨气挥发损失量的增加,其中T3氨气损失累积量最大(380.29 mg),T4的氮素损失率最高(36.01%),即物料中的木质纤维素有利于减少氮素的损失。综上,物料中易降解有机质质量分数为45%最利于堆肥的高温实现,同时对腐熟的影响较小,但氮素损失率高,因此实际生产中可额外添加木质纤维素类膨胀剂,改良物料的物理结构和理化特点,从而在实现高温的基础上减少氮素的损失。  相似文献   

19.
As interest in food waste composting grows, so does the need for proven composting methods. Stability testing has been proposed as a compost quality assurance tool. We conducted this study to: (i) to evaluate the efficacy of simple outdoor composting methods in producing a compost with a low, stable decomposition rate, and (ii) to determine the reliability of simple, 4-h compost stability evaluation methods. Composting was conducted outdoors in winter and spring in Eugene, Oregon without moisture addition. Mixed food waste was combined with screened dairy solids and ground yard trimmings. Sawdust was used to cover windrows for the first 27 d of composting. Compost windrow temperatures remained above 55°C for 30+ d. Carbon dioxide evolved with several 4-h test methods was strongly correlated (r2 > 0.7) with CO2 evolved using a 48-h test. A limited-turn windrow (LTW) composting system produced compost with slightly greater stability than a passively aerated windrow (PAW) composting system. Food waste compost samples had a low CO2 evolution rate after 71 to 99 d using either composting system. Compost CO2 evolution rate at 25°C decreased with composting time, reaching approximately 1 to 4 mg CO2-C g compost C?1 d?1 for the PAW method and 0.5 to 2 mg CO2-C g compost C?1 d?1 for the LTW method. Putrescible organic matter in food waste was effectively decomposed in outdoor windrows using composting methods that did not employ forced aeration, self-propelled windrow turners, or manufactured composting vessels. Several 4-h stability tests showed promise for implementation as quality assurance tools.  相似文献   

20.
An industrial-scale composting plant has been designed for producing organic fertilizers from olive mill waste using the windrow pile system. Materials to be composted, two phase olive mill waste (TPOMW) and sheep litter (SL), were characterized and made into three piles consisting of different proportions of each. Throughout the composting process, temperature (T), moisture (M), organic matter (OM), total organic carbon (Corg), total nitrogen (NT), germination index (GI), pH and electrical conductivity (EC) were monitored. The potential agronomic value of the final composts was ascertained by analyzing the bulk density, OM and Corg concentration, pH, EC, macro and micronutrient content (N, P, K, Ca, Mg, Fe, Cu, Mn, Zn, B), the concentration of humic and fulvic acids and inorganic nitrogen (NH4+,NO2?,NO3?). Each compost was applied to an area of one hectare within a six year-old olive plantation. Four months after application, the soils showed an increased OM concentration and cationic exchange capacity (CEC).  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号