蚯蚓堆肥过程对污泥重金属化学行为的影响

蚯蚓堆肥过程会对重金属迁移转化进行调整,从而改变重金属在污泥中的形态。对蚯蚓堆肥过程中污泥中重金属浓度、形态的变化趋势进行归纳,提出了蚯蚓堆肥过程中影响重金属行为的因子,对调理剂作用于蚯蚓堆肥污泥中重金属的效果进行了说明,同时,对蚯蚓堆肥后污泥的应用进行了探讨。     

园林废弃物与污泥协同堆肥的绿化应用

通过在园林废弃物堆肥中添加不同比例污泥进行混合堆肥实验,研究堆肥过程中温度、pH值等指标变化情况,探究堆肥产物应用于绿化行业的可行性。研究发现:园林废弃物堆肥中添加一定量的污泥,能优化堆肥环境,堆肥效果较好;比例适宜的混合堆肥表现出升温速度、高温期时间、腐熟效率、安全性等方面具有一定优势;目前我国园林废弃物资源化比例较低,混合堆肥产物可作为土壤改良基质进行土地利用,实现资源化利用,促进园林绿化产业发展。     

不同菌剂处理下猪粪和牛粪堆肥前期性质变化

以猪粪和牛粪为堆肥原料,设计了人工接种MixF-3菌剂堆肥、添加灭活菌剂堆肥和自然堆肥3个处理进行堆肥前期实验,探讨堆肥9d过程中温度、水分、有机碳、全氮和微生物量碳等参数的变化。结果表明,按1L/t接种MixF-3混合菌剂堆肥温度升温快,猪粪堆肥第48h和第84h时温度分别达到66℃和71.5℃,牛粪堆肥第48h时温度达69℃,明显高于灭活菌剂处理组和CK对照组。随着堆肥的进行,各处理组水分含量缓慢下降,牛粪比猪粪含水量略高。人工接种菌剂的猪粪和牛粪堆肥处理组中pH变化幅度小,有机碳碳含量的下降幅度比灭活组和自然堆肥组大,分别下降15.64%和11.25%,全氮含量缓慢升高但变化不大,人工接种牛粪比猪粪处理组中堆肥全氮含量升幅高;在猪粪和牛粪堆肥中人工接种菌剂微生物量碳降幅最小,分别为9537μg/g和3212μg/g,表明在猪粪和牛粪堆肥原料中添加MixF-3复合菌剂有利于微生物繁殖生长,同时拓宽了菌剂使用的单一性,更具有普遍性意义。     

堆肥中腐熟污泥替代外源添加剂的研究

本文对用腐熟污泥替代木屑等外源添加剂高温好氧堆肥作了研究。通过腐熟污泥回流三次的堆肥结果显示,每次回流的堆肥温度都能在55℃以上保持5天以上,达到无害化的要求,含水率都能降到45％左右,污泥的有机物降解率相近,pH在6～9之间。需要注意的是腐熟污泥多次回流中重金属浓度有个增加的过程,达到峰值后逐渐下降。     

膜覆盖污泥堆肥技术在我国北方冬季的实验研究

膜覆盖污泥堆肥技术是功能性薄膜防水、透气性能对静态堆肥的改良,保留了静态堆肥的优势又避免了其技术的不足。通过膜覆盖系统在我国北方冬季污泥好氧发酵过程中的污泥指标变化,探究在北方的冬季,污泥通过膜覆盖技术进行好氧发酵的适用性。     

多阶段生活垃圾接种堆肥水溶性有机物荧光特性表征研究

为提高堆肥效率,采取多阶段接种技术（MSIC）进行城市生活垃圾堆肥实验,并运用荧光分析技术,对不同堆肥阶段样品提取出的水溶性有机物（DOM）的变化进行跟踪分析。荧光同步光谱分析显示：堆肥过程中类蛋白峰发生红移,且在堆肥后期出现了类腐殖质峰,且类腐殖质荧光峰与类蛋白荧光峰荧光强度的比值‰‰不断增大,T2处理增长幅度最大。发射光谱分析显示：254nm激发波长下发射光谱中后1／4波段与前1／4波段的荧光强度积分面积之比A435-450/A300-345、465nm激发波长下发射光谱中470～640nm范围内荧光积分面积A协枷均不断增大,表明堆肥腐殖化程度不断增强,且T2处理在堆肥各阶段腐殖化程度均高于其他处理,T2处理物质结构最为复杂,腐殖化程度达到最高。三维荧光光谱显示：随着堆肥的进行,与蛋白质类物质有关的类蛋白峰荧光强度持续降低,而与腐殖质类物质产生的类富里酸荧光峰强度却不断增强;紫外区与可见区类富里酸峰荧光强度的比值r（A,C）随着堆肥的进行总体呈下降趋势;T2处理DOM中有机成分发生最为显著的变化,各阶段类蛋白荧光峰的发射波长明显发生红移,并且紫外、可见区域内类富里酸荧光强度明显高于其他处理,促进堆肥DOM中类富里酸物质数量的积累。结果表明：MSIC能够有效促进堆肥腐殖化进程,提高堆肥效率,是一种更加优良的堆肥技术。     

高温堆肥发酵工艺处理城市生活垃圾过程中的部份微生物学问题

本文描述了高温堆肥发酵工艺处理城市生活垃圾过程中的微生物生态学过程。多种微生物分别在不同阶段参与了垃圾堆肥的发酵腐熟过程。论述了垃圾发酵期间 ,人工接种功能微生物菌剂可以加速堆肥材料的发酵腐熟作用 ,缩短发酵周期 ,节省城市生活垃圾处理的运行成本。     

SACT污泥全机械化堆肥工艺与自动控制系统

阐述了SACT-BII污泥堆肥工艺以及自动控制系统组成,介绍了混料控制系统、发酵仓控制系统、物料输送控制系统等三个子系统,分析了工艺目的和过程控制。结论为:机械化堆肥实现的关键在于自动控制系统的设计,成败取决于自动控制系统的可靠性。运行良好的自动控制系统可以为污泥机械化堆肥项目大型化提供技术支撑。     

不同腐熟度猪粪、奶牛粪在小白菜和香瓜上施用的农学效应研究

进行猪粪和奶牛粪自然高温堆肥发酵,分别在15、25、35、50 d取样,获得了不同腐熟程度堆肥产物,分别进行了小白菜和香瓜种子发芽与田间应用试验,以期获得不同腐熟堆肥在蔬菜上施用的农学效应,旨在从堆肥农田施用的农学效应角度,为制订堆肥腐熟度标准提供科学依据。结果表明：牛粪堆肥过程中的最高温度高于猪粪,且高温期也长于猪粪;两种处理在35d有机碳含量均显著降低,全氮含量为先降低后升高趋势;两种堆肥在35d后,均达到无害化标准。不同腐熟程度堆肥对小白菜株高和主根长及香瓜苗重和主根长均没有明显抑制作用,对小白菜和香瓜出苗率、根系活力及小白菜单株鲜重和生物产量影响较大,尤其是猪粪腐熟25d,奶牛粪腐熟15d的堆肥表现出显著抑制作用。将堆肥理化参数与小白菜、香瓜生长指标进行相关分析表明：pH值、全氮含量和C/N这3种指标均与小白菜和香瓜各项生物性状无显著相关性;有机碳和DOC与各项生物性状指标均表现出显著或极显著相关性;铵/硝与小白菜和香瓜的GI和根系活力均表现极显著或显著的相关性,其结果与现行的堆肥腐熟度指标并不一致。因此,在制订堆肥腐熟度标准时,应关注堆肥产物农田施用后不同作物所表现出的不同农学效应。     

高温堆肥发酵工艺处理城市生活垃圾处理城市生活垃圾过程中的部分微生物学

本文描述了高温堆肥发酵工艺处理城市生活垃圾过程中的微生物生态学过程。多种微生物分别在不同阶段参与了垃圾堆肥的发酵腐熟过程。论述了垃圾发酵期间,人工接种功能微生物菌剂可以加速堆肥材料的发酵腐熟作用,缩短发酵周期,节省城市生活垃圾处理的运行成本。     

浅谈污水厂污泥堆肥化技术

堆肥化技术是使污水厂污泥达到稳定化和无害化的一种经济而有效的手段。目前常用的污泥堆肥化系统可以划分为:条垛系统,强制通风静态垛系统和发酵槽系统。为了加快微生物对污泥中有机物的降解转化,提高处理能力,可对以下因素进行控制:C/N比,含水率,空隙率,温度和通风。在判定污泥堆肥腐熟上,建议采用与氮有关的参数如氨氮、亚硝酸和硝酸盐氮等作为污泥堆肥一般性熟化判定指标。     

Evaluation of municipal solid waste composting kinetics

Most modern municipal solid waste (MSW) composting operations have emphasized the enhancement of decomposition of the organic fraction of the waste to comply with strict environmental regulations. This can be achieved once the composting process kinetics are well understood. This study examined process kinetics through experimentation with bench-scale reactors under controlled composting conditions to show the interdependence between biological, chemical and physical factors during composting of MSW. The effects of temperature, moisture content, waste particle size and carbon to nitrogen (C/N) ratio on process kinetics were evaluated. The results obtained revealed that these factors should be carefully controlled in order to achieve optimum process performance. It has been found that the organic matter degradation during composting follows a first-order kinetic model.     

Composting and compost application in China

The current situation of municipal solid waste (MSW) and sewage sludge production (in terms of volume as well as composition) in China is introduced. Composting and compost application in China are reviewed. In China, the production of municipal solid waste and sewage sludge is changing rapidly along with economic development. Composting is mainly applied for treating MSW, about 20% of the total amount of MSW being disposed. MSW composting is mainly co-composted with night soil or sewage sludge. Compost is used in agriculture, forestry and horticulture. Compost application is the key factor influencing the composting development in China. To promote composting and compost application in China, a state-wide survey on the production, composition and physical and chemical properties of MSW and sewage sludge should be carried out. More effort should be made to develop low cost and high efficient composting technologies according to China's conditions. The environmental impact of compost application should also be given more attention.     

Degradation of greenhouse twines derived from natural fibers and biodegradable polymer during composting

Commercial composting operations generally do not accept organic wastes with plastic twines from the greenhouse vegetable industry and the bulk of the waste materials ends up in landfills. The objectives of this paper are to identify environmentally compatible substitutes that could replace the current use of petrochemically derived plastic twines in greenhouse vegetable production, thus diverting them from landfills, and to assess the extent of their degradation via composting. Physical properties of the twines, including linear density, percent weight loss and tensile strength were monitored for the biodegradation tests. A pilot-scale composting trial was conducted in an in-vessel composting system. Results showed that the three biodegradable twine materials (cotton, jute and EcoPLA) could degrade readily in a composting environment within a reasonable time frame. Specifically, at the end of 105 days of composting, 85.3%, 84.8% and 81.1% of weight loss was observed for cotton, jute and EcoPLA, respectively. Furthermore, EcoPLA exhibited a slower decline in tensile strength with time, when compared to jute and cotton.     

Greenhouse gas balance for composting operations

The greenhouse gas (GHG) impact of composting a range of potential feedstocks was evaluated through a review of the existing literature with a focus on methane (CH(4)) avoidance by composting and GHG emissions during composting. The primary carbon credits associated with composting are through CH(4) avoidance when feedstocks are composted instead of landfilled (municipal solid waste and biosolids) or lagooned (animal manures). Methane generation potential is given based on total volatile solids, expected volatile solids destruction, and CH(4) generation from lab and field incubations. For example, a facility that composts an equal mixture of manure, newsprint, and food waste could conserve the equivalent of 3.1 Mg CO(2) per 1 dry Mg of feedstocks composted if feedstocks were diverted from anaerobic storage lagoons and landfills with no gas collection mechanisms. The composting process is a source of GHG emissions from the use of electricity and fossil fuels and through GHG emissions during composting. Greenhouse gas emissions during composting are highest for high-nitrogen materials with high moisture contents. These debits are minimal in comparison to avoidance credits and can be further minimized through the use of higher carbon:nitrogen feedstock mixtures and lower-moisture-content mixtures. Compost end use has the potential to generate carbon credits through avoidance and sequestration of carbon; however, these are highly project specific and need to be quantified on an individual project basis.     

城市污泥堆制腐熟度的评价方法比较

本文介绍了城市污泥在堆制处置时的腐熟度评价的多种方法,这些方法分别从化学、生物学等不同的角度给出了如何评价城市污泥堆制的腐熟度。结合对这些方法的比较,提出了一些建设性的看法和意见。     

Convenience improves composting and recycling rates in high-density residential buildings

Increasing volumes of solid waste, implicated in environmental pollution and health problems, are central to the current environmental crisis. In two randomized field experiments, we demonstrate that convenience dramatically boosts recycling and composting rates in multi-family dwellings and university residences. When compost bins were placed on each floor in a multi-family residence, instead of on the ground floor, composting rates increased by 70%, diverting 27 kilograms of compost from the landfill per unit per year. When recycling stations were placed just meters from suites in student residences, instead of in the basement, recycling increased by 147% (container), and 137% (paper), and composting increased by 139%, diverting 23, 22, and 14 kilograms of containers, paper, and compost, respectively, from the landfill per person per year. Simply making recycling and composting convenient can significantly increase waste diversion, and as such this single intervention has important implications for waste management and environmental policy.     

Environmental assessment of two home composts with high and low gaseous emissions of the composting process

A Life Cycle Assessment (LCA) of two home composts with low and high gaseous emissions of the composting process is presented. The study focused on the gaseous emissions of the composting process. Gaseous emissions of methane, nitrous oxides, ammonia and volatic organic compounds of the composting process were experimentally measured in field real trials. The results showed that the differences in gaseous emissions between the two home composts were 4.5, 5.8 and 52 for methane, nitrous oxides and ammonia, respectively. Higher emissions of nitrous oxides and methane affected significantly the category of global warming potential, while higher emissions of ammonia affected mainly the categories of acidification potential, eutrophication potential and photochemical oxidation. The differences found in the compost emissions were attributable to the composting production management (quality and composition of waste stream, frequency mixing of waste, humidity and temperature monitoring, among others) as well as weather conditions (temperature and humidity).     

Degradation of biomacromolecules during high-rate composting of wheat straw-amended feces

Pig (Sus scrofa) feces, separately collected and amended with wheat straw, was composted in a tunnel reactor connected with a cooler. The composting process was monitored for 4 wk and the degradation of organic matter was studied by two chemical extraction methods, 13C cross polarization magic angle spinning (CPMAS) nuclear magnetic resonance (NMR) and pyrolysis gas chromatography-mass spectrometry (GC-MS). Wet-chemical extraction methods were not adequate to study the degradation of specific organic compounds as the extraction reagents did not give selective separation of hemicellulose, cellulose, proteins, and lignins. A new method was proposed to calculate the contribution of four biomacromolecules (aliphatics, proteins, polysaccharides, and lignin) from the 13C CPMAS NMR spectrum. Pyrolysis GC-MS allowed identification of the composition of the biomacromolecules. The biomacromolecules showed different rates of degradation during composting. High initial degradation rates of aliphatics, hemicellulose, and proteins were observed, where aliphatics were completely degraded and hemicellulose and proteins were partly recalcitrant during the four weeks of composting. The degradation rate of cellulose was much lower and degradation was not completed within the four weeks of composting. Lignin was not degraded during the thermophilic stage of composting but started to degrade slowly during the mesophilic stage. A combination of 13C CPMAS NMR and pyrolysis GC-MS gave good qualitative and semiquantitative assessments of the degradation of biomacromolecules during composting.     

Effect of chemical and microbial amendments on ammonia volatilization from composting poultry litter

Research has shown that aluminum sulfate (alum) and phosphoric acid greatly reduce ammonia (NH3) volatilization from poultry litter; however, no studies have yet reported the effects of these amendments on field-scale composting of poultry litter. The objectives of this study were to (i) evaluate NH3 volatilization from composting litter by measuring both NH3 volatilization and changes in total nitrogen (N) in the litter and (ii) evaluate potential methods of reducing NH3 losses from composting poultry litter. Poultry litter was composted for 68 d the first year and 92 d the second year. Eleven treatments were screened in Year 1, which included an unamended control, a microbial mixture, a microbial mixture with 5% alum incorporated into the litter, 5 and 10% alum rates either surface-applied or incorporated, and 1 and 2% phosphoric acid rates either surface-applied or incorporated. Treatments in Year 2 included an unamended control, a microbial mixture, alum (7% by fresh wt.), and phosphoric acid (1.5% by fresh wt.). Alum and phosphoric acid reduced NH3 volatilization from composting poultry litter by as much as 76 and 54%, respectively. The highest NH3 emission rates were from microbial treatments each year. Compost treated with chemical amendments retained more initial N than all other treatments. Due to the cost and N loss associated with composting poultry litter, composting is not economical from an agronomic perspective compared with the use of fresh poultry litter.