塔式自然通风好氧堆肥反应器的开发与应用

针对现有堆肥反应器处理效率低、运行和维护成本较高及堆肥效率不稳定等问题,开发了塔式自然通风好氧堆肥反应器。从物料和热量平衡、通风量优化等方面对反应器进行研究。反应器主要包括反应器主体、通风管、物料承托筛板和温度监控系统等,具有运行及维护简单、能源耗费低等优点。在通风高度为3 m,初始物料投加量5.65 kg(干重比︰粪便/锯末=1∶2.5),含水率约60%时,对人粪便进行好氧堆肥实验。结果表明,堆体温度最高至62℃,并且在50℃以上高温保持5 d;TOC和COD均呈持续下降趋势,降解率分别为64.14%和56.45%;种子发芽指数为113.64%,完全达到腐熟标准。     

接种微生物与人粪便同步连续投加对好氧堆肥效果的影响简

利用新型梨形筒式好氧堆肥反应器,在通风量为3.0 L/min,搅拌频率为5 min/h的条件下,就不接种微生物、接种土著菌种、枯草芽孢杆菌与酵母菌时人粪便连续投加好氧堆肥效果进行了对比。堆制20 d即2个运行周期中各堆体的温度、含水率、COD、总氮、pH值与GI等的变化表明,接种微生物可以显著提高堆体的升温速率与堆体平均温度、COD降解率、GI（P<0.01）,堆肥可迅速达到完全腐熟。接种土著菌种效果最为明显（P<0.01）,其后相继为枯草芽孢杆菌与酵母菌。接种土著菌种可使堆体温度在50℃以上维持18 d,第8天COD降解率达到61.17%、总氮损失率为25.75%,第6天时GI达到108.22%。     

接种微生物与人粪便同步连续投加对好氧堆肥效果的影响

利用新型梨形筒式好氧堆肥反应器,在通风量为3．0L／min,搅拌频率为5min／h的条件下,就不接种微生物、接种土著菌种、枯草芽孢杆菌与酵母菌时人粪便连续投加好氧堆肥效果进行了对比。堆制20d即2个运行周期中各堆体的温度、含水率、COD、总氮、pH值与GI等的变化表明,接种微生物可以显著提高堆体的升温速率与堆体平均温度、COD降解率、Ct（P〈0．01）,堆肥可迅速达到完全腐熟。接种土著菌种效果最为明显（P〈0．01）,其后相继为枯草芽孢杆菌与酵母菌。接种土著菌种可使堆体温度在50℃以上维持18d,第8天COD降解率达到61．17％、总氮损失率为25．75％,第6天时GI达到108．22％。     

一种新型可控堆肥反应器系统的快速厌氧堆肥研究

采用自制的好厌氧堆肥综合反应器系统进行厌氧堆肥实验。堆肥物料质量比为:污泥∶木屑∶聚丙稀酸钠(PAAS)=1∶0.15∶0.01,活性干酵母粉以50 mL/5 g的比例用5%生理盐水稀释后,按照5 g酵母粉/kg物料的比例掺入上述混合堆料中。研究表明,采用新型反应系统用于厌氧堆肥,能在21 d内完成一个堆肥周期,且堆肥过程各指标变化规律性强,堆肥效果稳定。     

投加方式和通风速率对脱水污泥堆肥效果的影响

为了在降低能耗的前提下获得更高的污泥堆肥效率和提高堆肥产品质量,利用梨形筒式好氧堆肥反应器,设置2种物料投加方式和3种通风速率,研究堆肥过程中温度、含水率、总氮以及发芽指数(GI)的变化特性。结果表明,与间歇式堆肥相比,连续式堆肥可以显著提高堆体温度和堆体腐熟度,降低堆体含水率及缩短腐熟期,但氮素损失也显著增大(P0.01);连续式堆肥的处理效率是间歇式的2.11倍,能耗降低了52.60%。通风速率为1.95 L·min~(-1)的连续式堆肥,堆体维持高温时间最长,且最终温度稳定在较高温度47~48℃,堆末含水率最低,氮素损失处于三者的中间水平,腐熟期最短。综合分析,在通风速率为1.95 L·min~(-1)的连续运行方式下,梨形筒式反应器用于污泥稳定高效堆肥是可行的。     

污泥用量对生活垃圾堆肥氮素转化与损失的影响

为了探讨生活垃圾堆肥的氮素损失问题,对生活垃圾（A组）、污泥和生活垃圾混合B组（w/w=1∶6）、C组（w/w=1∶4）组等3组物料进行高温好氧堆肥,研究污泥用量对生活垃圾堆肥化过程中温度、pH值、各氮素转化与损失的影响。结果表明：投加污泥会影响生活垃圾的通风性能,减慢物料的升温速率,延长堆肥周期。污泥用量对生活垃圾堆...     

不同添加剂下污泥堆肥化处理氮素变化研究

研究采用了高温好氧堆肥的方法,将城市生活污泥与不同比例花生壳、干污泥混合,在密闭反应器中堆肥,研究堆肥过程中氨气挥发量以及各种形态氮素含量的变化情况。结果表明,初始含水率调整在60%左右,综合堆体温度、含水率下降、氨气挥发量及氮素转化损失量,在污泥处理中添加8.3%花生壳+41.7%干污泥的处理效果最佳,其单位时间氨气挥发量为对照处理的1/5,全氮损失8.9%。在实际生产中,可以将堆肥产物干污泥循环使用,再辅以少量花生壳等干物料进行污泥堆肥,可达到降低成本的效果。     

石灰投加与搅拌对生态厕所的灭菌效果

以发展中国家农村地区的卫生条件改善为目的,开展了简易生态厕所的粪便堆肥处理实验。在投加石灰作为抑菌剂的条件下,研究了搅拌混合对杀灭致病微生物的影响,以及使堆肥终产物达到可接受风险值所需的最佳搅拌条件。实验确定了石灰的投加量,并应用Beta-Possion模型对堆肥处置过程中致病微生物对暴露人群的健康风险进行评价,从而从健康风险控制的角度确定了最佳的搅拌次数。研究结果表明,石灰投加量约占堆肥干重1.5%,手动搅拌50次,经搅拌后放置12 h能达到可接受的风险值(3.2×10-5)。     

好氧堆肥反应器对人粪便堆肥中温降解的中试研究

控制温度为（35±2）℃,以新鲜锯末为空白载体,在控制含水率为55%~60%和强制通风的好氧条件下,进行为期15 d的实验,进行了人粪便好氧堆肥的中试研究,重点分析了在堆肥过程中有机物的降解、氮素的迁移转化规律及生物量的变化。结果表明,粪便中有机物含量在前2天稍微上升,然后迅速下降,最终去除率为71.82%;随着NH₃-N释放量的增加,堆料中N_tot含量从第4天开始减少,最终损失 22.61%,其中N_org损失占74.35%,NH₃-N占23.52%;所损失的氮素有91.66%以氨氮的形式释放。粪便中的有机物和氮的含量能在8~10 d后达到稳定,且堆体无臭味;粪便中溶解性有机物为微生物的生长提供营养物质,因此生物量变化的过程与有机物降解的有着紧密的联系;病原菌在堆肥过程中得到有效去除,表明该反应器堆肥的无害化。     

粪便与生活垃圾混合堆肥过程控制

采用强制通风静态仓进行粪便和生活垃圾混合堆肥,以玉米秸为调理剂,石灰调节pH,考察正压鼓风和负压抽吸2种通风方式对不同堆料配比堆肥过程的控制效果。试验结果表明,5种堆料配比的中层温度都达到了50℃,并保持了5 d以上,达到了堆肥无害化和稳定化的要求。正压鼓风堆料底部温度较低,负压抽吸堆料底部热量容易聚集,但是后者堆体温度分布相对均匀。负压抽吸对水分的去除效果差于正压鼓风。对于温度未达到50℃的堆料应回流处理保证无害化。粪便有机物含量高,堆肥初期易酸化,添加石灰调节pH,使堆肥顺利升温,缩短发酵期,石灰合理添加量为2%(质量分数)。采用负压抽吸的通风方式,散除堆肥初期的挥发性有机酸,再经过冷凝除臭器脱酸除臭后排放,是一种可取的方式。     

生活垃圾堆肥分阶段反应动力学研究

根据堆肥不同阶段特点 ,通过接种和不接种堆肥实验 ,分别研究升温 -高温阶段和高温 -降温阶段动力学。从得到的动力学方程分析可知 :接种复合微生物菌剂 ,在升温 -高温阶段最大反应速率比对照组提高约 13 8.7 ;在高温 -降温阶段最大反应速率比对照组大 4.73 g/( h· kg) ,而半速系数 Km比对照组下降了 10 3 g/kg。说明接种复合微生物菌剂不仅使反应速率增大 ,而且使半速系数减小 ,使底物与酶反应更完全 ,有机物分解更迅速、更彻底     

Microbiological aspects of humid husk composting

The feasibility of composting as disposal practice of husk mixed with olive mill wastewaters (OMW) was studied in the present research. The process was investigated with regards to some reliable and easy to be determined microbial activity parameters such as the ATP content, the activity of a pool of enzymes and the viable counts, keeping in mind the well known bias of this last technique. Two different composting technologies were compared: static pile and reactor by studying the cured composts obtained. Among the bioindicators tested, the composting process trend was described better by the ATP content and the activity of some enzymes. In fact, the ATP content showed an increase during the thermophilic phase in both the pile and the reactor, and decreased at the end of the process, it was also higher in the bioreactor-pile technology than in the pile. With regard to the enzymatic activity, with the reactor technology experiment, two peaks were evidenced in the thermophilic phase and during the curing phase in pile, and a drop during the transfer of material from the reactor to the pile. The quality of the cured product obtained using the reactor technology has been evaluated considering phytoxicity and hygienic features: the stabilised compost resulted to have neither phytoxical effect, nor faecal indicator contaminants.     

不同堆肥方式对鸡粪与秸秆混合堆肥效果

以鸡粪和玉米秸秆为堆肥原材料,进行了露天堆肥和反应器堆肥对比实验。结果表明,反应器堆肥（堆体P2）较露天堆肥（堆体P1）升温快,堆体P2达到了《粪便无害化卫生标准（GB7959—87）》的要求,堆体P1未达到;在整个堆肥过程中,堆体P1的水分总损失量（26．5％）大于堆体P2的水分总损失量（20．6％）;堆体P1和P2的有机质降解主要发生在堆肥前期0～21d,分别完成了81．4％和84．5％的有机质降解量;堆体P1和P2的C／N比在堆肥过程中均呈下降趋势,最终C／N比分别为18．3和14．8;种子发芽指数GI_P1〈GI_P2,表明采用堆体P2的堆肥产品的植物毒性较堆体P1更小。各指标实测数据表明,反应器堆肥的堆肥产品的稳定性和腐熟程度较露天堆肥更好。     

广州市生活垃圾高温有氧静态堆肥的生命周期分析

运用生命周期分析(LCA)方法,对广州市生活垃圾高温有氧静态堆肥系统进行分析,计算出全生命周期的资源消耗和环境影响潜值,同时与垃圾焚烧典型工艺的LCA数据进行对比。结果表明,堆肥处理的环境影响负荷为0.023PET90,资源消耗系数为9.238mPET90。环境影响类型中光化学臭氧合成造成的影响最大,占环境总影响的43.8%。与焚烧处理方式相比,高温有氧静态堆肥的环境总影响较小,环境影响负荷相比于焚烧减少20.3%,在降低酸化的影响方面有较为显著的作用。     

牛粪与小麦秸秆混合高温堆肥的腐熟进程研究

通过研究牛粪与小麦秸秆混合高温堆肥的腐熟进程,寻求最佳的堆肥体积比,旨在为农业废弃物快速资源化利用提供科学依据。将牛粪与小麦秸秆分别按体积比10∶0、8∶2、6∶4、4∶6、2∶8混合,高温堆肥64d,研究各种处理下堆肥进程。结果表明,与纯牛粪高温堆肥相比,添加小麦秸秆可以加快堆肥升温速度,抑制高温堆肥前期pH的升高和氨气挥发,减少氮素损失,加速堆肥内有毒有害物质分解,加快C/N降低速率。其中牛粪和小麦秸秆以6∶4的体积比混合高温堆肥时效果最好,堆肥结束时有机质和速效氮下降幅度最小,分别为31.84%和18.18%,全氮、全磷、全钾、速效磷和速效钾的提高幅度最大,分别为15.86%、13.64%、9.42%、22.73%和29.30%。若以种子发芽指数80%作为堆肥腐熟的评价指标,牛粪和小麦秸秆按6∶4体积比混合高温堆肥43d即可腐熟,比纯牛粪腐熟提前了12d。综合判断,实际应用中牛粪与小麦秸秆按6∶4体积比进行高温堆肥较为适宜。     

ESTROM—a Romanian–Swiss research programme

Background, aim, and scope  Composting is an effective treatment process to realize sludge land application. However, nitrogen loss could result in the reduction of nutrient value of the compost products and the stabilization effect of composting on heavy metal concentration and mobility in sludge has been shown to be very limited. Materials and methods  Laboratory-scale experiments were carried out to investigate the effects of bamboo charcoal (BC) on nitrogen conservation and mobility of Cu and Zn during sludge composting. Results  The result indicated that the incorporation of BC into the sludge composting material could significantly reduce nitrogen loss. With 9% BC amendment, total nitrogen loss at the end of composting decreased 64.1% compared with no BC amendment (control treatment). Mobility of Cu and Zn in the sludge may also have been lessened, based on the decline in diethylenetriaminepentaacetic acid-extractable Cu and Zn contents of composted sludge by 44.4% and 19.3%, respectively, compared to metal extractability in the original material. Discussion  Ammonia adsorption capability of BC might be the main reason for the retention of nitrogen in sludge composting materials. Decrease of extractable Cu²⁺ and Zn²⁺ in the composting material mainly resulted from the adsorption of both metals by BC. Conclusions  Incorporation of BC into composting material could significantly lessen the total nitrogen loss during sludge composting. Mobility of heavy metals in the sludge composting material could also be reduced by the addition of BC. Recommendations and perspectives  Bamboo charcoal could be an effective amendment for nitrogen conservation and heavy metal stabilization in sludge composts. Further research into the effect of BC-amended sludge compost material on soil properties, bioavailability of heavy metals, and nutrient turnover in soil needs to be carried out prior to the application of BC-sludge compost in agriculture.     

Bioremediation of oil-contaminated soil using Candida catenulata and food waste

Even though petroleum-degrading microorganisms are widely distributed in soil and water, they may not be present in sufficient numbers to achieve contaminant remediation. In such cases, it may be useful to inoculate the polluted area with highly effective petroleum-degrading microbial strains to augment the exiting ones. In order to identify a microbial strain for bioaugmentation of oil-contaminated soil, we isolated a microbial strain with high emulsification and petroleum hydrocarbon degradation efficiency of diesel fuel in culture. The efficacy of the isolated microbial strain, identified as Candida catenulata CM1, was further evaluated during composting of a mixture containing 23% food waste and 77% diesel-contaminated soil including 2% (w/w) diesel. After 13 days of composting, 84% of the initial petroleum hydrocarbon was degraded in composting mixes containing a powdered form of CM1 (CM1-solid), compared with 48% of removal ratio in control reactor without inoculum. This finding suggests that CM1 is a viable microbial strain for bioremediation of oil-contaminated soil with food waste through composting processes.     

Influence of aeration rate and reactor shape on the composting of poultry manure and sawdust

To achieve successful composting, all the biological, chemical, and physical characteristics need to be considered. The investigation of our study was based on various physicochemical properties, i.e., temperature, ammonia concentration, carbon dioxide concentration, pH, electrical conductivity (EC), carbon/nitrogen (C/N) ratio, organic matter (OM) content, moisture content, bacterial population, and seed germination index (GI), during the composting of poultry manure and sawdust for different aeration rates and reactor shapes. Three cylindrical-shaped and three rectangular-shaped pilot-scale 60-L composting reactors were used in this study, with aeration rates of 0.3 (low), 0.6 (medium), and 0.9 (high) L min^?1 kg^?1 DM (dry matter). All parameters were monitored over 21 days of composting. Results showed that the low aeration rate (0.3 L min^?1 kg^?1 DM) corresponded to a higher and longer thermophilic phase than did the high aeration rate (0.9 L min^?1 kg^?1 DM). Ammonia and carbon dioxide volatilization were directly related to the temperature profile of the substrate, with significant differences between the low and high aeration rates during weeks 2 and 3 of composting but no significant difference observed during week 1. At the end of our study, the final values of pH, EC, moisture content, C/N ratio, and organic matter in all compost reactors were lower than those at the start. The growth rates of mesophilic and thermophilic bacteria were directly correlated with mesophilic and thermophilic conditions of the compost. The final GI of the cylindrical reactor with an airflow rate of 0.3 L min^?1 kg^?1 DM was 82.3%, whereas the GIs of the other compost reactors were below 80%. In this study, compost of a cylindrical reactor with a low aeration rate (0.3 L min^?1 kg^?1 DM) was more stable and mature than the other reactors.

Implications: The poultry industry is growing in South Korea, but there are problems associated with the management of poultry manure, and composting is one solution that could be valuable for crops and forage if managed properly. For high-quality composting, the aeration rate in different reactor shapes must be considered. The objective of this study was to investigate various physicochemical properties with different aeration rates and rector shapes. Results showed that aeration rate of 0.3 L min^?1 kg^?1 DM in a cylindrical reactor provides better condition for maturation of compost.