C/N对蓝藻好氧堆肥腐熟及无害化进程的影响

为探索和优化脱水蓝藻藻泥好氧堆肥无害化处理工艺参数,利用堆肥反应器,研究了C/N分别为5（T1）、15（T2）和25（T3）的处理对蓝藻藻泥腐熟进程及微囊藻毒素（MC）降解速率的影响。结果表明,堆肥过程中各处理间的pH、总碳量及其形态、总氮量及其形态、总磷含量、总钾含量、种子发芽指数差异显著。与蓝藻自然堆置相比,添加辅料增加堆体C/N可提高蓝藻的腐熟速度。堆肥35d后,T2和T3处理的堆肥成品均已满足有机肥行业标准,种子发芽指数均高于80%;但MC-LR和MC-RR仍有较大的降解潜力,从无害化的角度考虑,蓝藻高温堆肥时间不应少于50d。C/N过高增加了氮素的损失,如何进一步降低氮素的损失,提高堆肥过程中MC的降解将是今后蓝藻堆肥研究的重点。     

含水率对羊粪堆肥腐熟度及污染气体排放的影响

为了优化羊粪好氧堆肥的工艺条件,研究初始含水率对羊粪堆肥腐熟度及污染气体排放的影响。本文以高湿新鲜羊粪为堆肥原料（含水率为75%）,添加玉米秸秆调节初始物料含水率分别为70%、65%、60%和55%,堆肥在60 L密闭发酵罐中共持续35 d。结果表明：75%含水率羊粪堆体单独不能顺利启动升温,且在试验期间释放了大量的甲烷和氧化亚氮等温室气体,在所有处理中产生的总温室效应最大（41.4 g/kg）。玉米秸秆与羊粪联合均能成功启动堆肥过程,且堆肥产品均可以达到无害化卫生要求和腐熟标准。其中初始含水率为65%时,堆体不仅高温期持续时间长,且有机质降解程度高,物料干质量降解率达45%,同时比其他处理可降低4.81%～16.99%的总氮损失和7.56%～48.62%的总温室气体排放量。因此,在羊粪和玉米秸秆联合堆肥时,初始含水率65%左右为最佳条件。     

不同热解温度生物质炭对羊粪堆肥过程氮素损失的减控效果

为探讨高温堆肥中氮素损失的有效控制技术，以2种不同热解温度制备的稻壳生物质炭为堆肥添加剂，与羊粪、食用菌渣混合，进行了43 d的堆肥试验。设置了3 个处理，羊粪与食用菌渣质量比9:1混合体作为预备物料，在预备物料上分别添加450、650 ℃热解的生物质炭（占预备物料质量百分比15%）为B1、B2处理，在预备物料上添加未热解的稻壳（与生物质炭等体积）为CK处理。监测了堆肥体的温度、NH3挥发、N2O排放、pH值等参数变化动态，分析了不同热解温度生物质炭在堆肥中的保氮效果。结果表明，B1、B2处理促进了堆肥初期的温度快速上升，堆肥体初次升温至55 ℃所需时间分别较CK 缩短了2、6 d，B2 处理的促升温、增温效应优于B1 处理；堆肥43 d 后，CK、B1 与B2处理的NH3挥发累积量分别为378.12、117.22、94.16 mg/kg，N2O排放累积量分别为13.9、26.3、23.6 mg/kg，氮素损失率分别为47.8%、34.1%，30.5%；B1、B2处理增加了堆肥体N2O排放，降低了堆肥体NH3挥发，整个堆肥过程中N2O排放累积量远小于NH3挥发累积量，添加生物质炭对堆肥过程氮素损失表现为正向的减控作用，B1、B2处理的氮素损失率分别较CK处理降低了28.6%、36.19%，B1、B2处理之间差异不显著（P＞0.05）。综合堆温快速上升、氮素损失控制等指标，B2处理对羊粪堆肥过程保氮效果优于B1处理；堆肥工程中应用生物质炭减控氮素损失及提高堆肥质量，优选热解温度650 ℃制备的生物质炭。     

基于EDEM的分仓立式好氧堆肥反应器设计与试验

针对好氧堆肥周期长、腐熟均一化程度低以及反应器利用效率低等问题,该研究设计了一种单层发酵室有效容积为120 L、3层相互独立的好氧堆肥反应器,可对堆肥过程的各阶段进行控制且缩短堆肥周期,实现连续进出料堆肥。利用ANSYS对搅拌系统校核分析,搅拌轴的最大应力为75.288MPa,最大变形为3.680mm,强度符合设计要求;应用EDEM和Fluent仿真分析,结果表明：搅拌轴转速为20 r/min时,反应器下料率为98.14%,反应器曝气时混合物料的气体体积分数均在90%以上,下料及曝气效果良好。采用鸡粪与玉米秸秆1:4（干质量比）混合原料进行堆肥试验,结果表明：对于连续投放的3个批次物料,同一层物料温度差异不显著（P>0.05）,且高温期温度高于50℃的时间分别为9、7和5 d,达到无害化要求;3个批次物料的pH值均在8.0～9.0之间,电导率均在2.0～3.0m S/cm之间,各层之间差异显著（P<0.05）,各批次物料间差异不显著（P>0.05）。堆肥结束后,种子发芽率均大于100%,挥发性固体降解率分别为14.99%、16.03%和13.24%,各批次堆肥产品性质...     

易降解有机质含量对黄瓜秧堆肥腐熟和氮损失的影响

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。     

城市污泥与调理剂混合堆肥过程中有机质组分的变化

【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。     

脲酶抑制剂NBPT对鸡粪好氧堆肥的保氮效果

利用堆肥反应器, 以鸡粪和蘑菇渣为原料进行好氧堆肥, 在堆肥中添加不同浓度的脲酶抑制剂NBPT, 研究其对堆肥氮素转化的影响及保氮效果。结果表明: 添加不同浓度的脲酶抑制剂NBPT对堆肥进程中温度无显著影响, 在堆肥的高温阶段可有效控制堆料pH的升高, 在堆肥高温前期的0~10 d可有效降低堆肥的脲酶活性, 在堆肥中后期10~25 d明显提高全氮含量。堆肥25 d后, 添加0.04 mL·kg^-1、0.08 mL·kg^-1、0.16 mL·kg^-1脲酶抑制剂NBPT分别比CK减少氮素损失6.61%、4.89%和13.51%。堆肥过程中, 堆料铵态氮含量呈升-降-升-降的双峰趋势, 且大部分时间CK处理的铵态氮含量高于添加脲酶抑制剂NBPT处理, 且CK处理铵态氮的两次升高速度均高于添加脲酶抑制剂NBPT处理。在堆肥的升温和高温期硝态氮含量不稳定, 但堆肥结束时, 各添加脲酶抑制剂NBPT处理的硝态氮含量显著高于CK处理。本试验结果表明, 在堆肥过程中添加脲酶抑制剂NBPT可延缓鸡粪中的尿素态氮向铵态氮的转化, 增加堆肥成品中的硝态氮含量。在畜禽粪好氧堆肥中加入脲酶抑制NBPT可起到一定的保氮作用。     

过磷酸钙用量对猪粪堆肥过程及磷形态变化的影响

【目的】过磷酸钙作为常用的畜禽粪便堆肥添加剂,具有减少氮素损失率并提高氮、磷养分含量等优点,但其对磷的有效性和形态的影响有待深入探讨。通过试验研究不同过磷酸钙添加量对猪粪锯末好氧堆肥过程的影响及堆肥中不同形态磷含量和形态之间的相互转化规律,以期为畜禽粪便堆肥中磷素的转化及合理施用提供科学依据。【方法】将猪粪和锯末以质量比（鲜重）4:1的比例混合,然后按照猪粪和锯末干物质量的5%、10%、15%添加过磷酸钙,以不添加过磷酸钙作为对照（CK）,进行42 d好氧堆肥,监测堆肥温度、含水率、pH、全氮、有机碳、全磷、有效磷、有机磷等指标。【结果】与CK相比,添加适量过磷酸钙可以显著提高堆肥的温度,增加高温持续期2~10 d;提高堆肥物料的持水能力,加快有机碳降解。添加5%~15%的过磷酸钙可以显著降低堆肥初始pH值0.33~0.68个单位,有效抑制堆肥过程中铵态氮的挥发损失,CK、5%、10%和15%的处理在堆肥结束时的氮素损失率分别为29.4%、26.6%、18.5%和8.0%,全氮和全磷含量分别较堆肥初增加17.3~34.2%和37.0%~123.1%。CK有效磷含量随堆肥时间不断上升,第42 d较堆肥初增加73.0%,而添加过磷酸钙5%、10%和15%的处理有效磷含量显著降低,分别较堆肥初减少了4.0%、23.2%和41.8%。随着堆肥的进行,各处理中有效磷占全磷的比例均不断下降,表明堆肥过程降低了磷的有效性。堆肥前期以有机磷的矿化为主,后期以有机磷的合成为主,第42 d有机磷占全磷的比例CK最高（22.1%）,添加5%、10%和15%过磷酸钙的处理分别为15.4%、11.0%和8.7%。【结论】猪粪堆肥中添加过磷酸钙,可以有效减少氮素损失,加快有机物料降解,以10%的添加量效果最佳;堆肥过程降低了磷的有效性,随着过磷酸钙用量的增加有效磷的比例不断下降;腐熟后堆肥中的磷以无机态为主,有机磷占全磷的比例随着过磷酸钙用量的增加而递减。     

木本泥炭添加比例对猪粪堆肥腐熟度和污染及温室气体排放的影响

针对当前猪粪好氧堆肥过程中存在的腐熟度低、氮素损失严重、污染气体排放量大等问题,该研究以木本泥炭作为添加剂与猪粪进行联合堆肥,研究了不同木本泥炭添加量(添加比例依次为占物料湿基质量的5%、10%、15%和20%的4个处理)对猪粪好氧堆肥产品腐熟度和堆肥过程中CH4、NH3和H2S等污染气体排放变化的影响。结果表明:在猪粪堆肥中添加木本泥炭作为调理材料,堆体可成功启动升温,在第2~4天堆体可进入高温期,并持续7 d以上,达到无害化卫生标准;经28 d好氧堆肥以后,堆肥产品p H值为8.0左右,电导率值为1.47~1.82 m S/cm,发芽指数均大于80%,达到腐熟标准;木本泥炭添加量增加至15%以上时,有机质分解程度高,物料干质量降解率达22%左右,28 d堆体含水率下降35%左右,CH4、NH3和H2S排放量分别减少82.12%~89.48%、53.47%~63.31%、50.98%~62.76%,总温室气体排放当量减少70.34%~83.26%,堆体总氮损失减少率达44%~63%,保氮效果显著。因此,建议木本泥炭用作猪粪堆肥添加剂的最优添加量为15%~20%(以物料总湿重计)。     

粪便好氧堆肥过程中温度对有机物的降解和氮的保持特性影响

研究堆肥过程温度对有机物的降解,尤其是氮的迁移转化的影响,对于提高堆肥效率和保持更多的氮在产物中具有重要意义。本研究采用密闭式好氧堆肥反应器,模拟高温(60℃)和中温(35℃)两种典型的堆肥温度,以新鲜锯末为空白载体,在含水率60%以及连续强制供气的条件下,进行了为期两周的试验,评估温度对于粪便中有机物的降解和氮的迁移转化的影响。结果表明,粪便中有机物(固体中的有机物,总有机碳、化学需氧量)高温去除率70%,比中温的63%高出11%;且堆肥腐熟期高温(6～8 d)比中温(10～11 d)缩短约4 d。总氮的损失高温(17%)比中温(31.4%)减少了约50%。高温下氮的损失发生在堆肥反应的第1 d,由无机氮的迅速减少造成,有机氮几乎未变。中温下氮的损失在堆肥反应的前4 d,由无机氮和有机氮共同参与。研究表明,温度对堆肥具有显著的影响,控制合适的堆肥温度不仅可以加快有机物的腐熟,提高效率,还可以减少氮的损失,提高产物的肥效。     

Intermittent Aeration for In-vessel Composting Of Crab Processing Waste

A crab processing waste/wood shaving mixture was composted in-vessel with four intermittent aeration strategies. The composting process was monitored to assess the efficacy of the aeration methods. Temperature, moisture content and volatile solids of the compost were monitored along with the interstitial oxygen concentration. There was no significant difference in temperature profiles between constant frequency aeration and temperature feedback controlled aeration methods. An increased frequency of aeration resulted in significantly more drying than the less frequent aeration using the same total air volume. Results indicated that air volume could be reduced after the first five days of composting, and the in-vessel composting retention time could be reduced to 15 to 17 days for odor and vermin/vector problems prevention.     

Control of Composting Odor Using Biofiltration

While composting transforms manure wastes into useful fertilizer, it also produces odors during the decomposition process. Biofiltration is a desirable method to control composting odor. This study was conducted to investigate the efficiency of using compost as a biofilter. A mixture of cattle manure and fresh compost was composted in a bin equipped with a suction-type blower. The exhaust gas was filtered through the biofilter of fresh compost. The composting temperature affected the ammonia emission. When the composting temperature was relatively high, the highest ammonia emission appeared in two experiments. The biofiltering properties were investigated according to flow rates and filter depths for two different types of fresh composts (experiment I and II). At the flow rate of 30 L/min, ammonia removal rate was 80.5% for biofilter A(detention time 56.5 s) and 99.9% for biofilter B (detention time 113 s). At the flow rate of 50 L/min, the ammonia removal rate was 82.5% for biofilter A (detention time 33.9 s) and 97.4% for biofilter B (detention time 67.8). The fresh compost could be used as a biofilter medium for odor control during composting process. The moisture content(MC) of the biofilter material increased by absorbing moisture from the exhaust gas, while the pH was decreased due to the degradation of nitrogenous compounds. As the moisture in the exhaust gas increased the MC of the biofilter, there was no need to spray water to the biofilter medium to control moisture content. While the total nitrogen(T-N) of the biofilter increased by absorbing ammonia, the total carbon (T-C) remained unchanged resulting in decrease of the C/N ratio.     

Nitrogen And Phosphorous Dynamics In Cocomposted Yard Trimmings And Broiler Litter

Total phosphorus, water-soluble phosphorus and total nitrogen concentrations in cocomposted yard trimmings and broiler litter were quantified in a 2 m wide × 1 m deep × 55 m long channel composter using batch mixing. The batch mixing occurred by using a rotor tiller type turner mounted on rails for the length of the composting channel. Phosphorus and nitrogen concentrations of the compost were measured as they varied with treatment and time during a 63 day compost process followed by a 30 day curing time. The treatments contained a single mix of 50% yard trimmings, 50% poultry litter, by volume, using four aeration and turning treatments. The first treatment was a control, which received no turning or aeration unless the moisture content dropped to 40% and additional water was added to bring the mix up to 50-55% moisture, mix consolidation was required, or mixing to obtain accurate samples and moisture contents, as necessary. Both treatments two and three were aerated by negative pressure ventilation. Treatment two was turned only when the moisture content dropped to 40% and additional water was added to bring the mix up to 50-55% moisture while treatment three was turned every two weeks or sooner if the moisture content approached 40% and additional water was added to bring the mix moisture up to 50-55%. Treatment four was not provided aeration but was turned, on a daily basis and additional water added as necessary, when the moisture content dropped to 40%, to bring the mix moisture up to 50-55%. Total phosphorus increased during the compost process while water-soluble phosphorus decreased during the 63-day active composting cycle from a high of slightly more than 1600 mg P/kg to a low of slightly less than 100 mg P/kg. Once the blowers were turned off and the mixes were no longer turned, soluble phosphorus concentrations were similar for all four treatments. However, after the 93 day cycle was complete, treatment one had almost twice the water-soluble phosphorus concentration as found in treatments two, three, and four. Total nitrogen increased during the final 30 days of the process for all four treatments. The increase was between 0.1 and 10 percent. No logical cause and effect has been established and this difference is believed to be random.     

牛粪堆肥化中氮素形态与微生物生理群的动态变化和耦合关系

在强制通风静态垛装置中研究了牛粪堆肥化中氮素形态和微生物生理群的动态变化。在堆制的56d里,根据堆温变化分阶段采集堆肥样品,测定各种氮素组分的含量和氮素微生物生理群的数量。结果表明,堆肥过程中,总氮减少了21．6％;有机氮是堆肥中的主要氮素形态,其含量降低了19．1％;氨基酸态氮和氨态氮的含量分别降低了20．9％和86．4％,在有机氮和总氮中的比例分别降低了2．2％和5．2％;氨基糖态氮和硝态氮含量分别增加了147％和79％,在有机氮和总氮中的比例分别增加了2倍和1．3倍。氨气的挥发占总损失的63％,高温期的释放量占总挥发量的69％。堆肥中氨化细菌数量较高,在高温期大幅度增加,其数量变化与堆肥中氨气和氨态氮含量都呈极显著正相关关系。在堆肥过程中,硝化细菌数量总体较小,在降温期增加幅度较大;反硝化细菌数量逐渐增加,堆制结束时达到堆肥初期的2．45倍;固氮菌数量总体增加1．8倍,其中降温期数量较多。堆肥过程中存在的反硝化作用,是氮素损失的另一个重要原因。     

Preliminary Study of the Effect of Continuous and Intermittent Aeration on Composting Hog Manure Amended With Sawdust

The effects of using intermittent aeration during composting on ammonia emissions and dry matter loss were determined during composting of hog manure amended with sawdust. Composting trials lasted three weeks and used pilot-scale 200 liter vessels (four). The experimental design used replication of two treatments, continuous aeration (CA) and intermittent aeration (IA), in two series of experiments (total of eight tests). In the CA sequence, compost temperatures were controlled at 60°C using feedback control on high and low air flow fans while the IA sequence consisted of five minutes of air flow followed by 55 minutes of rest. Mixing ratios of hog manure to sawdust were 1:1.1 and 1:1.7 dry weight basis with resulting C:N ratios of 18.2 ± 1.2 and 23.7 ± 2.2 for the two series of tests. Airflow reduction was 63 percent for IA compared to CA. Percent nitrogen loss between treatments were moderately statistically different (α = 0.14) with average percent nitrogen loss at 29.7 percent for CA and 23.0 percent for IA. Nitrogen loss as ammonia-N was higher for CA than IA (25.9 versus 14.3) but was not statistically different. No significant differences existed in dry solids loss between treatments and the physical and chemical properties of the compost produced from IA were similar to that from CA for each series. Results showed that IA compared to CA may be a practical way to reduce nitrogen loss and ammonia emissions during composting of swine manure with sawdust.     

Pilot and Full Scale Evaluations of Leaves as an Amendment in Sewage Sludge Composting

The use of leaf amendment in woodchips/sludge composting was studied in pilot-scale and full-scale operations. Use of leaves at a rate of 20 percent by volume was compatible with present practices and equipment at the Columbus Compost Facility, but higher rates caused materials handling and curing problems and would necessitate system modifications. Only very slight reduction in new woodchip usage was observed for the 20 percent leaf amendment, but output of sieved-finished compost was doubled. Leaf usage increased airflow requirement per unit dry matter during the initial stage of composting but decreased ammonia release throughout the composting process. On the other hand, use of recycled materials, compost and sieved woodchips, increased ammonia release. Adequate moisture and periodic turning in the pilot-scale studies enhanced composting for all treatments. Leaf usage may necessitate forced aeration during curing to keep full size piles aerobic. In addition, leaf usage increased the total materials handling requirement for operating the full-scale system by 16 percent, and it was concluded that careful consideration of materials handling is the major concern for a system's operating efficiency.     

膨松剂对厨余垃圾堆肥CH4、N2O和NH3排放的影响

厨余垃圾有别于混合生活垃圾,具有高有机质含量和高含水率等特点,单独堆肥会产生大量CH4、N2O、NH3和渗滤液,为减少厨余垃圾堆肥过程污染物的排放,该文以居民小区产生的经大类粗分后的厨余垃圾为研究对象,以菌糠为膨松剂,设置15%、25%、35% 3个添加质量比（湿基）的堆肥处理,以纯厨余垃圾单独堆肥为对照处理,研究菌糠作为膨松剂对厨余垃圾堆肥过程中CH4、N2O、NH3和渗滤液排放的影响及其最佳添加比例。结果表明,堆肥过程中,添加菌糠可以完全避免厨余垃圾堆肥过程中渗滤液的产生;堆肥结束时,添加15%和25%菌糠的处理堆肥达到腐熟标准,但添加35%的菌糠使堆肥高温期缩短,不利于有机质分解;与对照处理相比,添加15%、25%和35%比例的菌糠均可以减少堆肥过程中CH4和NH3的累计排放量,且减排量与添加比例正相关,但只有添加15%菌糠的堆肥处理明显降低了N2O的排放量;添加质量比为15%和25%菌糠的堆肥处理,CH4和N2O排放总量比厨余垃圾单独堆肥分别减少45.8%、19.6%,而添加质量比为35%的菌糠使CH4和N2O排放总量为厨余垃圾单独堆肥的1.14倍（每t物料,干基）。综上,菌糠作为食用菌种植废弃物,可用作厨余垃圾堆肥膨松剂,在适宜的添加比例条件下,能够在避免堆肥过程中渗滤液产生的同时,减少CH4、N2O和NH3的排放量。研究结果可为厨余垃圾堆肥过程温室气体减排、氮素损失控制和工艺改进提供理论依据和试验基础。     

A Comparison of Static Pile and Turned Windrow Methods for Poultry Litter Compost Production

Alternate technologies of compost manufactured from poultry litter (manure) were studied as a means of producing a value-added product for the landscape and nursery industry. Static pile and turned windrow technologies were investigated on a commercial scale with the composting of nearly 300 tons of material. The major difference between the technologies is the amount of energy and labor required. Static pile systems require less energy but more time than windrow turned systems. There was no process advantage found for passively aerated static piles over static piles but costs of passive aeration for pipes and labor were higher than for static piles. Machine turned windrows completed active temperature production within 100 days while portions of both the static and passively aerated piles continued to actively compost past 300 days. Process operational costs and compost quality were similar among the compost methods studied. Production operational cost is driven by the cost of compost ingredients and accounted for 60 to 70% of the cost in the pilot study. Ingredients were poultry litter, wood chips and sawdust. Screened compost was produced at an operational cost of $30 while unscreened compost could be produced for $20 per ton of compost. A production scheme where poultry litter is static pile composted on farms for later transport to regional processing centers appears feasible. This two-part composting procedure will eliminate the transport of raw litter and improve poultry biosecurity. Most likely, a private compost business would provide the expertise, on-farm compost procedures and operate the regional facility.     

Mass and Nutrient Losses During the Composting Of Dairy Manure Amended with Sawdust or Straw

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.     

Physical,Chemical and Biological Processes for Optimizing Decentralized Composting

On-site composting of nonpolluted organic wastes avoids costs and energy for transportation since the volume to be transported can be reduced to about 20% of the original. This paper describes the aerobic processes in a small-scale composting reactor, and evaluates how these processes can be optimized. The optimized composting process has a relatively short turnover time for organic matter; at the same time the temperature of about 60°C decreases the problems with pathogens and weeds in the mature compost. The compost produced has a high nutritional value, with high concentrations of especially nitrogen, potassium and phosphorus, while the contamination by heavy metals and other toxic substances are very low.