城市污泥生物干化处理及其在生态治理中的应用

利用城市污泥进行生物干化处理生产喷播绿化基材,应用结果表明,污泥喷播基材与边坡结合紧密,稳定性好,基材肥沃,灌木、草本种子发芽整齐,苗木生长旺盛;与传统的喷播绿化相比,能提前3—5d成坪,后期灌木根系发达,生长明显加速。     

脱水污泥生物干化及产物农用性质评价

城市污泥的生物干化及产物农用已引起越来越多的关注。本研究探讨了不同调理剂对生物干化堆体温度和产物含水率的影响,分析了干化过程中有机物的降解,及干化产物生物稳定性和重金属含量的变化趋势。结果表明：以稻草为调理剂的堆体最高温度可达67℃,干化产物含水率可从73%降至52%,产物4日耗氧呼吸速率降至10mgO·2g-1DM,显示了较好的稳定性。生物干化过程中,蛋白质和腐殖质含量逐渐降低,而多糖含量比较稳定。生物干化后产物重金属含量有所提高,除Zn部分超标外,其余重金属均未超出《农用污泥中污染物控制标准》（GB4284—1984）规定的限值。     

生物干化污泥对马尼拉草坪生长性状和环境效应的影响

为使城市生活污泥得以无害化、资源化综合利用,研究了经无害化处理的生物干化污泥对马尼拉草坪生长状况和土壤效应的影响。结果表明,随着生物干化污泥施用量的增加,马尼拉草叶绿素含量和生物量逐渐提高,但施用量超过1 250 g.m-2后,对马尼拉草的促进作用不再显著。生物干化污泥对马尼拉草坪具有较好的培肥效应,草坪土壤脲酶、蔗糖酶、过氧化氢酶活性显著提高。施用生物干化污泥还可提高土壤全氮、全磷、无机氮和速效磷含量,施用后不会造成土壤重金属污染。在园林绿地草坪使用,只要将施用量控制在1 250 g.m-2以下,是基本安全的,这为生物干化污泥在园林草坪上的推广应用提供科学依据。     

锯末添加量对餐厨废弃物生物干化效率和细菌群落的影响

餐厨废弃物存在含水率高、内部孔隙率低等问题,可以通过添加辅料来改善,适宜的辅料添加量有助于促进生物干化过程有机质降解和腐殖质形成,以提高生物干化效率。锯末作为一种富含碳源且低成本的辅料之一,近年来被广泛应用于各种废弃物资源化利用的研究中,但餐厨废弃物与锯末的配比如何影响微生物群落演替进而提升生物干化效率的过程机制尚不清楚。该研究在55 L生物干化反应器中,探究餐厨废弃物与锯末湿质量比为5:1(T1)、7:1(T2)和10:1(T3)三种处理对生物干化过程中的关键理化指标（包括温度、含水率、挥发性固体含量、电导率、酸碱度、种子发芽指数、总有机碳、总氮、总磷、总钾和碳氮比等）和细菌群落结构的影响。结果表明：与T1、T3相比,T2处理高温期持续时间最久,分别延长了50.00%、100.00%,在生物干化结束时含水率最低、有机质降解率最高,水分去除率达37.14%,挥发性固体降解率为15.88%;T2的种子发芽指数比T1、T3处理分别提前3、6 d达到80%以上,且在生物干化结束时,总养分含量升高28.32%,其中总磷含量升高最为显著,升高了121.62%,约为其他处理的1.92和1.90倍,...     

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。     

污泥堆肥过程中生物酶活性与理化因子关系分析

以污泥和稻草为原料,采用强制通风静态好氧系统与人工翻堆相结合的模式进行堆肥,测定堆肥过程各阶段纤维素酶、蛋白酶、脲酶、过氧化氢酶、磷酸酶的活性和pH值、全氮、氨态氮、硝态氮、全磷、速效磷、有机质的含量,并进行了相关分析和主成分分析。结果表明,堆体内不同高度的温度有着不同的变化趋势,堆肥初始阶段,堆体中层温度高于上层温度,随后上层温度逐渐高于中层温度。经过40d的堆肥化处理,堆肥产品达到腐熟标准,生物酶活性与堆肥理化因子呈现较好的相关性,说明生物酶活性可以表征堆肥肥力状况,生物酶活性还可以用来指示堆肥碳、氮、磷素转化情况,主成分分析显示脲酶、酸性、碱性和中性磷酸酶4类酶的活性在评价堆肥肥力中起主要作用。因此,生物酶活性可以作为堆肥肥力指标。     

曝气量与辅料粒径对餐厨废弃物辅热生物干化的影响

为解决餐厨废弃物生物干化处理周期长、脱水效率低的问题,该研究分别设置3个不同曝气量（0.4、0.6和0.8 L/(min·kg)）和不同辅料粒径（粗粒径>15.0 mm、细粒径<5.0 mm和混合粒径5.0～15.0 mm）进行析因试验,探究其对餐厨废弃物生物干化效果的影响。研究结果表明,相较于粒径而言,曝气量对于辅热生物干化温度变化和除水影响更大。0.6 L/(min·kg)曝气下升温速度较快,高温期持续时间更长,有效积温更高。除0.4 L/(min·kg)和细粒径处理,其他处理辅热生物干化过程高温期均超过7 d;0.8 L/(min·kg)和细粒径处理的除水效果最好,生物干化指数最高为4.0,最终含水率为17.0%,水分去除率为95.8%。能量和水分平衡计算表明：辅热生物干化过程中,主要的除水方式为蒸发除水,占总除水量40%～80%;主要能量来源为生物产热（63.0%～76.0%）,能量损失主要有蒸发潜热（26.0%～46.5%）和反应器热损失（28.3%～49.4%）,0.8 L/(min·kg)和细粒径处理的能量利用效率最高为65.1%。经过16 d辅热生物干化,除0.4 L/(min·kg)和细粒径处理pH值与发芽指数不能满足腐熟标准,其他处理均能完全腐熟,可满足有机肥标准。     

腌干鱼贮藏过程生物胺的变化及其货架期研究

为建立以生物胺变化预测腌干鱼在贮藏过程中品质和安全食用货架期的回归方程,以多脂的腌干带鱼和低脂的腌干金线鱼为原料,研究其在常温贮藏过程中的理化指标、主要微生物和生物胺的变化及相关关系,并应用逐步回归法进行回归分析,初步建立分析腌干鱼制品的货架期预测模型。结果表明,腌干带鱼和金线鱼在贮藏过程中p H、水分含量和Aw不断下降。葡萄球菌及微球菌、乳酸菌、菌落总数在贮藏3周内呈上升趋势,从第4周开始逐渐下降,而假单胞杆菌和肠杆菌在贮藏第4周之后未检出;组胺、尸胺和腐胺为腌干鱼贮藏过程主要胺类物质,呈上升趋势。5种生物胺(组胺、尸胺、腐胺、色胺、酪胺)、总生物胺量、生物胺相关指标、理化指标、假单胞杆菌均与贮藏时间高度相关,微生物中只有假单胞杆菌与生物胺及其相关指标有相关性;生物胺与理化指标也呈高度负相关。本研究结果为腌干鱼制品货架期体系的建立提供了参考依据。     

不同通风量下城市污泥堆肥过程中硫素的转化特征

  【目的】  研究通风量对城市污泥堆肥过程中硫素转化和挥发性硫化物释放的影响,为有效控制挥发性含硫恶臭物质,保留污泥堆肥产品中的硫素营养提供理论依据和方法。  【方法】  城市污泥和调理剂 (锯末) 以3∶1 (湿重) 的比例混合后,采用自动好氧堆肥控制装置进行15天的堆肥试验,通过改变鼓风机频率实现不同堆体的通风量调节。设置鼓风机工作频率10、13、16 Hz 3个处理,相应的通风量为2.5、3.0和3.5 L/min。在堆肥的第0、1、2、3、5、7、9、11、13、15天进行堆体内部多点混合采样,进行挥发性硫化物的浓度测定,研究城市污泥不同堆肥阶段硫素的转化特征。  【结果】  相较于低通风量 (10 Hz),高通风量 (16 Hz) 下H₂S的峰值浓度下降了约50%,但其累积释放量增加了45.4%;甲硫醚的累积释放量提高了398%,峰值浓度增加了490.8%;CS₂的累积释放量下降了57.8%,其峰值浓度下降了77%。堆肥产品中有效硫浓度在低、中、高通风量条件下相较于堆肥前分别上升了19.5%、19.1%、36.1%。  【结论】  城市污泥堆肥过程中,提高通风量可以降低H₂S的浓度峰值,但增加了H₂S的累积释放量,甲硫醚的峰值浓度和累积释放量均显著增加;提高通风量可以抑制城市污泥堆肥过程中CS₂的释放。在低、中、高3种通风量条件下,堆肥产品的有效硫浓度相较于堆肥前都明显升高。高通风处理虽然全量硫的损失最大,但更有利于提高堆肥产品中可直接被植物吸收的有效硫含量。     

污泥厌氧消化过程的流变规律与脱水性能

为阐明厌氧消化过程中污泥流变学与污泥理化性能(脱水性能)之间的关联及低温水解预处理对污泥厌氧消化产气的影响,对常规污泥及低温热水解预处理污泥进行厌氧消化试验,结果表明试验结束时,低温热水解-厌氧消化的挥发性固体(volatile solids, VS)去除水平较常规厌氧消化污泥提高3.7个百分点,低温热水解预处理也使得消化污泥的脱水性提高1.59%;污泥屈服应力分别了降低了64.51%和71.47%;稠度系数分别减小了90.94%和92.83%,污泥流动性增强。整个消化过程VS/总固体(totalsolids,TS)和屈服应力随时间的变化均呈对数下降趋势;通过线性方程拟合和皮尔逊相关性分析表明,屈服应力与VS/TS、屈服应力变化与脱水性能改善两两间的拟合优度(R^2)均大于0.94,表明在厌氧消化过程中屈服应力、屈服应力变化与污泥VS/TS、脱水性能具有较好的线性关系。研究结果从流变学角度为厌氧消化过程中的监控和优化提供新思路和理论依据。     

Behaviour of cadmium and nickel in a soil amended with sewage sludge

Various urban and industrial sewage sludges were applied to a soil at two doses (50 and 100 t ha⁻¹ y⁻¹) during eight years in a field experiment. The soil was analysed at two depths (0–30 and 30–60 cm) for extractable cadmium and nickel. In general these trace metal increased with dosage. However, cadmium formed complexes with organic matter and nickel bound to iron and manganese oxides. Hence, the available fractions of these metals constituted a small proportion of the total content. The results obtained show a low risk of contamination due to the available fractions of these metals at sludges dosages of up to 100 t ha⁻¹. Copyright © 2001 John Wiley & Sons, Ltd.     

Initial organic matter transformation of soil amended with composted sewage sludge

 An incubation experiment with composted sewage sludge (CSS) just added to the soil was conducted to determine its initial effects on C decomposition, N nitrification and the transformation of organic matter. CSS was mixed with a sandy loam soil from uncultivated ochric epipedon of a Typic Haploxeralf at rates of 0, 40 and 80 t ha^–1 (dry weight). The data obtained showed that with regard to the unamended soil, both the 40 and the 80 t ha^–1 treatments produced the same result in decreasing respiratory activity, but the addition of increasing amounts of CSS progressively delayed C decomposition. The nitrification index (NI), defined as the relation between nitrate-N and nitrate-N + ammonium-N, increased in correlation with the C mineralization coefficient. Total organic matter decreased after incubation whereas the humic substances increased in relation to the total C mineralized. Received: 28 October 1999     

Effects of the application of heated sewage sludge on soil nutrient supply to plants

Abstract

We previously reported that heating sewage sludge significantly changes the rate of N mineralization. The present study was undertaken to examine the extent to which these changes affect plant growth and nutrient supply after application to different soils. A pot experiment in which komatsuna plants (Brassica campestris L. var. rapa) were grown in a Fluvisol or an Arenosol indicated that the amount of N taken up by the plants increased significantly by heating air-dried sludge at 120°C and decreased significantly by heating at 180°C. Heat-drying of the sludge at 120°C or 180°C also increased the N uptake significantly. These plant responses could be explained by the heat-induced changes in the release of inorganic N from the sludge. In contrast to N, the sludge materials containing Fe as a coagulant immobilized soil soluble P. When the sludge was applied to an Andosol, the N-supplying effects on plant growth were offset by P adsorption onto the sludge and soil. In a successive pot experiment conducted without additional sludge application, it was further suggested that frequent sludge application is required to maintain plant growth. However, it will also lead to the accumulation of sludge components in the soil because less than 40% and 15% of the sludge N and P, respectively, were apparently recovered in two harvests of the plants. In conclusion, heated sludge materials can act as an effective organic N fertilizer provided that they are applied to a suitable soil and that the short-term effects on soil productivity are balanced with the long-term effects on environmental quality.     

聚环氧琥珀酸对污泥中镉的萃取作用

Polyepoxysuccinic acid (PESA), as an environmental benign biodegradable chelant, was used to remove heavy metals from the sewage sludge of Shanghai Taopu Wastewater Treatment Plant. The extraction of cadmium (Cd) from sewage sludge using aqueous solution of PESA was studied. It was found that PESA was capable of extracting Cd from the sludge, and the extraction efficiency was dependent on both pH and the concentration of the chelating reagent. The extraction efficiency decreased gradually with increasing of pH, whereas the dependency on pH decreased as the concentration of PESA increased. In the case of the high PESA to total metal ratio, e.g., 10:1, the extraction efficiency reached above 70% within the pH range from 1 to 7. The highest extraction efficiency obtained in the experiment was 78％. By comparing the contents of the heavy metals in sewage sludge before and after the extraction, it was found that the extracted Cd came mainly from the four fractions: acid-soluble, reducible, oxidizable, and water-soluble fractions.     

皂角苷对几种生活污泥中和的去除

为探讨皂角苷对污泥中Cu和Zn去除的机制,采用化学淋洗的方法研究皂角苷浓度（0~7%）、pH（2~6）、振荡时间（0~48 h）、温度（10、25、40℃）和提取次数（1~4次）对四种生活污泥中Cu和Zn去除率的影响,分析去除前后重金属的形态,并监测去除过程中浸出液pH的变化。结果表明,单次淋洗条件下,皂角苷对Cu的去除率大于Zn;皂角苷溶液的pH对Cu的去除没有显著影响,而Zn的去除率在pH下降到2时明显增加;Cu经过6~12 h的振荡就能达到最大去除,Zn则需要经过较长时间的振荡（48 h）才能达到较好去除;提高振荡温度,Cu的去除率降低而Zn的增加;随着提取次数的增加,Cu和Zn的去除率均增加,Cu的去除以第1次提取为主,Zn的4次提取均有较好效果,用3%的皂角苷溶液连续4次提取后,Cu和Zn的累积去除率最大分别达到32.61%和39.32%;增加振荡时间、提高振荡温度、增加提取次数以及降低皂角苷溶液pH均能降低浸出液的pH。经过3%的皂角苷溶液的提取,污泥中各形态Cu的含量均减少,其中66%以上的酸溶态被去除;而Zn的酸溶态含量减少不明显,可还原态、可氧化态和残渣态均有所降低,但以残渣态的减少为主。     

绿化植物废弃物和污泥的堆肥特性研究

绿化植物废弃物和污泥不同比例的堆肥实验显示其质量比为5∶4时堆肥升温快,高温持续时间最长;全碳和全氮含量在堆肥14 d后都有明显的降低;NO3--N的含量变化不大;NH4+-N的含量降低;堆肥的富里酸(FA)快速降低,胡敏酸(HA)先略有降低,然后快速增加;而种子发芽指数在14 d后均超过了0.8;最终腐殖质化参数(HI)为2.71,腐殖化速率(HR)为14.87%,CFA/CO=10.8;重金属的含量符合相关堆肥标准要求。绿化植物废弃物的高木质素含量决定了C/N、T值(终点C/N)/(初始C/N)、NH4+-N/NO3--N不宜作为其腐熟评价指标,但温度、NO3--N和NH4+-N、腐殖化参数、种子发芽指数可作为绿化植物废弃物和污泥混合堆肥的腐熟评价指标。绿化植物废弃物和污泥混合堆肥效果取决于污泥的添加量,含水量高的污泥用量过多会影响堆肥效果。绿化植物废弃物和污泥综合利用对控制堆肥质量,提高废弃物综合利用,促进城市节能减排有重要意义。     

Determination of organic matter in sewage sludges

Abstract

Procedures for determining organic matter indirectly and directly in sludges are described. A good agreement between chromic acid oxidation and dry—combustion elemental analysis methods of determining organic‐C was observed. Sludge organic matter content was determined directly by loss‐on‐ignition by thermal analysis. An average C factor of 1.68 to estimate the organic matter from organic‐C, obtained by chromic acid oxidation method, was calculated for aerobically digested sludges.