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城市污泥的合理处置是目前资源与环境科学研究领域中的重要课题之一.城市污泥因富含大量的有机质和有效营养成分,对农业土壤肥力、土壤物理结构和农业生产均有一定的积极促进作用,使得污泥农用成为可能.但城市污泥中含有的重金属、有机污染物等有害物质尤其是重金属,成为污泥农用处置的瓶颈.为提高我国城市污泥的农业资源化利用效率和减少污染物造成的负面效应,本文就国内外施用城市污泥对植物-土壤互作系统的影响及过程进行了综述,为进一步提高污泥利用效率提供理论依据和科学指导. 相似文献
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分别于2008年4月至6月和2009 年4月至6月, 采用目标动物取样法在黑龙江省安邦河湿地和大庆龙凤湿地研究了骨顶鸡等水鸟对人为干扰的行为响应。结果表明:骨顶鸡对行人和机动车辆两种干扰的反应距离类似,但耐受程度有所不同,骨顶鸡对机动车辆干扰的耐受性要好于行人干扰。在以游客等行人干扰为主的安邦河湿地,骨顶鸡以及其他游禽对干扰产生行为反应的比例要高于以机动车辆干扰为主的龙凤湿地,说明相对于行人干扰骨顶鸡对机动车辆更容易耐受;在安邦河湿地,骨顶鸡对划船的反应距离以及反应程度要大于人行走,说明骨顶鸡对于侵入性的干扰更为敏感。此外,对凤头(Podiceps cristatus)、黒颈(Podiceps nigricollis)、小(Tachybaptus ruficollis)、黑水鸡(Gallinula chloropus)、红头潜鸭(Aythya ferina)、赤膀鸭(Anas strepera)、绿头鸭(Anas platyrhynchos)、斑嘴鸭(Anas poecilorhyncha)、绿翅鸭(Anas crecca)、白眉鸭(Anas querquedula)、赤颈鸭(Anas penelope)、琵嘴鸭(Anas clypeata)等游禽对人为干扰的反应距离、耐受距离以及遭受干扰时的反应比例进行了研究,结果显示3种对干扰的耐受距离差异不显著,12种鸭类中红头潜鸭对人为干扰的敏感性要小于其他鸭类,斑嘴鸭和绿头鸭则相对敏感。 相似文献
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邻苯二甲酸酯(PAEs)是城市污泥中普遍存在的一类具有内分泌干扰性作用的有机污染物.研究污泥厌氧生物处理过程中PAEs的微生物降解对保障污泥农用的安全性十分必要.本文以污泥中两种主要的PAEs——邻苯二甲酸二丁酯(DBP)和邻苯二甲酸(2-乙基己)酯(DEHP)为研究对象,通过比较PAEs在污泥厌氧消化系统与发酵产氢系统中降解过程的差异及系统污泥特性的变化,分析不同污泥厌氧生物处理系统中影响PAEs降解的可能因素.结果表明: 在污泥厌氧发酵系统中,DBP在6 d内降解率达99.6%, DEHP在整个14 d的培养期间也降解了46.1%;在发酵产氢系统中,在14 d培养过程DBP的降解率仅为19.5%,DEHP则没有明显的降解.与厌氧消化系统相比,PAEs在发酵产氢系统中的降解受到明显抑制,这与发酵产氢过程中微生物量下降、革兰氏阳性菌/革兰氏阴性菌(G+/G-)和真菌/细菌变小及挥发性脂肪酸(包括乙酸、丙酸及丁酸)浓度升高有关. 相似文献
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Michele A. Parisien Allison Rutter Barbara A. Zeeb 《International journal of phytoremediation》2015,17(11):1137-1143
Greenhouse and in-situ field experiments were used to determine the potential for phytoextraction to remediate soil contaminated with Cd from municipal solid waste (MSW) and sewage sludge (SS) compost application at a Peterborough (Canada) site. For the greenhouse experiment, one native (Chenopodium album) and three naturalized (Poa compressa, Brassica juncea, Helianthus annuus) plant species were planted in soil containing no detectable Cd (<1.0 μg·g?1), and soil from the site containing low (5.0 ± 0.3 μg·g?1 Cd), and high (16.5 ± 1.2 μg?g?1 Cd) Cd concentrations. Plant uptake was low (root BAFs ≤0.5) for all species except P. compressa in the low Cd treatment (BAF 1.0). Only B. juncea accumulated Cd in its shoots, though uptake was low (BAF ≤0.3). For the field experiment, B. juncea was planted in-situ in areas of low and high Cd concentrations. Brassica juncea Cd uptake was low (root and shoot BAFs <0.2) in both treatments. Sequential extraction analysis indicated that Cd is retained primarily by low bioavailability soil fractions, and phytoextraction is therefore not feasible at this site. Though low Cd bioavailability has negative implications for Cd phytoextraction from MSW/SS compost-based soils, it may limit receptor exposure to Cd sufficiently to eliminate the potential for risk at this site. 相似文献
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AbstractElectrometric studies were carried out on the interaction of heavy metal ions such as manganese, chromium, nickel, copper, zinc, cadmium and lead with the extracted organic matter, humic and fulvic acid from the sludge in a sewage oxidation pond. The distribution of heavy metals was between 60 and 97%, which is associated with the solid waste (sludge) of the oxidation pond. The adsorption/removal efficiency of metal ions onto the sludge ash was more than 90% and 97%, respectively, in the pure system. To obtain the ash, the sludge was burnt at 500°C, treated with nitric acid (1+1) to leach out all the metals and then filtered; the residue left on the filter paper was the pure ash. Both this and that coated with organic matter were studied. The adsorption isotherm for metals, humic/fulvic acids and metal-humic/fulvic acid complexes in the metal-free sludge ash and in the organic matter in the pure system were studied using the Freundlich relationship. Good agreement was found suggesting that sediment and humic/fulvic acids have an important role in the mobility, dispersion and sedimentation of metal ions in an aquatic environment. More of these heavy metals are removed in the pure system than in the natural system. This may be due to the lesser availability of humic and fulvic acids in the lagoons during the short detention time of sewage in suspension in the oxidation pond, whereas the sludge which has settled to the bottom of the pond for several years contains rich decomposed organic matter in the form of humic and fulvic acids containing heavy metals. Such pure systems could be useful for the effective removal of heavy metals. 相似文献
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Breeding populations of the common loon (Gavia immer) in Michigan have declined in the past several decades, resulting in classification of this species as threatened under state law. Factors responsible for the decline are unknown, but may include toxic contaminants, mortality in commercial fish nets, and human disturbance of breeding sites. To assess the latter possibility, 960 hours of observation were devoted to observing human-loon interactions on two sets of lakes, one with restricted human use (minimal or no shoreline development and open to canoe use only), and another with unrestricted use (varying amounts of shoreline development and motorboat traffic). Six mated pairs of loons on six restricted use (r-u) lakes were compared to eight loon pairs on seven open-use (o-u) lakes. The number of nests that hatched young per nest started was not significantly different between the two sets of lakes (7 of 13 (0.62) on r-u lakes vs 8 of 17 (0.47) on o-u lakes), despite significantly more human activity on o-u lakes. Chicks hatched per pair of loons were likewise not significantly different (1.1 vs 1.2 on r-u and o-u lakes, respectively). Fledging success was significantly lower on r-u lakes (7 chicks fledged of 11 hatched) than on o-u lakes (13 fledged of 13 hatched). Human activity on o-u lakes was 2–3 times that on r-u lakes during chick rearing, but time spent by adult loons tending and feeding chicks was not significantly different between the two types of lakes. The larger size of most o-u lakes may have allowed loons a greater opportunity to avoid human disturbance. Higher levels of human activity did not affect production of chicks by loons under the conditions observed, but these results should not be extrapolated to lakes experiencing much higher human use. 相似文献
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Captive adult common marmosets (Callithrix jacchus) produce whistlelike “phee” calls in two contexts: in the home cage, where phee calls may function as part of territorial marking behavior, and when separated from social companions, where phee calls may function to reunite conspecifics. Natural and synthesized calls representing the acoustic structure of male and female calls in each context were presented to adult marmosets in a playback paradigm. Marmosets demonstrated discriminative abilities according to the context of the call and the caller's sex. Vocal and behavioral responses indicated increased vigilance and territorial behavior, following playbacks of naturally produced calls as well as synthetic calls. All animals scanned more frequently following produced calls as well as synthetic calls. All animals scanned more frequently following natural home cage as well as isolation calls, but only increased contact behavior (trills) in response to home cage calls. The responses were dimorphic according to the sex of the caller, where adult males scanned more following male calls, and adult females were more aggressive following male and female calls. The differential behavioral responses to playbacks of marmoset phee calls suggest a biological relevance to subtle differences found in the acoustic parameters of the phee call. © 1994 Wiley-Liss, Inc. 1 This article is a US Government work and, as such, in the public domain in the United States of America. 相似文献
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Wen Guang Bates T. E. Inanaga S. Voroney R. P. Hamamura K. Curtin D. 《Plant and Soil》2002,246(2):241-248
Organic wastes such as sewage sludges contain copper (Cu). Increased attention to environmental protection requires that wastes be treated with pathogen-eliminating procedures before application to farmland. It is not clear, however, if such procedures affect the plant availability of Cu in the wastes. This 2-year field research investigated the effect of irradiation and composting on Cu availability in sludges and manure using a yield control approach. Four organic wastes [digested and dewatered (DSS), digested and irradiated (DISS), composted (DICSS) sewage sludges and composted livestock manure (CLM)] were applied at four rates (10, 20, 30 and 40 t solid ha–1 year–1) with supplemented N and K fertilizers. A control treatment (CT) received N and K fertilizers only. Beans, lettuce and petunias were grown in first year and lettuce were harvested twice in second year. Beans appeared to have a strong ability to absorb Cu compared with the other test crops. In general, crop Cu concentration responses to Cu applied in DSS and DISS were well described by quadratic equations. Tested by a paired t-test, Cu concentration in bean pods was higher in DISS than in DSS treatment, indicating that irradiation increased phytoavailability of Cu. However, the parabolic response of crop Cu to Cu applied in DISS, suggesting that the increases were confined to the lower rates of DISS. Copper applied in DICSS did not increase Cu concentration in any of the test crops. At a given level of applied Cu, crop Cu tended to be lower in DICSS than in DSS or DISS treatment. Sludge composting depressed phytoavailability of Cu. Copper concentration in CLM was much lower than in sludges and sludge composts, but application of CLM increased Cu concentration in bean pods. The pattens of Cu concentration in the two cuts of lettuce in 1991 to Cu applied in CLM were similar, where low rates of CLM application slightly reduced Cu concentration, then the Cu concentration increased with increased rates. The dynamics of available Cu supply were different in the sludge composts and manure composts. 相似文献
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The present study was conducted to assess the suitability of sewage sludge amendment (SSA) in soil for Beta vulgaris var. saccharifera (sugar beet) by evaluating the heavy metal accumulation and physiological responses of plants grown at a 10%, 25%, and 50% sewage sludge amendment rate. The sewage sludge amendment was modified by the physicochemical properties of soil, thus increasing the availability of heavy metals in the soil and consequently increasing accumulation in plant parts. Cd, Pb, Ni, and Cu concentrations in roots were significantly higher in plants grown at 25% as compared to 50% SSA; however, Cr and Zn concentration was higher at 50% than 25% SSA. The concentrations of heavy metal showed a trend of Zn > Ni > Cu > Cr > Pb > Cd in roots and Zn > Cu > Ni > Cr > Pb > Cd in leaves. The only instance in which the chlorophyll content did not increase after the sewage sludge treatments was 50%. There were approximately 1.12-fold differences between the control and 50% sewage sludge application for chlorophyll content. The sewage sludge amendment led to a significant increase in Pb, Cr, Cd, Cu, Zn, and Ni concentrations of the soil. The heavy metal accumulation in the soil after the treatments did not exceed the limits for the land application of sewage sludge recommended by the US Environmental Protection Agency (US EPA). The increased concentration of heavy metals in the soil due to the sewage sludge amendment led to increases in heavy metal uptake and the leaf and root concentrations of Ni, Zn, Cd, Cu, Cr, Pb, and Zn in plants as compared to those grown on unamended soil. More accumulation occurred in roots and leaves than in shoots for most of the heavy metals. The concentrations of Cd, Cr, and Pb were more than the permissible limits of national standards in the edible portion of sugar beet grown on different sewage sludge amendment ratios. The study concludes that the sewage sludge amendment in the soil for growing sugar beet may not be a good option due to risk of contamination of Cr, Pb, and Cd. 相似文献
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Isolation of bacteria producing polyhydroxyalkanoates (PHA) from municipal sewage sludge 总被引:1,自引:0,他引:1
S. Vishnuvardhan Reddy M. Thirumala T. V. Kishore Reddy S. K. Mahmood 《World journal of microbiology & biotechnology》2008,24(12):2949-2955
Bacterial isolates from sludge samples collected at a local municipal sewage treatment plant were screened for bacteria producing
polyhydroxyalkanoates (PHA). Initially Sudan black B staining was performed to detect lipid cellular inclusions. Lipid-positive
isolates were then grown in a nitrogen limitation E2 medium containing 2% (w/v) glucose to promote accumulation of PHA before
the subsequent staining with Nile blue A. The positive isolates were quantified initially with a u.v. spectrophotometer, for
a very large number of isolates (105) and among them high PHA-producing isolates (15) were selected and were confirmed by
gas chromatographic analysis. The GC analysis showed the polymers produced by 13 of the selected isolates to be polyhydroxybutyrate
(PHB), and the remaining two isolates produced polyhydroxybutyrate-co-hydroxyvalerate (PHB-co-HV) copolymer. The proportion
of the PHA-positive bacterial isolates showed variability in the number of PHA accumulators during various months. The correlation
of PHB production with the cell dry weight (CDW) was found to be statistically significant. The metabolism of PHB in these
selected 15 isolates was studied using the Nile blue A staining, which showed an initial increase in the fluorescence followed
by a decline, on further incubation. All the selected 15 isolates were classified to genus level by studying their morphological
and biochemical characteristics. There were seven Bacillus species, three Pseudomonas species, two Alcaligenes species, two Aeromonas species, and one Chromobacterium species. 相似文献
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通过对冬季室内和室外分别生长30d的冬小麦在节律性和非节律性融冻变温过程中抗氧化酶活力和渗透调解物含量变化的分析,揭示其在冬小麦适应日融冻胁迫中的作用。结果表明:生育期不同的室内(均温11℃,拔节期)和室外(均温1℃,分蘖静滞期)冬小麦叶片抗氧化酶和脯氨酸对日光强和温度节律变化的响应趋势是一致的,即随日出而增高,中午气温较高时最高,日落而降低;在非节律性变温处理中,室外冬小麦抗氧化酶活力和脯氨酸含量随气温上升至18℃而增高,气温迅速下降到-2.5℃而降低,经历冻-融-冻胁迫冬小麦生长良好。室内冬小麦抗氧化酶活力随气温降低到-6℃,叶片结冻,迅速下降,气温升高到18℃而增加,经历融-冻-融胁迫后植株死亡;室外冬小麦光合速率(Pn)和比室内的低,而抗氧化酶活力高于室内;冬小麦快速提高抗氧化酶活力和脯氨酸含量,抑制氧自由基积累、维护细胞水分平衡,这在适应冬季节律性融冻胁迫中起重要作用;暖冬中冬小麦较高的Pn和较低的抗氧化酶活力可能是引起冬小麦在"倒春寒"中死亡的生理原因。 相似文献
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To investigate carbon and nitrogen metabolism in Pyropia haitanensis in response to the combined conditions of ocean acidification and diurnal temperature variation, maricultured thalli were tested in acidified culture under different temperature treatments. The results showed a combined effect of ocean acidification and diurnal temperature difference on the C and N metabolism and growth of P. haitanensis. In acidifed culture, algal growth, maximum photosynthetic rate, nitrate reductase (NR) activity, amino acid (AA) content and AA score (AAS) were more significantly enhanced in seaweed under diurnal temperature variation than in seaweed at constant temperature. In acidified seawater, soluble carbohydrates in P. haitanensis increased due to greater dissolved inorganic carbon (DIC), whereas soluble proteins decreased. Under the diurnal temperature treatment, higher temperature during the light period enhanced accumulation of algal photosynthates, whereas lower temperature in the dark period reduced energy consumption, resulting in enhanced algal growth, AA content and AAS. We concluded that suitable diurnal temperature difference would be conducive to C fixation and N assimilation under ocean acidification. However, excessively high temperatures would depress algal photosynthesis and increase energy consumption, thereby exerting a negative effect on algal growth. 相似文献
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Nitrogenase activity in Alnus incana root nodules. Responses to O(2) and short-term N(2) deprivation 下载免费PDF全文
Lundquist PO 《Plant physiology》2000,122(2):553-562
O(2) and host-microsymbiont interactions are key factors affecting the physiology of N(2)-fixing symbioses. To determine the relationship among nitrogenase activity of Frankia-Alnus incana root nodules, O(2) concentration, and short-term N(2) deprivation, intact nodulated roots were exposed to various O(2) pressures (pO(2)) and Ar:O(2) in a continuous flow-through system. Nitrogenase activity (H(2) production) occurred at a maximal rate at 20% O(2). Exposure to short-term N(2) deprivation in Ar:O(2) carried out at either 17%, 21%, or 25% O(2) caused a decline in the nitrogenase activity at 21% and 25% O(2) by 12% and 25%, respectively. At 21% O(2), nitrogenase activity recovered to initial activity within 60 min. The decline rate was correlated with the degree of inhibition of N(2) fixation. Respiration (net CO(2) evolution) decreased in response to the N(2) deprivation at all pO(2) values and did not recover during the time in Ar:O(2). Increasing the pO(2) from 21% to 25% and decreasing the pO(2) from 21% to 17% during the decline further decreased rather than stimulated nitrogenase activity, showing that the decline was not due to O(2) limitation. The decline was possibly due to a temporary disturbance in the supply of reductant to nitrogenase with a partial O(2) inhibition of nitrogenase at 25% O(2). These results are consistent with a fixed O(2) diffusion barrier in A. incana root nodules, and show that A. incana nodules differ from legume nodules in the response of the nitrogenase activity to O(2) and N(2) deprivation. 相似文献
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Wen Guang Bates T. E. Voroney R. P. Yamamoto T. Chikushi J. Curtin D. 《Plant and Soil》2002,246(2):231-240
The threat of spreading diseases is a serious concern when organic wastes are applied to farmland. Irradiation and composting are effective methods to reduce pathogens. Field experiments were conducted to assess the influence of these pathogen-eliminating methods on plant availability of Zn in the wastes. Four organic wastes: digested and dewatered (DSS), irradiated (DISS), composted (DICSS) sewage sludge and composted livestock manure (CLM) were applied during two growing seasons at 10, 20, 30, and 40 t solids ha–1 year–1. Available N and K in the wastes were estimated and N and K fertilizers were added to the soil to equalize available N and K supply among treatments to avoid dilution of crop Zn concentration. A control treatment (CT) received fertilizers but no waste. Lettuce, snap beans and petunias were grown in 1990, and two cuts of lettuce were harvested in 1991. The influence of waste Zn application on crop Zn concentration was studied within approximately equal crop yields. Crop Zn concentration increased in all crops treated with DSS or DISS, and often reached a maximum at the 30 t ha–1 rate of application, then slightly decreased at 40 t ha–1. The response of crop Zn concentration to the amount of Zn applied in the wastes was best described by quadratic equations. Waste application also significantly increased soil Zn availability index, which was a function of DTPA (diethylenetriamine pentaacetic acid)-extractable soil Zn and soil pH. The index was highly correlated with crop Zn concentration. Although Zn concentration in DICSS was similar to those in DSS and DISS, Zn applied in DICSS did not increase crop Zn concentration or soil availability index. Composting reduced the availability of Zn. The similar concentrations of Zn in DSS and DISS in both years allowed the use of a paired t-test to determine the differences in crop Zn concentration caused by application of DSS and DISS. Zinc applied in DISS produced a higher Zn concentration in bean pods than Zn applied in DSS (t > T
0.05 at P < 0.02, df = 15), indicating that irradiation increased phytoavailability of Zn in the sludge. However, no similar effect was found in Zn concentrations in the two cuts of lettuce in 1991 or in soil Zn availability index. 相似文献
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采用13C-CO2进行连续标记,研究水稻分蘖期和孕穗期光合碳在植株-土壤系统中的分配及其对大气CO2浓度升高(800 μL·L-1)和施氮(100 mg·kg-1)的响应.结果表明: CO2浓度升高显著提高分蘖期根系生物量和孕穗期地上部生物量,并使生物量根冠比在分蘖期增加,而在孕穗期减小.CO2浓度升高条件下,施氮使水稻地上部分生物量增加,却显著降低了孕穗期水稻根系生物量.CO2浓度升高使光合13C在孕穗期向土壤的输入显著增加,然而施肥并没有促进由CO2浓度升高驱动的光合13C在土壤中的积累,而且还降低了土壤中的光合13C的分配比例.综上,CO2浓度升高显著提高了稻田土壤光合碳输入,促进稻田有机碳周转;施氮促进了水稻地上部的生长,却降低了光合碳向地下的分配比例. 相似文献
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Almudena Hospido Teresa Moreira María Martín Miquel Rigola Gumersindo Feijoo 《The International Journal of Life Cycle Assessment》2005,10(5):336-345
Background, Aims and Scope Huge amounts of sewage sludge, that need to be handled, are generated all around the world from wastewater treatment plants
and its management in an economically and environmentally acceptable way has become a matter of increasing importance during
the last few years.
In this paper, we make use of Life Cycle Assessment (LCA) to compare biological and thermal processes, that is to say, anaerobic
digestion versus pyrolysis and incineration. This paper will complete the analysis performed in a wastewater treatment plant,
where sludge post-treatment was identified as one of the main contributors to the environmental impact on the global system.
Methods LCA is a tool for evaluating the environmental performance of goods as well as processes or services (collectively termed
products). ISO 14040 defines LCA as a compilation and evaluation of the inputs, outputs and the potential environmental impacts
of a system throughout its life cycle: from the production of raw materials to the disposal of the waste generated.
In this study, data relating to the actual scenario from an existent wastewater treatment plant were considered. Both bibliographical
and real data from existing facilities were used for the thermal processes proposed.
The Centre of Environmental Science (CML) of Leiden University's methodology was chosen to quantify the potential environmental
impacts associated with the different scenarios under study. The software SimaPro 5.1 was used and CML factors (updated in
2002) were chosen for characterisation and normalisation stages.
Results and Discussion In a previous study, sewage sludge was found to be a critical point in the environmental performance of a wastewater treatment
plant, so different alternatives have been tackled here. Anaerobic digestion followed by land application of pasty sludge
comprises both energy recovery and nutrient recovery. Other thermal processes, such as incineration or pyrolysis, allow energy
recovery (both electrical and thermal) and, although nutrients are lost, new co-products are produced (tar and char at pyrolysis).
Here, the most adverse case (that is to say, the total amount of heavy metals is supposed to be released from the sludge and
reach the environment) was applied to consider the most negative impact due to sludge spreading in agricultural soils; so
more research is required in order to establish the precise amount of heavy metals that is effectively uptaken by the plants
and crops as well as the amount that is transferred to another phase as a leachate.
Thermal processes are presented here as a good option to recover energy from the sludge; although the value of nutrients is
lost. Tar and char, co-products from pyrolysis, are good examples that were evaluated here, recycling of bottom ashes from
sludge incineration or manufacture of ceramic materials from sludge are other options to be studied in the near future.
Conclusion During the last few years, several opinions have been declared in favour of land application, incineration or pyrolysis,
but many voices have also spoken out against each one. To obtain general conclusions for an overall comparison of different
post-treatment of urban wastewater sludge is not easy as there are many contradictory aspects. The most effective utilisation
of sewage sludge implies both energy and material re-use, but this is not always possible. Nevertheless, we think that land
application of digested sludge is an acceptable option, probably not the best but at least a good one, for sludge treatment
as long as efforts are focused on the minimisation of heavy metal content in the final cake. 相似文献