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1.
Abstract

The effectiveness of a new organic soil conditioner from the co‐composting of olive oil processing wastewater and solid residue was examined through the evaluation of some of its physical and chemical characteristics. The concentration of 25% w/w of this material into the conditioner‐soil mixtures appears to be the maximum level for the cultivation of tomato plants. The plants grown on this conditioner‐soil mixture were 1.52±8.5% times larger than those grown on a sandy loam soil. The pure conditioner cannot be used as a substrate for the growth of tomato plants. The water‐holding capacity of the conditioner was almost two times higher than that of the pure soil and remained almost stable for temperatures between 8–40°C. The apparent density of the conditioner was 0.5 times smaller than that of the pure soil. With increased application rate of the conditioner to the soil, there was a decrease in the pH, an increase in the specific conductivity, and an increase in the ammonium‐nitrogen (NH4‐N) and phosphorus (P) concentration of the mixture.  相似文献   

2.
The main objective of this study was to analyse how different sewage sludges influence soil wetting and drying dynamics. Three composted and three thermally‐dried municipal sludges from different wastewater plants located in Catalonia (NE Spain) were mixed with a mine‐soil obtained from a limestone quarry. Measurements of the time required to reach zero contact angle () and water holding time (WHT) provided information on the time required for a mine‐soil to reach its complete wettability and the residence time of water stored between ?0.75 and ?25 MPa of soil suction, respectively. One month after sludge amendments, one composted and one thermally‐dried sludge significantly increased . WHT was increased in the mine‐soil treated by composted sludges (50.6% by Blanes' sludge, 65.5% by Manresa's sludge and 52.5% by Vilaseca's sludge) one month after sludge amendments. The amount of water retained in the mine‐soil was increased by all composted sludges and one thermally‐dried sludge after one month (by 42.3% with Blanes' sludge, 42.3% with Manresa's sludge, 65.7% with Vilaseca's sludge and 23.9% with Mataró's sludge) and one year after sludge amendments and at a small suction. Increments in WHT corresponded with the amount of water retained so the time‐scale of soil water availability should also be considered. The value was modified mainly by increments in carbon stock and microbial biomass, while the WHT was modified mainly by increments in pH and electrical conductivity. Under similar air‐drying conditions, mine‐soil treated with composted sludges retained more water for longer compared with thermally‐dried sludges.  相似文献   

3.
Pulp and paper sludge is a by-product of paper production and may be suitable in agricultural applications as a soil amendment or mulch. The objective of this study was to evaluate raw and composted pulp and paper sludge as soil additives or mulches for cottonwood plants. Primary sludge, a combination of by-products from bleached kraft and neutral sulfite semichemical paper, was mixed with tailings, slaughterhouse paunch, and 10 percent wood ash (by volume), and used raw or composted and cured in the field for 39 weeks. Cuttings of two cottonwood (Populus deltoides Bartr. ex Marsh) clones were planted in a field soil (Quincy loamy fine sand) that was mixed (incorporated) or mulched (placed on top the soil) with raw or composted sludge mixtures at application rates of 0,45,90, 135 and 180 Mg/ha. The plants were grown in a plastic house for nine weeks. Electrical conductivity (EC), cation exchange capacity (CEC), soluble Cl and extractable Na in soil amended with 180 Mg/ha of compost were 37, 22, 197 and 138 percent higher, respectively, than those of soil amended with the raw sludge mixture at the same rate. Bulk density of amended soil decreased, whereas soil aeration and water-holding capacity increased as sludge application rate increased. After nine weeks, raw or composted sludge applied at a rate of 135 Mg/ha, whether used as a mulch or incorporated, improved cottonwood plant height by 40 percent and stem diameter by 20 percent compared to plants grown in nonamended, nonmulched (control) soil. These results indicate that the pulp and paper sludge mixtures, whether raw or composted, improved soil characteristics and aided establishment of cottonwood cuttings.  相似文献   

4.
The objective of the present study was to evaluate the plant phosphorus (P) availability of products derived from new P‐recovery technologies deployed in wastewater treatment systems against sewage sludge and untreated sewage sludge ashes. Eight P sources were evaluated in a six‐week pot experiment with spring barley (Hordeum vulgare L.) and a soil incubation experiment with anaerobically digested and dewatered sewage sludge (Sludge), sewage sludge ash (Ash), thermochemically treated sewage sludge ash (TrAsh), struvite (Struv), concentrate (Conc), and centrifuged concentrate (Prec) from evaporated reject water, with triple super phosphate (TSP), and composted organic household waste (Comp) as references. All sludge‐related materials except struvite came from the same wastewater treatment plant in Denmark. The apparent plant P use efficiency (PUE) of the treatments in the pot experiments was in the following order: Prec (17.0%) > TSP (12.8%) ≥ Conc (12.7%) > Sludge (8.8%) ≥ TrAsh (6.9%) ≥ Struv (6.0%) ≥ Comp (5.8%) > Ash (3.4%). The water‐extractable P (WEP) in the incubation experiment largely supported this order and there was a strong correlation between WEP in the incubation experiment and plant P uptake in the pot experiment. Overall, the results of this study demonstrate that it should not automatically be assumed that products recovered with new treatment technologies for P recovery are more effective P fertilizers than the sewage sludge from which they originate. Furthermore, these results indicate that the measurement of water‐extractable P after soil incubation could be a suitable proxy for plant P availability.  相似文献   

5.
A field experiment was carried out to evaluate the effectiveness of mycorrhizal inoculation with three arbuscular mycorrhizal (AM) fungi (Glomus intraradices Schenck & Smith, Glomus deserticola (Trappe, Bloss. & Menge), and Glomus mosseae (Nicol & Gerd.) Gerd. & Trappe) and the addition of composted sewage sludge (SS) with respect to the establishment of Retama sphaerocarpa L. seedlings, in a semiarid Mediterranean area. Associated changes in soil chemical (nutrient content and labile carbon fractions), biochemical (enzyme activities), and physical (aggregate stability) parameters were observed. Six months after planting, both the addition of composted SS and the mycorrhizal‐inoculation treatments had increased total N content, available‐P content, and aggregate stability of the soil. Values of water‐soluble C and water‐soluble carbohydrates were increased only in the mycorrhizal‐inoculation treatments. Rhizosphere soil from the mycorrhizal‐inoculation treatments had significantly higher enzyme activities (dehydrogenase, protease‐BAA, acid phosphatase, and β‐glucosidase) than the control soil. In the short‐term, mycorrhizal inoculation with AM fungi was the most effective treatment for enhancement of shoot biomass, particularly with G. mosseae (about 146% higher with respect to control plants). The addition of the composted SS alone was sufficient to restore soil structural stability but was not effective with respect to improving the performance of R. sphaerocarpa plants.  相似文献   

6.
In dairy farming, recirculation and continuous use of nutrients are necessary for sustainable nutrient management in both the short- and long-term. When managed effectively, nutrient recycling can improve soil fertility. On the other hand, if applied nutrients are in excess of the soil’s nutrient holding capacity, nutrients can enter surface and ground water bodies resulting in eutrophication. Phosphorus (P) characterisation in manure, pond sludge and crust, in terms of plant availability, is the first step to sustainably manage nutrients within dairy farms. In this study, pond sludge and crust were characterised for P using a sequential fractionation method. Pond sludge and crust contained significant amounts of labile P. Water extractable P (H2O-P) in primary anaerobic pond and secondary facultative pond sludges was found to be about 8 to 13 times higher than the amount found in the surface soil (0–10 cm) of a grazing paddock. Similarly, sodium bicarbonate extractable P (NaHCO3-P) in the two types of sludges was found to be about 6 times higher than in the soil. The relatively higher labile P (H2O-P and NaHCO3-P) in sludge compared to soil indicates that the sludge can be utilised as a P fertilizer on grazing pasture. In contrast, lower H2O-P compared to that of raw manure indicates that the use of sludge and crust instead of raw manure can reduce the possibility of P loss by surface runoff and leaching. Hence, it is preferable to use pond sludge and crust as fertiliser instead of raw manure.  相似文献   

7.
Tomato plants (Lycopersicum esculentum Mill, ‘Red Cherry Small’), grown in 15 cm diameter plastic pots with a standard greenhouse medium (1:1:1, by volume, soil:peat:sand) were irrigated for 15 weeks with liquid sewage sludge containing a liquid cationic conditioner (Petroset SB, Phillips Petroleum Company, Bartlesville, Oklahoma) to determine the effect of the conditioner on Cd and Zn availability. Half of the plants received 50 ml week?1 liquid digested sludge with no conditioner and half of the plants received 50 ml week?1 sludge containing 0.25 ml conditioner (200:1, by volume, sludge:conditioner). Plant height was measured weekly. Plants were harvested 3, 6, 9, 12, and 15 weeks after sludge treatments began and separated into roots, shoots, and fruits for dry weight determination and Cd and Zn analyses. Soil and sludge crusts were sampled at the same times and analyzed for extractable concentrations of Cd and Zn. Dry weights of plants grown with conditioned sludge were similar to those grown with nonconditioned sludge. Plants with conditioner flowered and fruited one and two weeks earlier, respectively, than plants without conditioned. Six weeks after treatments began, when the plants had grown to their greatest height, Cd concentrations in sludge crusts, soil, and roots receiving conditioner were 2.0, 1.5, and 2.1 times greater, respectively, than crusts, soil and roots not receiving conditioner. After the six weeks sampling time, Cd concentrations in crusts, soil, and roots receiving conditioned sludge were similar to those in crusts, soil, and roots receiving nonconditioned sludge. At the third-week sampling time, shoots of plants grown with conditioner had 2.6 times more Cd than shoots of plants grown without conditioner. Cadmium concentrations in shoots from both treatments were similar at later sampling dates. Cadmium content of fruits was the same for both treatments all sampling times. Zinc content of roots, shoots, fruits soil, and sludge crusts was no affected by the conditioner. Results showed that a cationic conditioner, added to sludge, increased the availability of Cd, but not of zn, for tomato plants until maximum height was reached.  相似文献   

8.
Abstract. Over the last three decades there has been a great increase in the production of waste from urban, industrial and agricultural activity that could be recycled as a source of plant nutrients, and used to enhance soil quality. The use of these materials could partially offset the need for mineral fertilizers, giving both economic and environmental benefits. An incubation experiment was carried out using different organic waste materials applied to a Cambic Arenosol. Air-dried soil was mixed with increasing amounts of composted solid municipal waste, secondary pulp-mill sludge, hornmeal, poultry manure, solid phase from pig slurry, and composted pig manure, resulting in applications equivalent to 0, 40, 80, 120, 160 and 200 kg ha−1 of Kjeldahl nitrogen. The samples were incubated for 244 days under a controlled environment of 24 °C and 60% water holding capacity of the soil. The increasing amounts of waste applied always led to a greater amount of potentially available nitrogen present in the soil/waste mixture. Based on the proportion of their active N fraction, wastes were ranked: poultry manure>hornmeal>solid phase from pig slurry>composted pig manure>secondary pulp-mill sludge>composted municipal solid waste. The results were well described by a one-pool exponential mineralization model, and mineral N formation was proportional to the quantity of waste applied. Of the wastes tested, those from animal sources showed greater nitrogen mineralisation. Nitrification was rapid, and concentrations of ammonium nitrogen remained relatively small.  相似文献   

9.
Composting and thermal drying are amongst the most commonly used post-digestion processes for allowing sanitation and biological stabilization of sewage sludge from municipal treatment plants, and making it suitable as soil conditioner for use in agriculture. To assess the impact of sludge-derived materials on soil microbial properties, fresh (LAF), composted (LAC) and thermally dried (LAT) sludge fractions, each resulting from a different post-treatment process of a same aerobically digested sewage sludge, were added at 1% (w/w) application rate on two contrasting (a loam and a loamy sand) soils and incubated under laboratory conditions for 28 days. Soil respiration, microbial ATP content, hydrolytic activities and arginine ammonification rate were monitored throughout the incubation period. Results showed that soil biochemical variables, including the metabolic quotient (qCO2), were markedly stimulated after sludge application, and the magnitude of this stimulatory effect was dependent on sludge type (precisely LAT > LAF > LAC), but not on soil type. This effect was related to the content of stable organic matter, which was lower in LAT. Genetic fingerprinting by PCR–DGGE revealed that compositional shifts of soil bacterial and, at greater extent, actinobacterial communities were responsive to the amendment with a differing sludge fraction. The observed time-dependent changes in the DGGE profiles of amended soils reflected the microbial turnover dependent on the sludge nutrient input, whereas no indications of adverse effects of sludge-borne contaminants were noted. Our findings indicate that composting rather thermal drying can represent a more appropriate post-digestion process to make sewage sludge suitable for use as soil conditioner in agriculture.  相似文献   

10.
Abstract

The combined action of a soil conditioner and a controlled‐release fertilizer was followed by conducting soil column leaching and tomato growth experiments. The change in soil water‐holding capacitiy and the release of potassium sulfate (K2SO4) from conventional and controlled‐release forms was evaluated using leaching experiments in soil columns. Tomato growth was followed by the comparison of biomass yields on a dry matter basis with experiments where different combinations of controlled‐release or conventional fertilizer rates and soil conditioner applications. It was demonstrated that the combined usage of controlled‐release fertilizers and soil conditioners increased tomato yield and enhanced the nutritional status of the tomato plants in comparison to conventional fertilizer materials.  相似文献   

11.
A sandy soil was amended with different types of sewage sludge (digested, dried, and composted) and pig slurry. The composted sludges displayed higher organic‐matter stability (39–45%) than only digested sludge (26–39%) or digested + dried sludge (23–32%). The microbial biomass of the dried sludge was undetectable. Digested and composted sludges and pig slurry displayed microbial biomasses (12492–13887 µg g?1, 1221–2050 µg g?1, and 5511 µg g?1, respectively) greater than the soil (108 µg g?1). The wastes were applied at seven doses, ranging from 10 to 900 g kg?1. Soils were incubated for 28 days. Substrate‐induced respiration (SIR) was measured for 12 consecutive hours on day 1 and on day 28. The results showed that SIR increased with the dose of organic amendment. However, SIR decreased when moderate doses of pig slurry or high doses of digested + dried sludge were tested. The possibility of using this inhibition as an ecotoxicological indicator is discussed.  相似文献   

12.
In order to promote the transformation of a burnt Mediterranean forest area into a dehesa system, 10 t ha−1 of dry matter of the same sewage sludge in three different forms: fresh, composted and thermally‐dried, were added superficially to field plots of loam and sandy soils located on a 16 per cent slope. This application is equivalent to 13ċ8 t ha−1 of composted sludge, 50 t ha−1 of fresh sludge and 11ċ3 t ha−1 of thermally‐dried sludge. The surface addition of a single application of thermally‐dried sludge resulted in a decrease in runoff and erosion in both kinds of soil. Runoff in thermally‐dried sludge plots was lower than in the control treatment (32 per cent for the loam soil and 26 per cent for the sandy soil). The addition of any type of sludge to both soil types also reduces sediment production. Significant differences between the control and sludge treatments indicate that the rapid development of plant cover and the direct protective effect of sludge on the soil are the main agents that influence soil erosion rates. Results suggest that the surface application of thermally‐dried sludge is the most efficient way to enhance soil infiltration. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

13.
Mine‐soil treatment using stabilized manure rapidly sequesters large quantities of organic carbon and nutrients. However, the nutrient‐rich soil conditions may become highly conducive for production and emission of N2O. We examined this possibility in a Pennsylvania coal mine restored using poultry manure stabilized in two forms: composted (Comp) or mixed with paper mill sludge (Man + PMS) at C/N ratios of 14, 21, and 28 and compared those with the emissions from conventionally treated soil. The mine soil was extremely well drained with 59% coarse fragments. Soil–atmosphere exchange of N2O and CO2 was determined using a sampling campaign of ten measurements between 16 June and 14 September 2009 (90 days) and 13 measurements between 28 June and 9 November 2010 (134 days) using static vented chambers at ambient and increased moisture (water added) content. Potential denitrification was determined in a laboratory incubation experiment. While non‐amended mine soil did not have a measurable potential for denitrifying activity, the manure‐based amendments introduced the potential. Soil water filled pore space was less than 60% on most sampling days in both ambient and water‐added plots. Daily N2O‐N emissions ranged between 40 and 70 g N ha−1 with cumulative emissions of 2–4 kg N ha−1 from non‐amended, lime and fertilizer (L + F) and Comp, and 3–10 kg N ha−1 from Man + PMS treatments. The maximum emission obtained from Man + PMS represented <1% loss of applied N. Although stabilized manure‐treated soil exhibits the potential for N2O production, the emission is limited when soils are excessively well drained and reducing conditions rarely develop. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

14.
Abstract

More than 90% of the nitrogen (N) in soils is bond as organic N compounds. The available N can be estimated on the mineral N released during time‐consuming incubations of soil. Several chemical methods have been developed as substitutes for incubations. On the other hand, there has been an increase in waste production. Residues could potentially offset the need for mineral fertilizers, being both an economic and environmental benefit. Thus, the development of a routine method for prediction of N supply both from soil organic matter (SOM) and the application of organic residues is of great interest. An incubation experiment was performed in a Cambic Arenosol to evaluate different chemical methods. Air‐dried soil was mixed with increasing amounts of composted solid municipal waste, secondary pulp‐mill sludge, hornmeal, poultry manure, the solid phase from pig slurry, and composted pig manure. Samples were incubated for 244 days under a controlled environment. Among the chemical extractants studied, hot 2 M potassium chloride (KCl) and hot 0.01 M calcium chloride (CaCl2) showed promise in indicating values of N0 (potentially available nitrogen), and these simple methods are suitable for use in routine laboratory conditions.  相似文献   

15.
华蓥市山区典型林分水源涵养功能评价   总被引:2,自引:1,他引:1  
为研究南方丘陵山区典型人工林的生长现状和涵养水源能力,选取华蓥市6种林分作为研究对象,通过测定林下枯落物层和土壤层特征,分析比较不同林地枯落物和土壤的持水能力,对林地水源涵养能力进行评价。结果表明:杉木纯林(近自然经营)枯落物现存蓄积量最大,枯落物持水能力排序为杉木纯林(近自然经营)杉木纯林马尾松—檵木混交林(近自然经营)杉木—响叶杨混交林柏木纯林马尾松—杉木混交林;杉木纯林的土壤层总孔隙度、毛管孔隙度、有效持水量均为最优,分别达到67.67%,60.39%,138.11 t/hm~2;6种林地土壤有效持水量大小顺序为杉木纯林杉木纯林(近自然经营)马尾松—杉木混交林杉木—响叶杨混交林柏木纯林马尾松—檵木混交林(近自然经营);综合枯落物层和土壤层持水能力可知,杉木纯林(近自然经营)的水源涵养能力最强,为309.77 t/hm~2,马尾松—杉木混交林最弱。  相似文献   

16.
Hydraulic properties, specifically the water holding capacity of soils, play a key role in the ability of soils to sustain plant growth. Additions of hydrophilic polymers (superabsorbents) can improve the water holding capacity of sandy soils. This has led to practical applications of these materials particularly in arid regions and countries, where water is the limiting factor for plant production. The objectives of this study are to investigate how effective hydraulic properties of polymer‐soil mixtures are affected by addition of absorbents in different concentrations. Novel aspects are the investigation of aging under repeated wetting–drying‐cycles over an appreciable time in the field and a systematic investigation of the salt influence on the water uptake of polymers. We added the polymer Super AB, A‐200 (Iran Polymer Institute), to dune sand in ratios of 0.3%, 0.6%, and 1% w/w. We found that the effective water retention characteristics of the soil–absorbent mixtures were improved with respect to plant‐available water compared to the pure sand, and the improvement was related to the respective amount of absorbent in the mixture. The plant available water content (PAW) increased from 0.005 for the untreated sand to 0.06, 0.20, and 0.28 g g?1, respectively, for the sand with the three polymer additions. Due to aging of the polymers, PAW decreased after 6 months of cyclic drying and wetting to about half of the value immediately after the initial treatment. We attribute this to the effect of salts. This is corroborated by the results from water uptake experiments by the pure polymers. Repeated cycles of water uptake showed that salts in the water greatly reduced the uptake capacity of the polymers after few cycles. The effect was strong for bivalent cations and less pronounced for monovalent cations.  相似文献   

17.
在红壤自然状况下,模拟了施肥沟,对红壤不同污泥施肥处理的N素释放特性进行了研究。试验结果表明,干污泥配比在10%~20%时,碱解氮、铵态氮和硝态氮累计释放量分别为:25.71%~33.48%,9.57%~14.85%和4.08%~7.65%。堆肥污泥配比在20%~33%时,其累计释放量分别为13.55%~15.65%,2.03%~4.23%和3.11%~5.37%。干污泥处理的释放量大于堆肥污泥处理的释放量,释放过程变化较堆肥污泥剧烈,铵态氮和硝态氮均有明显峰值,铵态氮最大含量532.98±10 mg/kg,释放量最大达10.95%;硝态氮含量最大为149.2±14 mg/kg,释放量最大时为3.32%。无论是从氮的肥效角度,还是氮释放的环境风险角度考虑,污泥堆肥处理后施肥方式均优于干污泥处理施肥方式。  相似文献   

18.
Abstract

A lime‐stabilized sewage sludge compost was used as a surface amendment to improve the soil and nutritional status of a number of established pear cultivars grown on an acidic, low ferility soil site. Leaf Ca status was significantly increased while trace metals were not elevated and in most cases decreased by sludge compost over the course of the study. Soil chemical properties were modified in a manner similar to liming. Addition of sludge composts, particularly low metal containing materials, appears to represent an acceptable aid in renovating established pear orchards located on poor soil sites. Leaf, fruit flesh or peel Cd were not significantly effected by the compost addition. The compost added twice the recommended level of available N the first year and sub‐optimum N the following two years. Leaf N, although significantly increased in the composted versus non‐composted controls, was below sufficiency levels by the third year after addition. This indicates that compost cannot fully supply required N from a one time application even over the short term.  相似文献   

19.
[目的]揭示污泥堆肥施用后土壤单位有机碳矿化及温度敏感性(Q10)对于市政污泥资源化利用和土壤碳库稳定性的主控因素,并进而为市政污泥处理及土壤有机碳固持提供理论支撑。[方法]以黄土丘陵区退化草地土壤为研究对象,测定了不同污泥堆肥添加比例(0,2.0%,5.0%,10.0%,15.0%,20.0%)和培养温度(15℃,25℃和35℃)下土壤有机碳矿化速率,探讨了污泥堆肥添加对土壤有机碳矿化特征和Q10的影响。[结果](1)与CK相比,不同污泥堆肥添加在培养初期土壤单位有机碳矿化速率显著增加(p<0.01),之后迅速下降直至趋于稳定;而施用污泥处理组的土壤单位累积矿化量是CK的1.6~4.2倍,在施用比例达到10.0%~20.0%时其有机碳矿化速率与累积矿化量均差异不显著。(2)运用一级动力学方程,拟合不同温度不同污泥添加土壤单位有机碳矿化动态均达到较好效果(R2>0.95),潜在矿化势(C0)值在6.92~39.60 mg C/g差异显著(p<0.05),土壤有机碳矿化速率常数(k)...  相似文献   

20.
张益      林毅雁  张杰铭  贾国栋      樊登星      余新晓     《水土保持研究》2023,30(4):160-168
[目的]研究枯落物和土壤层水文功能,从而明晰北京山区不同植被的水源涵养能力,可为当地植被建设提供借鉴。[方法]使用室内浸泡法、环刀法、定水头法等对北京山区不同植被的枯落物与土壤层水文功能进行了定量分析,并通过相关性分析明确了有机碳与土壤层水文功能之间的关系。[结果](1)枯落物最大持水率、最大拦蓄率、有效拦蓄率为侧柏(Platycladus orientalis)×灌木混交林>五角枫(Acer elegantulum)纯林>五角枫×侧柏混交林>侧柏纯林。最大持水量、最大拦蓄量、有效拦蓄量均为五角枫纯林>侧柏×灌木混交林>五角枫×侧柏混交林>侧柏纯林,且均为半分解层大于未分解层。(2)土壤饱和持水量和毛管持水量排序为侧柏纯林>五角枫纯林>侧柏×灌木混交林>五角枫×侧柏混交林。土壤非毛管持水量大小排序为五角枫×侧柏混交林>五角枫纯林>侧柏×灌木混交林>侧柏纯林。土壤饱和导水率沿剖面向下逐渐减小,平均饱和导水率最大的植被类型为侧柏×灌木混交林。(3)土壤有机碳含量表现为沿剖面向下逐渐减小,且土壤有机碳含量与容重、总孔隙度...  相似文献   

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