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化学方法降低城市污泥的重金属含量及其前景分析 总被引:29,自引:0,他引:29
城市污泥含有丰富的氮、磷、钾和有机质、农用的前景广阔。但其中重金属含量常超标而受到限制。利用化学试剂如酸、有机物、表面活性剂等与污泥中的重金属发生作用、形成溶解性的金属离子或金属-试剂络合物,再通过淋滤,可以剔除污泥中大量的重金属,使其降低到符合农用标准。本文介绍了化学方法去除污泥重金属的原理和效果。分析了影响因素,包括重金属种类、污泥特性、操作方法、剔除时间等,并对该法的应用前景进行了讨论。 相似文献
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城市污泥农用的环境效应及控制标准的发展现状 总被引:10,自引:0,他引:10
由于城市污泥中富含植物生长所需要营养元素和有机质, 城市污泥农用已成为污泥资源化进程中的重要方式之一。近十几年来, 国内外在污泥重金属的形态、生物有效性及其在污泥-土壤-植物系统中的迁移转化规律等方面进行了广泛的研究, 并取得显著进展。同时, 污泥中有机污染物质和病原体的环境效应也越来越受到关注。但是在我国, 污泥农用的环境风险评价的长期性、系统性和田间数据验证还需进一步加强, 为合理制定或修改污泥农用标准积累有效的科学数据和提供可靠的科学依据。本文简述了国内外城市污泥的理化性质、污泥农用环境效应以及我国污泥农用标准的研究现状和进展, 并对污泥农用研究进行了展望, 以期为我国污泥农用的研究和发展提供参考依据。 相似文献
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重庆市城市污泥中的重金属及其农用环境容量 总被引:6,自引:1,他引:6
城市污泥农用的环境风险取决于城市污泥中的污染物含量及土壤理化性质。该文分析了重庆市10个城市污水处理厂污泥中的Cu,Zn,Pb和Cd含量及形态,根据土壤环境容量及氮肥施用量计算了重庆主要旱地土壤的最大施用量和年施用量。结果表明,重庆市城市污泥中的Zn、Cu、Pb和Cd含量分别为362.12~725.32mg/kg,69.84~170.22mg/kg,21.25~107.24mg/kg和1.26~4.25mg/kg。污泥中不稳定态Zn、Cu、Pb和Cd的比例分别为42.89%~44.74%,2.69%~9.45%,0.95%~12.06%和61.05%~79.91%。根据土壤重金属的静态容量,计算出重庆主要旱地土壤紫色土和黄壤城市污泥的一次性最高施用量分别为384.62t/hm2和98.90t/hm2。根据土壤重金属动态容量,以15、20、50为年限,计算出的城市污泥的年施用量,紫色土为66.10,60.91和55.71t/(hm2·a),黄壤为30.32,28.99和27.53t/(hm2·a)。根据作物的需氮量计算城市污泥的年施用量为3.04~6.40t/(hm2·a),该施用量低于根据土壤环境的动态容量计算的施用量,按此用量施用城市污泥更安全。 相似文献
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采用东南景天单种、东南景天与香芋套种对污泥进行植物处理,将植物处理后的污泥作为肥料与上层土壤混合后种植玉米,并设不同的肥料处理来研究对玉米生长的影响。结果表明,利用植物处理后的污泥作为肥料种植玉米,玉米生长良好,且长势和产量明显优于对照和施用化肥的处理,其中单种东南景天处理后的污泥与土壤混合种植的玉米籽粒的产量最高,分别是对照和化肥处理的3.26和2.66倍;利用植物处理后的污泥作为肥料所生产的玉米籽粒中Zn、Cd、Cu、Pb的含量符合国家饲料卫生安全标准,作为饲料是安全的。 相似文献
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厌氧消化污泥化学组成及其环境化学性质 总被引:24,自引:1,他引:24
本文剖析了厌氧消化污泥主要组成分的特征和污泥的农业利用价值。认为厌氧消化污泥含较多的有机质和N、P等养分,且有机态养分中相当部分容易矿化,因此具有很好的肥料价值。污泥中所含的各种重金属是一般土壤的20~40倍,但基本未超过我国污泥农用污染物控制标准。Cd和Zn,在污泥中主要以水溶态、交换态和松结合有机态存在,活性相对较高。此外,污泥也具明显的生物毒性。 相似文献
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城市污泥中有机污染物的研究进展 总被引:18,自引:0,他引:18
综述了城市污泥中有机污染物的研究进展。文章指出,城市污泥含有丰富的N、P、K和有机质,但它通常也含有氯酚(CPs)、氯苯(CBs)、氯苯(CBs)、硝基苯(NBs)、多氯联苯(PCBs)、多氯代二苯并二恶英/呋喃(PCDD/Fs)、邻苯二甲酸酯(PEs)、多环芳烃(PASHs)和有机农药等种类复杂的有机污染物而影响其农业利用。不同城市污泥中有机污染物的种类及其含量不同,与污水的来源、污泥类型及其处理方式等因素有关。堆肥处理可以在一定程度上降低城市污泥中有机污染物的含量,从而达到农业利用的目的。 相似文献
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长江三角洲地区城市污泥对蚯蚓的急性毒性效应 总被引:2,自引:0,他引:2
应用滤纸法和自然土壤法测定了长江三角洲地区城市污泥及其与青紫泥混合后对蚯蚓的急性致死效应及慢性毒性效应。结果表明:滤纸法测定的污泥对蚯蚓的毒性症状出现快且严重,不同污泥对蚯蚓的毒性大小差别较大,致死中浓度(LC50)相对应的污泥与水比值(Rsw-LC50)范围在0.0010~0.0242之间。在供试的城市污泥中,上海贮泥池污泥对蚯蚓的毒性最大,上海脱水污泥5对蚯蚓的毒性最小。自然土壤法测定的污泥与土壤作用后对蚯蚓的毒性结果为:所有处理蚯蚓死亡率均为0,各污泥处理对蚯蚓体重增长率的影响差别不大,个别污泥处理蚯蚓体重增长率比对照处理低,即对蚯蚓的体重有负增长影响。与滤纸法各处理相比,中毒症状较轻微,仅极个别中毒症状较明显。与污泥的水浸液相比,污泥与土壤作用后对蚯蚓的毒性大大降低。 相似文献
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应用气相色谱(GC)和高效液相色谱(HPLC)技术对施用城市污泥盆栽植物后的土壤中的多氯联苯(PCBs)、有机氯农药(OCPs)、菲(PA)和苯并[a]芘(B[a]P)进行了系统分析,探讨不同土壤中有机污染物的含量变化情况.结果表明,不同处理土壤中检出的有机化合物,均以PCBs、OCPs和PA为主.强致癌性化合物苯并[a]芘在土壤中的含量远远低于加拿大和荷兰污染土壤治理标准的目标值(0.1 mg/kg和0.025 mg/kg).PA在土壤中的检出率大大高于苯并[a]芘,但均低于加拿大土壤质量控制标准(0.1 mg,kg),极个别高于荷兰土壤质量控制标准(0.045 mg/kg).城市污泥农用后均会造成土壤不同程度的有机污染物污染,有机污染物污染土壤的程度与污泥的性质、有机化合物的性质和土壤的性质等有关. 相似文献
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再论可持续农业思想的发展及其与中国生态农业的关系 总被引:15,自引:2,他引:15
程序 《中国生态农业学报》2002,10(4):1-5
简述了可持续农业发展思想及作为其指导思想的生态学理论近10余年来的发展动向,用比较研究的方法探讨了中国农业可持续发展既不同于发达国家、也不同于一般发展中国家的独特道路。明确指出中国生态农业是当前推行可持续农业的最现实且有效的途径。 相似文献
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Jose Ramón Rico Hernández Ignacio Gómez-Lucas Jose Navarro-Pedreño Manuel M. Jordán Jaume Bech Victor M. Nieto Asencio Noemi Portell Iñiguez 《Journal of Soils and Sediments》2018,18(6):2172-2178
Purpose
This article analyzed the survival of Escherichia coli, total coliforms, and Salmonella spp. in a soil amended with urban sewage sludge due to its potential use in soil rehabilitation and to the risk of microbial pollution.Materials and methods
The survival of E. coli, total coliforms, and Salmonella spp. was determined in a soil amended with different doses of four different urban sewage sludge based on equivalent nitrogen fertilization of 0, 85, 170, and 340 kg N/ha. After the topsoil/sludge mixtures were made, they were wet to 18% moisture and analyzed for 2 months to determine the presence of bacteria, and then again after 1 year.Results and discussion
The results indicate that the presence of microorganisms was strongly conditioned by the type of biosolid and the dose applied. Soil moisture diminished as the experiment progressed and seemed to play a role in controlling the presence of the bacteria.Conclusions
The initial concentrations of bacteria depend on the sewage sludge treatment. The evolution of E. coli had a similar trend as total coliforms, and Salmonella spp. was absent after 8 weeks although a positive presence was detected in some soils after a year. As a conclusion, long periods of time reduce the risk from the presence of pathogens in soils, and the persistence may be closely related to the treatment of sewage sludge and the initial amount of microorganisms in the sewage sludge.14.
Background and Aims
In soils, the most commonly mentioned hazardous substances are metals. One of the sources of its accumulation is the application of sewage sludge. However, little information is available regarding the estimation of the toxicity of sewage sludge or soil treated with sewage sludge, even by means of a battery of bioassays. In this study an evaluation of a battery of bioassays was carried out for toxicity assessment of sewage sludge and sewage sludge-treated soil. The objectives of this study were a) to compare the sensitivity of the different bioassays for the toxicity determination of sewage sludge contaminated with metals and soil treated with this sewage sludge, b) to elaborate a procedure for the attribution of sewage sludge samples to hazard classes based on the ecotoxicological data, and c) to evaluate the suitability of elutriate bioassays and microbial toxicity tests for the assessment of sewage sludge-treated soil. 相似文献15.
Chemical extractability of heavy metals during and after long-term applications of sewage sludge to soil 总被引:15,自引:0,他引:15
Sequential extractions were used on soils from a long-term experiment treated with either metal-contaminated sewage sludge or inorganic fertilizers between 1942 and 1961. The four extracts employed were CaCl2, NaOH, EDTA and aqua regia. These showed that large increases in the proportions of Pb, Cu, Zn, Ni and Cd in at least one of the first three fractions occurred during the first 10 years of sewage sludge additions. Cr always remained predominantly in the aqua regia-soluble fraction. For 30 years after this, including a period of more than 20 years after application of sludges to the field had ceased, there was very little change in the percentage of each metal extracted by each reagent. Although the ‘residual’ (aqua regia-soluble) and EDTA fractions usually contained the largest amounts of metals in either sludge- or fertilizer-treated soils, there were clear differences between the metals: Pb represented the largest fraction of any metal extracted by EDTA, Cu of any metal extracted by NaOH and Cd of any metal extracted by CaCl2. The same extractions were made of the sewage sludges that were applied to the field, and the distributions of the metals differed from those found in the treated soils. It was particularly apparent that more Pb and Cu was present as the ‘residual’ (aqua regia) fraction in sludges than in the soils. 相似文献
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Miaomiao Cheng Longhua Wu Yujuan Huang Yongming Luo Peter Christie 《Journal of Soils and Sediments》2014,14(6):1123-1135
Purpose
A total of 58 dewatered sludge samples were collected from 58 sewage treatment plants (STPs) geographically located in 31 provincial cities of China; the concentrations of heavy metals and antibiotics were determined to monitor the pollutant levels on a large scale, and the pollutant concentrations in sludge samples from different sources of sewage sludge and different geographical regions were compared.Materials and methods
All the samples were divided into two portions, one of which was air-dried for determination of heavy metals. The other portion was placed in a brown glass bottle and frozen at ?20 °C for antibiotics analysis. Total heavy metals were digested with aqua regia and determined by atomic absorption spectrophotometry (Varian SpectrAA 220FS and Varian SpectrAA 220Z). The antibiotics were extracted with EDTA-sodium phosphate buffer with acetonitrile/Mg(NO3)2-NH3?H2O, v/v, 3:1 and analysed by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) and quantified by the isotope-labelled internal standard method.Results and discussion
In all the sludge samples, zinc was the most abundant metal followed by copper, with relatively low concentrations of chromium, lead, nickel and cadmium. Only 20 % of samples exceeded the Chinese class A values of heavy metal standards for agricultural use (GJ/T309-2009). Sixteen different antibiotics were detected in all the sludge samples, and fluoroquinolones (FQs) and tetracyclines (TCs) were more abundant than sulfonamides (SAs). Concentrations of ∑FQs, ∑TCs and ∑SAs ranged from 1,569 to 23,825 μg kg?1 (mean 8,274 μg kg?1, dry weight), from 592 to 37,895 μg kg?1 (mean 8,326 μg kg?1, dry weight) and from 20.1 to 117 μg kg?1 (mean 55.4 μg kg?1, dry weight), respectively. Tetracyclines (except chlortetracycline) were significantly correlated with zinc and lead. No significant regional trends were observed in the concentrations of heavy metals and antibiotics in sludges.Conclusions
Heavy metal concentrations are not the major factor restricting domestic and mixed flow sludge application, but the antibiotic concentrations in sludges are problematic; regulation of antibiotic use and establishment of standards to ensure safe handling of sludges are needed. 相似文献17.
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W. Tadesse J. W. Shuford R. W. Taylor D. C. Adriano K. S. Sajwan 《Water, air, and soil pollution》1991,55(3-4):397-408
A greenhouse experiment was conducted to evaluate the availability of metals from sewage sludge and inorganic salts, and the effect of pH and soil type on yield and metal (Zn, Cu, Cd and Ni) uptake by wheat (Triticum aestivum L. var. ‘holly’). Soils used in this study were Hartsells sandy loam (fine-loamy, siliceous Thermic Typic Hapludult) and Decatur silty clay loam (Clayey, kaolinitic, Thermic Rhodic Paleudult). Two treatments of sewage sludge containing metals were applied at the rate of 20 and 100 mt ha?1. Inorganic Salts of Zn, Cu, Cd, and Ni were applied (as sulfate salts) at concentrations equivalent to those found in the 20 and 100 mt ha?1 sludge. One treatment consisted of inorganic metals plus sewage at the 20 Mg ha?1 rate. Two soil pH levels, one at field pH (below 6.0) and another pH adjusted between 6.5 and 7.0 were used. Wheat plants were harvested four weeks after germination. Two more subsequent harvests were made at four week intervals. For each harvest, dry matter yield increased as the rate of sludge application increased for both soil types. The soil pH also influenced the dry matter yield. High yield was observed when the pH was adjusted between 6.5 to 7.0 for both soils. An increase in yield was also observed at each subsequent harvest for most of the treatments. Inorganic salt treatments produced lower dry matter yields when compared with the sludge. Both sludge application and metal salts increased plant tissue concentration of Zn, Cu, Cd, and Ni at field pH for both soils. However, increasing the pH of the soil for both sludge and inorganic salt treatments generally decreased the tissue concentration of the above metals. 相似文献
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Bacterial leaching of heavy metals from sewage sludge was studied to assess the potential of agricultural application of the decontaminated sludge. Experiments were conducted in both batch processes (at 28 ?C) and continuous process (at 30 ?C) using a culture of Thiobacillus ferrooxidans and a mixted culture of Thiobacillus ferrooxidans and Thiobacillus thiooxidans. Reagent grade ferrous sulfate, spent ferrous sulfate and pyrite were used as the energy substrates. A first order kinetic model of Cu solubilization was proposed. It was shown that the processes in the continuously stirred tank reactor (CSTR) and the air lift reactor (ALR) with 20% cell recycling were more efficient than the others for metal solubilization due to a relatively large bacterial population. 相似文献