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1.
The leaching of heavy metals from plant growth medium, admixed with different amounts of compost (prepared from sewage sludge and yard waste) at pH 5, 6 and 7 was determined over a six-month period. Twelve-week old rhododendron cuttings were planted in 2-L containers and rainfall was supplemented with irrigation to supply two centimeters of water per day. Leachates collected over each two to four week period were analyzed for Cd, Cr, Cu, Ni, Pb and Zn using atomic spectrometry. The concentrations of Cd, Cu, Ni and Zn in the leachates increased with increasing proportions of compost in the medium and decreased with increasing time of leaching. Decreasing media pH dramatically increased the concentrations of Cd, Ni and Zn in the leachates, but had no effect on the Cu concentrations. For example, as the proportion of the compost in the pH 5 medium increased from 0 to 100 percent, the concentrations of metals (μg L?1) in the leachates collected during the first two weeks increased from 1 to 33 (Cd), 10 to 123 (Cu), 8 to 113 (Ni) and 300 to 24,000 (Zn). Corresponding increases at pH 7 were 0.4 to 0.8 (Cd), 14 to 141 (Cu), 8 to 28 (Ni) and 100 to 400 (Zn) μg L?1. The concentrations of Cr and Pb in the leachates remained below the detection limits regardless of media pH and amounts of compost. 相似文献
2.
The accumulation of heavy metals (HMs) in soils is the most often cited potential risk of compost application. As the ecological effects of metals are related to mobile fractions rather than to total concentrations in the soil, we measured the total (aqua regia–extractable) HM concentrations, the readily available water‐soluble and the potentially bioavailable LiCl‐extractable fraction of soil HMs in a field experiment after 10 y with total applications of 95, 175, and 255 t ha–1 biowaste compost (fresh matter). Total soil concentrations of Cd, Cr, Cu, Ni, and Pb in the compost treatments were not significantly higher than in the unfertilized control. Total Zn concentrations increased in the treatment with the highest application rate, as expected from the calculation of the Zn load in the composts. In the mobile fractions, as measured in soil saturation extract and LiCl extract, Cd and Pb were not detectable. Concentrations of Cr, Ni, and Zn were in the range published for unpolluted soils in other studies and did not show any differences according to treatment. Easily exchangeable Cu (in LiCl extract) was increased with compost fertilization, most probably due to complexation with low‐molecular organic complexants. Except for Cd and Zn, the results of the mobile HM fractions in the soil were in good agreement with plant HM concentrations. In conclusion, fertilization with high‐quality biowaste compost at such rates and after 10 y of application gives no cause for concern with regard to both total HM concentrations and available HM fractions. 相似文献
3.
This study is aimed at ascertaining the chemical partitioning ofCu, Zn, Pb, Ni, Cr and Cd in sewage sludge and agricultural soils repeatedly amended with sludge. The operationally determined speciation was investigated by using selective five steps sequential extraction method for partitioning these metals into different chemicalforms, likely to be released in solution under various environmental conditions. It provides qualitative evidence regarding the form of the association of metals and indirectly of their bioavailability. It can help to explain the process by which metals are eliminated from sewagesludge and also indicate the impact of the use of sludge on agriculturalsoils, as amendments. Data obtained by extraction procedure showed different metal distribution trend among the fractions in sewage sludgeand sludge-amended soils. Comparison of distribution pattern of metals in sludge and sludge-applied soils shows that there is possible redistribution of metals among the different phases. The sum of the metal content in the fractions compared well with the total metal content in sewage sludge, the ratios averaging 1.02, 1.04, 1.07, 0.94, 1.06, and 1.12 for Cu, Zn, Pb, Ni, Cr, and Cd, respectively. The metal recovery efficiency in sludge-amended soils was found to be: 108±6%, 102±5%, 115±8%, 111±4%, 104±7%and 124±28% for Cu, Zn, Pb, Ni, Cr and Cd, respectively. 相似文献
4.
《Communications in Soil Science and Plant Analysis》2012,43(15-16):1403-1419
Abstract Two composts were tested in eleven different Malus domestica orchards: one was a sewage sludge and bark compost with a low heavy metal content, the other was a municipal solid waste compost with a higher concentration of metals. For six years the zinc (Zn), copper (Cu), nickel (Ni), lead (Pb), cadmium (Cd), and chromium (Cr) content were monitored in the soil, both in ‘total’ and EDTA extractable form, and in leaves and fruits. The resulting data demonstrate clearly that the sewage sludge and bark compost did not cause any significant increase of heavy metal levels in soil and plants; this compost can thus be used to fertilize the soil with no danger either to the environment or to crops. In contrast, the municipal solid waste compost led to a notable accumulation of all the metals examined in the soil and, above all in the case of Pb and Cd, also in the vegetation and the fruits. 相似文献
5.
The goal of this study was to measure the As, Cu, Fe, Pb and Zn contents of soils amended with municipal solid waste (MSW) and MSW-biosolids compost and to determine the long-term transport of these metals to lower soil horizons. Lead, Cu, Cd and Zn contents in the composts were 3–20 times more concentrated in the compost compared to the soil at the Calverton, NY, U.S.A. farm. As a result, Pb, Cd, Cu and Zn were elevated in the upper 5 cm soil layer following compost application and the metal enrichment was proportional to the amount of compost applied (21–62 Mg ha-1). In addition, Pb, As and Cu contents of the non-compost amended Calverton soils were enriched above the tillage depth (20–25 cm). Cu, Pb and As enrichment was attributed to the historical use of sodium arsenite, lead arsenate and copper sulfate insecticides and fungicides. Results of the metal analyses of soil cores collected 16 and 52 months following compost application showed that Cu, Zn and Pb remained confined to the upper 5 cm soil layer. The low water extractable fraction of these metals in MSW and MSW-biosolids compost was a major factor limiting the transport of these metals to lower soil horizons. In contrast, Cd leaching from the upper 0–5 and 5–10 cm soil layers was continuous over the 52 month study period and was attributed primarily to the presence of soluble Cd in phosphate fertilizer initially applied to the Calverton farm soil. 相似文献
6.
肥料重金属含量状况及施肥对土壤和作物重金属富集的影响 总被引：56，自引：5，他引：56
本文对肥料中重金属的含量状况以及施肥对土壤和农作物重金属累积影响的研究进展进行了系统分析和总结。过磷酸钙中锌（Zn）、 铜（Cu）、 镉（Cd）、 铅（Pb）含量高于氮肥、 钾肥和三元复合肥,有机-无机复混肥料中的Pb含量高于其他化肥。有机肥如畜禽粪便、 污泥及其堆肥中的重金属含量高于化肥,猪粪中的Cu、 Zn、 砷（As）、 Cd含量明显高于其他有机废弃物,鸡粪中铬（Cr）含量高;污泥和垃圾堆肥中Pb或汞（Hg）含量高。商品有机肥Zn、 Pb和镍（Ni）含量高于堆肥,Hg含量高于畜禽粪便。多数研究表明,氮磷钾配施与不施肥相比土壤Cd和Pb含量增加,施用有机肥比不施肥提高土壤Cu、 Zn、 Pb、 Cd含量。施用化肥对农作物重金属富集的影响不明确,而施用有机肥可提高作物可食部位Cu、 Zn、 Cd、 Pb 的含量,影响大小与有机肥种类、 用量、 土壤类型和pH以及作物种类等有很大关系。在今后的研究中应着重以下几个方面, 1）典型种植体系下土壤重金属的投入/产出平衡; 2）不同种植体系下长期不同施肥措施对土壤重金属含量、 有效性影响的动态趋势; 3）典型种植体系和施肥措施下土壤对重金属的最高承载年限; 4）现有施肥措施下肥料中重金属的最高限量标准。 相似文献
7.
Christian B. Sekomo Egide Nkuranga Diederik P. L. Rousseau Piet N. L. Lens 《Water, air, and soil pollution》2011,214(1-4):321-333
The Nyabugogo natural wetland (Kigali City, Rwanda) receives all kinds of untreated wastewaters, including those from industrial areas. This study monitored heavy metal concentrations (Cd, Cr, Cu, Pb, and Zn) in all environmental compartments of the swamp: water and sediment, the dominant plant species Cyperus papyrus, and fish (Clarias sp. and Oreochromis sp.) and Oligochaetes. Cr, Cu, and Zn concentrations in the water were generally below the WHO (2008) drinking water standards, whereas Cd and Pb were consistently above these limits. Except Cd, all metal concentrations were below the threshold levels for irrigation. The highest metal accumulation occurred in the sediment with up to 4.2 mg/kg for Cd, 68 mg/kg for Cu, 58.3 mg/kg for Pb, and 188.0 mg/kg for Zn, followed by accumulation in the roots of C. papyrus with up to 4.2 mg/kg for Cd, 45.8 mg/kg for Cr, 29.7 mg/kg for Cu, and 56.1 mg/kg for Pb. Except Cu and Zn, other heavy metal (Cd, Cr, and Pb) concentrations were high in Clarias sp., Oreochromis sp., and Oligochaetes. Therefore, there is a human health concern for people using water and products from the swamp. 相似文献
8.
粉煤灰和钢渣处理多种金属污染的酸性土壤，金属有效性的衰减研究 总被引：4，自引：0，他引：4
The objectives of this work were to determine the potential mineralization of various organic pollutants that are likely found in compostable materials during composting, and to evaluate the participation of the microflora of the thermophilic and maturation composting phases in pollutant mineralization. Four composts were used: a biowaste compost (BioW), a municipal solid waste compost (MSW), a green waste compost (GW) and a co-compost of green waste and sludge (GW+S). In each composting plant, two samples were withdrawn: one in the thermophilic phase (fresh compost) and one in the maturation phase (mature compost) to have the microflora of thermophilic and maturation phases active, respectively. The mineralization of 5 organic pollutants, 3 polycyclic aromatic hydrocarbons (PAHs) (i.e., phenanthrene, fluoranthene and benzo(a)pyrene), 1 herbicide (dicamba) and 1 polychlorinated biphenyl (PCB, congener 52), was measured in a laboratory setting during incubations at 60 ℃ in fresh composts and at 28 ℃ in mature composts. All molecules were 14 C-labeled, which allowed the mineralization of the molecules to be measured by trapping of produced 14CO2 in NaOH. Their volatilization was also measured by trapping molecules on glass wool impregnated with paraffin oil. Mineralization of the organic molecules was only observed when the maturation microflora was present in the mature composts or when it was inoculated into the fresh compost. Phenanthrene mineralization of up to 60% in the fresh GW+S compost was the only exception. Mineralization of PAH decreased when the complexity of the PAH molecules increased. Mineralization of phenanthrene and fluoranthene reached 50%-70% in all mature composts. Benzo(a)pyrene was mineralized (30%) only in the MSW mature compost. Dicamba was moderately mineralized (30%-40%). Finally, no PCB mineralization was detected, but 20% of the PCB had volatilized after 12 d at 60 ℃. No clear difference was observed in the degrading capacity of the different composts, and the major difference was the larger mineralizing capacity of the maturation microflora compared with the thermophilic microflora. 相似文献
9.
In utilizing municipal solid waste (MSW) as fuel for energy production, about 10 percent remains as a noncombustible small size fraction byproduct called refuse derived fuel unders (RDFU). We assessed the feasibility of using RDFU to produce compost for land applications, in the context of acceptable limits for metals. Periodic random samples from two batches of RDFU obtained during composting were analyzed for the heavy metals Cd, Cu, Pb, and Zn, and for the plant nutrients N, P, and K. The heavy metal content (mg/kg, dry weight) in all samples ranged from 1.7-12.7 (Cd), 201-3217 (Cu), 267-5002 (Pb), 344-2079 (Zn). The total variability of these elements within a batch of RDFU compost was high, with relative standard deviations (RSD) ranging from 20-107 percent. Estimates of the number of samples needed to obtain a 10 percent uncertainty in the averages ranged from 5-138, depending on the analyte and the compost batch. Leachability tests showed little leaching of metals in the RDFU compost. The high variability in heavy metal content and the excessive Pb concentrations in this RDFU may limit its use for composting. 相似文献
10.
Appropriate compost standards are being considered in Canada. Five aspects of compost safety and quality are being evaluated; probably the most controversial aspect is the standards for metals in compost. In order to assist in the development of appropriate standards, the authors began an extensive research project in October, 1993 to determine the bioavailability of metals from compost and compost-metal mixtures. Swiss chard was grown in compost-amended soils or compost in a growth room using five treatments of increasing percentages of compost in the media (0, 25 percent, 50 percent, 75 percent, 100 percent compost (v/v)). A Truro loamy sand and a race-track manure-biosolids compost (RTM-biosolids) supplemented with a high metal biosolids were used in a completely randomized design with five replicates. Dry matter yield, metal content in plant tissue, and total metal uptake were evaluated as well as the total and DTPA-extractable metal content in the compost-soil mixes. The results of this and five other experiments conducted by the authors will help determine whether the suggested limits for As, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Se and Zn in composts are appropriate. 相似文献
11.
宝鸡市街尘重金属元素含量及其环境风险分析 总被引：3，自引：0，他引：3
分析了宝鸡市街尘中重金属元素的含量,结果表明:宝鸡市街尘中Cu、Pb、Zn、Cr、Cd、As和Hg的平均含量分别为123.2、408.4、715.1、126.7、5.5、19.8和1.1μg g-1。在工业区、交通区及商业区,除Cr和As略微高于陕西省土壤元素背景值(1.6~2.2倍),其他重金属元素均远远高于陕西省土壤元素背景值(5~64倍)。不同功能分区街尘中重金属元素含量存在显著差异,Hg在交通区含量最高,其他重金属元素均在工业区最高。地累积污染指数法的评价结果表明,宝鸡市街尘中除Cr和As的污染较轻外,其他重金属元素的污染均比较严重,尤其是Cu和Pb在工业区尤为突出。潜在生态风险指数法的评价结果表明,宝鸡市街尘中重金属元素的污染水平和生态危害达到了严重程度,其中,Cr和As属于中等污染,其他重金属元素达到了重度以上污染,Cu、Zn、Cr、As和Pb属于中等潜在生态危害,Hg和Cd达到严重潜在生态危害。 相似文献
12.
《Communications in Soil Science and Plant Analysis》2012,43(4):390-407
The To Lich and Kim Nguu Rivers, laden with untreated waste from industrial sources, serve as sources of water for irrigating vegetable farms. The purposes of this study were to identify the impact of wastewater irrigation on the level of heavy metals in the soils and vegetables and to predict their potential mobility and bioavailability. Soil samples were collected from different distances from the canal. The average concentrations of the heavy metals in the soil were in the order zinc (Zn; 204 mg kg?1) > copper (Cu; 196 mg kg?1) > chromium (Cr; 175 mg kg?1) > lead (Pb; 131 mg kg?1) > nickel (Ni; 60 mg kg?1) > cadmium (Cd; 4 mg kg?1). The concentrations of all heavy metals in the study site were much greater than the background level in that area and exceeded the permissible levels of the Vietnamese standards for Cd, Cu, and Pb. The concentrations of Zn, Ni, and Pb in the surface soil decreased with distance from the canal. The results of selective sequential extraction indicated that dominant fractions were oxide, organic, and residual for Ni, Pb, and Zn; organic and oxide for Cr; oxide for Cd; and organic for Cu. Leaching tests for water and acid indicated that the ratio of leached metal concentration to total metal concentration in the soil decreased in the order of Cd > Ni > Cr > Pb > Cu > Zn and in the order of Cd > Ni > Cr > Zn > Cu > Pb for the ethylenediaminetetraaceitc acid (EDTA) treatment. The EDTA treatment gave greater leachability than other treatments for most metal types. By leaching with water and acid, all heavy metals were fully released from the exchangeable fraction, and some heavy metals were fully released from carbonate and oxide fractions. The concentrations of Cd, Cr, Cu, Ni, Pb, and Zn in the vegetables exceeded the Vietnamese standards. The transfer coefficients for the metals were in the order of Zn > Ni > Cu > Cd = Cr > Pb. 相似文献
13.
长期化肥配施不同有机肥对土壤和玉米中重金属累积的影响 总被引：1，自引：1，他引：0
14.
The objective of this study was to test the suitability of a simple approach to identify the direction from where airborne heavy metals reach the study area as indication of their sources. We examined the distribution of heavy metals in soil profiles and along differently exposed transects. Samples were taken from 10 soils derived from the same parent material along N-, S-, and SE-exposed transects at 0—10, 10—20, and 20—40 cm depth and analyzed for total Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn concentrations. The heavy metal concentrations at 0—10 cm were larger than background concentrations in German arable soils except for Cr (Cd: 0.6—1.8 mg kg—1; Cr: 39—67; Cu: 40—77; Ni: 87—156; Pb: 48—94; Zn: 71—129; Fe: 26—34 g kg—1; Mn: 1.1—2.4). Decreasing Cd, Cu, Mn, and Pb concentrations with increasing soil depth pointed at atmospheric inputs. Aluminum and Ni concentrations increased with soil depth. Those of Fe, Cr, and Zn did not change with depth indicating that inputs at most equalled leaching losses. The Pb accumulation in the surface layer (i.e. the ratio between the Pb concentrations at 0—10 to those at 20—40 cm depth) was most pronounced at N-exposed sites; Pb obviously reached Mount Križna mainly by long-range transport from N where several industrial agglomerations are located. Substantial Cd, Cu, and Mn accumulations at the S- and SE-exposed sites indicated local sources such as mining near to the study area which probably are also the reason for slight Cr and Zn accumulations in the SE-exposed soils. Based on a principal component analysis of the total concentrations in the topsoils four metal groups may be distinguished: 1. Cr, Ni, Zn; 2. Mn, Cd; 3. Pb (positive loading), Cu (negative loading); 4. Al, Fe, indicating common sources and distribution patterns. The results demonstrate that the spatial distribution of soil heavy metal concentrations can be used as indication of the location of pollution sources. 相似文献
15.
S. Garrido G. Martin Del Campo M. V. Esteller R. Vaca J. Lugo 《Water, air, and soil pollution》2005,166(1-4):303-319
The final use that may be given to biosolids that result from the treatment of residual municipal waters depends on their physicochemical and microbiological characteristics. Their organic matter content and wealth of essential elements may allow their use for agricultural fertilization purposes. The objective of this research project was to evaluate the physicochemical interactions between soil treated with biosolids and compost from municipal residual waters, and the nutritional parameters of broad bean seeds (Vicia faba L.). The studied area is located in the central region of the Mexican Republic. The biosolids were treated with aerated static pile composting. The experimental work was performed in the area surrounding the East Toluca Macroplant, where nine 2 × 3 m plots were defined and distributed in a Latin square; 3 plots were used as controls (without conditioning), 3 were conditioned with 4.5 Mg ha?1 of biosolids on a dry base, and 3 were conditioned with the same amount of compost. The parameters determined for biosolids, compost, and soil were: pH, electrical conductivity (EC), organic matter (OM), total nitrogen, available phosphorus, cation exchange capacity (CEC), exchangeable cations (Ca, Mg, Na and K), total and available heavy metals (Cd, Cr, Cu, Ni and Zn); for the plant: height reached, green seeds productivity and yield per treatment (ton ha?1); for the seeds: humidity, ashes, fiber, fats, protein, starch and total and available heavy metals (Cd, Cr, Cu, Ni and Zn). pH was slightly acid in soil treated with biosolids (6.71). OM and CEC did not represent significant differences. Total concentrations of Cr, Zn, Ni and Cu in soil presented significant differences (p < 0.05) between treated soil and the control, Cd was not detected. Cu was the most available metal in soil treated with compost (15.31%), Cd and Cr were not detected. The plants had higher growth rates with biosolids (112.22 cm) and compost (103.73 cm); higher green broad bean productivity and higher seed yield, especially in plots containing biosolids, which had rates three times higher than the control. In regards to broad bean seeds, content of ashes, fiber, fats, protein, starch and heavy metals (Cu, Ni and Zn), there were no significant differences between the treatments. Cd and Cr were not detected. In conclusion, it has been proven that the use of biosolids and compost studied in this broad bean crop do not involve an environmental risk, and thus give way to a solution to the problem of final disposition of biosolids in the region. 相似文献
16.
Environmental damages like forest decline in Northern Slovakia could be a result of long-distance transport of pollutants with the dominating north-west winds. On 10 sites, primarily in the northbound upper slopes of west-east oriented mountain ranges in Northern Slovakia, the extent of the heavy metal contamination in soils along a north-south transect was examined. Oi, Oe, Oa, A, and B horizons were sampled and the total concentrations of Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn were determined. The ranges of heavy metal concentrations in the forest floor were higher than reported for comparable samples from Bavarian soils except for Zn (Cd: 0.65–1.77; Cr: 12–40; Cu: 19–41; Ni: 8–24; Pb: 70–187; Zn: 31–92 mg kg?1), in the mineral soil the concentrations were lower. The depth distribution of the metal concentrations indicated a contamination with Cd, Cr, Cu, Ni, Pb, and Zn. The concentration differences between forest floor and mineral soil tended to be higher at the northern than at the southern sites for Cu, Ni, Pb, and Zn, indicating a long-distance transport from the north. Correlation and principal component analyses of the total metal concentrations revealed three groups: Cu, Pb, and Zn inputs mainly seemed to result from long-distance transport from the north, Cr and Ni inputs additionally from local sources. Cd probably had its origin mainly in local sources. This result was further confirmed by the grouping of the sites when clustered. 相似文献
17.
朝天委陵菜的重金属耐性与吸收性研究 总被引：1，自引：0，他引：1
利用植物生长室水培试验和温室土培盆栽试验的方法,研究了朝天委陵菜在不同浓度Pb水培条件下和Cu、Zn、Pb、Cd复合污染土壤条件下的重金属耐性和吸收性,结果表明,水培条件下随着处理浓度的增加,朝天委陵菜均生长良好,虽高浓度Pb处理下出现植株矮小、叶渐黄、根系变黑等毒害症状,但植株并未死亡,表明在水培条件下朝天委陵菜对Pb具有极强的耐性;在最高浓度3 600μmol/L Pb处理下地上部和根中Pb浓度达到最大值,分别为947 mg/kg和71 053 mg/kg。在温室土培盆栽条件下,朝天委陵菜在外加Cu、Zn、Pb和Cd分别为200、1 000、1 000和5 mg/kg的土壤上较对照生长受到抑制,地上部Cu、Zn、Pb和Cd浓度分别达到741±164、18 248±2 222、1 543±483和29.4±5.2 mg/kg;外加重金属更高时则导致植株死亡。朝天委陵菜对Pb胁迫和Cu、Zn、Pb、Cd复合污染土壤具有较强的耐受性,可作为重金属尤其是Pb污染土壤的修复植物。 相似文献
18.
上海宝山区城市表土重金属累积的空间分布规律 总被引：1，自引：0，他引：1
检测了上海宝山区127个表土样点的重金属含量。宝山区表土Zn、Cr、Cd、Pb、Cu、Ni、Mn的平均含量分别为228.6、127.6、0.56、118.5、55.2、55.7、718.7mg/kg。其中Pb、Zn、Cd的含量分别是上海土壤背景值的5.6、3.0、2.8倍,受污染较明显。宝山区地表的重金属含量呈现出明显的空间分布规律:工业区地表,如吴淞、大场等地,多种重金属污染均很重,Zn、Cr、Cd、Pb、Cu的平均含量分别高达407.6、319.0、0.75、101.2、76.2mg/kg;马路绿地土壤Pb的累积较显著,平均为180.2mg/kg;远郊菜地土壤重金属污染不明显。 相似文献
19.
A controlled environment experiment was conducted to determine the effect of amending soil with various rates of high-Cu compost (0, 20, 40, and 60% compost/soil by volume) on dill (Anethum graveolens L.) and peppermint (Mentha X piperita L.) yields, on fractionation of Cu and Zn in soils, on elemental composition of soil and tissue, and on the essential oils. The compost contained about 2000 mg kg(-)(1) of Cu. Dill yields were greatest in the 20 or 40% treatments, but peppermint yields were greatest in the 20% treatment. Compost additions increased soil pH and electrical conductivity (EC), HNO(3) extractable soil B, Ca, K, Mg, Mn, P, S, Na, and Pb. Additions of high-Cu compost to soil increased tissue P, S, and Na in both crops and Mn, Mo, and Zn in dill but decreased tissue Ca, Cd, and Fe in both crops and Mn, Mo, and Zn in peppermint, increased Cu in all soil fractions including exchangeable, and increased tissue Cu of dill and peppermint as compared to unamended soil. Addition of 60% of high-Cu compost to soil resulted in 760-780 mg kg(-)(1) Cu in the growth medium. Nevertheless, Cu content in both crops reached only 12 mg kg(-)(1) DW in the 60% compost treatment, which is below the toxicity levels for plants and below the upper chronic dietary exposure for animals. The application of high-Cu compost altered chemical composition of dill and peppermint essential oils, but oils were free of Cu, Zn, Cd, Ni, Cr, and Pb. Results from this study suggest that mature composts with concentrations of Cu and Zn of 2008 and 321 mg/kg, respectively, can be used as a soil conditioner without risk for phytotoxicity or risk of increasing the normal range of Cu and Zn in crop tissue. However, the long-term effect of the accumulation of heavy metals in soils following repeated compost applications needs to be carefully considered. 相似文献
20.
Abu Kamal Kristine Wichuk Kathleen Londry Christian Felske 《Compost science & utilization》2017,25(3):178-193
The possibility of using construction and demolition (C&;D) waste wood as a bulking material in biosolids composting was investigated. Potential contaminants in C&;D waste wood include arsenic (As), chromium (Cr), and copper (Cu) from treated wood, and lead (Pb) from paints. Untreated and treated woodchips from C&;D wood were mixed with biosolids, composted using an aerated static pile process, and cured. There were no significant differences between untreated and treated woodchips with respect to composting process, time to stability, or product quality. Composting parameters monitored included moisture content, pH, electrical conductivity, organic matter degradation, fecal coliform levels, and stability by respirometry. Finished compost quality was evaluated in terms of potential toxic elements (PTE) levels. PTE values in treated woodchips (26 ± 35, 29 ± 41, 56 ± 46, and 5 ± 5 µg·g?1 for As, Cr, Cu, and Pb, respectively) were higher and more variable than those in the untreated woodchips (3 ± 3, 17 ± 8, 13 ± 2, and 0.5 ± 0.0 µg·g?1). However, both untreated and treated wood compost products met Canadian Council of Ministers of the Environment Category B values for PTE. In addition, and only molybdenum (Mo) and Cu exceeded Category A thresholds. Biosolids were the most significant contributor of Mo, while Cu contributions came from both biosolids and wood chips; some samples of pressure-treated wood showed concentrations of Cu in the range of 765 to 8,455 µg·g?1. The results of this study suggest that treated wood from C&;D recycling facilities will not significantly degrade the quality of biosolids compost products. 相似文献