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1.
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   

2.

Purpose

Degraded soils, such as those encountered in areas of mine activities, need to be ameliorated by liming to correct soil acidity and by addition of organic inputs to improve soil properties and fertility.

Materials and methods

Non-amended mine soil and soil amended with stabilized sewage sludge were incubated for 45 days. Soil physicochemical and biological indicators were periodically measured along incubation and other enzyme activities at the end of incubation. In improved soils, a study of plant development in 250-g pots was carried out with three vegetal species: tomato, rye grass and ahipa. Germination and mortality rates, biomass production and photosynthetic pigments were measured.

Results and discussion

Soil incubation with sewage sludge slightly increased soil pH and led to an enhancement of soil electrical conductivity, organic carbon and dehydrogenase activity, especially for the higher doses (5 and 10%). However soil respiration was more promoted with the 2% dose, pointing to a possible toxic effect of the sludge. At the end of incubation, physicochemical and biological properties were in general enhanced. Biomass production was improved in tomato and rye grass by sewage sludge addition (more at the 2% dose), whilst ahipa growth was not affected by sewage sludge treatments. Tomato mortality reached 73% with high sludge doses (10%).

Conclusions

According to this set of parameters, amendment with sewage sludge of a limed acid mine soil would be considered as a good strategy for soil amelioration in view of plant establishment and development.  相似文献   

3.
Soil biochemical properties were measured annually between 1995 and 1999 in soil from an 8-ha site that had received over 1,000 wet tonnes ha–1 undigested sewage sludge, 1–4 years earlier. Basal respiration generally declined with time and was usually greatest in the untreated control area. This trend was attributed to a similar trend in soil moisture content. In contrast, microbial biomass C increased with time and also generally increased with sludge treatment age. Microbial biomass C, and to a lesser extent sulphatase activity, accurately predicted the order of sludge application to the site. This was perceived as a function of time since tillage and pasture establishment, with activities increasing in parallel to the build up of C residues in the soil, and not an effect of sludge or its composition. Except immediately after sludge application, there was no effect on N mineralisation and nitrification. None of the biochemical properties was strongly correlated with heavy metal concentrations. Our results suggest that there was little effect on soil biochemical properties, either adverse or beneficial, of adding raw sewage sludge to this site. Although a companion study showed considerable mobility and plant uptake of heavy metals, this difference could mainly be attributed to a different sampling strategy and the effects of intensive liming of the site.  相似文献   

4.
In many regions worldwide, silvopastoral systems are implemented to enable sustainable land use allowing short, medium, and long‐term economic returns. However, the short‐term production in silvopastoral systems is often limited due to nonappropriate soil‐fertility management. This study evaluated the effects of two doses of lime (0 and 2.5 t CaCO3 ha–1) and three sewage‐sludge treatments (0, 200, and 400 kg total N ha–1 y–1 applied in 2 consecutive years) on soil characteristics (soil pH, soil organic matter [SOM], soil nitrogen, cation‐exchange capacity [CEC]), pasture production, and tree growth in a silvopastoral system of Populus × canadensis Moench in Galicia, northern Spain during 6 years after establishment. Soil pH increased during the experimental period for all treatments, although this effect was more pronounced after lime application. Changes in SOM and soil nitrogen content were not consistent over time, but sewage‐sludge application seemed to result in higher values. Higher CEC was found for treatments with lime and sewage‐sludge application. Following incorporation of lime and sewage sludge, pasture production was significantly enhanced (cumulative pasture production 51.9 t DM ha–1 for Lime/N400 compared to 39.0 t DM ha–1 for No lime/N0). This higher pasture production also affected tree growth due to more severe competition between pasture and tree resulting in slower tree growth. Liming and application of sewage sludge are relevant measures to improve soil fertility and thereby optimizing the overall production of silvopastoral systems. However, it is important not to overintensify pasture production to ensure adequate tree growth.  相似文献   

5.
Organic wastes such as sewage sludge and compost increase the input of carbon and nutrients to the soil. However, sewage sludge-applied heavy metals, and organic pollutants adversely affect soil biochemical properties. Therefore, an incubation experiment lasting 90 days was carried out to evaluate the effect of the addition of two sources of organic C: sewage sludge or composted turf and plant residues to a calcareous soil at three rates (15, 45, and 90 t of dry matter ha–1) on pH, EC, dissolved organic C, humic substances C, organic matter mineralization, microbial biomass C, and metabolic quotient. The mobile fraction of heavy metals (Zn, Cd, Cu, Ni, and Pb) extracted by NH4NO3 was also investigated.The addition of sewage sludge decreased soil pH and increased soil salinity to a greater extent than the addition of compost. Both sewage sludge and compost increased significantly the values of the cumulative C mineralized, dissolved organic C, humic and fulvic acid C, microbial biomass C, and metabolic quotient (qCO2), especially with increasing application rate. Compared to compost, the addition of sewage sludge caused higher increases in the values of these parameters. The values of dissolved organic C, fulvic acid C, microbial biomass C, metabolic quotient, and C/N ratio tended to decrease with time. The soil treated with sewage sludge showed a significant increase in the mobile fractions of Zn, Cd, Cu, and Ni and a significant decrease in the mobile fraction of Pb compared to control. The high application rate of compost resulted in the lowest mobility of Cu, Ni, and Pb. The results suggest that biochemical properties of calcareous soil can be enhanced by both organic wastes. But, the high salinity and extractability of heavy metals, due to the addition of sewage sludge, may limit the application of sewage sludge.  相似文献   

6.
The effect of the dual inoculation with arbuscular mycorrhizal (AM) and saprophytic fungi and a combination of wheat straw and sewage sludge residues were studied by determining their effect on dry weight of tomato and on chemical and biochemical properties of soil. Incubation of organic residue (sewage sludge combined with wheat straw) with saprophytic fungi and plant inoculation with mycorrhizal fungi was essential to study plant growth promotion. Soil application of organic residues increased the dry weight of tomato inoculated with Rhizophagus irregularis. The greatest shoot dry mass was obtained when the organic residues were incubated with Trichoderma harzianum and applied to AM plants. However, the greatest percentage of root length colonized with AM in the presence of the organic residues was obtained with inoculation with Coriolopsis rigida. The relative chlorophyll was greatest in mycorrhizal plants regardless of the presence of either saprophytic fungus. The presence of the saprophytic fungi increased soil pH as the incubation time increased. Soil nitrogen and phosphorus contents and acid phosphatase were stimulated by the addition of organic residues, and contents of N and P. Total N and P content in soil increased when the organic residue was incubated with saprobe fungi, but this effect decreased as the incubation period of the residue with saprobe fungi increased. The same trend was observed for soil β‐glucosidase and fluorescein diacetate activities. The application of organic residues in the presence of AM and saprophytic fungi seems to be an interesting option as a biofertilizer to improve plant growth and biochemical parameters of soils.  相似文献   

7.
施用辐照处理的污水污泥对作物产量和土壤氮的影响   总被引：1，自引：0，他引：1  
A field experiment was conducted to study the feasibility of irradiated and non-irradiated sewage sludge as a fertilizer for the growth of wheat and rice. The irradiated and non-irradiated sewage sludge were applied at rates of 0 (CK), 75, 150, 225 and 300 kg N ha-1 for wheat, and 0 (CK), 112.5, 225, 337.5 and 450 kg N ha-1 for rice, respectively. (NH4)2SO4 at a rate of 150 kg N ha-1 for wheat, and 225 kg N ha-1 for rice were added to the control treatments. Additionally, 20 kg 15N ha-1 in the form of (NH4)2SO4 was added to each treatment for wheat to study the effect of sewage sludge on chemical nitrogen fertilizer recovery. The results showed that the irradiation of sewage sludge by gamma ray at a dosage of 5 kGy increased crop yield by 11%~27% as compared to the non-irradiated treatments. Irradiation stimulated mineralization of organic nitrogen in the sludge and improved seedling growth. It was found that addition of irradiated sludge could reduce the leaching loss of chemical nitrogen fertilizer. Both irradiated and non-irradiated sewage sludge could increase the content of soil total nitrogen. Based on the preliminary results, it was concluded that irradiated sewage sludge could partly substitute for chemical nitrogen fertilizer in crop production.  相似文献   

8.
Tailing ponds pose environmental hazards,such as toxic metals which can contaminate the surroundings through wind and water erosions and leaching.Various chemical and biochemical properties,together with extractable and soluble metals were measured five years after reclamation of a polluted soil affected by former mining activities.This abandoned mine site contains large amounts of Fe-oxyhydroxides,sulphates,and heavy metals.As a consequence,soils remain bare and the soil organic matter content is low(< 3 g kg 1).Marble waste,pig manure and sewage sludge were applied in 2004.Plant cover and richness,and soil chemical,biochemical and biological parameters were analysed five years later.Results showed that all soil biochemical properties as well as vegetation cover and richness were higher in treated soils than in the untreated contaminated plots(control),although organic matter,pH values and extractable metals concentrations were similar among treatments.Soluble cadmium and zinc were lower in the amended plots than in control.As a general pattern,soil amended with pig manure showed higher values of most biochemical properties compared to sewage sludge application,while the doses did not have a great effect,being only significant for β-glucosidase,phosphodiesterase and arylsulfatase.Significant correlations were found between vegetation cover,richness and soil biochemical properties,suggesting a high interdependence between plant colonization and reactivation of biogeochemical cycles during five years.This study confirms the high effectiveness of an initial application of the amendments tested to initialize the recovery of ecosystems in bare mine soils under Mediterranean semiarid conditions.This research also shows the high sensitivity of certain biochemical properties in order to evaluate soil quality and reactivation of nutrients cycles in reclaimed mine soils.  相似文献   

9.
To reclaim a limestone quarry, 200 and 400 Mg/ha of municipal sewage sludge were mixed with an infertile calcareous substrate and spread as mine soil in 1992. Soil samples were taken 1 week later and again after 17 yr of mine soil rehabilitation so as to assess changes in the amount and persistence of soil organic carbon (SOC). Sludge application increased SOC as a function of the sludge rate at both sampling times. Seventeen years after the sludge amendments, the nonhydrolysable carbon was increased in the 400 Mg/ha of sludge treatment. The recalcitrance of SOC was less in sludge‐amended soils than in the control treatment at the initial sampling, but 17 yr later this trend had reversed, showing qualitative changes in soil organic carbon. The CO2‐C production had not differed between treatments, yet the percentage of mineralized SOC was less in the high sludge dose. When the size of active (Cactive) and slow (Cslow) potentially mineralizable C pools was calculated by curve fitting of a double‐exponential equation, the proportion of Cactive was observed to be smaller in the 400 Mg/ha sludge treatment. Soil aggregate stability, represented by the mean weight diameter of water‐stable soil aggregates, was significantly greater in mine soil treated with the high dose of sludge (18.5%) and SOC tended to be concentrated in macro‐aggregates (5–2 mm). Results suggest that SOC content in sludge‐amended plots was preserved due by (i) replacement of the labile organic carbon of sludge by more stable compounds and (ii) protection of SOC in aggregates.  相似文献   

10.
生活污泥对白菜供磷和土壤磷状况的影响   总被引：3，自引：1，他引：2  
采用好气培养和盆栽试验以探明污泥磷的肥效,降低污泥施用导致的土壤磷累积引起的环境风险。结果表明,单施污泥土壤有效磷含量和白菜吸磷量均显著低于施用磷酸一铵和鸡粪处理;施用污泥后有利于增加白菜生长后期土壤磷酸酶的活性和土壤Olsen-P含量。在白菜等产量条件下,单施污泥处理土壤中Olsen-P残留量显著高于污泥与化肥混施处理;在P2O5施用量为902~70 kg/hm2时,污泥堆肥磷的肥效为磷酸一铵的25%左右。  相似文献   

11.
连续施用无害化污泥堆肥对沙质潮土肥力的影响   总被引：2，自引：1，他引：1  
【目的】 研究连续施用无害化污泥堆肥对土壤肥力和环境质量的影响,为无害化污泥资源化利用提供理论依据和技术支撑。 【方法】 通过2013—2015年田间定位试验,每年按照当地农民施肥量在小麦和玉米季分别施用N 225 kg/hm2、P2O5 86 kg/hm2和K2O 113 kg/hm2 (CK) 基础上,施用无害化污泥堆肥15 t/hm2 (W1)、30 t/hm2 (W2) 和45 t/hm2 (W3),共四个处理,每个处理3次重复。小麦、玉米收获后,采集0—20 cm土层样品,测定常规土壤理化性质、重金属含量以及微生物量碳氮 (SMBC、SMBN)。采用内梅罗指数法计算土壤pH、有机质、全氮、有效磷和速效钾分肥力系数IFIi,以及土壤综合肥力指数 (integrated fertility index,IFI)。 【结果】 1)施用污泥堆肥处理IFI在试验的第三年 (2015年) 玉米季达到最大值,与CK相比,W1、W2和W3处理IFI分别显著提升了57.3%、95.2%和127.5% (P < 0.05),说明连续施用污泥堆肥可以有效提高土壤肥力水平,其中W3处理效果最明显。2) SMBC和SMBN含量随污泥堆肥施用时间增加而增加。相同作物同一污泥堆肥施用量处理,第三年 (2015年) 的SMBC和SMBN含量均显著高于第一年 (2013年)。W1、W2和W3处理SMBC含量在2015年小麦季达到最大值,较CK分别显著提高了109.9%、176.2%和216.8% ( P < 0.05);W1、W2和W3处理SMBN含量在2015年玉米季达到最大值,较CK分别显著提高了55.6%、100.5%和162.3% ( P < 0.05)。3)施污泥堆肥处理的土壤和植物籽粒中重金属含量分别低于国家环境质量二级标准 (GB15618—1995) 和国家农产品质量安全规定的限量值。根据土壤肥力分级参考标准 (NY/T 391—2000),2015年玉米季W2和W3处理的土壤肥力已经达到I级,培肥作用显著,但长期大量施用导致的土壤重金属累积风险还需长期监测。 【结论】 施用重金属含量达到国家标准的无害化污泥堆肥,可以在短期内有效提升沙质潮土的土壤肥力质量,改善土壤微生物学特性。本试验条件下,连续施用45 t/hm2污泥堆肥效果最显著,沙质潮土的土壤肥力质量在第三年就达到I级,此时土壤和作物籽粒中重金属含量均低于国家相关标准限值。长期大量施用是否会带来重金属累积还需继续监测。   相似文献   

12.
Continuous cultivation has been known to decrease soil organic matter content. Application of organic matter to cultivated soil is an important practice from the point of view of maintaining an adequate amount of soil organic matter. Soil organic matter content significantly affects soil microbial activity, which is an important index of soil quality. In this study, a field experiment was conducted to examine the long-term effects of different kinds of organic matter in combination with inorganic nitrogen (N) fertilizer on chemical and biological properties of soils. There were seven treatments, namely (1) CK (without fertilization), (2) Chem-N (applying chemical N fertilizer only), (3) Comp (applying compost with the same rate of N as the Chem-N treatment), (4) Comp + l/3 N (applying compost complemented with 33% of the chemical N fertilizer of the Chem-N treatment), (5) Comp + 2/3 N (applying compost complemented with 66% of the chemical N fertilizer of the Chem-N treatment), (6) GM + 1/3 N (applying green manure complemented with 33% of the chemical N fertilizer of the Chem-N treatment) and (7) Peat + 1/3 N (applying peat complemented with 33% of the chemical N fertilizer of the Chem-N treatment). After continuous treatment for 12 years and with cultivation of 24 crops on the same area, soils were sampled for analyses of chemical and biological properties, enzymatic activities and phospholipid fatty acid (PLFA) profiles. The results showed that compared with CK and Chem-N treatments, applications of compost and peat increased soil organic carbon (SOC) content and altered microbial activities and microbial community structure. However, application of green manure for 12 years had no effect on SOC content. Both microbial activities and PLFA profiles were clearly dependent on the characteristics of the applied organic amendments. In summary, a peat application led to the highest increase in SOC content compared to compost and green manure; however, compost-treated soil had a higher microbial population and higher microbial and enzyme activities, while the effects of both green manure and chemical N fertilizer on soil properties were similar.  相似文献   

13.
ABSTRACT

There is a need to improve the way in which crop residues and industrial organic wastes are managed and also to study their potential use in agriculture for improving soil fertility and biological activity. This study evaluated the effects of integrated use of organic (sewage sludge (SS) and rice straw compost (RSC)) and inorganic fertilizers on crop yield, soil enzymes activity, macro- and micro-nutrients availability under rice–wheat cropping system after three consecutive years of cropping in a subtropical semi-arid area. Different combinations of inorganic nitrogen and two doses of organic sources (SS and RSC) were applied to the soil. The results revealed that substitution with 50% N through RSC significantly increased the yield and biochemical properties as compared to inorganic fertilizers (NPK) alone. Micronutrients availability was found increased in treatment having substitution of 50% N through SS @10 t ha?1. All the enzymatic activities viz. dehydrogenase, fluorescein diacetate (FDA), phosphatase, phytase, and urease) were found to be maximum by substitution of 50% N through RSC. Also, a significant positive correlation was found between soil enzymes (dehydrogenase and FDA) and organic carbon as well as crop yield. Thus, the study demonstrated that substitution of 50% inorganic nitrogen through organic sources will be a better alternative for improving soil quality and productivity.  相似文献   

14.
Lai  K. M.  Ye  D. Y.  Wong  J. W. C. 《Water, air, and soil pollution》1999,113(1-4):261-272
Previous studies showed that coal fly ash could stabilize sewage sludge by reducing metal availability, but fly ash may cause an adverse effect on soil microbial activities. Therefore, an experiment was performed to evaluate the effects of amendment of soil with anaerobically digested dewatered sewage sludge, stabilised with alkaline coal fly ash, on soil enzyme activity and the implications for soil nutrient cycling. Sewage sludge was amended with 0, 5, 10, 35 and 50% w/w of fly ash, and then the ash-sludge mixtures were incubated with a sandy soil at 1:1 (v/v). Dehydrogenase activity decreased with an increase in fly ash amendment level and the time of incubation. Soil receiving 5% ash-sludge amendment had a higher dehydrogenase activity than other treatments. Soil receiving 10% ash-sludge mixture had the highest urease activity and in general, urease activity decreased with increasing incubation time. Phosphatase activity was the highest at 5% ash-sludge mixture amended soil and no general trend was observed with time. Water-soluble Zn, Mn and Cu contents were suppressed by the addition of fly ash. The present experiment indicated that addition of 10% ash-sludge mixture should have a positive benefit on the activity of soil microorganisms, N and P nutrient cycling, and reduce the availability of heavy metals.  相似文献   

15.
The aim was to study the influence of soil properties on the leaching of nitrate, phosphate and organic matter (OM) following the application of sewage sludge to contrasting soils. Seventy agricultural soils from different parts of Spain were amended with sewage sludge (50 t dry weight ha−1), and a controlled column study was developed. After 2, 4 and 6 months of incubation, distilled water, equivalent to an autumn rainfall event of 25 l m−2 in Mediterranean environments, was applied and leachates collected and analysed: pH, electrical conductivity (EC), chemical oxygen demand (COD), phosphate and nitrate. The mean values of pH in the leachates after 2, 4 and 6 months were similar and close to the neutrality. The highest concentrations for the rest of the parameters analysed were found after 2 months of incubation and diminished for 4 and 6 months, especially COD. Soil pH and texture were the most relevant soil properties controlling the leaching of the analysed parameters. The OM mineralization seemed to be enhanced at high values of soil pH, thus increasing the nitrate and reducing the COD leaching. However, phosphate levels were reduced at high values of soil pH. In addition, leaching was promoted in sandy soils. Other soil properties influenced phosphate leaching being the equivalent calcium carbonate soil content as the most relevant. Soil organic carbon was negatively related to the EC and nitrate concentration in the leachates but resulting in a weak contribution compared with soil pH and texture. Concerns about nitrate pollution have been confirmed.  相似文献   

16.
The present study was conducted to assess the suitability of sewage-sludge amendment in soil for Triticum aestivum (wheat) by evaluating the heavy-metal accumulation and physiological responses of plants grown at 10, 25, and 50% sewage sludge amendment rate. Sewage sludge amendment modified the physicochemical properties of soil, thus increasing the availability of heavy metals in soil and consequently greater accumulation in plant parts. The chlorophyll contents generally increased after the sewage sludge treatments. Heavy-metal accumulation in the soil after the treatments did not exceed the limits for land application of sewage sludge recommended by the U.S. Environmental Protection Agency. Recycling sewage sludge as fertilizer will generate economical profits. However, the use of sewage sludge amendment in the soil for growing wheat may not be a good option due to risk of contamination of some heavy metals.  相似文献   

17.
Chemical stabilization is a soil remediation technique based on the incorporation of organic and/or inorganic amendments to metal contaminated soil in order to decrease metal bioavailability and improve soil quality. Consequently, the establishment of follow-up monitoring programmes is essential to ensure the long-term effectiveness of chemical stabilization in terms of both metal bioavailability reduction and soil quality improvement. In this study, three doses (20, 40 and 80 t ha−1) of a lime-treated sewage sludge, that meets legal standards regarding metal contents, were added to a metalliferous mine soil and a variety of physicochemical and microbial indicators of soil quality were measured over time (immediately before treatment application and one and six months after such application). Soil CaCl2-extractable and plant metal concentrations were also measured. We carried out a complementary interpretation of soil microbial properties through their grouping within a set of ecosystem attributes of ecological relevance: vigour, organization, stability, suppressiveness and redundancy. Sewage sludge addition led to an increase in soil pH, but this beneficial effect was transient. The addition of sewage sludge had a more pronounced effect on parameters used here to estimate soil vigour (dehydrogenase activity, basal and substrate-induced respiration). On the contrary, the addition of sewage sludge did not significantly alter the composition of soil microbial communities, as reflected by PCR-DGGE data. Chemical stabilization was only partly successful: it did improve soil quality but the expected reduction in soil metal bioavailability (as reflected by the values of CaCl2-extractable metal concentration) was clearly observed only for Cd (not for Pb or Zn); however, SL addition led to a significant reduction in shoot metal concentration for the three metals under study. The assessment of soil quality at the attribute level has proven useful for the interpretation of the effect of chemical stabilization on soil functioning.  相似文献   

18.
A field experiment with cotton was conducted on a well drained,calcareous,clay loamy Typic Xerochreph to investigate the utility of sewage sludge as a partial substitute for fertilizers and the influence of tis application on the basic soil properties and heavy metal concentrations.The experimental design was completely randomized blocks with five treatments replicated four times each.Sewage sludge came from the treatment plant of the municipality of Volos,Central Greece,with the following characteristics:organic matter content 36.6%,pH(H2O1:5)6.89,CaCO3 53.4g kg^-1,total N 265.g kg^-1,ttal P33.5g kg^-1,and total K 968mg kg^-1 soil.Heavy metal concentrations were Cd 5.24,Pb 442,Ni38,Cu 224,Zn1812,and Mn 260mgkg^-1 dry weight,respectively.The soil was high in potassium(K)and poor in available phosphorus(P).The results showed that sewage sludge application increased cotton yield and K and P concentrations in cotton leaves,Soil pH was reduced in the case of higher sewage sludge rate.Electrical conductivity,organic matter content,totalN,and avaiable P were significantly increased.Total concentrations of Zn,Pb,and Cu were slightly increased.DTPA-extractable Zn,Cu,and Mn were also significantly increased.Available forms of all heavy metals,except Cd,were significantly correlated with organic matter content in a positive way and negatively with soil pH.  相似文献   

19.
以上海曲阳水质净化厂污泥堆肥为研究对象,采用盆栽和土柱模拟的方法研究了污泥堆肥土地利用对土壤环境和植物生长的影响。结果表明,污泥堆肥和滩涂土混配后可降低土壤pH值,提高土壤养分含量,增加高羊茅生物量,同时也增加了土壤Ph、Cu和Zn3种重金属元素含量,但各混合土壤中重金属含量均远低于土壤环境质量Ⅱ类标准。另外,污泥堆肥混配土壤基本不存在病原菌扩散的风险;土柱淋溶试验表明,污泥堆肥施用比例为10％时,不会导致地下水NO3-N和重金属含量超过地下水Ⅱ类标准。综上,污泥堆肥施用比例只要控制在10％以内,可安全进行土地利用。  相似文献   

20.
土壤酶对土壤环境质量指示作用的研究进展   总被引：4，自引：1，他引：4  
土壤环境质量是土壤容纳、吸收和降解各种环境污染的能力。各种污染物(农业、工业)进入土壤后,都会对土壤的环境质量造成一定的影响。土壤酶作为土壤中的重要组成部分,是土壤中产生专一生物化学反应的生物催化剂,对土壤环境质量的变化反应迅速,常被用来作为指示土壤环境质量的生物学指标。因此本文综述土壤酶对化肥、农药、污水污泥、城市垃圾和重金属的指示作用,为污染土壤的修复提供理论依据。  相似文献   

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