Options for the Treatment and Management of Municipal Landfill Leachate: Common and Specific Issues     

Ana‐Maria Schiopu  Maria Gavrilescu 《洁净——土壤、空气、水》2010,38(12):1101-1110

This paper aims to explore information from the literature for emphasizing the state‐of‐the art and progress in landfill leachate generation, fate and migration, and treatment. Leachate composition is discussed in terms of types of waste disposed and the processes occurring within landfill. The focus is also on potential pathways of environmental contamination by leachate, which may increase environmental and human health risk. The analysis addresses the opportunity and support for decision making concerning alternatives for leachate management and treatment. Advantages and limitations of treatment methods and processes are discussed considering leachate transfer, physico‐chemical methods, biodegradation, and combined methods.  相似文献   

Gravity data as a tool for landfill study     

João B. C. Silva  Wlamir A. Teixeira  Valéria C. F. Barbosa 《Environmental Geology》2009,57(4):749-757

This paper shows the potential of gravity data to map a buried landfill bottom topography. To this end, a gravity inversion method is presented for estimating the landfill’s bottom depths at discrete points assuming a decrease of the density contrast with depth according to a hyperbolic law. The method’s efficiency was tested using synthetic data from simulated waste landfills, producing estimated bottom topographies very close to the true ones. The method’s potentiality has been further evaluated in applying it to the gravity data from the abandoned Thomas Farm Landfill site, Indiana, USA, whose bottom topography is known. The estimated topography showed close agreement with the known Thomas Farm Landfill’s bottom topography.  相似文献   

气相色谱法测定水中丙烯酰胺   总被引：2，自引：0，他引：2       下载免费PDF全文

张宗祥  杨文武  陈军 《江苏地质》2009,33(2):196-198

采用溴化衍生-气相色谱法测定水中的丙烯酰胺,方法检测限为0．02μg／L,平均加标回收率为99．1％～104．5％,相对标准偏差为0．8％～2．6％,方法实用准确。  相似文献   

Improving the Quality of Municipal Solid Waste Compost by Using Expanded Perlite and Natural Zeolite     

N. Gamze Turan  Osman Nuri Ergun 《洁净——土壤、空气、水》2008,36(3):330-334

The scope of this study was to investigate the effects of natural zeolite and expanded perlite on the quality of municipal solid waste compost. Various ratios of the materials were added as supplements to the organic fraction of municipal solid waste. These applications were periodically compared with an untreated control process. The results obtained from experimental studies clearly showed that municipal solid waste collected from the metropolitan city center of Samsun, Turkey could not be composted without any additions due to the very high moisture content, which reached up to 75–80%. In the untreated control process, thermophilic temperatures were not supported during the composting. In this system, ammonia and other odors became a problem because of the high pH levels, and the electrical conductivity was too high for aged compost. However, the addition of natural zeolite and expanded perlite had a positive affect on the quality of the final compost. Natural zeolite trapped ammonium and reduced nitrogen losses from the compost. Expanded perlite held excess moisture and supported improved aeration. The results also indicated that the use of natural zeolite together with expanded perlite in municipal solid waste composting processes produced mature and stable compost.  相似文献   

Adsorption of Zinc using Tea Factory Waste: Kinetics,Equilibrium and Thermodynamics     

Kailas L. Wasewar  Mohammad Atif  Basheshwar Prasad  Indra Mani Mishra 《洁净——土壤、空气、水》2008,36(3):320-329

In India, the annual production of tea is ca. 857,000 tonnes, which is 27.4% of the total world production. The amount of tea factory waste (TFW) produced per annum after processing is ca. 190,400 tonnes. TFW can be used as a low cost adsorbent for the removal of toxic metals from the aqueous phase. An investigation was carried out to study the feasibility of the use of TFW as an adsorbent for the removal of the heavy metal, zinc. Equilibrium, kinetic and thermodynamic studies were reported. The straight line plot of log (q_e–q) versus time t for the adsorption of zinc shows the validity of the Lagergren equation. The various steps involved in adsorbate transport from the solution to the surface of the adsorbent particles were dealt with by using a Weber‐Morris plot, q_e versus t^0.5 for the TFW. The rate controlling parameters, k_id,1 and k_id,2, were determined and it was found that the macro‐pore diffusion rate was much larger than micro‐pore diffusion rate. A batch sorption model, which assumes the pseudo‐second‐order mechanism, was used to predict the rate constant of sorption, the equilibrium sorption capacity and the initial sorption rate with the effect of initial zinc (II) ion concentration. Equilibrium data obtained from the experiments were analyzed with various isotherms, i. e., Freundlich, Langmuir, Redlich‐Peterson and Tempkin. The adsorption equilibrium was reached in 30 min and the adsorption data fitted well to all models. The maximum adsorption capacity of TFW for zinc (II) ions was determined to be 14.2 mg/g. The capacity of adsorption on Zn(II) increased with increasing temperatures and pH. The maximum uptake level of zinc was observed at pH of 4.2. The various thermodynamic parameters, i. e., ΔG°, ΔH° and ΔS°, were estimated. The thermodynamics of the zinc ion/TFW system indicated a spontaneous, endothermic and random nature of the process. The results showed that the TFW, which has low economical value, is a suitable adsorbent for the removal of zinc (II) ions from aqueous solutions.  相似文献   

Mineralogical constraints on the determination of neutralization potential and prediction of acid mine drainage   总被引：4，自引：1，他引：3  

A. D. Paktunc 《Environmental Geology》1999,39(2):103-112

 Acid-base accounting tests, commonly used as a screening tool in acid mine drainage (AMD) predictions, have limitations in (1) measuring with confidence the amount of neutralizers present in samples and (2) affording an interpretation of what the test results mean in terms of predicting the occurrence of acid mine drainage. Aside from the analytical difficulties inherent to the conventional methods, a potential source of error in neutralization potential (NP) measurements is the contribution from the dissolution of non-carbonate minerals. Non-carbonate alkalinity measured during static tests may or may not be available to neutralize acidity produced in the field. In order to assess the value-added of extending the NP with the knowledge of mineralogical composition and evaluate potential sources of errors in NP measurements, a suite of samples were examined and characterized in terms of their mineralogical and chemical compositions. The results indicate that although the acid-base accounting tests work well for simple compositions, the tests may result in overestimation or underestimation of NP values for field samples. Mineralogical constraint diagrams relating NP determinations to Ca, Mg and CO₂ concentrations were developed with the purpose to serve as supplementary guides to conventional static tests in identifying possible NP contributions from non-carbonate minerals and checking the quality of the chemical testing results. Mineralogical NP makes it possible to interpret the meaning of NP results and to assess the behaviour of samples over time by predicting the onset of AMD and calculating NP values for individual size fractions. Received: 1 June 1998 · Accepted: 6 October 1998  相似文献   

Atmospheric oxidation of the pyritic waste rock in Maardu, Estonia. 1 field study and modelling     

E. Puura  I. Neretnieks  K. Kirsimäe 《Environmental Geology》1999,39(1):1-19

 A field survey and modelling of the oxidation and carbonate buffering reactions inside the alum-shale-containing waste rock dumps located in Maardu, Estonia, was accomplished. In the slope areas, the shale has been altered at high temperatures due to the spontaneous combustion and the pyritic acidity has been eliminated through migration of SO_x gases out from the dump. In the central parts of the waste rock plateaus, low temperature pyrite oxidation fronts develop towards the dump depth and towards the centres of individual shale lumps. The main secondary phases precipitating in the weathering profile are gypsum, ferric oxyhydroxide, K-jarosite and smectite. The respective field data made it possible to calibrate the two-stage oxygen diffusion model and the characteristic pyrite oxidation rate 0.06–0.08 mol of pyrite reacted per kg of available water (pyrox/H₂O value) was estimated to describe the first tens of years of dump performance. The model is capable to compare different shale disposal strategies that are illustrated with two case scenarios. The buffering of sulphuric acid by Mg-calcite appears to be an incongruent reaction with gypsum precipitating that leads to the build-up of the high Mg/Ca ratio in the leachate. Application of the Mg/Ca method estimates the pyrox/H₂O value in the range of 0.05–0.14 mol/kg. Received: 26 January 1999 · Accepted: 23. February 1999  相似文献   

Engineering geological assessment of a proposed waste disposal site in coastal southwestern Ghana     

E. M. Frempong 《Environmental Geology》1999,37(3):255-260

 An engineering geological investigation has been undertaken of a proposed landfill site in coastal southwestern Ghana which is characterized by torrential rains, high relative humidity, shallow groundwater conditions and almost surrounded by a ridge. The study shows that the site has some desirable characteristics such as availability of suitable soils for the construction of the capping and bottom liners of the landfill, a large tract of land for landfilling operation and its location close to a major highway. However, the groundwater table was shallow and there was a high potential for leachate intrusion into and consequent contamination of nearby groundwater abstraction wells and surface potable water sources thereby constituting serious threat to life. Construction costs could be prohibitive as extensive dewatering and backfilling of vast portions of the project site would be required to enable the provision of a separation between the shallow water table and the bottom of the landfill. Received: 20 January 1998 · Accepted: 26 May 1998  相似文献   

Comparison of 24 h and Long-term pHstat Leaching Tests for Heavy Metal Mobilization from Solid Matrices     

A. Paschke  R. Wennrich  P. Morgenstern 《洁净——土壤、空气、水》1999,27(4):223-229

The dynamic leaching behaviour of environmentally relevant heavy metals makes it difficult to fix a suitable elution time of leaching tests. With ten different solid materials which were characterized by wavelength-dispersive X-ray fluorescence analysis and by the determination of aqua regia soluble amounts of heavy metals we performed 24 h and long-term leaching tests using the pH_stat procedure at pH 4 to be able to compare the resulting acid neutralization capacities (ANC) and heavy metal mobilization. This comparison demonstrates firstly the limitations in predicting the extent of heavy metal release after a longer (geological) time period only from the leached amounts after 24 hours and the ratio of the ANC values measured in the 24 h test and in a long-term experiment, respectively. Secondly, the effect of elution time on the leachability is not uniform but element specific and matrix dependent. Hence, the pH_stat leaching test performed in the usual manner does not seem to be suitable particularly for assessing long-term mobilization of heavy metals under acidic conditions. Additional experiments under variation of shaking frequency and time clearly demonstrate the dominant influence of the first parameter on the resulting ANC and support the necessity of further studies to optimize the pH_stat leaching procedure before the test can be recommended in regulations for environmental protection.  相似文献   

Human-induced sedimentological changes in Manzala Lagoon, Nile Delta, Egypt   总被引：1，自引：0，他引：1  

G. Randazzo  D. J. Stanley  S. I. Di Geronimo  C. Amore 《Environmental Geology》1998,36(3-4):235-258

 The Manzala Lagoon in Egypt's Nile Delta has become a sediment sink of reduced area and depth, with increased contaminant levels. Loss of much-needed fresh to brackish water reserves and decreased fish catches have serious ramifications. Herein, maps of temporal and regional sediment distributions in Manzala incorporate petrological and statistical analyses of 200 surficial and short core samples. These provide baseline information needed to help implement protection measures for this vital wetland. Four periods are considered: 1920s, 1940s, ∼1965, and 1990. Important depositional changes between 1940s and ∼1965 resulted from anthropogenic effects on this quasi-closed lagoon system, including industrial buildup, wetland conversion to agricultural land, and irrigation waterway development. Further modification from ∼1965 to 1990 is associated with closure of the Aswan High Dam, continued construction of waterways that discharge waste water into lagoon margins, and marine incursion into the northern lagoon. If current practices continue, the lagoon could be reduced to about one-third of its present area by 2050 AD. Received: 2 October 1997 · Accepted: 13 January 1998  相似文献