Environmental factors affecting growth of grasses，herbs and woody plants on a sanitary landfill

The present study aims at studying relationships between various environmental factors andplant performance on a completed sanitary landfill. Three sites were chosen for comparison: an on-sitelow landfill gas region with a rich vegetation growth (Site L) , an on-site high landfill gas region with apoor vegetation growth (Site H), an off site control region (Site N) which located close to the GinDrinkers' Bay landfill. In Site H, where the levels of methane and carbon dioxide were higher, growth oftrees, shrubs and climbing plants are adversely affected, but not herbs and grasses. Analysis of correla-tion coefficient indicated that carbon dioxide and methane showed a negative correlation with the growth oftrees and shrubs. In Site H, the higher levels of conductivity, Kjeldah-N, Ammonium-N, and variousheavy metals, such as Mn were also exerted their adverse effect on plant growth. Trees tolerant to land-fill gas , e. g. Acacia confusa . would be a better choice for planting on sanitary landfills , in addition to theuse of shallow-rooted trees. Grasses and herbs are less susceptible to landfill gas due to their shallow-rootsystems. Hydroseeding of grasses would ensure a better plant coverage in areas with a moderate level oflandfill gas. Installation of a ventilation system might be needed for areas with a high level of landfill gas.

Fungal diversity and its mechanism of community shaping in the milieu of sanitary landfill

Land filling is the main method to dispose municipal solid waste in China.During the decomposition of organic waste in landfills,fungi play an important role in organic carbon degradation and nitrogen cycling.However,fungal composition and potential functions in landfill have not yet been characterized.In this study,refuse and leachate samples with different areas and depths were taken from a large sanitary landfill in Beijing to identify fungal communities in landfills.In high-throughput sequencing of ITS region,474 operational taxonomic units(OTUs)were obtained from landfill samples with a cutoff level of 3%and a sequencing depth of 19962.The results indicates that Ascomycota,with the average relative abundance of 84.9%,was the predominant phylum in landfill fungal communities.At the genus level,Family Hypocreaceae unclassified(15.7%),Fusarium(9.9%)and Aspergillus(8.3%)were the most abundant fungi found in the landfill and most of them are of saprotrophic lifestyle,which plays a big role in nutrient cycling in ecosystem.Fungi existed both in landfilled refuse and leachate while both the richness and evenness of fungal communities were higher in the former.In addition,fungal communities in landfilled refuse presented geographic variances,which could be partly attributed to physical habitat properties(pH,dissolved organic carbon,volatile solid,NH_(4)^(+),NO_(2)^(−)and NO_(3)^(−)),while NO_(3)^(−)was considered the most significant factor(p<0.05)in shaping fungal community.

Landfill Site Suitability Assessment Using Geographic Information System (GIS) and Analytic Hierarchy Process (AHP) in Butuan City, Philippines

Landfilling is one of the most effective and responsible ways to dispose of municipal solid waste(MSW).Identifying landfill sites,however,is a challenging and complex undertaking because it depends on social,environmental,technical,economic,and legal issues.This study aims to map the optimal sites that were environmentally suitable for locating a landfill site in Butuan City,Philippines.With reference to the policy requirements from DENR Section I,Landfill Site Identification Criteria and Screening Guidelines of National Solid Waste Management Commission,the integration of a Geographic Information System(GIS)model builder and Analytical Hierarchy Process(AHP)has been used in this study to address the aforementioned challenges related to the landfill site suitability analysis.Based on the generated sanitary landfill suitability map,results showed that Barangay Tungao(1131.42967 ha)and Florida(518.48 ha)were able to meet and consider the three(3)main components,namely economic,environmental,and physical criteria,and are highly suit­able as landfill site locations in Butuan City.It is recommended that there will conduct a geotechnical evaluation,involv­ing rigorous geological and hydrogeological assessment employing a combination of site investigation and laboratory techniques.In addition,additional specific social,ecological,climatic,and economic factors need to be considered(i.e.including impact on humans,flora,fauna,soil,water,air,climate,and landscape).

Landfill leachate production, quality and recirculation treatment in northeast China

Landfill leachate recirculation treatment process is a promising and economic way in northeast China due to the distinct season variation. In order to study the impact of recirculation on leachate production and its quality, two simulated sanitary landfill reactors, one with leachate recirculation and the other without, were placed outdoor in Harbin. The two-year experimental results indicated that leachate production was reduced by 86% with leachate recirculation and less or no facility for leachate treatment required. Recirculation could improve the leachate quality dramatically with lower COD, SS, NF4-N and higher pH level. Recirculation also could enhance waste degradation and stabilization and improve the efficiency of landfill. This study confirmed that leachate recirculation was a very feasible way for on-site landfill leachate treatment in cold areas.

Microbiological indication of municipal solid waste landfill non-stabilization

Accidental collapse resulted from unstable factors is an important technological problem to be solved in sanitary landfill. Microbiological degradation of organic matters in landfilled solid waste are an important unstable factor. A landfill reactor was thus manufactured and installed to examine quantitative and population dynamics of microorganisms during degradation of landfilled solid waste. It was showed that unstable landfill can be reflected and indicated by microbiological features such as rapidly decreased growth amount of microorganisms, no detection of fungi and actinomyces, and changing the dominant population into methanogenic bacteria and Acinotobacter.

A Life Cycle Comparison of Remote, Deployed Expeditionary Waste Management Scenarios

The current barrier to acquisition and utilization of viable waste-to-energy (WTE) technologies at remote or deployed expeditionary sites requires high capital and operation & maintenance costs. The impacts to environment and human health of differing expeditionary waste management strategies were compared using the Life Cycle Assessment software SimaPro 8.0. Emissions of individual waste management scenarios were compiled from peer-reviewed literature, converted to values compatible with SimaPro’s waste scenario inputs, and the calculated impacts compared using SimaPro’s pre-loaded methodologies. These calculated impacts and the economic impacts confirm that open-air burning of waste is not only dangerous to humans and the environment, but is also not cost-effective. Considering the economic effects and the mitigated human and environmental health impacts, WTE technologies may be a viable waste management strategy for the future.

Landfill site selection using multi cr iter ia decision making: Influential factors for comparing locations

Although a lot of research has focused on energy recovery and recycling of valuable materials from wastes to reduce loads on landfills,landfilling is still an inseparable part of solid waste management.Since landfills potentially pose a risk to human health and the surrounding environment,landfill site selection is an important endeavor that has to be carried out with great care.Choosing a suitable location for landfills depends on several factors and is a complicated procedure.In this paper,a comprehensive review of landfill site selection methods,with an emphasis on multi criteria decision making(multiple criteria decision analysis)has been presented.Assessments indicate that the most frequently used methods are weighted linear combination(WLC),ordered weighted averaging(OWA),analytic hierarchy process(AHP),fuzzy analytic hierarchy process(F-AHP),TODIM,fuzzy TODIM,analytic network process(ANP),fuzzy-analytic network process(F-ANP),and grey systems theory,each of which is discussed.The most widely used factors for selecting a landfill site are groundwater depth,surface water vicinity,elevation,land slope,soil permeability,soil stability,flooding susceptibility,lithology and stratification,faults,land use type,nearby settlements and urbanization,cultural and protected site vicinity,wind direction,roads,railways,proximity to building materials,pipelines and powerlines,and proximity to airports.

Effects of calcined aluminum salts on the advanced dewatering and solidification/stabilization of sewage sludge

The high moisture content （80%） in the sewage dewatered sludge is the main obstacle to disposal and recycling. A chemical dewatering and stabilization/solidification （S/S） alternative for the sludge was developed, using calcined aluminum salts （AS） as solidifier, and CaCl 2 , Na 2 SO 4 and CaSO 4 as accelerators, to enhance the mechanical compressibility making the landfill operation possible. The properties of the resultant matrixes were determined in terms of moisture contents, unconfined compressive strength, products of hydration, and toxicity characteristics. The results showed that AS exhibited a moderate pozzolanic activity, and the mortar AS 0 obtained with 5% AS and 10% CaSO 4 of AS by weight presented a moisture contents below 50%–60% and a compressive strength of （51.32 ± 2.9） kPa after 5–7 days of curing time, meeting the minimum requirement for sanitary landfill. The use of CaSO 4 obviously improved the S/S performance, causing higher strength level. X-ray diffraction, scanning electron microscopy and thermogravimetry- differential scanning calorimetry investigations revealed that a large amount of hydrates （viz., gismondine and CaCO 3 ） were present in solidified sludge, leading to the depletion of evaporable water and the enhancement of the strength. In addition, the toxicity characteristic leaching procedure （TCLP） and horizontal vibration （HJ 557-2009） leaching test were conducted to evaluate their environmental compatibility. It was found that the solidified products conformed to the toxicity characteristic criteria in China and could be safely disposed of in a sanitary landfill.