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PubMed2005

Nitrate movement in shallow ground water from swine-lagoon-effluent spray fields managed under current application regulations.

Rapid increases in the swine (Sus scrofa domestica) population in the 1990s and associated potential for nitrate N pollution of surface waters led the state of North Carolina to adopt stringent waste management regulations in 1993. Our objectives were to characterize (i) nitrate N movement from waste application fields (WAFs) in shallow ground water, and (ii) soil, hydrologic, and biological factors influencing the amount of nitrate N in the adjacent stream. A ground water monitoring study was conducted for 36 mo on a swine farm managed under new regulations. Water table contours and lack of vertical gradients indicated horizontal flow over most of the site. Nitrate N concentrations in water from shallow wells in WAFs averaged 30 +/- 19 mg L(-1) and delta15N ratios for nitrate N were between +20 and +25 per mil. Nitrate N concentration decreased from field-edge to streamside wells by 22 to 99%. Measurement of delta18O and delta15N enrichment of nitrate in ground water throughout the WAF-riparian system indicated that denitrification has not caused significant 15N enrichment of nitrate. Over a 24-mo period, delta15N ratios for nitrate N in the stream approached delta15N ratios for nitrate N in ground water beneath WAFs indicating delivery of some waste-derived nitrate N to the stream in shallow ground water. Nitrate N concentrations in the stream were relatively low, averaging 1 mg L(-1). Dilution of high nitrate N water in shallow horizontal flow paths with low nitrate N water from deeper horizontal flow paths at or near the stream, some denitrification as ground water discharges through the stream bottom, and some denitrification in riparian zone contributed to this low nitrate N concentration.

Animals↗

PubMed1998

Comparative evaluation of automated systems in immunohistochemistry.

From October 1995 to March 1997, we evaluated five instruments for immunohistochemistry automation: The Techmate 500 (Dako), the Ventana 320/ES (Ventana), the Optimax Plus (Biogenex, Menarini), the Cadenza (Shandon), and the Immunostainer (Coulter-Immunotech). The aim of the evaluation was to compare the different instruments to the manual method in our laboratory which performs about 17 500 immunohistochemistries per year. PRINCIPLE: Three instruments use flat immunohistolabelling, the others use capillarity immunohistolabelling. ANALYTICAL FLEXIBILITY: we compared the number of protocols per run, the multitask capability, and the ability to adapt manual protocols to the different instruments. To compare the management of the workcell, we used the level of selfchecking, reagent and slides preparation time, and waste management. We measured the duration of the different steps of the process, the throughput in slides/h, and the operator working time per slide. Compared to the manual method, the total cost for reagents and consumables was found to be multiplied by 3 for the Ventana which is a closed system, by 2 for the Techmate, by 1.5 for the Optimax and Cadenza, and identical for the Immunostainer. CONCLUSION: Automation of immunohistochemistry is now possible; the Optimax is still in development, small laboratories will appreciate the Cadenza, laboratories requiring a high flexibility with many protocols will use the Immunostainer open system, laboratories with few technicians will prefer the Ventana closed instrument, now available as the Nexes modular system.

Automation↗

PubMed1978

Solid wastes from nuclear power production.

Radioactivity in nuclear power effluents is negligible compared to that in retained wastes to be disposed of as solids. Two basic waste categories are those for which shallow disposal is accepted and those for which more extreme isolation is desired. The latter includes "high level" wastes and others contaminated with radionuclides with the unusual combined properties of long radioactive half-life and high specific radiotoxicity. The favored method for extreme isolation is emplacement in a deep stable geologic formation. Necessary technologies for waste treatment and disposal are considered available. The present program to implement these technologies is discussed, including the waste management significance of current policy on spent nuclear fuel reprocessing. Recent difficulties with shallow disposal of waste are summarized.

Geological Phenomena↗

PubMed2006

Incineration of municipal and assimilated wastes in France: assessment of latest energy and material recovery performances.

Incineration has an important place in waste management in France. In 2003, around 130 incineration plants have treated 12.6 Mt of non-dangerous waste, mainly composed of household waste (10.8 Mt), non-dangerous waste from industry, business, services (1.0 Mt), sewage sludge (0.2 Mt) or clinical waste (0.1 Mt). The incineration of these wastes generated 3.0 Mt of bottom ash of which 2.3 Mt were used for roads construction and 0.2 Mt of ferrous and non-ferrous metal were recycled. It also produced 2,900,000 MWh of electricity, of which 2,200,000 MWh were sold to Electricité de France (EDF) and 9,100,000 MWh of heat, of which 7,200,000 MWh were sold to private or public users. These French incinerators of non-hazardous waste are currently being thoroughly modernized, thus making possible the consolidation and the enhancement of their environmental and energy performance. This process is related to the implementation of the European Directive 2000/76/CE whose expiration date is 28 December 2005. Upon request of ADEME, the engineering company GIRUS has realised the first technical and economical evaluation of works necessary to bring incinerators into compliance. The financial estimations, carried out in 30 June 2003, show that the investments to be devoted could reach 750 million euros. This assessment shed new light on the situation of non-hazardous waste incinerators, including an identification and a rank ordering for each incinerator of the most frequent and the most complex non-conformities to be solved in term of cost and delay. At last, this assessment gives the solutions for each non-compliance.

Energy Transfer↗

PubMed1984

Immobilization and geological disposal of nuclear fuel waste.

The Canadian Nuclear Fuel Waste Management Program is developing methods for the safe disposal of both used nuclear fuel and fuel recycle waste. The disposal strategy is based on interim storage of the used fuel, immobilization of either used fuel or recycle waste, and disposal, deep in a stable geological formation in the Canadian Shield. The disposal concept proposes a multibarrier system to inhibit the release of the radioactive waste from the disposal vault. The principal components of the multibarrier system are (i) the waste form in which the radionuclides are immobilized, (ii) engineered barriers including high integrity containers, buffers and backfills designed to retard the movement of groundwaters in the disposal vault, and (iii) the natural barrier provided by the massive geological formation itself. The research programs to investigate this concept are discussed briefly. Several different waste forms are being developed for the immobilization of high-level fuel recycle waste, including glass, glass-ceramics and crystalline materials. Dissolution of these materials in groundwater is the only likely scenario that could lead to radionuclide release. The factors that influence the aqueous dissolution behaviour of these materials are reviewed.

Ceramics↗

PubMed2004

Sampling household waste at source: lessons learnt in Gaborone.

Municipal solid waste (MSW) quantity and composition analysis is fundamental for the planning of municipal waste management services. The purpose of this paper is to report the results and experiences of sampling household waste at the source of generation in Gaborone, Botswana. The average generation rate, in kg capita(-1) day(-1), and percentages of various components of waste in Gaborone were determined using a statistically designed household sampling survey. The survey covered 47 households with different socio-economic characteristics over 21 days with 893 samples obtained. The results showed that the average waste generation rate for Gaborone was 0.33 kg capita(-1) day(-1). Contrary to common belief, the waste generation rate measured as in weight units was found not be directly related to household income. However, the packaging fractions of plastic and paper measured as volume had a direct relationship with household income. Across all income groups, the putrescible waste fraction constituted the highest proportion of the waste stream at approximately 68%. The main general conclusion is on the importance of practical considerations. As much as statistically designed sampling procedures provide a useful means of estimating the quantity and composition of household waste at source of generation, there are some practical issues that should be carefully considered during sampling to improve the accuracy and relevance of the results.

Botswana↗

PubMed2006

The costs of introducing a malaria vaccine through the expanded program on immunization in Tanzania.

This report presents an approach to costing the delivery of a malaria vaccine through the expanded program on immunization (EPI), and presents the predicted cost per dose delivered and cost per fully immunized child (FIC) in Tanzania, which are key inputs to the cost-effectiveness analysis. The costs included in the analysis are those related to the purchase of the vaccine taking into account the wastage rate; the costs of distributing and storing the vaccine at central, zonal, district, and facility level; those of managing the vaccination program; the costs of delivery at facility level (including personnel, syringes, safety boxes, and waste management); and those of additional training of EPI personnel and of social mobilization activities. The average cost per FIC increases almost linearly from US 4.2 dollars per FIC at a vaccine price of US 1 dollars per dose to US 31.2 dollars at vaccine price of US 10 dollars per dose. The marginal cost is approximately 5% less than the average cost. Although the vaccine price still determines most of the total delivery costs, the analysis shows that other costs are relevant and should be taken into account before marketing the vaccine and planning its inclusion into the EPI.

Cost-Benefit Analysis↗

PubMed2006

Ammonia emissions from Swine waste lagoons in the Utah great basin.

In animal production systems (poultry, beef, and swine), current production, storage, and disposal techniques present a challenge to manage wastes to minimize the emissions of trace gases within relatively small geographical areas. Physical and chemical parameters were measured on primary and secondary lagoons on three different swine farming systems, three replicates each, in the Central Great Basin of the United States to determine ammonia (NH3) emissions. Nutrient concentrations, lagoon water temperature, and micrometeorological data from these measurements were used with a published process model to calculate emissions. Annual cycling of emissions was determined in relation to climatic factors and wind speed was found the predominating factor when the lagoon temperatures were above about 3 degrees C. Total NH3 emissions increased in the order of smallest to largest: nursery, sow, and finisher farms. However, emissions on an animal basis increased from nursery animals being lowest to sow animals being highest. When emissions were compared to the amount of nitrogen (N) fed to the animals, NH3 emissions from sows were lowest with emissions from finisher animals highest. Ammonia emissions were compared to similar farm production systems in the humid East of the United States and found to be similar for finisher animals but had much lower emissions than comparable humid East sow production. Published estimates of NH3 emissions from lagoons ranged from 36 to 70% of feed input (no error range) compared to our emissions determined from a process model of 9.8% with an estimated range of +/-4%.

Ammonia↗

PubMed2002

Urban waste recycling behavior: antecedents of participation in a selective collection program.

The aim of this study is to analyze the antecedents of urban waste recycling behavior. To achieve this goal, a concrete urban waste management program was chosen. The study focuses on the Selective Collection Program (SCP) in Zaragoza, a medium-sized city in northeastern Spain. The research starts with a conceptual model in which the variables that potentially affect recycling behavior can be classified into two groups: incentives and barriers. Moreover, the sociodemographic characteristics of the individuals are included in our study. Given that the proposed model requires specification of latent variables or constructs, the analysis is based on the Structural Equation Models (SEM) methodology. The results revealed that environmental awareness, knowledge of the environmental impact of urban waste, and the positive perception of management by local government exercise a positive effect on individual recycling behavior, while perceived personal difficulties (space and time availability) and distance to and from the container have a negative effect. As regards sociodemographic variables, this study found that annual family income sustains a negative relationship with recycling behavior, while age maintains a positive one. The results obtained clearly show the important role that the public authorities play, especially municipal governments, in achieving the waste recycling objectives established in accordance with international legislation.

Conservation of Natural Resources↗

PubMed2005

Biostabilization-biodrying of municipal solid waste by inverting air-flow.

The process of biodrying could be a good solution for municipal solid waste management, allowing the production of fuel with an interesting energy content. Previous work (Adani, F., Baido, D., Calcaterra, E., Genevini, P.L., 2002. The influence of biomass temperature on biostabilization-biodrying of municipal solid waste. Bioresource Technology 83 (3), 173-179) has indicated that appropriate management of the processing parameters (air-flow rate and biomass temperatures) could achieve biomass drying in very short times (8-9 days). However, the data of that work also evidenced that if the conditions do not consider pile turning, and the air-flow is always from one direction, temperature gradients arise within the biomass, resulting in a lack of homogeneity in the moisture and energy content of the final product. Therefore, a new laboratory study was conducted on municipal solid waste biodrying-biostabilization in an effort to obtain homogeneous final products. Our proposal to solve this lack of homogeneity is to periodically invert the air-flow direction. Thus, in line with a previous study, two trials, A and B, were carried out, dividing the biomass into three layers to study temperature and moisture gradients throughout the process, and a third trial (C) simulating air-flow inversion at regular intervals was introduced. The results suggest that the daily inversion of air-flow eliminates marked temperature differences and leads to a homogeneous final product.

Bacteria↗

PubMed2000

Human health risk assessment and management in hazardous waste site contaminated by polychlorinated benzenes.

The improper management of large quantity of chemical waste of a chemical plant caused considerable soil contamination on a temporary hazardous waste disposal site. Initial and action-oriented exposure and health risk assessment was carried out in early 90's. The dominant contaminants were tetrachlorobenzenes (TeCBs), pentachlorobenzene and hexachlorobenzene (HCB). Concentration of TeCBs in top soil layer and vadoze zone exceeded several g/kg. After taking appropriate technical measures quantitative health risk assessment was performed for the target population living in the surrounding settlements. Health risk estimates to HCB ingested or inhaled with suspended dust and soil particulates showed that carcinogenic risk values lower than 10(-6) i.e. below the acceptable risk. For other chlorobenzenes that cause non-cancer toxic effects risk quotients showed marked health hazard inside the dump and small potential risk in vicinity. However, this assessment is based on limited monitoring data, additional information is needed to substantiate this conclusion.

Benzene Derivatives↗

PubMed1998

The source and fate of Pb in contaminated soils at the urban area of Falun in central Sweden.

For centuries the city of Falun in central Sweden has been an important industrial region of copper mining, producing sulphuric acid and paint pigment. The mining and chemical industries have generated vast amounts of wastes which have been deposited around the areas. A large part of the city is now built on the wastes. In the last two decades, significant amounts of work on the waste management have been conducted. Previous investigations showed that the soils of the urban areas have been contaminated by the wastes with a rather high level of lead (Pb). What is the speciation of soil-Pb? How does the Pb reach the biosphere? This paper gives answers toward these environmental problems. This study investigates the distribution of Pb in the urban soils by means of chemical and mineralogical methods the quantity and quality of the fallout particles; and traces the potential sources of contamination. The data indicate that in Falun urban soil-Pb speciation, many mainly be associated with some mineral phases, e.g. Fe and Mn oxides, sulphides, Pb-carbonates, as well as retained by organic matters and clay minerals. The concentrations of water soluble Pb are very low. Because of the properties of the Pb-bearing phases, the high concentrations of soil-Pb in the urban area are not likely to have a significant affect on the blood-Pb levels of pre-school children living in the urban areas. Lead and arsenic are found to be associated with iron oxides in the fallout particles collected in the areas. These fine grained particles may have been distributed through wind-related transportation from the industrial wastes dumped in the areas.

Biological Availability↗

PubMed2003

Sequestration of metals in carbonated municipal solid waste incineration (MSWI) fly ash.

Waste management is in need of a reliable and economical treatment method for metals in fly ashes from municipal solid waste incineration (MSWI). However, no state-of-the-art technique has gained wide acceptance yet. This paper is a synthesis of five elsewhere published investigations covering a project which aimed to assess the possibilities and limitations of adding carbon dioxide (CO2) to fly ash as a stabilization method. Carbonation factors that were studied are the partial pressure of carbon dioxide (CO2), the addition of water, the temperature, and the reaction time. Laboratory experiments were performed applying methods such as factorial experimental design, thermal analysis, scanning electron microscopy (SEM), X-ray diffraction (XRD), and leaching assays including pHstat titration and sequential extraction. Leaching data were verified and complemented using chemical equilibrium calculations. Data evaluation was performed by means of multivariate statistics such as multiple linear regression, principal component analysis (PCA), and partial least squares (PLS) modeling. It was found that carbonation is a good prospect for a stabilization technique especially with respect to the major pollutants lead (Pb) and zinc (Zn). Their mobility decreased with increasing factor levels. Dominating factors were the partial pressure of CO2 and the reaction time, while temperature and the addition of water were of minor influence. However, the treatment caused a mobilization of cadmium (Cd), requiring further research on possible countermeasures such as metal demobilization through enhanced silicate formation.

Biological Availability↗

PubMed2007

Municipal solid waste characteristics and management in Allahabad, India.

Increasing population levels, rapid economic growth and rise in community living standard accelerates the generation rate of municipal solid waste (MSW) in Indian cities. Improper management of MSW causes hazards to inhabitants. The objectives of the study are to determine the quantitative and qualitative characteristics of MSW along with basic information and to create GIS maps for Allahabad city. The samples have been randomly collected from various locations and analyzed to determine the characteristics of MSW. A questionnaire survey has been carried out to collect data from inhabitants including MSW quantity, collection frequency, satisfaction level, etc. The Geographic Information System (GIS) has been used to analyze existing maps and data, to digitize the existing sanitary ward boundaries and to enter the data about the wards and disposal sites. The total quantity of MSW has been reported as 500 ton/day, and the average generation rate of MSW has been estimated at 0.39 kg/capita/day. The generated ArcGis maps give efficient information concerning static and dynamic parameters of the municipal solid waste management (MSWM) problem such as the generation rate of MSW in different wards, collection point locations, MSW transport means and their routes, and the number of disposal sites and their attributes.

Cities↗

PubMed2005

Interactive analysis of waste recycling and energy recovery program in a small-scale incinerator.

Conflicting goals affecting solid waste management are explored in this paper to find the best implementation of resource recovery with a small-scale waste-to-energy process. Recycling paper and plastic material often leaves a shortage of thermal energy to support incineration that forces operators to supplement the process with auxiliary fuels. Although there are considerable profits to be made from material recovery, the increase of fuel usage causes conflict given that it is cost prohibitive. A series of trials performed on a small-scale 1.5-t/day incineration plant with a cyclone heat recovery system found that material recycling can impede performance. Experimental results are expressed as empirical regression formulas with regard to combustion temperature, energy transfer, and heat recovery. Process optimization is possible if the waste moisture content remains <30%. To test the robustness of the optimization analysis, a series of sensitivity analyses clarify the extent of material recycling needed with regard to plastic, paper, and metal. The experiments also test whether the moisture in the waste would decrease when recycling paper because of its exceptional capacity to absorb moisture. Results show that recycling paper is strongly recommended when the moisture content is >20%, whereas plastic recycling is not necessary at that moisture condition. Notably, plastic recovery reduces the heat needed to vaporize the water content of the solid waste, thus it is recommended only when the moisture content is <10%. For above-normal incineration temperatures, plastic recycling is encouraged, because it removes excess energy. Metal is confirmed as an overall priority in material recycling regardless of the moisture content of the incoming waste.

Conservation of Energy Resources↗

PubMed2001

Municipal solid waste characteristics and management in China.

The purpose of this investigation is to evaluate the current status and identify the problems of municipal solid waste (MSW) management in China in order to determine appropriate remedial strategies. This is the first of two papers, discussing primarily the general characteristics of MSW and its management in China. The second paper focuses on specific remedial strategies. MSW generation in China has increased rapidly in the past 20 years from 31.3 million tons in 1980 to 113.0 million tons in 1998. The annual rate of increase is 3-10%. The average generation per capita is 1.0 kg/day (0.38 t/year). Nearly one-half of the waste generated is dumped in the suburbs, where the accumulated quantity has reached 6 billion tons, which has caused heavy environmental pollution. This paper provides information on MSW management in China, such as MSW generation and its physical, chemical, and biological properties. Low calorific value and high moisture content characterize China's municipal waste. Other issues related to MSW management in China are also discussed, including the factors that influence MSW generation quantity and

China↗

PubMed2006

Estimation of future outflows and infrastructure needed to recycle personal computer systems in California.

The objectives of the present study are to estimate future quantities of electronic waste (e-waste) for which appropriate infrastructure needs to be established, and to the estimate the total cost for e-waste recycling in California. Estimation of the future amounts of e-waste as a function of time is critical to effective e-waste management. To generate estimates, we use a time-series materials flow analysis model (MFAM). The model estimates future e-waste quantities by modeling the stages of production, usage, and disposal. We consider four scenarios for the estimation of future e-waste generation in order to consider the effects of exportation outside the State of California and of user preferences to store or to recycle the e-waste. These efforts were further investigated through the use of sensitivity analysis. The results of the present research indicate that the outflow (recycling) amount of central processing units (CPUs) will increase and will reach approximately 8.5 million units per year in 2013, but the outflow (recycling) of cathode ray tube (CRT) monitors will decrease from 2004 in California because of the replacement of CRT monitors by liquid crystal display (LCD) monitors. In 2013, the cost for CPU recycling will be 1.7 times higher than that in 2005. But for CRT monitors, the cost for recycling in 2013 will be negligible. After the State of California enacted the ban on landfill disposal of e-waste, recycling became the most common end-of-life (EOL) option in California. Also, after 2005, the State of California will need more than 60 average-capacity materials recovery facilities (MRFs), to recycle the number of personal computer systems generated, which represents an investment in capital of over 16 million dollars.

California↗

PubMed2000

[Measures for the disposal of non-regulated alternative medical wastes--cloned DNA of amplified DNA as waste materials].

Cloned DNA of amplified DNA, synthesized oligomer DNA and peptide nucleic acid is a candidate for hazardous medical waste material. The numerous identical base sequence of DNA has a risk associated with its handling in a laboratory and medical waste. To avoid the risk SD box, NaOCl, filtered chip of micropipette and a clean-bench are recommended for waste management.

Animals↗