Bioremediation of petroleum‐impacted soils from investigation‐derived wastes

Optimal conditions for bioremediation of investigation‐derived wastes from petroleum‐impacted soils (PIS) were determined through biotreatability experiments. The PIS was collected as extruded cores obtained during sample drilling. These samples were processed into workable media prior to treatment in bioreactors. Soil moisture content in the bioreactors was adjusted to 30 percent, 40 percent, 50 percent (control), and 60 percent, dry‐weight basis, and nutrient levels were adjusted by applying fertilizer, yielding carbon (C) to nitrogen (N) ratios of 20:1, 10:1, and 5:1, versus a control C:N ratio of 140:1. Temperature, pH, viable bacterial plate counts, contaminant degradation rate, and microbial respiration were monitored. Concentrations of three selected branched alkanes in the aviation fuel contaminant, measured by gas chromatography, decreased for most treatments. The greatest degradation occurred with a moisture content of 40 percent and C:N ratio of 5:1. Increased contaminant degradation was consistent with increased microbial activity measured by respiration. There was poorer correlation between contaminant degradation and viable plate counts, which suggests that respirometry is a better measure of activity of the microbial population responsible for contaminant degradation. General plate counts, which enumerate only a fraction of the total population, may not be a reliable quantitative indicator of the actual microorganism population that is responsible for degradation. © 2003 Wiley Periodicals, Inc.     

Towards a cleaner production in developing countries: a case study in a Chilean tannery.

A Chilean leather tanning industry (tannery) was studied in terms of input/output (I/O) analysis of beamhouse, tanyard and retanning processes. The physical-chemical characterization of 19 streams were investigated. Streams from the beamhouse process and some streams from the retanning process were found to have high organic contents ranging from 2.5 to 18.1 g COD L(-1). The pH ranged between 3.45 and 12.28. Sulphur was found in most of the streams whereas chromium was detected in two wastewaters from the tanyard and in seven streams from the retanning process. Pollution prevention opportunities were evaluated and an appropriate treatment strategy was proposed. The main emphasis was on determining waste reduction measures that can be easily implemented and are not particularly expensive. Measures for reduction at source were proposed to reduce water and chemicals consumption and wastewater pollution. A so-called S(index) strategy was used to evaluate proposals on segregation and specific treatment of the main chromium- and sulphur-containing wastewaters. It was suggested that some streams may be re-used, but it is necessary to apply anaerobic or aerobic treatment first, depending on their organic load. Solid wastes were also evaluated and a proposal for their reduction and disposal was made.     

Trends and problems of solid waste management in developing countries: a case study in seven Palestinian districts

There is a great interest in solving problems related to municipal solid waste (MSW) management in the Palestinian territory. However, few studies have been done to assess the extent of these problems and suggest the best alternative solutions. This study aims at assessing MSW conditions in the seven major districts in northern West Bank, Palestinian territory. The study focuses on comparing several MSW management elements (such as collection, budget, and disposal) in municipalities, village councils, and refugee camps in the studied districts and the problems faced by these institutions in handling the waste. It also provides information on MSW collection service availability and waste disposal practices in the districts studied. It was found that, although MSW collection service was available for 98% of the residents in the areas surveyed, no proper treatment or landfill procedure was followed for the collected waste in most of these areas. Instead, waste burning in open dumpsites was the most common practice. Moreover, due to inefficient collection of waste disposal fees from the residents, municipalities were forced to sometimes cut the collection service and reduce its labor force, especially in villages. The budget for MSW management was between 2% and 8% of the total budget of the municipalities studied, indicating a low priority for this issue.     

Operation of a 27‐m3 biopile for the treatment of petroleum‐contaminated soil

Soil and groundwater contamination due to petroleum hydrocarbon spills is a frequent problem worldwide. In Mexico, even when programs oriented to the diminution of these undesirable events exist, in 2000, a total of 1,518 petroleum spills were reported. Exploration zones, refineries, and oil distribution and storage stations frequently are contaminated with total petroleum hydrocarbons (TPH); diesel fraction; gasoline fraction; benzene, toluene, ethyl benzene, and xylenes (BTEX); and polycyclic aromatic hydrocarbons (PAHs). Among the many methodologies available for the treatment of this kind of contaminated soil, bioremediation is the most favorable, because it is an efficient/low‐cost option that is environmentally friendly. This article discusses the capability of using a biopile to treat soils contaminated with about 40,000 mg/kg of TPH. Design and operation of a 27‐m³ biopile is described in this work, including microbiological and respirometric aspects. Parameters such as TPH, diesel fraction, BTEX, and PAHs considered by the U.S. Environmental Protection Agency were measured in biopile samples at 0, 2, 4, 6, 8, 10, and 22 weeks. A final average TPH concentration of 7,300 mg/kg was achieved in 22 weeks, a removal efficiency of 80 percent. © 2007 Wiley Periodicals, Inc.     

Solid waste recycling within higher education in developing countries: a case study of the University of Lagos

To create a truly circular economy requires a shift from the traditional view of waste disposal to one of resource management. This is particularly important in developing countries, where municipal waste generation is increasing, and efficient recovery of economic value from waste is rarely achieved. Conducted in the University of Lagos (UoL), Nigeria, this study investigated the efficiency of a recycling scheme with the goal of making recommendations to improve the process. UoL’s recycling policy centers around source segregation of waste into color-coded bins. Waste audit was carried out using the output method and interviews were conducted with staff from the waste management team to understand practices on campus. Substantial contamination of colored bins with non-target material was observed. Organics (30%), mixed plastics (28%) and paper (24%) were the most abundant materials, hence have the greatest potential for recovery, and income generation, if segregation rates could be improved. Despite its recycling policy and infrastructure, 99% of UoL waste was going to landfill. Poor policy implementation results in low recovery rates. Targeted waste reduction and increased material recovery would enhance efficiency. Improved awareness of recycling benefits, in addition to policy enforcement, could serve as tools to increase stakeholder participation in recycling.

     

Solid waste management in least developed countries: current status and challenges faced

Journal of Material Cycles and Waste Management - Increasing solid waste generation is a major concern worldwide, with least developed countries (LDCs) particularly affected due to ineffective...     

Characterization of dry fractions contained in municipal solid waste in developing countries: a case study of a region in Morocco

Journal of Material Cycles and Waste Management - Despite its impact on the environment, the most widely used method for waste management in African countries is landfilling. Energy recovery, in...     

Activity and emission inventory of open waste burning at the household level in developing countries: a case study of Semarang City

Journal of Material Cycles and Waste Management - In this study, total burned household waste and the potential emissions released from waste burning in Semarang City, Indonesia, were estimated....     

Agricultural waste as household fuel: Techno-economic assessment of a new rice-husk cookstove for developing countries

In many rural contexts of the developing world, agricultural residues and the organic fraction of waste are often burned in open-air to clear the lands or just to dispose them. This is a common practice which generates uncontrolled emissions, while wasting a potential energy resource. This is the case of rice husk in the Logone Valley (Chad/Cameroon). In such a context household energy supply is a further critical issue. Modern liquid fuel use is limited and traditional solid fuels (mainly wood) are used for daily cooking in rudimentary devices like 3-stone fires, resulting in low efficiency fuel use, huge health impacts, increasing exploitation stress for the local natural resources. Rice husk may be an alternative fuel to wood for household energy supply. In order to recover such a biomass, the authors are testing a proper stove with an original design. Its lay-out (featuring a metal-net basket to contain the fuel and a chimney to force a natural air draft) allows a mix of combustion/gasification of the biomass occurring in a completely burning fire, appropriate for cooking tasks. According to results obtained with rigorous test protocols (Water Boiling Test), different lay-outs have been designed to improve the performance of the stove. Technical and economic issues have been addressed in the development of such a model; building materials have been chosen in order to guarantee a cost as low as possible, using locally available items. The feasibility of the introduction of the stove in the studied context was assessed through an economic model that keeps into account not only the technology and fuel costs, but also the energy performance. According to the model, the threshold for the trade-off of the stove is the use of rice husk to cover 10–15% of the household energy needs both with traditional fireplaces or with improved efficiency cookstoves. The use of the technology proposed in combination with improved woodstove would provide householders with an appropriate and convenient cooking technology portfolio, increasing the opportunities of choice of the preferred energy system for the user and allowing significant savings for the family budget (up to 50% of the total annual cooking energy expenditure). The proposed model may be used also as a tool for the evaluation of the affordability or for the comparison of different cooking technologies also in other similar contexts, given their specific techno-economic parameter values.     

Environmental impact assessment on the construction and operation of municipal solid waste sanitary landfills in developing countries: China case study

An inventory of material and energy consumption during the construction and operation (C&O) of a typical sanitary landfill site in China was calculated based on Chinese industrial standards for landfill management and design reports. The environmental impacts of landfill C&O were evaluated through life cycle assessment (LCA). The amounts of materials and energy used during this type of undertaking in China are comparable to those in developed countries, except that the consumption of concrete and asphalt is significantly higher in China. A comparison of the normalized impact potential between landfill C&O and the total landfilling technology implies that the contribution of C&O to overall landfill emissions is not negligible. The non-toxic impacts induced by C&O can be attributed mainly to the consumption of diesel used for daily operation, while the toxic impacts are primarily due to the use of mineral materials. To test the influences of different landfill C&O approaches on environmental impacts, six baseline alternatives were assessed through sensitivity analysis. If geomembranes and geonets were utilized to replace daily and intermediate soil covers and gravel drainage systems, respectively, the environmental burdens of C&O could be mitigated by between 2% and 27%. During the LCA of landfill C&O, the research scope or system boundary has to be declared when referring to material consumption values taken from the literature; for example, the misapplication of data could lead to an underestimation of diesel consumption by 60–80%.     

Assessment of economic viability of solid waste service provision in small settlements in developing countries: case study Rosetta, Egypt

Problems associated with solid waste management (SWM) service provision in developing countries are reaching an ever increasing magnitude, leading to considerable adverse impacts on the environment and quality of life of the inhabitants. Such problems are usually associated with limited managerial, technical and financial capabilities of municipal authorities. Municipal authorities in Egypt that are responsible for SWM services have always been accused of providing a less than satisfactory service, leading to huge quantities of solid waste being uncollected. This study assesses the potential for the provision of an effective and sustainable service, by estimating willingness of the residents to pay for such a service and the cost involved in its provision. The study covered the Rosetta urban centre and its adjacent areas, which are located in the northwestern part of the Nile Delta. It was found that, from an economic perspective, a viable SWM service could be provided in the study area using local funds. In order to increase the likelihood of success of such a service, it may be provided by a local firm or a cooperative to be established for that purpose.     

Difficulties in applying extended producer responsibility policies in developing countries: case studies in e-waste recycling in China and Thailand

Developing Asian countries have started to apply the principle of extended producer responsibility (EPR) to electronics and electrical equipment waste (e-waste). This policy approach aims to give electronic appliance manufacturers and importers responsibility for the collection and recycling of discarded electronic equipment. China and Thailand have drafted regulations on the recycling of e-waste with common characteristics such as the financial responsibility of producers and subsidies for collection. Although the proposed system is sensible, taking into account the fact that e-waste is a market-traded commodity, there are two major difficulties in implementing EPR in developing countries. First, it may be difficult for governments to collect funds from producers or importers if smuggled, imitation, or small shop-assembled products have a large share in the market. Second, the system creates incentives for collectors and recyclers to over-report the amount of collected e-waste in order to gain extra subsidies from the fund. Other policy measures such as the enforcement of pollution control regulations on informal recyclers, the prevention of smuggling, and the protection of intellectual property rights should accompany EPR policies.     

Development of a site‐specific cleanup goal for PAHs in soil based on anthropogenic background levels

During removal of an industrial landfill in Folsom, California, fill material was excavated and processed through a mechanical screening plant to segregate soil from construction and demolition debris. The segregated soil was stockpiled and analyzed for a wide range of chemical groups to determine if the soil could be backfilled on‐site. The analytical results indicated many of the stockpiles had concentrations of polycyclic aromatic hydrocarbons (PAHs) that exceeded US EPA Regional Screening Levels, and a large quantity of soil was initially classified as requiring off‐site disposal at considerable cost. Because PAHs are ubiquitous in urban settings and the landfill did not contain a significant source of PAHs, development of a site‐specific PAH cleanup goal was proposed to regulators. Cal/EPA guidance for using on‐site data to develop a background threshold for metals was applied to the development of the PAH cleanup goal. The Cal/EPA approach involves demonstrating whether the data belong to a single population or multiple populations based on data distribution tests and probability plots. This article explains the statistical and graphical methods that were used to demonstrate that the Cal/EPA approach was valid for PAHs and that the calculated cleanup level was consistent with published anthropogenic background levels of PAHs in California and across the United States. The site‐specific PAH cleanup goal enabled most of the soil to be backfilled on‐site, saving about $227,000 in transportation and disposal costs, and regulators subsequently approved unrestricted future use of the property. © 2010 Wiley Periodicals, Inc.     

Treatment of mercury‐contaminated soils with activated carbon: A laboratory,field, and modeling study

A series of laboratory batch leaching tests was conducted to evaluate the performance of different activated carbons in stabilizing mercury in soils. Based on the results of these experiments, an amendment application rate of 5 percent powdered activated carbon (PAC) was selected for in situ field application at a former industrial facility. A geochemical model was also developed to simulate the interactions between mercury and activated carbon in vadose‐zone soils. Modeling was used to (1) better understand possible mercury sequestration mechanisms and (2) predict the in situ performance of PAC. Model results indicate dissolved mercury concentrations observed in batch tests are consistent with equilibrium partitioning of mercury between dissolved organic matter, soil organic matter, and PAC. Activated carbon is predicted to reduce dissolved mercury concentrations via two mechanisms: (1) the formation of stable mercury complexes on PAC surfaces and (2) the direct adsorption of dissolved organic matter that would otherwise be available for mercury dissolution. Study results demonstrate PAC effectiveness for site soils with mercury concentrations below 200 mg/kg. © 2010 Wiley Periodicals, Inc.     

Utilization of nanoscale zero‐valent iron for source remediation—A case study

A pilot‐scale study was performed using a palladium‐catalyzed and polymer‐coated nanoscale zero‐valent iron (ZVI) particle suspension at the Naval Air Station in Jacksonville, Florida. A total of 300 pounds of nanoscale ZVI particle suspension was injected via a gravity feed and recirculated through a source area containing chlorinated volatile organic compounds (VOCs). The recirculation created favorable mixing and distribution of the iron suspension and enhanced the mass transfer of sorbed and nonaqueous constituents into the aqueous phase, where the contaminants could be reduced. Between 65 and 99 percent aqueous‐phase VOC concentration reduction occurred, due to abiotic degradation, within five weeks of the injection. The rapid abiotic degradation processes then yielded to slower biological degradation as subsequent decreases in ‐elimination parameters were observed—yet favorable redox conditions were maintained as a result of the ZVI treatment. Post‐treatment analyses revealed cumulative reduction of soil contaminant concentrations between 8 and 92 percent. Aqueous‐phase VOC concentrations in wells side gradient and downgradient of the source were reduced up to 99 percent and were near or below applicable regulatory criteria. These reductions, coupled with the generation of innocuous by‐products, indicate that nanoscale ZVI effectively degraded contamination and reduced the mass flux from the source, a critical metric identified for source treatment. A summary of this project was recently presented at the US EPA Workshop on Nanotechnology for Site Remediation in Washington, D.C., on October 21–22, 2005. This case study supplied evidence that nanoscale zero valent iron, an emerging remediation technology, has been implemented successfully in the field. More information about this workshop and this presentation can be found at www.frtr.gov/nano/index.htm. © 2006 Wiley Periodicals, Inc.     

Characterization and quantification of solid waste generation in the Niger Delta Region of Nigeria: a case study of Ogbe-Ijoh community in Delta State

Journal of Material Cycles and Waste Management - In this study, the composition, characteristics and generation rates of solid waste (SW) in Ogbe-Ijoh community were investigated to provide...     

The investigation of a class of capacitated arc routing problems: the collection of garbage in developing countries

The collection, transport and disposal of solid waste, which is a highly visible and important municipal service, involves a large expenditure but receives, scant attention. This problem is even more crucial for large cities in developing countries due to the hot weather. A constructive heuristic which takes into account the environmental aspect as well as the cost is proposed to solve the routing aspect of garbage collection. This is based on a look-ahead strategy which is enhanced by two additional mechanisms. Interesting results were obtained when tested on instances with and without the presence of the effect of the environment.