The challenge of electronic waste (e-waste) management in developing countries

Information and telecommunications technology (ICT) and computer Internet networking has penetrated nearly every aspect of modern life, and is positively affecting human life even in the most remote areas of the developing countries. The rapid growth in ICT has led to an improvement in the capacity of computers but simultaneously to a decrease in the products lifetime as a result of which increasingly large quantities of waste electrical and electronic equipment (e-waste) are generated annually. ICT development in most developing countries, particularly in Africa, depends more on secondhand or refurbished EEEs most of which are imported without confirmatory testing for functionality. As a result large quantities of e-waste are presently being managed in these countries. The challenges facing the developing countries in e-waste management include: an absence of infrastructure for appropriate waste management, an absence of legislation dealing specifically with e-waste, an absence of any framework for end-of-life (EoL) product take-back or implementation of extended producer responsibility (EPR). This study examines these issues as they relate to practices in developing countries with emphasis on the prevailing situation in Nigeria. Effective management of e-waste in the developing countries demands the implementation of EPR, the establishment of product reuse through remanufacturing and the introduction of efficient recycling facilities. The implementation of a global system for the standardization and certification/labelling of secondhand appliances intended for export to developing countries will be required to control the export of electronic recyclables (e-scarp) in the name of secondhand appliances.     

EEG bioeffects on cochlear deaf from cellular phones

Objectives This paper aims to provide evidence of an inductive electromagnetic bioeffect on the human brain, which is independent from sound waves and produced by mobile phones, in proximal field, through correlating the EEG data obtained from electrodes placed on both normal and cochlear deaf individuals. Methods Two groups of subjects are placed under controlled electromagnetic conditions inside a Faraday chamber, 12 healthy and another 12 suffering from cochlear deafness). Each is sitting on a chair, fitted with additional support, and holding a cellular phone 2 cm away form the right auricular, in order to avoid a thermal effect as much as possible. All of them, relaxed and with their eyes closed, are EEG recorded in a basal state with their mobile phones off. Then, each of them is again recorded under the same conditions but with the mobile on and listening to the same conversation. In order to assess the observed EEG changes, a statistical analysis by means of the FFT (Fast Fourier Transform) was carried out. Results For both, healthy and cochlear deaf, assimilation or integration of the mobile phone signal by some electrodes is to be found. This is due to the increase of amplitudes for alpha and theta waves, whereas the signal is not integrated in other electrodes. By correlating the spectra of frequencies of corresponding EEG records for the same brain areas, we have not observed significative differences for both groups. Conclusions A possible electromagnetic direct inductive, non-thermal, bioeffect on the human brain is observed. This effect is produced by the use of mobile phones and it bears no relation to the sound waves.     

Fire and explosion risk assessment for large-scale oil export terminal

Now in Russian Federation and other countries large-scale oil terminals (volume of one tank exceeds 100 000 m³, total volume of tanks exceeds 300 000 m³) are designed and constructed. Therefore fire safety of such objects becomes a very important task, solution of which is hardly possible without detail fire risk assessment. This study is aimed to a solution of this problem. Potential, individual and social risks were calculated. The potential risk was defined as a frequency of occurrence of hazardous factors of fires and explosions in a given point of space (the so-called risk contours). The individual risk was defined as a frequency of injuring a given person by hazardous factors of fires and explosions. Time of presence of this person in hazardous zones (near the hazardous installation) is taken into account during calculations of the individual risk. Social risk was defined as a dependence of frequency of injuring a given number of people by hazardous factors of fires and explosions on this number. In practice the social risk is usually determined on injuring not less than 10 people.

The oil terminal under consideration includes the following main parts: crude oil storage consisting of three tanks of volume 100 000 m³ each, input crude oil pipeline of diameter 0.6 m, crude oil pumps, output crude oil pipeline of diameter 0.8 m, auxiliary buildings and facilities. The following main scenarios of tank fires have been considered: rim seal fire, pool fire on a surface of a floating roof, pool fire on a total cross-section surface of the tank, pool fire in a dyke, explosions in closed or semiclosed volumes. Fires and explosions in other parts of the terminal are also taken into account. Effects of escalation of accidents are considered.

Risk contours have been calculated both for the territory of the terminal and for the neighbouring space. The potential risk for the storage zone is near 10⁻⁴–10⁻⁵ year⁻¹, and at a distance 500 m from the terminal the potential risk values do not exceed 10⁻⁶ year⁻¹. The values of the individual risk for various categories of workers are in the range of 10⁻⁵–10⁻⁶ year⁻¹. Because of low number of the workers on the terminal and large distances to towns and villages the social risk value is negligible. These risk values are consistent with practice of the best oil companies, and fire hazard level of the terminal can be accepted as tolerable.     

Moderation of dust explosions

Inherent safety is a proactive approach to process safety in which hazards are removed or minimized so as to reduce risk without engineered (add-on) or procedural intervention. Four basic principles are available to attain an inherently safer design—minimization, substitution, moderation, and simplification. The subject of the current paper is the principle of moderation as it applies to the prevention and mitigation of dust explosions.

Moderation can be achieved by processing a material under less severe operating conditions or by processing the material in a less hazardous form. With respect to the latter approach, it may be possible to alter the composition of a dust by admixture of solid inertants, or to increase the dust particle size so as to decrease its reactivity. Additionally, avoidance of the formation of hybrid mixtures of explosible dusts and flammable gases is an application of moderation of the material hazard.

Several examples are given for each of the above three forms of moderation. The discussion on admixture of solid inertants includes examples from the following industrial applications: (i) refractory materials manufacturing, (ii) food processing, (iii) power generation, (iv) industrial recycling, and (v) foundry shell mold fabrication. The importance of particle size consideration is explained first from the perspective of engineering tools such as the Dow Fire & Explosion Index, and professional guidance on the definition of a dust and suitable particle sizes for explosibility testing. Industrial examples are then drawn from the following areas: (i) rubber recycling and textile manufacturing, (ii) industrial recycling, (iii) wood processing, (iv) dry additive handling (polyethylene facility), (v) polyethylene production, (vi) carbon block recycling, and (vii) coal mining. The concluding discussion on hybrid mixtures includes brief cases from the process safety literature.     

Ignitability characteristics of aluminium and magnesium dusts that are generated during the shredding of post-consumer wastes

The authors investigated the ignitability of aluminium and magnesium dusts that are generated during the shredding of post-consumer waste. The relations between particle size and the minimum explosive concentration, the minimum ignition energy, the ignition temperature of the dust clouds, etc. the relation between of oxygen concentration and dust explosion, the effect of inert substances on dust explosion, etc. were studied experimentally.

The minimum explosive concentration increased exponentially with particle size. The minimum explosive concentrations of the sample dusts were about 170 g/m³ (aluminium: 0–8 μm) and 90 g/m³ (magnesium: 0–20 μm). The minimum ignition energy tended to increase with particle size. It was about 6 mJ for the aluminium samples and 4 mJ for the magnesium samples. The ignition temperature of dust clouds was about 750 °C for aluminium and about 520 °C for magnesium. The lowest concentrations of oxygen to produce a dust explosion were about 10% for aluminium and about 8% for magnesium. A large mixing ratio (more than about 50%) of calcium oxide or calcium carbonate was necessary to decrease the explosibility of magnesium dust. The experimental data obtained in the present investigation will be useful for evaluating the explosibility of aluminium and magnesium dusts generated in metal recycling operations and thus for enhancing the safety of recycling plants.     

DEVELOPING COMPETITION FOR WATER IN THE URBANIZING AREAS OF COLORADO1

ABSTRACT: Rapid population growth in the metropolitan area of Denver, Colorado, is causing conflicts over water use. Two cities, Thomton and Westminster, have begun condemnation proceedings against three irrigation companies to secure agricultural water rights for municipal use. This is the first condemnation proceeding against irrigation water rights for municipal use. Should the suit succeed, over 30,000 acres of presently irrigated land will lose its water supply. There are about four hundred landowners in the area; two hundred of these are commercial farmers, including truck, dairy and specialty farms. Total agricultural production amounts to about $8 million per year. About 561 jobs related to agriculture will disappear along with about $4 million in not income. Only 6.4 percent of the farmland along the Front Range is irrigated. Continued urban growth will put pressure on the water supply of much of this land. The interested parties of the region should cooperate to lessen the impact of urban growth on agricultural lands and water by forming a metropolitan water district. Such a district could share costs of development of additional municipal water and develop systems where municipalities would recycle waste water back to the irrigated lands.     

PHOSPHORUS ACCUMULATION - DISCHARGE CYCLES IN MARSHES1

ABSTRACT: Artificial and natural marshes were studied to determine changes in quality of polluted water passing through them. Phosphorus removal ranged from zero to 64%. Removals in the 35% range were common, however. Much of the phosphorus went into sediments and unharvestable plant parts. Harvesting vegetation removed 6% of the phosphorus put into the system. Accumulation of phosphorus during the growing season was about 20 g*m^?2, much of which was flushed out after the onset of freezing weather. The amount of phosphorus flushed out can be prevented from entering a lake or stream by handling the marsh discharge in one of three ways; irrigate on land, lagoon to recycle later, treat conventionally if facilities are available.     

EFFECTS OF A RECREATIONAL IMPOUNDMENT ON NEARBY NATURAL LAKES: A CASE STUDY1

ABSTRACT: Completion of a 1270 acre recreational impoundment (Legend Lake) in the glacial sands of Menominee County, Wisconsin, produced geochemical and hydrologic alterations in some nearby natural lakes. The impoundment was produced by the construction of three dams, one of which proved to be temporary, connecting 9 natural lakes and ponds of 383 acres with 951 acres of flooded lands. Water levels were raised 3–15 feet within the impounded area. Much of the flooded area was peat rich wetland associated with the prior drainage. Water depths are less than 15 feet in 70% of the impoundment. Three seepage lakes, located less than 1/2 mile from the impoundment, experienced shoreline flooding, shoreline and soil erosion, some tree kills, and increased turbidity. These lakes also experienced concentration increases in several chemical constituents which indicate an influx of impoundment water through a regional alternation in the groundwater flow paths. The three lakes were connected by canals, and a 2.3 cfs gravity drain with an auxiliary pumping station was built to return excess water to the outflow of the impoundment. Future projects of this type would benefit from a more extensive hydrologic and geochemical analysis prior to initiation. Had environmental assessments been required at the time of this development, as they now are in Wisconsin for similar projects, some of the problems encountered might have been alleviated.     

Public-Health Impact of Outdoor Air Pollution in Russia

Based on the well-known approaches to risk assessment, estimates of the number of attributable deaths caused by atmospheric air pollution in the towns of Russia have been obtained. The data of daily monitoring of air pollution in 1993 and 1998 carried out by Rosgidromet (Weather Service of Russia) were used for assessment. The epidemiology-based exposure–response function for a 10 g/m³ increase in particulate matter PM₁₀ was used to assess the attributable number of cases of deaths in Russia. The EPA approach was applied to derive the risk of carcinogenesis caused by outdoor carcinogens controlled by Rosgidromet. In the present paper, it has been shown that up to 219–233 thousands of premature deaths or 15–17% out of the total annual mortality might be caused by air pollution in Russia. The data are given on a possible contribution of various carcinogens controlled by Rosgidromet at the stations of constant observation to the total mortality caused by atmospheric pollution. On the whole, the number of people that fell ill with cancer as a result of exposure to all the carcinogens present in the atmosphere can be assessed within the range of 2000–4000 humans. This assessment estimates the public-health impacts of air pollution. At the present time, we have no information concerning the degree of universality of the exposure–response function for PM₁₀ and its sensitivity to a change in social-demographic indicators. Nevertheless, the assessments, given in the present work, make it possible to obtain important information concerning the possible scale of health-outcome due to atmospheric pollution for the population of Russia.