SOME PROBLEMS OF WASTE MANAGEMENT IN DEVELOPING
COUNTRIES
University of the Witwatersrand
There is a growing concern for the inadequacies of solid waste management in developing countries, and developing areas of countries with mixed economies. The reasons for waste collection and sanitary disposal and the technology of landfilling is well-understood and accepted in developed countries, and workable regulations are now in place in most developed lands. However, waste disposal in developing countries is still largely uncontrolled and large quantities of waste go uncollected. There is a need to recognise the difficulties experienced in managing waste in developing areas and to understand the reasons for those difficulties. This paper briefly over-views the situation and makes recommendations for future directions of research and action. Keywords: Waste management; developing areas; waste composition; scavenging; reclaiming; graded standards; landfilling
AN EXPERIMENTAL ASSESSMENT OF GREENWASTE*
COMPOST FOR HORTICULTURAL APPLICATIONS
D.M. Grehan
Department of Agricultural and Food Engineering
Composting of waste is one option currently being utilised internationally to beneficially reuse waste. An experiment was carried out in the Dublin region to assess the use of greenwaste compost in horticultural applications. The waste comprising mainly of parks waste, and garden waste deposited at civic amenity sites, was collected and shredded to form a trapezoidal windrow which reached maturation in March 1993. Samples were taken and initially subjected to a sieve analysis to determine the particle size profile of the compost. Growing trials using lettuce and tomato plants with potting peat as the control substrate were carried out under controlled conditions at the university's greenhouses. Both chemical and physical analyses of the mixes were carried out at regular intervals, in tandem with continuous monitoring of plant performance. The plants grown in mixes containing greenwaste compost did not meet basic requirements for plant yield as set by European standards. Plants sown in the compost were not as succulent as those sown in the control substrate with average percentage dry matters of 17% and 8% respectively. The compost was lacking in nitrogen and phosphorus and had excessive potassium in comparison to the control substrate. Results of heavy metal analyses showed that the compost may be categorised as a class II compost (clean compost) according to German and American standards. The use of the compost in conjunction with potting peat was recommended as the true value of the compost is in the organic matter and microbial activity it imparts and these properties will promote healthy plant growth through increased tilth and water holding capacity. Key words: Greenwaste; Compost; Growing Trial; Horticulture
DRAINAGE PIPE FROM SCRAP TRUCK TIRES
School of Civil Engineering and Environmental Science
J.L. Gattis Mack-Blackwell Transportation Center
Ben Wallace School of Civil Engineering and Environmental Science
ABSTRACT Truck-tire pipes are made by cutting the bead and sidewall from 40 heavy truck tires. Eighty bead/sidwalls are stacked, compressed to eight feet (2.4 m), and held in place with #3 rebars wrapped length-wise around the pipe walls at 90 degree intervals and welded. The goal of this paper is to evaluate the truck-tire pipe in drainage applications using site inspections, experimental tests, and theoretical analyses. Truck-tire pipes have both advantages and limitations compared to conventional drainage pipes. Parallel plate loading tests indicate that truck-tire pipes meet stiffness requirements. In fact, truck-tire pipes maintain acceptable stiffness over a wide range of deflection. Corrosion analysis of pipe rebars indicates that the pipes may have long lifetimes, even in corrosive soils. The main limitations are the higher cost of installation and the potential for soil erosion through joints. The later problem can be addressed by carefully installing joint wrap and, perhaps, using a wider wrap. Key words: Scrap tires; Tires; Culverts; Pipes; Reuse; Pipe stiffness
DRY-CELL BATTERY HEALTH AND ENVIRONMENTAL
HAZARDS AND DISPOSAL OPTIONS
Raymond A. Shapek University of Central Florida
ABSTRACT Nearly every state, including the District of Columbia has passed some type of solid waste management law. Thirteen states have included laws to reduce landfill contamination by restricting the amount of mercury and cadmium entering the waste stream through dry-cell (household) battery separation or collection programs. Household (HH) batteries contribute 52 percent of the cadmium and 88 percent of all mercury found in the municipal solid waste, yet comprise less than 1 percent (by weight) of municipal solid waste. The public is generally unaware of the potential health and environmental risks of unrestricted disposal of dry-cell batteries and local officials are reluctant to initiate collection programs because of the high-costs and subsequent disposal costs of collected cells. This article assesses the potential health and environmental risks of the unrestricted disposal of household batteries, the collection and available disposal options, and concludes with several recommendations for communities considering initiating HH battery collection/recycling programs. |
