The Austrian Landfill Ordinance (BGBL 169/96, 1996) sets standards for the types of waste which are allowed to be landfilled. There are limits for total organic compound (TOC), ignition loss (IL), calorific value and many other parameters describing the potential of harmful substances but no parameters checking the biological reactivity of waste. Experimental determination of gas-generating potential is well suited for the assessment of this reactivity because such methods (an incubation test developed by the Austrian Department of Waste Management [ABF-BOKU] ), allow researchers to reproduce the majority of 'natural conditions' in the laboratory. The problem with anaerobic tests is that the period over which the tests run tends to be long, which is why aerobic tests were also carried out. To reduce gas generating potential to less than 10%, a gas generation GS90 ≤ 20 N1 kg-1 dry substance (DS) Nl kg -1 DS is to be maintained. This research shows that the correlating respiration activity AT7 is between 12 and 15 mg O2 g-1 DS.

Municipal solid waste (MSW) was accompanied through a mechanical-biological treatment plant. Over a period of 20 weeks samples were taken at different stages of treatment. Samples were analysed for physico-chemical parameters, reactional behaviour (respiration activity, gas-generating potential) and toxic effects (aquatic toxicity). Results showed that reactional behaviour decreased considerably with the duration of treatment. Gas-generating potential and respiration activity were reduced for more than 90% at the end of the composting process. Total organic carbon (TOC), chemical oxygen demand (COD), biological oxygen demand (BOD 5 ) and ammonia decreased as well. High toxicity could be obtained with the input and short pretreated materials, the output material did not show any toxic effects at all. The results indicate that aerobe treatment of MSW reduces emission behaviour signi®cantly and less reactive waste is left for land®lling.

No abstract

Municipal solid waste (MSW) was accompanied through a mechanical‐biological treatment plant. Over a period of 20 weeks samples were taken at different stages of treatment. Samples were analysed for physico‐chemical parameters, reactional behaviour (respiration activity, gas‐generating potential) and toxic effects (aquatic toxicity). Results showed that reactional behaviour decreased considerably with the duration of treatment. Gas‐generating potential and respiration activity were reduced for more than 90% at the end of the composting process. Total organic carbon (TOC), chemical oxygen demand (COD), biological oxygen demand (BOD5) and ammonia decreased as well. High toxicity could be obtained with the input and short pretreated materials, the output material did not show any toxic effects at all. The results indicate that aerobe treatment of MSW reduces emission behaviour significantly and less reactive waste is left for landfilling.

Many developing countries suffer from a lack of collection, treatment and disposal systems for waste. A laboratory in the Amazon basin of Ecuador took the initiative and tried to handle a rising waste problem itself. Solutions for the recycling, treatment and harmless deposition of chemical wastes were developed and applied. Acidic and basic solutions, representing the majority of chemical residues, were disposed of or added to the waste water system after neutralization. The organic solvents could partly be recovered by rectification; others could be re‐used. Dissolved heavy metals were precipitated and immobilized in concrete. Cyanides were destroyed and residues of microbiological analysis were thermally detoxified, as were oil‐polluted soil samples and irrecoverable organic solvents. Although a description of a particular case, many of these easily applicable solutions could be appropriate for small enterprises or laboratories in a similar situation.