Determination of chlorine and bromine in automotive shredder residues by oxygen bomb and ion chromatography
An analytical procedure, oxygen bomb combustion-ion chromatography (IC), has been developed for the determination of total chlorine in Automotive Shredder Residues (ASR). Samples of these residues are fired under elevated oxygen pressure (30 atm) and the combustion products are transferred into a Na2 CO3/NaHCO3 absorbent solution containing 1% of H2 O2; the chlorine contents are then evaluated by ion chromatography. The use of the non-suppressed IC determination with a conductivity detector provides a rapid, sensitive and selective method for chlorine determination in ASR, allowing determinations of this heteroatom at levels below 1% in the presence of bromine and sulfur. Moreover, the proposed method allows the simultaneous determination of chlorine, bromine and sulfur which are potential environmental hazards.
Physical and Chemical Characterization of Automotive Shredder Residues
Car manufacturers recycle many of the materials from wrecked vehicles, but the disposal of the lighter components is increasingly difficult. The high cost of landfill is making the option of incineration more attractive, as it reduces the mass and the volume of the waste. Energy recovery is also possible. This paper examines those properties of automotive shredder residues (ASR) which are relevant to the formation of pollutants during incineration. The higher specific energy of ASR was found to be 19,000 kJ kg 1 and the ash content 38%, which indicate that it is a suitable fuel for municipal incinerators or cement kilns. However, it is very heterogeneous, as the low density fraction is mainly composed of plastics, with smaller amounts of metallic pieces, rubber, glass and wood. The macroscopic composition of a representative sample of ASR was determined. The metal and the chlorine contents were analysed by special techniques and were found to be 22% and 3.5%, respectively of the fraction. Laboratory-scale incineration trials of ASR are now planned. © 1997 ISWA
Complexometric titration of phosphorus in organic compounds
ZusammenfassungDie Probe wird im Sauerstoffkolben nach Schöniger verbrannt und der Phosphor als Cer(III)-phosphat ausgefällt. Der Überschuß an Cer(III) wird bei pH 6–7 mit ÄDTA zurücktitriert, wobei Methylthymolblau oder Xylenolorange als Indicator dient. Als Absorptionsmittel wird alkalische Hypobromitlösung verwendet. Um eine vollständige Verbrennung zu gewährleisten, ist es wichtig, daß das Papier mit der Probe fest am Platinhalter angeklammert wird.SummaryA new complexometric method for the determination of phosphorus in organic compounds is described. After combustion in an oxygen-flask, phosphorus is precipitated as cerous phosphate. The excess cerous ion is back-titrated at pH 6–7 with EDTA in the presence of methylthymol blue or xylenol orange indicators. Alkaline hypobromite is used as an absorbent. Tight clamping of the paper carrier in the platinum holder insures complete combustion.