The results of model calculations carried out to identify and quantify the input pathways of trace elements into cement and concrete and to estimate the extent to which trace element concentrations in cement may change due to waste utilization are presented. As expected, primary raw materials represented the most important input pathway for trace elements into cement, but the contribution from wastes was not negligible. The use of waste led to a slight increase of the concentrations of cadmium, antimony and zinc in cement. For cobalt, lead and vanadium, this increase was less distinct and for all other trace elements considered, the effect of the use of wastes on trace element concentrations in cement could not be demonstrated clearly. The trace element content of concrete was governed by the aggregates for most elements considered. However, for arsenic, cadmium, lead and zinc, both cement and the additive coal fly ash contributed noticeably to the total trace element concentration in the concrete.

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Farblose Ionenkristalle des Carbonyl‐kupfer‐Komplexes [(NH3)3(CO)Cu][Co(CO)4] (1 a) entstehen bei der Reaktion von [Cu(NH3)4]Cl und Na[Co(CO)4] (T < − 8°C, 1 bar CO‐Druck); oberhalb −5°C und unter N2‐Atmosphäre entsteht aus 1 a [(NH3)2CuCo(CO)4] (C), von dem ausgehend weitere Cobaltate zugänglich sind: Die Amine N‐Amino‐piperidin, N,N‐Dimethyl‐ethylendiamin (dmed) und N‐Benzyl‐N′,N′‐dimethyl‐ethylendiamin (bn‐dmed) verdrängen NH3 unter Erhalt der CuCo‐Bindung zu [(C5H10NNH2)3CuCo(CO)4] (1 b), [(dmed)CuCo(CO)4] (1 c), [(bn‐dmed)CuCo(CO)4] (1 d). Das zu C isostere [(NH3)2CuFe(CO)3NO] (2 a) entsteht bei der Reaktion von [Cu(NH3)4]Cl und Na[Fe(CO)3NO] in wäßriger Lösung; mit N,N,N′,N′‐Tetramethylethylendiamin (tmed) wird aus 2 a [(tmed)(NH3)CuFe(CO)3NO] (2 b) erhalten. Mit dem [Mn(CO)5]−‐Ion bildet sich dagegen unter den für 2 a angegebenen Reaktionsbedingungen der ammoniakärmere, heteronukleare Vierkerncluster [{(NH3)CuMn(CO)5}2] (3). Alle neuen Verbindungen sind durch Einkristallstrukturanalyse gesichert.

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with potassium carbonate in methanol. Compound 10cr7] was obtained as a mixture of four stereoisomers, since the phosphorus atom is also a stereogenic center and the phosphorylation with 9 proceeded, as expected, in a nonstereoselective fashion. All the compounds reported here are very acid labile, so that chromatography is only possible in the presence of triethylamine.The stereochemistry of 1Oc at the anomeric center is revealed by the doublet for 1-H at 6 = 4.53 (J = 8 Hz) in the 'H NMR spectrum.[*] The configuration at C-2' is assigned on the basis of the I3C NMR signals for C-1' and C-3'. We assume that, by analogy to the NMR datac4] for the acetal glycosides of aldehydes, the signals in the spectrum of the (2'R) epimer lie at lower field for C-I' and higher field for C-3', compared to the corresponding signals of the (2's) isomer.The kinetics of the acid-catalyzed hydrolysis[91 of 1Oc was determined using NMR spectroscopy. The first-order rate constant for deuterolysis at pD = 6.10 in phosphate buffer at 35 " c (0.10 M,Assuming a kDm/kH, value of 1 .5,['01 1Oc has a half-time for hydrolysis of 15 h at pH = 6.2 and 35 "C. This value roughly corresponds to the desired value. Cleavage of 1Oc yields besides glucose and methanol, the diamidophosphate 11 (ketophosphamide)," 'I which, via either elimination or hydrolysis, is converted into the cytotoxic phosphoramide mustard 12 in the cell. This compound is also the active metabolite of the clinically used cytostatic drug cyclophosphamide. [' 21

Summary Material flows of the economic cycle can contain toxic substances, which enter the economy as impurities in raw materials or are intentionally added as minor or even main constituents during the manufacture of industrial or consumer goods. Cadmium, predominantly associated with zinc minerals, is a by‐product of the primary zinc production. Cadmium is generated when zinc is extracted from zinc ores and concentrates, an intermediate product resulting from flotation processing after the zinc ore has been mined and milled. Information on the amount of cadmium generated from zinc extraction is rarely published. In this article, we assess generation and fate of cadmium accumulating worldwide in the production of primary zinc from ores and concentrates. Model calculations for the beginning of the 21st century show that annually about 30,000 tonnes of cadmium were generated, but only approximately 16,000 tonnes were converted to primary cadmium metal, key material for the production of other cadmium compounds (e.g., cadmium oxide), and cadmium‐containing goods (e.g., nickel−cadmium batteries). Hence, about 14,000 tonnes of cadmium must have been transferred somewhere else. The fate of about 5,500 tonnes can be plausibly explained, but it is difficult to determine what happens to the rest.

Cement is a mass construction material with large world-wide growth rates. At present its production contributes approximately eight percent of all global CO2 emissions (excluding the emissions caused by land use, land use change, and forestry). The cement industry has adopted many measures to reduce these emissions, such as technical improvements or use of secondary materials. In this article, it will be shown that these measures are not sufficient to stabilise or lower future CO2 emissions. CCS (Carbon Dioxide Capture and Storage) is currently being discussed for further improvements in reducing CO2 emissions. However, instead of focussing on this end of pipe technology, which has not yet been realised at cement plants, the development of low-CO2 cements produced with substantially lower CO2 emissions would be a more sustainable course provided these innovative cements have the potential to replace conventional cement.

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