The response of the ocean redox state to the rise of atmospheric oxygen about 2.3 billion years ago (Ga) is a matter of controversy. Here we provide iron isotope evidence that the change in the ocean iron cycle occurred at the same time as the change in the atmospheric redox state. Variable and negative iron isotope values in pyrites older than about 2.3 Ga suggest that an iron-rich global ocea...

A pot experiment was conducted to examine the effects of.various fertilizers on the dynamics of soil-borne DDTs and their subsequent impacts on DDTs uptake by a test plant. The results show that there was a significantly lower soil residual DDTs concentration in the iron-rich fertilizer-treated soil than in other fertilizer-treated soils. However, all the non-iron-rich fertilizers showed no sig...

The potential for reuse of iron-rich sludge from waterworks as a replacement for commercial iron salts in wastewater treatment was investigated using acidic and anaerobic dissolution. The acidic dissolution of waterworks sludge both in sulphuric acid and acidic products such as flue gas washing water and commercial iron solution was successful in dissolving the iron from waterworks sludge. The ...

Vegetarians who eat a varied and well balanced diet are not at any greater risk of iron deficiency anaemia than non-vegetarians. A diet rich in wholegrains, legumes, nuts, seeds, dried fruits, iron-fortified cereals and green leafy vegetables provides an adequate iron intake. Vitamin C and other organic acids enhance non-haem iron absorption, a process that is carefully regulated by the gut. Pe...

Mercury contamination associated with small-scale gold mining and processing represents a major environmental and human health concern in Eastern and Southern Africa. Approximately 200,000-300,000 persons are involved in small-scale gold mining activities in Tanzania and > 200,000 persons in Zimbabwe. Mercury (Hg) is used mainly for the processing of primary gold quartz veins and supergene gold...

implications for the crystallization method of the metallic cores. In order to match observed P values in iron meteorites, the core must crystallize in the presence of the P-rich liquid. The composition of the S-rich liquid, dictated by the liquid immiscibility field, hasP contents much too low to reproduce P trends of iron meteorites. This suggests that inward core crystallization from the cor...

In this study, results of the crystallization of iron-rich glasses are summarized. Thermogravimetry (TG)±di€erential thermal analysis (DTA) were utilized to explain the phase formations and the surface oxidation of FeO to yield Fe 2 O 3. The crystal phases fraction was evaluated utilizing X-ray di€raction analysis (XRD). Low angle XRD technique was used to investigate the distribution of the cr...

The extreme osmotic conditions prevailing in hypersaline environments result in decreasing metabolic diversity with increasing salinity. Various microbial metabolisms have been shown to occur even at high salinity, including photosynthesis as well as sulfate and nitrate reduction. However, information about anaerobic microbial iron metabolism in hypersaline environments is scarce. We studied th...