ACCUMULATION OF NUTRIENTS AND HEAVY-METALS IN SURFACE SEDIMENTS NEAR MACAO

The effects of water pollution on the accumulation of heavy metals and nutrients in sediments are examined, The contents of arsenic, cadmium , chromium, lead, total nitrogen and total phosphorus compounds in bot h aquatic and sediment phases are presented, The spatial distributions of sediment pollution are not completely dependent on the correspondi ng aquatic conditions, The enrichment of phosphorus in sediments is mo re obvious than that of nitrogen compounds, The content ratio of total phosphorus between two phases reaches 13 000, Although the concentrat ions of heavy metals in aquatic phase are low, due to the large conten t ratios which are, respectively, 9500, 14 000, 11 000 and 4600 for ar senic, cadmium, chromium and lead, their accumulations are significant , Among the four sediment fractions of different sizes (diameters: >0. 125 mm, 0.063-0.125 mm, 0.045-0.063 mm and less than or equal to 0.45 mm), the contents of heavy metals are generally higher in the fraction s of 0.045-0.063 mm and 0.063-0.125 mm. (C) 1996 Elsevier Science Ltd