A high loading overland flow system: Impacts on soil characteristics, grass constituents, yields and nutrient removal.

The objectives of this paper are to determine effects of different grass species and their harvests on pollutant removal, elucidate impacts on soil characteristics and grass constituents, observe grass yield and quantify nutrient uptake by vegetation in an overland flow system (OLFS). Polluted creek water was applied to eight channels in the OLFS, which were planted with Paragrass, Nilegrass, Cattail, and Vetiver, with each two channels being randomly planted with a given grass species. The grass in one channel was harvested while that in the other channel was not. At a high rate of 27.8 m d(-1) hydraulic loading, the removal efficiencies of conventional pollutants such as BOD, COD, suspended solids (SS), and total coliforms in wastewater are not affected by the type of the grasses species, but those of nitrogen and phosphorus are affected by different species. Overall average removal efficiencies of BOD, COD, SS, ammonia, total nitrogen, total phosphorus and total coliforms through the OLFS are 42%, 48%, 78%, 47%, 40%, 33% and 89%, respectively. The concentration of nitrate, however, increases due to nitrification. Soil characteristics in OLFS have been changed significantly; specific conductivity, organic matter, exchangeable magnesium, extractable copper and zinc in soils all increase with time while pHs decrease. During the winter season, there is a significant accumulation of nitrate in grass with the subsequent reduction during the active growing season (Spring). The contents of nitrate and phosphorus in grass tissue are higher than those of grass in general pastureland, probably due to nutrient luxury uptake by grass. The overall grass yield, growth rate and nutrient uptake are quantified and implication of such high rate OLFS discussed.

[Significance of the serum level of Cu, Zn, Mn, Cr and Ni in acute leukemia].

Serum Cu and Ni increase, while serum Zn and Mn decrease in acute leukemia patients. The results of this study showed that there is correlation between the change of the level of serum Ni and the condition of the patient. Higher level of serum Ni in patients with acute leukemia indicates inefficient chemotherapy and poor prognosis. The results suggest that the level of serum Ni may be used as an in acute leukemia. Increase of serum Ni with simultaneous decrease of serum Mn may be an instinctive reflection in acute leukemia.