ISSN:
1432-0495
Keywords:
Keywords Acid-drainage
;
Bioremediation
;
Sewage
;
Sulphate-reducing-bacteria
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
Notes:
Abstract Effects of a clay-lime spiked sewage sludge and fresh decomposable ryegrass on the mitigation of an acid drainage were studied in the laboratory. Treatments (dry ameliorant weight/leachate ratio) were: (1) sludge (air-dried) at rates of 0, 8, 16 and 24%, (2) ryegrass at 0, 1, 1.5 and 2% (dry weight), (3) sludge (at the above-mentioned rates) and 1.5% ryegrass mixture. Measurements of mitigation (according to the criteria of changes in pH, Fe, S, Al and heavy metals) made every 10th day for 100 days showed ryegrass/sludge combination the most effective while sustaining mitigation longest, with or without the influence of sulphate-reducing bacteria (SRB). Sulphate and Fe in the acid drainage decreased in the order: sludge+ryegrass〉sludge〉ryegrass by 180, 40, 19; and 96, 83 and 54% respectively, compared with controls. An 11-fold decrease in soluble Al was caused by the highest rate of the combined sludge-ryegrass treatment but Al was doubled by the sludge-only treatment, and only minimally affected (2% reduction) by the ryegrass-only treatment. For the sludge plus ryegrass treatments at the highest rate of application, pH levels increased significantly, from 2.3 to 〉7 units and within 20 days of SRB activation, the concentration of Co, Cu, Mn, Ni and Zn decreased 3-, 15-, 90-, 3- and 50-fold respectively.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s002540000138
