The use of the cotton-strip assay to assess cellulose decomposition in heavy metal-contaminated sewage sludge-amended soils

Sewage sludge is an effective fertilizer in many soil types. When applied as an amendment, sludge introduces, in addition to organic matter, plant nutrients into the soil. When applied for cropland as a fertilizer, the mass loading of sewage sludge is customarily determined by inputs of N and/or P required to support optimal plant growth and a successful harvest. This study aims to examine the changes in organic matter contents and nitrogen forms in sludge-amended soils, as well as the growth of corn and faba bean plants. The main results indicated that there were higher responses to the corn and faba bean yields when sludge was added. Levels of organic carbon in soil were higher after maize harvest and decreased significantly after harvesting of beans, and were higher in sludge amended soils than unmodified soils, indicating the residual effect of sludge in soil. NO3−-N concentrations were generally higher in the soil after maize harvest than during the plant growth period, but this trend was not apparent in bean soil. The amounts of NH4+-N were close in the soil during the growth period or after the maize harvest, while they were higher in the soil after the bean harvest than they were during the growth period. Total nitrogen amounts were statistically higher in the soil during the growth period than those collected after the corn harvest, while they were approximately close in the bean soil. The total nitrogen amount in corn and bean leaves increased significantly in plants grown on modified sludge soil. There were no significant differences in the total nitrogen levels of the maize and beans planted on the treated soil.

Download Full-text

Effects of digested sewage sludge on yield and heavy metal accumulation in horticultural species

Bioresource Technology ◽

10.1016/0960-8524(93)90123-s ◽

1993 ◽

Vol 46 (3) ◽

pp. 217-220 ◽

Cited By ~ 5

Author(s):

Giuseppe Cimino ◽

Giovanni Toscano

Keyword(s):

Heavy Metal ◽

Sewage Sludge ◽

Metal Accumulation ◽

Heavy Metal Accumulation ◽

Digested Sewage Sludge

Download Full-text

Inhibition of methanogenesis in pure cultures by ammonia, fatty acids, and heavy metals, and protection against heavy metal toxicity by sewage sludge

Canadian Journal of Microbiology ◽

10.1139/m87-093 ◽

1987 ◽

Vol 33 (6) ◽

pp. 551-554 ◽

Cited By ~ 71

Author(s):

Ken F. Jarrell ◽

Michelle Saulnier ◽

Art Ley

Keyword(s):

Heavy Metals ◽

Fatty Acids ◽

Heavy Metal ◽

Sewage Sludge ◽

Metal Toxicity ◽

Heavy Metal Toxicity ◽

Methanosarcina Barkeri ◽

Methanospirillum Hungatei ◽

Nickel Zinc ◽

Pure Cultures

The effect of ammonium chloride, sodium butyrate, sodium propionate, and the heavy metals nickel, zinc, and copper on methanogenesis by pure cultures of Methanospirillum hungatei, Methanosarcina barkeri, Methanobacterium thermoautotrophicum, and Methanobacterium formicicum at pH 6.5 was studied. The latter three strains were resistant to > 60 g/L of the volatile fatty acids and to > 10 g/L of NH3 N. Methanospirillum hungatei was somewhat more sensitive with 50% inhibition of methanogenesis occurring at 4.2 g/L NH3 N, 27 g/L butyrate, and 41 g/L propionate. All strains were very sensitive to both copper (1–5 mg/L) and zinc (1–10 mg/L), but much more resistant to nickel. Zinc and copper concentrations 30 to 270 times higher were required to cause inhibition of Msp. hungatei incubated in sewage sludge compared with buffer, indicating a strong protective environment was afforded the methanogens against heavy metal toxicity in the sludge.

Download Full-text