Response of microbial activities in two contrasting soils to 4-nonylphenol treated with biosolids.
In the application of biosolids on agricultural lands, 4-nonylphenol (4-NP) in soils is an important environmental concern because of its associated estrogenic risk to animals and human beings. Incubation experiments that involved the mixing of two contrasting soils (A: calcareous sandy soil; B: acidic clayey soil) and biosolids in 4-NP were performed to examine the effect of 4-NP on the rate of production of CO2, the mineralization of N and the microbial biomass, by considering the biodegradation of 4-NP for the evaluation of soil health. The experimental results indicated that the half-life (t1/2) of 4-NP increased with the supplementary concentration of 4-NP (80, 160 and 240 mg kg(-1)) in the two soils, and the t1/2 values in the soil A are always lower than that in soil B. The 4-NP supplement in the biosolids reverses C mineralization in soil B more than it does in soil A, but it reverses N mineralization in soil A more than in soil B. The aeration status and microbial population of the biosolids treated soils are key factors in determining the time course of 4-NP degradation associated with the microbial activities. The 4-NP was biodegraded mainly by bacteria, and the effect on C and N mineralization of 4-NP input is determined by a balance of the reductions in microbial biomass C (MBC) and N (MBN). After destruction in microbial cell membrane and protein structures by the 4-NP, C and N mineralization, MBC and MBN were subsequently followed by a final decline phase for the later period of incubation.
Hseu
Zeng-Yei
ZY
Department of Environmental Science and Engineering, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan. zyhseu@mail.npust.edu.tw
D001673:Biodegradation, Environmental; D018533:Biomass; D002244:Carbon / Q000378:metabolism; D052244:Endocrine Disruptors / Q000378:metabolism / Q000494:pharmacology*; D006207:Half-Life; D009584:Nitrogen / Q000378:metabolism; D010636:Phenols / Q000378:metabolism / Q000494:pharmacology*; D012988:Soil Microbiology
D052244:Endocrine Disruptors; D010636:Phenols; D002244:Carbon; C041594:4-nonylphenol; D009584:Nitrogen