TY - JOUR
T1 - Two-stage removal of nitrate from groundwater using biological and chemical treatments
AU - Ayyasamy, Pudukadu Munusamy
AU - Shanthi, Kuppusamy
AU - Lakshmanaperumalsamy, Perumalsamy
AU - Lee, Soon Jae
AU - Choi, Nag Choul
AU - Kim, Dong Ju
PY - 2007/8
Y1 - 2007/8
N2 - In this study, we attempted to treat groundwater contaminated with nitrate using a two-stage removal system: one is biological treatment using the nitrate-degrading bacteria Pseudomonas sp. RS-7 and the other is chemical treatment using a coagulant. For the biological system, the effect of carbon sources on nitrate removal was first investigated using mineral salt medium (MSM) containing 500 mg l-1 nitrate to select the most effective carbon source. Among three carbon sources, namely, glucose, starch and cellulose, starch at 1% was found to be the most effective. Thus, starch was used as a representative carbon source for the remaining part of the biological treatment where nitrate removal was carried out for MSM solution and groundwater samples containing 500 mg l-1 and 460 mg l-1 nitrate, respectively. About 86% and 89% of nitrate were removed from the MSM solution and groundwater samples, respectively at 72 h. Chemical coagulants such as alum, lime and poly aluminium chloride were tested for the removal of nitrate remaining in the samples. Among the coagulants, lime at 150 mg l-1 exhibited the highest nitrate removal efficiency with complete disappearance for the MSM solutions. Thus, a combined system of biological and chemical treatments was found to be more effective for the complete removal of nitrate from groundwater.
AB - In this study, we attempted to treat groundwater contaminated with nitrate using a two-stage removal system: one is biological treatment using the nitrate-degrading bacteria Pseudomonas sp. RS-7 and the other is chemical treatment using a coagulant. For the biological system, the effect of carbon sources on nitrate removal was first investigated using mineral salt medium (MSM) containing 500 mg l-1 nitrate to select the most effective carbon source. Among three carbon sources, namely, glucose, starch and cellulose, starch at 1% was found to be the most effective. Thus, starch was used as a representative carbon source for the remaining part of the biological treatment where nitrate removal was carried out for MSM solution and groundwater samples containing 500 mg l-1 and 460 mg l-1 nitrate, respectively. About 86% and 89% of nitrate were removed from the MSM solution and groundwater samples, respectively at 72 h. Chemical coagulants such as alum, lime and poly aluminium chloride were tested for the removal of nitrate remaining in the samples. Among the coagulants, lime at 150 mg l-1 exhibited the highest nitrate removal efficiency with complete disappearance for the MSM solutions. Thus, a combined system of biological and chemical treatments was found to be more effective for the complete removal of nitrate from groundwater.
KW - Pseudomonas sp. RS-7
KW - chemical coagulants
KW - groundwater
KW - lime
KW - nitrate removal
UR - http://www.scopus.com/inward/record.url?scp=34548692342&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=34548692342&partnerID=8YFLogxK
U2 - 10.1263/jbb.104.129
DO - 10.1263/jbb.104.129
M3 - Article
C2 - 17884658
AN - SCOPUS:34548692342
VL - 104
SP - 129
EP - 134
JO - Journal of Bioscience and Bioengineering
JF - Journal of Bioscience and Bioengineering
SN - 1389-1723
IS - 2
ER -