The Israeli Journal of Aquaculture Bamidgeh 56(3), 2004, 166-175

EFFECTS OF ALUM ON THE QUALITY OF AQUACULTURE 
EFFLUENTS IN SETTLING PONDS  


Martha Rowan1, Amit Gross2* and Claude E. Boyd3

1 Department of Zoology, 207 Research Station Road, North Carolina State University, 
Plymouth, North Carolina 27962, USA 

2 Department of Environmental Hydrology and Microbiology, Institute for Water Sciences 
and Technologies, Jacob Blaustein Institutes for Desert Research, Ben Gurion University 
of the Negev, Sde Boker Campus, 84990 Midreshet Ben Gurion, Israel

3 Department of Fisheries and Allied Aquacultures, Auburn University, Auburn, 
Alabama 36849, USA

(Received 3.4.04, Accepted 22.4.04)

Key words: alum, pollutants, settling ponds 


Abstract

The effectiveness of alum (aluminum sulfate) in reducing the concentrations of potential pollutants in pond effluents was investigated in catfish production ponds. Application of alum at 50 mg/l to water remaining in ponds immediately after seining for harvest did not generally result in significantly greater removal of nutrients and solids than did settling alone, although removal rates of some variables were initially higher in the alum treated ponds. Within four hours of seining in both alum treated and untreated ponds, there was removal of more than 85% of total suspended solids, 75% of total phosphorus, 72% of turbidity, and more than 40% of biochemical oxygen demand and chemical oxygen demand. Concentrations of soluble reactive phosphorus decreased after 48 h, but total ammonia nitrogen was not removed. Alum may be more effective in improving water quality in settling ponds if it is applied after the initial sedimentation has occurred. 


* Corresponding author. E-mail: amgross@bgumail.bgu.ac.il

home