Reclamation of wastewater for polyculture of freshwater fish: bioassays using Chlorella and Gambusia.
The feasibility of using the secondary effluents from two sewage treatment plants in Hong Kong (Yuen Long and Shek Wu Hui) for fish culture was assessed. Total ammonia contents in the two sewage effluents surpassed the level of 2 mg L(-1) recommended for wastewater fish culture. The two sewage effluents both needed essential elements for supporting algal Chlorella vulgaris growth, whereas only sewage effluent from Yuen Long had contaminants at toxic levels. Total ammonia in water explained more than 80% variations of toxicity of water samples to Gambusia patruelis, mosquito fish, according to regression analysis. Removal of ammonia from the sewage effluent is necessary before being used for fish culture. In addition, the rather high levels of heavy metals (Cu, Zn, Cd) in the effluent should be closely monitored.
Liang
Y
Y
Institute for Natural Resources and Waste Management and Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong, P. R. China.
Wong
M H
MH
D000641:Ammonia / Q000032:analysis; D000818:Animals; D017756:Aquaculture; D002708:Chlorella / Q000187:drug effects* / Q000254:growth & development; D003532:Cyprinodontiformes / Q000254:growth & development; D005240:Feasibility Studies; D006723:Hong Kong; D007928:Lethal Dose 50; D019216:Metals, Heavy / Q000032:analysis; D012722:Sewage; D018675:Toxicity Tests; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*; D018508:Water Purification
D019216:Metals, Heavy; D012722:Sewage; D014874:Water Pollutants, Chemical; D000641:Ammonia