IN-SITU BIO-RESTORATION OF AN URBAN WATER POND

摘要

This paper reports the in-situ bio-restoration of the Orchid Garden Pond (the Pond) in the Shanghai Botanical Garden with specific nontoxic enzyme- and micronutrient-based biostimulation products made in the U.S. After elaborate toxicity tests by local authorities and a series of laboratory-scale experiments with water samples from the Pond, the in-situ restoration began in September 2002 and lasted for a month. Given quantities of the enzyme- and nutrient-based liquid biostimulation products were manually sprayed on the water surface weekly to maintain manufacturer-recommended product concentrations in the Pond. Water quality samples from three locations were taken to analyze the variations of BOD_5, COD, NH_3-N, total phosphorous (TP, as PO_4~(-3)), turbidity, dissolved oxygen (DO), temperature, and pH over the restoration period. Water quality analysis and visual inspections revealed that the applied products effectively reduced the concentrations of all selected water quality indices and altered the appearance of the water. Dissolved oxygen levels in two locations were nearly doubled.