Aquaculturists face a growing problem of decreasing water quality. Pollution causes negative feedback on yields and profits. Sludge accumulation is a common problem in aquacultural production. The sludge is not only expensive to get rid of but also contributes to degrading water quality and can cause poor flesh flavour. The Bacta-Pur System was developed as an ecological engineering tool to contribute to sustainable aquaculture and profitability.

A trout pond in Ontario, on one of the largest fishing preserves in Canada was having a problem with sludge accumulation. The pond in question was about 120 ft x 90 ft x 15 ft deep and is used for fishing but also receives hatchery wastes. Approximately, two feet of trout manure accumulated in the pond each year. Vacuuming out the ponds was not only time consuming but also simply put the wastes elsewhere. The owner wanted to reduce the sludge handling time and costs and to improve water clarity.

Intensive production of livestock such as chickens or pigs usually results in high levels of airborne ammonia. The degraded air quality stresses the animals, causes negative feedback on the production including decreased efficiency of food conversion and increased susceptibility to general diseases and specifically to pulmonary problems (e.g. pneumonia).

The bottom line is fundamental in all animal production: More Stress = Less Profits. Alternatively, if we can decrease stress, we can increase profits.

Treatment Program The ability of the Bacta-Pur System to lower airborne ammonia was tested over a period of 38 days in an egg producing facility in New Brunswick, Canada. The barn (15m x 45m) contains 12,000 chickens. The barn is cleaned in September, and air degrades over winter. This winter ammonia reached levels, which were causing the chickens to go blind. The treatment with Bacta-Pur began on May 15, 1995 for 4 weeks. Airborne ammonia was monitored with a Dräger tester as used by the government of New Brunswick. The air sampling, during and following the test period, was always conducted in the same place within the barn. Five litres of Bacta-Pur XLG were mixed with 10 L of water and sprayed, with a small garden backpack sprayer, onto the manure 3 times per week for 3 weeks . The fourth week, Bacta-Pur was applied only once. Results Airborne ammonia dropped from nearly 60 ppm to 18 ppm, within 3 weeks of beginning the treatment. Ammonia levels only increased slightly to 25 ppm with the decreased rate of use of Bacta-Pur. Cessation of use of Bacta-Pur, however, resulted in the rapid return to ammonia levels above 40 ppm in spite of increased ventilation, in the end of June, as normally occurs in summer.

A demonstration was conducted, in Holland, to reduce BOD and ammonia and odors in pig waste. 10,000 liters of wastes were presettled; the liquid phase was then separated, aerated and treated with the Bacta-Pur System.

One liter (100 ppm) of Bacta-Pur G-2000+ was initially preactivated and added; this was followed by daily additions of 20 ml (2 ppm). BOD decreased from nearly 5000 mg/L, at the start, to 350 mg/L within 2 weeks. The lack of data between these sampling points did not allow determination of the true rate of decrease. Ammonia-nitrogen decreased from 2000 mg/L to 100 mg/L over the 39 days of the trial. Further reductions would have been anticipated had Bacta-Pur N-2000+ also been included in the treatment.

(Since the time of this demonstration, G-2000+ has been replaced by Bacta-Pur XLG, which is more than 1000 times more concentrated. Also, since this study , N-2000+ has been replaced by Bacta-Pur N-3000, which is more than 1000 times more concentrated.)