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Preface
Table
of Contents
Foundation
Hybrid
Lagoon System
Case
Study
Applications
Proposals
17.
Evaluation of Hybrid Lagoon Performance
(1) Environment
Division, Department of Shiga prefecture Denitrification Tests.
1982.
Photo
7. "HLS" for the function examination.
Shiga Prefecture is enforcing regulations on nitrogen and phosphorus contents of wastes in order to prevent eutrophication of Lake Biwa. These tests were conducted to evaluate the performance of hybrid lagoon automatic control systems in processing household wastewater. Facilities were constructed within the? Shiga Prefecture Breeding Stock grounds, located in Hinomachi, Shiga Prefecture, and tests were conducted from December 1982 to May 1983. (Cf. Photo 15 and 341-347 of text)
Table
1:
May 13, 1983, results of analyses of water samples,
Conducted by Hiyoshi Welfare Work Company, Shiga Prefecture.
|
Component |
Unit |
flow-in |
|
flow-out |
remove |
|
Appearance |
|
Gray |
clear |
clear |
|
|
Oder |
|
Corrupt |
oderless |
scentless |
|
|
Transparency |
|
<1 |
>30 |
>30 |
|
|
Chloride ion |
|
652 |
424 |
409 |
|
|
pH |
|
7.00 |
6.21 |
6.80 |
|
|
BOD |
mg/l |
1,000 |
1.0 |
4.0 |
99.6% |
|
COD |
mg/l |
361 |
5.9 |
6.6 |
96.3% |
|
SS |
mg/l |
320 |
10 |
|
96.0% |
|
NH3-N |
mg/l |
171 |
0.6 |
1.2 |
99.6% |
|
NO2-N |
mg/l |
0.26 |
0.04 |
0.22 |
|
|
NO3-N |
mg/l |
0.50 |
0.80 |
3.60 |
|
|
Kj-N |
mg/l |
212 |
0.70 |
1.80 |
99.4% |
|
T-N |
mg/l |
212 |
5.70 |
5.80 |
97.4% |
|
T-P |
mg/l |
6.3 |
0.4 |
0.4 |
98.3% |
MLSS 3,900mg/l. MLVSS 3,100mg/l. SV-30 95%
Results of the evaluation indicated that the high-level processing functions anticipated were obtained, without addition of carbon sources and while exercising control over the aeration. Olume, despite the fact that the concentrations of impurities in the water to be processed exceeded the design levels. The results of these tests have been published in the 1982-1983 Shiga refectory White Paper on the Environment.
Results of surveys of final processing performance are as follows. (May 13, 1983, results of analyses of water samples, conducted by HIroshi Welfare Work Company, Shiga Prefecture)