Study on riverbank for treating domestic sewage

• Main Authors: Wen-Yen Chang, 張文彥
• Other Authors: Jian-Chuan Shern
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/95686779593735110733

碩士 === 國立高雄海洋科技大學 === 海洋環境工程研究所 === 96 === In this paper, we demonstrate that by treating domestic sewage with natural treatment system ( which called“Sewage-Ecological-Allocation Treatment System, abbr . SEATS ) can dramatically reduce the pollution concentration of river . SEATA ( invented by Dr . Jian-chuan Shem in NKMU ) employing two different models conducted at two adjacent places of same riverbank . one ( named sample area ) is to investigate the coherence and correlation between SEATS and environment by means of SEATS’s own techanology and methodology. The other ( named experiment area ) is aim to evaluate the water quality pollution remove efficiency between surface overland flow and bottom infiltrate flow, and to preliminary figure out the relationship between water pollution remove efficiency and various operating conditions . In sample area, 120-meter square ( 20m * 6m ), laying no impermeable duck, planting local weeds, and limiting inflow up to 120 CMD. However, in experiment area, consisting twelve 12-meter square ( 6m * 2m ) small areas ( total 144-meter square ), laying impermeable duck, growing with cattail, and operating in different situation regarding to inflow ( 2, 4, 6 CMD ), soil thickness ( 30, 50, 70 cm ), water supplying time ( 8, 24 hr / day ) in all small areas . Result from above observations has shown average flow rate of surface increased from 67.54% to 76.44%, average flow rate of bottom decreased to 19.90% from original 24.67% which revealed that bottom infiltrate ability gradually descended with time. Subsequently, individual water quality remove rate and surface average remove rate are as following respectively : -142.26～52.72％（total surface average remove rate 15.28%, COD -23.14～70.31％(30.70%), SS -0.93～66.69％(39.69%), TP -117.46～57.38％(-10.34%), TN-144.08～56.40％( -18.43%), moreover, we obtained the bottom average remove rate below : BOD -115.65～68.85％(total bottom average remove rate 21.45%), COD 44.79～93.16％(61.78%), SS -122.22～63.48％(only 8.96%), TP-3.01～68.32％( 53.03%), TN 11.78～80.48％(52.92 %). Consequentially, from the total remove capacity point of view, we identified that the total pollution remove of surface is superior to the bottom due to its higher surface overland flow. In contrast, from the water quality remove efficiency point of view, the bottom is higher than the surface in spite of its lower overland quantity. In conclusion, under the discussion of different operational conditions, we obtained more consistent result only from different water supply time, which is 8hr is superior to 24hr. However, no obviously accordant result gained in term of different inflow and soi1 thickness. The reason for that is the lower density of inflow pollution water. As a result, SEATE has contributed considerably to the decrease of river’s pollution on a BOD 15％ basis along with short transient time of hydraulic retention at rivethank places. Evidently, SEATS can provide strong attraction to the developing countries by the implementation of replacing cattail with economical crops such as vegetables, flowers or plants.