| Title |
Effects of Application Method , Hydraulic Loading Rate and Soil Texture on Organic Removal in a Soil Trench System |
| Authors |
원종철 ; 남궁완 ; 임연택 ; 윤조희 ( Jong Chul Won ; Wan NamKoong ; Yeon Tack Rim ; Cho Hee Yoon ) |
| Abstract |
The role of trench in soil trench systems treating septic tank effluent was evaluated in the laboratory. Parameters investigated were the waste application method (application with rest period versus continuous application), hydraulic loading rate (100 ℓ/m ·day versus 200ℓ/m day) and soil texture (Sandy Loam versus Sand). Experimental reactors (60㎝ high by 40㎝ wide by 5㎝ thick) were constructed so that two dimensional distribution of bacteria and volatile solids in the trench could be examined. TOC concentrations in the effluent from the reactors with continuous application of wastewater were lower than those from the reactors with rest period. However, the wastewater infiltration rate with continuous application of wastewater was lower than that with rest period implying possible clogging problem in the near future. TOC removal efficiency was over 80% for both systems. TOC concentration in the effluent from the reactor with 200ℓ/m day hydraulic loading rate was much higher than that from the reactor with 100ℓ/m day. The average TOC removal efficiency at 200ℓ/m day was only 63%, while that at 100ℓ/m day was 81%. TOC concentration in the effluent from the reactor packed with sandy loam was similar to that of the reactor packed with sand. Bacteria were high in number near the infiltration surface of wastewater in the trench. Volatile solids were distributed relatively evenly in the trench. There was no direct relationship between the number of bacteria and volatile solids in the soil. |