Control of Water Pollution by Natural Wastewater Treatment in Streams

ABSTRACT: This study aims to prevent excessive pollution and conservation of biodiversity in over-polluted Ni？de Creek feeding Akkaya lake. Therefore, a pilot-scale hybrid natural wastewater treatment (NWT) system was constructed at edge of the stream in 2014. The system consisted of settling basin (SB), followed by a free water surface constructed wetland (FWS-CW) and overland flow (OF) bed was fed with contaminated waters of creek. Water samples were collected for temperature, pH, dissolved oxygen (DO), and biochemical oxygen demand (BOD) analysis from 6 different stations chosen in the creek and the lake, and the inputs and outputs of the system. According to the study results, the BOD concentrations in the creek and lake showed significant changes during operation period. While the BOD concentration in the lake was not much affected by the seasonal changes, the BOD concentrations in the creek were higher in the warmer seasons. The study results indicated that the creek was over-polluted due to high organic matter input, and lake became eutrophic. Despite the high organic matter load, the treatment system dramatically reduced the average BOD from 471 mg l-1 up to an average of 88 mg l-1. The results indicated that the treatment system might be a very successful treatment application for rehabilitation of the creek ecosystem and thus the improvement of the water quality