ACUTE TOXICITY EVALUATION OF TREATED RIVER WATER WITH AERATION METHODS (Case study: Cikakembang River)

• Main Author: PUTRI PRADITA NIM : 25315316, DEA
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/26428
• Institution: Institut Teknologi Bandung

Several industries in Citarum Hulu tributaries discharge their wastewater straight into the river. Cikakembang River becomes a location of wastewater discharges from textile industry around Majalaya area, causing water quality in Cikakembang River decreases. Thus, further water treatment to increases water quality is needed. Aeration is one of the method that use in water treatment. The process that occured in aeration involving contact between water and air in order to transfer the air into the water. The process reduced the pollution based on physicochemical parameters for water quality. This research aimed to compare acute toxicity of the river water prior to aeration and after aeration process. Acute toxicity test conducted by observing mortality of D.magna for 96 hours. LC50 is then converted into TUa value (Toxicity Unit Acute) value. Physicochemical parameter and microplastic concentration also measured in order to determine its relations with acute toxicity. The results of acute toxicity test show that prior to aeration, water sample that collected at noon has TUa value 0.467± 0.12, while water sample that collected at night has TUa value 1.36 ± 0.3. After the aeration using diffuser, mechanical aeration, and cascade aeration, water sample that collected at noon has TUa value 0.01 ± 0.002 (86%), 0.08 ± 0.04 (68%), and 0.30 ± 0.2 (42%), proving the water was not toxic. The result is different with the sample that collected at night, which has high acute toxicity. TUa value after diffuse aeration, mechanical aeration, and cascade aeration respectively are 0.13 ± 0.02 (90,4%), 0.44 ± 0.13 (67%), and 1.04 ± 0.13 (23%). The different results prove that aeration has different capacity in lowering water toxicity. Furthermore, the relation of physicochemical parameters and toxicity also determined. Toxicity results after cascade aeration have strong relation with parameters total phosphate, salinity, nitrite, and COD. Toxicity results after mechanical aeration have strong relation with TSS, salinity, COD, and total phosphate. Toxicity results after diffuse aeration have strong relation with nitrite. The existence of microplastic in the water did not affect mortality of Daphnia magna. Microplastic also did not found inside the body of Daphnia magna. <br /> <br />