Evaluation of Water Quality Management Alternatives to Control Dissolved Oxygen and Un-ionized Ammonia for Ravi River in
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Evaluation of Water Quality Management Alternatives to Control Dissolved Oxygen and Un-ionized Ammonia for Ravi River in Pakistan Husnain Haider & Waris Ali Received: 28 February 2011 / Accepted: 12 December 2012 / Published online: 30 December 2012 # Springer Science+Business Media Dordrecht 2012
Abstract Different water quality management alternatives, including conventional wastewater treatment, transportation of wastewater, flow augmentation, low-cost treatment with reuse, and wetlands, are evaluated by using a verified dissolved oxygen (DO) model for the Ravi River. Biokinetic rate coefficients of the Ravi River for both the carbonaceous and nitrogenous oxygen-demanding wastes are adjusted, keeping in view the type and level of wastewater treatment. The conventional activated sludge process with nitrification comes out to be the most expansive alternative to meet the DO standard of 4 mg/L. Additional treatment cost is required to maintain un-ionized ammonia levels 90 %), keeping the required alkalinity and DO concentrations, about 6–7 days of hydraulic retention time (HRT) is required [17]. For such higher HRT, the land requirements are high [19]. Therefore, they are not considered as a potential alternative to treat large volumes of wastewater from the city of Lahore [2].
Ravi River MA7CD at Shahadra gauging station=9.2 m3/s River average temperature during winter low flow season=17 °C pH07–7.5 DOSATURATION =9.67 mg/L Actual DORIVER =8.0 mg/L (85 % saturation as per field observations) BOD5=7.0 mg/L CBODU=7.9 mg/L NBODU=5.5 mg/L QB Link Canal Average annual flow=395.6 m3/s (1995–2004 data) BOD5=6.0 mg/L CBODU=6.7 mg/L NBODU=4.57 mg/L
Evaluation of Water Quality Management Alternatives
3.2 A-2: Flow Augmentation The average monthly flow in the MR Link Canal ranges between 36 and 565 m3/s during the months of April to October (1995–2004) [11]. This means that MR Link Canal can carry up to 565 m3/s. The possibility of flow augmentation from MR Link Canal from Siphon through the Ravi River under low-flow conditions (i.e., MA7CD) to augment river flow to achieve the desired DO levels is also investigated in this research. 3.3 A-3: Wastewater Transportation Transportation of NE District, Main Outfall, Gulshan Ravi, Multan Road Outfalls, and Hudiara Drain flows through a collector channel to the QB Link Canal confluence point is another potential alternative for Ravi River WQM. In this way, benefit of dilution from QB Link Canal can be utilized to minimize the cost of wastewater treatment. Average annual flow in QB Link Canal is 395.6 m3/s, which is about nine times higher than the estimated future wastewater flow from the previously mentioned sources of wastewater. Deg Drain joins the UCC canal at about 20 km upstream and commonly utilizes the dilution from UCC. During the canal closure period, only Deg Drain’s flow enters into the Ravi River; therefore, wastewater treatment before the confluence of UCC is the only viable option for the Deg Drain wastewater in this alternative. 3.4 A-4: Low-Cost Treatment WSP ha
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