科研之友
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摘要
One of the main costly problems at wastewater treatment plants is the treatment of sludge, which is responsible for about 50% of the total operating cost of the whole treatment system. Chemical conditioning of sludge before dewatering is often necessary to increase the process efficiency of dewatering devices. Moringa oleifera seeds were evaluated as an alternative natural conditioning material during dewatering; as a single conditioner and as a base conditioner in dual polyelectrolytes conditioning (using Zetag 8140) for sewage sludge dewatering. The sewage sludge used in the experiments was collected from a sludge holding tank of the treatment plant located in Taman Shamelin Perkasa, Kuala Lumpur, while the M. oleifera seeds were collected from Serdang, Selangor, and stored in a room temperature for not more than 3 d, and then the quality seeds were identified and used. The preparation of the stock solution will start with placing the seeds in the oven for 24 h at 50 degrees C. After drying, the seeds were shelled and blended before use. The stock solution was prepared by using 50 g of M. oleifera powder with 1 L of distilled water to get a stock solution of 5,000 mg/L. Capillary suction time (CST), specific resistance to filtration, zeta potential, settled sludge volume, and sludge volume index (SVI) were used to evaluate the performance as a single conditioner and dual or co-conditioner in sludge dewatering. The lowest CST achieved using M. oleifera as a single conditioner was 7.1 s corresponding to a 5,000 mg/L dosage compared to 5.5 s achieved by using Zetag 8140 alone with a dosage of 13 mg/L. In dual polyelectrolytes conditioning, the minimum CST achieved was 4.6 s with a dosage of 2,000 mg/L M. oleifera and 9 mg/L of Zetag 8140. It can be concluded that at low dosages, dual polyelectrolytes show better conditioning compared with the use of M. oleifera as a single conditioner.
- 出版日期2015
