| Summary: | 碩士 === 嘉南藥理科技大學 === 環境工程與科學系 === 100 === In recent years, high nitrate concentration in groundwater has gained global attention. There are a several technologies that are commonly utilized in the
removal of nitrate from raw water.
Raw water was obtained from a groundwater monitoring well from central region of waterworks in Taiwan. In the ED study, nitrate removal efficiency was examined, the water quality of the product effluent was analyzed and power cost analysis was determined. The results show that increasing the voltage applied causes an increase in the nitrate removal efficiency. Within the voltage range of 30 to 60V, about 52.50% to 63.34% of nitrate removal efficiency was obtained in shorter reaction time of 30s. Under an applied voltage of 60V, the removal rate was observed to decrease from 63.34%
to 44.17% as flow rate was increased from 2 L/min to 5 L/min.
The effect of alkalinity on nitrate removal is insignificant. Using a low voltage, groundwater was treated using ED for two treatment cycles. An increase in power consumption but with no apparent increase in the recovery of product water (64%) was observed. Electricity consumption was observed to be stable, where a voltage increase of 10 V corresponds to a 0.1 kWh consumption of electricity. The electricity utilized in one treatment cycle of EDR is an average of 3 kWh. A removal efficiency of 30.89% to 66.90% would utilize a voltage in the range of 10 to 60 V, when the nitrate concentration about
11.7mg/L to 17.1mg/L.
Using a voltage of 35 V, one ton of power is consumed of 3.05 degree that provides a 55% residual nitrate and 45% nitrate removal. Hydroponic cultivation method was utilized in the treatment of nitrate from wastewater, where nitrate was absorbed using hydroponic vegetables. The uptake of nitrate could also
serve as a fertilizer in the growth of hydroponic vegetables.
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