A Study on the Standard Criteria of Irrigation Water Using Mass Balance Mehthod and Heavy Metal Toxicity Assessment

• Main Authors: Xing-Yi Liao, 廖行一
• Other Authors: Chia-Ming Chang
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/83360035593461251463

碩士 === 國立中興大學 === 土壤環境科學系所 === 97 === Due to the annual precipitation difference in Taiwan, agriculture development relies on irrigation, and water quality has tremendous influence. In the past, we mainly took irrigation water quality standards of United States as reference to set up our own. However, the applicability of those standards we completely imitate is not in accordance with any theory. In this study, Mass Balance and toxicity assessment are mainly used. The standard criteria, which conform to Taiwan’s, are established and theoretical based. The concept of Mass Balance is that the input of an element is equivalent to the output of it. Biological factor is mainly direct to the food corporations of rice; climate factor is mainly direct to the effective rainfall and dilution factor. In soil factor, elements have been fixed, leached and adsorbed with different clay. The above three were combined to estimate the standard criteria of irrigation water, and then we can establish one theoretical based criteria. Nitrogen: 6.60-125.12、Phosphorus :6.33-148.07、Potassium 1.91-10.18、Zinc 0.00-7.35、Lead 0.00-0.25、Copper 0.01-0.37、Arsenic 0.00-2.30、Cadmium 0.00-0.24、Nickel 0.00-0.27、Selenium 0.00-0.03、Manganese 0.03-1.67、Iron 0.00-21.35 mg/L. To supplement the deficiency of toxicity, six heavy metal parameters were used to estimate it. Among them, Hydrolysis, Hydration, and Ionization Energy were more influential than others. They could affect absorption of heavy metal, ion-exchange properties, biological toxicity, precipitation, and bonding capacity; moreover, the metal formation would be changed to different types. Today’s renewable water sources mostly come from the sanitation waste. If we want to use it for agricultural irrigation, we have to consider the process of disposing pathogens, risk analysis of virus, heavy metal, and other toxic substances. On the other hand, the environment and the hidden risks caused by human health must be considered. We should reject recycling polluted industrial wastewater in order to avoid secondary pollution and impacts on human health. In future development, this method will be able to set the standard criteria for irrigation water quality and suggested indicators. This will also ensure the balance of the environment. Furthermore, the regional irrigation water quality standards will be set up as a feasible scheme.