The assessment of rill irrigation and perforated pipes for Lowland paddy rice under the system of rice intensification (SRI)

Paddy and Water Environment - Irrigated paddy rice needs new strategies and tools to improve water use efficiency and productivity by applying just enough to sustain production with huge savings on...     

Ecological Risk, Mass Loading, and Occurrence of Nonylphenol (NP), NP Mono-, and Diethoxylate in Kaoping River and its Tributaries, Taiwan

Biochemically, nonylphenol ethoxylates (NPnEOs) and its breakdown products nonylphenol (NP), NP monoethoxylate (NP₁EO), and NP diethoxylate (NP₂EO) are considered endocrine disrupting compounds. These NPnEOs have been detected in aquatic environments and are of concern. NP, NP₁EO, and NP₂EO were detected in water samples collected from the main watercourse and polluted tributaries of Kaoping River, Taiwan. Concentrations were below the detection limit (<LOD) to 310 μg/l for NP, from <LOD to 27.2 μg/l for NP₁EO, and from <LOD to 27.5 μg/l for NP₂EO. It was found that concentrations of the three compounds in a low flow period were significantly greater than in the high flow period due to the low dilution effect. The risk to aquatic organisms by NP, NP₁EO, and NP₂EO was expressed as hazard quotient and hazard index and simulated with the Monte Carlo method. Results from this study suggested an inadequately treated domestic wastewater caused high concentrations of NP, NP₁EO, and NP₂EO and a high risk to aquatic organisms.