The build-up of phosphorus (P) in soil is a major factor limiting the operating life of a wastewater land treatment system. In this study, effects of long-term wastewater application on changes in chemical properties, P profiles, and P adsorption capacity were evaluated in soils of the Muskegon wastewater land treatment plant that has been treating wastewater for > 30 years. Results indicate that the major soil properties have been changed. In the 15 cm topsoil, the pH increased from ∼ 5-6 in 1973 to ∼ 7.4-7.8 in 2003; the soil's total organic carbon (TOC) increased by 10-71 %; and the level of exchangeable Ca in 2003 is 8-9 times higher than that in 1973. The amount of Ca/Mg absorbed in the soil affects the P adsorption capability of the soil; Ca-and Mg-bound P accounts for > 70 % of the total P adsorbed in the soil. The net P accumulated in the Rubicon soil increased from ∼ 700 in 1993 to ∼ 1345 kg/ha soil in 2001, but the plant available P varied between ∼ 100-500 kg/ha soil during the same period, indicating a large amount of the applied P has become the fixed P that is unavailable to plants. P sorption in the soil consists of a fast adsorption and a slow transformation process. The soil's maximum P sorption capacity (P max ) (based on 1-day isotherm tests) has been increased by ∼ 2-4 times since 1973; the actual P max of the Muskegon soils could be much higher than the 1-day P max . Therefore, the life expectancy of the Muskegon system has been extended significantly with the application of wastewater.
The occurrence and behavior of carbamazepine (CBZ) was investigated in aquatic environment of Yangtze River Delta, East China. The water samples were enriched by solid-phase extraction and analyzed by high-performance liquid chromatography with diode array detector. The validation of the analytical method included linearity (0.1-1 mg/L), recovery studies, and determination of limits of quantification. Limits of quantification of CBZ in various aquatic samples were in the range of 0.1-0.2 μg/L. CBZ was detected in the Tongji University Intramural River, the Huangpu River, and the Suzhou River with the highest concentration of 1,090 ng/L, but not detected in the Nanhengyin River and the Caojia River. In sewage water samples, CBZ was not detected in one of the sewage treatment plants (STPs) but was detected in the raw influents and effluents at the other three selected STPs in Shanghai, with the concentrations ranging from 230 to 1,110 ng/L. CBZ was not completely eliminated after secondary treatment (with the active sludge process).
International audienceTo improve signal-to-noise ratios (SNRs) in open air mass spectrometry, a laser-assisted, direct-analysis-in-real-time (DART) mass spectrometer (LA-DART-MS) was developed by integrating a continuous wave (CW) infrared (IR) laser into an open air DART-MS. The CW IR laser (wavelength of 1070 nm) was used to assist the desorption of analytes and promote the reactivity of protonated water from the DART ion source. Using the LA-DART-MS, SNRs of Rhodamine 6G (R6G), urea, and testosterone were enhanced by factors of 31, 11, and 4, respectively, compared with the conventional DART-MS. The sensitivity enhancement was ascribed to the increased analyte concentration in air and activated protonated water induced by the IR laser irradiation
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