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Inclusion complexes were formed by including the pesticide beta-cypermethrin (BC) in sulfonated hydroxyethylβ-cyclodextrin (SHECD) and sulfobutyl ether β-cyclodextrin (SBECD), and these complexes were then intercalated into the galleries of layered double hydroxides (LDHs) to synthesize BC/SHECD−LDH and BC/SBECD−LDH hybrids. The hybrids were characterized by powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, thermogravimetry/ differential thermal analysis (TGA/DTA), and scanning electron microscopy (SEM). The results showed that BC/SHECD− LDH and BC/SBECD−LDH had basal spacings of 1.64 and 2.12 nm, respectively, which were analyzed on the basis of the structural properties of cyclodextrin (CD). The combustion temperature of interlayer SHECD was increased by 140 °C through intercalation. Furthermore, the release behaviors of BC from BC/SHECD−LDH and BC/SBECD−LDH composites were investigated. The release of BC from the hybrids was faster at pH 6.8 than at pH 5.0, and the released amounts were higher at the former pH, in close correlation with the structural type of CD and the release media. The BC release kinetic processes were wellfitted with pseudo-second-order and parabolic diffusion models. BC/SHECD−LDH could potentially be applied for pesticide formulation.

Reservoirs play an important role in the urban water supply, yet reservoirs receive an influx of large amounts of pollutants from the upper watershed during flood seasons, causing a decline in water quality and threatening the water supply. Identifying major pollution sources and assessing water quality risks are important for the environmental protection of reservoirs. In this paper, the principal component/factor analysis-multiple linear regression (PCA/FA-MLR) model and Bayesian networks (BNs) are integrated to identify water pollution sources and assess the water quality risk in different precipitation conditions, which provides an effective framework for water quality management during flood seasons. The deterioration of the water quality of rivers in the flood season is found to be the main reason for the deterioration in the reservoir water quality. The nonpoint source pollution is the major pollution source of the reservoir, which contributes 53.20%, 48.41%, 72.69%, and 68.06% of the total nitrogen (TN), phosphorus (TP), fecal coliforms (F.coli), and turbidity (TUB), respectively. The risk of the water quality parameters exceeding the surface water standard under different hydrological conditions is assessed. The results show that the probability of the exceedance rate of TN, TP, and F.coli increases from 91.13%, 3.40%, and 3.34%, to 95.75%, 25.77%, and 12.76% as the monthly rainfall increases from ≤68.25 mm to >190.18 mm. The risk to the water quality of the Biliuhe River reservoir is found to increase with the rising rainfall intensity, the water quality risk at the inlet during the flood season is found to be much greater than that at the dam site, and the increasing trend of TP and turbidity is greater than that of TN and F.coli. The risk of five-day biochemical oxygen demand (BOD5) does not increase with increasing precipitation, indicating that it is less affected by nonpoint source pollution. The results of this study can provide a research basis for water environment management during flood seasons.

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