2D/3D S-scheme heterojunction of carbon nitride/iodine-deficient bismuth oxyiodide for photocatalytic hydrogen production and bisphenol A degradation.

A novel 2D/3D S-scheme carbon nitride/iodine-deficient bismuth oxyiodide (g-C3N4/BiO1.2I0.6) heterojunction was constructed for the first time by calcining a mixture of g-C3N4 nanosheets and flower-like BiOI. Irradiated by visible light, this g-C3N4/BiO1.2I0.6 heterojunction exhibited excellent photocatalytic hydrogen production and BPA degradation activity with high cycle stability. In particular, the photocatalytic activity of 0.2-C3N4/BiO1.2I0.6 could reach 1402.7 µmol g-1 h-1 (hydrogen production rate) and 0.01155 min-1 (apparent rate of bisphenol A degradation), which were 3.5 and 3.2 times that of g-C3N4 respectively. The remarkable photocatalytic performance was due to the efficient charge separation of g-C3N4/BiO1.2I0.6 and the formation of S-scheme heterojunction, which maintained strong photocatalytic reduction and oxidation potentials. Noticeably, the charge density difference and band offsets of the g-C3N4/BiO1.2I0.6 were calculated. The results revealed that a built-in electric field (IEF) was created. The values of the valence band offset (ΔEVBO) and the conduction band offset (ΔECBO) were -0.84 and -1.27 eV, respectively, which further demonstrated the formation of S-scheme photocatalytic charge transfer mechanism.

Evaluation of urban inland waterway traffic noise using a modified Nord 2000 prediction model.

This study developed a prediction model for estimating urban inland waterway traffic noise emission level. The model based on the Scandinavian Nord 2000 method, which was modified by adding two categories of traffic flow, comprising light and heavy vessels, as well as vessel average speed to the calculating equations. Meanwhile, the influences of the water surface and embankment were also considered in the established model. Model verification was conducted using the data surveyed at the 30 sampling points of Danjinlicaohe Channel in Jiangsu Province of China. A high correlation was found between the predicted and measured noise values LAeq (Pearson correlation coefficient = 0.949, p < 0.01). And the mean difference between the predicted and measured noise values was 0.16 ± 1.28 dBA. The results showed that the proposed model had higher accuracy than the unmodified Nord 2000 method and can be applied for predicting vessel noise exposure level on inland waterway of China.

Development of a traffic noise prediction model on inland waterway of China using the FHWA.

Based on the local environmental standards, vessels types and traffic conditions, an inland waterway traffic noise prediction model was developed for use in China. This model was modified from the US FHWA model by adding the ground absorption and water surface attenuation correction terms to the governing equations. The parameters that were input into the equations, including traffic flow, vessel speed, distance from the center of the inland waterway to the receiver, position and height of the barriers and buildings, location of the receiver, type of ground, percentage of soft ground cover within the segment, and water surface conditions were re-defined. The model was validated by comparing the measured noise levels obtained at 33 sampling sites from Shugang Channel, Yanhe Channel and Danjinlicaohe Channel in China with the predicted values. The deviation between the predicted and measured noise levels within the range of ±1.5dB(A) was 81.8%. The mean difference between the predicted and measured noise levels was 0.15±1.75dB(A). However, the noise levels predicted developed model are generally higher than the measured levels. Overall, the comparison has proved that the developed method is of a high precision, and that it can be applied to estimate the traffic noise exposure level on inland waterway in China.

[Offshore ecosystem health status assessment: a review].

With the promotion of the concept of sustainable development, the issues of aquatic ecosystem health attract substantial attention, and considerable work has been carried out on the health assessment of waters, e. g. , rivers and lakes. However, the health assessment of offshore ecosystem is still at its exploratory stage. Based on the investigations on the related references at home and abroad, this paper analyzed the concepts of offshore ecosystem health assessment, summarized the main methods for the assessment, the principles for screening related indicators, and the research philosophy, and systematically listed the quantitative indices for the assessment. Aiming at the main existing issues in the researches of offshore ecosystem health, the future research directions about the offshore ecosystem health were suggested. It was considered that the concept and connotation analyses, the screening of assessment indicators, the choice of assessment scale, and the integration of assessment methods should be further strengthened to improve the assessment of offshore ecosystem health.