While point source pollutions have gradually been controlled in recent years, the non-point source pollution problem has become increasingly prominent. The receiving waters are frequently polluted by the initial stormwater from the separate stormwater system and the wastewater from sewage pipes through stormwater pipes. Consequently, calculating the intercepted runoff depth has become a problem that must be resolved immediately for initial stormwater pollution management. The accurate calculation of intercepted runoff depth provides a solid foundation for selecting the appropriate size of intercepting facilities in drainage and interception projects. This study establishes a separate stormwater system for the Yishan Building watershed of Fuzhou City using the InfoWorks Integrated Catchment Management (InfoWorks ICM), which can predict the stormwater flow velocity and the flow of discharge outlet after each rainfall. The intercepted runoff depth is calculated from the stormwater quality and environmental capacity of the receiving waters. The average intercepted runoff depth from six rainfall events is calculated as 4.1 mm based on stormwater quality. The average intercepted runoff depth from six rainfall events is calculated as 4.4 mm based on the environmental capacity of the receiving waters. The intercepted runoff depth differs when calculated from various aspects. The selection of the intercepted runoff depth depends on the goal of water quality control, the self-purification capacity of the water bodies, and other factors of the region.

•The energy conservation and the GHG reduction benefits on aggregate reuse in overpass projects are determined.•Many important first-hand data on some life cycle stages are gathered.•To reduce the energy consumption and GHG emissions from the overpass projects, the cement consumption must be reduced.Currently urban overpasses (new-construction, reconstruction and extension) are being constructed on a large scale in China. While the construction projects are beneficial to the economic and social development, they have also caused serious ecological and environmental problems. On one hand, the final disposal of construction wastes requires a large amount of land, and the extraction of virgin aggregate destroys the local ecological environment. On the other hand, the energy consumption and the greenhouse gas (GHG) emissions during the entire life cycle are massive. To reduce the ecological and environmental impacts and to improve the resource use efficiency during the overpass construction, it is necessary to change the traditional linear resource use mode (aggregate–buildings–garbage) into a circular mode (aggregate–buildings–reused/regenerated aggregate–buildings). Using the life cycle inventory (LCI) method, the energy consumption and the GHG emissions are investigated for two different kinds of reconstruction and extension projects for overpasses in Shanghai City, using virgin and regenerated aggregates, respectively. Through that, the actual energy conservation and the GHG reduction benefits from using the regenerated aggregate are determined. Important first-hand data on the extraction of aggregate, the regeneration of aggregate, and the demolition of the discarded overpass, in a real situation, are gathered. The results show that, for the life cycle of aggregate, the energy consumption and the GHG emissions from reused aggregate can be reduced to 45.27% and 43.91%, respectively, compared to the virgin aggregate. For the life cycle of road concrete, the figures mentioned above would be 3.48% and 1.33%, respectively. In order to reduce the total energy consumption and GHG emissions from the reconstruction and extension projects of the overpasses, it is essential to find a way to reduce the amount of cement used, as well as the energy consumed and the GHG emitted during the cement production.

The reductive dehalogenation of brominated disinfection byproducts (DBPs) including bromoform and tribromoacetic acid (TBAA) by iron based bimetallic systems (Cu/Fe and Pd/Fe) was investigated. In Cu/Fe bimetallic system, only 8.1% of bromoform and 20.1% of TBAA were reduced within 20 min when the particle dosage was 5 g L−1, while 56.9% of bromoform and 62.7% of TBAA were removed in the same period when the dosage increased to 20 g L−1. A complete removal of bromoform and TBAA was achieved within 60 min of reaction in acidic conditions, while only 35.4% of bromoform and 10.8% of TBAA were removed after the whole experimental period (140 min) in alkaline conditions. Similar results were observed in a Pd/Fe bimetallic system. Bimetallic particles achieved high performance probably because galvanic cells were created between Fe (serving as an anode) and plating elements (serving as a cathode). This structure enhanced the reducibility of iron for reductive dehalogenation by facilitating iron corrosion as well as reducing the activation barrier of H2. The Pd/Fe system showed a better performance than Cu/Fe, which was attributed to a higher potential gradient (1.4 V) as compared to Cu/Fe couples (0.8 V). Furthermore, toxic assessment indicated that the toxicity of water samples had a dramatic decline after dehalogenation by bimetallic particles.

Nitrogen causes the frequent occurrence of harmful algal blooms and possible microcystin production. The effects of ammonia and alanine (Ala) on the growth and microcystin production of Microcystis aeruginosa were investigated using an isotope tracer (15N). The results indicated that Ala was directly used by M. aeruginosa and contributed to biomass formation amounting to 2.1 × 107 cells mL−1 on day 48, compared with only 6.2 × 106 cells mL−1 from ammonia alone. Microcystin-LR production with Ala was less than that of ammonia, which peaked at 50.2 fg cell−1 on day 6. Liquid chromatographic analysis with tandem mass spectrometry of 15N–microcystin-LR suggested that 15N from ammonia was probably synthesized into the arginine residue. By contrast, 15N from Ala was assimilated into the Ala, leucine, the iso-linked (2R,3S)-3-methylaspartic acid, arginine, and certain unusual C20 amino acid residues. The results represent the forward steps in the determination of the nitrogen forms that fuel toxin production and blooms.

Effluent organic matter from biological wastewater treatment plants is composed of degradation products and soluble microbial products (SMP). Protein, polysaccharide, humic acid, and DNA were major biomolecules of SMP. Little is known about the effects of SMP as microbially derived precursors on disinfection byproduct formation and speciation in biologically treated wastewater. In addition, there has never been any attempt to directly chlorinate the major biomolecules of SMP.In this study, model compounds (bovine serum albumin, starch, DNA, and humic acid) and SMP collected from a sequencing batch reactor (SBR) were chlorinated to verify the trihalomethane and haloacetic acid species that were produced from them.The results showed that chloroform, dichlorobromomethane, dichloroacetic acid, and trichloroacetic acid were generated from the chlorination of SMP in the SBR, and there was a close relationship between the species predicted from the model chemical compounds and those obtained from the SMP.

This study investigated the effect of copper on chemical oxygen demand (COD) removal efficiency and on the properties (mainly settling and dewatering) and the composition of extracellular polymeric substances (EPS) when 20 mg/L Cu(II) was continuously dosed to a sequencing batch reactor (SBR) inoculated with activated sludge.The results showed that the continuous addition of 20 mg/L Cu(II) seriously inhibited the removal of sodium benzoate (provided as a model organic pollutant) by activated sludge in a SBR.After 40 days of acclimation, the removal efficiency presented a slight but unsteady recovery and the settling and dewatering properties improved, indicating that sludge bulking had been inhibited. Additionally, the proportion of loosely bound EPS in the total EPS increased with time and the relative composition of the total organics was polysaccharide > humic substances > protein > DNA.The effects of copper on the composition of EPS and the settling and dewatering properties of bulking activated sludge were also discussed for the first time in this paper.

Many advanced oxidation technologies have been developed to remove ammonia in wastewater. All these technologies have one common characteristic, that is, the removal processes involve OH radical (•OH). In this research work, H2O2 was selected as •OH precursor. The removal of ammonia under 253.7 nm irradiation from low-pressure mercury lamp in the presence of H2O2 was studied to investigate the ammonia removal efficiency by •OH. Results show that the •OH, generated by H2O2 photolysis, could oxidize NH3 to NO2− and further to NO3−. Removal efficiencies of ammonia were low and were affected by initial pH value and ammonia concentration. Laser flash photolysis technique with transient absorption spectra of nanosecond was used to investigate the oxidation pathway and kinetics of ammonia oxidation by •OH. Results illustrate that •OH could oxidize NH3 to form •NH2 with a second-order rate constant of (1.0 ± 0.1) × 108 M−1 s−1 (20 °C). •NH2, the main product of •OH with NH3, would further react with H2O2 to yield •NHOH. Since •NHOH could not stay stable in solution, it would rapidly convert to NH2O2− and consequently NO2− and NO3−. The rate constants for these elementary reactions were also given. The low removal efficiency of ammonia by •OH was mainly due to the slow reaction rate constant.