[Extensive Green Roof Substrate Composition Based on Sludge Recycling].

The experiment was carried out to study the reasonable composition of stable anaerobic sludge in the extensive green roof growth substrate by a total of 650 mm artificial rainfall event. Combined with the N, P leaching problem of the sludge resources utilization, the quality of the effluent and the change of the nutrient content of the substrate in the process of application were investigated. The results showed that the anaerobic sludge could significantly increase the plant biomass and the average weight gain was 808%. Stable anaerobic sludge caused a large amount of leaching of TP and water treatment residual could effectively control TP leaching and did not affect the absorption of P to the plant. During the experiment, the TP of the effluent was reduced by 68.66%.After stabilization, the effluent TP reached the surface water Ⅴ standard. The main form of leached TN was NO3--N and the leaching of NO3--N could be reduced by rice husk charcoal. In the experiment, the NO3- -N leaching mass was reduced by 28.86% totally. Increasing the amount of rice husk charcoal helped to control NO3--N leaching. SS and COD could be quickly decreased and stabilized. The COD of effluent after stabilization was about 30 mg·L-1, which was better than the standard of surface water Ⅴ. Under the condition of actual precipitation with medium and small rainfall, the anaerobic sludge nutrient retention time should be more than 1 year, which meets the growing needs of plants for a long time.

[Removal of Polycyclic Aromatic Hydrocarbons by Extensive Green Roofs].

In this study,four pilot-scale extensive green roof facilities with different substrate compositions were developed. In 8 rainfall events, concentrations of 16 kinds of polycyclic aromatic hydrocarbons (PAHs) in effluent of these facilities were investigated and compared with effluents of asphalt roofing, the blank control roof and rain water. Average PAHs concentrations in the effluent of these four facilities, asphalt roofing and blank control facilities were 145, 166, 151, 160, 900, 270 ng·L-1, respectively. The PAHs mass concentrations discharged by four simulation facilities were significantly lower than asphalt roofing and blank control roof. From the perspective of the mass loading control, all four simulation facilities could effectively control roof runoff PAHs load with an average load reduction rate of 71.76% compared with the blank control roof. Interception and adsorption by green roof substrates was the main removal way for PAHs. Facilities' PAHs removal efficiency could be improved by increasing the substrate thickness with the same substrate composition. Transforming traditional asphalt roofing into extensive green roof was an effective way to control PAHs emissions from roof runoff.

[Performance of Grass Swales for Controlling Pollution of Roadway Runoff in Field Experiments].

Two different styles of grass swales were built in new Binhu region of Hefei city to monitor the flux and quality of the influent and effluent water under actual precipitation conditions, in order to evaluate the performance of water quality purification and pollution load control for roadway runoff. The results showed that both of the grass swales could effectively remove the pollutants such as TSS, COD, Pb, Cu, Cd, Zn in roadway runoff; the median EMC removal efficiencies of TSS and COD were 67.1%, 46.7% respectively,for facility I, and the median EMC removal efficiencies of TSS and COD were 78.6%, 58.6% respectively, for facility II; the concentrations of Pb, Cu, Zn in the effluent of facility II could meet the requirements of the surface water quality class V; release of nitrogen and phosphorus occurred in both facilities I and I[ in several rainfall events, mainly in heavy storms; the removal efficiencies of TP in the two grass swales were improved with the increase of influent concentration; the mean removal efficiencies of TP in facilities I and II were 14.7% and 45.4%, respectively; the load control performance of facility II for pollutants such as TSS, COD, TP, TN, NH4+ -N and NO3- -N was better than that of facility I; in the district with poor soil permeability and low ground slope, application of dry swale could achieve better performance in water quality control and pollution load reduction of roadway runoff.

[Effects of mesenchymal stem cells transplantation on cranial suture distraction osteogenesis in growing goats].

OBJECTIVE: To observe the effects of mesenchymal stem cells (MSCs)on cranial suture under mechanical strain in growing goats. METHODS: 10 growing goats were used in this study. A customized distractor was used for distraction of the coronal suture at a rate of 0.4 mm/day for 8 days. The experimental group(5 goats) was injected with autologous MSCs into the distracted region, whereas the control group (5 goats) with injection of physiological saline. All animals were killed at 4 weeks after the end of distraction. Scanning electron microscopy and histological analysis were taken to observe the samples. RESULTS: 4 weeks after the end of distraction, the cranial sutures in all animals were separated successfully. The new bone formation at the edge of suture in the experimental group was superior to that in the control group. CONCLUSION: Autologous MSCs transplantation may promote the cranial suture distraction osteogenesis in the growing goats.