Effects of pH value and coagulant dosage on contact filtration of humic substances

Humic substances (especially fulvic acid (FA)) are the major components of natural organic matter (NOM) that widely exist in drinking water source. Due to their potential effects on public health,the removal of FA was one of the main concerns during the water treatment. Therefore,the contact filtration of FA by using aluminum sulfate as coagulant on the basis of jar tests was carried out. The effects of pH and coagulant dosage on the FA removal and the development of head loss were investigated. The results show that the range of pH value during the FA contact filtration can be effectively influenced by the dosage of aluminum sulfate,and the high aluminum sulfate dosage is an important factor that can result in early filter breakthrough. The FA filtration by deep-bed filtration or by membrane filtration is sometimes disparate under the same coagulation conditions. The choice of aluminum sulfate dosage by the method of membrane filtration,i.e. the "true color measurement",may result in inappropriate filter run,whereas it can be determined with simple jar tests by observing the formation of micro flocs. Considering the effects of pH on aluminum sulfate dosage and FA removal,the optimal pH range of 5.5?6.0 is suggested.

Prediction of load-displacement performance of grouted anchors in weathered granites using FastICA-MARS as a novel model

With the rising needs of better prediction of the load-displacement performance of grouted anchors in an era of developing large-scale underground infrastructures,the existing methods in literature lack an accurate analytical model for the real-life projects or rigorous understanding of the parameters such as grouting pressures.This paper proposes Fast ICA-MARS as a novel data-driven approach for the prediction of the load-displacement performance of uplift-resisting grouted anchors.The hybrid and data-driven Fast ICA-MARS approach integrates the multivariate adaptive regression splines(MARS)technique with the Fast ICA algorithm which is for Independent Component Analysis(ICA).A database of 4315 observations for 479 different anchors from 7 different projects is established.The database is then used to train,validate and compare the Fast ICA-MARS approach with the classical MARS approach.The developed Fast ICA-MARS model can provide more accurate predictions than MARS.Moreover,the developed Fast ICA-MARS model is easy to interpret since the evaluation of the parameter importance of the independent components can be conducted along with the considerations of the correlations with the original variables.It is noteworthy to point out that the grouting pressures play a central role in the proposed model,which is considered of paramount importance in engineering practices but has not been properly taken into account in any prior analytical or empirical predictive models for the load-displacement relationships.

Photovoltaics and Energy Storage Integrated Flexible Direct Current Distribution Systems of Buildings:Definition,Technology Review,and Application

For a future carbon-neutral society,it is a great challenge to coordinate between the demand and supply sides of a power grid with high penetration of renewable energy sources.In this paper,a general power distribution system of buildings,namely,PEDF(photovoltaics,energy storage,direct current,flexibility),is proposed to provide an effective solution from the demand side.A PEDF system integrates distributed photovoltaics,energy storages(including traditional and virtual energy storage),and a direct current distribution system into a building to provide flexible services for the external power grid.System topology and control strategies at the grid,building,and device levels are introduced and analyzed.We select representative work about key technologies of the PEDF system in recent years,analyze research focuses,and summarize their major challenges&future opportunities.Then,we introduce three real application cases of the PEDF system.On-site measurement results demonstrate its feasibility and advantages.With the rapid growth of renewable power production and electric vehicles,the PEDF system is a potential and promising approach for largescale integration of renewable energy in a carbon-neutral future.

Structural Progressive Mode of Urban Renewal and Public Participation in Shenzhen International Low Carbon City

By means of a structural progressive mode of urban renewal, which operates through small and medium-scale projects on the basis of public participation, the Shenzhen International Low Carbon City has provided propagable and replicable experience for urban planning and construction in urban marginal areas. This article fi rstly introduces the improvement measures for willingness and capabilities of public participation in the process of structural progressive renewal in the Shenzhen International Low Carbon City, and expounds the construction methods of participation approach, feedback mechanism, and interest balance, followed by an introduction of the rolling development strategy, micro municipal construction strategy and spatial-industrial-ecological integrated development strategy and practice experience, hoping to serve as a reference for the planning and construction of other cities in China.

Innovation practice in engineering management of the Shenzhen International Low-Carbon City

1 Introduction Shenzhen is a pioneer city in China's reform and development. The city has entered a post-industrialization stage and created the "Shenzhen Miracle" in the development of cities around the world after nearly 40 years of rapid development. In 2010, Shenzhen became one of the first low-carbon pilot cities in China. Since then, the city has taken the lead in explorations in many aspects, including developing low-carbon industries, building low-carbon cities, and advocating low-carbon life. Furthermore, the city has developed a duplicable and promotable sustainable development model for super-large cities.

The Exploration and Practice of the Development of Green Eco-Urban Areas in Guangzhou International Financial City

Active exploration has been carried out to determine a pattern for developing green eco-urban areas in the Starting Area of Guangzhou International Financial City with an emphasis on the core role of comprehensive green arrangement.By comparing and analyzing existing research,development of green technologies at home and abroad,and indicator systems of green urban areas of similar sizes,the builders developed a green ecological indicator system.They proposed a new concept called"district-level indicator" in order to emphasize the importance of classifying indicators according to different project situations.By verifying the indicators for all land parcels and assessing future costs and efficiency,experience accumulated in this project can be beneficial for future green eco-urban area development projects.

Shenzhen International Low Carbon City in Development: Practice of Low Carbon Planning Technology Strategy Based on Dynamic Demands

Targeted at the dynamic demands in the rapid urban construction, the planning technology strategy of the Shenzhen International Low Carbon City studies the fl exible index model based on carbon emission evaluation, and adopts rolling development and micro-circulation construction mode to achieve quick returns with small investment. Meanwhile, it also evaluates the application of low carbon technology and gives feedback in time, so as to constantly optimize and complete the low carbon city planning. In detail, it involves industrial planning, ecological restoration, transport planning, energy resource planning, architectural design, etc., for which appropriate approaches are selected according to the principle of rolling development of unit cells and based on different requirements of different stages. The quick-response and fl exible technology system can help the low carbon city to choose an appropriate technology strategy in line with its own characteristics in the start-up stage and rapid development, thus realizing the sustainable leap-forward development and providing reference for other similar regions.