Design of Water Network with Multiple Contaminants and Zero Discharge

The paper presents a procedure to design water network. First of all, water reuse system, water regeneration reuse system (including regeneration recycle) and wastewater treatment system are designed separately. But the interaction between different parts demands that each part is designed iteratively to optimize the whole water network. Therefore, on the basis of the separated design a water netvrork superstructure including reuse, regeneration and wastewater treatment is established from the system engineering point of view. And a multi-objective adaptive simulated annealing genetic algorithm is adopted to simultaneously integrate the overall water netvrork to balance the economic and environmental effects. The algorithm overcomes the defect of local optimum of simulated annealing (SA), avoids the pre-maturation of genetic algorithm (GA) and finds a set of solutions (pareto front) in acceptable computer time. Prom the pareto front, a point with minimum fresh water consumption will be extended to zero discharge as our ultimate goal.

Academic Study on the Technology Based on Sludge Concentration Subarea

Sludge concentration subarea(A area and B area) is realized by mesh filter unit,solving the higher sludge concentration process problem of MBR system under zero excess sludge discharge conditions.Mass balance of the system is processed,and variety disciplinarians of VSS of A area and B area are analyzed.The results show that XA decreases while HRTA increases.XB decreases while R increases,and ascends as VSS(XA,B) of mesh effluent increases.When XB is a fixed value,XA,B increases as R does and XA decreases slowly while R increases,which theoretically proves the feasibility of the technique.

Architecture Water-saving Design and Building Technique of Sponge Yard

The reclaimed water that we can use in daily life accounts for as much as 35 %,but we do not give it enough concern.The authors focus on the design methods and approaches of green buildings,which refer to water saving and environmental protection.In this paper,the authors illustrate the generating channels of reclaimed water in architecture design:rainwater collection integration design,sewage zero discharge of reclaimed water reused by biological technology,and sponge yard,thereby protecting environment.

Zero increase in peak discharge for sustainable development

For urban land development, some or all natural land uses （primarily pervious） are converted into impervious areas which lead to increases of runoff volume and peak discharge. Most of the developed countries require a zero increase in peak discharge for any land development, and the policy has been implemented for several decades. The policy of zero increase in peak discharge can be considered as historical and early stage for the low impact development （LID） and sustainable development, which is to maintain natural hydrological conditions by storing a part or all of additional runoff due to the development on site. The paper will discuss the policy, the policy implementation for individual projects and their impact on regional hydrology. The design rainfalls for sizing LID facilities that are determined in 206 weather stations in USA are smaller than design rainfalls for sizing detention basins.The zero-increase policy links to financial responsibility and sustainability for construction of urban stormwater infrastructures and for reducing urban flooding. The policy was compared with current practices of urban development in China to shine the light for solving urban stormwater problems. The connections and differences among LID practices, the zero-increase policy, and the flood control infrastructure were discussed. We promote and advocate the zero-increase policy on peak discharge for comprehensive stormwater management in China in addition to LID.

Preparation of microparticles and nanoparticles using membrane-assisted dispersion,micromixing,and evaporation processes

Synthetic microporous membranes are increasingly used for energy-efficient and controlled production of micro-and nanoparticles and micro-and nanoemulsions with tuneable morphology and physico-chemical properties through various micromixing,emulsification,and evaporation processes.In emul-sification processes,the membrane pores are used for dispersed phase injection and size-controlled generation of droplets and droplet-templated particles.In micromixing processes,membrane is utilised as a micromixer for mixing two miscible liquids,usually solvent and antisolvent-rich solutions,which leads to the creation of supersaturation and subsequent nanoprecipitation or crystallisation.In mem-brane evaporation processes,membrane is used to prevent phase dispersion while allowing efficient molecular diffusion of solvent and/or antisolvent vapour through gas-filled pores.Membrane dispersion processes can be operated continuously by decoupling shear stress on the membrane surface from cross flow using tube insets,flow pulsations,swirling flow,membrane oscillations or membrane rotations.Droplet generation and solidification can be performed continuously in a single pass by connecting membrane module with a downstream reactor.Membrane dispersion processes can be used for pro-duction of nanoparticles such as nanovesicles(liposomes,micelles,ethosomes,and niosomes),nanogels,polymeric,lipid and metallic nanoparticles,and nanocrystals.The main advantages of membrane-assisted particle generation are in low energy consumption,controlled geometry and hydrodynamic conditions at the microscale level,flexible throughput due to modular and scalable design of membrane devices,and a wide choice of available microporous membranes with various wall porosities,wetta-bilities,pore sizes,and pore morphologies to suit different applications.

Technical measures to achieve a cleaner production mode for recycled paper mills

China’s paper production reached 79.8×10^(6) t in 2008 and ranked number one in the world.Because of its high consumption of water,energy and materials and its serious pollution,the present processes are not likely to be sustainable.An alternative,the closed Water Loop-Papermaking Integration(WLPI)method,is put forward in this paper.The WLPI method can be realized in a recycled paper mill by adding technologies and using recycled water.Many industrial case studies have shown that a large quantity of water,energy and materials can be saved,and the quantity of waste sludge and wastewater discharge was minimized by using the WLPI method.The design of the water reuse system,control of calcium hardness,water recycling and minimal waste sludge are discussed.Anaerobic technology plays an important role in the WLPI method to lower cost,energy use and waste.In the brown paper and coated white board production,zeroeffluent discharge can be realized.Fresh water consumption is only 1-2m^(3)·t^(-1).For the paper mills with deinking and bleaching processes,about 10 m^(3)·t^(-1) of fresh water and a similar amount of effluent discharge are needed.Power saving using anaerobic technology is 70%when recycled water is used in comparison with the conventional activated sludge process.Waste sludge can be decreased to about 5%of the initial process due to reuse of the waste sludge and the lower bio-sludge production of the anaerobic process.