Study on water environment restoration and urban water system healthy circulation

Study on water environment restoration and urban water systemhealthy circulationZhang Jie'，Li Dong2(1. School of Municipal & Enionmental Engineering, Harbin Institute of Technology ,Harbin 150090 ,China;2. Key Laboratory of Biing for Water Quality Science and Water Environment RecoveryEngineering,Beijing University of Technology，Beijjing 100124，China)Abstract :Studied on the law and interaction of hydrological cycle and social water circulation on the earth,it is pointedout that the water environment, water resources and water cycle are the unity of water movement. The roots of contempo-rary crisis are also analyzed. The strategy of water environment recovery and social water healthy cycle is proposed andapplied in many eities ，which has achieved good results.Key words: water environment ; water system; healthy cycle1 Introduction2 Law of water cycleAfter the Industrial Revolution in the 18th century，2.1 Natural hydrological cycleespecially in the last half century , human beings take aDriven by solar energy, water continues the cyclelifestyle of excessive consumption and a large numberin ocean, sky and the mainland, which is called theof waste production, which threalens human survivalnatural hydrological cycle, as shown in Fig. 1. The to-and development. Nature has now overwhelmed. Ontal cycle is equal to the total precipitation, or the totalMay 22，2002， UNEP ( United Nations Envionmentevaporation on earth, 5.77 x10' km' per year. The to-Programme) pointed out that currently half of the riverstal runof of mainland is the difference of precipitationin the world were seriously polluted and the flow of wa-and evaporation in mainland, so is that of ocean. Pre-ter substantially reduced. The number of people livingcipitation is more than evaporation in mainland, whilein areas with severe water pressure, in both absoluteit is opposite in ocean. Surface and underground runoffand relative terms, increases virtually in all parts of theflows from mainland to ocean because of the differenceglobe. An estimated 55 % of the global population isin precipitation and evaporation of mainland andaffected, up from over 40 % in 2002.ocean; thus river, lake, and underground runoff comeChinese government has always attached impor-into being of water environment which nourishes thetance to prevention of water pollution by a series of ac-growth of all lives on earth, and also is the basis of antions such as “who pollutes who manages" ，“ threeirreplaceable natural resource of human society.simultaneous",“Huaihe zero action" and so on, butwith no effect. Half a century later, river pollution in-creases year by year. The situation is still that waterpollution is improved in the local, but the general trend:72 10km3of the national river pollution has not yet been.05文10 km'checked.In fact a comprehensive water crisis is imminent.4.58年 KmToday we should recognize clearly that people in har-、Surface and undougrcound runf0A7X1021mony with the natural water environment should not de-MainlandOceanstroy the natural hydrological cycle, but regulate thewater activities of human society to realize the healthyFig. 1 Natural circulation of watercirculation of social water. Only in this way human so-2.2 Social water cvcleciety can realize sustainable development.In the .中国煤化工human continu-YHCNMHGReceired 10 Norember 20114 Engineering Sciencesously use the surface and underground runoff to meetfication and supply system， wastewater collection,the need of life and production. The formation of thistreatment, discharge and recycling system, is shown inartificial water cycle is called social water cycle. UrbanFig.2. Water is the city' s blood and supply and drain-water supply and drainage system, irrigation system ,age system seems to be the arteries and veins, which isand water use system all belong to social water cycle.cycled in the city. It is an unified organic circulatoryUrban water system，including natural water puri-system, and neither can be neglected.Water distribution systemWater supply systemDrainage systemUndergroundIa----FrunoffWater abstractionand supply,"Sewage collectionand disposalUpstreamSurface water & runoffor occap/”Potential reuse of waterFig.2 Social circulation of water2.3 Interaction between social water cycle and3.2 Dualistic view of naturenature hydrological cycleChina ' s ancient plain materialist view of nature isSociety water cycle is an additional part of thethat people should be in harmony with nature, and hu-hydrological cycle, which is a special water cycleman and social development should be subordinated tomarked by the human activities. It is attached belowthe law of nature. The ancient Taoism founded by Laothe earth' s natural water cycle, and has a strongZi advocated “Heaven and people combined" . Today ,exchange with each other. Society and natural waterin the support of modern science and technology, hu-cycle form a large complex earth water cycle system.man beings think of themselves as the masters of na-ture; that is to say “everything becomes possible ”.3 Roots of water shortage，pollution andDualistic view of nature is the social and ideologicalcrisisroot of the water crisis.3.1 Modern population explosion3.3 Excessive grab, inefficient use and pollutionAfter the birth of human beings ，population hademissionbeen very rare among millions of years, as shown inUnder the guidance of the dualism view of nature,Fig. 3. The population reached 1 billion until 1850 ,people access excessively, use water roughly and drainand 80 years later, this number doubled and reachedpollution in order to seek the greatest economic bene-2 billion. After another 45 years, the number doubledfit, which leads to water shortage ，pollution and crisis.again, about 4 billion in 1975 and it reached 6 billionHuman beings carrying on water activities givein 1999. It is now growing at the rate of 55 million perise to huge energy and production efficiency; at theyear. Population explosion, which imposes tremendoussame time, this “double-edged sword” will bring dis-pressure on global environment and resources, is theaster increasingly to the fore.ultimate cause of the water crisis.Aral Sea，the world' s largest inland saltwaterlake, is the fate of the Amu Darya and Syr Darya. Inthe 1950s, due to the construction of reservoirs in theupper reaches of two rivers, digging canals and expan-reached 6 bllion in 1999ding the irrigated area, the inflow of two rivers into thesea decreased year by year. By 1974， the water ofAmu Darya into the sea had reduced 37. 5 %Syrdarya , almost having no runoff into the sea for manymu5s2032years, result中国煤化工d7 m, reducedwater area ofFion reduced from200 000 BCAD 19501492 1776 19924.8x10' quinMHCN M H Gtals in 1978.Fig.3 The process of global population explosionThe formation of irigation water system of EgyptVol. 10 No. 1 ,Feb.2012 15Aswan causes soil salinization area enlarging at arSpring in 1950s， the contradiction between the devel-alarming rate; schistosomiasis and malaria have beopment of human society and the natural environmentcome long-term disasters in Egypt; in eastern Mediter-was recognized. In 1972, World Environment Confer-ranean, also due to the lack of nutrients from the Nile ,ence in Stockholm published Declaration of United Na-plankton reduces by 1/3， resulting in huge loss ofions Conference on Human Enwironment and Club ofEgypt fishing.Rome published The Limits to Growth. W orld Commis-The destruction of human activities on water qualitysion on Environment and Development was establishedare common occurrences, such as a factory or a city pol-and published Our Common Future in 1982. In 1992 ,luting a river. Class V and less than class V water ac-Rio Declaration on Enwironment and Derelopment andcount for 25 % of China's 7 major river systems. Algae21st Century Agenda were summited by WSSD ( Worldblooms in Chaohu Lake, Dianchi Lake and Taihu Lake;Sunmit on Sustainable Development). The sustainablered tide occurred in coastal waters and area increases sig-development strategy was gradually established andnificantly year by year ; urban groundwater was pollutedimproved. .in general; drying, pollution, and water shortage are inIn 1960s, Boulding's Spacecrafit Concept of Eco-common. Social water cycle has given a strong impact onnomic created circular economy theory. Now, ecollogi-the natural hydrological cycle.cal laws guiding human economic activities areeffective ways for sustainable development.4 Establishment of social water healthyThe healthy cycle of water and material of humancyclesociety is the basis of circular economy with the 3RFacing the global water crisis caused by a lot ofprinciple: Reduce, Reuse, Recycle.sewage and abandoned waste discharged by people and6 Strategy of social water healthy cycle andexcessive use of pesticides and fertilizers, we proposedwater environment recoverya“social water healthy cycle" concept. On one hand,following the law of the hydrological cycle in theAs shown in Fig. 4，controlling the use of waterprocess of social cycle， control social cycle flow andand separating the pollution in origin are the coresource pollution, at the same time purify the used waconcepts.ter to reuse and recycle, and make the water cycle of1) Control the use of water and separate the pol-the upper reaches not to affect the functions of down-lution in origin. Advocate water conservation， waterstream and impair the law of the natural cycle so as toeconomical usage, and ecology water protection for riv-maintain or restore the healthy water environment of ur-er basin. Take emphasis on pollutants separating fromban and drainage and realize sustainable usage of wa-sources. Advocale habitat ecological sanitation system,ter. On the other hand, cycle of material is mainly theclean industry production, and recycle nutrient, indus-cycle of nutrients rich in food, such as N, P, K, andtrial raw materials and intermediate products.so on, which is a branch of natural cyele of plant nutri-2) Reuse and recycle the wastewater. Sewage is aents. The healthy cycle of social material means novaluable fresh water resource, and high-quality recy-harm to plant nutrients cycle, no nutrients loss ，and nocled water is one of the sources for the cities.accumulation in the natural water system， whichW astewater reclamation and recyeling benefit the waterdeteriorates the water environment.resources and water environment, which is the core ofAccording to the concept of social water healthysocial water healthy cycle.cycle, the social use of water must be changed from the3) Return sludge to farmland. The sludge olinear model like “excessive exploitation- →+low efficiencywastewater treatment plants are full of phytonutrients.use- + high pollution emission" into the recycle modelIt is recycled as agricultural fertilizer to comply withlike“restraint use of water →efficient use of water- →the law of nutrient cycling. It is the only way for waterwastewater reclamation, reuse and recycle”。Water re-environment recovery and sustainable agriculturalsourse can be recycled among the cities within thedevelopment.catchment to share the healthy water environment. TH4) Restore urban water hydrological cycle. Re-social water cycle is harmoniously integrated into thestore the natural water cycle approach, build up the in-natural cycle of water.filtration and storage ，eliminate the urban-type flood-ing, and imnrove river fInws and sroundwater levels in5 Theoretical basis of social water healthydry season中国煤化工ctive ways for in-creasing thiYHCN MH G.From Vogt ' s Road to Surival and Carson's Silent5) Strongly reduce surface pollution load. Pro-16 Engineering Sciencesmote eco- agriculture fertilizer and non-toxic, less toxicformerly, to the resources.pesticides, reduce agricultural runoff pollution， and6) Establish a scientific watershed managementchange the human and animal excrement and animalpattern.breeding industry waste in towns, as pollution sourcesContro! the use ofwater and separate thepollution in originEstablish a sqicntifoReusc and recycle thewatershed management下wastewaterWater healthy cycleurfaceSludge return topollution loadfarmlandRestoration of urbanwater hydrologicalFig,4 Strategy of social water healthy cycle and water environment recovery7.2 Revolution of urban drainage system7 Change of urban drainage system andNearly in half a century，population and urbaniza-urban recycling water systemtion together increase fiercely. Water crisis appears in7.1 History of urban drainage systemmany regions. For the restoration of water environment.The rudiment of urban drainage system can beand sustainable use of water resources，drainage systemtraced back to thousands of years ago. The drainagemust be changed. Its function should be elevated to thesystem was used to discharge storm and prevent waterties of recycling and reclamation of wastewater and: re-logging.. Until the 19th century, the water -borne infec-cycling of plant nutrients, and the base of energy andtion spread in cities in Europe, such as cholera whichmaterials recovery.made death of thousands of people. Hygienist thought7.3 Model of urban recycling water systemthe unsanitary conditions as the major factor for infec-In recycling city with the reuse of water and mate-tious diseases. Water fush toilets invented in the 18thrial resources, the reduction, reusing and recyeling ofcentury were populated with the construction of sewagethe consumption can be realized. Its material flow, wa-and . combined sewer system in the 19th century.ter resource system and energy flow should be closed.Sanitation conditions of urban residents were success-Recycling urban water system is the important channelfully improved and the outbreak of water-borne diseasesof water resources, recycling of material and the basiswere avoided. But' the water quality of river declinedof the recycling city. It takes on the important task ofseriously. The Rhine. had been the largest sewer in Eu-social water and the cycle of plant nutrients.rope. People were forced to treat wastewater because ofA city must have a healthy water resources system ,the widespread pollution of river. With the develop-which supplies the water safely and reliably for livingment of wastewater treatment, the modern drainage sys-and production, and collects the miscellaneous water oftem was populated in big cities in last century. W aterhabitat , industrial wastewater, rainwater for recycling,quality of rivers has been improved, while the cosmo-renewing and reusing. There is also a healthy materialpolitan water pollution and eutrophication have not( plant nutrients ) cycle system, which collcts habitatbeen solved fundamentally. In recent years， sewageexcrement and organic waste for farmland after decom-treatment rate has been increased rapidly in cities, butposition by fermenting. The healthy cycle of water re-the water pollution has not been curbed in China. Thesources and plant nutrients constitutes the basis of re-function of urban drainage system developed from rain ,cycling city.中国煤化工er urban groupssewage collection, treatment and elimination to impro-in the sameMHCNMLcle the water ofving urban living conditions and sanitation to preventthe same rivCN M H Gres, rather thanwater pollution.pollute the cities downstream, as shown in Fig. 5.Vol. 10 No. 1 ,Feb.2012 17Food ]AC Farmland ]LConsumeVPNPW aterWater use L__DrainageDischargesystomRecyoledAgriculturalInnovative urban drainage systemProducersConsumerJ Decomposcrs下Nutrient cyelingFig.5 Model of urban recycling water systembuilt, and recycled water use amounted to 360 million m' ;8 Application on the strategic planning ofurban wastewater reuse rate reached 50 %.urban water resources and environmentThirdly, restoration of water environment in theOver the years , under the guide of water recoveryriver and lake. From 2004, the polluted river waterand urban water healthy cycle concept, part of nationalwas annually intercepted, and recycled water was emit-long-term development strategies and planning wereted to river base, so that the water of Qinghe, Liang-finished, and the strategic planning and research workshuihe and Ma Tso River has become clear.n Shenzhen, Dalian, Beijing and the second Songhua2) In 2001，commissioned by the Shenzhen LandRiver basin water environment were also finished.Bureau,“ Shenzhen drainage system planning” was1)In 2004, a key project of Bejjing Educationfinished. Reclaimed water, as the second urban waterCommission,“ water environment recovery engineeringsupply system， wasplanned.The constructedstrategic research ”was finished, which pointed outwastewater plants were upgraded to the reclaimedthat the sustainable use of water resources in Beijingplants, which were the centers to set 5 reclaimed waterand the improverment of water environment can only de-supply system areas. The total amount of renewablepend on the implementation of the Beiing water healthywater supply reached 4. 9 X 10 m'/d and the watercirculation. Renewable water resources can not onlysupply pipe reached 130 km. Renewable water can notmeet the need of urban development of Beijing, but alsoonly solve the problems of the water balance ingreatly reduce water pollution. Based on this research,Shenzhen，but also supply the ecological water. Bio-Beiing Water Authority firstly pursued the “ Waterchemical oxygen demand ( BOD3 ) discharged into theCyele”in China， which has made remarkableriver was reduced 4500 t, and CODc of 12 050 t eachachievements over the years.year. This project will play a significant role in impro-Firstly， full implementation of the saving waterving water environment of the Shenzhen Bay and Dap-policy of government-led. Agricultural water use waseng Bay. This is the first plan on urban reclaimed wa-compressed from 1. 649 billion m' in 2000 to 1.08 bil-er supply system which takes the raw sewage as thelion m' in 2006. During the past few years, the city' ssources supply system. Sustainable use of water resubstantial growth in industrial production was obvious，sources of Shenzhen, improving and restoring the baywhile the industrial. water use revealed' “ negativewater quality and water environment recovery utilitygrowth". The urban saving devices in public placesplay a founder role in major cities across the country.were universal and the water-saving appliances pene-It plays a key role in the recovery of water environmenttration rate of residents reached 80 %.in Shenzhen and also sets a good example for other cities.Secondly, sewage treatment and recycled water3) In 2003, commissioned by the city of Dalian,use. In 2006, the urban sewage treatment capacity in-the document of “Dalian sea water and wastewater re-creased from 1.9 X 10'm'/d in 2004 to 2.5x10*m'/d,sources stratarip" "qp fnishad, It uras clearly pointedand the treatment rate jumped from57.7 % to 90 %.out that中国煤化工:onventional waterThe cut ratio of chemical oxygen demand ( CODc) wassource, sMHC N M H G wastewater reclai-increased from 30 % to 80 %.6 recycling plants wereming reusing and recycling should be firstly developed,18 Engineering Scienceswhich could add a lot of water and solve environmentalthe earth, to pursue the harmony between human soci-problems. It estimated the cost of water of various wa-ety and natural cycle， the basic approach operatingter sources, as the base for government decision. Thesystem of water environment recovery and water healthyeurrent diversion water of Biliu River costs 3.5 Yuan/ ncycle are prensented, forming a system of theory andof Dayang River 5 Yuan/m'. Urban sewage recycledpractice guidelines.water costs 1.11 Yuan/m'，and desalination costs: ) Ecology and system science concepts are ap-6 Yuan/m'. According to the plan, the total size of re-plied. Social activities are researched in the system ofclaimed waterway will reach 7 x 10 m'/d and 2.6 xthe nature. Dualism of nature that human beings think10°m3 fresh water will be supplied annually in 2020，themselves the master of nature should be abandoned.which may waive or delay the diversion from Dayang2) Cycling urban drainage system, with obviousRiver. At the same time, CODa, total nitrogen (TN)environmental and economic benefit, follows the natu-and total phosphorus(TP) will be reduced 25 550 t,ral cycle law of water and the nutrients for plant, har-6400t and 1 300 t respectively, which makesmonizes the recycling of water and material resources,significant contribution to the water recovery.focuses on the separation of waste water from human4) In 2005 , commissioned by the Chinese Acade-habitat excrement and miscellaneous living water atmy of Engineering， the document of“The secondsource, benefits the plant nutrition and use of water ,Songhua River pollution control measures” was finand has strategic significance to improve life and pro-ished. The specific measures are as follows: a. estab-mote the sustainable development of society. Cycle-lish urban healthy cycle strategy of Jilin and Chang-based urban water system and habitat health systemchun Provinces; b. establish water healthy circulationwill be able to obtain a multiplier effect and make sig-system laws and regulations; c. establish the coordina-nificant contribution to sustainable development for hu-ting authority for the Songhua River basin on water en-man society. Under the guide of the circular economyvironment and water resources.and sustainable development， the strategywater5) In 2003,“healthy cycle of urban water sys-healthy cycle is established，with correspondence of 3Rtem”was written into the national long-term scientificprinciple: Reduce, Reuse and Recycle.and technological development strategic studies3)Two aspects of the water crisis: water shortage(2006- -2020). From 2005 to 2020, 15 years in to-and water pollution shall be unitized to solve. Focus ontal, 3 ~5 demonstration projects which take full use ofthe whole process, cut off and separate the pollutantsrecycling water and realize the social water healthy cy-from sources, and change the pollutants into the fertil-cle should be constructed to achieve full water environ-izer that it should have been.ment recovery. The introduction of this strategic means4) Emphasize public participation and set allChina' s water environment recovery is fully acted.forces in society to achieve water environment recoveryand social water healthy cycle.9 ConclusionIn this paper, from the basic law of water cycle onAuthorZhang Jie, male, borm in Benxi, Liaoning Province in 1938, obtained Ph. D from Osaka University in 1985.He is an academician of Chinese Academy of Engineering and mainly engaged in researches on water-supply anddrainage engineering. He has published over 150 papers. He can be reached by E-mail:6282031@ 163. com中国煤化工MHCNM HGVol. 10 No. 1 ,Feb.2012 19