Water quality characteristics of rivers and ponds in Japan

Journal of Harbin Institute of Technology (New Series), Vol. 11. No. 5, 2004Water quality characteristics of rivers and ponds in JapanYuhihiko TAKAHASHI' , DU Mao-an'，Michinmasa NAKAMURA'高橋幸彦，杜茂安，中村玄正(1. Schnud of Municial aund Enviomenal Engneening, Harbin Insiute of Technlog , Harbin 150000 , China, F-mai :dumoum@ sohu. cum;2. Depl. of Civil Engineeing, Clle of Enginering, Nihon University, Fukushima ken 963 8642, Japan)Abstract: In Japan ,various countermeasures have been taken to improve the water quality of publie waterssuch a5 rivers and lakes. Though water quality has improved, it is sill inufcient.. In summer, eutrophicationis seen in'lakes and inner bays, as well as rivers. As a countermeasure to prevent eutrophication, the removal"treatment of nutrient salts such as nitrogen and phosphonus is done, in addition to organie substance eliminationin the domestic sewerage system. This report will showquality characleristics of rivers and ponds inJapan. It is considered that these investigative results are efctive when the water quality improvement of thestabilization ponds where eutrophication occurs are examined in China.Key words: water quality charateristics，eutophication , nitrogen and phosphorus, stabilization pondsCLC number: X143Document code: AArticle ID: 105-9113( 2004 )05-0501 _05After an advanced economic growth term afterplains in the Nakadoori district of Fukushima Prefecture1960，it was considered urgent to improve domesticinto the Sendai Bay. Its length is 239 km, the drainagesewerage systems and enforce measures either to regu-area is approximately 5 400 km2 and population in thelate the amount or quality of industry wastewater to bearea is about 1 400 000.discharged into the rivers in Japan. That wastewaterExperiments were conducted in the Abukuma Riv-eriterion value is 20 mg/L of BOD, 70 mg/L of ss ander and its tributaries which are located approximately 403 000 cells/mL of Coliform Organisms. Water qualityto 100 km upstream from the river mouth ( as shown inof public waters, such as rivers and lakes, showed an Fig. 1). Observation stations were set up at Sta 1 to Staimprovement tendency with the diffusion of the treat-6 in the river and Sta 7 to Sta 12 in its tributaries.ment system. The achievement rate of the environmen-tal standards is 82. 4% of rivers, 42. 3% of lakes andreservoirs, and 75. 3% of coastal waters in 2000. Spe-cially, the achievement rate is low in enclosed bodiessuch as lakes, reservoirs, inner bays, and inland seasV\Inawashi( especially the east part of Seto Inland Sea).Koriyama CityAl present, the diffusion rate of domestic sewerage❹systcm is 62% and cannot deal with all the domesticwastewater which it does not gather in. Moreover, ifs.tAssukuguwa City,advanced wastewater treatment is not done, removal ofnutrient salts such as nitrogen and phosphorus cannotThe Abukuma riverbe fully achieved, and the eutrophication phenomenon.1L.3orurs in lakes and inside bays in summer.The authors. investigated the water quality charac-ityt.8teristics of rivers" and ponds' 5 at the Abukuma riv-05_1015 203er basin in Japan. In the river investigation, nitrifica-kmtion activities of biofilms grown on riverbed gravel wereexamined. And, in the ponds investigation, the sea-sonal changes of pond discharge and the quality of theFig.1 Observation stations in the Abukuma river and itsfish breeding ponds were exarmined.tributaries1 Rivers Investigation中国煤化工sic sernge syulem1.1 Study Areaaround:YHCNMHGbout40%，anditisThe Abukuma River flows through the alluvialthe area where diftusion is delayed in the country. The .Heceive! 2003 - 10 -21.501.Journal of Harbin Institute of Technology (New Series), Vol. 11, No. 5, 2004sources of pollution load in the Abukuma River arerapidly deteriorate.livestock farming, domestic wastewater, and farmland;Practically no pollution sources were observed atit was found that livestock farming contributed aboutSta 1, an upstream point of the river ，and water quality70% of the pollution load generation in the basin.was good. The main sources of pollution load at this1.2 Water Qualitypoint were woods. However, the river often receivesWater quality in a natural environment is generallythe effects of domestic wastewater because seweragegood, because it is artificially polluted. Pollution loadsystems are not yet well developed in Shirakawa City.generation in a natural environment is relatively small.And, the influence of the livestock farming ( cattle andIt is smaller than the self- purifcation capability of apig) is large as well. At Sta 7 and Sta 8 in the tributa-river. On the other hand, once the influence of artifi-ries, water quality was very bad. .cial pollution due to the progress of urbanization andIn the Abukuma River basin, there is a large a-industrialization in the river basin becomes larger andmount of pollution load generation. Pollutants easilythe pollution load generation exceeds the self-purifica-flow into the river and there is a tendency of watertion capability of a river, the river environment starts toquality to continuously worsen ( as shown in Tab.1).Tab. 1 Flow conditions and water quality of the abukuma river and its tributariesFlowBODNH4-N NO2-N NO3-N T-NNH4-N NO2-N NO,-N T-N/(m3.s-1) /(mg.1-) /(mg.1-I) /(mg.1門) /(mg.1"I) /(略*11) /(kg .day -)/(kg . day -1)/(kg . day -1)/(kg .day -1)/(kg.day-")Sta 12.41.00.030.010.540. 6819754111214Sta .9.00.070. 020.760.91! 656591708Sta 3202.90.041.502.66501159122 5924 596ta 4250.021.432.366 35043830895098.tζ293. 589 1710758Sta6381.701.989 52113155816 501Sta71.90.06.1.31538.0200215Sta80.62.50.180. 132.352. 66127122138Sta91.34.13.083.55461346399Sta102.20.08.1.391.661 9402:237I477.Sta 116.43.50.081.031 9134570829Sta 123.11.261.52665g723281.3 Nitrification Activityter temperature was controlled at 20 9C.Using biofilms developed on riverbed gravel, itsThe concentrations of ammonium oxidizing and ni-characteristics and riverbed material were examined.trite oxidizing bacteria were estimated in the sampleThe activities of biofilms on riverbed gravel located atused for the experiment. It was analyzed by using thethe rifle zones were investigated.Monod kinetics model.The biofilms repeat growth and exfoliation everydXa = (μ-kJ)x,(1)day, and conformation inside the biofilms is very com-plicated. During summer and winter, the conformationX = Xo+ Y(So-S)，(2)of bioflms varied due to the influence of water temper-HmS(3)ature and rain fall, and the difference of the presenceks +S'amount between the heterotrophism bacteria and the ni-dum SXtrification bacteria in periphyton biofilm on the riverbedK's + S'(4)was observed. The amount of exfoliation of biofilm fromthe riverbed deposits is relatively small when river flow=一In{1 +二(So-S)1,(5)is30 to40 m'/s. On the other hand, when the riverwhere S is substrate concentration ( mg/l) ; saturationflow is larger than 100 m'/s, it is observed that a largeconstant ( mg/l);μ is specific growth rate (l/h);μm isamount of biofilm exfoliation occurs.maximum specifie growth rate (Ih); hg is extinctionNitrification activity examination is as follows.cofficient of bacteria (Vh); X is bacteria concentra-The initial concentration of the ammonium nitrogen andion ( mg/l); Y is growth yield coefficient of bacterianitrite nitrogen was adjusted to 20 mg/l. .Then，the中国煤化工scriptO is first run in aammonium oxidation of the batch tests was added until240 mg/l with the solution of NaHCO3(1 g/l). In or-9HC N M H Gowth raltes were deidedder to obtain the release rate of the ammonium nitro-upon as being 0.013 I/h for ammonium oxidizing andgen, the experiment of adding ATU ( allylthiourea) of0.020 l/r for nitrite oxidizing bacteria respectively.5 mg/l was conducted to control nitrification. The wa-The growth yield coefficients were decided upon as be-.502●Journal of Harbin Institue of Technology (New Series)， Vol. 11, No. 5, 2004 .ing 0.098 mg-cell/mg-N for ammonium oxidizing anddistance is short.0.017 mg-cell/mg-N for nitrite oxidizing bacteria re-When the nitrogen self-purification action occurs,spectively.oxidization of ammonium nitrogen and nitrite nitrogenThe curve computed by the experiment values andprogresses after oxidization of the organic substance inthe curve obtained by the simulation method are wellthe polluted river.corresponding. The concentration of the most suitableammonium oxidizing bacteria could be estimated fromTab. 2 Estimated concentrations and oxidation rates ofthese curves ( as shown in Fig. 2). In the sameman-ammonium oxidizing bacterianer, the concentration of the most suitable nitrite oxidi-Bacteria concentrationOxidation of rate of bacteriazing bacteria can be estimated by the curve that conver-Sample/(mg●/(mg.(g- /(mg* (m2●/(mg" (g-ges using the lapse time of the nitrite concentration andm~2)VS)-i)g)-l)vS.day)-1)the curve to be obtained by the simulation. In the nitri-fication examination by the batch culture, the assess-Sta 125.812. 98241ment of the amount of bacteria activities could be quan-52.8168122.13.70titatively made.Sta437.73..12Sta549.24.61552:Sta660.55.71938Xa:0.25 mg/1. Xo:0.05 mg/lSta54.33.81732Sta 88.92102820L .----o:1.00 mg/小-Sta976.9245Sta 1021.87.6Sta1l60.419226Sta 1232.310170tTab.3 Estimated concentrations and oxidation rates of ni-trite oxidizing bacteriaBactenia concentration/(mg. /(mg.(g- /(mg. (m2●/(mg" (g-m-2)VS)-')day)-I) VS ●day) 1)S0015020025030(0Sta 2Fig.2 Consumption curve of the substrate of ammoniumSta 30.20.9oxidation by riverbed gravelSta 40.2S2.2Sua50.7.0.12(The amount of nitrification bacteria, the area den-Sta 6sity, and VS were calculated by using the value of 1/2Sta7Sta8of the surface area of the riverbed gravel as shown inTabs. 2 and 3. Estimated oxidation rates of ammoniumoxidizing and nitrite oxidizing bacteria were calculatedSta 110.60.1by using Eq. (6):.1315.0R = Pox= x24,Nitrification activity examination using the degra-where R is oxidation rates of armmonium oxidizing anddation of periphyton biofilms found a large amount ofnitrite oxidizing bacteria, Po is ammonium oxidizingammonium nitrogen supply during batch tests. F romand nitrite oxidizing bacteria density or bacteria athe ATU test result, the release of ammonium concen-mount.tration was in the range of0. 2 to 0.9 mg/l. Therefore ，Ammonium oxidizing bacteria indicate a tendencyit can be concluded that the release of ammonium con-of being high at Sta 8 and Sta 9 in the tributaries of thecentration from biofilms grown on the riverbed gravel isAbukuma River as shown in Tab.2. From this tenden-very large in urban rivers. Thus, released armmoniumcy, it is considered that the ammonium oxidizing bacte-concentration may affect the nitrification of the river.ria are very active because the total nitrogen concentra-中国煤化工was estimated whention in the tributaries is quite high, 2.7 1o3.6 mg/l astheinsported distance wasshown in Tab. 1. However, the concentration of nitrite1 00CHCNMHGheriflezonestotheoxidizing bacteria was almost zero as shown in Tab.3. .pool zones was 10 to 0. Approximately 4.9% of the a-Generally, perfect nitrification does not proceed in themount of ammonium nitrogen transported in the riverAbukuma River tributaries， because the transportedwas assumed to be annually oxidized by nitrification in●503●Journal of Harbin Institute of Technology (New Series), Vol. 11, No. 5, 20041 km section of the river.posed almost entirely of cells of Microcystis. Algal pro-duction was not limited in summer at ponds by nitrogen2 Fish Breeding Ponds Investigationand phosphorus, the NP ratios of the water were within6.3~10.7. Fig. 4 shows the relationship between re-2.1 Study Areatention time of water in ponds and total nitrogen, totalAt present, there are twenty nine ponds in whichphosphorus and chlorophyll-a concentration. In gener-carp are bred every year in Koriyama City. Eighteen ofal, a certain period of time is required for algae towhich are situated within the basin of the Sasahara andgrow; eutrophication tends to take place in lakes andMinami rivers. The carp breeding has increased sincereservoirs where the retention time is more than 3 to 4the later half of the 1960s. Production of carp was re-days. In ponds where the retention time of water wascently estimated at about 1 400 ton/ year.more than 10 days, chlorophyll-a concentration rangedIn order to make it clear whether water pollutionfrom 7.6 to 692. 5μg/l. When the retention time ofproblems exist in each pond, the eutrophic state ofwater was less than 3 to 4 days, chlorophyll-a concen-twelve ponds in Koriyama City was investigated. Thetration ranged from 8.5 to 217. 8μg/l. Thus, in. carpcharacteristics of seasonal variation of water quality abreeding ponds, the effect of the retention time of watercarp breeding ponds flowing into the basin of the Abu-on the growth of algae was not acknowledged. Judgingkuma River were observed. Sampling sites are shownfrom these facts ，feed beyond the necessity may bein Fig. 3.15Nt s●The Minami●p Koriyama全1曾25The Abukuma, river1e SasaharaKoriyama GityriverLL234km)HRT/day00T 000●94.10095.4■95.60 95.7▲95.80* 95.9●95.100 95.11x* 95.12Fig.3 Sampling sites at the Sasahara and Minami rivers32.2The Water of Efluent from Fish BreedingPondsAbnormal algae growth caused by nutrients whichare heavily included in carp feed results in acceleratedeutrophication in carp breeding ponds every year. Thewater quality flowing into the ponds is very good, be-cause it is taken from Inawashiro Lake of acid lake.However, the water of effluent from the ponds contains100high nitrogen， phosphorus and chlorophyll-a， that●"94.0*95.4 : r95.6 o 95.7▲95.80:95.9◆95.10 095.11 x95.12flows into rivers.800In fish breeding ponds, T-N and T-P concentra-70tions tend to be high in the summer , however they werelow in the spring and late autumn. T-N concentrationr600.ranged from 0. 65 to 11.5 mg/l，the average of T-Nf 500.。，400was4. 28 mg/l. T-P concentration ranged from 0.01 to; 3002.19 mg/l, the average of T-P was 0. 45 mg/l. Chlo-s 200rophyll-a concentration ranged from 7.6 to 692.5 μg/名。o%10I, the average of chlorophylI-a was 143.0 μg/l. As aresult, quite a few ponds were found to be highly eu-0.HRT /daytrophic. The average of pollutants as effluent from one中国煤化工0.95.9◆95.10 9.1 x9.12_daypond was estimated at 0. 34 kg/ day chlorophyll-a,49.3 kg/day carbon, 10. 6 kg/day nitrogen and 1. 07.JHCNMHG_retentionof water inkg/day phosphorus，respectively.ponds and total nitrogen, total phosphorus andThe highest blooming was seen from summer tochlorophy11 - a concentrationsearly autumn. The scum of blue-green algae was com-●504●.Journal of Harbin Institute of Technology (New Series), Vol. 11, No. 5, 2004thrown into the ponds by fish breeding. Therefore, or-ship is easy too. There is seldom the constraint of theganic substance ，nitrogen ，phosphorus will accumulatesite area of the treatment facilties in comparison within the ponds. The release of nutrients from sediments isJapan and China. If it can be suitably dealt with, theconsidered to be a pollutant source in ponds, as T-Nelimination of the nutrient salts is possible by the al-and T-P supply is always abundant. For preventing thegae.occurrence of algal bloom, the input load of nutrientHowever, it should be noted that the activity ofsalts must be decreased in ponds.the algae is lower with the decline of the water temper-In the future, the proper production will be done，ature, and there is the release of nutrient salts ( NH4-and proprietors have to use low protein feed immediate-N, P02-P ) from the sediment of the stabilizationly. And it is necessary to examine purifiers such as anponds. The authors conducted the study of the self-algae elimination device. The water quality of the Sasa-purification of nitrogen in the rivers, and fish breedinghara and Minami Rivers can be improved using thisponds on eutrophication were investigated. It is consid-countermeasure.ered that these investigation results are effective whenthe water quality improvement of the stabilization ponds3 Conclusionwhere eutrophication occurs are examined in China.The stewardship technique of the stabilizationRivers and lakes are regarded as very precious re-ponds and the exclusion method of the algae are exam-sources from environmental as well as use purposesined to prevent eutrophication in the future.when quality is maintained at a sufficient level. In Ja-References:pan, in lakes such as Kasumigaura Lake and SuwakoLake, dense blooms of blue-green algae ( mainly Mi[1] TAKAHASHI Y, SATOU Y, KUROSAWA K, et al.crocystis and Anabaena) appear every year. In theseSelf- purification of nitrogen in middle area of urban riverlakes, carp breeding is done, it is one of the importantbasin[ J]. Joumal of Japan Sewage Works Association,2000 ,37(451):129- 143.nutrient and chlorophylI-a loading sources.MAKINOSE H, TAKAHASHI Y, NAKAMURA M. Ex-The diffusion rate of domestic sewerage in Chinapetimental study on self-purification of nitrogen by atta-is about 15%，and it is low in comparison with Japan.ched algae in a tidal area[ J]. Jourmal of the Japan SocietyTherefore, when rivers always receive the effects of do-of Civil Engineers , 2003.mestic wastewater, industry wastewater and farmland,[3] NAKAMURA M，TAKAHASHI Y, NARITA D, et al.organic material, nitrogen and phosphorus concentra-Efect of efluents from fish breeding ponds on eutrophica-tions tend to be higher. The biological treatment that ation of the abukuma river[ J]. Joumnal of the Japan Societyof Civil Engineers, 1995, 32 :263 -271.treatment cost is cheap and ecosystem is used is con-[4 ] Japan Sewage Works Association. Standard Method for thesidered to be an important sewerage system for theseExamination of Wastewater[ M]. [ s.1.]:[s. n.],materials removal. Recently, water quality purification997.is done by a dam surrounding part of the ponds and[5] EPHA. Standard Method for the Examination of Waterlakes as a stabilization pond in many areas. This meth-and Wastewater[ M]. W ashington D. C: American Publicod resolves organic substance and nutrient salts biologi-Health Association, 1989.cally by collcting polluted water. Conformation is eas-iest in the sewage treatment, and maintenance steward-中国煤化工MYHCNMHG●505●