EVALUATION OF WATER AND SEDIMENT QUALITIES AT RIVER MOUTHS IN THE HAIHE RIVER SYSTEM

EVALUATION OF WATER AND SEDIMENT QUALITIESAT RIVER MOUTHS IN THE HAIHE RIVER SYSTEMCheng LIU', Zhao- Yin WANG'2, Yun He', and Dngsheng CHENG'ABSTRACTWater and sediment qualities are studied by analyzing samples taking from the mouths of the Haihe,Duliujian, New Ziya and Beipai rivers in the Haihe river basin in north China in 2005 and 2001, inorder to find the changes of water and sediment pollutions. The concentrations of heavy metals, arsenic,total nitrogen (TN) and total phosphorus (are analyzed and results have been compared for the twotimes. The in-situ measurement for Dissolved Oxygen (DO) and Sediment Oxygen Demand (SOD)rates were crried at the Haihe and Duliujian river mouths in 2006. The results show that the waters ofthe 4 river mouths are still serously polluted, though much improved in the case of the Haihe andDuliujian rivers. The main pollutants are TP and TN in the New Ziya and Beipai rivers and mercury(Hg) at all 4 river mouths. Compared with those in 2001, the concentrations of almost all metals andarsenic in the 4 river mouths have decreased. Water quality at Haihe and Duliujian shows an improvingtrend, while the water quality at Beipai is similar to that of 2001. In contrast, water at the New Ziyariver mouth is more severely polluted. The sediments in the 4 river mouths are not seriously pollutedby heavy metals but are polluted by nitrogen and phosphorus. Most of the pollutant contents in thesediments show ltte change between 2001 and 2005. The in-situ DO and SOD measurement showsthat the waters at the Haihe river mouth is in the state of oxygen depletion, and SOD is importantconsumer of DO at the river mouths. The overall analysis shows that increasing water pllution andeutrophication in waters far from cities are ongoing causes of concern.Key Words: River mouth, Water quality, Sediment quality, Eutrophication, Sediment oxygen demand1 INTRODUCTIONDuring the gh and 10h December, 2005, a field investigation was made to study pollution at rivermouths entering the Bohai Bay in the Haihe River system. Water and sediment samples were collectedfrom the Haihe, Duliujian, New Ziya and Beipai rivers and from the Qikou fishing quay (Fig. 1).Corresponding measurements were made in 200i (Liu et al, 2003a, Liu et al, 2003b, Liu et al, 2003c).The purpose of the 2005 campaign was to investigate the changes in water and sediment pllution at thesites over the 4 year period.The water samples were cllected from within the upper layer of the water column (5-20 cm), and thesediment samples were taken from near the seabed surface (0-3 cm). The concentrations of dissolvedcopper (Cu), zinc (Zn), arsenic (As), lead (Pb), mercury (Hg), total nitrogen (TN) and total phosphorus(TP) were determined to the water samples, and the contents of Cu, Zn, As, Pb, Hg, TN, TP and organicmaterial were determined to the sediment samples by the Tsinghua Analysis Center. The apparatus usedfor determinations included Inductively Coupled Plasma (ICP), Spectrometer and Atomic FluorescenceSpectrometer (AFS). The tests were carried out in accordance with the national standards of JYT015- 1996, GB/T 5009- 1996, GB 7852- 1987 and GB 7173- 1987 (Liu, 1996). .An attempt of in-situ Sediment Oxygen Demand (SOD) rate measurements were tried in the 2005 tripbut were failure due to the bad weather condition and insufficient preparation. In August 2006, theDissolved Oxygen (DO) and SOD rates were measured at the Haihe and Duliujian River mouths, in orderProf, Dr.. International Research and Training Center on Erosion and Sedimentation, Beijing, 10044 China,E-mail: chliu@iwhr.comProf., Dr., Dept. of Hydraulic Engineering, Tsinghua Universit1 Training Center onErosion and Sedimentation, Beijing, 10084 China, E-mail: zy中国煤化工Dr., Senior Engineer, China Institute of Water Resources and HHCNMHG]100044, ChinaNote: The original manuscript of this paper was received in Feb. 20u1. hic TcvIsou veloiun was; received in Marth2007. Discussion open until Dec. 2008.-318-Intemational Joumnal of Sediment Research, Vol. 22, No. 4, 2007, pp.318- 326to investigate the oxygen consumption by the surface sediment in river mouths.2 WATER AND SEDIMENT POLLUTION AT THE STUDY SITES .Water quality was evaluated using the Surface Water Environmental Quality Standards (GB3838- 2002)of China; relevant values from the standards are listed in Table 1. Sediment quality was evaluated usingthe Marine Sediment Quality (GB18668 2002) of China (Table 2) and the Technical Rules of the SecondBaseline Investigation on Chinese Ocean Pollution (TRSBD). The acceptable standards for TN, TP andorganic material in the TRSBI are 0.055%, 0.060% and 3.0% respectively (Xu et al., 2000).Sampling sites"Ri RirhSTianjin1. Haihe R.2. Duliujian R.3. Qingjinghuang R.2Bohai BaySen/Ziya Riv 54. New Ziya R.5. Beipai R.3Canpzhghfo46. Qikou fishing quayFig. 1 Sampling sites (The saellitle image is produced by images from Google)Table 1 Classification of part pollutants in the Surface Water Environmental Quality Standards(GB3838-2002) Unit: mg/]ValueClassIIPollutantsDO7.55_0.020.30.4TP≤(0.01)(0.025)*(0.05)*(0.1)*(0.2)*TN0.20.5.01.52.02u0.011.00.050.1Hg_≤_0.000050.00010.001_Pb0.01 .* for lakes and reservoirsTable 2 Classification of part pollutants in Marine Sediment Quality (GB18668-2002)StandardCu (mg/kg)Zn (mg/kg)Pb (mg/kg)AS (mg/kg)Hg (mg/kg)35.0150.060.020.00.20 .I100.0350.0130.065.00.50200.0600.0250.093.01.002.1 Copper (Cu)Fig. 2 shows that the dissolved Cu concentrations of water中国煤化工nge from 0.002 to0.044 mg/l, which is relatively low. The Cu values at the QMHCNMHGriversandattheQikou fishing quay meet the GB3838 2002 Class II standard, while those at the other 3 sites meet Class I.Intermational Jourmal of Sediment Research, Vol. 22. No. 4, 2007, pp. 318-326-319-The Cu concentrations decreased draicaly-by one order of magnitude at the Qikou fishing quay anda ltte more than one order of magnitude at the Haihe and Duliujian rivers- -between 2001 and 2005.The Cu contents in the sediment samples are similar at the 6 sites, range from 30 to 56 mg/kg. Theirvalues in the Haihe and Duliujian river sediments are a ltte higher than at the other sites, with levelselow GB 18668-2002 Standard II, and the values at the other 4 sites are lower than Standard I. In contrastto water Cu levels, Cu levels in the sediments show litle change between 2001 and 2005.0.2e:3001岂0.04↓00 t小0100n t004000J重，一H山jc.o4Foc12.00Hube Dloju Qapjnphoeg NereZyp Beiqu QicvieDusujan Qupopdang Nrma Brepu QionFig.2 Contents of pllutants in water (lef) and sediment (right) samples2.2 Zinc (Zn)The Zn concentration of the water samples is highest in th中国煤化工2005 value is closeto the 2001 average Zn concentration. The New Ziya water IMYHC NMH Gother 5 sies ranges085 mg/, which islower than the GB3838 -2002 Class II standard. Water sampfrom 0.01 to 0.03 m/, which is lower than GB3838 2002 Class I, and Zn levels have deceased- 320-International Joumal of Sediment Ressearch, Vol. 22, No. 4, 2007, PP. 318 -326noticeably since 2001. The Zn concentration at Qikou fishing quay has decreased nearly by one order ofmagnitude.With the exception of the Haihe river, the Zn content in sediment is similar at all sampling sites, rangingfrom 69 to 99 mgkg, which is lower than GB18668- 2002 Standard I. The Zn level in the Haihe riversediments is very high, reaching 420 mg/kg, which exceeds Standard II but is still lower than Standard II.The Zn content in the Haihe river sediments is almost twice that of 2001, while the Zn levels at the othersites decreased from their 2001 levels.2.3 Lead (Pb)The concentration of Pb in the water samples from the 6 sites is low and similar, ranging between0.0005 to 0.0009mg/l, which is lower than the GB3838 -2002 Class I requirement. The Pb concentrationsin the water samples decreased considerably between 2001 and 2005; 2005 concentrations in theDuliujian river and the Qikou fishing quay are 7.2% and 3.6% respectively of the 2001 concentrations.The Pb content in the sediment samples at the 6 sites ranges from 22 to 33 mgkg, which is much lowerthan the GB 18668 2002 Standard I. Sediment Pb content decreased at all sites between 2001 and 2005.The average value from the 6 samples taken in 2005 is 26 mg/kg, which is a decrease of about a thirdcompared with the average from the 5 sediment samples taken in 2001.2.4 Arsenic (As)The As concentration in the 6 water samples ranged from 0.0013 to 0.0061 mg/, which is much lowerthan the GB3838- 2002 Class I value of 0.05 mg/l. Concentrations of As in the Qingjinghuang, New Ziyaand Beipai rivers and Qikou fishing quay samples are similar, with an average value close to 3 timesthose of Haihe and Duliujian rivers. 2005 levels of As in the Haihe and Duliujian rivers are similar to2001 levels, while As levels have increased in the Qingjinghuang river and Qikou fishing quay.The As content in the 6 sediment samples ranged from 11 to 61 mg/kg. The levels of As in the Dulijianand New Ziya rivers and in the Qikou fishing quay meet the requirement of GB I 8668- 2002 Standard I,while the levels of As at the other sites meet Standard II. Between 2001 and 2005, As content in the Haiheriver sediments increased from 18 to 61 mg/kg, while As levels in the Qingjinghuang and New Ziya riversand in the Qikou fishing quay show a small increase.2.5 Mercury (Hg)The Hg concentrations of the 6 water samples in 2005 are similar, with values ranging from 0.00012 to0.00024 mg/l. The values meet the GB3838 -2002 Class IV requirement. Hg concentrations at the 4 sitesfor which there is both 2001 and 2005 data show a substantial decrease over the 4-year period; Hgconcentration at Duliujian River decreased nearly by one order of magnitude.Hg content in the 2005 sediment samples varies litle across 5 of the sites and has a range of 0.037 to0.062 mg/kg. Hg levels are somewhat higher in the sediments of the Haihe River, with a value of0.11mg/kg. However, all of the measured sediment Hg levels are lower than the GB 18668 2002 StandardI. Compared with 2001, sediment Hg levels have all decreased; the values at the Haihe river and theQikou fishing quay are now roughly 1/3 the 2001 levels.2.6 Total Phosphorus (TP)TP concentrations in the waters of the Haihe and Duliujian rivers are 0.065mg/l and 0.055mg/lrespectively, which are below the GB3838 2002 Class II level. The 2005 concentrations are about 1/2 and1/5 respectively the 2001 levels. TP concentrations at the other 4 sites have increased dramatically since2001, with values in 2005 far exceeding the GB3838- 2002 Class V standard. TP concentrations in thewaters of the Qingjinghuang and New Ziya rivers are extremely high, with values of 1.85mg/ and2.98mg/l respectively, that is 4.6 and 7.5 times the Class V level. The water colour of the Qingjinghuangand New Ziya rivers is black and the water looks like sauce at the Qikou fishing quay. The water smellsfoul at these 3 sites.中国煤化工Sediment TP content at the 6 sampling sites show smal三.056- 0.088%. Thevalues show only small changes since 2001. TP contentYHc N M H Gikou fishing quaysediments are lower than the TRSBI standard, while those at the other 4 sampling sites are slightly higher.Intemational Journal of Sediment Research, Vol. 22, No. 4, 2007, pp. 318- 326-321-The highest value of 0.088% occurs in the New Ziya river sediments.2.7 Total Nitrogen (TN)TN concentrations in the waters of the Haihe and Duliujian rivers are lower than 0.02 mg/l and thereforemeet the GB3838- 2002 Class I requirement (for lakes and reservoirs). TN concentrations in the waters ofthe Beipai river and Qikou fishing quay are 0.026 mg/, which meet the Class II requirement.Concentrations at these 4 sites have decreased considerably from the 1.9 2.5 mg/l values in 2001. TNconcentrations in the waters of the Qingjinghuang and New Ziya rivers are extremely high, with values of70 mg/l and 19 mg/l respectively. These levels are close to the average high and low TN concentrations ofthe inflow adopted in municipal sewerage treatment plants designs (Zhang et al.. 2000). The very high TNconcentrations are due to the local severe water pollution caused by sewerage near the sampling sites.Sediment TN content shows small variation across the 6 sites, ranging from 0.078 0.1 1%. AlI the valuesexceed the TRSBI standard for TN, and represent relatively serious nitrogen pollution in the sediments.Compared with 2001, sediment TN content at the sites shows ltte change, except in the Haihe riverwhere sediment TN has decreased slightly over the period.2.8 Organic MaterialOrganic material content in the sediments shows lttle variation across the 6 sites, ranging from 1.23 -1.88%. All of the values are lower than the TRSBI standard for organic material. Compared with 2001,sediment organic content has changed lttle in the 4-year period, except at the Haihe and Duliujian riverswhere some decrease in organic content was observed.3 EVALUATION OF WATER AND SEDIMENT QUALITIES AT RIVER MOUTHSThe locations of the Qingjinghuang, New Ziya, Beipai and Qikou sampling sites are shown in Fig. 3. Itcan be seen that the Qinginghuang and New Ziya sites share one river mouth, and that the Qikou fishingquay is actually located on the Beipai river. So, the measurements from the 6 sites represent the quality ofwater and sediment at 4 river mouths of the Haihe river basin. In the following analysis, results for theNew Ziya river mouth are based on the average of measurements from the Qingjinghuang and New Ziyasites; results for the Beipai river mouth are based on the average of measurements from the Qikou fishingquay and Beipai river sites.Fig, 3 Satllite images of the samping sites on the Qingjinghuang and New Clya rivers (lett)and on the Beipai river and Qikou fishing quay (right)3.1 Evaluation of Water QualityThe state of water pollution at each river mouth is evaluated using the Comprehensive Water PollutionIndex (K) and GB3838- 2002. K is defined:K=Sac中国煤化工in which Ck is the maximum comprehensive allowance indeMYHCNMHGentohaveavalueof 0.1; C; is the measured concentration for each pollutant; and Cor is the upper limit concentration of each- 322-International Journal of Sediment Research, Vol. 22, No. 4, 2007, pp. 318- 326pollutant for the corresponding surface water according to certain standard. In the analysis, the waters areconsidered as GB3838 -2002 Class IV surface waters, and Coi uses the upper limit values of the Class IV.The water is clean when K<0.I, slightly polluted when K=0.1-0.2, polluted when K>0.3 and seriouslypolluted when K>0.3(Zhang et al, 2000,). Table 3 lists the calculated Comprehensive Water PollutionIndex (K) for the 4 river mouths in 2005 and 2001.Table3 Evaluation of water and sediment pollution at river mouthsHaihe R.Duliujian R.New Ziya R.Beipai R.Water_ SedimentWaterSedimentWater| SedimentCuIZnIIPb1AsHgIVVTP_>>VOrganic material<__EvaluationII_Main pollutantsZn, P, N_HgP.NHg.PNP, NHg, PNComprehensive0.053.820.27water pollution0.260.390.200.36Index K(2005 /2001)Index of trophic4645963state (2005/2001)6572The K values presented in Table 3 show that the waters of the Haihe and Duliujian river mouths can beclassed as“clean”in 2005 compared with“polluted" and“seriously polluted" respectively in 2001. TheNew Ziya river mouth changed from“slighted polluted" in 2001 to "seriously polluted" in 2005, whilethere has been no change in the“polluted" condition of the Beipai river mouth between 2001 and 2005.Evaluated against GB3838- 2002, it can be seen that the waters of the Haihe and Duliujian river mouthsmeet the Class IV requirement. The main pollutant is Hg while the concentrations of other pollutants arelower than the Class II values. Water quality in terms of TN and TP at the New Ziya and Beipai rivermouths is much worse than Class V. Hg concentrations at these 2 river mouths meet the requirement ofClass IV, while the concentrations of other pollutants are below the Class II levels. Compared with 2001,the concentrations of almost all pollutants have decreased significantly; the exceptions are the TN and TPconcentrations.3.2 Evaluation of EutrophicationNo generally accepted standard or evaluation method exists for the degree of eutrophication. In thispaper, the degree of eutrophication is evaluated using the Eutrophication Evaluation Standard forNational Integrate Water Resources Planning, as presented in Table 4 (Tsinghua Univ., 2005). The degreeof eutrophication of waters is presented by the average index based on the concentrations of TP, TN andchlorophyll. The trophic state for waters are: Oligotrophic when 0 < Index≤20; Mesotrophic when 20