Distribution Characteristic Of AVS In Sediments Of The Yanghe Reservoir, Shijiuhu Lake, Dongqianhu Lake And Yixingsanjiu Lake

Sediment is not only the reserve of pollutants, but also the potential source ofpollutants which has influence on environment.Recently. The acid volatile sulfides (AVS)in sediments are available for binding heavy metals by formatting insoluble metal-sulfidecomplexes, thereby controlling the bioavailability of heavy metal, so the issue of heavymetal bilavailability of aquatic sedinents is becoming one of the popular matters in theresearch of heavy metals in water environment.This study chooses Yanghe reservoir, Shijiuhu lake, Dongqianhu lake andYixingsanjiu lake as my research object. Acid volatile sulfide (AVS), the simultaneouslyextracted metals (SEM) and organic matters which are main physical and chemical indiceshave been analyzed and heavy metal bioavailability of sediments from these reservoir andlakes has been estimated by AVS and SEM. The features of plane distribution and verticaldistribution of AVS and SEM, along with influence factors have been preliminarilydiscussed discussed. Results have been obtained as follows:1. The vertical distribution regularity of AVS in sediments from Yanghe reservoir is asfollows: the areas of high concentration are the lower reaches of the river and the center ofthe reservoir in spring; it is only area of high concentration in the center of Yanghereservoir in autumn.Through correlation of AVS, OM% and anaerobic environmentalcondition in surface sediments in different seasons, the resultes shows the concentration ofOM% in sediments and anaerobic environmental condition have great influence on thevertical distribution of AVS.2. The fluctuation of SEM in surface sediments from Yanghe reservoir is higher inautumn than in spring. The concentration of SEM in surface sediment of He.4 and He.5 arehigh. As for the composition of SEM, the amount of Zn is the largest and Cd is thesmallest.3. Comparing with the features of AVS and SEM in sediments with different depth attwo separate locations in the reservoir, we obtained following results: The AVS peak isdeeper in sampling location of reservoir.1 than that in sampling location of reservoir.3.Tthemajor cause is that anaerobic environmental condition is different in two locations. Thevertical distribution of SEM is decreasing with depth in these sampling locations.4. In 10 samples, it is only river.2 that 5>SEM-AVS>0, and the other samples are allSEM-AVS<0. The data of AVS and SEM are analysised using SEM/AVS method. Theresults showed that: there is only river.2 reaches the Biology Damage Threshold in autumn; the data of SEM/AVS from other samples are much less than 2.34. Though the(SEM-AVS)/foc ,it is founded that the data of all samples are much less than the BiologyDamage Threshold. Our conclusion is that it is impossible for heavy metals from surfacesediment of the river and the reservoir to induce heavy metals toxicity.5. The concentration of AVS and SEM in surface sediments from Shijiuhu lake,Dongqianhu lake and Yixingsanjiu lake which are in the South have been analyzed. Theresult of experiments showed that the avaverge concentration of AVS from high to low isShijiuhu lake >Dongqianhu lake> Yixingsanjiu lake. It shows that the concentration ofOM% in sediments plays important role in the vertical distribution of AVS.The avavergeconcentration of SEM from high to low is Yixingsanjiu lake>Shijiuhu lake>Dongqianhulake.The centents of heavy metals in surface sediments has mainly influence on the verticaldistribution of SEM..6. Comparing with the features of AVS and SEM in sediments with different depth inthree lakes, we obtained following results: The AVS peak is deeper in sampling location ofDongqianhu lake and Yixingsanjiu lake than that in sampling location of Shijiuhulake.Tthe major cause is that the concentration of organic matter is different in these lakes.The vertical distribution of SEM is decreasing with depth in these sampling locations.Theresultes shows the concentration of organic matter in sediments has great influence on thevertical distribution of AVS with depth.The concentration of SEM is low and the verticaldistribution of SEM is decreasing with depth in these sampling locations.The concentrationof SEM increases remarkably at 25cm from sediments in Yixinsanjiu.7. In 7 samples from Shijiuhu, there are all SEM-AVS<0, the heavy metals in thesesediments are safe for limonitic organisms.The all samples from Shijiuhu lake andDongqianhu lake are all 5>SEM-AVS>0, it is possible for heavy metals from surfacesediment of these lakes to induce heavy metals toxicity.8. The concentration of organic matter in sediments and anaerobic environmentalcondition play important role in the vertical distribution of AVS.The avavergeconcentration of SEM in surface sediments from Yixingsanjiu lake are higher than that insurface sediments from Shijiuhu lake ,Yanghe reservoir and Dongqianhu lake, it showedthat the heavy pollution is seriouser in Shijiuhu lake, Dongqianhu lake and Yixingsanjiulake than that in Yanghe reservoir. The concentration of SEM in surface sediments ishigher than that in deep sediments from sample, the experiment shows that heavy metal pollution is increasing.