This thesis is focused on the impacts of waste dumping on water and sediment quality in the dumping area of the Yellow Sea from 1988. The environmental variables and parameters of the dumping and reference areas in the Yellow Sea were measured during ...
This thesis is focused on the impacts of waste dumping on water and sediment quality in the dumping area of the Yellow Sea from 1988. The environmental variables and parameters of the dumping and reference areas in the Yellow Sea were measured during July 2009 and analyzed.
In the study area, density stratification defended greatly on temperature rather than salinity. Yellow Sea Bottom Cold Water were found below 7℃ at the depth of 30m in all the observation points. The vertical distributions of salinity showed a sudden drop of 0.5∼1.5psu at the 20m depth. It seemed to be influenced by an increase in summer precipitation and also a southward shift of the Yellow River.
The chemical environment of the study area showed that deeper water has low pH, high SS and COD, low DO and an accumulation of nutrients in the bottom layer. Most notably, phosphate values at the bottom were higher than the reference area. The reason for the increase appears to be due to the disposal of livestock, sludge, excreta from 2002, rapid consumption of nitrogen and slow biogeochemical circulation. The data also suggests a eutrophic state is occuring at the bottom layer.
Sediment COD values exceeded 20㎎O2/g-dry, Japan Fisheries Environmental Standard, at stations 3 and 5. The concentration of Cr exceeded ERL(effect range-low) of the NOAA at station 3 and 4. It seems to be influenced by leather process wastes.
The correlation coefficients among the water content and Co, Cr, Cu, Fe, Hg, Ni, Zn concentration in the study area were very high. So, they are staying as dissolved matter.
The average concentration of TIN and phosphates at the bottom layer below the thermocline had incersed from 3.7μM to 9.8μM and from 0.5μM to 1.1μM, which correspond to 2.6, 2.2 times accumulation in the dumping area before 1988.
Continued disposal of waste into the Yellow Sea has impacted the northwest reference area(st.1) as a result of organic oxidation and heavy metal diffusion. In addition, at the station 3, the concentration of Cr exceeded the ERL(effect range-low) of the NOAA. Therefore, station 3 seems to need a rest zone appointment.