The results showed that the oil content in sediment ranged from 55.8×10-6 to 2563.4×10-6 , the average is 555.82×10-6, which is 1.05-5.13 times than the standard of Marine Sediment Quality (GB18668-2002).
The organic carbon,sulfide and DO of sediment in bottom water in cage fish farming area exceeded the standards of first class of Marine sediment quality and the second class of sea water quality for fisheries in China,with exceeding rate of 90.9%,100% and 62.5%,respectively,while those in control area were 76.2% and 14.3% and 20.0%,respectively.
Of seven key evaluation elements, i.e., As, Cd, Hg, Cr, Cu, Pb,and Zn, the environment background value is high at large. The background value of Cr and Cu is close to top limited value of No. 1 grade according to standard of national marine sediment quality.
The results showed that the oil content in sediment ranged from 55.810~(-6) to 2563.410~(-6), which is 1.055.13 times than the Standard of Marine Sediment Quality (GB 18668-2002). The average is 555.8210~(-6). The ratio of samples number exceeded to the standard is 50 per cent.
Sediment quality in waters not only affect the benthic organism, but also has close relation with the water quality due to the frequent pollutant interchanges between the sediment and overlaying water. The polluted sediment often becomes the potential source to pollute waters.
In this paper, the authors introduce the evaluation methods in common use for sediment quality and list several kinds of representative sediment quality standards.
The results indicated that concentration ranges of Ni and Cd were 19.9~41.4 mg·kg -1 and 1.19~1.67 mg·kg -1 . According to Sediment Quality Guidelines, Wenyu River sediment was moderately contaminated by Cd and Ni since their concentrations were just between LE-L (Lowest effect level) and SE-L (Severe effect level) values, which may result in negative biota effects in the watersheds.
The results showed that the average contents of organic matter, TN, TP and sulfide of the sediments in the culture areas were respectively 1.23—2.12, 1.33—2.79, 3.71—9.99, and 3.02—11.84 times higher than those in the natural areas, and the longer the culture time was, the worse the sediment quality was.
Two major conclusions are: (i) generalizations are not [yet] possible regarding sediment quality; (ii) correctly assessing sediment quality is primarily a function of the correct reference comparison.
The sediment quality criteria(SQC) development efforts have been undertaken mainly by the United States Environmental Protetion Agency for the assessment of environment impact of sediment-associated pollutants in the latest decade. In this paper, we discussed some problems on SQC,involving 1) the sensitivity of benthic species;2) the numerical and responsive criteria; 3)some intial methodological approaches to generating SQC, especially the sediment/ pore water equlibrium partitionin...
The establishment of sediment quality criteria for heavy metals is becoming a more urgent problem. The importance and applications of this project is reviewed in this paper. The emphasis is on the assumptions, advantages and disadvantages of seven approaches. Current research and perspective of this project are discussed also.
Developing marine sediment environmental quality criteria is the prerequisite for formulating its environmental quality standard. About 20 years'overseas study has established a series of effective approaches in this field. Each of the approaches has its own advantage and can be supplemental to each other. The Apparent Effects Threshold (AET) method, which is considered as possessing potentialities, is an approach through which comprehensive sediment quality threshold is determ...