Surface sediment samples were collected from lakeside zone of Zhushan Bay, Lake Taihu, of which 10 samples were collected from the littoral zone and one sample was collected from the center of the lake. The concentrations of 16 US EPA-priority-controlled polycyclic aromatic hydrocarbons (PAHs) were analyzed by GC-MS. The results showed that PAHs content varied from 61.2 to 2 032.3 ng/g, and the mean value was 1 131.5 ng/g. The spectra of PAHs showed that 4 rings and 5-6 rings were predominant ones in littoral zone, accounting for 28.6% and 60.9%, respectively, while 2-3 rings PAHs were predominant in the center of the lake, accounting for 88.1%. The source of PAHs in littoral zone sediments was mainly attributed to high-temperature combustion of coal, oil and other fossil fuels, but that in center of the lake was mainly attributed to oil spill. No significant PAH ecological risk was found in littoral zone of Lake Taihu according to ecological risk assessment. However, some PAH concentrations exceeded the effects range low (ERL) in some sampling sites. Potential harmful effects on organisms might exist, and ecological risk should be prevented.
New emission standards in various industries have been enacted to put forward higher requirements towards the desulfurization and denitration equipments. The characteristics and application prospects of the existing pollution control technologies were analyzed and summarized. It is found that the existing main desulfurization and denitration technologies have many defects, such as regional ecological environment damage, production of new solid wastes, and competition for ammonia resource with agriculture, which is not exactly fitted to the needs of China’s national conditions and pollution control requirements. Therefore, the integrated technology of desulfurization and denitration with commercialization of by-products should be the main development trend for coal-fired flue gas. The technology can manufacture sulfuric acid, nitrate and nitrogen fertilizer with SO2 and NOx in the flue gas, so as to make up for China’s shortage of sulfur resources and avoiding waste of ammonia resources, and to provide a useful supplement for the agricultural fertilizer industry.
Since the Liao River basin eliminated water quality worse than class V for COD in the mainstream in 2009, the water pollution control has acquired breakthrough progress. Currently, in accordance with the five main indicators of surface water (COD, NH3-N, BOD5, DO, pH) detection, the water quality has reached class IV and been relatively stable, the fish has been restored to 40 kinds, and the river marked fish, saury, has been reproduced. Liaoning Provincial Government designated the mainstream of Liaohe as conservation area and established a conservation bureau. This is the first administration to be set up in China carrying out integrated basin management. This has provided institutional guarantees for implementation of multi-objective integration to protect the mother river of Liaoning people. The eco-treatment technology and practice of Liaohe Conservation Area were introduced. It has great significance on implementing the state strategy of “construction of ecological civilization”, accomplishing coordinated growth between economy and environment, and realizing harmony between people and nature.
The total contents and pollution status of heavy metals (Fe, Mn, Cu, Zn, Pb, Cd, As and Sb) were investigated in 29 soil samples collected from antimony mine area in Xikuangshan, Lengshuijiang City, Hunan Province. The simple bioaccessibility extraction test (SBET) was used to evaluate the bioaccessibility of heavy metals in soils. In addition, the human health risk assessment of the oral ingestion soil for adults was carried out based on the human health risk model. The results showed that As and Sb are the main pollution elements in the soils, and they have high homology and are easily affected by human activities. Bioaccessibility of soil heavy metals covered a wide range, the rate of bioaccessibility of heavy metals decreased in the order of Mn(36.7%) > Cd(30.7%) > Pb(24.4%)>Zn(23.1%) > Cu(12.0%) > As(5.89%) > Fe(3.88%) > Sb(2.13%), indicating that most of the heavy metals through oral ingestion could not be adsorbed by human body. The results based on total metal contents might overestimate the actual human health risks. After adjustment by bioaccessibility, the health risk values were greatly reduced, the average hazard index (HI) and total carcinogenic risk (TCR) values were reduced by 97% and 92%, respectively. Sb and As are two predominant contributors to human health risks. In addition, the hazard index values of some samples in tailing dam area were still higher than the risk threshold value after adjustment by bioaccessibility and deserved special attention.
Sponsored by Chinese Research Academy of Environmental Sciences
