Effects of dissolved organic matter (DOM) on adsorption and desorption of Hg were investigated in two kinds of soils, Xanthi-Udic Ferralosols (XUF) and Typic Purpli-Udic Cambosols (TPUC). The DOM was obtained from hum...Effects of dissolved organic matter (DOM) on adsorption and desorption of Hg were investigated in two kinds of soils, Xanthi-Udic Ferralosols (XUF) and Typic Purpli-Udic Cambosols (TPUC). The DOM was obtained from humus soil (DOMH), rice straw (DOMR), and pig manure (DOMP). The presence of DOM obviously reduced Hg maximum adsorption capacity with up to 40% decreases over the control, being an order of DOMH (250.00 mg/kg)< DOMR (303.03 mg/kg) < DOMP (322.58 mg/kg) < CK (control 416.67 mg/kg) for the...展开更多
An investigation was conducted on the effect of organic matter （OM） and pH on mercury （Hg） release from soils. Hg release flux was measured using the dynamic flux chamber （DFC） combined with the Lumex multifunct...An investigation was conducted on the effect of organic matter （OM） and pH on mercury （Hg） release from soils. Hg release flux was measured using the dynamic flux chamber （DFC） combined with the Lumex multifunctional mercury analyzer in both laboratory experiment and field monitoring. The results showed that Hg emission from the OM-added soils was apparently low because of the high affinity of OM to Hg, resulting in the reverse order as the amount of OM addition. Meanwhile, Hg release flux from different pH value soils exhibited the same trend for both Hg^2＋ and Hg2^2＋ treatment, increasing the Hg flux with pH value of soils increasing. The trend of Hg release in the pH dependence experiment has been well in agreement with that from the field test. In addition, Hg release seemed to be related to its species in the soil, the flux from Hg^2＋-added soil was obviously higher than that of Hg2^2＋-added soil by the laboratory experiment.展开更多
As a result of intensifying human activities around the Changshou Reservoir, water environmental quality has declined over the years. Water quality had been monitored from 1999 to 2002. The result indicated that the c...As a result of intensifying human activities around the Changshou Reservoir, water environmental quality has declined over the years. Water quality had been monitored from 1999 to 2002. The result indicated that the concentrations of total nitrogen (TN) and total phosphorus (TP) are high. The concentrations of phosphorus range from {0.037} mg/L to {0.444} mg/L, exceeding the critical value ({0.02} mg/L) for eutrophication. The concentrations of total nitrogen and chlorophyll a range from {0.70} mg/L to {4.18} mg/L and from {1.10} mg/m3 to {61.2} mg/m3, respectively. The eutrophication status of the water body was assessed using the method of integrated nutrition state index, which revealed that all sampling sites were eutrophicated from the year of 2001. About {69.6%} of the annual total nitrogen input and 26% of the annual total phosphorus input originated from the upstreams. The contributions of nitrogen and phosphorus from precipitation to the water body are very small ({0.9%} and {0.3%}, respectively) owing to their low contents ({1.21} mg/L and {0.029} mg/L, respectively). Runoff is the secondarily important input source, which accounts for {19.0%} of the total N input and {47.0%} of the total P input, respectively. Attention should be paid to the aquaculture inputs, whose contributions account for {10.5%} of the total N and {26.6%} of the total phosphorus to the water body, respectively. Nutrient loads are estimated to be 118 gNm{-2}·a{-1} and 8 gPm{-2}·a{-1}. About {69.4%} of nitrogen and {79.7%} of phosphorus input into the reservoir were retained in 2002.展开更多
基金the National Natural Sci-ence Foundation of China (No. 40673063, 40573065)
文摘Effects of dissolved organic matter (DOM) on adsorption and desorption of Hg were investigated in two kinds of soils, Xanthi-Udic Ferralosols (XUF) and Typic Purpli-Udic Cambosols (TPUC). The DOM was obtained from humus soil (DOMH), rice straw (DOMR), and pig manure (DOMP). The presence of DOM obviously reduced Hg maximum adsorption capacity with up to 40% decreases over the control, being an order of DOMH (250.00 mg/kg)< DOMR (303.03 mg/kg) < DOMP (322.58 mg/kg) < CK (control 416.67 mg/kg) for the...
基金Project supported by the National Natural Science Foundation of China(No.405730065,406730063)
文摘An investigation was conducted on the effect of organic matter （OM） and pH on mercury （Hg） release from soils. Hg release flux was measured using the dynamic flux chamber （DFC） combined with the Lumex multifunctional mercury analyzer in both laboratory experiment and field monitoring. The results showed that Hg emission from the OM-added soils was apparently low because of the high affinity of OM to Hg, resulting in the reverse order as the amount of OM addition. Meanwhile, Hg release flux from different pH value soils exhibited the same trend for both Hg^2＋ and Hg2^2＋ treatment, increasing the Hg flux with pH value of soils increasing. The trend of Hg release in the pH dependence experiment has been well in agreement with that from the field test. In addition, Hg release seemed to be related to its species in the soil, the flux from Hg^2＋-added soil was obviously higher than that of Hg2^2＋-added soil by the laboratory experiment.
文摘As a result of intensifying human activities around the Changshou Reservoir, water environmental quality has declined over the years. Water quality had been monitored from 1999 to 2002. The result indicated that the concentrations of total nitrogen (TN) and total phosphorus (TP) are high. The concentrations of phosphorus range from {0.037} mg/L to {0.444} mg/L, exceeding the critical value ({0.02} mg/L) for eutrophication. The concentrations of total nitrogen and chlorophyll a range from {0.70} mg/L to {4.18} mg/L and from {1.10} mg/m3 to {61.2} mg/m3, respectively. The eutrophication status of the water body was assessed using the method of integrated nutrition state index, which revealed that all sampling sites were eutrophicated from the year of 2001. About {69.6%} of the annual total nitrogen input and 26% of the annual total phosphorus input originated from the upstreams. The contributions of nitrogen and phosphorus from precipitation to the water body are very small ({0.9%} and {0.3%}, respectively) owing to their low contents ({1.21} mg/L and {0.029} mg/L, respectively). Runoff is the secondarily important input source, which accounts for {19.0%} of the total N input and {47.0%} of the total P input, respectively. Attention should be paid to the aquaculture inputs, whose contributions account for {10.5%} of the total N and {26.6%} of the total phosphorus to the water body, respectively. Nutrient loads are estimated to be 118 gNm{-2}·a{-1} and 8 gPm{-2}·a{-1}. About {69.4%} of nitrogen and {79.7%} of phosphorus input into the reservoir were retained in 2002.
