Many minerals in nature have self-purification capacity to hold and stabilize deleterious contaminants into their lattice structures,which can be used for treatment of heavy metals-bearing contaminants. Hydrotalcite L...Many minerals in nature have self-purification capacity to hold and stabilize deleterious contaminants into their lattice structures,which can be used for treatment of heavy metals-bearing contaminants. Hydrotalcite Layer Double Hydroxide (LDH),tobermorite Calcium Silicate Hydrate (CSH) and apatite are ubiquitous minerals in nature,having higher geochemical stability and potential for binding and stabilizing heavy metals. Based on the elucidation of crystal structure property and self-purification principles of the three minerals above,this article discussed how to design the self-purification system of heavy metal-bearing contaminants.展开更多
Dried ground leaves of Psidium guajava L. (guava) were extracted by water and aqueous ethyl alcohol 50% (1:10) ratio, and the total phenolic content in the extracts was determined spectrophotometrically according to ...Dried ground leaves of Psidium guajava L. (guava) were extracted by water and aqueous ethyl alcohol 50% (1:10) ratio, and the total phenolic content in the extracts was determined spectrophotometrically according to Folin- Ciocalteu’s phenol method and calculated as gallic acid equivalent (GAE). Remarkably high total phenolic content 575.3 ±15.5 and 511.6±6.2 mg of GAE/g of dried weight material (for ethanol guava leaf extracts and water guava leaf extracts, respectively) were obtained. The antioxidant activity of lyophilized extracts was determined at ambient temperature by means of a 2,2-diphenyl-1-picrylhydryzyl (DPPH˙) colorimetry with detection scheme at 515 nm. The activity was evalu- ated by the decrease in absorbance as the result of DPPH˙ color change from purple to yellow. The higher the sample concentration used, the stronger was the free radical-scavenging effect. The results obtained showed that ascorbic acid was a substantially more powerful antioxidant than the extracts from guava leaf. On the other hand, the commercial guava leaf extracts and ethanol guava leaf extracts showed almost the same antioxidant power whereas water guava leaf extracts showed lower antioxidant activity. The parameter EC50 and the time needed to reach the steady state to EC50 concentration ( TEC50 ) affected the antiradical capacity of the sample. The antioxidant efficiency (AE) has been shown to be a more ade- quate parameter for selecting antioxidants than the widely used EC50. This study revealed that guava leaf extracts comprise effective potential source of natural antioxidants.展开更多
The method has been established to calculate the environmental capacity (ECO), surplus environment capacity (SECO) of water with respect to marine petroleum hydrocarbons associated with oil (PHAOs) and the self-purifi...The method has been established to calculate the environmental capacity (ECO), surplus environment capacity (SECO) of water with respect to marine petroleum hydrocarbons associated with oil (PHAOs) and the self-purification capacity (SPCO) of main self-purification process to PHAOs in the Jiaozhou Bay, China, according to the dynamic model for distribution of marine PHAOs among multiphase environments. The variation of concentration of PHAOs in the Jiaozhou Bay is well simulated by the dynamic model. Based on the model, the ECo, SECo of water with respect to PHAOs in the Jiaozhou Bay were calculated during the last 10 years under the first-class and second-class quality standard requirement, according to SPCO of main self-purification process to PHAOs. The results show that about 200 tons of PHAOs could be discharged into the Jiaozhou Bay for maintaining the first class seawater quality standard, and about 600 tons of PHAOs for the second class seawater quality standard later.展开更多
Twenty-one typical coupled large samples were chosen from areas within and surrounding nature reserves on the Tibetan Plateau using the large sample comparison method(LSCM).To evaluate the effectiveness of the nature ...Twenty-one typical coupled large samples were chosen from areas within and surrounding nature reserves on the Tibetan Plateau using the large sample comparison method(LSCM).To evaluate the effectiveness of the nature reserves in protecting the ecological environment,the alpine grassland net primary production(NPP) of these coupled samples were compared and the differences between them before and after their establishment as protected areas were analyzed.The results showed that:(1) With respect to the alpine grassland NPP,the ecological and environmental conditions of most nature reserves were more fragile than those of the surrounding areas and also lower than the average values for the Tibetan Plateau.(2) Of the 11 typical nature reserves selected,the positive trend in the NPP for Manzetang was the most significant,whereas there was no obvious trend in Taxkorgan.With the exception of Selincuo,the annual NPP growth rate in the nature reserves covered by alpine meadow and wetland was higher than that in nature reserves consisting of alpine steppe and alpine desert.(3) There were notable findings in 21 typical coupled samples:(a) After the establishment of the nature reserves,the annual rate of increase in the NPP in 76% of samples inside nature reserves and 82% of samples inside national nature reserves was higher than that of the corresponding samples outside nature reserves.(b) The effectiveness of ecological protection of the Mid-Kunlun,Changshagongma,Zoige and Selincuo(Selin Co) nature reserves was significant; the effectiveness of protection was relatively sig-nificant in most parts of the Sanjiangyuan and Qiangtang nature reserves,whereas in south-east Manzetang and north Taxkorgan the protection effectiveness was not obvious.(c) The ecological protection effectiveness was significant in nature reserves consisting of alpine meadow,but was weak in nature reserves covered by alpine steppe.This study also shows that the advantage of large sample comparison method in evaluating regional ecology change.Careful design of the samples used,to ensure comparability between the samples,is crucial to the success of this LSCM.展开更多
文摘Many minerals in nature have self-purification capacity to hold and stabilize deleterious contaminants into their lattice structures,which can be used for treatment of heavy metals-bearing contaminants. Hydrotalcite Layer Double Hydroxide (LDH),tobermorite Calcium Silicate Hydrate (CSH) and apatite are ubiquitous minerals in nature,having higher geochemical stability and potential for binding and stabilizing heavy metals. Based on the elucidation of crystal structure property and self-purification principles of the three minerals above,this article discussed how to design the self-purification system of heavy metal-bearing contaminants.
文摘Dried ground leaves of Psidium guajava L. (guava) were extracted by water and aqueous ethyl alcohol 50% (1:10) ratio, and the total phenolic content in the extracts was determined spectrophotometrically according to Folin- Ciocalteu’s phenol method and calculated as gallic acid equivalent (GAE). Remarkably high total phenolic content 575.3 ±15.5 and 511.6±6.2 mg of GAE/g of dried weight material (for ethanol guava leaf extracts and water guava leaf extracts, respectively) were obtained. The antioxidant activity of lyophilized extracts was determined at ambient temperature by means of a 2,2-diphenyl-1-picrylhydryzyl (DPPH˙) colorimetry with detection scheme at 515 nm. The activity was evalu- ated by the decrease in absorbance as the result of DPPH˙ color change from purple to yellow. The higher the sample concentration used, the stronger was the free radical-scavenging effect. The results obtained showed that ascorbic acid was a substantially more powerful antioxidant than the extracts from guava leaf. On the other hand, the commercial guava leaf extracts and ethanol guava leaf extracts showed almost the same antioxidant power whereas water guava leaf extracts showed lower antioxidant activity. The parameter EC50 and the time needed to reach the steady state to EC50 concentration ( TEC50 ) affected the antiradical capacity of the sample. The antioxidant efficiency (AE) has been shown to be a more ade- quate parameter for selecting antioxidants than the widely used EC50. This study revealed that guava leaf extracts comprise effective potential source of natural antioxidants.
基金Supported bythe National Natural Science Foundation of China projects ( NSFC-40136020 NSFC-40376033)the National +1 种基金Basic Research Priorities Programme (2001CB409703)the Key Project of Chinese Ministry of Education (No.01110)Shandong Nature Science
文摘The method has been established to calculate the environmental capacity (ECO), surplus environment capacity (SECO) of water with respect to marine petroleum hydrocarbons associated with oil (PHAOs) and the self-purification capacity (SPCO) of main self-purification process to PHAOs in the Jiaozhou Bay, China, according to the dynamic model for distribution of marine PHAOs among multiphase environments. The variation of concentration of PHAOs in the Jiaozhou Bay is well simulated by the dynamic model. Based on the model, the ECo, SECo of water with respect to PHAOs in the Jiaozhou Bay were calculated during the last 10 years under the first-class and second-class quality standard requirement, according to SPCO of main self-purification process to PHAOs. The results show that about 200 tons of PHAOs could be discharged into the Jiaozhou Bay for maintaining the first class seawater quality standard, and about 600 tons of PHAOs for the second class seawater quality standard later.
基金The Strategic Priority Research Program of the Chinese Academy of Sciences,No.XDB03030500National Key Technology Research and Development Program,No.2013BAC04B02+1 种基金Key Foundation Project of Basic Work of the Ministry of Science and Technology of China,No.2012FY111400National Natural Science Foundation of China,No.41171080,No.41201095
文摘Twenty-one typical coupled large samples were chosen from areas within and surrounding nature reserves on the Tibetan Plateau using the large sample comparison method(LSCM).To evaluate the effectiveness of the nature reserves in protecting the ecological environment,the alpine grassland net primary production(NPP) of these coupled samples were compared and the differences between them before and after their establishment as protected areas were analyzed.The results showed that:(1) With respect to the alpine grassland NPP,the ecological and environmental conditions of most nature reserves were more fragile than those of the surrounding areas and also lower than the average values for the Tibetan Plateau.(2) Of the 11 typical nature reserves selected,the positive trend in the NPP for Manzetang was the most significant,whereas there was no obvious trend in Taxkorgan.With the exception of Selincuo,the annual NPP growth rate in the nature reserves covered by alpine meadow and wetland was higher than that in nature reserves consisting of alpine steppe and alpine desert.(3) There were notable findings in 21 typical coupled samples:(a) After the establishment of the nature reserves,the annual rate of increase in the NPP in 76% of samples inside nature reserves and 82% of samples inside national nature reserves was higher than that of the corresponding samples outside nature reserves.(b) The effectiveness of ecological protection of the Mid-Kunlun,Changshagongma,Zoige and Selincuo(Selin Co) nature reserves was significant; the effectiveness of protection was relatively sig-nificant in most parts of the Sanjiangyuan and Qiangtang nature reserves,whereas in south-east Manzetang and north Taxkorgan the protection effectiveness was not obvious.(c) The ecological protection effectiveness was significant in nature reserves consisting of alpine meadow,but was weak in nature reserves covered by alpine steppe.This study also shows that the advantage of large sample comparison method in evaluating regional ecology change.Careful design of the samples used,to ensure comparability between the samples,is crucial to the success of this LSCM.
