5 different forests of Pinus massoniana, Schima superba, Liquidambar formosana, P. massoniana × S. superba, P. massoniana × L. formosana as the research object were set up to study the Cr, Cu and Zn content ...5 different forests of Pinus massoniana, Schima superba, Liquidambar formosana, P. massoniana × S. superba, P. massoniana × L. formosana as the research object were set up to study the Cr, Cu and Zn content of degraded red soil region in subtropics. The soil heavy metal pollution degree was evaluated by national environmental quality standard (II class). The results showed that three soil metals of P. massoniana × S. superba were the highest, and the soil metals enrichment ability was strong. The order of single factor pollution index of metal elements was Cu (1.38) > Cr (0.81) > Zn (0.42), and moderately pollution, pollution warning and no pollution, respectively. There was no significant correlation between three soil heavy metals and soil total carbon (TC), total nitrogen (TN) and total phosphorus (TP). These results suggested that the accumulation of heavy metal elements was not derived from the parent material of soil. There was a significant positive correlation between the three metal elements which indicated that the sources of the three elements were similar. The structural equation model showed that the direct and indirect effects among the influencing factors ultimately affected the activity of heavy metals by cascade effects.展开更多
[Objectives]This study was conducted to further enrich the research on saline-alkali land improvement,and explore the effects of biological bacterial fertilizers containing Bacillus subtilis and Bacillus velezensis HM...[Objectives]This study was conducted to further enrich the research on saline-alkali land improvement,and explore the effects of biological bacterial fertilizers containing Bacillus subtilis and Bacillus velezensis HM-3 in saline-alkali land improvement and crop growth promotion.[Methods]Wheat was planted in saline-alkali land in Huanghua City,Hebei Province,and a mixed application experiment was carried out using biological agents from Hemiao Biotechnology Co.,Ltd.[Results]Compared with the field of control check(CK),water-soluble salts and pH value in the experimental fields decreased,and living bacteria count in the soil increased.Meanwhile,the economic characters of wheat in the experimental fields showed excellent performance,with yields increasing by 39.09%and 27.49%compared with the CK.It could be seen that the application of biological bacterial fertilizers achieved obvious effects of improving saline-alkali soil and increasing wheat yield.[Conclusions]In this study,the effects of biological bacterial fertilizers on saline-alkali land and wheat growth characters were clarified,providing some technical support and theoretical guidance for wheat planting in Huanghua saline-alkali land.展开更多
Diet is one of the main pathways for heavy metals to enter the human body,so studying the content of heavy metals in agricultural products and evaluating them is of great significance.When farmland soil is contaminate...Diet is one of the main pathways for heavy metals to enter the human body,so studying the content of heavy metals in agricultural products and evaluating them is of great significance.When farmland soil is contaminated with heavy metals,the heavy metals accumulated in the soil will be absorbed by the roots of rice plants growing on it,and will migrate and transform between different tissues and organs of rice plants.There is a significant correlation between heavy metal pollution in soil and the content of heavy metals in rice.The migration and enrichment of heavy metals in the agricultural soil rice system is a complex process that is influenced by many factors,such as the physical and chemical properties of the soil,the content and occurrence forms of heavy metals in the soil,and the physiological characteristics of rice plants.In actual field environments,these influencing factors have significant spatial differences and are relatively complex.Therefore,it is necessary to conduct practical analysis of the various influencing factors in actual field environments.Based on actual data analysis,studying the heavy metal content in rice and the characteristics of heavy metal accumulation and migration in rice plants is of great significance for improving the food safety of rice.展开更多
The continuous enrichment of heavy metals in soils has caused potential harm to groundwater.Quantitative methods to evaluate the harm of heavy metals in soil to groundwater are lacked in previous studies.Based on the ...The continuous enrichment of heavy metals in soils has caused potential harm to groundwater.Quantitative methods to evaluate the harm of heavy metals in soil to groundwater are lacked in previous studies.Based on the theory of groundwater circulation and solid-liquid equilibrium,a simple and easy-touse flux model of soil heavy metals migrating to groundwater is constructed.Based on groundwater environmental capacity,an innovative method for evaluating the harm of heavy metals in soil to groundwater is proposed,which has been applied in Hunchun Basin,Jilin Province,China.The results show that the fluxes of soil heavy metals into groundwater in the study area are Zn,Cu,As,Pb,Cd,Ni,and Hg in descending order.The content of heavy metals in groundwater(As,Hg,Cu,Pb,Zn,Ni,and Cd)in most areas has not risen to the threshold of environmental capacity within 10 years.The harm levels of soil heavy metals to groundwater in the most townships soils are at the moderate level or below.This evaluation method can quantify the flux of soil heavy metals into groundwater simply and quickly,determine the residual capacity of groundwater to heavy metals,evaluate the harm level of soil heavy metals to groundwater,provide support for relevant departments to carry out environmental protection of soil and groundwater,and provide a reference to carry out similar studies for related scholars.展开更多
The burial of waste in developing countries, which is often carried out without respect for environmental standards, constitutes a risk of contamination of soils and even groundwater given the toxic elements they cont...The burial of waste in developing countries, which is often carried out without respect for environmental standards, constitutes a risk of contamination of soils and even groundwater given the toxic elements they contain. The objective of this work is to carry out a study of the retention of heavy metals through the contribution of cattle manure to soil samples from the final Agoè Nyivé landfill in Lomé, Togo. Soil samples from the final landfill were taken from the surface and depth at several locations to form a composite sample. The amendment of the composite sample was carried out with bovine manure on the mock-up in the Laboratory for six months. The determination of the total contents of heavy metals by the atomic absorption spectrophotometer (SAA) on the composite sample showed high contents exceeding the thresholds recommended by the AFNOR NF U 44-041 standard. Sequential extraction on these composite samples showed that the mobile portions of lead, cadmium, copper and zinc are respectively estimated at 78.06%, 50%, 28.89% and 91.59%. The bovine manure used to amend the landfill samples presents physicochemical parameters that can contribute to rendering heavy metals immobile in the soil matrix under natural conditions. The addition of manure initially made it possible to increase the values of pH, electrical conductivity, cation exchange capacity and organic matter, which promote the retention of heavy metals. Secondly, the addition of manure made it possible to reduce the mobile portion of the heavy metals studied;from 78.06% to 14.39% for lead, from 50% to 11.52% for cadmium, from 28.89% to almost 0% for copper and from 91.15% to 80.58% for zinc. The use of cattle manure as an amendment on the composite sample was decisive in reducing the mobility of heavy metals in the polluted soils of the final landfill.展开更多
The objective of this study was to establish a baseline for future studies that aim to determine possible contamination from human, agricultural and industrial activities. As well as the determination of the indices o...The objective of this study was to establish a baseline for future studies that aim to determine possible contamination from human, agricultural and industrial activities. As well as the determination of the indices of environmental or geological contamination and enrichment factors of heavy metals Cr, Ni, Cu, Zn, As, Cd, Hg and Pb in agricultural soils of Constanza, Jarabacoa, Rancho Arriba and San José de Ocoa (SJO), municipalities located in the valleys of the Central mountain range of the Dominican Republic. The determination of the concentrations of heavy metals was carried out using the X-ray Fluorescence technique. Just like in Azua, San Juan de la Maguana (SJM) y Barahona in the southwest. Producer municipalities of vegetables, rice, beans, corn, melon, watermelon, tomato, banana, avocado, sugar cane and fodder for cattle. The concentration of 160 mg·kg<sup>-1</sup> Probable Effect Level (PEL) of Cr according to the SQuiRTs table (USEPA-NOAA) for agricultural soils, were exceeded in 50% of the samples in SJM, SJO, Jarabacoa and Constanza;in Barahona and Azua by 20%. The PEL of 42.8 mg·kg-1</sup><sup></sup> of the Ni was higher in more than 50% of the samples from SJM, Azua, Barahona and Jarabacoa;in SJO and Constanza at 35%. In the case of Cu with a PEL of 108 mg·kg-1</sup><sup></sup> in SJO and Constanza, 5% of the samples exceeded its, in the other areas the concentrations were lower. Zn, As and Pb did not manage to exceed their respective PEL.展开更多
Heavy metals have been viewed as hazardous environmental pollutants, and anthropogenic activities due to their high toxicity and persistent nature in the environment. Anthropogenic activities such as artisanal mining,...Heavy metals have been viewed as hazardous environmental pollutants, and anthropogenic activities due to their high toxicity and persistent nature in the environment. Anthropogenic activities such as artisanal mining, industrial activities, improper usage of fertilizers and pesticides, and indiscriminate open waste disposal bring about an increase in the presence of heavy metals in the environment. In the Keffi Metropolis, different elements lead to land contamination which debilitates soil quality, plant survival, human well-being, and the environment as a result of extensive dispersion or quantity of heavy metals in the soil and water. In recent years, biochar has emerged as a promising soil amendment for mitigating heavy metal pollution due to its unique physicochemical properties. This paper provides the effects of softwood pellet biochar on the retention of heavy metals in contaminated soils. A microcosm experiment was carried out to investigate the effects of biochar on the retention of heavy metals in contaminated soils. This research aimed to give an overview of the effects of softwood biochar at different temperatures (550˚C and 700˚C) on the retention of heavy metals and metalloids released from the soil during water inundation. The results show that the addition of organic matter (grass chippings) minimizes heavy metal mobilization. Also, biochar at high temperatures is more effective than those at low temperatures. The expected outcome of the research analysis includes providing insights into the role of biochar in retaining heavy metal contamination and further understanding the use of biochar as a sorbent for the management of contaminated soil.展开更多
This study studied the characteristics and source apportionment of heavy metal pollution in the agricultural soil surrounding a gangue coal heap in Chongqing,China by using absolute principal component scores-multiple...This study studied the characteristics and source apportionment of heavy metal pollution in the agricultural soil surrounding a gangue coal heap in Chongqing,China by using absolute principal component scores-multiple linear regression(APCSMLR)model and positive matrix factorization(PMF)model.The applicability of the models was compared in the assessment of source apportionment.The results showed that the average contents of Cd,Hg,As,Pb,Cr,Cu,Ni,and Zn in the surface soil were 0.46,0.14,9.66,31.2,127,95.6,76.0,and 158 mg/kg,respectively.Combined with the spatial distribution and correlation analyses,the results of source apportionment were consistent for both the APCSMLR and PMF models.Cd,Hg,As,and Pb were mainly affected by the gangue heap accumulation,with respective contributions of 74.6%,79.4%,69.1%,and 67.2%based on the APCS-MLR model and respective contributions of 69.7%,60.7%,57.4%,and 41.9%based on the PMF model.Ni and Zn were mainly affected by industrial and agricultural activities,while Cr and Cu were mainly affected by natural factors.The results of the source apportionment were approximately consistent between the APCS-MLR and PMF models.The combined application of the two receptor models can make the results of source apportionment more comprehensive,accurate,and reliable.展开更多
The Luanchuan molybdenum polymetallic mine concentration area is rich in mineral resources and has a long history of mining.The environmental impact of long-term mining activities cannot be ignored.It is of great sign...The Luanchuan molybdenum polymetallic mine concentration area is rich in mineral resources and has a long history of mining.The environmental impact of long-term mining activities cannot be ignored.It is of great significance to study the ecological risk and the accumulation trends of heavy metals in the soil of mining areas for scientific prevention and control of heavy metal pollution.Taking the Taowanbeigou River Basin in the mine concentration area as the research object,the ecological pollution risk and cumulative effect of heavy metals in the soil of the basin were studied by using the comprehensive pollution index method,potential ecological risk assessment method and geoaccumulation index method.On this basis,the cumulative exceeding years of specific heavy metals were predicted by using the early warning model.The comprehensive potential ecological risk of heavy metals in the soil near the Luanchuan mine concentration area is moderate,and the single element Cd is the main ecological risk factor,with a contribution rate of 53.6%.The overall cumulative degrees of Cu and Pb in the soil are“none-moderate”,Zn and Cd are moderate,Mo has reached an extremely strong cumulative level,Hg,As and Cr risks are not obvious,and the overall cumulative risks order is Mo>Cd>Zn>Cu>Pb>Hg.According to the current accumulation rate and taking the risk screening values for soil contamination of agricultural land as the reference standard,the locations over standard rates of Cu,Zn and Cd will exceed 78%in 90years,and the over standard rate of Pb will reach approximately 57%in 200 years.The cumulative exceeding standard periods of As,Cr and Hg are generally long,which basically indicates that these elements do not pose a significant potential threat to the ecological environment.Mining activities will accelerate the accumulation of heavy metals in soil.With the continuous development of mining activities,the potential pollution risk of heavy metals in the soil of mining areas will also increase.展开更多
To evaluate soil environmental quality of introduced new crops and other traditional crops,and to understand the importance of response of soil microbial community to heavy metal stress,rhizosphere soil samples of dif...To evaluate soil environmental quality of introduced new crops and other traditional crops,and to understand the importance of response of soil microbial community to heavy metal stress,rhizosphere soil samples of different land use types(Sphagnum farming,rice field,grassland and bare land) in Dading Village,Duyun City,Guizhou Province of China were selected as research objects.The differences of soil chemical properties,heavy metal concentration and microbial community among different land use types were compared.The abundance and structural diversity of microbial communities in soil samples were analyzed by 16S rDNA sequencing,the relationship between soil pollution characteristics and microbial community in farmland was studied.The results showed that the different land use types planting different agricultural products under the same growing environment were subject to different heavy metal pollution.Soil chemical properties and heavy metals had significant effects on the soil microbial community.Proteobacteria,Actinobacteriota and Acidobacteriota were the most dominant groups of bacteria.The soil microorganisms responded more actively to the variability of pH,SOM and AK contents,although the variability was not high.With the increase of pH value,the abundance of the dominant species Proteobacteria also increased.Verrucomicrobiota had a better tolerance to the heavy metal Hg.Verrucomicrobiota and Firmicutes had strong resistance to the heavy metal Cd.These results deepen our understanding of the changes and aggregation of microorganisms under different land use patterns in heavy-metal contaminated farmland soils.展开更多
A pot experiment was conducted to research the effect of biochar and wood vinegar on labile phosphorus fractions in saline-alkali soil.There were eight treatments,including CK(0 kg•hm-2 biochar+0 kg•hm-2 wood vinegar)...A pot experiment was conducted to research the effect of biochar and wood vinegar on labile phosphorus fractions in saline-alkali soil.There were eight treatments,including CK(0 kg•hm-2 biochar+0 kg•hm-2 wood vinegar),C1(0.6 t•hm-2 biochar),C2(0.6 t•hm-2 wood vinegar),C3(1.2 t•hm-2 wood vinegar),C4(1.8 t•hm-2 wood vinegar),C5(0.6 t•hm-2 biochar+0.6 t•hm-2 wood vinegar),C6(0.6 t•hm-2 biochar+1.2 t•hm-2 wood vinegar),and C7(0.6 t•hm-2 biochar+1.8 t•hm-2 wood vinegar).The results showed that biochar without wood vinegar and the co-application of biochar and wood vinegar significantly increased soil total phosphorus content.Meanwhile,compared with CK,all of treatments increased resin phosphorus and sodium bicarbonate-extracted inorganic phosphorus(NaHCO3-Pi)contents in saline-alkali soil.Especially,the contents of resin phosphorus and NaHCO3-Pi under C5,C6,and C7 treatments were higher than those of C2,C3,and C4 treatments,respectively,indicating that the increases of labile phosphorus contents under the co-application of biochar and wood vinegar were better than those of the alone application of biochar and wood vinegar.Each treatment increased the proportion of labile phosphorus pool in saline-alkali soil and the proportion of labile phosphorus pool increased with the increase of the amount of wood vinegar.In addition,the application of biochar and wood vinegar increased the 100-grain weight of rice,and C6 treatment had the best effect,increasing the 100-grain weight by 134.35%.Therefore,the application of biochar and wood vinegar in saline-alkali soil could improve the soil phosphorus availability,increase the weight of rice grains,thereby realizing the resource utilization of agricultural waste and the sustainable development of agriculture.展开更多
Heavy metals in agricultural soil pose human health risks through food consumption. In a novel study for Trinidad, concentration and pollution index levels of heavy metals were assessed from 18 agricultural farms usin...Heavy metals in agricultural soil pose human health risks through food consumption. In a novel study for Trinidad, concentration and pollution index levels of heavy metals were assessed from 18 agricultural farms using the X-Ray fluorescence technique, then to evaluate the Geo-accumulation and Nemerow’s Integrated Pollution indexes. Toxic elements Pb and As were present but soil quality due to anthropogenic input was found as unpolluted. Overall heavy metal pollution was classified at a precautionary level for 33% of farms, slightly polluted for 61% and moderately polluted for 6% of the farms assessed, thus, regular monitoring and mitigation measures are important for food safety and human health in Trinidad.展开更多
This study focuses on the use of heavy fuel oil in construction in Burkina Faso.Mixed with silty and/or clay soil,it is used as a coating to reinforce the walls of raw soil constructions which are very sensitive to wa...This study focuses on the use of heavy fuel oil in construction in Burkina Faso.Mixed with silty and/or clay soil,it is used as a coating to reinforce the walls of raw soil constructions which are very sensitive to water.The interest of this paper is to shed light on the thermomechanical and above all water effects of heavy fuel oil on a sample of silty clayey soil.To achieve this,we used heavy fuel oil added in different proportions to silty clayey soil,to make sample of bricks on which tests were carried out.At the end of the experimental tests carried out on materials made(bricks)with our soil sample,it appears that heavy fuel oil moderately reduces the mechanical resistance of bricks and slightly increases thermal diffusion through them.On the contrary,we note a very good water resistance of the bricks thanks to the heavy fuel oil,in particular their water absorption by capillarity.This confirms that the mixture of heavy fuel oil and a silty-clayey soil used as a coating makes it possible to prevent the infiltration of water into the walls of raw soil constructions.However,its use as a construction material does not guarantee very good mechanical resistance,and slightly increases thermal diffusion.展开更多
Clarifying the soil nutrient dynamics caused by forest type variations in the coastal region helps scientifically to apply fertilizer to forest plantations and enhance the carbon(C)sink capacity.Pure forests of Ligust...Clarifying the soil nutrient dynamics caused by forest type variations in the coastal region helps scientifically to apply fertilizer to forest plantations and enhance the carbon(C)sink capacity.Pure forests of Ligustrum and Metasequoia,as well as their mixed forests,in a coastal region of China were investigated by collecting 0-20 and 20-40 cm soil samples and analyzing their differences in bulk density,water content,pH,soil organic matter(SOM),ammonium(NH_(4)^(+)-N),nitrate(NO_(3)^(-)-N)and total nitrogen(TN),available phosphorus(AP)and potassium(AK),microbial biomass C(MBC)and N(MBN),and enzyme activity.The results demonstrated that different forest types had no significant(p≥0.05)effect on 0-20 cm soil bulk density,water content,pH,NH_(4)^(+)-N,and SOM.However,the surface soil NO_(3)^(-)-N,TN,AP,and AK contents as well as enzyme activity changed significantly(p<0.05),in which the soil AK content of the ligustrum×metasequoia mixed forest was 47.5%and 65.5%higher than that of the ligustrum and metasequoia pure forest,respectively.The mixed forest soil had the highest MBN content,which was significantly(p<0.05)25.1%higher than that in the pure metasequoia forest.Meanwhile,soil phosphatase activities in ligustrum and metasequoia pure forests were significantly(p<0.05)lower than those in the mixed forests by 17.4%and 43.1%,respectively.However,soil NO_(3)^(-)-N and AP contents in the metasequoia pure forest were significantly(p<0.05)higher than those in the ligustrum pure forest and mixed forests.Soil MBC content and reductase NO_(3)^(-)-N activity were significantly(p<0.05)higher in ligustrum pure forest than in metasequoia pure forest and mixed forests.In addition,the results of two-way ANOVA showed that there were no significant(p≥0.05)differences in nutrient contents(e.g.,NH_(4)^(+)-N,AP,AK,and SOM)in different soil layers(0-20 and 20-40 cm)within the same forest type,except for NO_(3)^(-)-N.However,forest types had a significant(p<0.05)impact on NO_(3)^(-)-N and AP contents in 20-40 cm soil layer.Combining the two factors of forest stand and soil layer,there was a significant(p<0.05)interaction effect for their soil NH_(4)^(+)-N,NO_(3)^(-)-N,AP,and AK contents.In conclusion,significant(p<0.05)differences were observed in nutrient contents in 0-20 cm soil layer from different forest types,with soil fertility indices inmixed forests generally higher than in pure forests.Therefore,establishing mixed forests in coastal saline region is recommended to retain soil fertility and to enhance the C sink capacity of forestry.展开更多
The aim of this study to investigate the physico-chemical properties of soils from Diguel and Koudalwa Tchad,and phytoremediation potentials of acasia and kinkeliba plants in removing Cr and Cu from these soils.Soil w...The aim of this study to investigate the physico-chemical properties of soils from Diguel and Koudalwa Tchad,and phytoremediation potentials of acasia and kinkeliba plants in removing Cr and Cu from these soils.Soil was sampled from the tannery plant in Diguel and agricultural land around crude oil activities in Koudalwa.Soils were characterized by the following properties:pH,(Electrical Conductivity),TDS(Total Dissolved Solids),salinity,bulk density,OM(Organic Matter),nitrate,phosphate,clay,silt,sand,and textural class.The acasia and kinkeliba plants were used to decontaminate Cu and Cr from sample soils for 30 days period.The bulk density of all the soil samples from Kouldawa was higher compared to Diguil,ranging from 1.421 to 1.64 g/cm^(3)compared to 1.21 to 1.51 g/cm^(3)for Diguel.Most of the soils in Kouldawa are mineral soils,while those of Diguel are mostly mineral soil with some organics.Diguel soils are richer in nitrate(577.9 to 2,687.32 mg/kg in Diguel and 33.64 to 197.64 mg/kg in Kouldawa)and phosphate than soils from Kouldawa.Soils from the studied areas are not saline except for a subsurface soil in Diguel(salinity,4.21;EC,4.280 dS/m;TDS,3,040 mg/L).The highest amount of Cr and Cu removed by acasia is 78%and 53.12%compared to 73.8%and 52.21%by kinkeliba.Diguel soil can be very suitable for agriculture and Kouldawa soils for construction.Acasia and kinkeliba can be effectively used to decontaminate the studied soils from heavy metal pollution.展开更多
This study aims to investigate the level of soil pollution and the grade of accumulation of metals and heavy metals by wheat plants from the soil in different parts of the crop: root, stem, leaf, spike and grain. Samp...This study aims to investigate the level of soil pollution and the grade of accumulation of metals and heavy metals by wheat plants from the soil in different parts of the crop: root, stem, leaf, spike and grain. Sampling campaigns took place in February, April and July when wheat plants were at different growth stages. A number of eight soil samples and eight wheat plant samples were collected. The sampled wheat plant was taken at the same time and from the same place as the soil. Concentrations of Al (aluminium), Cr (chromium), Mn (manganese), Fe (iron), Ni (nickel), Co (cobalt), Cu (copper), Zn (zinc), Sr (strontium), Cd (cadmium) and Pb (lead) were determined by inductively coupled plasma mass spectrometry. Bioconcentration and translocation factors were calculated for the samples analysed.展开更多
Through sampling in farmland and analysis in laboratory,the contents and the pollution level of Cr,Cu,As,Pb,Zn in different soils were studied. The comparative result showed that the As in all soil samples are lower t...Through sampling in farmland and analysis in laboratory,the contents and the pollution level of Cr,Cu,As,Pb,Zn in different soils were studied. The comparative result showed that the As in all soil samples are lower than the mean value of Shaanxi and whole nation,the Cr in lower half soil samples are higher than the mean value of Shaanxi and whole nation,the Cu and Zn in majority soil samples are higher than the mean value of Shaanxi and whole nation,and the Pb in all soil samples is higher than the mean value of Shaanxi and whole nation. The single factor pollution index and multi-factor pollution index method were used to evaluate the soil pollution. According to Soil Environmental Quality Standard,the studied soils were at unpolluted degrees,the soils were clear,the quality of soil adapt to the crop growth,and not affect the quality of agricultural product.展开更多
Phytoremediation is an efficient and economic ecological technology. It includes phytostabilization, phytovolatilization, and plant absorption. In the research, status quo and progress of Phytostabilization and plant ...Phytoremediation is an efficient and economic ecological technology. It includes phytostabilization, phytovolatilization, and plant absorption. In the research, status quo and progress of Phytostabilization and plant absorption in soils polluted with heavy metals in metal mines were summarized, including the characteristics and status quo of phytoremediation and selection method of hyperaccumulator. In addition, further research was proposed as well.展开更多
[Objective] The aim was to study on effects of heavy metals and saline-alkali on growth, physiology and biochemistry of Orychophragmus violaceus. [Method] Taken Orychophragmus violaceus as materials, growth, physiolog...[Objective] The aim was to study on effects of heavy metals and saline-alkali on growth, physiology and biochemistry of Orychophragmus violaceus. [Method] Taken Orychophragmus violaceus as materials, growth, physiology and biochemistry were explored under stress of saline-alkali and heavy metals (light, moderate and severe saline-alkali, Pb, Pb + Cd, light saline-alkali + Pb, moderate saline-alkali + Pb, severe saline-alkali + Pb, light saline-alkali + Pb + Cd, moderate saline-alkali + Pb + Cd and severe saline-alkali + Pb + Cd) with control group set. [Result] Light stress of saline-alkali had little effect on membrane permeability, as follows: MDA contents in leaves and root systems declined by 25.6% and 9.0% compared with control group; Pb (500 mg/L) stress promoted synthetization of photosynthetic pigments, as follows: chlorophyll a and b and carotenoid increased by 0.86%, 0.69% and 6.25% than those of control group; combined stresses of Pb and Cd destroyed synthetization of photosynthetic pigments, among which carotenoid was more sensitive; under combined stresses of saline-alkali, Pb and Cd, POD and SOD activities, soluble saccharides and Pro content all increased and activities of POD and SOD in root system were both higher than those in leaves. [Conclusion] Orychophragmus violaceus is with resistance against light combined stresses of saline-alkali and Pb (500 mg/L).展开更多
ObjectiveThis study aimed to investigate the accumulation of heavy metals from organic fertilizer in soil and plant. MethodThree plots were chosen in Shanghai suburb to measure the heavy metal accumulation by monitori...ObjectiveThis study aimed to investigate the accumulation of heavy metals from organic fertilizer in soil and plant. MethodThree plots were chosen in Shanghai suburb to measure the heavy metal accumulation by monitoring their concentrations in soil and plant after organic fertilizer was applied. We also analyzed the correlations of the heavy metals in soil and plants. Single-factor pollution index and Nemerow’s synthetical pollution index were adopted to evaluate the heavy metal contamination in soils. Moreover, how many years before the heavy metal accumulation will exceed the environmental capability if 45 t/hm 2 organic fertilizer is applied every year was also estimated in the present study. ResultThe rules of heavy metals’ accumulation in soil changed with the various soil characters and pH. The average concentrations of Pb, Cd and As in the tested plants exceeded the limits. The average concentration of Cu in the tested soil shared positive correlation with that in the tested plants. The average concentration of Pb in the tested soil was negatively correlated with that in the tested plant while the other heavy metals didn’t show the rule like that. Organic fertilizer application caused no obvious pollution to the soils. Cu would exceed the standard environmental capacity within 15 years if 45 t/hm 2 organic fertilizer is applied every year, while for Hg, it will be 2 000 years. ConclusionWhen the excessive organic fertilizer is put into the land, the heavy metals from organic fertilizer would accumulate in soil and plant. With continued excessive fertilization, the heavy metals especially Cu would exceed the stan- dard environmental capacity. More attention should be paid to the inputting amount of the organic fertilizer.展开更多
文摘5 different forests of Pinus massoniana, Schima superba, Liquidambar formosana, P. massoniana × S. superba, P. massoniana × L. formosana as the research object were set up to study the Cr, Cu and Zn content of degraded red soil region in subtropics. The soil heavy metal pollution degree was evaluated by national environmental quality standard (II class). The results showed that three soil metals of P. massoniana × S. superba were the highest, and the soil metals enrichment ability was strong. The order of single factor pollution index of metal elements was Cu (1.38) > Cr (0.81) > Zn (0.42), and moderately pollution, pollution warning and no pollution, respectively. There was no significant correlation between three soil heavy metals and soil total carbon (TC), total nitrogen (TN) and total phosphorus (TP). These results suggested that the accumulation of heavy metal elements was not derived from the parent material of soil. There was a significant positive correlation between the three metal elements which indicated that the sources of the three elements were similar. The structural equation model showed that the direct and indirect effects among the influencing factors ultimately affected the activity of heavy metals by cascade effects.
基金Supported by Key Research and Development Program of Hebei Province(20322911D,21322903D)Innovation Ability Promotion Program of Hebei Province(20562903D)+1 种基金Technical Innovation Guidance Program of Hebei Province(20822904D)Science and Technology Research and Development Program of Qinhuangdao City(202201B028).
文摘[Objectives]This study was conducted to further enrich the research on saline-alkali land improvement,and explore the effects of biological bacterial fertilizers containing Bacillus subtilis and Bacillus velezensis HM-3 in saline-alkali land improvement and crop growth promotion.[Methods]Wheat was planted in saline-alkali land in Huanghua City,Hebei Province,and a mixed application experiment was carried out using biological agents from Hemiao Biotechnology Co.,Ltd.[Results]Compared with the field of control check(CK),water-soluble salts and pH value in the experimental fields decreased,and living bacteria count in the soil increased.Meanwhile,the economic characters of wheat in the experimental fields showed excellent performance,with yields increasing by 39.09%and 27.49%compared with the CK.It could be seen that the application of biological bacterial fertilizers achieved obvious effects of improving saline-alkali soil and increasing wheat yield.[Conclusions]In this study,the effects of biological bacterial fertilizers on saline-alkali land and wheat growth characters were clarified,providing some technical support and theoretical guidance for wheat planting in Huanghua saline-alkali land.
基金Supported by Natural Science Foundation of Fujian Province(2023J01130334)Natural Science Foundation of Xiamen City(3502Z20227315).
文摘Diet is one of the main pathways for heavy metals to enter the human body,so studying the content of heavy metals in agricultural products and evaluating them is of great significance.When farmland soil is contaminated with heavy metals,the heavy metals accumulated in the soil will be absorbed by the roots of rice plants growing on it,and will migrate and transform between different tissues and organs of rice plants.There is a significant correlation between heavy metal pollution in soil and the content of heavy metals in rice.The migration and enrichment of heavy metals in the agricultural soil rice system is a complex process that is influenced by many factors,such as the physical and chemical properties of the soil,the content and occurrence forms of heavy metals in the soil,and the physiological characteristics of rice plants.In actual field environments,these influencing factors have significant spatial differences and are relatively complex.Therefore,it is necessary to conduct practical analysis of the various influencing factors in actual field environments.Based on actual data analysis,studying the heavy metal content in rice and the characteristics of heavy metal accumulation and migration in rice plants is of great significance for improving the food safety of rice.
基金supported by the project of China Geology Survey(12120115032801,DD20190340)。
文摘The continuous enrichment of heavy metals in soils has caused potential harm to groundwater.Quantitative methods to evaluate the harm of heavy metals in soil to groundwater are lacked in previous studies.Based on the theory of groundwater circulation and solid-liquid equilibrium,a simple and easy-touse flux model of soil heavy metals migrating to groundwater is constructed.Based on groundwater environmental capacity,an innovative method for evaluating the harm of heavy metals in soil to groundwater is proposed,which has been applied in Hunchun Basin,Jilin Province,China.The results show that the fluxes of soil heavy metals into groundwater in the study area are Zn,Cu,As,Pb,Cd,Ni,and Hg in descending order.The content of heavy metals in groundwater(As,Hg,Cu,Pb,Zn,Ni,and Cd)in most areas has not risen to the threshold of environmental capacity within 10 years.The harm levels of soil heavy metals to groundwater in the most townships soils are at the moderate level or below.This evaluation method can quantify the flux of soil heavy metals into groundwater simply and quickly,determine the residual capacity of groundwater to heavy metals,evaluate the harm level of soil heavy metals to groundwater,provide support for relevant departments to carry out environmental protection of soil and groundwater,and provide a reference to carry out similar studies for related scholars.
文摘The burial of waste in developing countries, which is often carried out without respect for environmental standards, constitutes a risk of contamination of soils and even groundwater given the toxic elements they contain. The objective of this work is to carry out a study of the retention of heavy metals through the contribution of cattle manure to soil samples from the final Agoè Nyivé landfill in Lomé, Togo. Soil samples from the final landfill were taken from the surface and depth at several locations to form a composite sample. The amendment of the composite sample was carried out with bovine manure on the mock-up in the Laboratory for six months. The determination of the total contents of heavy metals by the atomic absorption spectrophotometer (SAA) on the composite sample showed high contents exceeding the thresholds recommended by the AFNOR NF U 44-041 standard. Sequential extraction on these composite samples showed that the mobile portions of lead, cadmium, copper and zinc are respectively estimated at 78.06%, 50%, 28.89% and 91.59%. The bovine manure used to amend the landfill samples presents physicochemical parameters that can contribute to rendering heavy metals immobile in the soil matrix under natural conditions. The addition of manure initially made it possible to increase the values of pH, electrical conductivity, cation exchange capacity and organic matter, which promote the retention of heavy metals. Secondly, the addition of manure made it possible to reduce the mobile portion of the heavy metals studied;from 78.06% to 14.39% for lead, from 50% to 11.52% for cadmium, from 28.89% to almost 0% for copper and from 91.15% to 80.58% for zinc. The use of cattle manure as an amendment on the composite sample was decisive in reducing the mobility of heavy metals in the polluted soils of the final landfill.
文摘The objective of this study was to establish a baseline for future studies that aim to determine possible contamination from human, agricultural and industrial activities. As well as the determination of the indices of environmental or geological contamination and enrichment factors of heavy metals Cr, Ni, Cu, Zn, As, Cd, Hg and Pb in agricultural soils of Constanza, Jarabacoa, Rancho Arriba and San José de Ocoa (SJO), municipalities located in the valleys of the Central mountain range of the Dominican Republic. The determination of the concentrations of heavy metals was carried out using the X-ray Fluorescence technique. Just like in Azua, San Juan de la Maguana (SJM) y Barahona in the southwest. Producer municipalities of vegetables, rice, beans, corn, melon, watermelon, tomato, banana, avocado, sugar cane and fodder for cattle. The concentration of 160 mg·kg<sup>-1</sup> Probable Effect Level (PEL) of Cr according to the SQuiRTs table (USEPA-NOAA) for agricultural soils, were exceeded in 50% of the samples in SJM, SJO, Jarabacoa and Constanza;in Barahona and Azua by 20%. The PEL of 42.8 mg·kg-1</sup><sup></sup> of the Ni was higher in more than 50% of the samples from SJM, Azua, Barahona and Jarabacoa;in SJO and Constanza at 35%. In the case of Cu with a PEL of 108 mg·kg-1</sup><sup></sup> in SJO and Constanza, 5% of the samples exceeded its, in the other areas the concentrations were lower. Zn, As and Pb did not manage to exceed their respective PEL.
文摘Heavy metals have been viewed as hazardous environmental pollutants, and anthropogenic activities due to their high toxicity and persistent nature in the environment. Anthropogenic activities such as artisanal mining, industrial activities, improper usage of fertilizers and pesticides, and indiscriminate open waste disposal bring about an increase in the presence of heavy metals in the environment. In the Keffi Metropolis, different elements lead to land contamination which debilitates soil quality, plant survival, human well-being, and the environment as a result of extensive dispersion or quantity of heavy metals in the soil and water. In recent years, biochar has emerged as a promising soil amendment for mitigating heavy metal pollution due to its unique physicochemical properties. This paper provides the effects of softwood pellet biochar on the retention of heavy metals in contaminated soils. A microcosm experiment was carried out to investigate the effects of biochar on the retention of heavy metals in contaminated soils. This research aimed to give an overview of the effects of softwood biochar at different temperatures (550˚C and 700˚C) on the retention of heavy metals and metalloids released from the soil during water inundation. The results show that the addition of organic matter (grass chippings) minimizes heavy metal mobilization. Also, biochar at high temperatures is more effective than those at low temperatures. The expected outcome of the research analysis includes providing insights into the role of biochar in retaining heavy metal contamination and further understanding the use of biochar as a sorbent for the management of contaminated soil.
基金supported by Project of Chongqing Ecology and Environment Bureau(2021111)Project of Chongqing Science and Technology Bureau(cstc2022jxjl0005)。
文摘This study studied the characteristics and source apportionment of heavy metal pollution in the agricultural soil surrounding a gangue coal heap in Chongqing,China by using absolute principal component scores-multiple linear regression(APCSMLR)model and positive matrix factorization(PMF)model.The applicability of the models was compared in the assessment of source apportionment.The results showed that the average contents of Cd,Hg,As,Pb,Cr,Cu,Ni,and Zn in the surface soil were 0.46,0.14,9.66,31.2,127,95.6,76.0,and 158 mg/kg,respectively.Combined with the spatial distribution and correlation analyses,the results of source apportionment were consistent for both the APCSMLR and PMF models.Cd,Hg,As,and Pb were mainly affected by the gangue heap accumulation,with respective contributions of 74.6%,79.4%,69.1%,and 67.2%based on the APCS-MLR model and respective contributions of 69.7%,60.7%,57.4%,and 41.9%based on the PMF model.Ni and Zn were mainly affected by industrial and agricultural activities,while Cr and Cu were mainly affected by natural factors.The results of the source apportionment were approximately consistent between the APCS-MLR and PMF models.The combined application of the two receptor models can make the results of source apportionment more comprehensive,accurate,and reliable.
基金supported by the Science and Technology Research Project to Henan Provincial Department of Natural Resources(Henan Natural Resources Letter[2019]373–10)。
文摘The Luanchuan molybdenum polymetallic mine concentration area is rich in mineral resources and has a long history of mining.The environmental impact of long-term mining activities cannot be ignored.It is of great significance to study the ecological risk and the accumulation trends of heavy metals in the soil of mining areas for scientific prevention and control of heavy metal pollution.Taking the Taowanbeigou River Basin in the mine concentration area as the research object,the ecological pollution risk and cumulative effect of heavy metals in the soil of the basin were studied by using the comprehensive pollution index method,potential ecological risk assessment method and geoaccumulation index method.On this basis,the cumulative exceeding years of specific heavy metals were predicted by using the early warning model.The comprehensive potential ecological risk of heavy metals in the soil near the Luanchuan mine concentration area is moderate,and the single element Cd is the main ecological risk factor,with a contribution rate of 53.6%.The overall cumulative degrees of Cu and Pb in the soil are“none-moderate”,Zn and Cd are moderate,Mo has reached an extremely strong cumulative level,Hg,As and Cr risks are not obvious,and the overall cumulative risks order is Mo>Cd>Zn>Cu>Pb>Hg.According to the current accumulation rate and taking the risk screening values for soil contamination of agricultural land as the reference standard,the locations over standard rates of Cu,Zn and Cd will exceed 78%in 90years,and the over standard rate of Pb will reach approximately 57%in 200 years.The cumulative exceeding standard periods of As,Cr and Hg are generally long,which basically indicates that these elements do not pose a significant potential threat to the ecological environment.Mining activities will accelerate the accumulation of heavy metals in soil.With the continuous development of mining activities,the potential pollution risk of heavy metals in the soil of mining areas will also increase.
基金the National Natural Science Foundation of China (No.31960044)the Department of Science and Technology Foundation of Guizhou Province, China [DSTFGC (2019)] for financial support。
文摘To evaluate soil environmental quality of introduced new crops and other traditional crops,and to understand the importance of response of soil microbial community to heavy metal stress,rhizosphere soil samples of different land use types(Sphagnum farming,rice field,grassland and bare land) in Dading Village,Duyun City,Guizhou Province of China were selected as research objects.The differences of soil chemical properties,heavy metal concentration and microbial community among different land use types were compared.The abundance and structural diversity of microbial communities in soil samples were analyzed by 16S rDNA sequencing,the relationship between soil pollution characteristics and microbial community in farmland was studied.The results showed that the different land use types planting different agricultural products under the same growing environment were subject to different heavy metal pollution.Soil chemical properties and heavy metals had significant effects on the soil microbial community.Proteobacteria,Actinobacteriota and Acidobacteriota were the most dominant groups of bacteria.The soil microorganisms responded more actively to the variability of pH,SOM and AK contents,although the variability was not high.With the increase of pH value,the abundance of the dominant species Proteobacteria also increased.Verrucomicrobiota had a better tolerance to the heavy metal Hg.Verrucomicrobiota and Firmicutes had strong resistance to the heavy metal Cd.These results deepen our understanding of the changes and aggregation of microorganisms under different land use patterns in heavy-metal contaminated farmland soils.
基金Supported by Funding from Harbin Science and Technology Bureau(2017RAXXJ023)。
文摘A pot experiment was conducted to research the effect of biochar and wood vinegar on labile phosphorus fractions in saline-alkali soil.There were eight treatments,including CK(0 kg•hm-2 biochar+0 kg•hm-2 wood vinegar),C1(0.6 t•hm-2 biochar),C2(0.6 t•hm-2 wood vinegar),C3(1.2 t•hm-2 wood vinegar),C4(1.8 t•hm-2 wood vinegar),C5(0.6 t•hm-2 biochar+0.6 t•hm-2 wood vinegar),C6(0.6 t•hm-2 biochar+1.2 t•hm-2 wood vinegar),and C7(0.6 t•hm-2 biochar+1.8 t•hm-2 wood vinegar).The results showed that biochar without wood vinegar and the co-application of biochar and wood vinegar significantly increased soil total phosphorus content.Meanwhile,compared with CK,all of treatments increased resin phosphorus and sodium bicarbonate-extracted inorganic phosphorus(NaHCO3-Pi)contents in saline-alkali soil.Especially,the contents of resin phosphorus and NaHCO3-Pi under C5,C6,and C7 treatments were higher than those of C2,C3,and C4 treatments,respectively,indicating that the increases of labile phosphorus contents under the co-application of biochar and wood vinegar were better than those of the alone application of biochar and wood vinegar.Each treatment increased the proportion of labile phosphorus pool in saline-alkali soil and the proportion of labile phosphorus pool increased with the increase of the amount of wood vinegar.In addition,the application of biochar and wood vinegar increased the 100-grain weight of rice,and C6 treatment had the best effect,increasing the 100-grain weight by 134.35%.Therefore,the application of biochar and wood vinegar in saline-alkali soil could improve the soil phosphorus availability,increase the weight of rice grains,thereby realizing the resource utilization of agricultural waste and the sustainable development of agriculture.
文摘Heavy metals in agricultural soil pose human health risks through food consumption. In a novel study for Trinidad, concentration and pollution index levels of heavy metals were assessed from 18 agricultural farms using the X-Ray fluorescence technique, then to evaluate the Geo-accumulation and Nemerow’s Integrated Pollution indexes. Toxic elements Pb and As were present but soil quality due to anthropogenic input was found as unpolluted. Overall heavy metal pollution was classified at a precautionary level for 33% of farms, slightly polluted for 61% and moderately polluted for 6% of the farms assessed, thus, regular monitoring and mitigation measures are important for food safety and human health in Trinidad.
文摘This study focuses on the use of heavy fuel oil in construction in Burkina Faso.Mixed with silty and/or clay soil,it is used as a coating to reinforce the walls of raw soil constructions which are very sensitive to water.The interest of this paper is to shed light on the thermomechanical and above all water effects of heavy fuel oil on a sample of silty clayey soil.To achieve this,we used heavy fuel oil added in different proportions to silty clayey soil,to make sample of bricks on which tests were carried out.At the end of the experimental tests carried out on materials made(bricks)with our soil sample,it appears that heavy fuel oil moderately reduces the mechanical resistance of bricks and slightly increases thermal diffusion through them.On the contrary,we note a very good water resistance of the bricks thanks to the heavy fuel oil,in particular their water absorption by capillarity.This confirms that the mixture of heavy fuel oil and a silty-clayey soil used as a coating makes it possible to prevent the infiltration of water into the walls of raw soil constructions.However,its use as a construction material does not guarantee very good mechanical resistance,and slightly increases thermal diffusion.
基金funded by the Technology Innovation Special Fund of Jiangsu Province for Carbon Dioxide Emission Peaking and Carbon Neutrality(BE2022307)the National Positioning Observation and Research Project of Forest Ecosystem in Changjiang River Delta,Supported by State Forestry and Grassland Administration of China(2023132077).
文摘Clarifying the soil nutrient dynamics caused by forest type variations in the coastal region helps scientifically to apply fertilizer to forest plantations and enhance the carbon(C)sink capacity.Pure forests of Ligustrum and Metasequoia,as well as their mixed forests,in a coastal region of China were investigated by collecting 0-20 and 20-40 cm soil samples and analyzing their differences in bulk density,water content,pH,soil organic matter(SOM),ammonium(NH_(4)^(+)-N),nitrate(NO_(3)^(-)-N)and total nitrogen(TN),available phosphorus(AP)and potassium(AK),microbial biomass C(MBC)and N(MBN),and enzyme activity.The results demonstrated that different forest types had no significant(p≥0.05)effect on 0-20 cm soil bulk density,water content,pH,NH_(4)^(+)-N,and SOM.However,the surface soil NO_(3)^(-)-N,TN,AP,and AK contents as well as enzyme activity changed significantly(p<0.05),in which the soil AK content of the ligustrum×metasequoia mixed forest was 47.5%and 65.5%higher than that of the ligustrum and metasequoia pure forest,respectively.The mixed forest soil had the highest MBN content,which was significantly(p<0.05)25.1%higher than that in the pure metasequoia forest.Meanwhile,soil phosphatase activities in ligustrum and metasequoia pure forests were significantly(p<0.05)lower than those in the mixed forests by 17.4%and 43.1%,respectively.However,soil NO_(3)^(-)-N and AP contents in the metasequoia pure forest were significantly(p<0.05)higher than those in the ligustrum pure forest and mixed forests.Soil MBC content and reductase NO_(3)^(-)-N activity were significantly(p<0.05)higher in ligustrum pure forest than in metasequoia pure forest and mixed forests.In addition,the results of two-way ANOVA showed that there were no significant(p≥0.05)differences in nutrient contents(e.g.,NH_(4)^(+)-N,AP,AK,and SOM)in different soil layers(0-20 and 20-40 cm)within the same forest type,except for NO_(3)^(-)-N.However,forest types had a significant(p<0.05)impact on NO_(3)^(-)-N and AP contents in 20-40 cm soil layer.Combining the two factors of forest stand and soil layer,there was a significant(p<0.05)interaction effect for their soil NH_(4)^(+)-N,NO_(3)^(-)-N,AP,and AK contents.In conclusion,significant(p<0.05)differences were observed in nutrient contents in 0-20 cm soil layer from different forest types,with soil fertility indices inmixed forests generally higher than in pure forests.Therefore,establishing mixed forests in coastal saline region is recommended to retain soil fertility and to enhance the C sink capacity of forestry.
文摘The aim of this study to investigate the physico-chemical properties of soils from Diguel and Koudalwa Tchad,and phytoremediation potentials of acasia and kinkeliba plants in removing Cr and Cu from these soils.Soil was sampled from the tannery plant in Diguel and agricultural land around crude oil activities in Koudalwa.Soils were characterized by the following properties:pH,(Electrical Conductivity),TDS(Total Dissolved Solids),salinity,bulk density,OM(Organic Matter),nitrate,phosphate,clay,silt,sand,and textural class.The acasia and kinkeliba plants were used to decontaminate Cu and Cr from sample soils for 30 days period.The bulk density of all the soil samples from Kouldawa was higher compared to Diguil,ranging from 1.421 to 1.64 g/cm^(3)compared to 1.21 to 1.51 g/cm^(3)for Diguel.Most of the soils in Kouldawa are mineral soils,while those of Diguel are mostly mineral soil with some organics.Diguel soils are richer in nitrate(577.9 to 2,687.32 mg/kg in Diguel and 33.64 to 197.64 mg/kg in Kouldawa)and phosphate than soils from Kouldawa.Soils from the studied areas are not saline except for a subsurface soil in Diguel(salinity,4.21;EC,4.280 dS/m;TDS,3,040 mg/L).The highest amount of Cr and Cu removed by acasia is 78%and 53.12%compared to 73.8%and 52.21%by kinkeliba.Diguel soil can be very suitable for agriculture and Kouldawa soils for construction.Acasia and kinkeliba can be effectively used to decontaminate the studied soils from heavy metal pollution.
文摘This study aims to investigate the level of soil pollution and the grade of accumulation of metals and heavy metals by wheat plants from the soil in different parts of the crop: root, stem, leaf, spike and grain. Sampling campaigns took place in February, April and July when wheat plants were at different growth stages. A number of eight soil samples and eight wheat plant samples were collected. The sampled wheat plant was taken at the same time and from the same place as the soil. Concentrations of Al (aluminium), Cr (chromium), Mn (manganese), Fe (iron), Ni (nickel), Co (cobalt), Cu (copper), Zn (zinc), Sr (strontium), Cd (cadmium) and Pb (lead) were determined by inductively coupled plasma mass spectrometry. Bioconcentration and translocation factors were calculated for the samples analysed.
基金Supported by National Natural Science Foundation of China(40772160)~~
文摘Through sampling in farmland and analysis in laboratory,the contents and the pollution level of Cr,Cu,As,Pb,Zn in different soils were studied. The comparative result showed that the As in all soil samples are lower than the mean value of Shaanxi and whole nation,the Cr in lower half soil samples are higher than the mean value of Shaanxi and whole nation,the Cu and Zn in majority soil samples are higher than the mean value of Shaanxi and whole nation,and the Pb in all soil samples is higher than the mean value of Shaanxi and whole nation. The single factor pollution index and multi-factor pollution index method were used to evaluate the soil pollution. According to Soil Environmental Quality Standard,the studied soils were at unpolluted degrees,the soils were clear,the quality of soil adapt to the crop growth,and not affect the quality of agricultural product.
文摘Phytoremediation is an efficient and economic ecological technology. It includes phytostabilization, phytovolatilization, and plant absorption. In the research, status quo and progress of Phytostabilization and plant absorption in soils polluted with heavy metals in metal mines were summarized, including the characteristics and status quo of phytoremediation and selection method of hyperaccumulator. In addition, further research was proposed as well.
文摘[Objective] The aim was to study on effects of heavy metals and saline-alkali on growth, physiology and biochemistry of Orychophragmus violaceus. [Method] Taken Orychophragmus violaceus as materials, growth, physiology and biochemistry were explored under stress of saline-alkali and heavy metals (light, moderate and severe saline-alkali, Pb, Pb + Cd, light saline-alkali + Pb, moderate saline-alkali + Pb, severe saline-alkali + Pb, light saline-alkali + Pb + Cd, moderate saline-alkali + Pb + Cd and severe saline-alkali + Pb + Cd) with control group set. [Result] Light stress of saline-alkali had little effect on membrane permeability, as follows: MDA contents in leaves and root systems declined by 25.6% and 9.0% compared with control group; Pb (500 mg/L) stress promoted synthetization of photosynthetic pigments, as follows: chlorophyll a and b and carotenoid increased by 0.86%, 0.69% and 6.25% than those of control group; combined stresses of Pb and Cd destroyed synthetization of photosynthetic pigments, among which carotenoid was more sensitive; under combined stresses of saline-alkali, Pb and Cd, POD and SOD activities, soluble saccharides and Pro content all increased and activities of POD and SOD in root system were both higher than those in leaves. [Conclusion] Orychophragmus violaceus is with resistance against light combined stresses of saline-alkali and Pb (500 mg/L).
文摘ObjectiveThis study aimed to investigate the accumulation of heavy metals from organic fertilizer in soil and plant. MethodThree plots were chosen in Shanghai suburb to measure the heavy metal accumulation by monitoring their concentrations in soil and plant after organic fertilizer was applied. We also analyzed the correlations of the heavy metals in soil and plants. Single-factor pollution index and Nemerow’s synthetical pollution index were adopted to evaluate the heavy metal contamination in soils. Moreover, how many years before the heavy metal accumulation will exceed the environmental capability if 45 t/hm 2 organic fertilizer is applied every year was also estimated in the present study. ResultThe rules of heavy metals’ accumulation in soil changed with the various soil characters and pH. The average concentrations of Pb, Cd and As in the tested plants exceeded the limits. The average concentration of Cu in the tested soil shared positive correlation with that in the tested plants. The average concentration of Pb in the tested soil was negatively correlated with that in the tested plant while the other heavy metals didn’t show the rule like that. Organic fertilizer application caused no obvious pollution to the soils. Cu would exceed the standard environmental capacity within 15 years if 45 t/hm 2 organic fertilizer is applied every year, while for Hg, it will be 2 000 years. ConclusionWhen the excessive organic fertilizer is put into the land, the heavy metals from organic fertilizer would accumulate in soil and plant. With continued excessive fertilization, the heavy metals especially Cu would exceed the stan- dard environmental capacity. More attention should be paid to the inputting amount of the organic fertilizer.