| Liaohe River Wetland is the Liaohe River into the final flow of the Bohai Sea.The area,the upper reaches of the construction.There are large-scale paper mills,many.Along the river.Distribution,discharge of wastewater.Has become an irrigation wetland.,The study found that the discharge of heavy metals in wastewater has been significantly more than the national sewage integrated.Emission.? grade standards,the downstream wet.To cause serious pollution.Heavy metal is not easy to self-degradation or microbial decomposition,most of the sub-deposition in the water or aquatic plants to absorb and accumulate in the body,when the heavy metal content of more than a certain range,the plant will produce toxic effects,Symptoms,affecting plant growth and active oxygen metabolism system balance,causing damage to the plant,in serious cases may cause plant death.In this study,we studied the wetland papermaking wastewater inflow from Liaohekou wetland in Liaoning province,and studied the effects of papermaking wastewater on the growth and physiological characteristics of Phragmites australis and the accumulation and distribution of heavy metals in different parts of Phragmites communis.Indicators and physiological indicators of heavy metal response to aquatic plants to repair heavy metal pollution to provide a scientific basis for wetland water pollution prevention and improvement to provide technical support.The main findings are as follows:(1)The growth of reed was promoted by the extraction of papermaking wastewater.With the increase of the concentration of papermaking wastewater,the stem diameter,plant height,leaf area and biomass of reed were significantly increased,300 mg · L-1 wastewater was thick,The plant height,leaf area and biomass were 185.53cm,0.53cm,132.39cm2 and 12.98kg respectively,which were 2.55.2.04,1.25 and 2.71 times of the corresponding control group.The growth indexes were proportional to the irrigation concentration,300 mg·L-1 concentration range,the higher the irrigation concentration reed plant growth is better.(2)50 and 175 mg·L-1papermaking wastewater enhanced the conversion efficiency and potential activity of the reaction center of the phyllostachysystem II of the reed leaves,and 300 mg·L-1 wastewater irrigation,Fv/Fm and Fv/Fo compared with the control group Down 8.19%and 24.94%,the light system II function decreased.Fluorescence parameters Fv/Fm and Fv/Fo showed decreasing trend of 6.22%and 29.47%respectively with the growth period of Phragmites australis,and the difference of Fv/Fm between the five growth stages of Phragmites australis was not significant(P<0.05),indicating that the Fv/Fm value of the reed plant was relatively stable at the whole growth period,and the effect of Fv/Fm on the growth period was relatively small,and the reed The Fv/Fo value of Fv/Fo was higher than that in the early growth period,and the Fv/Fo value was more sensitive to the growth period of Phragmites australis.(3)The contents of free proline and soluble protein in reed and leaf osmotic adjustment were significantly higher than those in the control group(P<0.05).The higher the concentration of wastewater,the higher the content of free proline and soluble protein The content of free proline increased first and then decreased,and the irrigation concentration had a great influence on the content of waste water,and the flowering stage increased by 10.35,15.79.24.94 mg.g-1(P<0.05),and the soluble protein content increased first and then decreased.The difference was not significant(P<0.05).The content of free proline and soluble protein in the roots was lower than that in the leaves,while the soluble sugar content was higher than that of the leaves.The content of free proline and soluble protein in the roots increased gradually.In the 300 mg L-1 irrigation group,Water irrigation group 2.94,1.33 times.(4)papermaking wastewater irrigation as a whole improves the leaf production rate.The O2-production rate and MDA were the highest in the leaf stage and heading flowering stage,and the difference was not significant(P<0.05),but the difference was not significant(P<0.05).The values of active oxygen products in the irrigation group were 4.07?mol·g-1 and 16.67?g·g-1,respectively.The activity of root active oxygen was higher than that of leaf,O2-production rate and MDA were the highest at the jointing stage,and the irrigation group was 9.08?mol·g-1 and 17.43?g·g-1 in 300 mg·L-1,1.56 times,the papermaking wastewater irrigation to leaf and root active oxygen product accumulation,but the rising trend is not obvious,did not cause damage to cells peroxidation.(5)The activities of antioxidant enzymes in the leaves of Phragmites australis were significantly higher than those in the control group,and the activities of SOD and CAT in the leaves were the highest.The control group of the 300 mg·L-1 control group was 4.29,1.40 times,And the activities of SOD and CAT in roots were the highest at jointing stage and mature stage,which was 4.11 and 2.96 times of control group.Leaf and root POD activities were the highest at the leaf stage and jointing stage,respectively.The 300 mg·L-1 irrigation group was 2.32,1.91 times of the corresponding growth period in the control group.(6)The greater the concentration of papermaking wastewater,the higher the heavy metal content of the reed,the higher the content of heavy metal zinc,chromium,copper,iron,lead and manganese in the reed roots during the jointing stage,(P<0.05).The effects of heavy metals on the contents of chromium,copper,lead,zinc and iron in the stem were not significant(P<0.05)The ability of enrichment of heavy metals in the leaf stage was strong,and the heavy metals in the scion were shifted to the pan.The transporting coefficients of zinc,chromium,copper,iron and lead were 0.75,1.22,0.40,23.37,2.18 and 0.99 respectively,which indicated that the transport characteristics of different heavy metals in Phragmites communis were different.The transfer coefficient of the whole growth period is more than 1,and the chrome quasi-pass coefficient is small,the papermaking wastewater irrigation does not promote the transfer of heavy metal manganese,the transport coefficient is less than the irrigation group.Long-term inclusions in the perennial chrome,lead and manganese 81.10?90.59%was fixed in the roots,copper,iron and zinc to the ground transfer ability,perennial accumulation of manganese and zinc were released from the body.(7)The heavy metals in leaves and roots had a great influence on the physiological indexes,and the effects of copper on the soluble sugar,active oxygen accumulation products and antioxidant enzymes were significant.Copper transport capacity is low,the transport coefficient is 0.40 less,mainly concentrated in the roots,and the heavy metal zinc transport and enrichment characteristics and copper similar,but the impact of physiological indicators of the root,indicating that the physiological characteristics of reed not only by heavy metal transport capacity and enrichment characteristics and be related to the chemical nature of heavy metals themselves... |
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