| This dissertation took urban black-odorous river as research object, two typical hydroponic plant purifying tanks(Pontederia cordata, Hydrocotyle vulgaris) were constructed, which were used to carry out the experimental research of urban black-odorous river water purification. Additionally, demonstration project research was carries out. The purposes of this dissertation were to provide theoretical basis and technical support for the technology of the engineering design, system integration and manipulation of urban black-odorous river in situ treatment and ecological restoration.This dissertation was supported by National Science and Technology Major Project of the Ministry of Science and Technology of China during the11th Five-Year Plan (No.2009ZX07317-006). The experimental researches of urban black-odorous river water purification in Shanghai Gongye River were carried out. Additionally, the project of water purification and ecological restoration for Jiushanwai River was implemented. The main investigations of this dissertation were as follows:1) analysis of the physiological properties and morphological characteristics of plants, as well as the changes of water purification effect, to explore the association between the physiological characteristics of plants and water purification effects;2) set artificial aeration as the factor of exogenous regulation, associated the physiological properties and morphological characteristics of plants with the changes of water purification effect, the internal relevance was investigated;3) the method of16S rDNA clone library was used to analyze the diversity of microbial community on the roots of the plant;4) the demonstration project of water purification and ecological restoration for Jiushanwai River was implemented. The main results were as follows:(1) In spring, summer and autumn, as the intensity of the sunlight increased or decreased on diurnal variation, the physiological characteristics of P. cordata and H. vulgaris demonstrated a corresponding up and down. During12:00am to14:00pm, with the increasing on the intensity of sunlight, the contents of Chla, Chlb, and Soluble protein in the leaves of two plants, as well as the activities of CAT, POD and SOD in the roots tissue of two plants were higher than those in other time quantums, respectively. In summer, two plants were observed to display the phenomenon of photosynthesis midday depression which led to a decrease on the contents of Chla, Chlb and Soluble protein in the leaves of two plants at13:00pm. In spring and summer, the content of Soluble protein in the leaves, as well as the activities of CAT and POD in the roots tissue between two plants displayed significant difference (T-Test, p<0.05), respectively. In autumn, the contents of Chla, Chlb and Soluble protein in the leaves of two plants, as well as the activities of POD and SOD in the roots tissue between the two plants showed significant difference (T-Test, p<0.05), respectively. In spring, summer and autumn, the length of the root and stem, the area of the leaves and the biomass of P. cordata were higher than those of H. vulgaris (T-Test, p<0.05), while the number of tillers of the latter was higher than those of the former (T-Test, p<0.05), respectively. In spring and summer, the contents of nitrogen and phosphorous in P. cordata were higher than those of H. vulgaris (T-Test, p<0.05).(2) In spring, summer and autumn, as the intensity of the sunlight increased or decreased on diurnal variation, the effects of water purification of P. cordata and H. vulgaris varied accordingly. During12:00am to14:00pm, the effects of water purification were better than those in other time quantums. In spring, there was no significant difference between the two types of hydroponic plant purifying tanks, excluding the DTP removal efficiency. In summer, the removal efficiencies of CODCr, TN, NH3-N, TP and DTP, as well as the DO concentration in the P. cordata purifying tanks were higher than those of the H. vulgaris purifying tanks (ANOVA,p<0.05) respectively. In autumn, the removal efficiencies of CODcr, TN, NH3-N, TP and DTP, as well as the DO concentration in the P. cordata purifying tanks were higher than those of the H. vulgaris purifying tanks (ANOVA, p<0.05), respectively.(3) In spring, summer and autumn, as the intensity of the sunlight increased or decreased on diurnal variation, the correlations between the effects of water purification and the physiological characteristics of plants demonstrated positive correlation on diurnal variation. To take the experiment of P. cordata in summer as an example:the contents of Chla, Chlb, and Soluble protein in the leaves showed significant positive correlation with the DO concentration in the tanks (r=0.962,0.826,0.953,p<0.05), the activities of CAT, POD and SOD in roots tissue showed significant positive correlation with the removal efficiency of NH3-N (r=0.953,0.945,0.866, p<0.05), and they also demonstrated a close correlation with the removal efficiency of DTP (r=0.954,0.961,0.942, p<0.05). The similar analysis results were concluded in the experiment during spring and autumn.(4) Various treatments of aeration intensities affected the physiological properties and morphological characteristics of two plants differently. In spring, summer and autumn, the physiological properties and morphological characteristics of two plants among45L/min,60L/min and0L/min showed significant difference (ANOVA, p<0.05). In spring, the physiological properties and morphological characteristics of P. cordata were no significant difference between15L/min and0L/min, while the physiological properties and morphological characteristics of P. cordata between30L/min and0L/min showed significant difference (ANOVA,p<0.05), respectively. The physiological properties and morphological characteristics of H. vulgaris were no significant difference between15L/min,30L/min and0L/min. In summer, the physiological properties and morphological characteristics of two plants were no significant difference between15L/min,30L/min and0L/min, respectively. In autumn, the physiological properties of P. cordata were no significant difference between15L/min and0L/min, but the length of the root and stem, the area of the leaves, the biomass, the number of tillers and the content of nitrogen and phosphorous of P. cordata between30L/min and0L/min showed significant difference (ANOVA, p<0.05), respectively; the physiological properties of H. vulgaris were no significant difference between15L/min,30L/min and0L/min, the length of the root and stem, the area of the leaves, the biomass, the number of tillers and the content of nitrogen and phosphorous of H. vulgaris under15L/min were significant higher than those of H. vulgaris under0L/min (ANOVA, p<0.05), respectively.(5) In spring, summer and autumn, various aeration intensities affected the purification effect of two plants obviously. Two types of plant purifying tanks had best purification effect under15L/min. To take the experiment in summer as an example: the removal efficiencies of CODCr, TN, NH3-N, TP and DTP in the P. cordata purifying tank as well as the DO concentration were62.27%,57.08%,66.80%,55.28%and63.70%,4.24mg/L, respectively; while the removal efficiencies of CODcr, TN, NH3-N, TP and DTP in the H. vulgaris purifying tank as well as the DO concentration were58.56%,49.28%,57.89%,52.82%and63.51%,3.95mg/L, respectively.(6) In spring, summer and autumn, two types of plant purifying tank under continuous influent had remarkable effects on the removal efficiencies of DMS and DMDS. To take the experiment in summer as an example:the removal efficiencies of DMS and DMDS in the P. cordata purifying tank under15L/min were76.58%and80.55%, the removal efficiencies of DMS and DMDS in the H. vulgaris purifying tank under15L/min were84.92%and77.81%; the removal efficiencies of DMS and DMDS in the P. cordata purifying tank under30L/min were87.76%and86.02%, the removal efficiencies of DMS and DMDS in the H. vulgaris purifying tank under30L/min were91.35%and84.19%.(7) In spring, summer and autumn, the changes of aeration intensities and seasons had remarkable effects on the diversity of microbial community on the roots of the plant. In summer, the more oxygen was secreted from plant roots during the vigorously growing stage of plant and coupled with higher water temperatures, which led to the more microbial diversities and the better water purification effects in the P. cordata purifying tank. Under30L/min, the diversity of microbial community on the roots of the plant was most in the P. cordata purifying tank; in addition, Nitrospira sp. bacteria was the dominant strain in the P. cordata purifying tank. Additionally, the removal efficiencies of CODCr, TN and NH3-N were highest in the P. cordata purifying tank under30L/min.(8) The demonstration project of water purification and ecological restoration for Jiushanwai River had remarkable effects. During the operation period of the demonstration project, the water quality of demonstration river reach was improved effectively and the black-odorous of river water had been basically eliminated. On the sampling day:2012-06-10, the average concentrations of DO, CODCr,NH3-N and TP in demonstration river reach were4.49mg/L,17.29mg/L,3.34mg/L and0.58mg/L respectively. Additionally, the average concentrations of DO, CODCr, NH3-N and TP in three evaluation sections (Children’s Palace Bridge, Veterinarian Bridge and Sauna Bridge) in demonstration river reach had achieved the objectives and requirements of the demonstration project, respectively.This dissertation was based on the experimental research of urban black-odorous river water purification, which finished an empirical analysis of the dynamic changes of the physiological properties and morphological characteristics of plants in different conditions, as well as the dynamic changes of water purification effect in different condition. Additionally, this dissertation implemented the demonstration project of water purification and ecological restoration for Jiushanwai River. The results of this dissertation provided a reliable basis for the practical engineering application of urban black-odorous river in situ treatment and ecological restoration, which had some theoretical significance and application value. |
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