环保疏浚影响因素分析及其工艺优化研究

发布时间：2018-06-12 09:22

本文选题：钝化剂 + 环保疏浚　；参考：《重庆交通大学》2015年硕士论文

【摘要】：当前,我国江河湖泊的泥沙淤积和污染问题日益严重,特别是长江三峡库区建成以来,泥沙流动率低,库区底泥量增多,同时,点源污染和面源污染问题的共同作用使得三峡库区周围水体污染物进入三峡库区,随着时间的推移,污染物进入底泥造成库区底泥淤积与污染并存,故此,三峡库区的清淤与环境保护问题亟待解决。传统的航道整治技术主要是对航道底泥的疏浚,但是,从环境保护的角度出发,传统的航道疏浚技术存在着对航道底泥的扰动强度大致使底泥悬浮、底泥中富集的污染物重新回到水体、疏浚精度低等诸多问题。因此,为改善航道的疏浚技术在三峡库区的应用问题,应力争在三峡库区航道疏浚过程中降低污染。论文从传统航道疏浚过程中使用的绞吸式疏浚设备出发,结合污染物的治理方法-钝化剂的应用和疏浚设备的改进两方面进行模拟疏浚的试验研究,最终找到疏浚后底泥污染物释放量最小的疏浚模式,同时在疏浚设备和疏浚技术方法两方面找到最优组合。论文系统的从钝化剂对污染物的钝化机理,钝化剂的用量选择,疏浚设备运行参数选择和疏浚工艺优化方面进行试验模拟,最终得出以下结论:1)PAC钝化剂、钙盐钝化剂和铁盐钝化剂三种钝化剂的用量不同对底泥污染物的钝化效果也不尽一致。PAC钝化剂用量为2g/kg、4g/kg、6g/kg底泥投加量下COD污染物抑制率分别为37.42%、43.87%、41.94%,最低的污染物释放量分别可以低至97mg/L、87 mg/L、91 mg/L。钝化剂投加量增加对底泥COD污染物释放量的抑制并非呈线性的增加,而是在钝化剂投加量为4g时最低,这主要因为铝盐的水解程度的有限,铁盐的氧化性也使得其在6g/kg底泥用量时COD释放量最低,钙盐钝化剂投加量则为12g/kg底泥时COD污染物的释放量最低。对于总氮PAC钝化剂在三种用量下的钝化效率分别为29.36%、42.55%、23.38%,钙盐钝化剂在三种用量下的钝化效率分别为30.90%、43.44%、23.66%,铁盐钝化剂在三种用量下的钝化效率为21.54%、41.90%、24.66%。对于总磷PAC钝化剂在三种用量下的钝化效率分别为了71.15%、82.69%、76.92%,钙盐钝化剂在三种用量下的钝化效率分别为61.71%、76.60%、70.21%。三氯化铁对总磷的抑制效果时间较短,在第4天之后,TP量有上升的趋势。对于氨氮三种钝化剂均未见明显的钝化效果。2)绞刀横移速度和转速对疏浚泥浆浓度均有一定影响,其中绞刀横移速度对疏浚泥浆浓度的影响较大。分析得出,能提高绞刀疏浚设备疏浚效率的铰刀转速和横移速度分别为40r/min和200mm/min。3)在四种不同铰刀设备即普通工程铰刀、普通加罩铰刀、环保螺旋铰刀、环保螺旋加罩铰刀与PAC钝化剂和钙盐钝化剂的相结合之后对底泥进行疏浚模拟。其结果为,加入PAC钝化剂后进行疏浚,当上覆水中污染物浓度稳定后,环保加罩铰刀疏浚后的COD污染物释放量分别普通铰刀、普通加罩铰刀、环保铰刀要小24mg/L、15 mg/L、10 mg/L,TN污染物环保螺旋铰刀加罩较其他三种铰刀型式对TN的释放量分别降低了7.46mg/L、2.41mg/L、3.58 mg/L,环保加罩铰刀疏浚后的TP污染物释放量比普通铰刀、普通加罩铰刀、环保铰刀要小0.53mg/L、0.33mg/L、0.40mg/L,环保加罩铰刀疏浚后的NH3-N污染物释放量分别普通铰刀、普通加罩铰刀、环保铰刀要小1.47mg/L、1.10mg/L、0.86mg/L。在加入钙盐钝化剂之后环保加罩铰刀的疏浚模拟COD污染物累积释放量为131mg/L,分别较普通铰刀和其加罩状态下减少了22 mg/L、16 mg/L,环保加罩铰刀在加入钝化剂硝酸钙之后TP的释放量较其他三种形式的铰刀设备分别降低了0.33 mg/L、0.25mg/L、0.31 mg/L,环保加罩铰刀疏浚后的TN污染物释放量分别比普通铰刀、普通加罩铰刀、环保铰刀要小7.38mg/L、4.10mg/L、2.86mg/L,环保加罩铰刀疏浚后的NH3-N污染物释放量比普通铰刀、普通加罩铰刀、环保铰刀要小0.55mg/L、0.52mg/L、0.13 mg/L。由本研究数据分析,疏浚采用环保螺旋加罩铰刀和PAC钝化剂二者相结合的疏浚技术方案为环保疏浚的实施方案。本研究为长江三峡航道回水区淤积底泥环保疏浚施工方案提供了理论依据和技术支撑,研究成果具有重要的理论意义与实用价值。
[Abstract]:At present, the sediment deposition and pollution of the rivers and lakes in our country are becoming more and more serious, especially since the Three Gorges Reservoir area of the Yangtze River is built, the sediment flow rate is low and the sediment in the reservoir area increases. At the same time, the joint effect of point source pollution and non-point source pollution causes the water pollutants around the Three Gorges Reservoir area into the Three Gorges Reservoir area, and the pollutants enter into the Three Gorges Reservoir area. The sediment deposition and pollution in the reservoir area coexist with sediment. Therefore, the problem of siltation and environmental protection in the Three Gorges Reservoir area needs to be solved. The traditional waterway regulation technology is mainly dredging the sediment of the channel, but from the point of view of environmental protection, the traditional dredging technology has the disturbance intensity of the sediment on the channel, and the bottom mud is suspended and the bottom is suspended. In order to improve the application of dredging technology in the Three Gorges Reservoir area, we should strive to reduce pollution in the course of dredging in the Three Gorges Reservoir area. This paper will start from the dredging equipment used in the traditional dredging process and combine the treatment of pollutants. Methods - the application of the passivator and the improvement of the dredging equipment in two aspects, the experimental research on the dredging is carried out, and the dredging mode is found at the end of the dredging. At the same time, the optimal combination is found in two aspects of the dredging equipment and the dredging technology. The system is based on the passivation mechanism of the blunt agent and the use of the passivator. Selection, selection of the operating parameters of dredging equipment and the optimization of dredging process optimization, the following conclusions are obtained: 1) PAC passivator, calcium salt passivator and iron salt passivator, three passivating agents have different passivating effects on the sludge passivation effect, and the dosage of.PAC blunt agent is 2g/kg, 4g/kg, 6g/kg sediment dosage under COD The inhibitory rates of pollutants were 37.42%, 43.87% and 41.94% respectively. The lowest release of pollutants could be reduced to 97mg/L, 87 mg/L, and 91 mg/L. passivating agent added to the release of COD pollutants was not linearly increased, but was the lowest when the dosage of passivating agent was 4G, which was mainly due to the Limited hydrolysis degree of aluminum salt, iron salt. The release of COD is the lowest when the amount of 6g/kg sludge is used, while the dosage of calcium salt passivating agent is the lowest when the amount of COD is added to the base mud of 12g/kg. The passivation efficiency of the total nitrogen PAC passivating agent is 29.36%, 42.55% and 23.38% respectively under three kinds of dosage, and the passivation efficiency of the calcium salt passivating agent under three kinds is 30.90%, 43.44%, respectively. 23.66%, the passivation efficiency of iron salt passivating agent under three kinds of dosage is 21.54% and 41.90%. 24.66%. passivating efficiency for total phosphorus PAC passivating agent under three kinds is 71.15%, 82.69%, 76.92% respectively. The passivation efficiency of calcium salt passivating agent in three kinds is 61.71%, 76.60% and 70.21%. trichloride has a shorter inhibition effect on total phosphorus. After fourth days, the amount of TP has a rising trend. No obvious passivation effect is found on the three kinds of ammonia nitrogen passivating agents. The velocity and speed of the cutter are influenced by the speed and speed of the cutter, and the speed of the cutter's transversal velocity has a great influence on the dredged mud concentration. The transversal velocity is 40r/min and 200mm/min.3 respectively. The dredging is simulated after four different reamer equipment, ordinary engineering reamer, ordinary reamer, environmental helix reamer, environmental spiral reamer with PAC passivating agent and calcium salt passivating agent. The result is that it is dredged after adding PAC passivating agent and when the overlying water is polluted. After the dye concentration is stable, the release amount of COD pollutants after the environmental protection and the reamer dredged is respectively ordinary reamer and ordinary reamer. The environmental reamer should be small 24mg/L, 15 mg/L, 10 mg/L, TN pollutant environmental spiral reamer plus cover is less 7.46mg/L, 2.41mg/L, 3.58 mg/L, environmental protection and reamer dredging than the other three reamers. After the release of TP pollutants, the release amount of the pollutants is higher than that of ordinary reamer and ordinary reamer. The environmental reamer should be small 0.53mg/L, 0.33mg/L, 0.40mg/L, and the release of NH3-N pollutants after the dredging of the environmental protection reamer is used for ordinary reamer, ordinary reamer, and environmental reamer to be small 1.47mg/L, 1.10mg/L, 0.86mg/L. in environmental protection and reamer dredging after adding calcium salt passivating agent. The cumulative release amount of the simulated COD pollutants is 131mg/L, which reduces 22 mg/L and 16 mg/L respectively compared with the ordinary reamer and its cover state, and the release amount of TP after adding the passivating agent calcium nitrate is 0.33 mg/L, 0.25mg/L, 0.31 mg/L, and the TN pollutant after the dredging of the environmental protective reamer and reamer. The release amount is more than ordinary reamer and ordinary reamer. The environmental reamer should be small 7.38mg/L, 4.10mg/L, 2.86mg/L, and the release of NH3-N pollutants after the dredging of the reamer is more than ordinary reamer, ordinary reamer, and environmental reamer should be small 0.55mg/L, 0.52mg/L, 0.13 mg/L. by the analysis of this research data, and the dredging adopts the environmental protection helix reamer and PAC blunt. The combined dredging technology of two chemical agents is the implementation scheme of environmental dredging. This study provides theoretical basis and technical support for the dredging construction scheme of sediment sediment in the backwater area of the Three Gorges waterway. The research results have important theoretical significance and practical value.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U616

【参考文献】