铝盐混凝剂在给水处理中残留铝含量、组分及影响机制研究

发布时间：2018-06-06 00:50

本文选题：铝盐混凝剂 + 残留铝组分　；参考：《山东大学》2013年博士论文

【摘要】：本论文在综述国内外大量文献的基础上,首先建立并确定了净化水中不同组分残留铝的分离及测定方法,然后针对腐植酸-高岭土模拟地表水和不同季节引黄水库水的特点,对比研究了混凝剂种类、混凝剂合成条件、混凝剂投加量、水体初始pH及水力条件对混凝效果、残留铝含量、残留铝组分及余铝率的影响；从混凝效果和不同组分残留铝含量分别确定了各铝盐混凝剂处理不同地表水的最佳投加量以及最佳处理pH,并明确了各铝盐混凝剂在不同季节引黄水库水处理中的最佳作用水力条件；同时分析了影响残留铝含量的主要因素,探讨了混凝效果(絮体特性操作参数)与各组分残留铝浓度之间的关系。主要结论如下： 1.在腐植酸-高岭土模拟地表水混凝处理中,氯化铝、硫酸铝和聚合氯化铝(PAC)在不同投加量下的浊度和UV254去除率最高可达90%左右；PAC投加量较高时混凝效果较好,其混凝出水巾残留总铝量(约为0.9mg/L)和余铝率(-3.0%)均是三种混凝剂巾最低的,且PAC能够有效降低出水巾毒性较大的溶解性铝的含量(约为0.6mg／L)；在pH为6.0-7.0之间,氯化铝、硫酸铝和PAC的浊度去除率分别可达到94%,91.5%和90.5%,UV254去除率可分别达到87%,88.5%和82%；不同pH下PAC混凝出水中残留铝含量及余铝率最低；三种混凝剂在投加量范围为10-12mg／L下处理腐植酸-高岭土模拟地表水时可以取得最佳的混凝去除效果和最低的残留铝含量；但它们取得最佳混凝效果和最低残留铝含量的pH范围分别为6.0-7.0和7.0-8.0；三种混凝剂净化后水中残留铝均大部分以溶解性总铝的形式存在(约60%-80%),溶解性有机铝在总溶解性铝巾所占比例较大,溶解性单体铝组分基本均为溶解性无机单体铝。 2.PAC更适于春秋季节引黄水库水混凝处理,不同投加量和pH下具有比传统氯化铝混凝去除率更高、电中和能力更强、残留铝含量更低、混凝剂本身余铝率更低和对水体pH改变的适应性更强的优点；氯化铝和PAC的电中和能力在酸性条件下更强,两种混凝剂混凝出水中大部分是亲水性有机物,增加投加量以及中性和偏碱性条件更利于疏水性有机物的去除；不同条件下PAC中的铝不易残留,余铝率均明显低于氯化铝的余铝率,但其混凝出水中溶解性有机结合铝含量较高；PAC在春秋季节引黄水库水处理中,取得较好混凝效果的碱化度(B)为2.0、投加量范围为12-15mg/L、初始水体pH为6.0左右；净化后水中残留铝均大部分以溶解性总铝的形式存在,且溶解性有机铝在总溶解性铝中所占比例较大,溶解性单体铝主要以溶解性无机单体铝为主；各组分残留铝浓度及混凝剂余铝率均在投加量为12～15mg/L、pH为7.0-8.5下较低,可有效控制混凝出水中的残留铝含量；此外,B值为2.0的PAC在春季水库水处理巾余铝率较低。 3.在冬季低温低浊引黄水库水处理中,聚硅氯化铝(PASiC)以吸附架桥和卷扫絮凝为主，B值为2.0、硅铝摩尔比为0.05时PASiC具有更好的混凝效果和更低的残留铝含量；不论B值和硅铝摩尔比如何变化,PASiC均在投加量范围为12-15mg/L、初始pH为6.0-7.0时对引黄水库水中的浊度和有机物具有良好的去除效果,而在投加量为10～15mg/L、初始pH为7.0-8.5下PASiC混凝后水巾含有较低浓度的残留铝；PASiC更适宜于去除水库水巾疏水性和具有芳香族特性的大分子有机物;PASiC在冬季低温低浊引黄水库水处理中,混凝出水巾残留铝中大部分是总溶解性铝,在总溶解性铝中溶解性单体铝的成分最大,溶解性单体铝主要以溶解性无机单体铝为主;同使用PAC处理春秋季引黄水库水相比,使用PASiC(?)昆凝处理冬季低温低浊引黄水库水时混凝剂的最佳投加量较高 4.在夏季高藻引黄水库水处理中,向PAC中引入聚二甲基二烯丙基氯化铵(PDMDAAC)后制备出的聚合氯化铝-聚二甲基二烯丙基氯化铵(PAC-PDMDAAC)复合混凝剂的混凝特性受无机有机组分质量比(MR值)及B值的影响,B值为2.0、MR值为4：1时复合混凝剂的混凝效果较好；PAC-PDMDAAC处理夏季高藻引黄水库水的最佳投加量为6mg/L,最佳水体pH为6.0左右；B值为2.0、MR值为4：1的PAC-PDMDAAC()昆凝出水巾不同组分残留铝含量较低,更易降低出水中残留铝的浓度；投加量与pH值对复合混凝剂在水体中的残留铝量有一定的影响,在投加量为6-8mg／L、初始pH为7.0-8.5的条件下可有效控制净化水中残留铝含量；混凝剂混凝出水中残留铝中大部分是总溶解型铝,总溶解性铝溶解性有机铝成分最大,溶解性单体铝主要以溶解性无机单体铝为主。 5.总铝、总溶解性铝、溶解性单体铝及溶解性有机铝的浓度随混凝沉淀水力条件的变化呈现出了不同的变化规律；从残留铝含量及组分分布来看,快速搅拌强度、快搅时间、慢速搅拌强度、慢速搅拌时间和沉淀时间对水中不同组分残留铝的含量具有不同程度的影响。使用PAC和PASiC处理相应季节引黄水库水中选择快速搅拌转速为200r/min、快速搅拌时间为1min、慢速搅拌转速为40r/min、慢速搅拌时间为15min时对不同组分残留铝的控制效果最佳；使用PAC-PDMDAAC处理夏季引黄水库水巾选择快速搅拌转速为100～200r/min、快速搅拌时间为1min、慢速搅拌转速为40～50r/min、慢速搅拌时间为15～20min、时能够使PAC-PDMDAAC(?)争化后水中含有较低浓度的残留铝：相对于混凝过程,沉淀过程对残留铝组分的影响略小。综合考虑水处理工艺的实际运行情况及不同残留铝组分的浓度,在使用不同的铝盐混凝剂处理相应季节引黄水库水中应选择沉淀时间为30min较好。 6.使用同种混凝剂在不同水体pH下处理引黄水库水时存在一个最佳粒径、强度、生长速度和浊度去除率使净化后水中总铝和颗粒态铝浓度最低。复合混凝剂中MR=2：1时最佳粒径为335～347μm、最佳生长速度为35.2～35.7μm/min、最佳絮体强度为30、最适浊度去除率为75.2%-76.1%；MR=4：1时该最佳粒径为342-381μm、最佳生长速度为38.5～47.7μm/min、最佳絮体强度为26、最适浊度去除率为78.6%-80.9%；MR=8：1时该最佳粒径为278～300μm、最佳生长速度为32.1-33.7μm/min、最佳絮体强度为33、最适浊度去除率为74.6%-75.1%。在某一水体pH下采用具有不同MR值的复合混凝剂处理引黄水库水时,絮体粒径和生长速度越大、强度越低、浊度去除率越高,相应组分残留铝浓度尤其是颗粒态铝浓度越低；颗粒态铝浓度与絮体粒径或生长速度之间均呈现较明显的负线性相关性,其与絮体强度之间呈现较明显的正线性相关性；同种混凝剂下影响残留铝浓度的最主要因素是pH变化引起铝溶解度的变化；在某水体pH下采用不同MR值的混凝剂处理引黄水库水时影响铝浓度的最主要因素是混凝去除效果；溶解态有机结合部分残留铝的浓度与有机物去除率之间以及颗粒组分残留铝浓度与浊度去除率之间均呈现较弱的负线性相关性。
[Abstract]:On the basis of a large number of documents at home and abroad, this paper first established and determined the separation and determination of the residual aluminum in different components of the purified water. Then, in view of the characteristics of humic acid kaolin in the simulation of surface water and the water of the Yellow River Reservoir in different seasons, the coagulant species, the conditions of coagulant synthesis, the dosage of coagulant and the water body were compared. The effect of initial pH and hydraulic conditions on the coagulation effect, the residual aluminum content, the residual aluminum composition and the residual aluminum ratio, and the optimum dosage and the optimal treatment pH for the treatment of different surface water by the aluminum salt coagulant from the coagulation effect and the residual aluminum content of different components, and the water treatment of various aluminum salt coagulants in different seasons of the Yellow River reservoir, respectively. At the same time, the main factors affecting the content of residual aluminum were analyzed, and the relationship between the coagulation effect (the operating parameters of floc characteristics) and the residual aluminum concentration in each component was discussed. The main conclusions are as follows:
1. in the mixture of humic acid and kaolin simulated surface water, the turbidity and UV254 removal rates of aluminum chloride, aluminum sulfate and poly aluminum chloride (PAC) are up to about 90% in different dosage, and the coagulation effect is better when the dosage of PAC is higher, and the residual total aluminum content (about 0.9mg/L) and the residual aluminum ratio (-3.0%) of the coagulated water towel are three kinds of coagulant towels At the lowest level, PAC can effectively reduce the content of dissolved aluminum (about 0.6mg / L) in the effluent towel, and the turbidity removal rate of aluminum chloride, aluminum sulfate and PAC can reach 94%, 91.5% and 90.5% respectively in pH 6.0-7.0, and the removal rate of UV254 can reach 87%, 88.5% and 82% respectively; the residual aluminum content and residual aluminum in water under different pH are coagulated under different pH. The three coagulants can obtain the best coagulation removal effect and the lowest residual aluminum content when the three coagulants treat humic acid and kaolin under the dosage range of 10-12mg / L, but the optimum coagulation effect and the minimum residual aluminum content are 6.0-7.0 and 7.0-8.0, respectively, and the three coagulants are purified after the water. Most of the residual aluminum exists in the form of total dissolved aluminum (about 60%-80%), and the proportion of dissolved organic aluminum in total dissolved aluminum is larger, and the soluble monomer aluminum is basically dissolved inorganic aluminum.
2.PAC is more suitable for water coagulation treatment in the spring and autumn season. Under different dosage and pH, the removal rate of coagulation is higher than that of traditional aluminum chloride, the electric neutralization capacity is stronger, the residual aluminum content is lower, the coagulant itself has a lower aluminum ratio and the adaptability to the water pH change is stronger. The electric neutralization capacity of aluminum chloride and PAC is under the acid condition. Most of the two coagulants in the coagulant effluent are hydrophilic organic matter. Increasing the dosage and neutral and alkaline conditions is more conducive to the removal of hydrophobic organic matter. Under different conditions, the aluminum in PAC is not easy to remain, and the residual aluminum ratio is obviously lower than that of aluminum chloride, but the content of dissolved organic aluminum in coagulant water is higher; P In the water treatment of the Yellow River Diversion reservoir in the spring and autumn season, the alkalinity (B) of better coagulation effect was 2, the dosage range was 12-15mg/L and the initial water body pH was about 6. The residual aluminum in the water after purification was mostly dissolved in the form of total dissolved aluminum, and the proportion of dissolved organic aluminum in total dissolved aluminum was larger, and the soluble monomer aluminum was main. The residual aluminum concentration and the residual aluminum ratio of the coagulant are 12 ~ 15mg/L and pH under 7.0-8.5, which can effectively control the residual aluminum content in the coagulant effluent. In addition, the PAC of the B value of 2 is lower in the spring reservoir water treatment towel.
3. in the water treatment of low temperature and low turbidity yellow reservoir in winter, polysilicon chloride aluminum chloride (PASiC) is mainly adsorbed on bridge and scavenging flocculation, B value is 2, and the molar ratio of silicon aluminum to 0.05 PASiC has better coagulation effect and lower residual aluminum content. No matter how the B value and the molar ratio of silicon aluminum change, PASiC is 12-15mg/L in the dosage range, and the initial pH is 6. -7.0 has a good removal effect on turbidity and organic matter in the water of the Yellow River, while the dosage is 10 ~ 15mg/L, and the initial pH is 7.0-8.5 PASiC mixing with a lower concentration of residual aluminum; PASiC is more suitable for removing the hydrophobicity of the reservoir water towel and the macromolecular organic matter with aromatic characteristics; PASiC is low temperature and low turbidity in winter. In the water treatment of the Yellow River reservoir, most of the residual aluminum in the coagulated water towel is total dissolved aluminum, and the composition of dissolved monomer aluminum in total dissolved aluminum is the largest. The soluble monomer aluminum is mainly dissolved inorganic monomer aluminum. Compared with the use of PAC in the spring and autumn season yellow river reservoir water, PASiC (?) Kun condensate is used to treat the low temperature and low turbidity yellow reservoir in winter. The best dosage of coagulant is higher in water
4. in the water treatment of high algal yellow reservoir in summer, the coagulation characteristics of polyaluminum chloride poly two methyl diallyl ammonium chloride (PAC-PDMDAAC) compound coagulant prepared from PAC after the introduction of polymethyl diallyl ammonium chloride (PDMDAAC) into the Yellow River reservoir water is affected by the mass ratio of the inorganic units (MR) and B, the B value is 2, and the MR value is 4:1. The coagulant effect of the agent is better; the optimum dosage of PAC-PDMDAAC to treat the water of the high algae Yellow River in summer is 6mg/L, the optimum water body pH is about 6, the B value is 2, the PAC-PDMDAAC () of PAC-PDMDAAC () of 4:1 in the PAC-PDMDAAC () Kun Ning water towel is lower, and the concentration of the residual aluminum in the effluent can be reduced more easily; the dosage and pH value are used for the compound coagulant in the water. The residual aluminum content in the body has a certain influence. The residual aluminum content in the purified water can be effectively controlled under the dosage of 6-8mg / L and the initial pH 7.0-8.5. The most of the residual aluminum in the coagulant coagulating water is total dissolved aluminum, the total dissolved aluminum dissolved in the total dissolved aluminum is the largest, and the soluble monomer aluminum is mainly dissolved inorganic monomer. Aluminum is the main.
5. the concentration of total aluminum, total dissolved aluminum, dissolved monomer aluminum and dissolved organic aluminum varied with the change of hydraulic conditions. From the content of residual aluminum and the distribution of components, the fast stirring intensity, fast stirring time, slow stirring intensity, slow stirring time and precipitation time were used for the residual aluminum in different water components. The effect of PAC and PASiC on the selection of rapid stirring speed of 200r/min, rapid stirring time of 1min, slow stirring speed of 40r/min, and slow stirring time of 40r/min and 15min for different components of residual aluminum in the water diversion reservoir water in the corresponding season are the best, and the use of PAC-PDMDAAC to treat the summer yellow reservoir in the Yellow River with PAC-PDMDAAC is used. The quick stirring speed of 100 ~ 200r/min, rapid stirring time of 1min, slow stirring speed of 40 ~ 50r/min and slow stirring time of 15 ~ 20min can cause PAC-PDMDAAC (?) to contain low concentration of residual aluminum in water, and the influence of precipitation process on residual aluminum composition is slight. To deal with the actual operation of the process and the concentration of different residual aluminum components, the precipitation time should be 30min better when using different aluminum salt coagulants to treat the water diversion reservoir water in the corresponding season.
6. when using the same coagulant to treat the water of the Yellow River Reservoir under the pH of different water bodies, there is a best particle size, the strength, the growth rate and the removal rate of turbidity make the concentration of the total aluminum and the granular aluminum in the water the lowest. The optimum particle size is 335~347 mu m in the compound coagulant, the optimum growth rate is 35.2 to 35.7 mu m/min, and the optimum floc strength is the strength of the flocculant. 30, the optimum removal rate of turbidity is 75.2%-76.1%, and the optimum particle size is 342-381 mu m, the optimum growth rate is 38.5 ~ 47.7 mu m/min, the optimum floc strength is 26, the optimum turbidity removal rate is 78.6%-80.9%, the optimum particle size is 278~300 m, the optimum growth rate is 32.1-33.7 u m/min, the optimum floc strength is 33, the optimum turbidity is 33, and the optimum turbidity is the best. When the removal rate is 74.6%-75.1%. in a water pH with different MR values of compound coagulant, the larger the particle size and growth speed of the floc, the lower the intensity, the higher the turbidity removal rate, the lower the residual aluminum concentration in the corresponding components, especially the particle aluminum concentration, and the grain state aluminum concentration and the floc size or growth speed. There is a obvious negative linear correlation, which has a obvious positive linear correlation with the strength of the floc; the most important factor affecting the residual aluminum concentration under the same coagulant is the change of the solubility of aluminum caused by pH, and the main cause of the effect of the coagulant with different MR values under the pH of a water body to treat the water in the yellow water reservoir There is a weak negative linear correlation between the concentration of partial residual aluminum and the removal rate of organic matter as well as the residual aluminum concentration and turbidity removal rate of the dissolved organic combination.
【学位授予单位】：山东大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TU991.2

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