本文關(guān)鍵詞：可滲透反應(yīng)墻滲透性能變化分析與數(shù)值模擬及防治措施的研究　出處：《安徽工程大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 可滲透反應(yīng)墻 滲透速率 數(shù)值模擬 堵塞 防治措施

【摘要】：礦山、矸石山及尾礦壩等周邊地下水受酸性礦井水污染嚴(yán)重。原位治理地下水技術(shù)中可滲透反應(yīng)墻具有處理效果好、安裝施工方便、運(yùn)行成本第等優(yōu)點越來越受到中外學(xué)者及專家的肯定,可以針對不同的地下污染水質(zhì)裝填不同處理作用的活性介質(zhì),其中生物PRB具有高效、環(huán)保,價廉、無二次污染等優(yōu)點受到廣泛重視。但隨之而來的堵塞使PRB不能長期有效地運(yùn)行。本文根據(jù)堵塞機(jī)理在理論上將PRB系統(tǒng)分為三個區(qū)塊(物化區(qū)、生化區(qū)、過濾區(qū))分別進(jìn)行理論分析、設(shè)計實驗?zāi)M各種堵塞導(dǎo)致的滲透性能的變化規(guī)律。(1)物化區(qū)是廢水進(jìn)入PRB系統(tǒng)經(jīng)過的第一個床層,主要對進(jìn)水進(jìn)行預(yù)處理,提高酸性礦井廢水(AMD)的pH值和吸附處理部分重金屬離子,為生化區(qū)減輕負(fù)荷和對微生物的毒理性。所以物化區(qū)不僅要考慮填料釋放堿度的持續(xù)性和對重金屬的吸附,還要考慮滲透速率的變化情況。由實驗結(jié)果可以看出：①通過比較以陶粒為主的1、2#柱和石灰石為主3、4#柱出水pH值的變化規(guī)律可以得出,石灰石在調(diào)節(jié)廢水堿度上不如陶粒,可能是由于石灰石粒度過大導(dǎo)致與水接觸不充分,不能充分溶堿；②根據(jù)pH值的變化規(guī)律,對6個柱子重金屬離子去除率的綜合分析可以看出,沸石、活性炭吸附易飽和,ZVI有更強(qiáng)更持久的去除重金屬能力；③綜合比較6個柱子滲透速率得出滲透速率變化與pH的調(diào)節(jié)幅度和對重金屬的去除率正相關(guān),物化區(qū)堵塞主要由重金屬氫氧化物沉淀導(dǎo)致；④物化區(qū)柱體實驗得出ZVI、陶粒、活性炭配比1：2：4(3#柱)是最優(yōu)的,調(diào)節(jié)pH穩(wěn)定、重金屬去除率高且穩(wěn)定、滲透速率下降幅度小且平緩,因此可以在實際應(yīng)用中采用。(2)通過研究比較國內(nèi)外幾種典型的生物堵塞模型,選擇了兩種適合模擬生化區(qū)滲透速率變化的模型,即修正的微生物PRB堵塞耦合模型和Clement模型。分別設(shè)計室內(nèi)柱體實驗：填料介質(zhì)為大陶粒(3-5mm)：小陶粒(13mm)：玉米芯體積比為1：1：1,接種10%的SRB菌種,控制流量為3mL/min,實驗求解模型中的未知參數(shù)a、b、Km、 n,代入模型計算模擬值。結(jié)果表明：Clement模型能較準(zhǔn)確模擬實驗初期的滲透速率變化；而修正的微生物PRB堵塞耦合模型在實驗后期擬合度較高,所以生化區(qū)滲透性能變化可以用兩個模型共同來模擬。根據(jù)實測值發(fā)現(xiàn),相對滲透速率隨柱子加深逐漸增大,在距離進(jìn)水口10cm處最小。實驗共運(yùn)行了18天,而介質(zhì)相對滲透速率下降不明顯,總體都保持在90%以上,所以說明生物堵塞是一個長期的過程,利用生物PRB原位治理地下水本身就是個經(jīng)濟(jì)有效持久的方法。(3)過濾區(qū)首先通過設(shè)計單因素實驗篩選出對懸濁物過濾效果好且滲透速率下降最小的一組填料配比、進(jìn)水懸濁物濃度、水力停留時間。最終得出陶粒：石英砂=2：1、進(jìn)水懸浮物濃度為150mg/L、水力停留時間為15h為最佳實驗條件。采用最佳實驗條件重新設(shè)計柱體實驗,運(yùn)行了105個小時,每15h測量并計算相對滲透速率,結(jié)果發(fā)現(xiàn)過濾區(qū)的堵塞主要發(fā)生在表層和淺水層,距離填料表面10-20cm、20-30cm、30-40cm深度處相對滲透速率分別從1下降到0.65、0.74、0.90。所以過濾過程中大部分懸濁顆粒被表淺層介質(zhì)截留吸附,按水流方向濃度逐漸減小。本章結(jié)合地下水滲流方程、懸濁物質(zhì)量運(yùn)移方程、懸濁物的吸附脫附方程,用多物理場軟件COMSOL耦合求解,與實測值擬合效果較好,所以該一系列方程可以用來模擬過濾區(qū)堵塞過程。(4)通過借鑒國內(nèi)外專家學(xué)者關(guān)于垃圾滲濾液回灌、尾礦壩等一系列成功的防治堵塞措施,并根據(jù)本文各分區(qū)實驗得出適合各分區(qū)的一系列防治措施。其中,物化區(qū)根據(jù)其在PRB中的作用選擇合適的介質(zhì)種類、粒徑和配比來預(yù)防堵塞的發(fā)生,用反沖洗法或超聲波法來緩解床層內(nèi)部堵塞,在運(yùn)行一段時間后當(dāng)填料釋堿能力慢慢減弱且滲透速率減小時還可以更換填料；生化區(qū)堵塞的預(yù)防措施可以采用適當(dāng)改變介質(zhì)初始孔隙、初始接種菌量、進(jìn)水有機(jī)營養(yǎng)物濃度,為了防止微生物數(shù)量泛濫,還可以采取間歇運(yùn)行,保持床體干燥來抑制微生物的過度生長,而生化區(qū)堵塞可以設(shè)置清淤裝置；過濾區(qū)可以選用合適的介質(zhì)種類配比、粒徑、調(diào)整進(jìn)水水質(zhì)和水流速度等措施來預(yù)防堵塞的發(fā)生,而過濾區(qū)堵塞主要發(fā)生在表層淺層,可以采用反沖洗法、定期更換部分介質(zhì)等方法來治理堵塞。
[Abstract]:The surrounding ground water of mine, Gangue Mountain and tailings dam is polluted seriously by acid mine water. Osmotic reaction wall has good treatment effect, convenient installation and construction and operation cost of the advantages of more and more Chinese and foreign scholars and experts will be in situ groundwater treatment technology, the active medium for filling in different underground water pollution treatment effect, which PRB has the advantages of high efficiency, environmental protection, low cost, no two pollution etc. has received extensive attention. But the concomitant blockage makes it impossible for PRB to run effectively for a long time. Based on the blockage mechanism, the PRB system is divided into three blocks (materialized area, biochemical area and filter area). Theoretical analysis and design experiments are carried out to simulate the change rule of permeability caused by various plugging. (1) the physicochemical area is the first bed that the wastewater passes into the PRB system. It mainly pretreated the influent, increased the pH value of acid mine drainage (AMD) and adsorbed some heavy metal ions, which reduced the load and the toxicity of microorganisms to the biochemical area. Therefore, the physicochemical area should not only consider the continuity of the alkalinity of the packing and the adsorption of heavy metals, but also consider the change of the permeation rate. The experimental results show that: through the comparison with ceramsite based 1 2# column, and limestone as the main changes of the 3 4# column, the pH value of the effluent can be drawn, limestone in the regulation of wastewater alkalinity than ceramsite, probably due to excessive lead lime stone particle contact with water is not sufficient, not fully according to the change of alkali; the characteristic value pH, comprehensive analysis on the removal rate of the 6 pillars of heavy metal ions can be seen, zeolite, activated carbon adsorption saturation, ZVI has stronger and more persistent heavy metal removal ability; the comprehensive comparison of 6 pillars permeation rate through adjusting amplitude permeation rate with the change of pH and the heavy metal removal rate is related to. The area is mainly composed of heavy metal hydroxides leads to clogging; the physicochemical zone column experiment of ZVI, ceramic, activated carbon ratio 1:2:4 (3# column) is the optimal regulation of pH stability, the removal rate of heavy metal It can be used in practical application because of its high stability and low penetration rate. (2) by studying and comparing several typical models of biological clogging at home and abroad, two models suitable for simulating the change of osmotic rate in biochemical area were selected, that is modified microbial PRB clogging coupling model and Clement model. Indoor column experiments were designed respectively: packing medium was 3-5mm, 13mm: corncob volume ratio was 1:1:1, inoculated with 10% SRB strains, and control flow rate was 3mL/min. The unknown parameters of a, B, Km and N were solved in experiment. The results showed that the Clement model could accurately simulate the infiltration rate in the early stage of the experiment, while the modified microbial PRB clogging coupling model was higher in the later stage of the experiment, so the permeability change in the biochemical area could be simulated by two models. According to the measured values, the relative permeation rate increases with the depth of the column, and is the smallest at the distance to the 10cm. The experiment lasted for 18 days, and the relative permeability rate of the medium decreased less than 90%. Therefore, bioplugging is a long-term process. Using biological PRB to control groundwater in situ is an economic and effective method. (3) filter area first designed a single factor experiment to screen out a set of packing ratio, influent suspension concentration and hydraulic retention time. It is concluded that the best experimental conditions are quartz sand =2:1, concentration of water suspended substance 150mg/L, and hydraulic retention time of 15h. Re column designing experiment using the optimum experimental conditions, running 105 hours, each 15h measurement and calculation of relative permeability rate, it is found that the blocking filtration area mainly occurred in the surface and shallow layer distance, 10-20cm, 20-30cm, 30-40cm surface depth relative permeability rate decreased from 1 to 0.65, 0.74, 0.90. Therefore, most of the suspended particles in the filtration process are intercepted by the shallow layer medium, and gradually decrease according to the direction concentration of the flow. Combined with the groundwater seepage equation, the mass transport equation of suspended matter and the adsorption and desorption equation of suspended solids, this chapter solves the problem of blockage in the filtration area by using the multi physical field software COMSOL, and the fitting results are good with the measured values. (4) by drawing on a series of successful measures for prevention and control of leachate recirculation and tailings dam at home and abroad, a series of preventive measures for each sub area are obtained based on the experiments in different regions. Among them, the materialized area according to its role in PRB media type, choose appropriate particle size and ratio to prevent blockage, to alleviate the bed internal blockage by backwash method and ultrasonic method, after running for a period of time when the filler release capability of alkali slowly weakens and the penetration rate decreases when can also replace the packing biochemical; zone blocking preventive measures can be used to change the appropriate medium initial porosity, initial inocula and influent organic nutrient concentrations, in order to prevent the spread of microorganisms, can also be used in intermittent operation, keep the excessive growth of the bed body drying to inhibit microbial and biochemical zone blocking can set the dredging device; the filtering area ratio, can be selected medium type suitable particle size, adjust the water quality and water flow rate and other measures to prevent the occurrence of clogging, and filtration zone blocking occurs mainly in the shallow surface, can be used to counter The method of washing and replacing part of medium to control the clogging.
【學(xué)位授予單位】：安徽工程大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：X523

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本文編號：1343583