【摘要】：鉛具有生物毒性,含鉛廢水進(jìn)入環(huán)境后不能被微生物降解,只能發(fā)生形態(tài)間的相互轉(zhuǎn)化、分散和富集,并且沿生物鏈傳遞,通過皮膚、消化道、呼吸道進(jìn)入人體體內(nèi)與多種器官親和積蓄。但鉛是自然界分布很廣的元素,常被用作制造業(yè)的原料。若不妥善安全處置含鉛廢水必然會(huì)給環(huán)境帶來極大的危害。因此,需尋找一種安全可靠且經(jīng)濟(jì)有效的方式處理含鉛廢水。鋼渣是煉鋼過程中排出的熔渣,分為轉(zhuǎn)爐渣、平爐渣、電爐渣三種,長期以來被作為固體廢物處置。本實(shí)驗(yàn)用XRF、XRD、SEM、BET等測(cè)試方法觀察轉(zhuǎn)爐渣的成分及微觀形貌,可知,鋼渣表面粗糙多孔,具有一定的吸附能力；鋼渣的化學(xué)成分主要有CaO、SiO2;鋼渣置于水中呈堿性,對(duì)水溶液中的鉛離子具有一定的化學(xué)沉淀作用；鋼渣的礦物成分主要有C2S、C3S,與硅酸鹽水泥熟料相似,可作為混合材料制備鋼渣水泥。故利用鋼渣處理含鉛廢水,探索吸附鉛離子鋼渣制備鋼渣水泥用作建筑材料的可行性。針對(duì)高濃度含鉛廢水,本論文用氧化鋁助改、高溫活化、酸浸三種改性方法對(duì)鋼渣改性,提高鋼渣的吸附性能。硫酸對(duì)鋼渣的改性效果最好,最佳改性條件為氫離子濃度0.32mol/L。通過靜態(tài)實(shí)驗(yàn)對(duì)改性鋼渣處理高濃度含鉛廢水的操作條件進(jìn)行了優(yōu)化選擇。結(jié)果表明：鋼渣的投加量、反應(yīng)時(shí)間、反應(yīng)溫度對(duì)吸附效果有較大影響,鉛離子與鋼渣的最佳投加比僅為1：6,在200min時(shí)達(dá)到吸附平衡,最佳反應(yīng)溫度為25℃。溶液初始濃度和初始pH對(duì)吸附效果影響不大。結(jié)合吸附等溫線模型、吸附動(dòng)力學(xué)模型、化學(xué)沉淀原理、實(shí)驗(yàn)現(xiàn)象及表征分析,探討了鋼渣處理含鉛廢水的作用機(jī)理。鋼渣吸附鉛離子的過程屬于單分子層吸附,符合Langmuir模型和偽二級(jí)動(dòng)力學(xué)模型。鋼渣處理含鉛廢水的機(jī)理主要包括化學(xué)沉淀和離子交換作用。本文重點(diǎn)解決了吸附鉛離子鋼渣穩(wěn)定化、無害化、資源化處理的難題,將吸附重金屬鉛離子鋼渣混合材制備成鋼渣水泥,尋找了一個(gè)經(jīng)濟(jì)、低碳、環(huán)保的廢渣資源化利用新途徑。通過對(duì)鋼渣水泥的物理性能測(cè)試、XRD、SEM表征、水化熱、孔結(jié)構(gòu)分析以及水泥中鉛離子浸出毒性測(cè)試,研究其作為建材應(yīng)用的可行性。結(jié)果表明：鋼渣水泥的各項(xiàng)物理性能均滿足GB 175-2007《通用硅酸鹽水泥標(biāo)準(zhǔn)》：摻雜10%鋼渣時(shí),水泥強(qiáng)度能達(dá)到52.5R；摻雜40%鋼渣時(shí),水泥強(qiáng)度能達(dá)到42.5R；未出現(xiàn)異常水化產(chǎn)物；吸附有鉛離子的鋼渣未導(dǎo)致水泥水化延遲；且鋼渣水泥中的鉛離子在酸性和中性環(huán)境下的浸出濃度均滿足GB5085.3-2007《危險(xiǎn)廢物鑒別標(biāo)準(zhǔn)-浸出毒性鑒別》標(biāo)準(zhǔn)。
[Abstract]:Lead is biotoxic, and lead-containing wastewater cannot be degraded by microorganisms when it enters the environment. It can only be transformed, dispersed and enriched by morphology, and is transmitted along biological chain through the skin and digestive tract. Respiratory tract enters the human body and a variety of organs affinity savings. But lead is a widely distributed element in nature and is often used as a raw material for manufacturing. If the waste water containing lead is not disposed properly and safely, it will bring great harm to the environment. Therefore, it is necessary to find a safe, reliable and economical and effective way to treat waste water containing lead. Steel slag is a kind of slag discharged in steelmaking process. It is divided into converter slag, flat slag and electric slag. It has been used as solid waste disposal for a long time. In this experiment, the composition and microstructure of the converter slag were observed by means of XRF,XRD,SEM,BET and other testing methods. The results show that the steel slag surface is rough and porous, and it has certain adsorption ability. The main chemical composition of steel slag is that CaO,SiO2; steel slag is alkaline in water and has certain chemical precipitation effect on lead ion in aqueous solution. The mineral composition of steel slag is mainly C _ 2S _ 2 C _ 3S, which is similar to Portland cement clinker and can be used as a mixed material to prepare steel slag cement. Therefore, using steel slag to treat lead-containing wastewater and to explore the feasibility of preparing steel slag cement by adsorption of lead-ion steel slag as building material. In order to improve the adsorption performance of steel slag, three modification methods, alumina modification, high temperature activation and acid leaching, were used to improve the adsorption properties of steel slag. The effect of sulfuric acid on the modification of steel slag is the best, and the optimum modification conditions are as follows: hydrogen ion concentration 0.32 mol 路L ~ (-1). The operation conditions of modified steel slag for treatment of high concentration lead-containing wastewater were optimized by static experiment. The results show that the addition amount of steel slag, reaction time and reaction temperature have great influence on the adsorption effect. The optimum addition ratio of lead ion to steel slag is only 1: 6, the adsorption equilibrium is reached at 200min, and the optimum reaction temperature is 25 鈩，

本文編號(hào)：2335153