Removal of Lead Ions from Aqueous Solutions by Different Types of Industrial Waste Materials: Equilibrium and Kinetic Studies

Abstract

A comparative study of the adsorbents prepared from several industrial wastes for the removal of Pb²⁺ has been carried out. Fertilizer industry waste viz. carbon slurry and steel plant wastes viz. blast furnace (B.F.) slag, dust, and sludge were investigated as low‐cost adsorbents after proper treatment in the present study. The adsorption of Pb²⁺ on different adsorbents has been found in the order: B.F. sludge>B.F. dust>B.F. slag>carbonaceous adsorbent. The least adsorption of Pb²⁺ on carbonaceous adsorbent even having high porosity and consequently greater surface area as compared to other three adsorbents, indicates that surface area and porosity are not important factors for Pb²⁺ removal from aqueous solutions. The adsorption of Pb²⁺ has been studied as a function of contact time, concentration, and temperature. The adsorption has been found to be exothermic, and the data conform to the Langmuir equation. The kinetic results reveal that the present adsorption system follows Lagergren's first order rate equation. Since all three waste products from the steel industry show higher potential to remove lead from water, therefore, it is suggested that these metallurgical wastes can be fruitfully employed as low‐cost adsorbents for effluent treatment containing toxic metal ions.     

利用含钴工业废料研制黑色陶瓷颜料

本从Cr-Fe-Mn-Cu-Co系统进行研究,对含钻工业废料添加Cr2O3、CuO等物质进行试验。通过配方优化、调整,最终获得符合工业生产的黑色颜料,随后对坯釉适应性又做了补充试验。     

Removal of Phenolic Pollutants from Water Utilizing Mangifera indica (Mango) Seed Waste and Cement Fixation

Abstract

A process for the removal of two chlorophenols (2-chlorophenol and 2,4-dichlorophenol) from water using surface modified mango seed waste by adsorption process followed by cement fixation of the phenols-laden adsorbent is investigated. The two main objectives of this study were to develop efficient adsorbent utilizing mango seed waste by physiochemical activation and to an environmentally-friendly disposal of phenols-laden adsorbent into cement by a fixation process. The results of the present study reveal that the modified mango seed adsorbent showed an efficient adsorption potential for chlorophenols removal from water. The maximum adsorption potential of modified mango seed adsorbent for 2-chlorophenol and 2,4-dichlorophenol was 40.6 and 72.3 mg g^?1, respectively at 25°C. Adsorption kinetic data of chlorophenols adsorption on mango seed adsorbent could be described more favorably by a pseudo-second-order kinetic model. After the adsorption studies, the phenol-laden adsorbent was immobilized in cement for its ultimate disposal. Leachates from the fixed phenols-laden adsorbent exhibit phenols concentrations lower than the drinking water standards. Results from this study suggest the potential utility of agricultural wastes as one of the most promising activated carbon precursors for phenols removal from water and wastewater and the safe disposal of phenol-laden adsorbent into cement by fixation process.     

Removal of Chromium(VI) and Chromium(III) from Aqueous Solution by Grainless Stalk of Corn

Abstract

Grainless stalk of corn (GLSC) was tested for removal of Cr(VI) and Cr(III) from aqueous solution at different pH, contact time, temperature, and chromium/adsorbent ratio. The results show that the optimum pH for removal of Cr(VI) is 0.84, while the optimum pH for removal of Cr(III) is 4.6. The adsorption processes of both Cr(VI) and Cr(III) onto GLSC were found to follow first-order kinetics. Values of k _ads of 0.037 and 0.018 min^?1 were obtained for Cr(VI) and Cr(III), respectively. The adsorption capacity of GLSC was calculated from the Langmuir isotherm as 7.1 mg g^?1 at pH 0.84 for Cr(VI), and as 7.3 mg g^?1 at pH 4.6 for Cr(III), at 20°C. At the optimum pH for Cr(VI) removal, Cr(VI) reduces to Cr(III). EPR spectroscopy shows the presence of Cr(V) + Cr(III)-bound-GLSC at short contact times and adsorbed Cr(III) as the final oxidation state of Cr(VI)-treated GLSC. The results indicate that, at pH ≈ 1, GLSC can completely remove Cr(VI) from aqueous solution through an adsorption-coupled reduction mechanism to yield adsorbed Cr(III) and the less toxic aqueous Cr(III), which can be further removed at pH 4.6.     

利用钠活化膨润土去除水溶液中的Ni和Co

室温环境（22±1℃）下研究了不同实验条件下钠活化膨润土去除水溶液中Ni2＋和Co2＋的能力。所研究的参数为固液比及其溶液阳离子初始浓度,实验包括了膨润土在Ni2＋、Co2＋不同浓度溶液中分别对Ni和Co的反应。结果表明,膨润土很容易吸附2种金属,但是对Ni表现出了更高的吸附性。对溶液中2种金属离子吸附的协同或抑制作用取决于离子初始浓度,当重金属初始浓度超过膨润土对阳离子交换吸附能力（CEC）时出现过吸附。     

Biosorption Potential of Coco-Peat in the Removal of Methylene Blue from Aqueous Solutions

An agro-waste, coco-peat was investigated as a biosorbent for methylene blue from aqueous solutions. The practicability of biosorption process was examined by varying the experimental parameters such as pH (2-9), initial concentration (50-200 mg/L), contact time (2-240 min), and temperature (298-318 K). Maximum uptake of 212.8 mg/g was observed at pH 8 based on the Langmuir model. Among different isotherm models examined (Langmuir, Freundlich, Redlich-Peterson, and Sips), the Redlich-Peterson model described the experimental isotherms well. Coco-peat was characterized using the Fourier Transform Infrared Spectroscopy and their morphology was analyzed using scanning electron microscopy.     

利用天然浓缩丹宁合成新型凝胶吸附剂通过表面沉淀去除水溶液中铅

Lead has caused serious environmental pollution due to its toxicity, accumulation in food chains and persistence in nature. In this paper, removal of lead from aqueous solutions is investigated using a novel gel adsorbent synthesized from natural condensed tannin. The novel adsorbent performs in aqueous solutions as a weak base with valid basic groups of 1.2mmol·g-1 tannin gel particles and therefore results in the elevation of pH value of aqueous solutions. Even when initial pH is 3.6, final pH at equilibrium can climb up to 6.5 that is above the pH value for Pb(OH)2 precipitation formation and then lead can be removed from wastewater by this so-called surface precipitation. The adsorption isotherm can be expressed by the Langmuir equation and the maximum capacity for adsorption of Pb is up to 92 mg·g-1 (based on dry adsorbent) when initial pH value is 3.6. Hence, the adsorbent does offer favorable properties in lead removal with respect to its high adsorption capacity at low initial pH value, which     

Modeling Ion-Exchange for Cesium Removal from Alkaline Radioactive Waste Solutions

Abstract

The performance of spherical Resorcinol-Formaldehyde ion-exchange resin for treatment of radioactive waste solutions is investigated through computer modeling. Results show that ion-exchange is an efficient method for cesium removal from highly alkaline radioactive waste solutions. On average, two 1300 liter columns operating in series are able to treat 690,000 liters of waste with an initial cesium concentration of 0.09 mM in 11 days achieving a decontamination factor of over 50,000. The study investigated the sensitivity of ion-exchange column performance to variations in flow, temperature, and column dimensions. Modeling results can be used to optimize the design of the ion exchange system.     

工业固体废物吸附除磷影响因素的探讨

在对国内外相关文献资料分析的基础上,综述了不同工业固体废物吸附除磷研究的现状,探讨了工业固体废物对磷吸附量的影响因素,并对工业固体废物应用于工程实践方面进行了展望,旨在为进一步开发工业固体废物高效除磷材料提供新思路。     

利用酵母降低阿维菌素高浓废水COD的研究

在阿维菌素的生产过程中,过滤工序产生大量发酵废液,废液中残留的阿维菌素会对废液生物处理产生严重抑制作用。首先从阿维菌素废液中筛选得到HEUST-BS-01酵母菌株,然后对以阿维菌素废液为培养基的摇瓶发酵条件进行了研究,之后进行了2 L小型发酵罐培养、逐步升级培养直至在120 t大罐中进行了80 t废水的试验。大罐试验结果表明,每吨发酵液可产酵母粉482 kg,COD约降低40%。发酵可于开放环境下进行,不需要搅拌,大大降低发酵成本。经检测,得到的酵母单细胞蛋白含有蛋白质40.02%、灰分5.18%、水分8.12%,符合国家标准要求。本研究具有显著的社会效益、环境效益和经济效益。     

Adsorptive Removal of Co and Sr Ions from Aqueous Solution by Synthetic Hydroxyapatite Nanoparticles

Hydroxyapatite nanoparticles were synthesized by using the precipitation method with simulated body fluid solution and applied for adsorption of Co²⁺ and Sr²⁺ in aqueous solution. The single- and bi-solute adsorption experiments were performed to evaluate the maximum adsorption capacity of hydroxyapatite nanoparticles for Co²⁺ and Sr²⁺, the effect of temperature and pH, and the influence of simultaneous presence of other competing metal ion in a binary system. The synthesized hydroxyapatite nanoparticles had high adsorption capacity for Co²⁺ and Sr²⁺ due to a high specific surface area. The maximum adsorption capacity and binding energy of Co²⁺ were higher than those of Sr²⁺ in single-solute adsorption. The extended Langmuir model was fitted well for bi-solute competitive adsorption of Co²⁺ and Sr²⁺ onto the hydroxyapatite nanoparticles. Thermodynamic analysis showed that adsorption occurred spontaneously for both metals and was endothermic for Co²⁺, but exothermic for Sr²⁺.     

工业污水回用工艺技术方案选择

通过对目前国内石化行业几种污水回用技术进行对比、分析,并根据中国石油新疆独山子石化分公司乙烯厂为期4个月的污水回用中试结果,最终选择了双膜法处理方案。介绍了所选择的污水回用技术方案的简易流程及预计效益。     

Adsorptive Removal of Pb(II) and Cu(II) Ions from Aqueous Solutions by Cross-Linked Chitosan-Polyphosphate-Epichlorohydrin Beads

In this study, the cross-linked chitosan-polyphosphate-epichlorohydrin (CCPE) beads were prepared by cross-linking chitosan with both polyphosphate and epichlorohydrin and used as bioadsorbent for the removal of Pb(II) and Cu(II) ions from aqueous solutions. The effects of the dosage of CCPE beads, solution pH, initial metal ion concentration, contact time, and temperature were investigated. Then, three important factors were selected to optimize the removal processes by the orthogonal test. The results show that CCPE beads can effectively remove the Pb(II) and Cu(II) ions from aqueous solutions, and the maximum percentage removals for Pb(II) and Cu(II) ions are 99.7% and 91.2%, respectively. The data show also that the removal processes for both Pb(II) and Cu(II) ions fit best the pseudo-second order kinetic model. Moreover, the decrease of the adsorption ability of CCPE beads is less than 10% after reuse for 9 times, which suggests that CCPE beads have good reusability.     

气浮除油在焦油车间废水处理中的应用

介绍了FJL-40型气浮除油机结构、除油原理和气浮除油的影响因素。对焦油车间废水的除油试验表明。该除油机具有除油效率高、操作简单和生产成本低等优点，值得推广应用。     

聚乙烯亚胺辅助超滤法处理含锶含钴废水

研究了聚乙烯亚胺（PEI）辅助超滤处理含重金属离子锶（sr2＋）和钴（Coz＋）的废水。重点考察了PEI与重金属离子的质量浓度比（P／M）,溶液pH以及离子强度对sr^2＋和Co“截留率的影响。结果显示PEI去除sr^2＋和Co^2＋的最适pH为5和9,去除两种金属离子的最佳P／M值均为10。在最佳P／M值和最适pH时,对锶和钴的截留率分别为59％和100％。试验结果表明使用PEI辅助可以大大提高超滤膜对重金属废水中Sr^2＋和C0^2＋（尤其是con）的去除效率。     

Adsorptive Removal of 2-Nitrophenol and 2-Chlorophenol by Cross-Linked Algae from Aqueous Solutions

Abstract

The use of the cross-linked marine seaweeds Lessonia nigrescens Bory and Macrocystis integrifolia Bory to remove 2-nitrophenol and 2-chlorophenol from aqueous solutions at room temperature was investigated. The effect of the initial pH, adsorbent dose, and initial concentration of the pollutant were evaluated in batch experiments. The mathematical adsorption models of Langmuir and Freundlich show a mixed adsorptive mechanism of both phenolic compounds by the algae. The calculated parameters demonstrate a high adsorbent to pollutant affinity ratio, indicating the potential effectiveness of these marine seaweeds in the removal of these phenolic compounds from diluted aqueous solutions.     

Phenol Removal from Aqueous Solutions by a Novel Industrial Solvent

This article presents a useful method for the removal of phenolic contaminant from water and wastewaters by a novel industrial solvent using liquid-liquid extraction method. For this purpose, a paraffinic-based solvent (Iso-kerosene) was used. The selected ranges for the parameters were 20–50°C for temperature, 100–500 (mg/L) for phenol concentration, and, 1–6 for aqueous feed pH. In each experiment run, the percentage of extraction was calculated. The percentage of extraction was measured to be in the range of 15–70%. The best percentage of extraction was obtained under the conditions of 100 (mg/L), 50°C, and pH = 6. The results showed that the extraction efficiencies are extremely sensitive to temperature. The ANOVA analysis of the results showed the degree of importance of the parameters and their contribution in the final extraction efficiency as extraction temperature, pH of the feed solution, and feed concentration, with a contribution of 73.47, 24.15, and 0.7, respectively. The contribution of experimental error and F ratios also demonstrated the accuracy of the results.     

有毒有机化工废水的治理与资源化

该项目在研制具有不同极性且比表面积高、吸附容量大、机械强度好、纳米孔密集,以及孔径与被吸附物质分子直径相匹配的系列超高交联吸附树脂的基础上,成功地开发出连续式树脂吸附-脱附工艺,实现了此类废水的有效治理,并成功的实现了工业化。该项技术具有适用范围宽、吸附效率高、脱附再生容易、固液易于分离、树脂吸附性能稳定且寿命长、操作简便、能耗低等特点。     

Simultaneous Recovery of Nickel and Cobalt from Aqueous Solutions using Complexation-Ultrafiltration Process

Simultaneous recovery of nickel and cobalt from aqueous solutions by complexation-ultrafiltration process with polyethylenimine (PEI) was studied. Experiments were performed as a function of polymer/metal ratio (P/M), solution pH, and ionic strength. Effects of concentration time on metal rejection and membrane flux were also studied. At optimum experimental conditions of pH 6.0 and P/M 5.0, the nickel removal efficiency reaches at 99.9% and cobalt removal efficiency goes to 96.4%. Both nickel and cobalt removal efficiencies decreased as the adding salt concentration increases. During 12 h of the ultrafiltration process, the decline of membrane flux was less than 16% and the removal efficiencies for both nickel and cobalt were kept almost constant. Diafiltration was further performed to regenerate PEI. The removal efficiencies for both metals using recycled PEI were found to be close to those with the original PEI. Results from the two-step process of complexation-UF and decomplexation-UF separation showed that it could be a promising method for simultaneous recovery of nickel and cobalt from aqueous solutions.     

含铜蚀刻废液生产碱式氯化铜废水的脱氨氮处理

本论文针对利用含铜蚀刻废液生产碱式氯化铜（TBCC）豹过程中产生高氨氮废水的问题,提出了废水的脱氨氮处理工艺——蒸氨,并针对蒸氨设备进行了具体参数的调试,提出了找出了最佳的生产条件：蒸氨进料的pH不能低于11．3（25℃）,处理量为3．5m3／h,蒸汽开度为88％。