Study on Deep Treatment of Phosphorus in Secondary Effluent by Coal Fly Ash

In order to explore the best adsorbent and new way of removing phosphorus, this trial uses coal fly ash with PFS and alkali modified coal fly ash to deal with phosphorus in Secondary Effluent. The results: using the coal fly ash with PFS to deal with the model wastewater of 3mg/L, the removing rate can reach 72%. The combination of coal fly ash and PFS can make adsorption and coagulation express synergistic effect, and strengthen the Coagulation Effect. Using the NaOH modified coal fly ash to deal with phosphorus in Secondary Effluent, when dosage is 8g and stirs for 5min in 30r/min, the removing rate can reach 90%. After modified, coal fly ash expresses the adsorption, at the same time coal fly ash and phosphoric acid root ion settles, and strengths the treatment effect. Comparative analysis of the two methods, the NaOH modified coal fly ash can remove phosphorus effective and realize spate separation. This method can reduce the cost, and the metod is easy. It is worth to extensive application.     

Properties and Disposal of Municipal Solid Waste Incineration Fly Ash

Incineration has been used to dispose municipal solid waste(MSW) in the world.Attention is paid to the secondary pollution from municipal solid waste incineration(MSWI).Especially the safe and effective disposal of MSWI fly ash becomes an environmental and social problem which should be urgently resolved.The paper focuseds on the properties of MSW fly ash.The different kinds of technology of MSW fly ash are analysed in details.The main disposals of MSWI fly ash are filling,solidification and stabilization,and distilling heavy metals.The innocuous disposal of MSW fly ash which is compatible in China is impoldering advanced incinerator controlling the MSW and research effective and inexpensive stabilization chemicals and effective technique of distilling heavy metals to reduce the secondary pollution caused by the heavy metal of MSWI fly ash.     

含锰废水的粉煤灰处理

为解决含锰工业废水对环境、土壤及生物带来的危害,研究采用热电厂废弃物粉煤灰作为吸附剂,希望能找到最佳吸附条件,同时为粉煤灰的综合利用提供更多机会;采用EDTA滴定法,对含锰废液进行了吸附研究,模拟测定了影响粉煤灰吸附特性的几种因素:重金属离子浓度、吸附时间、粉煤灰颗粒度以及待吸附液的pH等;结果表明:在其它条件相同的情况下,随着废液Mn2 浓度的增大,去除率逐渐降低;在吸附中60min为最佳震荡时间;随着粉煤灰粒度的减小,去除率增加;pH值应控制在中性偏碱性(pH值约为8.0最好)范围;可见,采用粉煤灰吸附含锰工业废水在适当工艺条件下可以有很好的处理效果,这种方法较简便,成本低廉,能达到以废治废的目的。     

粉煤灰治理污染土壤的染料废水之效果初报

实验测定了粉煤灰对酸性金黄G染料废水中酸性金黄G染料的吸附效能。研究了加灰量,pH值及活化处理温度对粉煤灰吸附效能的影响。结果表明：粉煤灰对酸性金黄G染料有极明显的吸附效能,可具有极好的以废治废效果;随着粉煤灰的加入,染料去除率大幅度提高,对于染料浓度低于50mg/L的溶液,去除率可达到100%;吸附pH值范围为5~6.5,活化温度为300℃时,粉煤灰的吸附能力最强。     

Using Garbage Incinerator in Recycling Disposal of Fly Ash Technology Research

The technology of incinerator fly ash as the main material and the core carbonaceous reducing agent, and the necessary absorption of chlorine and catalyst made of composite pellets, Into the garbage incineration furnace temperature reduction decomposition of dioxin, heavy metal forming glassy slag. The fly ash harmless treatment, fly ash in the incineration plant in their complete closed circulation waste disposal to achieve, Provides the optimum technical route for the treatment of MSW fly ash.     

Technology of Mixing High Property Concrete with Large Dosage Fly Ash

Being the largest mass of man-maded material, concrete demands much to resource and energy as well as affects much to environment. Whether concrete can be the dominating constructive material, the key is whether it can become green material and protect the environment at the same time. The important approach of developing is using industrial castoff largely in concrete. The tests note, that high performance concrete used of large mass of fly ash is doable. By grinding fly ash and adding high-efficient water reducer, when the dosage of cement clinker is only 25% and the dosage of fly ash is 70%, concrete with a good workability that 3 day and 28 day strength are bigger than 20 MPa and 50 MPa respectively can be achieved, which later strength develop very well. The large mass of fly ash concrete can utilize fly ash largely and reduce the dosage of clinker, that is very advantageous to protect environmental.     

冻融环境下钢筋与粉煤灰混凝土的粘结性能

通过对内贴应变片钢筋的直接拔出试验,分析冻融作用下粉煤灰掺量对钢筋与粉煤灰混凝土间粘结性能的影响,得出冻融循环作用对钢筋与粉煤灰混凝土之间粘结性能的影响规律。试验结果表明：钢筋与粉煤灰混凝土的粘结强度随粉煤灰掺量的增加而降低;当粉煤灰掺量一定时,随着冻融循环次数的增加,混凝土强度有所下降,钢筋与粉煤灰混凝土间极限粘结强度降低;当粉煤灰掺量较大,达到40%时,随冻融次数的增加,钢筋粉煤灰混凝土试件极限粘结强度的下降幅度明显减缓,极限粘结强度对应的滑移量增大。表明掺入较多粉煤灰可使试件的冻融损伤现象得到缓解,冻融环境下钢筋混凝土的粘结性能得到提高。     

粉煤灰对高强混凝土收缩徐变的影响试验研究及其修正模型

粉煤灰对高强混凝土收缩徐变的影响直接关系到结构长期性能的合理确定。制作粉煤灰掺量分别为0、12%和24%的100 mm×100 mm×400 mm的C50混凝土棱柱体试件,在试验室条件下进行收缩及不同加载龄期的徐变试验,研究了粉煤灰对高强混凝土收缩徐变的影响。根据试验结果评估了目前常用的4种相关规范公式对高强混凝土收缩徐变的适用性,并引入粉煤灰影响系数以综合反映粉煤灰掺量和加载龄期对高强混凝土收缩徐变的影响,根据试验结果和现有研究成果提出了其修正模型。分析结果表明,JTG D 62和GL 2000推荐的收缩徐变预测模式与基准试件实测结果较为吻合,验证结论亦说明所引入的粉煤灰影响系数可应用于掺粉煤灰高强混凝土的收缩徐变预测。     

含钴废水的粉煤灰处理效果初报

为解决含钴工业废水的污染问题，实验以热电厂废弃物粉煤灰为吸附剂，采用EDTA滴定法，对含钴废液进行了吸附研究。模拟测定了影响粉煤灰吸附特性的几种因素，即吸附时间、待吸附液pH值、温度、加灰量以及振动速度等，并分析了粉煤灰处理废水的机理。结果显示，在其它条件相同的情况下，随着吸附温度的降低，振荡速率的增加，加灰量的增加，吸附时间的适当延长，pH的升高，去除率逐渐升高。研究表明，采用粉煤灰吸附含钴工业废水，可以得到较好的处理效果，能达到以废治废的目的     

早龄期加载对粉煤灰混凝土变形及强度的影响

研究了粉煤灰掺量、加载龄期和加载应力对粉煤灰混凝土早期变形及加载后强度变化的影响。研究结果表明：随着粉煤灰掺量增加,混凝土的变形量逐渐降低,当掺量为30%时,变形量减少了33.6%;随着加载龄期提前或加载应力增大,粉煤灰混凝土的早期变形量增大,其中,加载应力的影响尤其明显,60%加载应力（60%的标准养护条件下7 d轴心抗压强度）比20%加载应力下混凝土最终变形量增加了277.2%;混凝土初始加载时间提前或加载应力增大会导致加载后粉煤灰混凝土强度下降,加载应力比加载龄期对加载后粉煤灰混凝土强度的影响更明显。     

Test Study on the Synthetic Control of Shrinkage Cracking on the Base of Cement Stabilized Crushed Rock

To optimize properties of the crushed rock is a simple and effective method to control the reflective cracking.There are some measures to reduce the shrinkage of the crushed rock,such as: decreasing water content and cement percentage,reducing surface tension of water.The test study shows that shrinkage resistance of the crushed rock base can be improved by mixing with fly ash,water reducing agent and shrinkage reducing agent each other,it will be better for the crushed rock to mix with fly ash,water reducing agent and shrinkage reducing agent proportionally.     

Sulphate Attack Resistance of the Concrete with Additives and Its Assessment

The influence of three kinds of additives: silica fume,slag and fly ash on the sulphate attack resistance of concrete were studied.The experiment results show that these three kinds of additives can improve sulphate attack resistance of the concrete and the order of their efficiency from high to low is silica fume,slag and fly ash;the development of mortar expansion value is closely related to the degree of sulphate attack resistance of the concrete;integrated assessing two concrete properties: mortar expansion value and compressive strength ratio can more exactly assess the sulphate attack resistance of the concrete.     

Research and Production of Non-Fired and Non-Steam-Cured Clinker_Free Fly Ash Bricks

A fly ash brick is developed by using fly ash-lime-sulphate system as the binding material, added with certain quantities of aggregates and moulded by press, which can yield 28-day compressive strength up to 20 MPa under normal curing conditions. The factors affecting the strength of product are analyzed.     

固化疏浚淤泥作路基材料工程特性试验研究

为了探讨粉煤灰和工业矿粉固化疏浚淤泥作路基材料的可行性,通过一系列室内实验研究了不同固化剂配比对固化淤泥击实特性、水稳定性、承载力和抗剪强度的影响。实验结果表明,不同固化剂配比下固化淤泥的最大干密度均超过1.50 g/cm³,最优含水率约为20~21%;淤泥固化处理后浸水4 d的膨胀率均不超过1.1%,水稳性大幅提升;矿粉含量越高,粉煤灰含量越低,CBR（California Bearing Ratio）值越高,土样的承载力越高,抗剪强度也越高。不同工况浸水4 d的CBR值均达到了较高的水平,工况SD10FA20MP（淤泥：粉煤灰：矿粉=7：1：2）CBR值最高,达到了34.8%,是规范中高速、一级公路路基填料要求最低CBR值的4.35倍,作路基填料使用可行。     

Influence of Cement Fineness and Components on Temperature Rise of Concrete

Adiabatic temperature rise of mass concrete is effected by many factors. Among those factors, the analysis of cement fineness and components is lacking. Influences of cement fineness, alkali content, replacement of fly ash, and gypsum content on temperature rise of concrete were investigated. The test results show that, temperature rise and temperature rise rate are improved with the increment of specific surface area of cement. When alkali content is ranging from 0.4% to 1.2%, the maximum temperature is reduced with the increment of alkali content, and the temperature-time will be extended whether too high or too low alkali content in cement. The increment of replacement of fly ash and gypsum content is good for reducing temperature rise of concrete.     

Study on Influence of Mineral Admixture on Chloride Ion Penetration and Diffusion in Concrete

In this paper, the influences of different kinds and different amount of mineral admixture to Cl-penetration and diffusion in concrete are studied. The results of experiment show that separate addition of mineral admixture (ground fly ash, slag fines, silica fume) into concrete can improve its resistance to chloride ion penetration and diffusion. Furthermore,the effect of silica fume is the best, fly ash second, and then follows slag fines. Mechanism analysis shows that the pozzolanic effect of mineral admixture improves the interface between the cement and aggregate in concrete, reduces the total porosity, makes pores more smaller, on the other hand it increases the Cl-consolidation capability of concrete with low alkaline C-S-H gel produced. So the resistance to chloride ion penetration of concrete is improved.     

Experimental Analysis on Time dependent Law of Surface Chloride Ion Concentration of Concrete

Immersion in sodium chloride solution was adopted to periodically test chloride ion concentration at the surface of concrete and regression analysis was completed.And time dependent law of surface chloride ion concentration of concrete with time was investigated.Influences of sodium chloride solution concentration, water to cement ratio and fly ash content on size and accumulation rate of surface chloride ion concentration were also analyzed.It is found that surface chloride ion concentration gradually grows with the of time increase the of time and reaches a steady state finally.With the increase of sodium chloride solution concentration, surface chloride ion concentration reaches the steady state more quickly and then increases numerically.Bigger water to cement ratio means quicker accumulation of surface chloride ion concentration and greater surface chloride ion concentration.Fly ash replacement could fasten accumulation of surface chloride ion concentration and surface chloride ion concentration increases with the increase of fly ash content.An improved model was proposed by comparison and correction of current models.     

Effects of Cement Additives on Properties of CSA Cement from MSWI

Municipal solid waste incineration fly ash (MSWI) was successfully used as raw material in sintering and preparing a calcium sulphoaluminate (CSA) cement clinker in laboratory. The effects of different types and different addition percentages of cement additives on compressive strength and hydration properties were investigated. The results showed that lime (LI) powder / slag (SL) powder was compatible in CSA cement system while the activities of fly ash(FA)/ MSWI was low. Adding these four types of cement additives in CSA cement system respectively, there were negative effects on compressive strengths of hardened cement at early age while LI/SL improved the compressive strength at later age. The performance of combined additives was better, especially, the specimens with 10%LI+10%SL, 10%LI+10%MSWI, and 5%LI+15%SL.     

Relationship Between Electrical Property and Microstructure of Mineral Admixtures-Cement Paste

The electrical properties of fly ash, slag and limestone powder-cement paste were studied by the methods of Cyclic Voltammetry and AC Impedance Spectroscopy. The results of electrical test were fitted by equivalent circuit. The correlations between electrical parameters of paste and unevaporable water content, pore structure by mercury porosimetry were compared. The results show that there is a positive relation between the unevaporable water content and the electrical resistivity of paste. If the unevaporable water content is higher, the hydration degree is higher and the electrical resistivity of paste is higher. The electrical resistivity of paste is increased with fly ash and slag, and it is unaffected with limestone powder of 5% dosage. The resistance Rs of pore solution of paste is increased with the prolongation of hydration, and the changes of resistance Rs and the electrical resistivity are unanimous. The resistance Rp and electrical capacitance C of gel are related to C-S-H content, and there is a negative relation between the resistance Rp and electrical capacitance C of gel. The complexity of pore structure of paste is increased with the prolongation of hydration. The constant phase angle exponent P by AC Impedance Spectroscopy is decreased and the value of fractal dimension by mercury porosimetry is increased.     

不同钝化剂对恩施Cd污染土壤的钝化效果研究

为解决恩施高山蔬菜土壤重金属镉(Cd)污染问题,采用盆栽试验,研究施加不同钝化剂（生物炭、羟基磷灰石、石灰粉、粉煤灰、混合有机钝化剂）对试验土壤中Cd的钝化效果及小白菜产量、品质及Cd含量的影响。结果表明,除石灰粉处理对小白菜生长抑制外,其他处理对小白菜鲜重、株高均有促进作用,且粉煤灰处理增加小白菜鲜重达109.72%。羟基磷灰石、石灰粉和混合钝化剂等3种处理分别提升土壤pH 25.18%、36.61%和28.21%。各处理对土壤脲酶、纤维素酶、蔗糖酶活性无显著性影响;生物炭、混合钝化剂处理显著提高磷酸酶活性达52.85%和69.82%,而石灰粉处理显著抑制了磷酸酶活性。5种钝化剂处理均降低了小白菜重金属Cd的含量,其中生物炭、羟基磷灰石、石灰粉、混合钝化剂均达到抑制吸收显著效果,且石灰粉最优,降低了73.80%。各处理对小白菜品质无显著性影响。生物炭和混合钝化剂处理分别降低了土壤中总Cd含量27.21%、46.98%;石灰粉和混合钝化剂处理降低了土壤中离子交换态Cd43.67%、47.35%。5种钝化剂的施用均能降低小白菜的Cd含量,其中混合钝化剂处理在不影响小白菜产量和品质的同时,增强了土壤酶活性,降低了土壤中总Cd及有效Cd（离子态、水溶态）比例。