混凝土预拌厂废浆水均化技术研究

通过合成一种新型的丙烯酸-丙烯酸羟丁酯-磺酸盐均化剂,对混凝土预拌厂废浆水进行了均化处理,并对均化后混凝土预拌厂废浆水的物理性能、使用均化后废浆水的混凝土性能进行了系统研究。结果表明,该均化剂可显著降低混凝土预拌厂废浆水的黏度,经处理后的预拌厂废浆水可100%替代清水使用,且对混凝土的工作性能、力学性能无不利影响。

预拌混凝土生产用废浆水的含固量快速测定方法研究

通过试验分析预拌混凝土废浆水的密度和含固量,推算出密度与含固量的关系式,并与烘干法进行比对,确定出一种预拌混凝土废浆水含固量快速测定方法。该方法的应用可明显缩短废浆水含固量的测定时间,提高废浆水利用率,并为废浆水在预拌混凝土绿色生产中的应用提供技术保障。

搅拌站废浆水用于生产高耐久性混凝土的实验研究

开展利用搅拌站废浆水生产高耐久性混凝土实验研究,重点分析废浆水浓度对混凝土抗压强度的影响以及人工砂中的石粉含量对混凝土电通量的作用机制,开发出以废浆水取代拌合用水,生产C30与C50高耐久性混凝土配合比优化方案。研究结果表明,废浆水用于生产高耐久性混凝土,可以实现混凝土生产企业废浆水资源化利用的目标,充分体现循环经济与清洁生产理念,具有良好的环境效益和经济效益。

混凝土废浆水对混凝土性能的影响

为有效掌握混凝土废浆水的特性,研究废浆水掺量分别为0、25%、50%、75%、100%时对水泥、混凝土性能的影响。结果表明随着废浆水掺量的增加,水泥的初凝时间与终凝时间均呈现缩短趋势,混凝土扩展度与坍落度都呈降低趋势,且混凝土工作性能损失增大,各龄期混凝土抗压强度均呈降低趋势。综合考虑将废浆水密度控制在1.05g/cm^(3)左右,通过适当提高混凝土减水剂掺量,废浆水掺量为25%时,混凝土工作性能得以改善,混凝土抗压强度影响不大,早期抗裂性能最佳。

混凝土搅拌站废浆水的回收利用

研究了不同浓度的废浆水对胶砂及混凝土性能的影响,结果表明:当浓度低于5%时,废浆水可以完全取代饮用水生产混凝土,并可用于配制C30、C35强度等级的高耐久性混凝土。

关于搅拌站废浆水回收利用技术的探讨

《四川省绿色环保搅拌站建设、管理和评价标准》(DB 51/T 104-2018)于2019年5月1日正式实施,本文同时以编制四川省地方标准《预拌混凝土废水废浆综合回收利用规程》为契机,对四川省内的20家搅拌站的废浆水回收利用情况进行调研。结果表明,所调研混凝土搅拌站基本实现了废浆水及废渣的回收再利用,进而提出了残留混凝土的砂石分离、废浆水预处理、废浆水及废渣再利用三方面实现回收利用。

砂石分离和废浆水的自动回收及其再利用技术

"砂石分离和废浆水的自动回收及其再利用"的投资和管理是通过对废弃混凝土拌合物处置过程的环境行为进行控制,减少混凝土处置过程对环境的危害。通过对废浆水与自来水对比试验,并进行有效配制,使废浆水在胶砂和混凝土中的应用性能满足现行混凝土用水标准要求。

商砼废浆水压滤后循环用于水泥粉磨生产的实践

商砼生产过程中产生的废浆水的综合循环利用一直以来是困扰商砼发展的难题,经过砂石分离机分离的废浆水通过压滤机压缩处理后,饼状废料代替部分煤矸石等混合材料用于水泥粉磨生产,既解决了商砼废料重复回收利用的问题,取得很好的环境效益;又降低了水泥粉磨生产成本,取得了良好的经济效益。实现了商砼废料全部回收循环利用技术上的创新。

混凝土废浆水对C30混凝土性能的影响

本文以7.5%浓度的混凝土废浆水为研究对象,研究了掺废浆水0%、20%、40%、60%、80%和100%对C30混凝土工作性能、抗压强度和早期抗裂性能的影响。研究表明:混凝土废浆水掺量不超过60%时,混凝土工作性能略有改善,早期抗压强度略有增加,早期抗裂性能略有降低;掺量超过60%时,工作性能略有下降,28d强度有5%下降,同时早期抗裂性能进一步降低;掺量超过80%时,混凝土工作性下降明显;早期抗裂性能下降明显。本试验条件下,C30混凝土的混凝土废浆水掺量不宜超过60%(浓度为7.5%)时,混凝土工作性能、抗压性能和早期抗裂性能满足要求。

探究搅拌站回收废浆水对水泥和混凝土性能影响

本文比较系统地进行了搅拌站废浆水的回收利用研究,首先,试验研究了废浆水溶液本身的物理化学性质,建立了密度与浓度(含固量)曲线,提高生产过程对废浆水指标的检测效率及准确性,便于指导生产;继而,研究了废浆水澄清液对水泥各项性能的影响;再次,用8%浓度混凝土废浆水为研究对象,以0%、10%、20%、30%、40%、50%和60%、70%、80%、100%取代清水对C30混凝土工作性、力学性能、抗碳化性能、早期抗裂等性能产生的影响进行了可行性试验研究。

Removal of Cr(Ⅲ) and Cr(Ⅵ) from aqueous solution by adsorption on sugarcane pulp residue

Sugarcane pulp residue （SPR）, a waste from sugar-refinery, which possesses a large surface area, can be used for removing chromium （Cr（Ⅲ） and Cr（Ⅵ）） from wastewater. In this work, the kinetics, isotherms of Cr（Ⅲ） and Cr（V[） adsorption and their removal by SPR were investigated. The results show that the removal percentages of Cr（Ⅵ） and Cr（Ⅲ） increase with increasing SPR dosage and temperature and decrease with increasing SPR particle size and the initial concentration of chromium ions. However, the influence of pH value on the Cr（Ⅵ） removal differs from that of the Cr（Ⅲ） removal. The Cr（Ⅵ） removal percentage decreases with increasing pH values, while the Cr（Ⅲ） removal percentage increases with increasing pH value. The adsorption kinetics of Cr（Ⅵ） and Cr（Ⅲ） well fits with pseudo-second-order model. Langmuir adsorption isotherm can well describe the adsorption phenomena of chromium ions with the maximum adsorption capacity of 0.567 mg/g for Cr（Ⅵ） and 3.446 mg/g for Cr（Ⅲ）. Moreover, SPR reveals higher adsorption capacity for Cr（Ⅲ） than that for Cr（Ⅵ）, which implies that SPR has more potential application for Cr（Ⅲ）-containing wastewater treatment than that for Cr（Ⅵ）-containing wastewater treatment.

Wet Oxidation of PVA-Containing Desizing Wastewater

Polyvinyl alcohol (PVA)-containing desizing wastewater was treated by various wet oxidation methods.Parameters such as reaction temperature, initial solution pH, and the dosage of H2O2 were investigated in terms of chemical oxygen demand (CODcr) and total organic carbon (TOC) removal rate. Up to 90% of the initial CODcr was removed by wet air oxidation(WAO) at 270℃ with stoichiometric oxygen supply, while at temperature of 200℃, the CODcr removal rate was found to be 80%. Similar results were obtained by Promoted WAO (PWAO) and wet peroxide oxidation(WPO) at a lower temperature of 150℃. Reaction temperature was found to have a significant effect on the oxidation performance for all the methods. Initial solution pH was observed to play a significant role in PWAO and WPO where H2O2 was employed. Comparison of WAO, CWAO(catalytic wet air oxidation), PWAO and WPO shows that the rate of CODcr removal increases in the order: WAO, CWAO, PWAO and WPO.

Kinetics of Wet Air Oxidation of Wastewater from Natural Fiber Web Desizing

This work described the application of wet air oxidation (WAO) to the treatment of desizing wastewater from natural fiber processing. A two-liter autoclave batch reactor was used for the experiments. The range of operating temperature examined was between 150 and 290℃, and partial pressure of oxygen ranged from 0.375 to 2.25 MPa standardized at 25℃. Variations in Chemical Oxygen Demand(COD) and Total Organic Carbon(TOC) were monitored during each experiment and used to assess the performance of the process. Experimental results showed that WAO can be an efficient method for the treatment of desizing wastewater. Furthermore, Catalytic Wet Air Oxidation (CWAO) was applied to reduce the reaction temperature and pressure in WAO process. A higher COD removal ratio was achieved under more mild reaction condition with the aid of CWAO. A mathematical model was also proposed to simulate the WAO process of desizing wastewater, in which three distinct kinetics steps were considered to describe the degradation of starch. The model simulations were in well agreement with the experimental data.

Cr （Ⅲ） Removal from Synthetic Waste Water by Using Water Pond Mud

The pollution of aquatic ecosystem by heavy metals has assumed serious proportions due to their toxicity and accumulative behavior. The toxicity metal is dependent on its chemical form and therefore removal of metal is more meaningful than the estimation of its concentrations. In this study, the batch experiments were carried out under 30℃ to study the effect of pH, initial Cr concentration, adsorbent dose and contact time on the removal of Cr （lII）. The maximum adsorption efficiency （99%） was observed when 1.5 g of pond mud was used for removal ofCr （Ⅲ） from test solution containing 150 mg·Cr / 100 ml. The optimal pH and contact time recorded during the study were 6 and 10.0, respectively.

Ferulic Acid in Paper Mulberry and Its Wastewater from Pulps Production

Wastewater from paper mulberry （Broussonetia papyrifera） pulps production was subjected to biological activities evaluations and phenolics characterization. The EtOAc extract was found to be the best antioxidant （IC50 = 0.4408 mg/mL） and tyrosinase inhibitor （IC50 = 1.6340 mg/mL） comparing to vitamin C （1C50 = 0.0011 mg/mL） and kojic acid （IC50 = 0.0244 mg/mL）, respectively, and the highest ferulic acid content （4.450 ±0.0077 ppm）. This fraction was further column chromatographed and antioxidant activity was archived （IC50 = 0.075 mg/mL） as well as tyrosinase inhibitory effect （IC50 = 0.042 mg/mL） in addition to ferulic acid （45.310 ± 0.0115 ppm）. Ferulic acid in paper mulberry was compared. Reflux with H2O gave the highest ferulic acid content （37.848 ± 1.2470 ppm） followed by a mixture of MeOH and H2O （2.002 ± 0.0370 ppm） and MeOH （1.185 ± 0.0320 ppm）, respectively. The reflux H2O was partitioned with EtOAc that extracted most of ferulic acid （256.678 ± 0.3760 ppm） and left less in the aqueous layer （9.408 ± 0.2820 ppm）.

Fundamental Study on a Grout Penetration Model for a HLW Repository

In both the construction and operation phases of a repository for high-level radioactive waste, it will be important to constrain groundwater inflow using grouting technology that will be effective under the high groundwater pressure conditions deep underground. In this research, a review of existing grout penetration models in Japan and foreign countries and a trial analysis are conducted with a goal of describing the gout penetration with accuracy on site. Specifically, the applicability of the model developed by Gustafson ＆ Stille to the laboratory penetration tests was studied. The results show that the calculated values from the Gustafson ＆ Stille model agree well with values of laboratory penetration tests.