Effects of advanced oxidation on green sand properties via iron casting into green sand molds

The effects of advanced oxidation (AO) processing on the properties of green sand were studied via pouring cast iron into green sand molds. Upon cooling, the green sand molds were autopsied at various distances from the metal-sand interface. Autopsy green sand samples collected from a mold that incorporated AO water were characterized and compared to controlled samples collected from a similar autopsied mold made with conventional tap water (TAP). It was found that the AO processing removed a coating of coal pyrolysis products from the clay surface that typically accumulated on the clay surface. As a result, the AO-conditioned green sand retained 10-15% more active clay as measured bythe standard ultrasonic methylene blue titration than did the TAP-conditioned green sand. The AO processing also nearly doubled the generation of activated carbon from the normalized amount of coal composition of the green sand during the casting process. The AO-enhanced activated carbon generation and the AO-incurred clay surface cleaning provided the AO-conditioned green sand with higher normalized pore volume, and thus higher normalized m-xylene adsorption capacity, i.e., relative to before-metal-pouring conditions. Furthermore, mathematical analysis indicated that the AO-conditioned green sand better retained its important properties after pouring than did the TAP-conditioned green sand. Effectively, this meant after metal pouring, the AO-conditioned sample offered about the same net properties as the TAP-conditioned sample, even though the AO-conditioned sample contained less clay and coal before metal pouring. These results conformed to the full-scale foundry empirical finding that when AO is used, foundries need less makeup clay and coal addition through each casting cycle, and they release less air emissions.     

Characterization of hydrocarbon emissions from green sand foundry core binders by analytical pyrolysis

Analytical pyrolysis was conducted to study a relative comparison of the hydrocarbon and greenhouse gas emissions of three foundry sand binders as follows: (a) conventional phenolic urethane resin, (b) biodiesel phenolic urethane resin, and (c) collagen-based binder. These binders are used in the metal casting industry for making cores that are used to create internal cavities within castings. In this study, the core samples were flash pyrolyzed in a Curie-point pyrolyzer at 920 degrees C with a heating rate of about 3000 degrees C/sec. This simulated some key features of the fast heating conditions that the core binders would experience at the metal-core interface when molten metal is poured into green sand molds. The core samples were also pyrolyzed in a thermogravimetric analyzer (TGA) from ambient temperature to 1000 degrees C with a heating rate of 30 degrees C/min, and this simulated key features of the slow heating conditions that the core binders would experience at distances that are further away from the metal-core interface during casting cooling. Hydrocarbon emissions from flash pyrolysis were analyzed with a gas chromatography-flame ionization detector, while hydrocarbon and greenhouse gas (CO and CO2) emissions from TGA pyrolysis were monitored with mass spectrometry. The prominent hazardous air pollutant emissions during pyrolysis of the three binders were phenol, cresols, benzene, and toluene for the conventional phenolic urethane resin and biodiesel resin, and they were benzene and toluene for the collagen-based binder. It was also found that volatile organic compound and polycyclic aromatic hydrocarbon emissions considerably decreased in order from conventional phenolic urethane resin to biodiesel resin to collagen-based binder. These results have shown some similarity with those for stack emission testing conducted at demonstration scale and/or full-scale foundries, and the similar trends in the two sets of results offered promise that bench-scale analytical pyrolysis techniques could be a useful screening tool for the foundries to compare the relative emissions of alternative core binders and to choose proper materials in order to comply with air-emission regulations.     

Study of the interaction of Ni2+ and Cs+ on MX-80 bentonite; effect of compaction using the "capillary method"

The goal of the paper is to assess the applicability of sorption models to describe the retention of contaminants on clay materials, both in dispersed and compacted states. A batch method is used to characterize the sorption equilibria between Cs, Ni, and MX-80 bentonite for solid-to-liquid ratios varying from 0.5 to 4200 kg/m3. For compacted bentonite (dry density of 1100 kg/m3), a new method is presented where the material compaction is performed in PEEK capillaries. Sorption edges and isotherms were measured in the presence of a synthetic groundwater. A model considering cation exchange reactions with interlayer cations and surface complexation reactions with edge sites was used for the dispersed state. Montmorillonite was shown to be the dominant interacting phase in MX-80 bentonite. The applicability of the model to compacted bentonite was tested. The results indicate that under conditions where the cation exchange mechanism is dominant, there is no difference between the dispersed and compacted states. For the degree of compaction studied, all exchange sites are available for sorption. For Ni, when surface complexation is the dominant sorption mechanism, a decrease of the Kd values by a factor of about 3 was observed (pH 7-8, trace concentrations). This could be explained quantitatively by a diminution of the conditional interaction constant between Ni and the edge surface site in the compacted state. One consequence of this decrease is that the contribution of the organic matter content of MX-80 bentonite to the total sorption becomes significant.     

黏土-膨润土基铁炭陶粒填料的制备与应用

以黏土、膨润土为主要原料,采用高温焙烧法制备出新型水处理陶粒填料,对填料的配方和制备工艺进行研究。结果表明,填料最佳性能条件为:铁炭质量比为4∶1,原料质量比黏土∶膨润土为1∶1,黏土、膨润土和助剂量占总填料80%,羧甲基纤维素钠和硫酸铵分别占总填料1%。焙烧温度500℃,焙烧时间30min,在此工艺下填料的压溃强度为52N,孔隙率为28.9%。采用铁-炭微电解法处理造纸二沉池出水,反应70min,其COD Cr去除率达71%。     

Effects of feeding bentonite clay upon ochratoxin A–induced immunosuppression in broiler chicks

A presence of mycotoxins in feed is one of the most alarming issues in the poultry feed industry. Ochratoxins, produced by several Aspergillus and Penicillium species, are important mycotoxin regarding the health status of poultry birds. Ochratoxins are further classified into to several subtypes (A, B, C, etc) depending on their chemical structures, but ochratoxin A (OTA) is considered the most important and toxic. Bentonite clay, belonging to phyllosilicates and formed from weathering of volcanic ashes, has adsorbent ability for several mycotoxins. The present study was designed to study the effects of bentonite clay upon OTA-induced immunosuppression in broiler chicks. For this, 480 day-old broiler chicks were procured from a local hatchery and then different combinations of OTA (0.15, 0.3, or 1.0 mg/kg) and bentonite clay (5, 10, and 20 g/kg) were incorporated into their feed. At 13, 30, and 42 days of age, parameters such as antibody responses to sheep red blood cells, in situ lymphoproliferative responses to mitogen (PHA-P), and in situ phagocytic activity (i.e., via carbon clearance) were determined respectively. The results indicated there was a significant reduction of total antibody and immunoglobulin titres, lymphoproliferative responses, and phagocytic potential in OTA-treated birds, suggesting clear immunosuppression by OTA in birds in a dose-dependent manner. These results were also significantly lower in all combination groups (OTA with bentonite clay), suggesting few to no effects of feeding bentonite clay upon OTA- induced alterations in different immune parameters.     

Evaluation of volatile hydrocarbon emission characteristics of carbonaceous additives in green sand foundries

This research studied a relative comparison of the hydrocarbon emissions during pyrolysis of four carbonaceous additives that can be used in green sand foundries. These included a highly volatile bituminous coal, anthracite, lignite, and cellulose. Analytic pyrolysis was conducted to simulate the heating conditions that the carbonaceous additives would experience during metal pouring. Specifically, the samples were flash pyrolyzed in a Curie-point pyrolyzer at 920 degrees C with a heating rate of about 3000 degrees C/sec. This simulated some key features of the fast heating conditions that the carbonaceous additives would experience at the metal-mold interface when molten metal is poured into green sand molds. The samples were also pyrolyzed in a thermogravimetric analyzer (TGA) from ambient temperature to 1000 degrees C with a heating rate of 20 degrees C/min; and this simulated key features of the slow heating conditions that the carbonaceous additives would experience within the bulk of green sand molds that is further away from the metal-mold interface. Hydrocarbon emissions from flash pyrolysis were analyzed with GC-FID, while those from TGA pyrolysis were monitored with mass spectroscopy and GC-FID. The anthracite exhibited very low volatile hydrocarbons during both flash pyrolysis and TGA pyrolysis. The cellulose released less hydrocarbons than bituminous coal or lignite in TGA pyrolysis, but more hydrocarbons than those two during flash pyrolysis. This means that cellulose can release sufficient volatile hydrocarbons at the intensely heated molten metal-mold interface where they are most desired for ensuring casting quality, but much less within the bulk of the mold where they are undesirable. This characteristic of cellulose offers an important opportunity for green sand foundries to diminish their hazardous air pollutant (HAP) emissions.     

具有DPPH自由基抑制活性的蚕蛹蛋白酶解液脱色工艺优化

利用木瓜蛋白酶水解的蚕蛹蛋白酶解液作为研究原料,根据响应面试验设计方法,以脱色率和1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除保持率作为响应面指标,得最佳脱色工艺条件为：活性白土、碱性钙基膨润土和膨润土按照质量比1∶1∶1混合为脱色剂、脱色剂用量1.9%、酶解液质量浓度9.61 mg/mL、pH 7.2、水浴温度60 ℃、振荡转速150 r/min、脱色时间1.0 h。在此条件下实验,得出DPPH自由基清除保持率84.5%、脱色率94.5%,与预测值相比误差值均小于5%,说明采用响应面试验设计方法对蚕蛹蛋白酶解液脱色体系进行优化具有较好的可靠性。最后再对脱色前后酶解液中各氨基酸含量进行比较,发现经脱色处理后酶解液中对DPPH自由基抑制有显著作用的疏水性氨基酸和芳香族氨基酸含量减少。     

甘蔗制糖造纸厂三废综合治理利用实践

本文介绍酒精废液、造纸黑液、白泥、抄纸白水、煤渣、含SO2烟气、造纸中段碱性废水等的综合治理利用实践．实践表明，酒精废液、造纸黑液、白泥、抄纸白水对环境的污染已基本解决；另外，湿式脱硫设备的脱硫率达98.0％，烟气总除尘率达99.0％，煤渣回收率达98.5％，沉淀地排水指标CODcr<100mg/L、BOD5＜50mg／L．处理1m3混合废水的费用为0．02元，开辟了一条治理造纸中段碱性废水的新路子．     

Proposals for wastewater treatment by applying flocculating activity of cross-linked poly-gamma-glutamic acid

Cross-linked poly-gamma-glutamic acid (C-L gamma-PGA) markedly purified polluted water collected from rivers and ponds by flocculation and precipitation. This effect of C-L gamma-PGA occasionally required pretreatment with polyaluminum chloride (PAC). Components of polluted water in rivers or ponds are generally thought to be clay minerals, microorganisms and chemical compounds. In this study, the flocculating activities of C-L gamma-PGA against suspensions of bentonite, diatomaceous earth, Escherichia coli and Mycrocystis aeruginosa, and against solutions of crystal violet and bisphenol A were investigated. The mode of action of C-L gamma-PGA is thought to be based on electrostatic interaction between flocculants, C-L gamma-PGA and PAC, and the surface of polluted water components, which may lead to neutralization of the zeta-potential of those components.     

无碳复写纸用白土型显色黏土的制备

从矿物特性和无碳复写纸（NCR）的显色机理出发,通过对中山膨润土制备白土型显色黏土工艺的研究,优化了酸活化制备工艺,阐述了适宜化学组成和结构对保持显色黏土的显色、稳色性能的重要性。     

枸杞果酒澄清工艺优化及其稳定性研究

通过澄清剂及澄清条件选择,利用响应面优化枸杞果酒的澄清处理条件,并通过冷处理研究枸杞果酒的稳定性。结果表明:皂土为枸杞果酒最佳澄清剂;利用皂土下胶最佳条件为:皂土添加量0.6 g/L、澄清时间9 d、澄清温度20℃,在此条件下,枸杞果酒澄清度可达91.3%;在-4℃下处理10 d可使枸杞果酒获得较好的稳定性,保持较高的澄清度;加热处理结合下胶处理,可使枸杞果酒获得较好的热稳定性;80℃杀菌20 min可使枸杞果酒达到较好的微生物稳定性。     

超声与光催化作用对大豆蛋白/TiO_2复合膜抗菌特性的影响

采用光催化/超声预处理,结合涂膜法制备大豆蛋白/TiO_2纳米复合膜,分析光催化和超声预处理以及膜中TiO_2含量对复合膜性质的影响。当TiO_2含量低于2%时,扫描电子显微镜观察发现TiO_2纳米颗粒均匀地分散在大豆蛋白基质中,从而有效地改善复合膜的机械性能,降低膜的溶胀变形程度,提高膜的热稳定性,增强复合膜的抗菌活性。荧光光谱分析、红外光谱和X-射线衍射分析证实了大豆蛋白和纳米颗粒间以氢键为主要作用力,且光催化可进一步增强TiO_2颗粒与大豆蛋白链间交联作用,因而光催化复合膜的机械性能、热稳定性和抗菌活性均高于超声复合膜。但当TiO_2含量过高(2%)会加剧TiO_2间的自聚,导致复合膜机械性能下降、溶胀变形程度增大及荧光淬灭。因此光催化大豆蛋白/TiO_2纳米复合膜有望成为新型绿色抗菌包装材料。     

Effect of alcohols on the retention mechanisms of Cd and Zn on Wyoming bentonite and illite

The effects of ethanol- and methanol-water mixtures on Zn and Cd sorption onto bentonite and illite were investigated at low initial metal concentration (< or =10(-5) M) and low ionic strength (2.5 mM Ca(NO3)2). For all cosolvent fractions, the percent coverage of Zn and Cd to clay minerals was low (<5%) and independent of the solution dielectric constant, epsilon, except for Zn at 10 microM. Cadmium sorption to bentonite and illite was independent of epsilon. Zinc sorption varied significantly between clay types, cosolvent type, and cosolvent fraction. The partitioning of Zn to bentonite increased from 0 to 10% alcohol-water fraction and decreased after 10%. The same pattern was observed for the partitioning of Zn on illite in methanol-water mixtures. In ethanol-water mixtures, Kf for Zn on illite increased continuouslyfrom 0 to 50% ethanol. The decreased partitioning and hence mobility of Zn to bentonite and illite after 10% alcohol (only in methanol-water mixtures for illite) suggests a potential environmental threat resulting from increased transport of this metal in subsurface environments where these cosolvents are present.     

微波处理对毛豆仁POD酶活的影响

比较不同微波处理条件下毛豆仁POD 酶活变化,建立微波处理功率、时间、料水比与POD 酶活的数学回归模型。通过响应面优化出最佳灭酶工艺参数：在微波功率650W、料水比2:1(g/mL)条件下处理80s,检测不到POD 酶活,且感官、营养品质较佳。结果显示：与传统热水烫漂相比,在有效钝化POD 酶活的前提下,VC 损失率下降14.02%,叶绿素损失率下降11.43%,粗脂肪和蛋白质含量无显著变化。     

聚氧化乙烯/凹凸棒土微粒助留助滤体系的研究

通过研究发现凹凸棒土能与PEO构成一种新的非离子型助留体系。当凹凸棒土用量为4%,PEO用量为0.01%时,PEO/凹凸棒土微粒助留体系有很好的助留助滤性能。该助留助滤体系对成纸的匀度没有影响,是一种微粒助留体系。凹凸棒土的添加对纸张的白度有一定的影响。并将该体系与CPAM/膨润土体系进行对比研究发现在相同的助留助滤效果的情况下,该体系比CPAM/膨润土的吨纸耗用成本低得多,是一种理想的经济实用型微粒助留体系。     

Application of sepiolite in clarification of pomegranate juice: changes on quality characteristics during process

In this study, for the first time, the function of acid‐activated sepiolite clay was evaluated for clarification of pomegranate juice. The optimum conditions of clarification process were achieved using response surface methodology based on juice turbidity as a response. After that, under optimal condition, efficiency of sepiolite, bentonite and combination of these fining agents with gelatin and kieselgel was compared for clarifying pomegranate juice. The results showed that the best conditions for juice clarification were 0.05% (w/v) clay concentration, temperature of 50 °C and time of 2 h. The results revealed that treatments of bentonite–gelatin–kieselgel and sepiolite–gelatin–kieselgel were the most active fining agents that their use led to a reduction of 99.7% in turbidity of pomegranate juice. Kinetic study for different features was performed, and the results indicated that rate of changes in turbidity, viscosity, total phenolic contents and colour with time followed first‐, first‐, zero‐ and zero‐order kinetic models, respectively.     

钼酸铵改性膨润土的制备及其对碱性蓝染料的吸附

针对印染行业废水的污染现状,以钙基膨润土为原料,钼酸铵作为改性剂,制得一种新型水处理剂钼酸铵改性土,对碱性蓝染料印染废水进行处理。经过试验研究,确定了制备的最佳条件：膨润土悬浊液配比为1∶15、钼酸铵溶液质量分数为0.2%、浸泡时间为5min、加热时间为10min。由于钼酸铵聚合体的引入改变了膨润土在水中的分散状态,增强了其对污染物的吸附和离子交换能力。处理后印染废水的脱色率可达96.53%。在此基础上通过建立等温吸附曲线,确定改性膨润土等温吸附线为典型的L-型,属于表面配位吸附。     

不同茶类加工副产物的化学成分分析

为了实现对不同茶类加工副产物的有效利用,本文研究了绿茶、乌龙茶和红茶的茶片、茶末、茶梗和大宗茶中化学成分含量,并进行比较分析。结果表明:绿茶是不发酵茶,其茶片和茶末中儿茶素含量分别为19.34%和18.52%,高于其他茶类和副产物,与绿茶大宗茶含量相近甚至高于大宗茶,茶梗中游离氨基酸和总糖含量分别为2.65%和22.85%,高于其他副产物和大宗茶;红茶为发酵茶,其茶片、茶末和茶梗中茶黄素和聚酯型儿茶素(TSs)含量较高,其中红茶茶末中茶黄素总量(TFs)、聚酯型儿茶素A(TSA)和聚酯型儿茶素B(TSB)含量最高,分别为0.96%、1.65%和0.53%;乌龙茶是半发酵茶,其加工副产物中儿茶素、TFs、TSs含量居于绿茶和红茶之间,氨基酸组分含量低于绿茶和红茶。研究表明,绿茶、乌龙茶和红茶茶片和茶末的茶多酚、水浸出物、总糖、可溶性蛋白、咖啡碱以及儿茶素和游离氨基酸组分等化学成分利用价值与大宗茶相近,甚至高于大宗茶,茶梗中总糖和游离氨基酸组分含量高,利用价值高于大宗茶,本研究明晰了不同茶类及其加工副产物的化学成分含量,可为茶叶加工副产物的进一步研究和开发利用提供基础。     

Binding waste anthracite fines with Si-containing materials as an alternative fuel for foundry cupola furnaces

An alternative fuel to replace foundry coke in cupolas was developed from waste anthracite fines. Waste anthracite fines were briquetted with Si-containing materials and treated in carbothermal (combination of heat and carbon) conditions that simulated the cupola preheat zone to form silicon carbide nanowires (SCNWs). SCNWs can provide hot crushing strengths, which are important in cupola operations. Lab-scale experiments confirmed that the redox level of the Si-source significantly affected the formation of SiC. With zerovalent silicon, SCNWs were formed within the anthracite pellets. Although amorphous Si (+4) plus anthracite formed SiC, these conditions did not transform the SiC into nanowires. Moreover, under the test conditions, SiC was not formed between crystallized Si (+4) and anthracite. In a full-scale demonstration, bricks made from anthracite fines and zerovalent silicon successfully replaced a part of the foundry coke in a full-scale cupola. In addition to saving in fuel cost, replacing coke by waste anthracite fines can reduce energy consumption and CO2 and other pollution associated with conventional coking.     

Ultrasonication and Fresh Produce (Cos lettuce) Preservation

Washing Cos lettuce in various sanitizers at different concentrations with and without ultrasonication (40 KHz) reduced the microbiological counts by 1 to 2.5 log colony‐forming units (CFU)/g immediately after washing. Ultrasonication of Cos lettuce in water, chlorinated water, peracetic acid, hydrogen peroxide, and their combinations at various temperatures (4 °C, 20 °C, 35 °C, 47 °C, and 50 °C) had no significant effects (P > 0.05) on the total or the psychrophilic counts during storage at 10 °C. The total count in Cos lettuce reached 9.74 ± 0.035 log CFU/g after ultrasonication (2 min at 50 °C) in chlorinated water (100 mg/L) and storage for 6 d at 10 °C. Extending the ultrasonication (40 kHz) of Cos lettuce for up to 20 min did not improve the bactericidal effect of ultrasonication. However, long‐time ultrasonication (20 min) caused significant (P < 0.05) damage to the quality of Cos lettuce tissues.