混凝与AB法联用处理制革废水

针对制革废水SS、有机物、总Cr及色度较高的特点,采用混凝与AB法联合工艺处理。试验研究了混凝的条件和处理效果;分别研究了AB法的A、B两段HRT和有机负荷对处理效果的影响。研究结果表明:调节pH值为8.8～10.0,PAC的投加量为300～400 mg/L,混凝单元对制革废水的SS、色度、总Cr和CODCr的平均去除率分别为64.3%、69.2%、97.5%和23.5%;AB法的A段在HRT为50～55 min、DO质量浓度为0.8～1.2mg/L时,CODCr的去除率不小于48%,CODCr负荷达到15～17.8 kg/(m3.d);B段在HRT为8～10 h、DO质量浓度为2.5～3.0 mg/L时,CODCr的去除率不小于75%,CODCr负荷为0.55～0.75 kg/(m3.d)。制革废水经该工艺处理的出水达到GB 8978—1996《污水综合排放标准》的一级标准。     

Preventing skin cancer in college females: Heterogeneous effects over time.

Objectives: To evaluate the effects of an appearance-focused intervention to reduce the risk of skin cancer by decreasing indoor tanning, examine potential heterogeneity in tanning across this time, and correlate the subtypes with predictors collected at baseline. Design: Randomized controlled trial with 379 female college students measured at 6 monthly time points. Main Outcome Measure: Self-reported indoor tanning frequency. Results: The intervention was effective at decreasing tanning over the period between the fall and spring. Longitudinal latent class analysis found 3 patterns of tanners among the treatment individuals: abstainers, moderate tanners, and heavy tanners. These classes appeared in both the treatment and control conditions, and the intervention had a harm reduction effect by reducing levels of exposure within the moderate and heavy tanner classes. Participant age and self-reported tanning patterns were found to be predictive of class membership. Conclusions: This research suggests that brief intervention approaches can be effective at reducing risk for skin cancer and illustrates several ways in which these protective effects can be enhanced. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Novel Approach to Clean Tanning Technology

Traditional chrome tanning technology is still widely used today. In this technology, chrome shaving as well as chrome contained effluent in tanning and retanning processes is a big issue in the industry. Wet white tanning technology has been gaining in importance in recent years, but in general, the comprehensive performance of chrome-free tanned leather is not comparable with that of chrome tanned leather. In the present work, chrome-free tanning and chrome tanning are combined in a reversed procedure, which produces leather with chrome tanned leather quality without chrome tanned leather waste problems. In this procedure, a special amphoteric organic compound, no pickle, no salt chrome-free tanning agent TWT was used to tan delimed hides （no pickle） making wet white with shrinking temperature at 80-85 ~C. Then, new method called reversed tanning further process the wet white into chrome-tanned crust. In this reversed method, retanning, fatliquoring and coloring processes were carried out before chrome tanning. This technology eliminates chrome waste issue in tanning, shaving, post tanning processes. The chrome contained effluent is only concentrated in the last chrome tanning process. The leather made with this technology has complete conventional chrome-tanned leather quality. In this way, chrome leather quality without chrome waste problems was achieved. So, it is a new clean tanning technology.     

毛皮鞣制中不同铝鞣剂的对比研究

通过对比试验研究了三甲酸铝和明矾鞣制毛皮的优缺点。试验证明，采用三甲酸铝为鞣剂，成品革在面积得革率、单位面积重量、紧实性以及耐老化性等方面都具有优越的性能     

黑色革植-铬-铁结合鞣与染色一体化研究

基于植物丹宁与铁盐反应显色的原理,研究用栗木栲胶与铬-铁鞣剂结合鞣制,以实现黑色革鞣制与染色一体化,减少或免去用合成染料染色和铬盐用量。研究表明:当栲胶用量为5%,铬-铁鞣剂用量折合Cr_2O_3为1.5%～1.8%,Fe_2O_3为0.7%,鞣制的革呈纯黑色,收缩温度可达到100℃以上,手感丰满柔软,粒面细致,色牢度优良。     

逆转铬鞣工艺技术的研究进展

消除铬排放是制革工业持续发展迫切需要解决的关键科技问题。采用现有制革技术,铬鞣及其之后的所有水相操作工序都会排放铬,还会产生含铬皮革固体废物,这使得完全消除制革过程的铬排放几乎不可能实现。针对这一问题,本文介绍了以消除铬排放为目标的逆转铬鞣工艺技术。较系统地综述了该技术中的无铬预鞣单元、染整单元、末端铬鞣单元及含铬废水处理等单元过程的研究进展,分析了尚存在的问题和未来的研发方向。提出以“无铬预鞣单元-染整单元-末端铬鞣单元”为核心,通过对制革单元过程实施重组和耦合优化来构建逆转铬鞣工艺技术,可在保证成革品质的同时大幅削减了含铬污染物的产生,并使铬的完全回收和处理变得简单易行,为彻底解决制革工业的铬排放问题提供了参考。     

锆盐的鞣性分析及其发展前景

简单分析了制革业的发展现状与锫鞣的意义,从配位化学与鞣制化学的角度阐述了锆鞣与铬鞣的差异,提出锆盐是较好的铬盐替代品,具有很好的应用前景.     

糠醛类化合物的制备及其在鞣制中的应用

利用农业生物质资源,提取制备糠醛和5－羟甲基糠醛（5－HMF）,是绿色化学品研究开发的重要内容之一。糠醛结构中含有活泼的醛基,故很早以前就有人将其用于皮革的鞣制。本文综述了糠醛和5－羟甲基糠醛的制备方法及研究进展。总结了糠醛鞣革特点,并着重就糠醛和5－羟甲基糠醛的改性及其鞣革前景进行了分析讨论。     

铬酸铬渣生产铬鞣剂过程除铁技术研究进展

铬鞣剂被认为是目前制造轻革的重要材料,以铬酸铬渣为原料生产铬鞣剂是低成本的生产方法之一,但是以含铁的铬酸铬渣作原料生产铬鞣剂会影响铬鞣剂产品的质量。详细介绍了有机络合法、萃取法等在铬鞣剂生产中除铁的应用,从反应原理、工艺流程和除铁效果等几个方面对各种方法进行了对比,评价使用不同生产方法的技术优劣,并对低含铁铬鞣剂的应用前景做了展望。     

An eco‐efficient rationalized leather process

BACKGROUND: The leather industry is under pressure to develop environmentally efficient leather‐making processes to comply with modern pollution and discharge legislation. Conventional leather‐processing methods are known to contribute significant pollution loads in tannery wastewaters. The rationalized process described here involves a salt‐free curing, lime and sulfide‐free beamhouse process and post‐tanning followed by tanning employing a reverse leather‐processing technique. RESULTS: Scanning electron microscopy (SEM) analysis substantiated that the grain surface, fibre separation and tight packing of fibres are similar for leathers from conventional and rationalized processes. The functional performance of the leathers is found to be on par with that of conventionally processed leathers. The rationalized leather process reduces the usage and discharge of chemicals by 68% and 82%, respectively. It also enjoys the reduction in biochemical oxygen demand (BOD), chemical oxygen demand, Cl^?, SO₄^2? and total solids loads by 58%, 62%, 95%, 66% and 85%, respectively. The rationalized process also results in reduction of water consumption and discharge and energy by 37%, 37% and 38%, respectively. CONCLUSION: The rationalized process utilizes resources efficiently with reduced environmental impact without compromising leather qualities and can be seen as being eco‐efficient compared to the conventional leather process. Copyright © 2007 Society of Chemical Industry