Treatment of black liquor from the papermaking industry by acidification and reuse

Two different kinds of black liquor from the papermaking industry were treated by acidification and reuse. The experimental parameters and conditions were discussed in detail. The experimental results indicated that the treatment process mentioned in this article is an effective process for the treatment of black liquor from the papermaking industry. By the treatment, the solid materials in black liquor are transferred into two by-products and the other components are reused or evaporated. Thus, no wastewater except some condensation water would be discharged in pulping process and the problem of oollution of black liauor would be effectively solved.     

利用造纸黑液回收电镀废液中铬的研究

本文报道了利用造纸黑液回收电镀废液中铬的方法，阐明了造纸黑液中所含有还原性物质与Ｃｒ＾６＋的反应机理；讨论了进行反应的最佳条件以及采用这一方法对废液的治理效果。     

金属系无机抗菌材料研究进展

主要介绍金属系无机抗菌材料。从材料的选择和合成方面,讨论了材料的特性和抗菌功能相结合的途径,归纳出抗菌材料的制备工艺的一般规律,为开发适合我国国情的无机抗菌材料提供思路。     

两种粉煤灰的烟气脱硫实验

采用粉煤灰(FA)和Ca(OH)2水合制得的高活性吸收剂作为二氧化硫的干法脱硫剂，重点研究了两种粉煤灰(电除尘灰和湿式水膜除尘灰)在同一配比、同一水合温度、同一水合时间下的脱硫效率，结果表明：电除尘灰比湿式水膜除尘灰脱硫效率高，并且电除尘的脱硫效率略微低于活性炭，同时介绍了粉煤灰的脱硫机理。     

A voltammetric screening method to determine ronidazole in bovine meat

Abstract

An original voltammetric screening method, employing glassy carbon electrode (GCE) with the differential-pulse voltammetry technique (DPV), has been developed to determine residues of the anti-parasitic agent Ronidazole (RNZ) in bovine meat. By using cyclic voltammetry (CV), it has been demonstrated that an irreversible cathodic process occurs at approximately ?0.740?V (vs. Ag|AgCl, KCl 3?mol L^?1) in a 0.100?mol L^?1 phosphate buffer at pH 6.5 as supporting electrolyte. Furthermore, the behavior of RNZ in CV indicates the occurrence of a diffusion mass transfer process to the working electrode surface. The RNZ reduction mechanism was proposed as a 6-electron transfer, similar to Metronidazole under the same pH range. Quantification of RNZ and method validation were then carried out by DPV. The relative standard deviation (RSD) were 3.21% for intraday precision of 10 consecutive repetitions and 6.78% for interday precision after five analysis. Limits of detection and quantification were also obtained, and the values were 0.107 and 0.358?mg kg^?1, respectively. The recovery percentage for three different concentrations of RNZ in the bovine meat matrix ranged between 98.1% and 100.3%. The method proved to be efficient for screening RNZ in bovine meat.     

复合药剂对不同类型重金属污染土壤的固化修复

为了考察复合药剂对Pb、Hg、Cr、Cd、Zn、Cu和Ni污染土样的固化修复效果,以重污染企业用地、冶炼厂河道底泥和自配土壤为污染土样进行试验,试验中的普适复合药剂主要为含磷酸盐沉淀剂、黏土和水泥,视情况辅以无机还原助剂和有机络合助剂。在普适药剂(相对原土样的质量分数15%)、还原剂(5%)和有机助剂(2%)的组配下,处理后的重金属浸出质量浓度低于GB 18598—2001标准值。普适药剂对Pb、Cd、Zn、Cu、Ni的固化有效,磷酸盐是促成Pb固化的关键成分,黏土和水泥分别起到吸附固定和物理包封的作用。无机助剂中的还原/络合性成分和硫化物分别对Cr(VI)和Hg的固化有明显的促进作用。对于Pb、Cd、Zn、Cu复合污染土壤的修复,分析了重金属浸出质量浓度随普适药剂投加量变化的特征曲线,结果表明,Pb比Cu的曲线斜率更大,表明Pb的固化效率更高;Cd和Zn具有相似的曲线形状,推测二者具有类似的固化机理。     

显色环保型融雪剂的研制

研究开发显色环保型融雪剂,添加了缓蚀剂和对植物生长有益的植物钙剂,能够减少对金属、路面、植物等的腐蚀,并根据融雪剂颜色的变化,控制融雪剂用量。试验结果表明：显色环保型融雪剂使用量在20 g以下时,融冰量随着融冰时间的增加而增加,融冰量在融冰时间80分钟左右达到最大值,80分钟以后融冰量随着融冰时间的增加而减少,最佳融冰比为1：5（1份融雪剂：5份冰）。三种融雪剂的融冰效果为：自制融雪剂〉市售融雪剂〉氯化钠,且自制融雪剂对金属的腐蚀性小,对植物的生长基本没有影响。     

含铬电镀废水的资源化处理

针对电镀厂产生的高浓度含铬废水,研究了硫化钠还原沉淀法回收电镀废水中的铬的可能性。讨论了pH、投药量、反应时间和搅拌速率等变量对铬回收效果的影响。结果表明:在pH1.6,工业硫化钠(60%)投加量为4.0g/L废水,搅拌速率170r/min和反应时间t=90min的条件下能够将原水中初始浓度为533.1mg/L的三价铬C(rⅢ)和530.0mg/L的六价铬[C(rⅥ)]分别降到42.9mg/L和0.01mg/L。此时铬渣中三氧化二铬(Cr2O3)含量为29.5%,满足回用要求。接下来,为了进一步去除残余的三价铬C(rⅢ),利用正交试验设计讨论了重金属捕集剂(FZ)对其去除的最佳条件。在上述条件下出水中总铬(TCr)浓度最终降到0.94mg/L。     

Leaching of arsenic from coal fly ashes 2. Arsenic pre‐leaching with sodium gluconate solution

The present study deals with the development of an efficient and reliable process for safe disposal of coal fly ash to remove arsenic that has been found to be the most easily leachable and hazardous heavy metal in coal fly ash. Pre‐leaching of fly ash prior to disposal by a natural chelating agent, sodium gluconate (SG), was proposed and studied. Several operational factors influencing arsenic leachability, such as concentration of SG solution, liquid to solid ratio, pH, length of leaching time and leaching temperature were examined. Arsenic was found to leach out substantially with SG, but almost no further release was observed from the ash pre‐leached by SG. After the pre‐leaching treatment, the desirable high buffering capacity of the ash was well sustained. SG solution was effectively regenerated by activated alumina adsorption so that it could be successfully reused for multiple leaching/adsorption cycles.     

Experimental study on agitated drying characteristics of sewage sludge under the effects of different additive age

Drying experiments of dewatered sewage sludge (DSS) were conducted on a agitated paddle dryer, and the effects of additive agents, i.e., CaO, pulverized coal (PC), heavy oil (HO), and dried sludge ("DS" through back mixing) on the agitated drying characteristics of DSS were investigated. The results indicated that CaO can significantly increase the drying rate of DSS. The drying rate at CaO/DSS (mass ratio) = 1/100 was 135% higher than that of CaO/DSS = 0. Pulverized coal has no obvious effect on drying rate, but the increase of PC/DSS can promote breaking up of sludge lump. Heavy oil was found to be slightly effective in improving the drying rate of DSS in the examined experimental range of HO/DSS = 0-1/20. It is also found thatHOcan reduce the torque of the dryer shaft, due to its lubrication effect. Back mixing of DS was found to be effective in alleviating the unfavorable effect of the lumpy phase by improving the mixing effect of the paddle dryer. There was a marked increase of drying rate with an increase of the DS/DSS in the experimental range of DS/DSS = 0-1/3.