对小纸厂碱回收可行性的初步评价

本文对小型造纸厂的碱回收在技术上和经济上的可行性进行了分析,作出了当前是中、小型造纸厂搞碱回收的有利时机的初步评价。     

回收PTA废料生产增塑剂

介绍了扬子石化公司ＰＴＡ生产过程中所排各种废料的分离提纯及回收利用，对难以回收的氧化残渣的分离回收和利用作了重点论述。提供了用所回收的ＴＡ和混合苯二甲本乡生产剂的工艺流程和工艺参数。     

含镍废催化剂的回收利用

介绍了从含镍废催化剂中以硝酸镍形式加收镍的方法，镍回收率为70％，硝酸镍纯度为96．6％。该工艺简单，具有较好的经济效益和环境效益。     

攀钢烧结烟气脱硫技术研究

介绍了攀钢烧结烟气的特点，SO2的来源。根据国内外烟气脱硫技术现状， 提出了攀钢烧结烟气脱硫的技术要求。     

我国化学工业的“三废”及其资源化

文章在介绍我国化学工业排放三废的严峻现状后,阐述了通过工艺改造和综合回收途径来推进三废资源化的技术对策,以及从宏观和微观上看深化三废资源化的意义和光明前景。     

Water supply development and tariffs in Tanzania: From free water policy towards cost recovery

The article describes the historical development of water tariff policy in Tanzania from the colonial times to present. After gaining independence, the country introduced “free” water policy in its rural areas. Criticism against this policy was expressed already in the 1970s, but it was not until the late 1980s that change became unavoidable. All the while urban water tariffs continued to decline in real terms. In rural and periurban areas of Tanzania consumers often have to pay substantial amounts of money for water to resellers and vendors since the public utilities are unable to provide operative service. Besides, only a part of the water bills are actually collected. Now that the free water supply policy has been officially abandoned, the development of water tariffs and the institutions in general are a great challenge for the country.     

Recovery of gold by chicken egg shell membrane-conjugated chitosan beads

We have successfully prepared a bead-type adsorbent from two materials with different adsorption characteristics. Heavy metals were removed by greatly swollen egg shell membrane-conjugated chitosan beads. The egg shell membrane accumulated and removed precious metal ions from a dilute aqueous solution with a high affinity in a short contact time. Experiments suggested that chitosan beads could take up gold ions with great capacity and selectivity by conjugation with egg shell membrane. Under certain conditions, the selective removal of gold and copper in a mixture of gold and copper ions by egg shell membrane-conjugated chitosan beads was 100% and 2%, respectively. Egg shell membrane-conjugated chitosan beads can be seen as a promising material to recover gold in wastewater from various industries, such as electroplating.     

Soil Phosphorus Concentrations in Dane County,Wisconsin, USA: An Evaluation of the Urban–Rural Gradient Paradigm

Understanding the magnitude and location of soil phosphorus (P) accumulation in watersheds is a critical step toward managing runoff of this pollutant to aquatic ecosystems. Here, I examine the usefulness of urban–rural gradients, an emerging experimental design in urban ecology, for predicting extractable soil P concentrations across a rapidly urbanizing agricultural watershed in southern Wisconsin. I compare several measures of an urban–rural gradient to predictors of soil P such as soil type, slope, topography, land use, land cover, and fertilizer and manure use. Most of the factors that were expected to drive differences in soil P concentrations were found to be poor predictors of Bray-1 (extractable) soil P, which ranged from 4 to 660 ppm; while there were several significant relationships, most explained only a small proportion of the variation. A multiple linear regression model captured approximately 37% of the variation in the data using the urban–rural gradient, topography, land use, land cover, manure use, and soil type as predictors. There was a significant relationship between Bray-1 P concentration and each of the urban–rural gradients, but these relationships explained only between 2.6% and 3.3% of the variation in P concentrations. Extractable P concentration in soils, unlike some other ecosystem properties, is not well predicted by urban–rural gradients.     

污水处理磷回收的研究进展

磷矿数量减少与含磷污水造成的水体富营养化问题对磷资源的可持续利用提出了迫切要求。从污水处理的不同环节回收磷并重新利用,是实现磷资源循环利用的有效途径。本文讨论了国内外磷回收技术的研究进展和应用实例,包括从含磷污泥和富磷污水中回收磷的工艺,并对磷回收的技术经济性进行了分析。     

从6-APA和7-ADCA生产废液中回收苯乙酸

采用溶剂萃取、水法提取等方法从6-氨基青霉烷酸和7-氨基-3-去乙酰氧基头孢烷酸生产废液（简称废液）中回收苯乙酸（PAA）,考察了各种因素对回收效果的影响。实验结果表明：以甲苯为萃取剂,在萃取温度30℃、萃取时间15m in、500mL废液中萃取剂加入量130mL的最佳条件下,萃取率为96.5%;在提取温度为65℃左右、结晶温度低于10℃的条件下,PAA收率大于89%,纯度大于99%;所得PAA产品质量好,可用于青霉素G等医药产品的生产。