Application of cupuassu shell as biosorbent for the removal of textile dyes from aqueous solution

The cupuassu shell (Theobroma grandiflorum) which is a food residue was used in its natural form as biosorbent for the removal of C.I. Reactive Red 194 and C.I. Direct Blue 53 dyes from aqueous solutions. This biosorbent was characterized by infrared spectroscopy, scanning electron microscopy, and nitrogen adsorption/desorption curves. The effects of pH, biosorbent dosage and shaking time on biosorption capacities were studied. In acidic pH region (pH 2.0) the biosorption of the dyes were favorable. The contact time required to obtain the equilibrium was 8 and 18 h at 298 K, for Reactive Red 194 and Direct Blue 53, respectively. The Avrami fractionary-order kinetic model provided the best fit to experimental data compared with pseudo-first-order, pseudo-second-order and chemisorption kinetic adsorption models. The equilibrium data were fitted to Langmuir, Freundlich, Sips and Radke-Prausnitz isotherm models. For both dyes the equilibrium data were best fitted to the Sips isotherm model.     

载钯树脂对偶氮类染料的吸附降解及其产物对发光菌的毒性暴露试验

合成了表面负载金属钯的聚丙烯醛异烟酰腙树脂后,通过Q67发光菌的毒性暴露实验研究了该树脂材料对直接大红、直接天蓝和桃红等3种水溶性偶氮染料的催化降解效果及其在降解过程中对发光菌的生物毒性变化情况,并对降解结果进行了气相色谱-质谱(GC-MS)分析.实验结果表明:载钯树脂对直接大红、直接天蓝和桃红等偶氮染料具有良好的吸附...     

高浓度脱浆污水的湿式氧化法处理研究

介绍了采用湿式空气氧化法（ＷＡＯ）对来自香港两个纺织工厂的脱浆污水进行处理的效果。所用装置为１台２Ｌ的高温高压釜。操作工况为：温度１５０￣２９０℃，氧分压０．３７５￣２．２５ＭＰａ。在每个试验的不同过程中监测了ｐＨ值、ＣＯＤ、ＴＯＣ的变化，以评估各个过程的转化效果。还研究了温度、氧分压及反应时间对处理效果的影响。对生化性很差的化学纤维脱浆污水，其ＣＯＤ、ＴＯＣ去除率分别达到９０％和８０％。     

Possibilities and limitations of a comparative assessment of process technologies from a cleaner production point of view

This article presents a method for a comparative assessment of process technologies from a cleaner production point of view as well as the results of testing this method in practice. Based on these results and on an analysis of existing technology information systems, an estimation is made of the general possibilities and limitations of a comparative assessment of process technologies from a cleaner production point of view. Finally, the resulting consequences for the definition of ‘best available techniques' in accordance with the new EC Council Directive Concerning Integrated Pollution Prevention and Control (IPPC) are discussed. This article argues that apart from the difficulties related to the valuation of different kinds of materials and energy a major limiting factor is caused by the fact that the function of a production has to be defined very precisely to enable a comparison between different types of process technologies in sufficient detail.     

Regeneration of industrial district wastewater using a combination of Fenton process and ion exchange—A case study

Regeneration studies of wastewater effluent from an organized industrial district (OID) for possible reuse in textile industry as process water was investigated. Advanced treatment methods including Fenton process, polyaluminium chloride (PAC) coagulation and ion exchange were applied on OID effluent. In Fenton process removal efficiencies for suspended solids (SS), chemical oxygen demand (COD), SAC₄₃₆ (spectral absorption coefficient), SAC₅₂₅ and SAC₆₂₀ were determined 61%, 36%, 35%, 49% and 67%, respectively. After Fenton process, wastewater samples were coagulated with PAC. Optimum removal efficiencies for SS, COD, Fe ion, SAC₄₃₆, SAC₅₂₅ and SAC₆₂₀ were determined 83%, 18%, 93%, 32%, 36% and 58%, respectively. Ion exchange experiments were conducted on chemically coagulated wastewater samples to improve the quality of wastewater. Optimum dosage of resins was determined. The experiments revealed that 1:1 resin ratio (20 mL H-type resin:20 mL OH-type resin) gave the best removal rates for the parameters considered in this study. Study results indicated that quality of the wastewater was suitable for the process water characteristics of textile industry and unit wastewater treatment cost was determined as 2.54 €/m³.     

Electrochemical reduction in vat dyeing: greener chemistry replaces traditional processes

In application of vat dyes the substitution of non-regenerable reducing agents such as Na₂S₂O₄ by cathodically regenerable reducing agents offers great ecological advantages. In a demonstration project a 45 A multi-cathode electrolyser successfully was coupled to a dyeing apparatus for package dyeing with a capacity of 1–10 kg material. Iron-complexes with triethanolamine and Na-d-gluconate were used as cathodically regenerable reducing agents. Dyebath regeneration was performed by ultrafiltration. Substantial reduction in chemical consumption and reduction in wastewater volume, released from the dyeing process could be demonstrated. Quality of dyeings was assessed with regard to levelness and iron content analysed in the dyed samples.     

纺织印染行业环境保护验收技术规范修订研究

通过对纺织印染行业基本情况和生产工艺特征的现状调研,分析了修订该行业环境保护验收技术规范的必要性。明确了修订工作的基本原则,并针对生产工序复杂、监测内容覆盖面广、原辅用料种类多、技术适用性要求高等难点问题,提出在充分调研的基础上,结合现行法律法规和环境管理的要求,细化验收要点,细分产污环节,确保技术规范的实用性和可操作性,提升纺织印染行业环境保护自主验收水平。