Pore structure and adsorption properties of carbonized material prepared from waste paper

We have already reported the adsorptivity and pore structure of activated carbon made from waste newspaper in order to use the waste paper for purposes other than paper-making stock. However, manufacturing the activated carbon may not necessarily be an advantageous method based on environmental concerns and the effective use of the resource because the reaction during the activating process is endothermic and the amount of carbon consumed is significant. Here, we examine the pore structure and adsorption properties of waste newspaper used as an adsorbent in the form of a carbonized material. Waste newspaper was carbonized for 2 h in the temperature range 400°–1000°C. The specific surface area of the carbonized material obtained, 418 m²/g, was highest for the sample carbonized at 800°C, which was equal to or greater than that of commercially available charcoal. Moreover, the iodine adsorption number of 581 mg/g was the highest and the rate of adsorption was the fastest for the sample carbonized at 800°C. However, the humidity control capability was highest for the material carbonized at 600°–700°C. It has been determined that it is advantageous to carbonize waste paper at 800°C in order to use the carbonized material as an adsorbent, while carbonization at 600°–700°C is more advantageous for use as a humidity control material. Received: June 23, 2000 / Accepted: January 17, 2001     

膜化学技术在造纸废水深度处理中的应用研究

采用膜化学反应器对造纸废水的二级生化出水进行了实验 ,讨论了废水通过膜化学反应器时 ,温度、pH值、氧化剂AK的剂量、曝气量等主要影响因素对废水CODCr去除率的影响 ,结果表明 ,最佳工艺条件下CODCr、色度的去除率达 87 1%、95 % ,出水CODCr<10 0mg L ,出水完全可以回收利用。     

造纸行业的污染防治

造纸业是造成水污染的重要污染源之一.针对造纸行业废水的来源、特点及对环境造成的危害,提出造纸废水的几种处理方法,并对如何防治造纸行业污染提出一些思路与对策.     

造纸废水中悬浮物的测定方法研究

在测定造纸废水悬浮物的过程中,采用絮凝沉淀法破坏废水中的胶体物质,从而提高抽滤速度,缩短测定时间。达到快速测定造纸废水中悬浮物的目的。     

浆纸企业CO2排放因子分析及计算方法研究

根据浆纸生产的工艺特点和生产实际,推导出主流的制浆技术、造纸技术、浆纸废渣替代燃煤、沼气替代燃煤的CO2排放因子分别为0.229,1.304,1.5,3.69t/t.以此为基础并参考相关的资料,分析了纸机的不同部位对CO2排放因子的影响,并模拟了不同生产规模时CO2排放总量.结果表明:浆纸企业CO2排放总量中,造纸系统和废物处理系统占据主导地位分别为54.23%和33.86%,造纸系统和制浆系统中耗热工段对CO2总量的贡献比例分别为75.6%和90.22%,废物处理系统中,浆纸废渣任意弃置和沼气任意排放CO2总量的贡献比例分别为46.06%和47.59%.     

锰离子掺杂纳米二氧化钛的制备及在造纸废水处理中的应用

以无机盐无水四氯化钛为原料,采用溶胶-凝胶法制备的锰离子掺杂型纳米TiO2作为光催化剂,在高压汞灯的光源照射下对河北省某造纸厂废水进行光催化降解。考察Mn2+/TiO2光催化剂的热处理温度、掺杂量、用量及溶液pH值、光照时间等因素对废水COD降解率的影响。实验结果表明:经460℃热处理1h的Mn2+/TiO2光催化效果较好,在进水ρ(COD)为400 mg/L,初始pH值为4.0、光催化剂用量1.5g/L、光照时间9h条件下,COD去除率可达80.3%。经深度处理的造纸废水,可实现达标排放。     

Histopathological impact of industrial wastewater on the vital organs of Oreochromis mossambicus

The acute toxicity of paper mill wastewater to Oreochromis mossambicus was investigated with the lethal concentration (LC50) value 6.5% for 96?h exposure. This concentration was used as a baseline to study the effects of paper mill effluent on histopathological changes in gills, liver, kidney, and brain of fish. In the gills, filament cell proliferation, cellular infiltration, hemorrhage, and epithelial lifting were observed. In the liver, vacuolation of hepatocytes and necrosis were noted. In kidney, exfoliation and swollen with pyknotic nuclei were identified. Similarly, the brain also showed enlarged pyramidal cells, binucleated nuclei, vacoulation, and necrosis. These changes occurred predominantly in 21days following exposure of fish to the industrial waste water. Paper mill wastewater was found to be highly toxic to fish.     

Influence of short-term irrigation of textile mill wastewater on the growth of chickpea cultivars

The effect of textile mill wastewater on germination, delay index, physiological growth parameters, and plant pigments of two cultivars of chickpea was studied. The aim of this study was to evaluate the suitability of textile mill wastewater (treated and untreated) at different concentrations (0, 6.25, 12.5, 25, 50, 75, and 100%) for irrigational purposes. The textile effluent did not show any inhibitory effect on seed germination at a lower concentration (6.25%). The other reported plant parameters (delay index, root length, shoot length, dry weight, chlorophyll, and carotenoid) also followed a similar trend. Seeds germinated in 100% effluents but did not survive for longer periods. It has also been concluded that the effect of the textile effluent is cultivar-specific, and due care should be taken before using the textile mill wastewater for irrigation purposes.     

Bioleaching of copper from pre and post thermally activated low grade chalcopyrite contained ball mill spillage

Bioleaching of a low grade chalcopyrite (ball mill spillage material) was tested for copper recovery in shake flasks. The original samples (as received) were thermally activated (600°C, 30 min) to notice the change in physico-chemical and mineralogical characteristics of the host rock and subsequently its effect on copper recovery. A mixed culture of acidophilic chemolithotrophic bacterial consortium predominantly entailing Acidithiobacillus ferrooxidans strain was used for bioleaching studies and optimization of process parameters of both original and thermally activated samples. Mineralogical characterization studies indicated the presence of chalcopyrite, pyrite in the silicate matrix of the granitic rock. Field emission scanning electron microscopy coupled with Energy dispersive spectroscopy (FESEM-EDS) and X-ray Fluorescence (XRF) analysis indicated mostly SiO₂. With pH 2, pulp density 10% w/v, inoculum 10% v/v, temperature 30°C, 150 r·min^-1, 49% copper could be recovered in 30 days from the finest particle size (-1+ 0.75 mm) of the original spillage sample. Under similar conditions 95% copper could be recovered from the thermally activated sample with the same size fraction in 10 days. The study revealed that thermal activation leads to volume expansion in the rock with the development of cracks, micro and macro pores on its surface, thereby enabling bacterial solution to penetrate more easily into the body, facilitating enhanced copper dissolution.     

The effectiveness of cluster approach to improve environmental corporate performance in an industrial district of SMEs: a case study

This paper aims to assess the effectiveness of the so-called ‘Eco-Management and Audit Scheme (EMAS) cluster approach’ when applied to environmental policies, by focusing on the case history of the industrial paper production cluster located in the Province of Lucca (Italy). The Lucca cluster represents approximately 20% of Italian paper production, and Italy is the fourth leading paper producer in Europe. In the last 10 years, environmental policies have been developed under the common ‘umbrella’ of a strong public and private partnership based on stakeholder networking within the application of the EU EMAS Regulation. This article evaluates the outcome of such an approach, by comparing the environmental performance indicators for the Lucca’s paper industry using data collected from more than 40 plants before and after the adoption of this voluntary tool. The results show considerable improvements for many environmental performance indicators, consistently with the implementation of the cluster approach.