Ecolabeled paper towels: consumer valuation and expenditure analysis

Ecolabeled paper towels are manufactured using post-consumer recycled material and sold in markets using a recycle logo. Environmentally conscious consumers purchase these paper towels and thereby contribute to improving environmental quality. In this paper, we estimate the implicit value placed by consumers on ecolabeled paper towels using a hedonic price function and conduct an expenditure analysis using Heckman's selection model. Using the data set from the Internet-based grocery stores called as Peapod we find that some consumers recognize ecolabels on paper towels and place a substantial, positive price premium on them. The expenditure analysis indicates that for the preferred functional form, the demand for ecolabeled paper towels is inelastic for environmentally conscious consumers. The simulated results from the selection model indicate that a small subsidy for ecolabeled paper towels will not substantially change consumers' purchase decisions.     

Effect of void structure of photocatalyst paper on VOC decomposition

TiO₂ powder-containing paper composites, called TiO₂ paper, were prepared by a papermaking technique, and their photocatalytic efficiency was investigated. The TiO₂ paper has a porous structure originating from the layered pulp fiber network, with TiO₂ powders scattered on the fiber matrix. Under UV irradiation, the TiO₂ paper decomposed gaseous acetaldehyde more effectively than powdery TiO₂ and a pulp/TiO₂ mixture not in paper form. Scanning electron microscopy and mercury intrusion analysis revealed that the TiO₂ paper had characteristic unique voids ca. 10 μm in diameter, which might have contributed to the improved photocatalytic performance. TiO₂ paper composites having different void structures were prepared by using beaten pulp fibers with different degrees of freeness and/or ceramic fibers. The photodecomposition efficiency was affected by the void structure of the photocatalyst paper, and the initial degradation rate of acetaldehyde increased with an increase in the total pore volume of TiO₂ paper. The paper voids presumably provided suitable conditions for TiO₂ catalysis, resulting in higher photocatalytic performance by TiO₂ paper than by TiO₂ powder and a pulp/TiO₂ mixture not in paper form.     

Effectiveness of Treatment Technologies for Wastewater Pollution Generated by Indian Pulp Mills

India has a large number of paper manufacturing units, with mills varying in size of operations and type of product, scattered all over the length and breadth of the country. Present study deals with the survey of four different pulp and paper mills (Mill A, Mill B, Mill C and Mill D) in India, differing in their scale of operation as well as raw material usage. Physico-chemical characterization of wastewaters produced by different processing units like digestor house liquors, bleaching section, paper machine backwaters, combined inlet to the ETP and outlet to ETP, for all the four mills, was conducted. Different parameters like pH, Color, COD, BOD, percent Na, SAR, TDS and Total hardness were analyzed and compared. Highly significant differences were thus found between all the processing units of all four mills with p values < 0.01. This evaluation showed that though these mills have effluent treatment facilities installed in their premises, improvements are still needed to increase their efficiencies for treating the discharged wastewaters.     

Dynamics of colony development in Polistes dominulus: a modeling approach

A simple model based on feedback mechanisms is developed to describe the dynamics of brood production and colony development of primitively eusocial paper wasps. The presence of pupae and empty cells stimulate egg laying, which varies between a basic rate and a physiological maximum. Newly hatched larvae are fed eggs, causing fluctuations in brood demography and forming cohorts of offspring. The basic feedback mechanisms produce emergent colony-level properties such as synchronized development of the brood and mature nest size. Results suggest that it is incorrect to imply colony decline from lack of nest growth, and that production of waves of offspring can be interpreted as the inevitable result of these simple feedback mechanisms rather than the solution to ultimate optimality criteria. Simulations using the parameters estimated in Polistes dominulus Christ are compared to studies of live wasps to test the validity of the model. Comparing simulated results with a perturbation experiment in nature suggests that feedback relationships establish a system that is robust and resilient against severe disturbance. Received: 20 January 1996/Accepted after revision: 27 April 1996     

Relative merits of polystyrene foam and paper in hot drink cups: Implications for packaging

An analysis of the overall relative merits of the use of uncoated paper vs molded polystyrene bead foam in single-use 8-oz cups is described here as a manageable example of the use of paper vs plastics in packaging. In raw material requirements the paper cup required about 2.5 times its finished weight of raw wood and about the same hydrocarbon fueling requirement as is needed for the polystyrene foam cup. To process the raw materials about six times as much steam, 13 times as much electric power, and twice as much cooling water are consumed to produce the paper cup as compared to the polystyrene foam cup. Emission rates to air are similar and to water are generally higher for the paper cup. Virtually all primary use factors favor polystyrene foam over paper. Once used both cup types may be recycled. Landfill disposal of the two items under dry conditions will occupy similar landfill volumes after compaction and will confer similarly slow to nonexistent decomposition to either option. Under wet conditions polystyrene foam will not readily degrade, but may help other materials to do so. Paper under wet conditions will biodegrade to produce methane, a significant greenhouse gas, biochemical oxygen demand to any leachate, and instability to the land surface during the process. Both materials can be incinerated cleanly in a municipal waste stream with the option of energy recovery, to yield an ash volume of 2%–5% of the incoming waste volume. Overall this analysis would suggest that polystyrene foam, with an extension to plastics in general, should be given more evenhanded consideration relative to paper in packaging applications than is currently the case.     

造纸白泥烟气脱硫技术的工业应用

介绍了晨呜集团齐河板纸有限公司4×75t／h燃煤锅炉采用造纸白泥烟气脱硫工艺,着重阐述了SO2吸收系统工作原理和流程,测试了不同pH吸收液和过氧系数对脱硫效率的影响,分析了Na^＋浓度、Cl-、F-浓度对脱硫系统的影响,并与石灰石石膏对比做简单的技术经济比较,为相似装置的设计提供参考。     

气浮法处理钢纸生产废水

钢纸生产废水是含锌的酸性废水．牡丹江市是生产钢纸城市之一。这方面的研究工作多年来一直未开展，含锌酸性废水的污染问题也一直未得到解决．采用气浮法处理该废水，取得了良好的经济和环境效益     

造纸废水高效生化处理情况

阐述了某大型造纸厂的废水处理工艺及运行情况。结果表明：生物酸化单元能够降低废水的ＣＯＤ、ＳＳ指标、提高废水的可生化性，还能通过较长的水力停留时间有效地调节水量与水质，从而保证了二级生物氧化的稳定与高效运行。在二极生化之后，增设水葫芦吸附墉ＣＯＤ、ＳＳ与色度、更好地保护了天然水本的环境质量，且为实现废水的深度处理与回用建立了良好的条件。     

粪大肠菌群快速测定——纸片法的应用

采集苏州具有代表性的地表水水体22个点位的样品,进行粪大肠菌群的测定方法比较,结果表明,《粪大肠菌群快速测定--纸片法》适于测定受粪便污染程度较轻的湖泊水体.但是,该方法的培养时间对阳性管率有明显影响,认为16 h～18 h是比较理想的培养时间.     

Using liquid waste streams as the moisture source during the hydrothermal carbonization of municipal solid wastes

Hydrothermal carbonization (HTC) is a thermal conversion process that can be an environmentally beneficial approach for the conversion of municipal solid wastes to value-added products. The influence of using activated sludge and landfill leachate as initial moisture sources during the carbonization of paper, food waste and yard waste over time at 250 °C was evaluated. Results from batch experiments indicate that the use of activated sludge and landfill leachate are acceptable alternative supplemental liquid sources, ultimately imparting minimal impact on carbonization product characteristics and yields. Regression results indicate that the initial carbon content of the feedstock is more influential than any of the characteristics of the initial liquid source and is statistically significant when describing the relationship associated with all evaluated carbonization products. Initial liquid-phase characteristics are only statistically significant when describing the solids energy content and the mass of carbon in the gas-phase. The use of these alternative liquid sources has the potential to greatly increase the sustainability of the carbonization process. A life cycle assessment is required to quantify the benefits associated with using these alternative liquid sources.