Evaluation and Optimization of Old Magzines Deinking Process of a Modified Lignin Sulfonates Deinking Agent

Deinking is an important process in waste paper recycling process,and this study mainly focuses on the properties of the deinking agent and process optimization.DIA-30 prepared in our laboratory,and FS and LD,were the three representative deinking agents studied herein.Brightness,effective residual ink concentration(ERIC),dirt,macro-stickies,fiber loss during repulping,flotation,and washing processes were measured to evaluate the performance of the deinking agents and optimize process conditions.Each of the deinking agents exhibited different advantages:DIA-30 was optimal for deinking efficiency,brightness enhancement,as well as dirt and macrostickies removal,whereas LD was optimal for ink removal during flotation process but performed poorly in terms of brightness enhancement.FS showed a relatively balanced performance compared to those of DIA-30 and LD in the deinking process,but DIA-30 is the best option for deinking due to its outstanding comprehensive properties.The optimal repulping conditions for the deinking of 100%old magzines(OMG)using DIA-30 are as follows:repulping temperature,60℃;pulp consistency,13 wt%;repulping time,20 min;H2O2 dosage,0.5 wt%(oven-dried pulp);NaOH dosage,1.2 wt%(oven-dried pulp);Na2SiO3 dosage,0.3 wt%(oven-dried pulp);and optimum DIA-30 dosage,0.1 wt%.

Comparisons between Flotation Deinking Abilities of Newsprint Paper by Using Enzyme and Chemicals

The aim of this research is to study the floatation deinking abilities of black mold enzyme and chemicals in newsprint paper application. In this experiment, the properties of deinked pulp from three different additives--chemicals, black mold enzyme, and chemicals together with black mold enzyme, are studied. The first part of the experiment was to find the optimal amount of chemicals and the optimal pH through the use of sodium hydroxide and surfactant. As a result, 0.2% of sodium hydroxide and 0.4% of surfactant on oven dried weight at pH 9 was found to be the optimal condition for the deinked pulp to yield the lowest ERIC （effective residual concentration） and the highest brightness. The second part of the experiment was to find the optimal amount of black mold enzyme used in the deinking process. As a result, the optimal condition for deinked pulp to retain the lowest ERIC and the highest brightness was 100 ppm of black mold enzyme and 10 minutes of enzyme reaction time. The third part of experiment was to study the de-inking ability of black mold enzyme and chemicals. Consequently, with 30 min of chemicals reaction time and 60 min of black mold reaction time, the deinked pulp retained low ERIC but higher brightness.

Continuous Biological Treatment of Ozone Pre-treated Membrane Concentrates of Deinking Wastewater Streams from Pulp and Paper Industry

The implementation of the European WFD （water framework directive） requires IWRM （integrated water resource management）, an important tool in managing available water resources in the presence of emerging constraints. Pressures caused by variability in water supply cycles, droughts, pollution, industrialization, increasing domestic and commercial demand, inadequate infrastructure, intense urbanization and population growth, and decrepit distribution networks have led to the increasing exploitation of industrial wastewater. Most industrial process has some negative impacts on the environment especially on a catchment scale i.e. water, air and soil quality. In the context of water resources and environmental protection measures, the term ＂sustainable development＂, a development that is compatible with the future gains and environmental protection, is regulated more and more by law. To comply with these emission-based limit values, so-called ＂end-of-pipe-techniques＂ are used. Experimental results show CBT （continuous biological treatment） processes present secondary measures to purify highly contaminated industrial wastewater.

Treatment and Resource Utilization of Deinking Sludge from Regenerated Paper Mill

To fully utilize secondary resources,it will inevitably generate a large amount of deinking sludge using waste paper as raw material for paper making.The sludge contains small fibers and dissolved substances of various chemicals.After adding flocculant and settling treatment,deinked sludge is formed.However,its organic matter content can reach a high level of 40%to 50%,and it can also be reused,effectively avoiding the harmful impact of papermaking sludge on the environment.

国内废旧报纸(ONP)脱墨工艺条件的研究

对国内废旧报纸(ONP)脱墨过程以及其主要工艺参数对脱墨浆纸张性能指标的影响情况进行了实验室研究,实验结果表明:在脱墨体系浆浓1%,脱墨温度为60℃,保温时间为30min的条件下,实现ONP脱墨的适宜脱墨工艺条件为NaOH2%、Na2SiO34%、TM-1用量0.2%,EDTA用量0.6%,H2O2用量1.0%。另外,我们还对保温温度、保温时间以及碎解时间对脱墨效果的影响作了较为深入的研究。