2005年11月 紙パ技協誌

 

Innovative Technology Reduces Both COD and Through Deoxidization

Norifumi Yoshida
Aience Co., Ltd.

 Biological processes, in particular activated sludge are commonly used as secondary treatment methods in paper-industry sewage systems. What is less widely known, however is that the use of an aeration system (aeration efficiency) can greatly improve treatment performance. It would be no exaggeration to say that because most drainage treatment plans operate independently of production facilities, an unnecessarily high degree of carelessness is common in the industry. A little more attention in this area could substantially cut losses in a company’s net profits. As the term biological process suggests, by activating microorganisms, it is possible to reduce the amount of BOD and COD in wastewater.
 But when use incorrectly this basic technique can be counterproductive, making it difficult to reduce the load and at the same time, producing a large quantity of sewerage. What causes this to occur? The answer lies in the subtle relationship between oxygen and microorganisms, which when not properly dealt with can create needless problems. Microorganisms, with the exception of large amounts of artificially created chemical substances, thrive in direct relation to their immediate environment. And like human beings, some microorganisms metabolize energy with oxygen. In other cases, they metabolize with nitric-acid or sulfuric-acid ions. However, by using aerobic drainage treatment methods such as activated sludge that cause non-oxygen metabolization, not only does a decrease in treatment speed occur, but odor and bulking (filamentous bacterium) frequently result. To prevent these unwanted consequences, it is necessary to efficiently diffuse the oxygen in the BOD load in an existing diffusion tube becomes, the more difficult the process becomes.
 To solve this problem, by raising the water and sludge from the bottom of tank, Aience’s revolutionary water treatment system makes use of a technique that greatly circulation of the water and improves performance in a way that has been impossible until now.


The Latest Environmental Load Reduction Technology in Wastewater Treatment

Katsura Kitatsuji
Engineering Dept. Eco-sojyution Group, Facility Management Services Division, Kurita Water Industries LTD.

 Three systems were introduced as the latest environmental load reduction technologies. 1) The supercritical water oxidization system uses supercritical water to rapidly decompose organic compounds into water and CO2. It can carry out complete decomposition of the high strength organic matter, organic sludge and persistant organic pollutants. 2) ANAMMOX Bacteria have completely different new nitrogen metabolism from other bacteria, and generate nitrogen gas from nitrous acid and ammonia under anaerobic condition. By combining nitrous acid oxidization and ANAMMOX reaction, significant reduction of treatment cost and CO2 can be achieved compared to the conventional nitrogen removal system. 3) The activated sludge system utilizing protozoa generates 70% or fewer excess sludge compared with a standard activated sludge process without additional energy requirement.
 The following three systems were introduced as environmental load reduction technologies in the paper and pulp industries. 1) Moving bed biofilm reactor is the latest biofilm process. Backwashing is not required in MBBR and the maintenance is very easy. Because of the high treatment efficiency, low concentration wastewater can be processed within shorter time. It is also more suitable for wastewater treatment process of paper and pulp industries. 2) The super-high loding anaerobic reactor was developed by improving UASB. Applicability to KP drainage, DIP wastewater, and neutral paper-making wastewater have been already confirmed. 3) The chemical addition control system based on optical dispersion sensor is applied to flocculation process and dewatering process of excess sludge. The sensor detects the optimal flocculation condition using laser light dispersion and optimises the chemical dosage. Compared with in manual operation, about 30 percent reduction of the chemical dosage is possible. Moreover, combined use of ogranic coagulants in this system enhances further reduction of inorganic coagulants.


Status and Trend of Environmental Laws and Regulations

Shigenori Imamiya
Oji paper Company Limited Environmental Management Dept.

 Since the 1990s, many environment-related laws and regulations have been enacted and put in force, one feature of which is the reinforcement of waste and chemical substance management for environmental conservation. The other is the establishment of a framework for a sustainable society, ranging from effective utilization of resources and eco-friendly goods to environmental report and education. Ministry of the Environment has played the central role in these environmental policies after the reorganization in January 2001.
 As for waste management, twelve laws have been promulgated between 1995 and 2000, 6 of which are recycling-related ones. And "Waste Management and Public Cleansing Law" has been frequently revised for the past few years including the revision in May 2005, though it was said that the revision in 2000 was final. This law must be paid attention by not only person in charge but also business people because the industrial waste is generated in wide range of businesses irrespective of its size and has to be treated under many requirements.
 In regards to chemical substance management, effective laws and regulations have been implemented to reduce pollutants such as Dioxins. On the other hand, the voluntary action practiced by industry sectors has been also efficient to decrease hazardous chemicals, in accordance with the principles of “PRTR law”, “Air Pollution Control Law” and so on, which is very different from traditional approach through national emission standards.
 There are some laws and regulations needed to be monitored cautiously in pulp and paper industry, which is the introduction of VOC regulation in “Air Pollution Control Law”, the revision of total pollutant load control in “Water Pollution Control Law” and the spreading of odor regulation based on humane olfactory perception. Recently PCB waste treatment has begun and early registration discount system by Japan Safety Corporation (JESCO) is currently in progress. It is desirable to cope with this type of movement in a planned manner.


What is Multi-chemical Sensitivity?

Yukio Yanagisawa
Graduate School of Frontier Sciences
The University of Tokyo

 Are there any ones who intend to induce sick-house syndromes or multi-chemical sensitivity problems? Who is responsible for these indoor environmental problems? Any stakeholders of the indoor environment, such as building designers, constructors, and industries of construction materials and consumer products do not intentionally draw the serious problems. They are generated as side effects of mitigation measures of some environmental problems.
 To prevent climate change and resources depletion issues, various new technologies have been developed. Airtight houses can contribute to conserve energy for cooling and heating by reducing air exchange rates. However, the airtight house tends to be more polluted by volatile organic compounds because their concentration is reciprocally proportional to the air exchange rate. Energy conservation by contracting airtight houses conflicts with indoor air pollution. These kinds of dilemma or multi-lemma issues are real causes of sick house syndromes and multi-chemical sensitivity problems.

Keywords: sick house syndrome, multi-chemical sensitivity, dilemma, climate change, resource
       depletion


Waste Utilization Technologies in Japanese Cement Industry

Satoru Hirose
Business Promotion Department, Environmental Business Company
Taiheiyo Cement Corporation

  The cement production process has the special characteristic of being able to use large volumes of waste and by-products as raw materials and fuel. The Japanese cement industry produced 73.5 million tons of cement in 2003 and used 27.6 million tons of waste and by-products as alternative raw materials and fuel. The cement industry can be seen as the nucleus of an industrial cluster in the field of the waste utilization.
  In recent years, though the production output of cement is on a declining trend, the expectations and requests from the society for more utilization of waste are increasing, so the structure of the industrial cluster has been changing. The Japanese cement industry has developed the new technologies for waste management, and worked toward increasing the treatment quantity and the utilization of more difficult items to dispose.
  In this report, the present situation of the waste utilization in Japanese cement industry and the new waste utilization technologies are reviewed.

Keywords: waste utilization, cement industry, incinerated ash of municipal waste, sewage sludge,
       municipal solid waste, chlorofluorocarbon, Ecocement


Eco-Action 21

Shinya Nakayama
Environment and Economy Division, Environment Policy Bureau
Ministry of the Environment

 The recent social and economic system of mass production, mass consumption and mass disposal has offered us convenient and comfortable life. But, it has put huge burden on natural environment, and the balance between the socio-economic system and our natural environment has been severely damaged. Now, the existence of human being is threatening.
 We have to convert this socio-economic system of the 20th century to one which is sustainable and recyclable and is characterized as “suitable production, suitable consumption and minimal disposal”.
 To establish this sustainable recycling society, everyone including business people, consumers and government persons should voluntarily and aggressively take part in the movement. Especially, business enterprises which play a major role in the socio-economic activity are expected to work actively, whether they are large or small or whatever business they are in.
 Large corporations are willingly working for sustainable environment by taking ISO 14001. But, it is also a fact that not a few small business enterprises are pro production and are not affordable in expense for environment conservation. Recently the good behavior for environment conservation is becoming one of requisites for business deal and those who neglect it will surely lose their business opportunities.
 Eco-action 21 targets to urge those small enterprises which are significant in the socio-economic activity to become environmentally friendly. Its characteristics and procedure are discussed.


Simple system setup for ISO 14001

Noboru Takahisa
Japanese Standard Association, Management Systems Enhancement Dept.

 Many enterprises are working to get the certificate of ISO 14001 in Japan. ISO 14001 intends to be helpful to solve global environmental problems like the global warming by individual and voluntary efforts of improving environmental management system in every enterprise. Therefore, it is welcomed that ISO 14001 is more commonly obtained everywhere.
 As recent environmental problems are diversified in many kinds like dioxins, environmental hormones, land pollution and waste disposal, it is more important for enterprises to have their own environment management system which is capable of proper risk management, not one just asking to obey laws. The meaning of getting the certificate exists in this capability.
 Large corporations are getting ISO 14001 and the trend is now prevailing in smaller organizations as well. The incentive of getting the certificate is : better environment conservation work, one of corporation policies, an improved corporation image, an international trend, evaluation by a third party, a requirement by customers, improving corporate management system and eliminating environmental risks. It is important to clarify the intention of introducing ISO 14001 and to get substantial return. Otherwise, it would be for the sake of written forms or be too exaggerated. The author will explain how to set up an efficient system which he calls “simple system setup” through his experience as an inspector.


Compactness for Agility and Stability of Wet-end Process with the POM System Improves the Paper Machine Production Efficiency

Kazumi Fujita
Aikawa Iron Works Co., Ltd.

 The first concept of the POM Compact Wet-End System was the minimizing of the thick stock and the short circuit volume to get fast and precise response for small lot & many grade changes paper production machine. The POMix is a thick stock mixer with small volume and high efficiency to avoid huge volume mixing and machine chests. The POM header is developed for the process that is handled in a closed hydraulic system without tanks and vessels. The back water must be degassed by the POMp before feeding it into the closed system. The POM lock is the very compact system to avoid the seal pit. Contrary to people's fear, it was proved that the POM Compact Wet-End System yielded improved stability and operability. And additionally, it was proved that the POM system is cleaner, smaller energy consumption, better paper strength than traditional system.
 Today, it is recognized that POM Compact Wet-End System improves the productivity not only for the small lot & many grade changes paper production machine, but also for the writing printing paper, the news printing paper, liner paper, board paper, and tissue paper machine.


JK-BC System as A Highly Advanced Waste Water Treatment System
−Waste Water Treatment Test With Bacilli at Paper Mills −

Akira Ikechi
ITOCHU SANKI CORPORATION, Environmental Technology Development Div.
Tooru Shimomura
MITSUBISHI PAPER MILLS LIMITED, HACHINOHE MILL, Power Sec. Pulp Production Dept.

 The JK-BC system is a wastewater treatment system developed as an evolution of activated sludge process and rotating biological contactor process. It uses bacilli (aerobic bacteria) preferentially cultured to a high concentration in combination with JK-BC system (three-dimensional rotating biological contactor) to bring about an evolution in the field of wastewater treatment. The JK-BC system has made it possible to treat high-concentration wastewater to remove nitrogen, phosphor, and odors which cannot be eliminated by the conventional bacteria.


Is Your Slitting System Cutting into Your Profits?

Hainz Herkenrath
Dienes Werke GmbH & Co., KG

 Knowing the details of your slitting operation, can lead to higher quality and reduced costs in some unexpected ways. Many converters and paper manufacturers could have a slow steady profit loss they may not even know about. Perhaps they have got used to frequent knife changes and time consuming set ups of a poorly designed slitter, even though it is costing them money.
 As companies tighten up their operations, many are discovering that they can cut costs, reduce product waste, minimise downtime by taking a look at their slitting systems. Understanding the fundamentals of slitting is important, and knowing how to evaluate a system for a specific application can build up the bottom line.
 Something as simple as changing the process can make a big difference.


Analysis of Behavior of Rosin Glycerin Ester in Rosin Ester Emulsion Size by Visualization Using ToF-SIMS

Yasuyuki Matsushita, Ai Ookura, Takanori Imai and Kazuhiko Fukushima
Graduate school of Bioagricultual Science, Nagoya University
Toshiyuki Kato
Technical Center, Nagoya University

 Recently, in order to prevent water penetration, the rosin size emulsion that contains abietic acid, maleic rosin and rosin glycerin ester has been applied at many mills in neutral papermaking conditions. It is said that the role of the rosin glycerin ester is to prevent the dissolving of abietic acid and maleic rosin into water. To make clear this, the behavior of the rosin glycerin ester in rosin sizes in different papermaking conditions was investigated by ToF-SIMS (time of flight type secondary ion mass spectrometry). To assure certain detection of the rosin glycerin ester, we used a deuterium-labeled rosin glycerin ester synthesized using deuterium-labeled glycerin and analyzed by searching the deuterium ion peak. This labeling method was very useful for our purpose. ToF-SIMS images and the measurement of sizing effectiveness of handsheets prepared in different pH showed that rosin sizes containing rosin glycerin ester exhibited sufficient sizing effectiveness, and rosin glycerin ester still remained on pulp fiber surface in alkaline as well as in neutral papermaking conditions. However, rosin sizes without rosin glycerin ester did not show the size effectiveness in a neutral condition and that suggested abietic acid and maleic rosin were dissolved. This result supported the past research that rosin glycerin ester prevents the dissolving of abietic acid and maleic rosin into water in a neutral condition.

Key words: ToF-SIMS, rosin sizes, rosin glycerin ester, deuterium-labeling


Ink Penetration Mechanisms for Modified Calcium Carbonate-coated Ink-jet Paper

Dmitry Ivutin*, Toshiharu Enomae and Akira Isogai
Graduate School of Agricultural and Life Sciences, the University of Tokyo
Kazumasa Matsumoto† and Kenzo Nakanishi‡
Konica Minolta Technology Center, Inc.

Nowadays, ink jet printing systems are widely used not only for personal use, but for advanced commercial printing capable of outputting variable information continuously, prepress of offset printing, non-contact printing on curved surfaces of packages and many other applications in industry. Manufacturing technology of ink-jet paper, one of the ink-jet media, is rapidly developing, but not keeping pace with improvements in printing speed and size reduction of ink droplets developed by novel ink-jet head technology. Commercial ink-jet papers are made from silica or alumina as a coating pigment, both of which give high image quality, but are expensive. The present work aims at efficient use of calcium carbonate as an alternative of silica for ink receptive coating layers. Commercial calcium carbonate was ground mechanically or dissolved partially with hydrochloric acid to reduce and equalize the aggregates size. Trial ink-jet papers were prepared and some of them were plasma-etched to give a hydrophilic property. The trial ink-jet papers were evaluated in terms of dynamic behavior of ink droplets ejected from a test ink-jet head by a microscopic high-speed video camera system and of ink penetration depth determined by confocal laser scanning microscope (CLSM). Particle size reduction of calcium carbonate pigment by mechanical grinding and hydrochloric acid dissolution decreased ink dot area and dot roughness on the papers. This result suggests that particle size reduction improves image quality. Based on the criterion standard that smaller the dot area, the better the image quality, the efficient processes were mechanical grinding, hydrochloric acid dissolution and plasma-etching in the decreasing order. It is concluded that particle size reduction decreases pore size of the coating structures and consequently ink droplets tend to penetrate deep in coatings rather than spread laterally along surfaces.

Keywords: coating layer, confocal laser scanning microscope, ink-jet printing, grinding, plasma-
       etching