Rotary type regenerative thermal oxidizer (R-RTO) is more compact than the exist type oxidizers. The three port rotary valve and the honeycomb block are installed.
The oxidizer have good abilities for air pollution control and volatile organic compounds (VOC) emissions. Up to 99% of the polluting VOC are converted to harmless water vapor and carbon dioxide by thermal oxidation, while up to 97% of the waste energy is recovered.

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We have already reported the chemical deodorizing method using iron and vanadium which is found to be very effective in the presence of hydrogen peroxide for removing the four foul smelling compounds (hydrogen sulfide, methyl mercaptan, methyl sulfide and dimethyl disulfide). From that time on, we have made a number of its batch tests and made some field tests using the mini-continuous test apparatus in pulp mills.
In this study, we will present some of the test results and show that the system proved to be excellent in deodorizing the practical drainage in pulp mills.

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For the purpose of increasing waste water treatment facility capacity without major expansion of the existing facilities, an experiment was made to apply the VITOX system. The results are introduced here because a sufficiency of data was obtained to confirm the practicability of VITOX system.
The waste water quality was analyzed with an emphasis placed on reduction in COD. In the experiment, the treatment was conducted with the COD volumetric load set in the range of 1.0 to 6.0 kg/m³ · D. COD removal were found ranging from 50 to 70% while SBOD were more than 90%.
And also description is existended to the removal of four odorous substances (hydrogen sulfide, methyl mercaptan, dimethyl sulfide, and dimethyl disulfide).
Reduction of odorous substances are : 56% for hydrogen sulfide, 86% for methyl-mercaptan, 93% for dimethyl sulfide and 78% for dimethyl disulfide. Therefore, it was also found that these odorous substances could be significantly removed.

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It keeps balance on the quality of treating water to have a small quantity of the suurpllus sludge.
Aerobic Biofilm is easy to maintain the control, for it is powerful over the change of the loading and is abundant in the biota.
It is under the influence of the structure of thr water tank or the earation method.
If you made a mistake in plan, it would cause these defects, that is to say the blockade of the filters or the variation of the water course.
AD system makes up for these defects and it is the eration system which uses effectually the surface area of Honey-Comb.

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KROFTA SANDFLOAT is one complete unit consisting of flotation (DAF), sandfiltolation and backwash system in one tank. KROFTA SANDFLOAT tolerates suspended soldis load heaver than conventional sandfilter.
As a first installation in Japan, Krofta sandfloat model 18 was started up in July '95. This sandfloat is adopting new paper machine's white water recovery system for excess & press part white water.

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Recovery and reuse from white water in papermaking process is important for limitation of water source, reduction of waste water and saving of energy.
New recovery system with equipments, chemicals and monitering systems is proposed.
(1) Dual media filter is applied as the secondary treatment of white water.
(2) Charge neutralization agents and high morecular weight PAM are used to keep SS of primary treated water below 20 mg/l.
(3) Slimecontrol agents and slime monitoring system are needed to prevent plugging of shower nozzles in white water recovery line.

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Maintech Co. has been developing Chemical spraying system for paper manufacturing machines to reduce the consumption of the chemical. In this paper requirements to the spraying system are organized and an outline and achievements of our systems are described.

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The surface-sizing-agent (SSA) chemically linked to starch was characterized in comparison with SSA only. It was found that ink-jet properties of paper treated with the SSA-starch system were better than for the SSA only. Furthermore, the SSA-sarch system had more stable performance in surface sizing of paper against changes in concentration of alum, sodium chloride or starch in the surface sizing solutions. Scanning electron microscopic observations of the treated paper surface and optical microscopic observations of model compounds indicated that the SSA-starch system brought about the formation of more homogeneous coated layer of the SSA-starch and starch, added together with the SSA-starch for surface sizing, on paper surfaces.

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A new reactive surfactant (ASA-MA) is found to provide polyacrylamides (PAM) hydrophobic characters. Hydrophobically modified PAM (ASA-PAM) is available for surface size, and the sizing mechanism of ASA-PAM was investigated. The sizing ability of ASA-PAM is dependent on the presence of alum in the paper. The copolymers of ASA-MA and some nonionic water soluble monomers were synthesized, and the sizing abilities and the paper strength abilities were examined. The sizing mechanism is assigned to proceed two steps, that is, ASA-PAM combined with the alum in the paper in the first step, and hydrogen bond between ASA-PAM and the pulp are formed in the next step, and such interactions resulted in the orientation of the hydrophobic groups to the air surface.
Applications of ASA-PAM as dispersing agent or retention agents to SBR latex are also described.

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It has been definitely shown by estimate of paper making machine that characteristic of strength agent for spraying between layers -POLYMJET 902-.
Characteristic of POLYMJET 902 is improve of working process, improve of drying process, decrease of 'fukure' and improve of internal strength.
Meanwhile, problem of POLYMJET 902 is stabilization of diluted solution and change of strength between layers by change moisture of paper making.

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The cleaner systems Shinko Co., Ltd. has mainly handled have been non contact device which would not touch materials. However, it is not effective for this device to remove adhesive particles, which stick into materials, feather shaped fibers at edges and other particlea which have stronger adhesion compared with particles on the normal materials at all for the moment. There must be many demands of this kind of cleaner systems which are effective for there particles among film and paper industries. As quantities of recycled papers are increased, the problems of paper dust are anticipated to be increase, installation of cleaner systems will be definitly needed.
Although some cleaner systems with contact brush have been merchandised, but they had some troubles, such as hurting surface of material by brush, containing surface again by contaminated brush rolls reversely and removed particle could not be exhausted properly, so that cleaner head itself is also contaminated by theae particles. They could not satisfy the demand of customers regarding particle removal effects after all. New type brush cleaner is developed for the purpose in solving all these problems.

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Recently, Shoe-press is often used for light weight paper (Fine paper, News paper) in the world. There are many technical reports for the necessity of using Shoe-press on the light weight paper. So, some considerations when applying Shoe-press to the light weight paper is reported with some actual data here in after.

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Newsprint production is made advanced high speed printing and reduction of labor for the purpose of productivity improvement. From the viewpoint of the environmental issue, the news ink with aromatic free solvents are developed.
The improvements of water repellency and surface strength are required to newsprint for off-set printing with super-light-weight paper or for high speed printing.
In almost all newspaper mills, gate roll coaters are generally installed. Specially the use of poly acryl-amide (PAM) coating agent is spreading. We propose the newly gate roll coating agent with excellent surface strength as well as high water repellency.

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Coating colors of different dewatering rate were prepared. These colors were coated on a wood-containing paper by a pilot gate roll coater. Surface properties such as fiber coverage, uniformity of coating, smoothness and sheet gloss of gate-roll-coated paper were evaluated. Relation between water retention of coating color and surface property of gateroll-coated paper was discussed.

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The effects of components on the environmental assessment for pulp and paper mill effluents were discussed. Studies on the formation and toxic contribution of main components and parameters in 17 whole mill effluents suggested that the environmental impact of the effluents did not depend upon a well-known effluent component like AOX, chlorophenol and chlororesin acid, but a cluster of components such as COD/BOD. The Toxicity Identification Evaluation (TIE) must be studied for the further discussion of more specific effect by any component or source in a mill effluent.

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We have developed a novel ozone generator which can produce high concentration ozone up to 300 g/Nm³ (20 wt%). The ozone production efficiency is significantly improved in comparison with a conventional ozone generator ; the energy consumption is 10 kWh/kgO₃ at a ozone concetration of 240 g/Nm³ (16 wt%) In addition, the novel ozone generator is much smaller in size. The development of the novel ozone generator is expected to extend ozone applications for various purposes, such as pulp bleaching.

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Diversity of sludge type due to the development of higher levels of waste water treatment, increased quantities of difficultly dewatered sludge, higher unit costs of industrial waste treatment and so forth call for sludge dewatering devices which can reduce the volume of dewatered sludge cake and require a minimum of operator attention and maintenance. Organo's new Screw Press Sludge Dewatering Equipment CPHS has been developed to meet with such requirements. This sludge dewatering equipment is the culmination of many years of Organo's experience not only in manufacturing various types of sludge dewatering equipment but also in the coagulation technology using polyelectrolyte coagulants. This patented equipment has three features. Firstly, sludge under pressure is automatically introduced to a screw press. More specifically, coagulated sludge is pushed into the screw press on the strength of the delivery pressure of a sludge feed pump. Secondly, this sludge dewatering equipment is provided with an automatic high pressure cleaning system which consists of a cleaning header fitted out with spray nozzles. This cleaning header moves back and forth to clean punching metal (filter medium) with water under high pressure. Thirdly, the screw press is characterized by a unique cake scraper which is designed to squeeze the dewatering cake by means of a keep plate located at the outlet of the screw press. This keep plate is forcibly opened and closed via a hydraulic cylinder. These features lead to such advantages as shorter lengths ofscrew press, (L/D=3 5), little splashing of odors and/or sludge from the coagulation tank, etc., no lagging of the punching metal (to present higher moisture content of cake anddrop in broghout (?) capacity of the screw press), less cleaning requirements, lower moisture content of cake squeezed under high pressure, no overloading on the screw.press, and better control of dewatering. In preparing coagulated sludge to be fed to the screw press, it is very important to form large aggregates or flocs which are stable and so not disintegrate. Cationic and anionic polyelectrolytes and inorganic coagulates or combinations thereof are used depending upon sludge characteristics. The Screw Press Sludge Dewatering Equipment CPHS has found wide use in food processing, chemical, machine and metal industries. We believe this equipment will also come into its own in the treatment of sludge generated from wastewater treatment in the pulp and paper industry.

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In order to learn the effectiveness of pyrolysis-gas chromatography (Py-GC) on the characterization of chemically or biologically modified lignin, decayed hardwoods and kraft-cooked hardwoods were subjected to Py-GC as a tool for the convenience lignin analysis tool. The selected guaiacyl pyrolysis products (guaiacol, 4-methylguaiacol, 4-ethylguaiacol, 4-vinylguaiacol, eugenol, vanillin, rans-isoeugenol and trans-coniferyl alcohol) and their syringyl analogue (syringol, 4-methylsyringol, 4-ethylsyringol 4-vinylsyringol, 4-allylsyringol, syringaldehyde, trans-4-propenylsyringol and trans-sinapyl alcohol), as the main lignin-derived compounds, were determined using each absolute calibration factors to flame ionization detector. The results were compared with those by the alkaline nitrobenzene oxidation.
European beech (Fagus silvatica) woods were decayed by a brown-rot fungus (Tyromyces palustris) or a white-rot fungus (Coriolus versicolor), and beech (Fagus crenata) woods were cooked with kraft liquor. Residual lignin contents of wood samples were measured by the Klason lignin methods. Lignin was analyzed by Py-GC and the alkaline nitrobenzene oxidation method quantitatively without isolation from woods. The yields of the pyrolysis products were obtained on the basis of the residual lignin in decayed woods, and changes in the yields and their relative compositions during the decay for 180 days were investigated. The molar ratios of syringyl type pyrolysis products to guaiacyl ones (S/G ratios) measured by Py-GC were compared with the molar ratios of syringaldehyde to vanillin (S/V ratios) obtained by the nitrobenzene oxidation.
(1) In pyrolysis of 180 days-decayed woods by Tyromyces palustris, the yields of trans-coniferyl alcohol and trans-sinapyl alcohol sharply decreased.
(2) In those by Coriolus versicolor, the yields of trans-coniferyl alcohol and trans-sinapyl alcohol decreased, and relative compositions of guaiacoland syringol clearly in-creased.
(3) For decayed woods by Coriolus versicolor, the yields of syringyl type pyrolysis products decreased more rapidly than those of guaiacyl ones with increase of decaying days. The S/G ratios measured by Py-GC were in good agreement with the S/V ratios obtained by the nitrobenzene oxidation.
(4) In pyrolysis of kraft-cooked woods, the yields of trans-coniferyl alcohol and trans-sinapyl alcohol decreased, and relative compositions of guaiacol and syringol increased.
(5) The S/G ratios of residual lignin in kraft-cooked woods decreased with increase of cooking time, and those were in good agreement with the S/V ratios.

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