In Japanese pulp and paper industry, the most of the stack gas desulfurization devices installed with oil fired boilers adopt sodium hydroxide process. Chemical effluent (sodium salts) from this process is further reused as chemicals for KP, SCP and CGP.
However, this process tends to give an excess sodium salts in pulping chemical system, other methods have been also developed, such as sodium alminate desulfurization, the resultant effluent of which is used for discharge water treatment. Pulp mill effluent treated with sea water lime process can also be used for desulfurization.
In paper mills which do not have pulping operation, magnesium hydroxide process or semi-wet soda process is used.

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In July of 1977, MOXY System I began operation at Northwood Pulp, Ltd. in Prince George, British Columbia. Northwood Pulp produces about 750 short tons per day of bleached softwood kraft for the market, and is jointly owned by Noranda Mines Ltd. and The Mead Corporation.
Northwood Pulp is noted for its fine fiber characteristics and its superior strength properties. It is generally regarded as one of the best softwood krafts available in the market. Prior to the installation of the MOXY System at the mill, extensive laboratory work had been done to compare the quality attributes of the MOXY-type kraft pulp with regular kraft pulp. Some of these results were published in a previous Technical Bulletin. P-003 (March, 1975).
While only minor changes in quality attributes were found in these laboratory studies, it was agreed that the initial production of the MOXY-type pulp would be sent only to the Chillicothe, Ohio mills of The Mead Corporation for prolonged trials on several paper machines. Approximately 4, 000 tons of MOXY-type pulp was produced in July at Northwood. This report summarizes the results obtained using this pulp on the paper machines at Chillicothe.

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1. 悪臭対策以前の状況
鈴川は, 北に富士山, 南は駿河湾に面した静かな農村であった。昭和12年, 内地で最初のクラフト工場が建設されたが, 工場の規模は拡大され, 他の産業も立地し, 工業地帯と変った。
公害問題は, 当初粉じん, 次いで田子の浦港のヘドロ, そしてクラフト工場の悪臭が問題となった。
2. 新施策
鈴川工場は, 1971年に新たなポリシイを決めた。
(1) 鈴川工場は公害を出していることを認識する。
(2) 隣接住民との対立を最小にすべく努力する。
(3) 最も効果的な部分より設備改善を進める。
(4) モニターを置いて潜在的な公害原因を探知する
(5) 公害の発生源, 量と, 住民に対するインパクトを調査する。
3. 工程の改善
(1) 悪臭ガスの集合と, キルンとRBでの燃焼。
(2) 排水の蒸気加熱真空型ストリッピング。
(3) RB関係の改善。モードースクラバーの設置, 無臭化ボイラーの設置。大昭和一荏原 (D-E プロセス) の設置。
4. 隣接住民の工程改善に対する反応
ガス集合は, 悪臭減少の評価が出たが, 3～6カ月後には, 悪臭が元にもどった, と言われた。鼻が鋭くなったためである。ストリッピングも評価が高かったが, 同じく3～6カ月後には元にもどった, と言われた。回収ボイラーについては反応が出なかったが, 工場の態度は好感が持たれた。
重要なのは緊急時に濃い悪臭物質が流れた場合, 無臭に馴れた住民にインパクトが大きい点である。
鈴川工場は, 1971年以来, 40名のモニターを配置し, 粉じん, 騒音, 悪臭, 振動のデータを集めている。工場はこれをもとにして, 設備改善を進めたが, その結果が良くモニターの記録に表われた。
悪臭に対する感覚は, 悪臭物質が1/10になって, 1/2になったと感ずると言われる。鈴川工場の悪臭物質は, 1972年と比較して, 8.7%以下であるが, 未だ隣接居住者は, 悪臭が消えたとは思っていない。

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Mitsubishi Paper Mills, Ltd. manufactures market pulps, wood-free printing and writing papers, coated papers and paperboards, specialty papers, and photographic papers at six mills consisting of three paper mills, two pulp mills, and one photographic paper mill.
Hachinohe Mill, inaugurated in 1966, is the company's largest and most modernized consolidated pulp and paper mill. The mill site covering an area of about 1, 100, 000 m2 was selected there in the northern end of Honshu Island to exploit rich water and wood resources, port facilities, labor force, etc.
The mill has a capacity of 288, 000 t/y of paper and paperboard with two off-machine coaters, four paper machines, supported by two sulfate pulp lines and one CGP line. Number of employees is about 800. No. 4 paper machine is a Bel Baie 71 twin wire unit producing wood-free fine papers of excellent quality.
The mill's waste water is treated by a coagulation-sedimentation process. Stack gas from its oil-fired boilers is desulfurized.

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On the basis of “pelletting flocculation”, a new type of sludge blanket clarifier has been developed and already is in commercial use in many fields.
The purpose of this research was to get information concerning the performance of the new clarifier, applied to paper mill effluents. Field tests were carried out with a pilot-scale model of 500 mm in dia. by 2, 500 mm height.
These field tests have demonstrated the excellent performance of the new clarifier, i. e. high removal efficiency of 96% of SS and 80% of COD under 200 mm/min. of the upflow velocity in treating every effluent.
This new clarifier may deserve special consideration for treating paper mill effluents.

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Functional fibers were prepared by grafting acrylamide on to poly- (vinyl alcohol) fibers, followed by converting the grafted amide groups to chemically reactive groups.
Anion exchange fibers were prepared via Mannich reaction using formaldehyde and various kinds of amines. For the aminolation reaction, dimethylamine or polyethylene polyamine was found to be suitable. In the optimum conditions, anion exchange capacities were 1.21.6 meq/gr, depending on the degree of grafting.
After the Mannich reaction, the good cation exchnage fibers were prepared by alkaline hydrolysis of the grafted polyacrylamide part for 1 2 hours at 40°C. The cation exchange capacities increased with increasing reaction time, but the fibers were much swelled.
The absorption of Cu²⁺ of these anion and amphoteric ion exchange fibers was investigated. The anion exchange fibers had the absorbing capacity of 0.4 meq/gr and when absorbed Cu²⁺, they were tinged with green, whereas amphoteric ion exchange fibers absorbed more amount of Cu²⁺ and changed in blue. Maximum absorption of Cu2+ by all the fibers occured at pH 6. These absorptions were due to formation of ammine complex and ion exchange.
Because of the chelation, wet strength of sheets made from these fibers increased by the absorption of Cu²⁺.

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After sulphate pulping, pulps from flax waste and kenaf bark were beaten by a Lampén mill. Beaten pulp fibres were treated with a potassium permanganate solution and embedded in epoxy resin after dehydration. Ultra-thin sections were prepared by a ultramicrotome and observed through transmission electron microscopy. Micrographs of specimens were traced with a densitometer and the following results have been deduced.
Due to beating of pulp fibres, crevices of one to several μm in tangential and radial directions appeared in the secondary walls of flax pulp fibres, followed by separation of fibril bundles. Crevices between lamellae in the secondary walls were not so numerous but conspicuous. So delamination and fibrillation, so called external fibrillation, took place easier in case of flax fibres. On the other hand, external fibrillation was hardly observed in case of kenaf fibres, but delamination severely proceeded, that is, internal fibrillation was most dominant.

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