簡介：

造紙工業(yè)是制造各種紙張及紙板的工業(yè)部門。它包括用木材、蘆葦、甘蔗渣、稻草、麥秸、棉秸、麻桿、棉花等原料制造紙漿的紙漿制造業(yè)，制造紙和紙板業(yè)以及生產(chǎn)涂層、上光、上膠、層壓等加工紙及字型用紙版的加工紙制造業(yè)幾個方面。造紙是我國的四大發(fā)明之一。早在公元前32年到16年西漢成帝時已能制造薄小紙，至公元105年，東漢和帝時蔡倫用樹皮、麻頭、破布、破魚網(wǎng)等代替縑帛和絮作原料，大大推動了手工造紙業(yè)的發(fā)展。世界機器造紙業(yè)則開始于18世紀末。

造紙工業(yè)是一個與國民經(jīng)濟發(fā)展和社會文明建設(shè)息息相關(guān)的重要產(chǎn)業(yè)。
在經(jīng)濟發(fā)達國家，紙及紙板消費量增長速度與其國內(nèi)生產(chǎn)總值增長速度同步。在現(xiàn)代經(jīng)濟中所發(fā)揮的作用已越來越多地引起世人矚目，被國際上公認為“永不衰竭”的工業(yè)，在美國、加拿大、日本、芬蘭、瑞典等經(jīng)濟發(fā)達國家，造紙工業(yè)已成為其國民經(jīng)濟十大支柱制造業(yè)之一?，F(xiàn)代造紙工業(yè)的特點不同于一般日用消費品工業(yè)，而是技術(shù)、資金、資源、能源密集型，規(guī)模效益顯著，連續(xù)、高效生產(chǎn)的基礎(chǔ)原料工業(yè)。在產(chǎn)品總量中，80%以上作為生產(chǎn)資料用于新聞、出版、印刷、商品包裝和其他工業(yè)領(lǐng)域，不足20%用于人們直接消費。造紙產(chǎn)業(yè)關(guān)聯(lián)度大，涉及林業(yè)、農(nóng)業(yè)、機械制造、化工、熱電、交通運輸、環(huán)保等產(chǎn)業(yè)，對上下游產(chǎn)業(yè)的經(jīng)濟有一定拉動作用。當(dāng)今世界各國已將紙及紙板的生產(chǎn)和消費水平，作為衡量一個國家現(xiàn)代化水平和文明程度的重要標志之一。

造紙工業(yè)使用木材、稻草、蘆葦、破布等為原料，經(jīng)高溫高壓蒸煮而分離出纖維素，制成紙漿。在生產(chǎn)過程中，后排出原料中的非纖維素部分成為造紙黑液。黑液中含有木質(zhì)素、纖維素、揮發(fā)性有機酸等，有臭味，污染性很強。

超導(dǎo)高梯度磁力
高梯度磁力分離凈化技術(shù)是用來處理廢水的一種新方法，由于它不會產(chǎn)生雜質(zhì)例如凝絮物，使在短時間內(nèi)處理大量廢水成為可行。
日本Osaka大學(xué)能量和環(huán)境工程系科技人員研究了采用磁力分離系統(tǒng)處理造紙工廠廢水。試驗車間處理造紙廢水為2000 t/d，進行循環(huán)運轉(zhuǎn)達到磁力分離后水中化學(xué)需氧量（CODCr）<40 mg/L。超導(dǎo)磁力管NbTi螺旋管長680 mm、內(nèi)徑400 mm。
該系統(tǒng)主要由混合槽（磁力晶種槽，晶種為有機物、紙漿和染料）、沉淀槽和超導(dǎo)磁力管組成。通過超導(dǎo)磁力分離管內(nèi)的磁力作用，俘獲磁力顆粒和有機聚合物如紙漿和顏料，浮選出磁力短纖維和填料，一部分磁力短纖維和填料通過重力沉降作用，在沉淀槽中沉出，有助于減少循環(huán)水經(jīng)過磁力管時的短纖維和填料量。該系統(tǒng)已成功地運轉(zhuǎn)了幾個月，取得較為滿意的效果。

造紙廢水處理法
造紙廢水主要來自造紙工業(yè)生產(chǎn)中的制漿和抄紙兩個生產(chǎn)過程。制漿是把植物原料中的纖維分離出來，制成漿料，再經(jīng)漂白，這個過程會產(chǎn)生大量的造紙廢水；抄紙是把漿料稀釋、成型、壓榨、烘干，制成紙張，這個過程也容易產(chǎn)生造紙廢水。
制漿產(chǎn)生的造紙廢水，污染為嚴重。洗漿時排出廢水呈黑褐色，稱為黑水，黑水中污染物濃度很高，BOD高達5—40g/L，含有大量纖維、無機鹽和色素。漂白工序排出的造紙廢水也含有大量的酸堿物質(zhì)。抄紙機排出的造紙廢水，稱為白水，其中含有大量纖維和在生產(chǎn)過程中添加的填料和膠料。
造紙廢水處理應(yīng)著重于提高循環(huán)用水率，減少用水量和廢水排放量，同時也應(yīng)積極探索各種可靠、經(jīng)濟和能夠充分利用廢水中有用資源的廢水處理方法。例如：浮選廢水處理法可回收白水中纖維性固體物質(zhì)，回收率可達95%，澄清水可回用；燃燒廢水處理法可回收黑水中氫氧化納、硫化鈉、硫酸鈉以及同有機物結(jié)合的其他鈉鹽。中和廢水處理法調(diào)節(jié)廢水pH值；混凝沉淀或浮選法可去除廢水中懸浮固體；化學(xué)沉淀法可脫色；生物處理法可去除BOD，對牛皮紙廢水較有效；濕式氧化法處理亞硫酸紙漿廢水較為成功。此外，國內(nèi)外也有采用反滲透、超過濾、電滲析等造紙廢水處理方法。

造紙廢水處理劑
聚丙烯酰胺
聚丙烯酰胺在造紙領(lǐng)域中廣泛用作駐留劑、助濾劑、均度劑等。它的作用是能夠提高紙張的質(zhì)量，提高漿料脫水性能，提高細小纖維及填料的留著率，減少原材料的消耗以及對環(huán)境的污染等。聚丙烯酰胺在造紙中使用的效果取決于其平均分子量、離子性質(zhì)、離子強度及其它共聚物的活性。非離子型聚丙烯酰胺主要用于提高紙漿的濾性，增加干紙強度，提高纖維及填料的留著率；陰離子型共聚物主要用作紙張的干濕增強劑和駐留劑；陽離子型共聚物主要用于造紙廢水處理和助濾作用，另外對于提高填料的留著率也有較好的效果。此外，聚丙烯酰胺還應(yīng)用于造紙廢水處理和纖維回收。

硫酸鋁
硫酸鋁極易溶于水，硫酸鋁在純硫酸中不能溶解（只是共存），在硫酸溶液中與硫酸共同溶解于水，所以硫酸鋁在硫酸中溶解度就是硫酸鋁在水中的溶解度。常溫析出含有18分子結(jié)晶水，為18水硫酸鋁，工業(yè)上生產(chǎn)多為18水硫酸鋁。含無水硫酸鋁51.3%，即使100℃也不會自溶（溶于自身結(jié)晶水）。不易風(fēng)化而失去結(jié)晶水，比較穩(wěn)定，加熱會失水，高溫會分解為氧化鋁和硫的氧化物。加熱至770℃開始分解為氧化鋁、三氧化硫、二氧化硫和水蒸氣。溶于水、酸和堿，不溶于乙醇。水溶液呈酸性。水解后生成氫氧化鋁。水溶液長時間沸騰可生成堿式硫酸鋁。工業(yè)品為灰白色片狀、粒狀或塊狀，因含低鐵鹽而帶淡綠色，又因低價鐵鹽被氧化而使表面發(fā)黃。粗品為灰白色細晶結(jié)構(gòu)多孔狀物。無毒，粉塵能刺激眼睛。

焦亞硫酸鈉
焦亞硫酸鈉為白色或黃色結(jié)晶粉末或小結(jié)晶，帶有強烈的SO2氣味，比重 1.4，溶于水，水溶液呈酸性，與強酸接觸則放出SO2而生成相應(yīng)的鹽類， 久置空氣中，則氧化成Na2S2O6，故該產(chǎn)品不能久存。高于1500C，即分解出SO2。
焦亞硫酸鈉用于生產(chǎn)保險粉，磺胺二甲基嘧啶 安乃近，己內(nèi)酰胺等 以及氯仿，苯丙砜和苯 甲醛的凈化。照相工業(yè)用作定影劑的配料。香料工業(yè)用于生產(chǎn)香草醛。用作釀造工業(yè)防腐劑，橡膠凝固劑和棉布漂白后脫氯劑。有機中間體，染料，制革用作還原劑 用作電鍍業(yè)，油田的廢水處理 以及用作礦山的選礦劑等。工業(yè)上用于印染、有機合成、印刷、制革、制藥等部門；在食品加工中作防腐劑、漂白劑、疏松劑。（印染和攝影等方面）、用作漂白劑 媒染劑，還原劑 橡膠凝固劑，也用于有機合成制藥及香料等。

The paper industry is the industrial sector that manufactures a variety of paper and board. It includes pulp manufacturing for pulp production from wood, reed, bagasse, straw, wheat straw, cotton straw, hemp, cotton, etc., manufacturing paper and paperboard industries, and processing, glazing, gluing, lamination, etc. Paper and font paper processing paper manufacturing in several aspects. Papermaking is one of the four major inventions in China. As early as 32 to 16 BC, when the Western Han Dynasty became Emperor, it was able to make thin paper. By the year 105, the Eastern Han Dynasty and Emperor Cai Lun used bark, hemp, rags, broken fish nets, etc. instead of glutinous rice and floc. Greatly promoted the development of the manual paper industry. The world machine paper industry began in the late 18th century.

The paper industry is an important industry closely related to the development of the national economy and the building of social civilization.
In developed countries, the growth rate of paper and board consumption is in line with the growth rate of GDP. The role played by the modern economy has attracted more and more attention from the world and has been recognized as an “never-depleting” industry in the world. In the developed countries such as the United States, Canada, Japan, Finland, and Sweden, the paper industry has become One of the top ten pillar manufacturing industries of the national economy. The characteristics of the modern paper industry are different from the general consumer goods industry, but the basic raw material industry with technology, capital, resources and energy intensive, significant scale benefits, and continuous and efficient production. More than 80% of the total product is used as production materials for news, publishing, printing, commodity packaging and other industrial sectors, and less than 20% is used for direct consumption. The paper industry has a high degree of relevance, involving forestry, agriculture, machinery manufacturing, chemical, thermal power, transportation, environmental protection and other industries, and has a certain pulling effect on the economy of upstream and downstream industries. The production and consumption levels of paper and paperboard have been regarded as one of the important indicators for measuring the level of modernization and civilization of a country.

The paper industry uses wood, straw, reed, rags, etc. as raw materials, and the cellulose is separated by high-temperature and high-pressure cooking to make pulp. In the production process, the non-cellulosic portion of the final discharged raw material becomes a black liquor for papermaking. The black liquor contains lignin, cellulose, volatile organic acids, etc., which is odorous and highly polluting.

Superconducting high gradient magnetic force
The high-gradient magnetic separation and purification technology is a new method for treating wastewater. Since it does not generate impurities such as flocculation, it is feasible to treat a large amount of wastewater in a short time.
Scientific and technical personnel from the Department of Energy and Environmental Engineering at the University of Osaka, Japan, studied the use of magnetic separation systems to treat paper mill wastewater. The test workshop treated papermaking wastewater at 2000 t/d and carried out the cyclic operation to achieve a chemical oxygen demand (CODCr) of <40 mg/L in the water after magnetic separation. The superconducting magnetic tube NbTi spiral tube has a length of 680 mm and an inner diameter of 400 mm.
The system consists mainly of a mixing tank (magnetic seed tank, seed crystals for organic matter, pulp and dye), a sedimentation tank and a superconducting magnetic tube. Through the magnetic force in the superconducting magnetic separation tube, the magnetic particles and organic polymers such as pulp and pigment are captured, the magnetic short fibers and the filler are floated, and a part of the magnetic short fibers and the filler are deposited by gravity sedimentation, and are deposited in the sedimentation tank. Helps reduce the amount of short fibers and fillers when circulating water passes through a magnetic tube. The system has been successfully operated for several months and has achieved satisfactory results.

Paper Wastewater Treatment Method
The papermaking wastewater mainly comes from the two production processes of pulping and papermaking in the paper industry. Pulping is to separate the fibers in the plant raw material, make a slurry, and then bleach, this process will produce a large amount of papermaking wastewater; papermaking is to dilute, shape, press, and dry the slurry to make paper, this The process is also prone to papermaking wastewater.
The papermaking wastewater produced by pulping is the most polluted. The waste water discharged during washing is dark brown, called black water. The concentration of pollutants in black water is very high, and the BOD is as high as 5-40 g/L, which contains a large amount of fiber, inorganic salt and pigment. The papermaking wastewater discharged from the bleaching process also contains a large amount of acid-base substances. The papermaking wastewater discharged from the paper machine, called white water, contains a large amount of fibers and fillers and compounds added during the production process.
Papermaking wastewater treatment should focus on improving the recycling rate, reducing water consumption and wastewater discharge, and actively exploring various reliable, economical and wastewater treatment methods that can make full use of the useful resources in wastewater. For example, the flotation wastewater treatment method can recover fibrous solid materials in white water, the recovery rate can reach 95%, and the clarified water can be reused. The combustion wastewater treatment method can recover sodium hydroxide, sodium sulfide, sodium sulfate and organic substances in black water. Other sodium salts. The neutralization wastewater treatment method adjusts the pH value of the wastewater; the coagulation sedimentation or flotation method can remove the suspended solids in the wastewater; the chemical precipitation method can decolorize; the biological treatment method can remove the BOD, and is effective for the kraft paper wastewater; the wet oxidation process treats the sulfite pulp Wastewater is more successful. In addition, there are also papermaking wastewater treatment methods such as reverse osmosis, ultrafiltration and electrodialysis at home and abroad.

Paper Wastewater Treatment Agent
Polyacrylamide
Polyacrylamide is widely used as a residence agent, filter aid, leveling agent, etc. in the papermaking field. Its function is to improve the quality of the paper, improve the dewatering performance of the slurry, increase the retention of fine fibers and fillers, reduce the consumption of raw materials and environmental pollution. The effectiveness of polyacrylamide in papermaking depends on its average molecular weight, ionic properties, ionic strength, and activity of other copolymers. Non-ionic polyacrylamide is mainly used to improve the filterability of pulp, increase the strength of dry paper, and increase the retention of fibers and fillers; anionic copolymers are mainly used as dry and wet enhancers and residence agents for paper; cationic copolymerization The material is mainly used for papermaking wastewater treatment and filter aid, and also has a good effect on increasing the retention rate of the filler. In addition, polyacrylamide is also used in papermaking wastewater treatment and fiber recycling.

Aluminium Sulfate
Aluminum sulfate is very soluble in water, aluminum sulfate cannot be dissolved in pure sulfuric acid (only coexisting), and is dissolved in water in sulfuric acid solution together with sulfuric acid, so the solubility of aluminum sulfate in sulfuric acid is the solubility of aluminum sulfate in water. The precipitated at room temperature contains 18 molecules of crystal water, which is aluminum sulfate 18 water, and industrially produces mostly aluminum sulfate 18 water. Containing 51.3% of anhydrous aluminum sulfate, it does not self-dissolve (dissolved in its own crystal water) even at 100 °C. It is not easy to weather and lose crystal water. It is relatively stable, heating will lose water, and high temperature will decompose into oxides of alumina and sulfur. Heating to 770 ° C begins to decompose into alumina, sulfur trioxide, sulfur dioxide and water vapor. Soluble in water, acid and alkali, insoluble in ethanol. The aqueous solution is acidic. After hydrolysis, aluminum hydroxide is formed. The aqueous solution boils for a long time to form basic aluminum sulfate. Industrial products are gray-white flakes, granules or lumps. They are light green due to low iron salts and yellowish due to oxidation of low-cost iron salts. The crude product is a grayish white fine crystal structure porous. Non-toxic, dust can irritate the eyes.

Sodium metabisulfite
Sodium metabisulfite is a white or yellow crystalline powder or small crystal with a strong SO2 odor, a specific gravity of 1.4, soluble in water, and the aqueous solution is acidic. When it is in contact with a strong acid, it releases SO2 to form a corresponding salt. When it is left in the air, it oxidizes. It is Na2S2O6, so the product cannot be stored for a long time. Above 1500C, SO2 is decomposed.
Sodium metabisulfite is used for the production of insurance powder, sulfamethazine, dipyridamole, caprolactam, etc., as well as the purification of chloroform, phenylpropane sulfone and benzaldehyde. The photographic industry is used as a fixative for the fixer. The perfume industry is used to produce vanillin. Used as a preservative for brewing industry, a rubber coagulant and a bleaching agent for cotton bleaching. Organic intermediates, dyes, and tanning are used as reducing agents for electroplating, wastewater treatment in oil fields, and as a mineralizer for mines. Industrially used in printing and dyeing, organic synthesis, printing, tanning, pharmaceutical and other departments; as a preservative, bleaching agent, loosening agent in food processing. (Printing and printing, photography, etc.), used as a bleaching agent, mordant, reducing agent, rubber coagulant, also used in organic synthetic pharmaceuticals and spices.

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