食品行業廢水處理

 

　　摘要：食品工業的內容極其復雜，包括制糖、釀造、肉類、乳品加工等生產過程，所排出的廢水都含有機物，具有強的耗氧性，且有大量懸浮物隨廢水排出。動物性食品加工排出的廢水中還含有動物排泄物、血液、皮毛、油脂等，并可能含有病菌，因此耗氧量很高，比植物性食品加工排放的廢水的污染性高得多。因此食品工業廢水對環境和人類影響都很大，需要經過一定的技術將其處理凈化再排放。

Abstract: The content of the food industry is extremely complex, including the production processes of sugar making, brewing, meat, dairy processing, etc and the discharged wastewater contains organic matter, which has strong oxygen consumption and a large amount of suspended matter discharged with the wastewater. The wastewater discharged from the processing of animal also contains animal excrement, blood, fur, fat, etc., and may contain pathogenic bacteria, so the oxygen consumption is very high, and the pollution is higher than that of the wastewater discharged from the processing of plant food. Therefore, the wastewater from the food industry has a great impact on the environment and human beings, it needs to be treated and purified by certain technology before it is discharged.

　　關鍵詞：食品 食品工業廢水 處理方法

Keywords: food; food industry wastewater; treatment method

　　1 概述：

1 Overview:

　　食品工業包括肉類加工，水產加工乳品加工，罐頭生產，釀造，制糖等諸多工業，因此食品工業原料廣泛，制品種類繁多，排出廢水的水量、水質差異很大。與其他工業廢水的差異是食品工業廢水一般不含重金屬，農藥等有害物質。但其BOD、COD等一般會偏高。由于食品工業所用的原料大多數為人體能消化的有機物質。因此食品工業廢水的可生化性一般都較好。

The food industry includes many industries such as meat processing, aquatic product processing, dairy processing, canning production, brewing, sugar refining, etc., the raw materials of the food industry are extensive, the types of products are numerous, and the amount and quality of wastewater discharged vary greatly. The difference with other wastewater is that food industry wastewater generally does not contain harmful substances such as heavy metals and pesticides. However, its BOD, COD, etc., are generally high. most of the raw materials used in the food industry are organic substances that can be digested by the human body, the biodegradability of food industry wastewater is good.

　　廢水中主要污染物有：(1)漂浮在廢水中固體物質，如菜葉、果皮、碎肉、禽羽等;(2)懸浮在廢水中的物質有油脂、蛋白質、淀粉、膠體物質等;(3)溶解在廢水中的酸、堿、鹽、糖類等：(4)原料夾帶的泥砂及其他有機物等;(5)致病菌毒等。食品廢水包括酒精、啤酒、味精、淀粉、乳糖、檸檬酸、蔬菜加工及各種軟飲料加工過程中排出的廢水，如果不對廢水進行及時的處理則會對環境造成極大的污染。

The main pollutants in wastewater are: (1) solid substances floating in wastewater, such as vegetable leaves, fruit peels, minced meat, poultry feathers, etc.; (2) substances suspended in wastewater, such as oil, protein, starch, colloidal substances, etc.; (3) acids, alkalis,, sugars, etc. dissolved in wastewater: (4) mud and sand and other organic matter carried by raw materials, etc.; (5) pathogenic bacteria and, etc. Food wastewater includes wastewater discharged during the production of alcohol, beer, monosodium glutamate, starch, lactose, citric acid, vegetable processing various soft drinks, which will cause great pollution to the environment if it is not treated in time.

　　食品工業廢水的特點是有機物質和懸浮物含量高，易腐敗，一般無大的毒性，水質水量隨季節變化，高濃度廢水多。其危害主要是使水體富營養化，以致引起水生動物和魚類死亡，促使水底沉積的有機物產生臭味，惡化水質，污染環境。食品工業廢水處理除按水質特點進行適當預處理外，一般均宜采用生物處理。如對出水水所要求很高或廢水中有機物含量很高，可采用兩級曝氣池或兩級生物濾池，或多級生物轉盤，或聯合使用兩種生物技術，也可采用厭氧——需氧串聯的生物處理系統。

The characteristics of food industry wastewater are high content of organic matter and suspended solids, easy to corrupt, generally no large toxicity, water quality and volume change with the season, and high concentration of wastewater. Its hazards mainly include eutrophication of water bodies, which can lead to the death of aquatic animals fish, promote the production of malodorous organic matter deposited at the bottom of the water, deteriorate water quality, and pollute the environment. For the treatment food industry wastewater, in addition to appropriate pretreatment according to the characteristics of water quality, biological treatment is generally suitable. If the requirements for effluent are very high the content of organic matter in the wastewater is very high, two-stage aeration tank or two-stage biological filter can be used, or multi-stage biological disc, or use of two biological technologies, or anaerobic-aerobic series biological treatment system can be used.

2 國內外概況

 2 Domestic and foreign situation

　　中國對食品廢水污染的治理與西方發達國家相比起步較晚，在借鑒國外處理技術經驗的基礎上，以國家科技攻關課題為平臺，引進和開發了大量的食品廢水處理新技術，某些項目已達到高水平。這些新技術的投產運行為緩解中國嚴峻的水污染現狀，改善水環境發揮了至關重要的作用。

The control of food wastewater pollution in China started late compared to western developed countries. Based on the experience of foreign treatment technology, a large number of food wastewater treatment technologies have been introduced and developed with the national science and technology research project as the platform. Some projects have reached a high level. The production and operation these new technologies have played a crucial role in alleviating the severe water pollution situation in China and improving the water environment.

　　中國環境狀況公報顯示，2008年全國地表水污染依然嚴重，全國七大水系407個國家監控斷面中，Ⅰ~Ⅲ類、Ⅳ~Ⅴ類、劣Ⅴ類水質的斷面比例分別為49.9%、26.5%和23.6%，七大水系水質總體為中度污染，浙閩區河流水質為輕度污染，西北諸河水質為優，西南諸河水質良好，湖泊(水庫)富營養化問題突出;近岸海域水質總體為輕度污染。而其中食品工業廢水占很大一部分比例。

The China Environment Bulletin shows that the pollution of surface water in China was still serious in 2008. Among the 407 monitoring sections in the seven major water systems, the proportions of sections with water quality of Class I to III, Class IV to V, and worse than Class V were49.9%, 26.5%, and 23.6%, respectively. The overall water quality of the seven major water systems was moderately polluted the water quality of rivers in the Zhejiang-Fujian region was lightly polluted, the water quality of rivers in the northwest region was excellent, the water quality rivers in the southwest region was good, and the problem of eutrophication in lakes (reservoirs) was prominent; the water quality of the near-sh sea area was generally lightly polluted. Among them, the wastewater from the food industry accounted for a large proportion. 

　　我國特別是在中小城鎮中分布著大量的食品加工企業,這些企業的現代化程度和生產規模日益提高,但是產生的廢水水質惡劣,廢水量不斷增加,對環境危害很嚴重。食品工業包括飲料工業是耗水大戶,這些耗用的水僅少部分用于食品生產本身,大部分是用于食品生產過程洗滌和清潔的,因此可以將這些廢水加以回收利用。基本上以糧食為主要原料的發酵工業所產生的污染物主要是由于糧食未被利用造成的,因此,排入水環境的污染物絕大部分是具有回收價值的產品和副產品。

A large number of food processing enterprises are distributed in China, especially in small and medium-sized cities and towns. The modernization degree and production of these enterprises are getting higher and higher, but the water quality of the produced wastewater is poor, and the amount of wastewater is increasing continuously, which is very harmful the environment. The food industry, including the beverage industry, is a major water consumer. Only a small part of the water consumed is used for food production itself, most of it is used for washing and cleaning in the food production process. Therefore, these wastewaters can be recovered and reused. The pollutants produced by the fermentation, which basically uses grain as the main raw material, are mainly due to the fact that the grain is not utilized. Therefore, most of the pollutants discharged into the environment are products and by-products with recovery value.

　　現代廢水處理技術分三類：物理處理法，化學處理法，生物化學處理法。物理處理法包括：沉淀法，過濾法，離心分離法，浮選法;化學處理法包括：混凝法，中和法，氧化還原法，電解法，萃取法，吹脫法，吸附法，電滲析法，反滲透法;生物化學處理法：活性污泥法，生物膜法氧化塘法，土地處理法。另外還有一些新技術，如酶促降解法，高效降解菌的應用，超聲波技術的應用，磁分離法，超臨界水氧化法，電極生物膜法等。

Modern wastewater treatment technology is divided into three categories: physical treatment method, chemical treatment method, and biochemical treatment method. The physical treatment method includes precipitation method, filtration method, centrifugal separation method, and flotation method; the chemical treatment method includes: coagulation method, neutralization method, oxidation-reduction, electrolysis method, extraction method, stripping method, adsorption method, electrodialysis method, and reverse osmosis method; biochemical treatment method: activatedudge method, biofilm method, oxidation pond method, and land treatment method. In addition, there are some new technologies, such as enzymatic degradation method, the of efficient degradation bacteria, the application of ultrasound technology, magnetic separation method, supercritical water oxidation method, and

　　3廢水處理

3 Wastewater treatment

　　3.1衡量廢水污染程度及廢水特性的指標：生物需氧量BOD，化學需氧量BOD，總懸浮固體TSS，揮發性懸浮固體VSS，營養物，酸度和堿度，溫度，有毒物質等。

3.1 Indicators for measuring the degree of wastewater pollution and the characteristics of wastewater: biochemical oxygen demand (BOD), chemical oxygen demand (COD total suspended solids (TSS), volatile suspended solids (VSS), nutrients, acidity and alkalinity, temperature, toxic substances, etc.

　　3.2物理處理方法：物理處理法是指應用物理作用改變廢水成分的處理方法。用于食品工業廢水處理法有篩濾、撤除、調節、沉淀、氣浮、離心分離、過濾、微濾等。前五種工藝多用于預處理或一級處理，后三種主要用于深度處理。

3.2 Physical treatment methods: Physical treatment methods refer to the treatment methods that apply physical effects to change the composition of wastewater. The treatment methods for food industry wastewater include screening, removal, regulation, precipitation, air flotation, centrifugal separation, filtration, microfiltration, etc. The first five processes are used for pretreatment or primary treatment, and the last three are mainly used for advanced treatment.

　　3.2.1篩濾

3.2.1 Sieving

　　篩濾是預處理中使用廣泛的一種方法。主要作用是從廢水中分離出較粗的分散性懸浮固體物。使用的設備有格柵和格篩。格柵攔截較粗的懸浮固體，起作用是保護水泵和后續處理設備。

Screening is a widely used method in pretreatment. Its main function is to separate coarser dispersed suspended solids from wastewater. The equipment used includes grids screens. Grids intercept coarser suspended solids, and their function is to protect pumps and subsequent treatment equipment.

　　3.2.2撤除

 

　　某些食品工業廢水中含有大量的油脂，這些油脂必須在進入生物處理工藝前予以除去，否則會造成管道、水泵和一些設備的堵塞，也會對生物處理工藝造成影響。另外油脂除去并回收有較大經濟價值。

Some food industry wastewater contains a large amount of oil, which must be removed before entering the biological treatment process, otherwise it will cause blockage of, pumps and some equipment, and also have an impact on the biological treatment process. In addition, the removal and recovery of oil has great economic value

　　廢水中油脂可分為游離漂浮狀和乳化狀兩類。通常隔油池除去漂浮狀油脂，去除率可達90%以上。如處理中設有調節池或沉淀池，可節省投資和占地。

The oil in wastewater can be divided into two categories: free floating and emulsified. Generally, the oil separation tank removes the floating oil, with removal rate of more than 90%. If there is a regulating tank or sedimentation tank in the treatment process, it can save investment and land

　　3.2.3調節

3.2.3 Adjustment

　　對于稅制水量變化幅度大的食品工業廢水，設置調節池對廢水的水質和水量進行調節。

For the wastewater of food industry with large changes in tax system water volume, a regulating tank is set up to regulate the water quality and water volume of wastewater.

　　3.2.4沉淀

3.2.4 Precipitation

　　沉淀是用來除去原廢水中無機固體物和有機固體物，以及分離生物處理工藝中的固相和液相。用沉砂池除去原廢水中的無機固形物;用初沉池除去原廢水中的有機固形物;用二沉池分離生物處理工藝中的生物相和液相，沉砂池一般設在格柵和格篩之后。為了在清除中避免廢水中有機物固體在沉砂池產生沉淀可采用曝氣沉砂池。采用初沉池可降低后續工作負擔。按池中水流方向分平流沉淀池，豎流沉淀池，輻流沉淀池。

Sedimentation is used to remove inorganic and organic solids from raw wastewater, as well as to separate the solid and liquid phases in treatment processes. Inorganic solids in raw wastewater are removed using a sand trap; organic solids in raw wastewater are removed using a primary sedimentation tank; and the biological liquid phases in biological treatment processes are separated using a secondary sedimentation tank. Sand traps are generally located after the bar screen and screen. To avoid the precipitation of organic in the sand trap during removal, an aerated sand trap can be used. The use of a primary sedimentation tank can reduce the burden of subsequent work. Sedation tanks can be divided into horizontal flow sedimentation tanks, vertical flow sedimentation tanks, and radial flow sedimentation tanks according to the direction of water flow in the.

　　3.2.5氣浮

3.2.5 Air flotation

　　氣浮主要用于除去廢水中的乳化油、表面活性物質和其他懸浮固體。有真空式，加壓溶氣式和板式的。在廢水進入氣浮池前，在水中投入化學混凝劑或助凝劑，可提高去除率。

Dissolved air flotation is mainly used to remove emulsified oil, surfactants and other suspended solids from wastewater. There are vacuum type,urized dissolved air type and plate type. The removal efficiency can be improved by adding chemical coagulants or flocculants to the water before the wastewater the dissolved air flotation tank.

　　3.3化學處理法

 

　　化學處理法是指應用化學原理和化學作用將廢水中的污染物成分轉化為無害物質，使廢水得到凈化。污染物在經過化學處理過程后改變了化學本質，處理過程中總是伴隨著化學變化。用于食品廢水處理法有中和、混凝、電解、氧化還原、離子交換、膜分離法等。

Chemical treatment method refers to the application of chemical principles and chemical effects to convert pollutant components in wastewater into harmless substances, so that wastewater can purified. Pollutants change their chemical nature after going through the chemical treatment process, and chemical changes always accompany the treatment process. The treatment methods used for food wastewater neutralization, coagulation, electrolysis, oxidation-reduction, ion exchange, membrane separation, etc.

　　3.3.1混凝法

3.3.1 Coagulation method

　　混凝法是主要化學處理法，不能單獨使用，需與物理處理工藝中的沉淀、澄清法或氣浮法結合使用，構成混凝沉淀或混凝氣浮。

Coagulation is the main chemical treatment method, which can not be used alone, but must be combined with precipitation, clarification method or air flotation method physical treatment process, forming coagulation precipitation or coagulation air flotation.

　　對于一些膠體顆粒較小或膠體溶液，難以發生沉淀的廢水加入混凝劑，使其形成易于沉淀的大顆粒而除去。

For some wastewater with smaller colloidal particles or colloidal solutions, it is difficult to precipitate. Coagulants are added to make them form particles that are easy to precipitate and remove.

　　3.3.2氧化還原

3.3.2 Oxidation-reduction

　　氧化還原是轉化廢水中污染物的有效方法，廢水中有機物和無機物，通過化學反應被氧化或還原為微毒或無毒物質，或者轉化成容易與水分分離的形態，從而達到處理的目的。

Redox is an effective method to transform pollutants in wastewater, in which organic and inorganic substances in wastewater are oxidized or reduced into micro-toxic non-toxic substances, or are converted into forms that are easy to separate from water through chemical reactions, thus achieving the purpose of treatment.

　　3.3.3離子交換

3.3.3 Ion exchange

　　離子交換主要是利用離子交換劑對水中存在的有害離子進行交換取去除的方法。

Ion exchange is a method of removing harmful ions from water by exchanging them with other ions using ion exchange agents.

　　3.4生物處理法

 

　　生物化學處理法是有機廢水處理系統中重要的過程之一。在食品工業廢水處理中，生物處理工藝分為好樣、厭氧、穩定塘、土地處理以及它們結合形成的各種各樣的組合工藝。生物法是主要的二級處理工藝，目的在于降解COD、BOD。

Biochemical treatment method is one of the important processes in the treatment system of organic wastewater. In the treatment of food industry wastewater, the biological treatment is divided into aerobic, anaerobic, stabilization pond, land treatment and a variety of combined processes formed by their combination. Biological method is the main secondary treatment process aiming at degrading COD, BOD.

　　好氧生物處理工藝根據所利用的微生物的生長形式分為活性污泥工藝和膜法工藝。前者包括傳統活性污泥法、階段曝氣法，生物吸附法、完全混合法、延時曝氣法、氧化溝、間歇活性污泥法等。后者包括生物濾池、塔式生物濾池、生物轉盤、活性生物濾池、生物接觸氧化法、好氧流化床等。

Aerobic biological treatment processes are divided into activated sludge processes and membrane processes according to the growth form of the microorganisms used. The former traditional activated sludge method, stage aeration method, biological adsorption method, complete mixing method, delayed aeration method, oxidation ditch, intermittent activated sludge method etc. The latter includes biological filter, tower biological filter, biological disc, activated biological filter, biological contact oxidation method, aerobic fluidized bed, etc.

　　厭氧生物處理法適用于食品工業廢水，主要原因是廢水中含容易生物降解的高濃度有機物，且無毒性。此外厭氧處理動力消耗低，產生的沼氣可作為能源，生成的剩余污泥量少，厭氧處理系統全部密閉，利于改善環境衛生。

Anaerobic biological treatment is suitable for food industry wastewater, mainly because the wastewater contains easily biodegradable high-concentration organic matter and is nonxic. In addition, anaerobic treatment has low power consumption, the produced biogas can be used as energy, the amount of excess sludge generated is, and the entire anaerobic treatment system is sealed, which is conducive to improving environmental sanitation.

　　4結論及展望

4 Conclusions and Prospects

　　通過上述各種有效的方法的使用和執行，使食品工業中的廢水得到了很大程度的改善，而且可以從中獲取其他物質，生產其他原料，而不是將廢物扔掉造成浪費，可以循環使用，減少不必要的損失和浪費。對水體污染，人類健康及其他各方的危害減小很多，但是各種處理方法所用的設備及耗能是一個很大的負擔，對于農村或中小型食品企業來講，大多數都無能力承擔，而且有些企業為了獲取更多利潤，不愿意在廢水處理方面投入過多的資金。另一方面國家的政策及有關法律法規不健全而且執行力度不夠，國家在這方面的投資也不多;再者現在食品企業有的人的素質低和覺悟不夠高，沒有看到廢水污染的嚴重性只顧自己的利益。

Through the use and implementation of the above various effective methods, the wastewater in the food industry has been greatly improved, and other substances can obtained from it, and other raw materials can be produced instead of throwing away waste and causing waste, which can be recycled to reduce unnecessary losses and waste. The pollution water bodies, human health and other parties have been greatly reduced, but the equipment and energy consumption used in various treatment methods are a great burden, and most of the or small and medium-sized food enterprises are unable to bear it, and some enterprises are unwilling to invest too much capital in wastewater treatment in order to obtain more profits. the other hand, the national policy and relevant laws and regulations are not perfect and the implementation is not strong enough, and the investment of the state in this aspect is much; moreover, the quality of some people in the food industry is low and the consciousness is not high enough, and they do not see the severity of wastewater pollution only care about their own interests.

　　以后如果國家能夠加大對此方面的投資，并建立完善的體系及法律制度，使這些檢測方法能夠得到廣泛普遍的使用，則食品工業的廢水處理狀況會得到很大改善，對水體污染影響極微，而且對人類身體健康影響會減小很多，食品企業也會從處理工程中獲取其他收獲，使資源得到循環利用，我國人均資源本來就很少，因此減輕了這方面的負擔。

If the state can increase investment in this area in the future, and establish a sound system and legal system, so that these detection methods can be used, the situation of wastewater treatment in the food industry will be greatly improved, and the impact on water pollution will be extremely small, and the impact on human health be greatly reduced. Food enterprises will also gain other benefits from the treatment project, so that resources can be recycled. China's per capita resources are very small, so will reduce the burden in this regard.

　　我相信若能將上述檢測方法普及，我國會得到很大的利益，不僅僅是金錢方面的，還會使全國人民受益。

I believe that if the above detection method can be popularized, our country will benefit greatly, not only in terms of money, but also for the of the people of the whole country.