污泥性質(zhì)和廢水處理的影響外文翻譯

1、絮凝：污泥性質(zhì)和廢水處理的影響 摘要 進(jìn)行研究，以確定在激活的絮凝作用污泥單元過程。實(shí)驗(yàn)室和完整的大型研究顯示，絮凝最重要的，在于確定沉淀，脫水，污水和消化污泥特性（活性污泥屬性），并可能涉及到的所有進(jìn)程的功能是至關(guān)重要的。在這些研究中，結(jié)果表明，二價(jià)陽離子，如鈣和鎂改善活性污泥的性質(zhì)，而單價(jià)陽離子如如鈉，鉀和銨離子，不利于這些屬性。 “二價(jià)陽離子通過銜接機(jī)制，促進(jìn)負(fù)責(zé)絮凝帶負(fù)電荷的生物大分子（主要是蛋白質(zhì)和多糖）。結(jié)果發(fā)現(xiàn)，氧化鐵起著重大作用，在活性污泥的絮凝和決心通過鐵和生物大分子之間的表面相互作用的性質(zhì)。氧化鐵有效地消除從凝固的膠體溶液聚合物和空調(diào)的研究。這項(xiàng)研究包括鉀的實(shí)驗(yàn)評估影響沉降

2、和脫水性能和銨離子，鎂的影響沉降性能;影響鈉，鉀，鈣和鎂的廢水質(zhì)量;固體停留時(shí)間，對出水水質(zhì)的影響;絮狀物評估在有氧和高溫消化的屬性。一個(gè)絮狀物模型中提出鈣，鎂，鐵絮凝的功能是很重要曝氣池，沉淀池，脫水設(shè)備和好氧或厭氧沼氣池。 結(jié)果表明，活性污泥絮狀物性能的影響廢水處理效率。關(guān)鍵詞：陽離子，活性污泥，沉淀，脫水，鎂，銨。前言 活性污泥是由微生物財(cái)團(tuán)和胞外聚合物和二價(jià)陽離子（手冢，1969年形成了矩陣一起舉行的有機(jī)和無機(jī)粒子;諾瓦克和豪根，1981年埃里克森和alm，1991; bruus等，1992;希金斯和諾瓦克，1997年，b）。 bruus等人。 （1992年）和希金斯和諾瓦克（1997

3、年b）表明，多余的單價(jià)陽離子可引起中絮狀物的惡化結(jié)構(gòu)和沉降性能。觀察與二價(jià)陽離子的增加沉降性能的改善。 許多工業(yè)系統(tǒng)需要高純度的進(jìn)水。因此，除了規(guī)定的化學(xué)品在工業(yè)過程和廢水預(yù)處理的廢水進(jìn)入激活污泥盆地的陽離子組成。這些廢水通常會在一些陽離子缺陷，將包含他人的過多。單價(jià)離子的增加導(dǎo)致活性污泥脫水性能的惡化，而二價(jià)離子的增加已被證明可以改善活性污泥脫水性能希金斯和諾瓦克，1997，（二）已被觀察到。這些意見進(jìn)行了實(shí)驗(yàn)室和工業(yè)系統(tǒng)中活性污泥絮體。希金斯和諾瓦克（1997年b）評估從七個(gè)工業(yè)設(shè)施的陽離子和發(fā)現(xiàn)，時(shí)的上chargeequivalent的基礎(chǔ)上的單價(jià)超過二價(jià)陽離子比（m / d）2，在脫水

4、性能（具體到過濾阻力）發(fā)生惡化。最經(jīng)常發(fā)現(xiàn)添加燒堿的ph值控制在行業(yè)的高m/ d比值的相關(guān)問題。因此，鈉離子是游離在這些系統(tǒng)中的單價(jià)離子輸入。本研究的目的是評估nonfilamentous沉降和脫水的問題進(jìn)行鑒定的潛力，通過篩選陽離子，到達(dá)實(shí)驗(yàn)室或田間試驗(yàn)的策略，找出并解決相關(guān)的問題（s）。工業(yè)體系研究含有高濃度的鈉離子（平均為2000毫克/升）加入氫氧化鈉預(yù)處理步驟，以防止醋酸的揮發(fā)。廢物流中的主要成分是醋酸。進(jìn)水cod為10000毫克/升的順序?；钚晕勰嗟膒h值8.8。工業(yè)廢水處理系統(tǒng)被發(fā)現(xiàn)有極端貧困的沉降和脫水性能由于高濃度的鈉離子。最初進(jìn)行化驗(yàn)，以評估為二價(jià)陽離子的可能的應(yīng)用領(lǐng)域，以實(shí)

5、現(xiàn)較低的m / d比值，其次是活性污泥性質(zhì)的每周監(jiān)測的田間試驗(yàn)的戰(zhàn)略。提出了短期和長期的解決方案。結(jié)論1離子是直接關(guān)系到沉降和脫水性能的變化。該實(shí)驗(yàn)室的研究是一個(gè)有效的田間試驗(yàn)的序幕。實(shí)驗(yàn)室可處理的研究表明鈣此外田間試驗(yàn)的不適應(yīng)。進(jìn)一步的實(shí)驗(yàn)室研究表明，鎂會是一個(gè)合適的二價(jià)陽離子替代。田間試驗(yàn)表明，在絮狀密度增加鎂離子的改善。前一個(gè)時(shí)間差可以預(yù)計(jì)實(shí)現(xiàn)沉降性能的改進(jìn)。雖然陽離子交換可能發(fā)生，可能需要更換的污泥絮體的完整的二價(jià)金屬離子被完全納入到污泥絮。鎂離子提高脫水性能的實(shí)驗(yàn)研究，在更大程度上比在實(shí)地試驗(yàn)，可能是由于在實(shí)驗(yàn)室研究中使用的二價(jià)離子濃度較高的表現(xiàn)。田間試驗(yàn)與增長中的可溶性銨離子的脫水

6、性能?？磥恚@離子活性污泥絮體在類似的方式，以鈉離子相互作用，導(dǎo)致可溶性蛋白的釋放和脫水性能惡化。復(fù)雜的變化，同時(shí)在幾個(gè)陽離子可使其具有挑戰(zhàn)性的隔離沉降和脫水性能變化的原因?？紤]對他們的影響力，解決anddewatering屬性時(shí)，需要考慮不同的陽離子和絮狀物（成絮狀物的摻入陽離子）之間的互動(dòng)和彼此之間（陽離子交換）。硫酸鎂除了被證明是非常有益的沉降性能改善。如果需要進(jìn)一步改善，長期戰(zhàn)略是必不可少的。 對于工業(yè)設(shè)施，它可能是有用的，以探索其他替代品的ph值控制。在曝氣池硝化的成就可能會進(jìn)一步改善活性污泥絮體的屬性。硝化活性污泥性能的影響，需要進(jìn)一步探索。結(jié)論2實(shí)驗(yàn)室和現(xiàn)場進(jìn)行了研究，評估調(diào)節(jié)選

7、項(xiàng)atad污泥脫水。本研究的目的是探討機(jī)會，以減少化學(xué)空調(diào)費(fèi)用。研究，進(jìn)行陽離子聚合物和無機(jī)調(diào)理組合（三氯化鐵或明礬）陽離子聚合物。這項(xiàng)研究表明，如氯化鐵和明礬等無機(jī)空調(diào)非常有效地降低空調(diào)的化學(xué)要求，從而減少經(jīng)營成本，為atads。無機(jī)空調(diào)消除陰離子biocolloids有效。之前實(shí)現(xiàn)電荷中去除的陰離子biocolloids的發(fā)生。去除這些陰離子biocolloids的可能是通過鐵羥基礦物相關(guān)降水量為混凝研究中觀察到。與陽離子聚合物的調(diào)理機(jī)制是通過電荷中和。前凝血與無機(jī)調(diào)理污泥將減少溶液中的負(fù)電荷，從而消除了一些陽離子聚合物的需求。不同的機(jī)制導(dǎo)致不同的空調(diào)需求。氯化鐵和明礬是更有效地消除較大規(guī)

8、模的蛋白質(zhì)和多糖分子（大于30k）。無機(jī)混凝劑，也更有效的生物聚合物和化學(xué)需氧量釋放更大。應(yīng)考慮使用無機(jī)化學(xué)混凝劑，在消化過程中釋放大量的蛋白質(zhì)，多糖和cod時(shí)發(fā)生。其次是用明礬和陽離子高分子絮凝劑大大降低空調(diào)化學(xué)學(xué)院站成本的空調(diào)溫曝氣相結(jié)合。成本相近或低于，需要溫厭氧消化。 濾液回收化學(xué)需氧量明顯減少，廠內(nèi)發(fā)泡大學(xué)是很大程度上消除了采用組合的中溫曝氣和利用明礬。bioflocculation: implications for activated sludge properties and wastewater treatment abstract studies were conducte

9、d to determine the role of bioflocculation in the activated.sludge unit processes. laboratory and full-scale studies revealed that bioflocculation is important in determining settling, dewatering, effluent and digested sludge properties(activated sludge properties) and may be vital to the function o

10、f all processes related to the above properties. in these studies, it was shown that divalent cations such as calcium and magnesium improved activated sludge properties, whereas monovalent cations such as sodium, potassium and ammonium ions were detrimental to these properties. the divalent cations

11、promoted bioflocculation through charge bridging mechanisms with negatively charged biopolymers (mainly protein and polysaccharide). it was found that oxidized iron plays a major role in bioflocculation and determination of activated sludge properties through surface interactions between iron and bi

12、opolymers. oxidized iron was effective in removing colloidal biopolymers from solution in coagulation and conditioning studies. the research included experiments evaluating effects of potassium and ammonium ions on settling and dewatering properties; effects of magnesium on settling properties; effe

13、cts of sodium, potassium, calcium and magnesium on effluent quality; effect of solids retention time on effluent quality; and evaluation of floc properties during aerobic and thermophilic digestion. a floc model is proposed in which calcium, magnesium and iron are important to bioflocculation and th

14、e functionality of aeration tanks, settling tanks, dewatering equipment and aerobic or anaerobic digesters. it is shown that activated sludge floc properties affect wastewater treatment efficiency.keywords：cation, activated sludge, settling, dewatering, magnesium, ammonium.introduction activated slu

15、dge is comprised of microbial consortiums and organic and inorganic particles held together in a matrix formed by exocellular polymers and divalent cations (tezuka, 1969; novak and haugan, 1981; eriksson and alm, 1991; bruus et al., 1992; higgins and novak, 1997a, b). bruus et al. (1992) and higgins

16、 and novak(1997b) have shown that excess monovalent cations can cause a deterioration in flocstructure and settling properties. improvements in settling properties were observed with an increase in divalent cations. many industrial systems require influent water of high purity. therefore, the additi

17、on of chemicals during the industrial process and wastewater pretreatment dictate the cationic composition of the wastewater entering the activated sludge basins. often these wastewaters will be deficient in some cations and will contain an overabundance of others. an increase in monovalent ions has

18、 been observed to cause a deterioration in dewatering properties in activated sludge, whereas an increase in divalent ions has been shown to improve activated sludge dewatering properties (higgins and novak, 1997a, b). these observations were made for activated sludge flocs in laboratory and industr

19、ial systems. higgins and novak (1997b) evaluated the cations from seven industrial facilities and found that, when the monovalent to divalent cation ratio (m/d) on a chargeequivalent basis exceeded 2, deterioration in dewatering properties (specific resistance to filtration) occurred. the problems a

20、ssociated with a high m/d ratio were most often found in the industries that added caustic for ph control. therefore, sodium ions were the prevalent monovalent ion input in these systems.the purpose of this study was to evaluate the potential for identification of nonfilamentous settling and dewater

21、ing problems through screening of cations, to arrive at a strategy for laboratory or field trials, and to identify and address the associated problem(s).the industrial system studied contained a high concentration of sodium ions(average of 2,000 mg/l) added as sodium hydroxide in the pretreatment st

22、ep to prevent volatilization of acetic acid. the major component in the waste stream was acetic acid. the influent cod was in the order of 10,000 mg/l. the activated sludge had a ph of 8.8. the industrial wastewater treatment system was found to have extremely poor settling and dewatering properties

23、 due to a high concentration of sodium ions. laboratory tests were initially conducted to evaluate a strategy for possible field application of divalent cations to achieve a lower m/d ratio, followed by field trials of weekly monitoring of activated sludge properties. short and long term solutions w

24、ere proposed.conclusions1 cations were directly related to changes in settling and dewatering properties. the laboratory study was an effective prelude to field trials. the laboratory treatability study indicated the unsuitability of calcium addition for the field trial. the laboratory research furt

25、her showed that magnesium would be a suitable divalent cation alternative. field trials demonstrated an improvement in floc density associated with an increase in magnesium ions. a time lag could be anticipated prior to achieving improvements in settling properties. although cation exchange may take

26、 place, a complete replacement of sludge flocs may be required for the divalent ions to be completely incorporated into the sludge floc. magnesium ions improved dewatering properties in the laboratory study to a greater extent than demonstrated in the field trials, probably due to the higher concent

27、ration of the divalent ion used in the laboratory study. the field trials linkeddewatering properties to an increase in the soluble ammonium ions. it appears that ammonium ions interact with activated sludge flocs in a manner similar to sodium ions, causing a release in soluble proteins and a deteri

28、oration in dewatering properties.complex variations in several cations simultaneously may make it challenging to isolate the cause for changes in settling and dewatering properties. interaction between different cations and the floc (cation incorporation into the floc) and amongst themselves (cation

29、 exchange) need to be taken into account when considering their influence on settling anddewatering properties. the addition of magnesium sulfate proved to be extremely beneficial in improving settling properties. if further improvements are required, long term strategies are essential. for the indu

30、strial facility, it may be useful to explore other alternatives for ph control. achievement of nitrification in the aeration basin may further ameliorate activated sludge floc properties. the effect of nitrification on activated sludge properties require further exploration.conclusions2laboratory an

31、d field studies were conducted to evaluate the conditioning optionsfor the dewatering of atad biosolids. the objective of this study was to investigate opportunities to reduce chemical conditioning costs. studies were conducted using cationic polymer and a combination of inorganic conditioners (ferr

32、ic chloride or alum)and cationic polymer. this study indicated that inorganic conditioners such as ferric chloride and alumwere very effective in reducing conditioning chemical requirements, thereby reducingoperation costs, for atads. the inorganic conditioners were effective in removing anionic biocolloids. removal of the anionic biocolloids occurred prior to achieving charge neutralization. the removal of these anionic biocolloids may be through ferric-hydroxy mineral associated precipitation as observed in the coagulation study. the conditioning mechanisms as