處理工藝流程選擇,一般需考慮以下因素。
The following factors should be considered in the selection of treatment process.
1.廢水水質(zhì)生活污水水質(zhì)通常比較穩(wěn)定,一般的處理方法包括酸化、好氧生物處理、等。而工業(yè)廢水應(yīng)根據(jù)具體的水質(zhì)情況進(jìn)行工藝流程的合理選擇。特別需要指出的是,對于采用好氧生物處理工藝處理廢水來說,要注意廢水的可生化性,通常要求COD/BOD5>0.3,如不能滿足要求,可考慮進(jìn)行厭氧生物水解酸化,以提高廢水的可生化性,或是考慮采用非生物處理的物理或化學(xué)方法等。
1. Wastewater quality The quality of domestic sewage is generally stable, and the general treatment methods include acidification, aerobic biological treatment, disinfection, etc. Industrial wastewater should be reasonably selected according to the specific water quality. In particular, for the aerobic biological treatment process of wastewater, attention should be paid to the biodegradability of wastewater, which usually requires COD/BOD5> 0.3. If the requirements cannot be met, anaerobic biological hydrolysis acidification can be considered to improve the biodegradability of wastewater, or non biological treatment physical or chemical methods can be considered.
2.污水處理程度這是污水處理工藝流程選擇的主要依據(jù)。污水處理程度原則上取決于污水的水質(zhì)特征、處理后水的去向和污水所流入水體的自凈能力。但是目前,污水處理程度的確定主要依從的有關(guān)法律制度及技術(shù)政策的要求。通常環(huán)境管理部門是根據(jù)《污水綜合排放標(biāo)準(zhǔn)》及相關(guān)的行業(yè)排放標(biāo)準(zhǔn)來控制污水的排放濃度,一些經(jīng)濟發(fā)展水平較高的地區(qū)還規(guī)定了更為嚴(yán)格的地方排放標(biāo)準(zhǔn)。因此,無論是何種需要處理的污水,也無論是采取何種處理工藝及處理程度,都應(yīng)以處理系統(tǒng)的出水能夠達(dá)標(biāo)為依據(jù)和前提。按照法律、法規(guī)、政策的要求預(yù)防和治理水體環(huán)境污染。
2. The degree of sewage treatment is the main basis for the selection of sewage treatment process. In principle, the degree of sewage treatment depends on the water quality characteristics of sewage, the destination of treated water and the self purification capacity of the water body into which sewage flows. However, at present, the determination of sewage treatment degree is mainly subject to the requirements of relevant national legal systems and technical policies. In general, the environmental management department controls the discharge concentration of sewage according to the Integrated Wastewater Discharge Standard and relevant industrial discharge standards. Some regions with higher economic development level also set stricter local discharge standards. Therefore, no matter what kind of sewage needs to be treated, and no matter what treatment process and degree of treatment are adopted, it should be based on and premise that the effluent of the treatment system can reach the standard. Prevent and control water environment pollution according to the requirements of laws, regulations and policies.
3.建設(shè)及運行費用考慮建設(shè)與運行費用時,應(yīng)以處理水達(dá)到水質(zhì)標(biāo)準(zhǔn)為前提條件。在此前提下,工程建設(shè)及運行費用低的工藝流程應(yīng)獲得重視。此外,減少占地面積也是降低建設(shè)費用的重要措施。
3. When considering the construction and operation costs, the precondition for the construction and operation costs is that the treated water meets the water quality standards. On this premise, attention should be paid to the process flow with low construction and operation costs. In addition, reducing the floor area is also an important measure to reduce construction costs.
4.工程施工難易程度工程施工的難易程度也是選擇工藝流程的影響因素之一。如地下水位高,地質(zhì)條件差的地方,就不適宜選用深度大、施工難度高的處理構(gòu)筑物。
4. The degree of difficulty of engineering construction is also one of the factors affecting the selection of process flow. If the groundwater level is high and the geological conditions are poor, it is not suitable to select the treatment structures with large depth and high construction difficulty.
5.當(dāng)?shù)氐淖匀缓蜕鐣l件
5. Local natural and social conditions
當(dāng)?shù)氐牡匦巍夂虻茸匀粭l件也對廢水處理流程的選擇具有一定影響。如當(dāng)?shù)貧夂蚝?,則應(yīng)采用在采取適當(dāng)?shù)募夹g(shù)措施后,在低溫季節(jié)也能夠正常運行,并保證取得達(dá)標(biāo)水質(zhì)的工藝。
The local terrain, climate and other natural conditions also have a certain impact on the selection of wastewater treatment process. If the local climate is cold, the process that can operate normally in low temperature season after taking appropriate technical measures shall be adopted to ensure that the water quality reaches the standard.
當(dāng)?shù)氐纳鐣l件如原材料、水資源與電力供應(yīng)等也是流程選擇應(yīng)當(dāng)考慮的因素之一。
Local social conditions, such as raw materials, water resources and power supply, should also be considered in process selection.
5.污水的水量除水質(zhì)外,污水的水量也是影響因素之一。對于水量、水質(zhì)變化大的污水,應(yīng)考慮采用抗沖擊負(fù)荷能力強的工藝,或考慮設(shè)立調(diào)節(jié)池等緩沖設(shè)備以盡量減少不利影響。
5. In addition to water quality, the quantity of sewage is also one of the influencing factors. For sewage with large changes in water quantity and quality, the process with strong impact load resistance shall be considered first, or buffer equipment such as regulating tank shall be considered to minimize adverse effects.
6.7.處理過程是否產(chǎn)生新的矛盾
6.7. Whether there are new contradictions in the process of handling
污水處理過程中應(yīng)注意是否會造成二次污染問題。例如制藥廠廢水中含有大量有機物質(zhì)(如苯、甲苯、溴素等),在曝氣過程中會有有機廢氣排放,對周圍大氣環(huán)境造成影響;化肥廠造氣廢水在采用沉淀、冷卻處理后循環(huán)利用,在冷卻塔尾氣中會含有氰化物,對大氣造成污染;農(nóng)藥廠樂果廢水處理中,以堿化法降解樂果,如采用石灰做堿化劑,產(chǎn)生的污泥會造成二次污染;印染或染料廠廢水處理時,污泥的處置為關(guān)鍵考慮的問題。
Attention shall be paid to whether secondary pollution will occur during sewage treatment. For example, pharmaceutical wastewater contains a large amount of organic substances (such as benzene, toluene, bromine, etc.), and organic waste gas will be discharged in the process of aeration, which will affect the surrounding atmospheric environment; The waste water from the gasification of the fertilizer plant is recycled after sedimentation and cooling treatment. The tail gas of the cooling tower will contain cyanide, which will pollute the atmosphere; In the wastewater treatment of pesticide factory, dimethoate is degraded by alkalization method. If lime is used as alkalization agent, the sludge generated will cause secondary pollution; Sludge disposal is a key consideration in wastewater treatment of printing and dyeing or dye plants.
總之,污水處理流程的選擇應(yīng)綜合考慮各項因素,進(jìn)行多種方案的技術(shù)經(jīng)濟比較才能得出結(jié)論。
In a word, the selection of sewage treatment process should comprehensively consider various factors, and a conclusion can be drawn only through technical and economic comparison of various schemes.