硫化氫（H2S），一種具有臭雞蛋氣味的有毒惡臭氣體，在眾多工業(yè)活動(dòng)中均有出現(xiàn)。生物處理被認(rèn)為是處理這種惡臭氣體的最佳方法，主要因其低成本和高安全性。在眾多生物反應(yīng)器中，生物滴濾池（BTF）因其可控的操作參數(shù)和易排出的代謝產(chǎn)物而備受關(guān)注。然而，生物反應(yīng)器在運(yùn)行中常遇到生物量過度積累導(dǎo)致的高壓降問題，這不僅增加能源消耗，還會(huì)降低反應(yīng)器性能。傳統(tǒng)的生物量控制方法如高速水流沖洗、進(jìn)氣負(fù)荷控制、營養(yǎng)元素供給和化學(xué)清洗，雖有效但成本較高且可能影響反應(yīng)器恢復(fù)性能。本文的目的是探究pH值變化對(duì)脫硫生物反應(yīng)器微生物群落結(jié)構(gòu)的影響，分析不同pH范圍內(nèi)的反應(yīng)器性能和壓降變化，并提出利用pH控制生物量增長的策略，旨在提高脫硫性能并減少運(yùn)營成本，以推動(dòng)脫硫技術(shù)的發(fā)展和應(yīng)用。圖文摘要BTF系統(tǒng)對(duì)H2S的長期去除性能如圖1所示。在階段I，BTF系統(tǒng)在中性偏堿性條件下運(yùn)行（6.0<pH<9.5）。BTF在該階段獲得的對(duì)H2S的最大去除速率（ECmax）為246.5g/(m3·h)（去除率為82.8%）；階段II是弱酸性運(yùn)行階段（pH在2.6-5.5）。在該階段獲得的ECmax為142.8 g/(m3·h)（去除率為66.6%）。傳質(zhì)阻力的增加和硫氧化菌（SOB）的活性降低是造成弱酸性時(shí)期脫硫性能下降主要原因；階段III為極酸性運(yùn)行階段，在不添加堿性試劑的情況下，循環(huán)液的pH逐漸下降到1.0以下。BTF在該階段獲得的ECmax為164.6g/(m3·h)（去除率為65.0%）。極酸性時(shí)期的EC和SOB活性低于中性偏堿性時(shí)期，但明顯高于弱酸性時(shí)期。圖1 BTF在不同pH時(shí)期的長期運(yùn)行效

　　Hydrogen sulfide (H2S), a toxic and foul smelling gas with a foul egg odor, is present in many industrial activities. Biological treatment is considered the best method for treating this odorous gas, mainly due to its low cost and high safety. Among numerous bioreactors, the biological drip filter (BTF) has attracted much attention due to its controllable operating parameters and easy elimination of metabolites. However, bioreactors often encounter high pressure drop problems caused by excessive biomass accumulation during operation, which not only increases energy consumption but also reduces reactor performance. Traditional biomass control methods such as high-speed water flow flushing, intake load control, nutrient supply, and chemical cleaning are effective but costly and may affect reactor recovery performance. The purpose of this article is to explore the impact of pH changes on the microbial community structure of desulfurization bioreactors, analyze reactor performance and pressure drop changes within different pH ranges, and propose strategies for controlling biomass growth using pH, with the aim of improving desulfurization performance and reducing operating costs to promote the development and application of desulfurization technology. The long-term removal performance of the BTF system for H2S is shown in Figure 1. In Stage I, the BTF system operates under neutral to alkaline conditions (6.0<pH<9.5). The maximum removal rate (ECmax) of H2S obtained by BTF in this stage is 246.5g/(m3 · h) (removal rate of 82.8%); Stage II is the weakly acidic operating stage (pH between 2.6-5.5). The ECmax obtained at this stage is 142.8 g/(m3 · h) (removal rate of 66.6%). The increase in mass transfer resistance and the decrease in activity of sulfur oxidizing bacteria (SOBs) are the main reasons for the decline in desulfurization performance during weak acidic periods; Stage III is an extremely acidic operating stage, in which the pH of the circulating solution gradually decreases to below 1.0 without adding alkaline reagents. The ECmax obtained by BTF in this stage is 164.6 g/(m3 · h) (removal rate of 65.0%). The EC and SOB activities during the extremely acidic period are lower than those during the neutral alkaline period, but significantly higher than those during the weakly acidic period. Figure 1 Long term operation effect of BTF at different pH periods

　　圖2顯示了過濾床內(nèi)生物量和壓降（ΔP）的變化。生物量和ΔP在堿性運(yùn)行時(shí)期迅速增長。隨著pH降低至弱酸性范圍內(nèi)，在沒有進(jìn)行曝氣沖洗的前提下，生物量和ΔP開始呈現(xiàn)出降低的趨勢(shì)。當(dāng)循環(huán)液pH降低至1以下（極酸性時(shí)期），生物量和ΔP進(jìn)一步下降至10-11g/L和99-117Pa/m，并長期維持在該水平。圖2 過濾床內(nèi)生物量和ΔP變化圖3顯示了各時(shí)期生物膜菌群結(jié)構(gòu)變化。在中性偏堿性時(shí)期，BTF系統(tǒng)中富集到的微生物主要為耐堿和耐鹽的異養(yǎng)菌，如Pseudomonas、Stenotrophomonas、Brevundimonas、Halomonas、Brucella和Evansella。在弱酸性階段，這一時(shí)期的大多數(shù)細(xì)菌是輕度嗜酸的SOB，如Acidithiobacillus、Metallibacterium、Thiomonas和Acidiphilium等。一些異養(yǎng)細(xì)菌如Brucella和Evansella在這一時(shí)期未被檢測(cè)到，因?yàn)樗鼈冸y以適應(yīng)酸性的環(huán)境。在長期極酸性條件下，嗜酸性SOB-?Mycobacterium（79.2%）逐漸占據(jù)主導(dǎo)地位，非耐酸的微生物被淘汰。圖3 各時(shí)期生物膜菌群結(jié)構(gòu)變化

　　Figure 2 shows the changes in biomass and pressure drop (Δ P) within the filter bed. The biomass and Δ P increase rapidly during alkaline operation. As the pH decreases to the weakly acidic range, biomass and Δ P begin to show a decreasing trend without aeration flushing. When the pH of the circulating solution drops below 1 (during the extremely acidic period), biomass and Δ P further decrease to 10-11g/L and 99-117Pa/m, and remain at these levels for a long time. Figure 2 shows the changes in biomass and Δ P within the filter bed, while Figure 3 illustrates the structural changes in biofilm microbiota at different stages. During the neutral to alkaline period, the microorganisms enriched in the BTF system are mainly alkali and salt tolerant heterotrophic bacteria, such as Pseudomonas, Stenotrophomonas, Brevundimonas, Halomonas, Brucella, and Evansella. In the weakly acidic stage, most bacteria during this period are mildly acidophilic SOBs, such as Acinethiobacillus, Metallibacterium, Thiomonas, and Acidiphilium. Some heterotrophic bacteria such as Brucella and Evansella were not detected during this period because they had difficulty adapting to acidic environments. Under long-term extremely acidic conditions, acidophilic SOB Mycobacterium (79.2%) gradually dominates, and non acid resistant microorganisms are eliminated. Figure 3 Changes in the structure of biofilm microbiota in different periods

　　小結(jié)BTF在堿性、弱酸性和極酸性條件下獲得的ECmax分別為246.5、142.8和164.6 g/(m3·h)。中性偏堿下BTF的脫硫性能最佳，這是由于較低的H2S氣液傳質(zhì)阻力及較高的硫氧化菌活性。保持此pH范圍需消耗大量堿性試劑，這導(dǎo)致反應(yīng)器的運(yùn)行成本升高和操作過程變得復(fù)雜。在極酸環(huán)境中，耐酸的硫氧化菌-Mycobacterium逐漸占據(jù)主導(dǎo)（79.2%），且生物膜擁有高硫氧化活性，非耐酸的微生物被淘汰，這維持了系統(tǒng)內(nèi)生物量的穩(wěn)定（生物量濃度10-11g/L），避免了反應(yīng)器的堵塞，降低了生物量控制和pH調(diào)整的成本。通過富集高豐度且高活性嗜酸的Mycobacterium，BTF在極酸環(huán)境（pH < 1.0）下仍可獲得較高的脫硫性能，擴(kuò)大了生物反應(yīng)器運(yùn)行的pH范圍。

　　The ECmax values of BTF obtained under alkaline, weakly acidic, and extremely acidic conditions were 246.5, 142.8, and 164.6 g/(m3 · h), respectively. The desulfurization performance of BTF is optimal under neutral alkaline conditions, due to lower H2S gas-liquid mass transfer resistance and higher sulfur oxidizing bacterial activity. Maintaining this pH range requires a large amount of alkaline reagents, which increases the operating cost of the reactor and makes the operation process more complex. In extremely acidic environments, acid resistant sulfur oxidizing bacteria Mycobacteria gradually dominate (79.2%), and biofilms have high sulfur oxidation activity. Non acid resistant microorganisms are eliminated, which maintains the stability of biomass in the system (biomass concentration 10-11g/L), avoids reactor blockage, and reduces the cost of biomass control and pH adjustment. By enriching high abundance and high activity acidophilic Mycobacterium, BTF can still achieve high desulfurization performance in extremely acidic environments (pH<1.0), expanding the pH range of bioreactor operation.