UASB/EGSB反應器處理染整廢水之質傳及動力行為

本研究除了建立上流式厭氣污泥床(UASB)及膨脹顆粒污泥床(EGSB)反應器處理染整廢水之動力模式(incorporating intrinsic kinetics)及經驗模式(incorporating apparent kinetics)外，亦使用一組UASB反應器(表面流速1.0 m/h)及一組EGSB反應器(表面流速6.0 m/h)在有機負荷率0.5、1.0及2.0 kg COD/m3-d之操作條件下處理染整廢水(含PVA漿料回收廢水及染料廢水)以獲得實驗數據，另以批次之染整廢水厭氣降解實驗探intrinsic動力參數(打碎污泥顆粒)及apparent動力參數(原污泥顆粒)。據此，不僅可瞭解UASB反應器及EGSB反應器處理染整廢水之效能及污泥顆粒特性，亦可釐清基質降解動力及質傳效應，最後以實驗數據驗證動力模式與經驗模式之適用性。本研究於染整廠實際廢水外另添加葡萄糖基質以維持進流水COD濃度為1000 mg/L，UASB及EGSB反應器在有機負荷率0.5~2.0 kg COD/m3-d操作下，反應器內都形成良好的顆粒化污泥，整體COD去除率皆在76%~79%間；若不計所添加之葡萄糖，則原染整廢水COD去除率介於59%~64%間。此外，二種反應器之污泥顆粒粒徑(0.98~1.30 mm; 1.13~1.55 mm)及平均生物密度(104900~130070 mg VSS/L; 107470~134050 mg VSS/L)皆隨著有機負荷率之增加而增大，惟EGSB反應器之污泥顆粒粒徑及生物密度都略大於UASB反應器者。由批次實驗求得染整廢水厭氣降解之Monod intrinsic k值(1.0~1.1 mg COD/mg vss-d)略大於apparent k'值(0.7~0.9 mg COD/mg vss-d)，intrinsic Ks值(134~183 mg COD/L)則小於apparent K's (182~265 mg COD/L)且apparent K's值隨著有機負荷率之提高(污泥顆粒粒徑增大)而增大。動力模式求得UASB反應器之質傳參數(ϕ2 = 6.5~10.6、Bi = 3.0~4.3及η = 0.51~0.81)與EGSB反應器質傳參數(ϕ2 = 7.1~13.7、Bi = 7.8~10.2及η = 0.39~0.54)顯示，UASB及EGSB反應器之污泥顆粒質傳阻抗都以內部質傳阻抗為主要，且污泥顆粒之內部質傳阻抗對基質去除速率之影響相當大，內部質傳阻抗隨著有機負荷率之提高(污泥顆粒粒徑增大)而增加，EGSB反應器內污泥顆粒之質傳阻抗對整體基質去除速率之影響大於UASB反應器者。本研究建立之動力模式及經驗模式模擬之COD去除率與UASB及EGSB反應器處理染整廢水實驗値之誤差都在±8%範圍內，且動力模式與經驗模式模擬值之間差異百分比亦僅10%範圍內，顯示本研究建立之動力模式及經驗模式有其工程應用之價值。

關鍵字

上流式厭氣污泥床；膨脹顆粒污泥床；染整廢水；污泥顆粒特性；質傳；動力/經驗模式；模式驗證。

並列摘要

A kinetic model (incorporating intrinsic kinetics) and a homogeneous empirical model (incorporating apparent kinetics) that can be used for simulating variations in substrate residual concentration with different operating conditions in the upflow anaerobic sludge bed (UASB) reactor and expanded granular sludge bed (EGSB) reactor are formulated. One UASB reactor (us = 1.0 m/h) and one EGSB reactor (us = 6.0 m/h) were also used to treat textile wastewater by varying three different organic loading rates (OLRs = 0.5, 1.0 and 2.0 kg COD/m3-d) to generate experimental data. In addition, batch experiments were carried out to determine Monod intrinsic and apparent kinetic parameters by using disrupted and intact biomass granules. Thus, not only the performance and granule characteristics of UASB and EGSB reactors treating textile wastewater can be evaluated but the associated mass transfer and reaction kinetics can also be elucidated. In order to maintained a fixed influent COD concentration of 1000 mg/L, a designate amount of substrate glucose was supplemented to textile wastewater. When the UASB and EGSB reactors (reactor A and B) were maintained at the OLRs of 0.5–2.0 kg COD/m3-d, fairly good sludge granulation/settling can be achieved. Meanwhile, 76%–79% of the overall COD removal efficiencies or 59%–64% of the textile-contributed COD removal efficiencies can be reached. In addition, the average granule diameter (0.98–1.30 mm; 1.13–1.55 mm) and the average microbial density (107470–134050 mg VSSL; 104900–130070 mg VSSL) of the UASB and EGSB reactors increased with increasing OLR; the average microbial density and the average granule diameter of the former were moderately smaller than the latter. From the batch experiments, the obtained Monod kinetic parameter intrinsic k values (1.0–1.1 mg COD/mg VSS-d) are moderately larger than the apparent k' values (0.7–0.9 mg COD/mg VSS-d). The intrinsic Ks values (134–183 mg COD/L) are smaller than the apparent K's values (182–265 mg COD/L). A higher OLR (a larger biomass granule) gives a higher apparent K's value. By using the validated kinetic model, the calculated mass transfer parameter values (??2 = 6.5–10.6, Bi = 3.0–4.3, ?? = 0.51–0.81) reveal that the internal mass transfer resistance imposes a great effect on the overall substrate removal rate in the UASB and EGSB reactors; the effect of the internal mass transfer resistance on the overall substrate removal rate increases with increasing OLR. The calculated COD removal efficiencies using kinetic and empirical models are 8% deviated from the experimental results. The variations of the simulated results using kinetic and empirical models are within 10%.

並列關鍵字

upflow anaerobic sludge bed ； expanded granular sludge bed ； textile wastewater ； granule characteristics ； mass transfer ； kinetic/empirical model ； model validation

參考文獻

wastewater in a UASB reactor at moderate temperature : Performance

aspects. J. Ferment. Bioeng. 83: 179－184.

Alphenaar, P.A., Visser, A., Lettinga, G., 1993. The effect of liquid

Technol. 43: 249－258.

substrate transport limitation on porosity and methanogenic activity

國際替代計量

UASB/EGSB反應器處理染整廢水之質傳及動力行為

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