生物濾床被廣泛地運用在處理大型家禽和家畜畜牧場之廢氣，例如氨氣、甲烷、硫化物和揮發性有機物等。在處理過程中，奶粉或過期牛奶和磷酸會被添加入生物滴濾塔中，以提供生物膜的生長。然而，生物濾床的排放水中往往含有殘餘的養份，即磷酸及氨氮，在本研究中，我們研究回收水中的養份。從台南的一家養雞場取得的廢水中含有20,000毫克/公升的磷酸、8,000毫克/公升的銨及840毫克/公升的有機碳。我們選擇兩種金屬鹽（鎂鹽及鈣鹽）作為養份的沈澱劑。實驗的變數則專注在金屬鹽與磷酸的莫耳比例及溶液的酸鹼值。實驗系統的平衡計算是由電腦軟體（PHREEQC）所模擬，且模擬出的值亦和實驗結果做比較。實驗結果顯示，磷酸的去除率隨著金屬鹽劑量的增加而上升。若添加鎂鹽，最高的去除率達98％，沉澱物大多是磷酸三鎂（Mg3(PO4)2•8H2O, bobierrite）及少部分的磷酸銨鎂（MgNH4PO4•6H2O, struvite）；若添加鈣鹽，最高去除率則達到99%，沉澱物大多為氫氧基磷灰石（Ca5(PO4)3OH, hydroxyapatite）及一部分非結晶的磷酸鈣，而酸鹼值對於磷酸的去除亦是影響相當的大;磷酸的去除率大致隨著酸鹼值的增加而上升。對鎂鹽而言，磷酸的最高移除率約在酸鹼值是9的條件，因為當酸鹼值增加到10，鎂鹽的溶解度下降，而且氫氧化鎂的形成，均降低磷酸的去除率。對鈣鹽而言，磷酸的最高移除率約在酸鹼值是10的狀況。實驗結果顯示，當添加大量的鎂鹽及銨，有助於磷酸銨鎂的形成，其沉澱物經由x光繞射分析及濕式化學分析得知，大部分為磷酸銨鎂。本研究結果顯示，以化
學沉澱法回收生物濾床排放水中的養份是可行的。

The poultry or large livestock farms always produce odor in composting of fecal matters. Biofilters are usually used for controlling odorous gases, such as ammonia, methylamine, sulfide and volatile organic compound. Overdue milk and phosphate are usually added to the biofilter and provide the nutrient for biofilm growth. In the present study, recovery of nutrients was assessed from the blowdown of a biofilter from a large chicken farm in Tainan containing 20,000 mg/L of phosphate, 8,000 mg/L of ammonium and 835.8 mg/L of nitrate. Both calcium and magnesium salts were used as precipitants, respectively. Effects of pH and molar ratio of metal to phosphate were examined, and the experimental results were compared with modeling data as predicted by
PHREEQC.
Results revealed that maximum removal efficiencies of phosphate were 98% and 99% when using MgCl2 and CaCl2, respectively. The precipitates are mostly bobierrite (Mg3(PO4)2•8H2O) and hydroxyapatite (Ca5(PO4)3OH, HAP). Solution pH is also a significant parameter in the process. In general, removal efficiency of phosphate increases with increasing pH value. The favorable pH for magnesium and calcium salts are approximately at pH 9 and 10, respectively. Excess magnesium and ammonium concentrations seem to induce the formation of struvite (MAP) at pH 8.5.

Alvarez, R., Evans, L. A., Milham, P. J. and Wilson, M. A. (2004) Effects of humic material on the precipitation of calcium phosphate. Geoderma,
118(3-4), pp. 245-260.

Banu, R. J., Do, K. U. and Yeom, I. T. (2008) Phosphorus removal in low alkalinity secondary effluent using alum. Environmental Science and
Technology, 5(1), pp. 93-98.

Babic-Ivancic, V., Kontrec, J., Brecevic, L. and Krali, D. (2006) Kinetics of struvite to newberyite transformation in the precipitation system
MgCl2–NH4H2PO4–NaOH–H2O. Water Research, 40(18), pp. 3447-3455.

Cai, Z., Kim, D. and Sorial, G. A. (2007) A comparative study in treating two VOC mixtures in trickle bed air biofilters. Chemosphere, 68(6), pp.
1090-1097.

Cao, X. and Harris, W. G. (2008) Carbonate and magnesium interactive effect on calcium phosphate precipitation. Environmental Science and
Technology, 42(2), pp. 436-442.

Cao, X., Harris, W. G., Josan, M. S. and Nair, V. D. (2007) Inhibition of calcium phosphate precipitation under environmentally-relevant
conditions. Science of the Total Environment, 383(1-3), pp. 205-215.

Chen, Y. X., Yin, J. and Wang, K. X. (2005) Long-term operation of biofilters for biological removal of ammonia. Chemosphere, 58(8), pp.
1023-1030.

Chimenos, J. M., Ferna´ndez, A. I., Herna´ndez, A., Haurie, L., Espiell, F. and Ayora, C. (2006) Optimization of phosphate removal in anodizing
aluminum wastewater. Water Research, 40(1), pp. 137-143.

Chimenosa, J. M., Ferna´ndeza, A. I., Villalbaa, G., Segarraa, M., Urruticoecheab, A., Artazab, B. and Espiella, F. (2003) Removal of ammonium and phosphates from wastewater resulting from the process of cochineal extraction using MgO-containing by-product. Water Research,
37(7), pp. 1601-1607.

Chou, M. S. and Wang, C. H. (2007) Treatment of ammonia in air stream
by biotrickling filter. Aerosol and Air Quality Research, 7(1), pp. 17-32.

Dolye, J. D. and Parsons, S. A. (2002) Struvite formation, control and
recovery. Water Research, 36(16), pp. 3925-3940.

Freche, M. and Lacout, J. L. (1992) Effect of humic compounds and some organic acids added during dicalcium phosphate dihydrate crystal
growth process. Journal of Alloys and Compounds, 188(1-2), pp. 65-68.

Friend, A. L., Roberts, S. D., Schoenholtz, S. H., Mobley, J. A. and Gerard, P. D. (2006) Poultry litter application to loblolly pine forests:
growth and nutrient containment. Waste Management, 35(3), pp.
837-848.

Galarneau, E. and Gehr, R. (1996) Phosphorus removal from wastewaters: experimental and theoretical support for alternative mechanisms. Water
Research, 31(2), pp. 328-338.

Golubev, S. V., Pokrovsky, O. S. and Savenko, V. S. (1999) Unseeded precipitation of calcium and magnesium phosphates from modified
seawater solutions. Journal of Crystal Growth, 205(3), pp. 354-360.

Hao, X., Mark, C., Loosdrecht, M. C. M. V., Meijer, S. C. F. and Qian, Y. (2001) Model-based evaluation of two BNR processes - UCT and A2N.
Water Research, 35(12), pp. 2851-2860.

I˙rdemez, S., Yildiz, Y. S. and Tosunog˘lu, V. (2006) Optimization of phosphate removal from wastewater by electrocoagulation with aluminum plate electrodes. Separation and Purification Technology,
52(2), pp. 394-401.

Jeong, Y. K. and Kim, J. S. (2001) A new method for conservation of nitrogen in aerobic composting processes. Bioresource Technology, 79(2),
pp. 129-133.

Kalavrouziotis, I. K., Koukoulakis, P. H., Sakellariou-Makrantonaki, M. and Papanikolaou, C. (2009) Effects of treated municipal wastewater on the essential nutrients interactions in the plant of Brassica oleracea var.
Italica. Desalination, 242(1-3), pp. 297-312.

Kelleher, B. P., Leahy, J. J., Henihan, A. M., O’Dwyer, T. F., Sutton, D. and Leahy, M. J. (2002) Advances in poultry litter disposal technology - a
review. Bioresource Technology, 83(1), pp. 27-36.

Kim, D., Kim, K. Y., Ryu, H. D., Min, K. K. and Lee, S. (2009) Long term operation of pilot-scale biological nutrient removal process in treating municipal wastewater. Bioresource Technology, 100(13), pp.
3180-3184.

Kongshaug, K. O., Fjellvaﾟg, H. and Lillerud, K. P. (2001) The synthesis and crystal structure of a hydrated magnesium phosphate
Mg3(PO4)2•4H2O. Solid State Sciences, 3(3), pp. 353-360.

Kumar, M., Xie, J., Chittur, K. and Riley, C. (1999) Transformation of modified brushite to hydroxyapatite in aqueous solution: effects of
potassium substitution. Biomaterials, 20(15), pp. 1389-1399.

Le Corre, K. S., Valsami-Jones, E., Hobbs, P., Jefferson, B. and Parsons, S. A. (2007) Struvite crystallisation and recovery using a stainless steel
structure as a seed material. Water Research, 41(11), pp. 2449-2456.

Lu, S. G., Bai, S. Q., Zhu, L. and Shan, H. D. (2009) Removal mechanism of phosphate from aqueous solution by fly ash. Journal of
Hazardous Materials, 161(1), pp. 95–101.

Lind, B. B., Ban, Z. and Byde´n, S. (2000) Nutrient recovery from human urine by struvite crystallization with ammonia adsorption on zeolite and
wollastonite. Bioresource Technology, 73(2), pp. 169-174.

Ma, M. G., Zhu, Y. J. and Chang, J. (2006) Monetite formed in mixed solvents of water and ethylene glycol and its transformation to hydroxyapatite. Journal of Physical Chemistry, 110(29), pp.
14226-14230.

Marinho-Soriano, E., Nunes, S. O., Carneiro, M. A. A. and Pereira, D. C. (2009) Nutrients’ removal from aquaculture wastewater using the macroalgae Gracilaria birdiae. Biomass and Bioenergy, 33(2), pp.
327-331.

Mezenner, N. Y. and Bensmaili, A. (2009) Kinetics and thermodynamic study of phosphate adsorption on iron hydroxide-eggshell waste.
Chemical Engineering Journal, 147(2-3), pp. 87-96.

Nelson, N. O., Mikkelsen, R. L. and Hesterberg, D. L. (2003) Struvite precipitation in anaerobic swine lagoon liquid: effect of pH and Mg:P ratio and determination of rate constant. Bioresource Technology, 89(3),
pp. 229-236.

Og˘uz, E., Gürses, A. and Canpolat, N. (2003) Removal of phosphate from wastewaters. Cement and Concrete Research, 33(8), pp. 1109-1112.

Parent, G., Bélanger, G., Ziadi, N., Deland, J. P. and Laperrière, J. (2007) Precipitation of liquid swine manure phosphates using magnesium
smelting by-products. Waste Management, 36, pp(2). 557-567.

Plant, L. J. and House, W. A. (2002) Precipitation of calcite in the presence of inorganic phosphate. Colloids and Surfaces, 203(1-3), pp.
143-153.

Ramírez, M., Gómez, J. M., Aroca, G. and Cantero, D. (2009) Removal of ammonia by immobilized Nitrosomonas europaea in a biotrickling filter packed with polyurethane foam. Chemosphere, 74(10), pp.
1385-1390.

Rockne, K. J. and Brezonik, P. L. (2006) Nutrient removal in a cold-region wastewater stabilization pond: importance of ammonia volatilization. Journal of Environmental Engineering, 132(4), pp.
451-459.

Sakuma, T., Jinsiriwanit, S., Hattori, T. and Deshusses, M. A. (2008) Removal of ammonia from contaminated air in a biotrickling filter: Denitrifying bioreactor combination system. Water Research, 42(17), pp.
4507-4513.

Seida, Y. and Nakano, Y. (2002) Removal of phosphate by layered double hydroxides containing iron. Water Research, 36(5), pp.
1306-1312.

Shimamura, K., Tanaka, T., Miura, Y. and Ishikawa, H. (2003) Development of a high-efficiency phosphorus recovery method using a fluidized-bed crystallized phosphorus removal system. Water Science and
Technology, 48(1), pp. 163-170.

Song, Y., Hahn, H. H. and Hoffmann, E. (2002) Effects of solution conditions on the precipitation of phosphate for recovery a
thermodynamic evaluation. Chemosphere, 48(10), pp. 1029-1034.

Song, Y., Weidler, P. G., Berg, U., Nu¨esch, R. and Donnert, D. (2006) Calcite-seeded crystallization of calcium phosphate for phosphorus
recovery. Chemosphere, 63(2), pp. 236-243.

Song, Y., Yuan, P., Zheng, B., Peng, J., Yuan, F. and Gao, Y. (2007) Nutrients removal and recovery by crystallization of magnesium ammonium phosphate from synthetic swine wastewater. Chemosphere,
69(2), pp. 319-324.

Sugiyama, S., Yokoyama, M., Ishizuka, H., Sotowa, K. I., Tomida, T. and Shigemoto, N. (2005) Removal of aqueous ammonium with magnesium phosphates obtained from the ammonium-elimination of magnesium ammonium phosphate. Journal of Colloid and Interface Science, 292(1),
pp. 133-138.

Tseng, F. K. and Wu, K. L. (2004) The ammonia removal cycle for a submerged biofilter used in a recirculating eel culture system.
Aquacultural Engineering, 31(1-2), pp. 17-30.

Ubukata, Y. (2007) The role of particulate organic matter and acetic acid in the removal of phosphate in anaerobic/aerobic activated sludge
processes. Engineering in Life Sciences, 7(1), pp. 61-66.

Uludag-Demirer, S. U. and Othman, M. (2009) Removal of ammonium and phosphate from the supernatant of anaerobically digested waste activated sludge by chemical precipitation. Bioresource Technology,
100(13), pp. 3236-3244.

van der Stelt, B., Temminghoff, E. J. M., Van Vliet, P. C. J. and Van Riemsdijk, W. H. (2007) Volatilization of ammonia from manure as affected by manure additives, temperature and mixing. Bioresource
Technology, 98(18), pp. 3449-3455.

Warmadewanthi and Liu, J. C. (2009) Recovery of phosphate and ammonium as struvite from semiconductor wastewater. Separation of
Purification Technology, 64(3), pp. 368-373.

Yetilmezsoy, K. and Sapci-Zengin, Z. (2008) Recovery of ammonium nitrogen from the effluent of UASB treating poultry manure wastewater by MAP precipitation as a slow release fertilizer. Journal of Hazardous
Materials, 166(1), pp. 260-269.

You, S. J., Hsu, C. L., Chuang, S. H. and Ouyang, C. F. (2003) Nitrification efficiency and nitrifying bacteria abundance in combined
AS-RBC and A2O systems. Water Research, 37(10), pp. 2281-2290.

Zhang, G., Strom, J. S., Li, B., Rom, H. B., Morsing, S., Dahl, P. and Wang, C. (2005) Emission of ammonia and other contaminant gases from naturally ventilated dairy cattle buildings. Biosystems Engineering, 92(3),
pp. 355-364.

Zhang, Z., Rengel, Z. and Meney, K. (2007) Nutrient removal from simulated wastewater using Canna indica and Schoenoplectus validus in mono- and mixed-culture in wetland microcosms. Water, Air, and Soil
Polluiont, 183(1-4), pp. 95-105.