García de Lomas Juan, Corzo Alfonso, Gonzalez Juan M, Andrades Jose A, Iglesias Emilio, Montero María José
Dpto. Biología, Facultad de Ciencias del Mary Ambientales, Pol. Río San Pedro s/n, 11510-Pto. Real, Cádiz, Spain.
Biotechnol Bioeng. 2006 Mar 5;93(4):801-11. doi: 10.1002/bit.20768.
Biogenic production of sulfide in wastewater treatment plants involves odors, toxicity and corrosion problems. The production of sulfide is a consequence of bacterial activity, mainly sulfate-reducing bacteria (SRB). To prevent this production, the efficiency of nitrate addition to wastewater was tested at plant-scale by dosing concentrated calcium nitrate (Nutriox) in the works inlet. Nutriox dosing resulted in a sharp decrease of sulfide, both in the air and in the bulk water, reaching maximum decreases of 98.7% and 94.7%, respectively. Quantitative molecular microbiology techniques indicated that the involved mechanism is the development of the nitrate-reducing, sulfide-oxidizing bacterium Thiomicrospira denitrificans instead of the direct inhibition of the SRB community. Denitrification rate in primary sedimentation tanks was enhanced by nitrate, being this almost completely consumed. No significant increase of inorganic nitrogen was found in the discharged effluent, thus reducing potential environmental hazards to receiving waters. This study demonstrates the effectiveness of nitrate addition in controlling sulfide generation at plant-scale, provides the mechanism and supports the environmental adequacy of this strategy.
污水处理厂中硫化物的生物生成会引发气味、毒性和腐蚀问题。硫化物的产生是细菌活动的结果，主要是硫酸盐还原菌（SRB）。为防止这种产生，通过在工厂进水口投加浓缩硝酸钙（Nutriox），在工厂规模上测试了向废水中添加硝酸盐的效率。投加Nutriox导致空气中和水体中硫化物急剧减少，分别达到最大降幅98.7%和94.7%。定量分子微生物技术表明，相关机制是反硝化硫氧化细菌脱氮硫微螺菌的生长，而非直接抑制SRB群落。硝酸盐提高了初沉池中的反硝化速率，且硝酸盐几乎被完全消耗。在排放的废水中未发现无机氮显著增加，从而降低了对受纳水体的潜在环境危害。本研究证明了添加硝酸盐在工厂规模上控制硫化物生成的有效性，提供了作用机制，并支持了该策略的环境适宜性。
