Nitrification-denitrification in waste stabilisation ponds: a mechanism for permanent nitrogen removal in maturation ponds.
نویسندگان
چکیده
A pilot-scale primary maturation pond was spiked with (15)N-labelled ammonia ((15)NH(4)Cl) and (15)N-labelled nitrite (Na(15)NO(2)), in order to improve current understanding of the dynamics of inorganic nitrogen transformations and removal in WSP systems. Stable isotope analysis of delta(15)N showed that nitrification could be considered as an intermediate step in WSP, which is masked by simultaneous denitrification, under conditions of low algal activity. Molecular microbiology analysis showed that denitrification can be considered a feasible mechanism for permanent nitrogen removal in WSP, which may be supported either by ammonia-oxidising bacteria (AOB) or by methanotrophs, in addition to nitrite-oxidising bacteria (NOB). However, the relative supremacy of the denitrification process over other nitrogen removal mechanisms (e.g., biological uptake) depends upon phytoplanktonic activity.
منابع مشابه
Nitrogen transformations and balance in channel catfish ponds
A nitrogen (N) budget was developed for four, 400-m ponds stocked with 550 channel catfish (Ictalurus punctatus) fingerlings that were fed to satiation daily for 133 days with a ration containing 4.85% N. Feed accounted for 87.9% of the N input to ponds. Abundant N from ammonia (NH3), ammonium (NH4 ), and nitrate (NO3 ) and the high total N: total phosphorus ratio in pond waters prevented appre...
متن کاملAmmonia volatilisation in waste stabilisation ponds: a cascade of misinterpretations?
Ammonia volatilisation has generally been reported as, or assumed to be, the main nitrogen removal mechanism in waste stabilisation ponds (WSP). Nitrogen removal via ammonia volatilisation is based on two observations: (a) in-pond pH values can reach high values (>9, even >10), so increasing the proportion of the total ammonia present as the un-ionized form or free ammonia (NH(3)); and (b) in-p...
متن کاملDenitrification and Anammox in Tropical Aquaculture Settlement Ponds: An Isotope Tracer Approach for Evaluating N2 Production
Settlement ponds are used to treat aquaculture discharge water by removing nutrients through physical (settling) and biological (microbial transformation) processes. Nutrient removal through settling has been quantified, however, the occurrence of, and potential for microbial nitrogen (N) removal is largely unknown in these systems. Therefore, isotope tracer techniques were used to measure pote...
متن کاملNutrient Removal by Algae Grown in CO2-Enriched Wastewater over a Range of Nitrogen-to-Phosphorus Ratios
In conventional wastewater treatment, biological nutrient removal (BNR) depends on bacterial assimilation for phosphorus removal and nitrification+denitrification for nitrogen removal, with the resulting loss of the fixed nitrogen resource. Alternatively, treatment by microalgae allows for assimilative removal of both phosphorus (P) and nitrogen (N) thereby avoiding the oxygen demand of nitrifi...
متن کاملBaffle and fixed media effects on coliform removal and bacterial die-off rate coefficient in waste stabilization ponds (a case study in Ahvaz)
Background: The use of waste stabilization ponds is one of the cheapest wastewater treatment processes. This study evaluated the effects of baffles and fixed media on coliform removal in facultative lagoons. Methods: In this study, the settled wastewater from four pond systems of the city of Ahvaz was used as input. Each system was composed of two ponds that were connected to each other serial...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Water science and technology : a journal of the International Association on Water Pollution Research
دوره 61 5 شماره
صفحات -
تاریخ انتشار 2010