Ammonia In Effluents Research Articles

An integrated, two-step biofiltration system with Ulva fasciata for sequenced removal of ammonia and nitrate in mariculture effluents

Secondary treatment of fishpond effluent is imperative for the removal of excess nitrate and phosphorus. Biofilters comprised of the green macroalgae, Ulva, exhibit several advantages for this process, including usability of the produced edible biomass. However, even low levels of ammonia in fishpond effluent inhibit the uptake of nitrate by Ulva. In order to overcome this drawback we examined Ulva faciata in a two-step biofiltration system. The biofiltration system comprised of two sequenced tanks where the upstream Ulva biofilter was fed directly with mariculture effluent containing both ammonia (as total ammonium nitrogen - TAN) and nitrate (as NO3-N) and the TAN-depleted but NO3-N-rich effluent from this biofilter were transferred to the downstream Ulva biofilter. The performance of each separate Ulva biofilter as well as that of the whole system was measured on a weekly regime over a culture period of three weeks. Between 81 and 95% of the dissolved inorganic nitrogen (TAN + NO3-N) in mariculture effluent was removed by the two-step biofilter, with specific removal of 89–100% of TAN and 57–78% of NO3-N in mariculture effluent by the upstream and downstream Ulva, respectively. Exposure of Ulva in upstream biofilters to higher N input with both TAN and NO3-N did not affect algal production rate, which was relatively similar to that in downstream biofilters fed with TAN-depleted, NO3-N-rich effluent, with mean specific growth rate of 17.85% d−1 (±3.1) in the different biofilters. Removal rates of TAN or NO3-N by upstream and downstream Ulva, respectively, were relatively similar, between 90 and 135 mmol N m−2 d−1, while PO4-P removal was much faster in downstream Ulva biofilters having only NO3-N as a N source. While TAN removal induced production of Ulva biomass with higher N, P and protein content, culture in NO3-N-rich effluent resulted in Ulva biomass with higher lipid content.

Culturable heterotrophic nitrification-aerobic denitrification bacterial consortia with cooperative interactions for removing ammonia and nitrite nitrogen in mariculture effluents

Nitrogen pollution from ammonia and nitrite has been a significant environmental concern in the aquaculture industry. Current studies mostly focus on the characteristics of heterotrophic nitrification and aerobic denitrification (HNAD) bacteria isolated from freshwater environments such as domestic wastewaters, whereas HNAD bacteria in mariculture have yet to be well understood. Herein, this study aimed to investigate the interactions between culturable HNAD bacteria from mariculture environments by combining high-throughput sequencing and traditional cell culture method, in order to develop potential microbial consortia for high-efficiency nitrogen removal in mariculture effluents. By twenty-five species of halophilic HNAD bacteria co-cultured in the synthetic mariculture effluent (ammonia: 20 mg/L, C/N: 5), ammonium removal was mainly driven by the cooperative interactions between strains from Marinomonas, Marinobacterium, Halomonas, and Cobetia. Due to the interspecific coexistence, three novel bacterial consortia of Marinomonas communis &Halomonas titanicae, Marinomonas aquimarina &Halomonas titanicae, and Marinomonas aquimarina &Cobetia marina exhibited significantly better ammonium removal efficiency and stability than single strains. Meanwhile, Marinomonas communis &Halomonas titanicae showed the highest nitrite removal rate of 0.76 mg NO2−-N/L/h. Importantly, these microbial consortia could convert more inorganic-N into bacterial biomass by assimilation and dissimilation instead of the increased nitrogen lost by denitrification. These findings will contribute to understanding and developing the culturable HNAD bacterial consortia for controlling inorganic-N pollution in mariculture effluents or other saline wastewaters.

Combinations of Ulva and periphyton as biofilters for both ammonia and nitrate in mariculture fishpond effluents

Periphyton-based biofilters for aquaculture effluent possess multiple advantages, in water oxygenation, CO2 reduction and production of useful biomass. The performance of a marine periphyton biofilter, in terms of uptake rate and efficiency in removing different forms of nitrogen, was investigated. A periphyton biofilter was paired with an upstream macroalgae biofilter stocked with Ulva to expose the periphyton to ammonia-depleted but nitrate-rich effluent. Three trials compared the removal of total ammonia-N (TAN), nitrate (NO3-N), total N and phosphorus. The biofiltration and growth performance of (1) the periphyton downstream to the Ulva tank, (2) periphyton alone and (3) Ulva alone were compared. Biofiltration performance was evaluated at different areal loads of TAN and NO3-N.Periphyton growth performance did not depend on the effluent nutrient composition or on N loads, and yielded between 7.3 and 10.6 g dry weight m−2 d−1. While the Ulva preferred uptake of TAN over NO3-N, the periphyton showed no preference between them, demonstrating flexible shifts between TAN and NO3-N uptake. TAN uptake rate by the periphyton was not influenced by the effluent composition. However, periphyton NO3-N uptake rate and efficiency rose about fivefold, up to 1.4 g NO3-N m−2 d−1 and 63%, respectively, upon depletion of TAN areal load below 0.18 g N m−2 d−1 (<0.3 mg L−1) by the Ulva pre-treatment. Normalizing nutrient uptake rate to biomass revealed similar uptake rate of TAN and phosphorus by periphyton and Ulva, while the periphyton took up nitrate much faster.By removing up to 76% of the total nitrogen, with specific removal efficiency of 97% of the TAN and of 67% of the NO3-N, the novel dual Ulva-periphyton biofilter revealed a synergistic potential in treatment of nutrient-rich mariculture effluents.

Photocatalytic abatement of ammonia in nitrogen-containing effluents

The photocatalytic abatement of aqueous ammonia, the major nitrogen-containing compound in livestock manure, was investigated employing (i) a batch reactor equipped with an immersion UVA lamp, containing aqueous suspensions of different commercial TiO2 powders and (ii) a 40L prototype plug flow photo-reactor, suitable for the photocatalytic treatment of real swine and bovine manure, consisting of 9 vertical elements connected in series, internally coated with a TiO2 film, each one centrally housing a UVA lamp. A preliminary systematic investigation performed with the first photo-reactor evidenced that ammonia conversion and the selectivity toward the main oxidation products (N2, NO2− and NO3−) depend on the amount of dissolved O2, on pH and on the photocatalyst's amount and structural features. Extremely promising results, in terms of both ammonia conversion (up to the 88%) and selectivity to nitrogen gaseous species (99%), were achieved when the prototype photo-reactor was fed with suitably pre-treated manure. The TiO2-based photocatalytic treatment can thus be considered an effective remediation technology for the abatement of nitrogen-containing pollutants in surface and groundwater, originating from large-scale animal husbandries.

Evaluation of anode materials for the electro-oxidation of ammonia and ammonium ions

The electrochemical treatment of effluents has been used as an alternative to conventional treatments because of advantages such as environmental compatibility, process versatility and high efficiency. In addition, electrochemical treatment methods have been demonstrated to be very useful in the treatment of poorly biodegradable effluents. Studies have demonstrated that the electrochemical treatment efficiency is directly related to the electrode material. These materials should have electro-activity for reactions with the targeted pollutants, have high activation energy for undesired reactions and be corrosion resistant. Platinum and DSA ® are known to be effective for the electro-oxidation of pollutants such as phenol, ammonia and ammonium ions. This work presents the results of a comparative evaluation of some materials that can be used as anodes for the electro-oxidation of ammonia and ammonium ions in petroleum refinery effluents. The selected materials were Pt, DSA ®, Ni, anodized Al and graphite. Cyclic voltammograms confirmed the electro-activity of the Pt and DSA ® electrodes and demonstrated the electro-activity of Ni. Anodic polarization revealed the electro-activity of graphite. Anodized Al electrodes showed no activity for the electro-oxidation of the analyzed compounds. The results for the Ni and graphite electrodes are promising.

Effects of ammonia in pulp mill effluents on estuarine phytoplankton assemblages: field descriptive and experimental results

A field descriptive and field/laboratory experimental program was carried out to evaluate the effects of ammonia (NH 3) discharged by a pulp mill on estuarine plankton. Field data indicated that ammonia concentrations in the receiving system (Amelia Estuary; range, 0.19–0.43 mg l −1) were significantly higher than those taken in the reference system (Nassau Estuary; range, 0.09–0.11 mg l −1). Significantly reduced chlorophyll a concentrations were noted in the Amelia system, and these varied inversely with ammonia concentrations. There were periodic reductions of light transmission in areas affected by mill effluents and in upper areas of both estuaries due to postulated urban storm water runoff. Field surveys indicated that whole water and net phytoplankton numbers and species richness were significantly lower in the Amelia system. Zooplankton numbers were significantly lower at various Amelia stations, whereas there were no significant differences in zooplankton species richness between the two study areas. The field results indicated that the most likely system-wide differences of water quality that could account for the noted biological responses were the relatively high ammonia concentrations in the Amelia system. Field ammonia levels in the Amelia system were significantly associated with observed impairment of key indices of phytoplankton assemblages in areas affected by mill discharges, especially during summer periods of maximal impact. Laboratory microcosm experiments with Skeletonema costatum indicated adverse effects of ammonia on chlorophyll indicators. Microcosm results indicated that ammonia had a stimulatory effect on S. costatum at mean concentrations of 0.06 mg l −1 with initial adverse effects of ammonia within a range of 0.1–0.24 mg l −1 and major effects at concentrations >0.46 mg l −1. Mesocosm experiments with ammonia indicated stimulatory effects from 0.11 to 0.14 mg l −1 with inhibition of phytoplankton growth at 0.20 mg l −1. The difference between stimulatory effects and inhibition of ammonia on S. costatum and phytoplankton assemblages was relatively small. Microcosm and mesocosm experiments with pulp mill effluents resulted in a broad range of responses to ambient ammonia concentrations indicating undetermined interactions of the effects of ammonia with other components of the effluents. Within the context of the noted ranges of impacts in both the field and the laboratory, it was suggested that long-term average ammonia concentrations in the Amelia River-estuary at the outfall station should not exceed 0.11 mg l −1 with short-term concentrations not exceeding 0.20 mg l −1. The pulp mill in the Amelia River-estuarine system has undertaken a restoration program based on these ammonia limits.

Recovery of Ammonia as Struvite from Anaerobic Digester Effluents

The effects of environmental conditions on ammonia removal as struvite (Magnesium ammonium phosphate, MAP) were studied in a laboratory scale batch reactor. MAP precipitation was carried out by adding phosphoric acid and magnesium source either as MgCl2 or MgO. The effect of temperature, pH, Mg:N:P ratios were studied. Temperature did not significantly affect ammonia removal between 25-40 °C and over 90% removal was obtained. The effect of pH, however, was significant and highest removal was reached at pH 8.5-9.0. The various stoichiometric ratios of ammonium to Mg and P have been tested and slight excess of Mg and P found to be beneficial for higher recovery of ammonia as struvite. However further increase in Mg and P ratios did not result in further ammonia removal which is also costly for the practical application of the process. When MgO was used as M source, the ammonia recovery was 60-70% whereas the use of MgCl2 has increased this figure up to 95%. In addition a two step purification process was developed to recover MAP crystals from impurities of the anaerobic digester. Firstly, precipitates were dissolved in acid and impurities were removed by centrifugation. The clarified supernatant was re-precipitated by adjusting its pH with caustic. It was shown that in the two steps process white MAP crystals could be obtained with over 85% recovery to be used for another applications. The economical analysis of the process has shown that ammonia in the digester effluents can be recovered at the cost of $7.5-8.0 kg−1 NH4 +-N. The rate of reaction is very fast and is completed almost in minutes. This simplifies the process design resulting in a smaller reaction vessel.

On-line flow injection monitoring of ammonia in industrial liquid effluents

A flow-injection method was applied to on-line analysis for ammonia in industrial liquid effluents. The method utilised the diffusion of gaseous ammonia from an alkaline sample stream, through a microporous membrane, into a bromothymol blue indicator stream, with the resulting colour change measured photometrically using a red LED. Following initial development work, the method was adapted to an automated, portable system, which was capable of linear response in the range 1–100 mg 1 −1 NH 3-N. The portable flow injection monitor was powered by an external 12 V battery, and performed two-point self-calibration during each analytical cycle. The monitor was capable of unattended, continuous on-line monitoring of effluent streams at two industrial sites over several days. The results obtained were in good agreement with those produced by an indophenol blue laboratory reference method.

Removal of Ammonium and Nitrate Ions from Mine Effluents by Membrane Technology

Abstract Ammonium and nitrate ions could be removed from synthetic and actual mine effluents by using nanofiltration (NF) and reverse osmosis (RO) membranes. RO membranes were found more effective in removing these ions (>99% for NH4 + and about 97% for NO3 −) than NF membranes (about 66% for NH4 + and about 43% for NO3 −). Removal of ammonia from synthetic solutions containing only ammonia and water by both NF and RO membranes was found to be very low (10–30%), indicating that ammonia in mining effluents existed not as free ammonia but as ammonium salt complexes. The degree of separation depends on the size of the ammonium salt molecule. Removal of ammonia in the form of ammonium iron sulfate from a synthetic solution by NF membranes reached more than 98% while the removal of ammonium sulfate compound from an actual effluent by the same membranes reached about 55%. Ammonia separation by membranes assures the production of quality water suitable for recycling in mining operations since the other metal ion...

Aufarbeitung Ammoniak enthaltender Abwässer – Verfahrens‐ und Kostenvergleich

AbstractPurification of waste water containing ammonia – Comparison of proces and costs. The present case study compares three processes for reduction of ammonia in liquid effluents with respect to process engineering and treatment costs: stripping with steam, stripping with air, and liquid membrane technology. The specific purification costs are estimated for plant capacities between 1 and 50 m3/h, for NH3 feed concentrations between 50 and 2000 ppm, and for waste water feed temperatures between 5 and 80ßC. Moreover, the NH3 exiting concentration is varied between 1 and 500 ppm. In the standard case, the estimates are based on a decrease to 5 or 50 ppm NH3 in the waste water. Two cases are considered: in one, it is assumed that the ammonium sulphate solution produced by all three processes must be evaporated down to a disposable form. Alternatively, it is assumed that the ammonium sulphate can be used without further work‐up.

The treatment of leachates from domestic wastes in landfills—I: Aerobic biological treatment of a medium-strength leachate

A medium-strength leachate from domestic solid wastes in a landfill (COD 5000 mg l −1, BOD 3000 mg l −1 was treated using aerobic biological processes in continuous-flow, laboratory-scale reactors at low temperatures. Each unit was completely mixed, and mixed liquor was wasted such that solids retention time (SRT) was equal to the hydraulic retention period. At 10 C with addition of phosphate (COD:P less than 100:1) SRT values of 10 days were required to obtained well-clarified effluents, and high removal of BOD (>;98%) and COD (>;92%). Reduction of temperature to 5°C resulted in adverse effects on settling of sludges from units with SRT values of less than 10 days, but in other units good removal of organic materials could still be obtained. These units operated successfully with concentrations of mixed liquor volatile suspended solids (MLVSS) of 1450 mg l −1, equivalent to a ratio of F/M of 0.21 kg BOD kg −1 MLVSS day −1 or less. Removal of ammoniacal nitrogen which took place (influent concentration 80 mg l −1 as N) resulted from incorporation in biomass, and at SRT values of 10 days no nitrification took place at 5 or 10 C. Higher concentrations of ammonia in influent leachates resulted in ammonia in effluents when the ratio of BOD:N was less than about 100:3.6. Increasing the SRT of units to 20 days resulted in erratic conversion to nitrite, but reduced pH-values and possible simultaneous denitrification caused floating sludges and poorly-clarified effluents. Removal of ammonia is identified as a major problem when treating leachates, and further research is recommended.

A reevaluation of the toxicity of coal conversion process waters.

The acute toxicity to Daphnia magna of both untreated and treated process waters from a hydrocarbonization (HCZ) coal conversion process was evaluated recently by PARKHURST et al. (1979). Phenol, ammonia, and the three cresol isomers displayed additive toxicity in the untreated HCZ effluent. However, the treated HCZ effluent, in which concentrations of ammonia, phenol, and the cresols were reduced by biological oxidation, was much less toxic than might have been predicted from the concentrations of the individual components. At the LC50 dilution for the treated HCZ effluent, the concentration of total ammonia present was more than three times the LC50 value for D. maqna. This indicated a less-than-additive ammonia toxicity ~dT-6~--antagonistic interactions among ammonia and the other constituents. The less-than-additive ammonia toxicity was calculated from total ammonia concentrations and was attributed by PARKHURST et al. to a lower pH in the treated HCZ effluent than in a separate ammonia toxicity bioassay. But total ammonia includes both un-ionized ammonia (NH3) and ionized ammonia (NH4 +) in a pH- and temperature-dependent equilibrium. Un-ionized NH 3 is toxic to many aquatic organisms while NH4 + is relatively nontoxic (MCKEE and WOLF 1963). Therefore, if D__ L. magna are indeed more sensitive to NH 3 than to NH4 +, PARKHURST et al. incorrectly calculated the contribution of ammonia to the HCZ effluent toxicities by using total ammonia rather than un-ionized ammonia concentrations. Their interpretations of the importance of ammonia in these HCZ effluents may, therefore, be misleading and are reevaluated in the present report. The purposes of this paper are (1) to clarify the role of ammonia in the toxicity of complex coal conversion wastewaters, (2) to reevaluate the toxic contribution of ammonia in the treated HCZ effluent, and (3) to compare these results with literature reports for other coal conversion effluents (DEGRAEVE et al. 1980, HERBERT 1962). For the U.S. Department of Energy's Hanna-3 underground coal gasification (UCG) condenser water, DEGRAEVE et al. evaluated the interaction of phenol and ammonia in the toxicity of this process water to aquatic biota. Similarly, HERBERT determined the toxic contributions of phenol and ammonia in spent coal distillation process liquors to rainbow trout.