Nitrogen and Phosphorus Limits for Nutrient Deficient Industrial Wastewaters

1991 ◽  
Vol 24 (3-4) ◽  
pp. 259-267 ◽  
Author(s):  
Christian H. Möbius
Keyword(s):  
Paper Industry ◽  
Treatment Plant ◽  
Pulp Mill ◽  
Operating Conditions ◽  
Inorganic N ◽  
Nitrogen And Phosphorus ◽  
Total N ◽  
Industrial Wastewaters ◽  
Treated Effluent ◽  
Plant Optimization

For biological treatment of nutrient deficient industrial wastewaters, such as those of the pulp and paper industry, the addition of nitrogen and phosphorus is essential. As a certain surplus is necessary, both elements will be found in the effluent in varying concentrations. For the often used activated sludge treatment 5 parts of N and 1 part of P are said to be required for elimination of 100 parts of BOD. In-plant optimization generally leads to about 3.5 parts of N and 0.6 parts of P for 100 parts of BOD. In most plants N is added as urea and P as phosphoric acid. Optimized nutrient dosage aimed at stable operating conditions in the treatment plant generally gives average concentrations of 1 mg/l of both ammonia N and phosphate P in the treated effluent. However, due to fluctuations in loading and efficiency, variation coefficients of more than 100 % result in maximum concentrations in 24 hours mixed samples of more than 10 mg/l for N and P. Three examples of operational results are evaluated and discussed in detail. Water quality requirements will impose general limitations on N and P concentrations in treated effluents. Depending on the concentration limits and on the type of limited substance - i.e. ammonia N, total inorganic N or total N, phosphate P or total P - different strategies have to be developed. Nutrient dosage depending on the wastewater amount will become state of the art in the near future. The next step would be a loading dependent dosage. No results of technical operation are known which show the effluent concentrations obtainable with this technique. For cases in which limits cannot be met with this strategy the possibilities of nitrification, denitrification and biological P removal are discussed for nutrient deficient wastewaters. Results show that nitrification will work at low ammonia concentrations, however no steady nitrification will be obtained. Denitrification, on the other hand, seems to be difficult with low nitrate concentrations. At the present stage, no technical process meeting stringent total N or total inorganic N limits is known to exist for this type of effluent. Low P concentrations in the effluent can only be achieved by tertiary treatment, preferably final flocculation filtration processes. However, these will give rise to special problems in the treatment of pulp mill wastewaters, which are discussed in the paper.

Nitrogen in the effluent of the pulp and paper industry

1997 ◽  
Vol 35 (2-3) ◽  
pp. 139-145 ◽  
Author(s):  
Risto Järvinen
Keyword(s):  
Inorganic Nitrogen ◽  
Paper Industry ◽  
Treatment Plant ◽  
Pulp Mill ◽  
Kraft Pulping ◽  
Bleached Kraft Pulp ◽  
Treated Effluent ◽  
Before And After ◽  
Nitrogen Concentrations ◽  
Biological Nitrogen

Nitrogen concentrations of effluent before and after treatment plant in two mills have been measured during five days time in a bleached kraft pulp mill and in a newsprint mill. In effluents before treatment the concentration of inorganic nitrogen was low but in the effluent of kraft pulping process, the main part is inorganic nitrogen. In effluent after treatment the concentration of inorganic nitrogen is low. After activated sludge treatment plant the concentration of dissolved organic nitrogen is about 0.6 mg/l and nitrogen in suspended solids determines fluctuation of nitrogen content in treated effluent. There is no need for biological nitrogen removal processes if the addition of nitrogen in the treatment is correct.

Wastewater services for small communities

2003 ◽  
Vol 47 (7-8) ◽  
pp. 65-71 ◽  
Author(s):  
S. Gray ◽  
N. Booker
Keyword(s):  
Lower Cost ◽  
Local Treatment ◽  
Treatment Plant ◽  
Septic Tank ◽  
Nitrogen And Phosphorus ◽  
Small Communities ◽  
Treated Effluent ◽  
Alternative Systems ◽  
Effective Removal ◽  
Regional Treatment

Connection to centralised regional sewage systems has been too expensive for small-dispersed communities, and these townships have traditionally been serviced by on-site septic tank systems. The conventional on-site system in Australia has consisted of an anaerobic holding tank followed by adsorption trenches. This technique relies heavily on the uptake of nutrients by plants for effective removal of nitrogen and phosphorus from the effluent, and is very seasonal in its efficiency. Hence, as these small communities have grown in size, the environmental effects of the septic tank discharges have become a problem. In locations throughout Australia, such as rural Victoria and along the Hawkesbury-Nepean River, septic tanks are being replaced with the transport of sewage to regional treatment plants. For some isolated communities, this can mean spending $20,000-$40,000/household, as opposed to more common connection prices of $7,000/household. This paper explores some alternative options that might be suitable for these small communities, and attempts to identify solutions that provide acceptable environmental outcomes at lower cost. The types of alternative systems that are assessed in the paper include local treatment systems, separate blackwater and greywater collection and treatment systems both with and without non-potable water recycling, a small township scale treatment plant compared to either existing septic tank systems or pumping to a remote regional treatment facility.The work demonstrated the benefits of a scenario analysis approach for the assessment of a range of alternative systems. It demonstrated that some of the alternatives systems can achieve better than 90% reductions in the discharge of nutrients to the environment at significantly lower cost than removing the wastewater to a remote regional treatment plant. These concepts allow wastewater to be retained within a community allowing for local reuse of treated effluent.

Evolution of the Southpest Wastewater Treatment Plant

2000 ◽  
Vol 41 (9) ◽  
pp. 7-14
Author(s):  
A. Jobbágy ◽  
B. Literáthy ◽  
F. Farkas ◽  
Gy. Garai ◽  
Gy. Kovács
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Phosphorus Removal ◽  
Treatment Plant ◽  
Low Flow ◽  
Nitrate Content ◽  
Nitrogen And Phosphorus ◽  
Treated Effluent ◽  
Processing Wastes

The treated effluent of the Southpest Wastewater Treatment Plant is discharged into a small, low-flow branch of the Danube susceptible to eutrophication. The first, high-load activated sludge system with a hydraulic retention time of 2.5 hrs in the aerated basins, was installed here in 1966. The paper presents the evolution of the technology by illustrating the effects of the different changes carried out since 1991. Reconfiguration of the existing activated sludge basins connected originally in parallel into an arrangement of tanks in series increased the settleability of the sludge as well as the efficiency of COD removal significantly. Introduction of an anaerobic zone preceding the aerated basins facilitated biological excess phosphorus removal with a consequent release in the thickener and digester. Introducing lime addition into the recycled sludge processing wastes significantly improved the performance of the system. However, since there had been no provision built for eliminating the nitrate content of the recycled sludge, efficiency of phosphorus removal proved to be dependent on the eventually occurring nitrification. In order to achieve both an effective nitrogen and phosphorus removal the current technology established in 1999 applies a nitrification and a denitrification filter following the activated sludge unit and uses precipitation for phosphorus removal.

Energy efficient aeration of wastewaters from the pulp and paper industry

2010 ◽  
Vol 62 (10) ◽  
pp. 2364-2371 ◽  
Author(s):  
M. Sandberg
Keyword(s):  
Oxygen Transfer ◽  
Biological Treatment ◽  
Bubble Column ◽  
Paper Industry ◽  
Electrical Power ◽  
Treatment Plant ◽  
Pulp Mill ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Paper Mills

More than 50% of the electrical power needed to treat pulp and paper industry effluents is used for aeration in biological treatment stages. A large share of the oxygen that passes through the wastewater is not consumed and will be found in the off-gas. Energy can be saved by aerating under conditions where the oxygen transfer is most efficient, for example at low concentrations of dissolved oxygen Consider the sludge as an energy source; electricity can be saved by avoiding sludge reduction through prolonged aeration. High oxygen transfer efficiency can be retained by using the oxygen consumption of biosolids. Quantified savings in the form of needed volumes of air while still achieving sufficient COD reduction are presented. The tests have been made in a bubble column with pulp mill process water and sludge from a biological treatment plant. These were supplemented with case studies at three pulp and paper mills.

scholarly journals Catchment modelling of sediment, nitrogen and phosphorus nutrient loads with SedNet/ANNEX in the Tully - Murray basin

2009 ◽  
Vol 60 (11) ◽  
pp. 1091 ◽  
Author(s):  
J. D. Armour ◽  
L. R. Hateley ◽  
G. L. Pitt
Keyword(s):  
Biophysical Model ◽  
Nutrient Loads ◽  
Inorganic N ◽  
Nitrogen And Phosphorus ◽  
Total N ◽  
Hill Slope ◽  
Eastern Australia ◽  
North Eastern ◽  
Wet Tropics ◽  
The Impact

A long-term, annual-average catchment biophysical model (SedNet/ANNEX) was used to calculate sediment, nitrogen (N) and phosphorus (P) loads in the Tully–Murray catchment of north-eastern Australia. A total of 119 000 t year–1 of suspended sediment, equivalent to 430 kg ha–1 year–1, was calculated to be exported to the Great Barrier Reef (GBR). Most of the sediment (64%) was generated from hill-slope erosion. The modelled load of dissolved inorganic N (1159 t year–1 or 4.2 kg N ha–1 year–1) was similar to that from other wet tropics catchments in Queensland with similar areas of sugarcane. Sugarcane produced 77% of this load. The annual loads of total N and total P were 2319 t and 244 t, respectively. Simulations (scenarios) were run to evaluate the impact of improved land management on pollutant loads to the GBR. A combination of improved cultivation and fertiliser management of sugarcane and bananas (99% of cropping land) and restoration of the most degraded riparian areas reduced sediment by 23 000 t year–1 (18%) and dissolved inorganic N by 286 t year–1 (25%). However, this reduction is much less than the reduction of 80% that may be needed in the catchment to meet target chlorophyll loads in the marine environment.

Full Scale Optimization of Biological Phosphorus Removal at Kelowna, Canada

1985 ◽  
Vol 17 (11-12) ◽  
pp. 243-257 ◽  
Author(s):  
W. K. Oldham
Keyword(s):  
Treatment Plant ◽  
Operating Conditions ◽  
Biological Nutrient Removal ◽  
Biological Phosphorus Removal ◽  
Nutrient Quality ◽  
Total N ◽  
Primary Sludge ◽  
Significant Difference ◽  
Anaerobic Zone ◽  
Scale Optimization

A newly constructed biological nutrient removal treatment plant operating in the Phoredox mode was used to test the effects on plant efficiency of varying two important operating conditions - the point of introduction of return sludge flow, and the addition of primary sludge thickener supernatant to the bioreactor. Overall treatment results for Kelowna's weak sewage showed that the effluent was consistently below 10 mg/L BOD and 4 mg/L suspended solids, while total P was below 2 mg/L 94 percent of the time, and total N was below 6 mg/L 90 percent of the time. There was no significant difference in effluent nutrient quality between tests with all return sludge entering the anaerobic zone or with half entering the anaerobic zone and half entering the first anoxic zone. Primary sludge thickener supernatant added to the anaerobic zone typically resulted in an effluent P concentration of less than 0.1 mg ortho-P/L, while the absence of supernatant produced an effluent containing greater than 2 mg ortho-P/L.

Recirculation of treated effluent in the bleaching of kraft pulp

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 8944-8964
Author(s):  
Erika Nascimben Santos ◽  
Claudia Mudadu Silva ◽  
Jorge Luiz Colodette ◽  
Samilly B. Zanith de Almeida ◽  
Antonio José Vinha Zanuncio ◽  
...  
Keyword(s):  
Kraft Pulp ◽  
Treatment Plant ◽  
Pulp Mill ◽  
Effluent Treatment ◽  
Organic Load ◽  
Kraft Pulp Mill ◽  
Treated Effluent ◽  
Effluent Treatment Plant ◽  
Attractive Option ◽  
Washing Water

The bleaching plant of a kraft pulp mill is the sector that consumes water and generates effluent with the highest volume. Water recycling is an attractive option to reduce water consumption and effluent generation. This study evaluated the technical feasibility of using treated effluent as washing water in the bleaching stages. The bleaching sequence was simulated in the laboratory using four types of washing water: deionized water, whitewater, low organic load effluent, and high organic load effluent. To achieve 90% ISO pulp brightness, the ClO2 consumption increased from 8.1 kg ClO2 odt-1 when using water to 13.8 and 16.3 kgClO2 odt-1 for the low and high organic effluents. Physical and optical tests of the hand-sheet papers did not show any statistical difference between various washing waters. The filtrates showed values that did not burden the efficiency of the effluent treatment plant. It was possible to use effluent in the bleaching stages, considering that the filtrates and the produced paper complied with the quality standards.

Implications of converting a kraft pulp mill to a dissolving pulp operation with a hemicellulose extraction stage

TAPPI Journal ◽  
2013 ◽  
Vol 12 (2) ◽  
pp. 29-38 ◽  
Author(s):  
ENRIQUE MATEOS-ESPEJEL ◽  
THEODORE RADIOTIS ◽  
NACEUR JEMAA
Keyword(s):  
Kraft Pulp ◽  
Paper Industry ◽  
Production Capacity ◽  
Pulp Mill ◽  
Dissolving Pulp ◽  
Operating Conditions ◽  
Pulp Mills ◽  
Kraft Pulp Mill ◽  
Efficiency Measures ◽  
Recovery Boiler

Global demand for dissolving pulp has been increasing at a remarkable pace over the last few years. A shortage in cotton and the expansion of the textile, hygiene, and health product markets are behind this booming demand. The Canadian pulp and paper industry has entered these markets by converting several paper-grade pulp mills to dissolving pulp producers. In the kraft process, part of the hemicellulose remains with the pulp after cooking and the rest is burnt in the recovery boiler to produce energy. In dissolving pulp mills, most of the hemicellulose must be removed from the wood chips in a pre-hydrolysis stage before pulping. Hemicellulose hydrolysis and its subsequent extraction will affect energy and chemical balances. In addition, the new operation will require large capital expenditures. The objective of this work was to study the conversion of a kraft pulp mill to a dissolving pulp operation and the extraction of hemicelluloses from the process. The effects of hemicellulose extraction on mill energy balance, equipment requirements, and new operating conditions were analyzed. Computer simulations of the process and thermal pinch analysis were used. The existing bottlenecks (digesters, lime kiln, and recovery boiler) to increasing the dissolving pulp production capacity were identified before and after the conversion. In addition, energy efficiency measures were identified to decrease the energy consumption of the new process.

Experimental Study on the Control of Nutrients in Activated Sludge Treatment

1994 ◽  
Vol 29 (5-6) ◽  
pp. 329-342 ◽  
Author(s):  
Reijo Saunamäki
Keyword(s):  
Waste Water ◽  
Activated Sludge ◽  
Phosphorus Content ◽  
Treatment Plant ◽  
Pulp Mill ◽  
Paper Mill ◽  
Waste Waters ◽  
Phosphorus Addition ◽  
Total N ◽  
Mill Waste

Laboratory experiments were conducted to determine the need for addition of phosphorus during the treatment of pulp and paper mill waste waters by the activated sludge method. The study also included the testing of different modifications of the activated sludge method (a completely mixed, three completely mixed reactors in series, anaerobic/aerobic) to see how different forms of phosphorus and nitrogen (total-N, NH+4 - N, NO-2 - N, NO-3 - N) are present in the influent and effluent. The tests were conducted using waste water from two newsprint/magazine paper mills and from a bleached sulphate pulp mill. Different loadings and levels of phosphorus addition were applied. When paper mill waste water was treated at normal loading (sludge load was c. 0.3 kgBOD/(kgMLVSS*d)), a small phosphorus addition was needed to secure efficient operation. The optimum BOD:P ratio was about 100:0.4, in which case the treated effluent had a total phosphorus content of c. 0.5 mg/l (about 70% reduction), a soluble phosphorus content of c. 0.3 mg/l and a phosphate phosphorus content of well below 0.1 mg/l. Larger phosphorus additions produced no further improvement in treatment results (BOD reduction c. 90% and COD c. 75%). Doubling the loading gave poorer results and the situation could not be rectified by adding phosphorus. Addition of phosphorus was not needed when treating pulp mill waste water, as has also been found when running activated sludge treatment plants at several mills. The BOD reduction (c. 95%) was excellent under all conditions. The COD reduction was 30-55%, AOX 30-35% and chlorophenols 90-95%. The total phosphorus content of the treated effluent was 0.3-0.7 mg/l when no phosphorus was added. This treatment also resulted in extremely low phosphate phosphorus levels. The biosludge contained 0.5-1.9% phosphorus, 0.5-0.8% when pulp mill waste waters were treated and occasionally around 2% for the paper mill. The experiments showed that it might be possible to operate the pulp mill treatment plant with even less phosphorus in relation to BOD compared with the BOD level of waste waters to which no phosphorus has been added. The mill could consider removing the excess phosphorus originating from lime mud neutralization before the waste water arrives at the treatment plant. In treating both these waste waters there is the risk of really high phosphorus discharges if care is not taken with the phosphorus addition. A typical situation of this type arises if the plant is run on the old "textbook rule" of BOD:P=100:1. The nitrogen was added as urea resulting in the BOD:N ratio of 100:(2.5-4.5). Total-N in the paper mill untreated waste water was in the range of 8.5-13 mg/l and in the effluent 2.5 - 5.0 mg/l, i.e. the removal was 55-75%. NH+4 - N in the influent was in the range of 1.5-3.0 mg/l and was totally removed in most of the runs. The concentration of (NO-2 - N + NO-3 - N) was only 40-50 µg/l, the removal was 0-85 % depending on the conditions. The activated sludge modification "three completely mixed reactors in series" yielded the best results when all parameters were taken into account.

Treatment of Wastewater in the Rhizosphere of Wetland Plants – The Root-Zone Method

1987 ◽  
Vol 19 (1-2) ◽  
pp. 107-118 ◽  
Author(s):  
Hans Brix
Keyword(s):  
Wastewater Treatment ◽  
Root Zone ◽  
Treatment Plant ◽  
Wetland Plants ◽  
Treated Wastewater ◽  
Treatment Standards ◽  
Nitrogen And Phosphorus ◽  
Zone Method ◽  
Total N ◽  
N Removal

The present paper describes the theoretical basis of wastewater treatment in the rhizosphere of wetland plants, the so-called “root-zone method”, along with the first working experiences from eight treatment plants in Denmark. Mechanically treated wastewater is led horizontally through the rhizosphere of wetland plants. During the passage of the wastewater through the rhizosphere, the wastewater is cleaned by microbiological degradation and by physical/chemical processes. The wetland plants supply oxygen to the heterotrophic microorganisms in the rhizosphere and stabilize the hydraulic conductivity of the soil. Nitrogen is removed by denitrification and phosphorus and heavy metals are bound in the soil. The first working experiences from Denmark show, that as far as BOD is concerned root-zone treatment plants are very nearly up to conventional secondary treatment standards already from the first growing season (removal efficiency: 51-95%). For the nutrients nitrogen and phosphorus the results vary (total-N removal: 10-88%; total-P removal: 11-94%). The removal efficiencies depended mainly on the composition of the soils and the degree of surface runoff in each treatment plant. It is concluded that root-zone treatment plants seem to be a viable alternative to conventional wastewater treatment technology, especially suitable for single households and small to medium sized communities. There is, however, still very little information on the removal processes for nitrogen (denitrification), on the effect of soil type and on the required surface area to load ratio,

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