Rationale and Implementation of a Strategy to Restore Urban Lakes in Berlin: Results after Ten Years of Phosphorus Removal

1992 ◽  
Vol 27 (2) ◽  
pp. 239-256 ◽  
Author(s):  
Günter Klein

Abstract All lakes in the Berlin area have received excessive phosphorus loads during the last century. Restoration measures during the 1980s reduced the phosphorus input to three of these lakes considerably (from about 0.5-2 mg/L down to 0.005-0.02 mg/L total P). Although the chief measure—phosphate precipitation (flocculation, sedimentation and filtration)—reduced input to the greatest extent exercised so far worldwide, it became evident that such lakes may nevertheless need 4-6 years to show significant signs of recovery. Although the nutrient budget reacted rapidly, biocoenotic reactions differed between the lake types. The Berlin experience shows that urban lake areas cannot be restored by conventional sewage treatment and restoration techniques, but will need a great variety of additional techniques in order to show success. P- removal from the main inflow down to a few µg/L of total P is a minimum requirement. However, further well suited techniques have to be developed for the specific situation in each of the Berlin lakes in order to achieve nutrient removal to the extent which is in accordance with the present knowledge of eutrophication processes as well as with the special situation of each case. This refers to dosage of chemicals, removal of algae from treated surface water, filtration techniques, and hypolimnetic drainage. The costs of lake restoration in Berlin amount to less than 0.30 DM per m3 of treated water—a price which has demonstrated good results in the last few years. These results are of greatest importance for the further planning of water resources management, recreation, and for a safe drinking water supply for the growing urban area of reunified Berlin with its 4 million inhabitants.

1985 ◽  
Vol 17 (11-12) ◽  
pp. 213-232 ◽  
Author(s):  
A. G. Best ◽  
C. J. Hatton ◽  
A. J. Rachwal ◽  
B. Hurley

A three year project to improve the performance of a conventional diffused air activated sludge plant was carried out on a 4000 m3/day stream at the Basingstoke Sewage Treatment Works of Thames Water Authority from 1981-1984. The modified plant named ROTANOX comprised the use of rotary flow through two adjacent aeration lanes with the introduction of an anoxic section for denitrification. In the last 12 months of the study an anaerobic zone was created at the front of the plant and, after establishment of the necessary operating conditions, biological phosphorus removal was monitored. An effluent with a mean of 4 mg/l BOD, 11 mg/l SS and 2 mg/l NH3-N was achieved during the first two years of operation and energy consumption was reduced by 15%. In the final year a mean total P removal of 5.7 mg/l was recorded with the highest monthly average being 10 mg/l removal. This was equivalent to mean percentage removal of 40% and 47% respectively.


Author(s):  
Valerijus GASIŪNAS

Meat processing wastewater is heavily contaminated with phosphorus. It can be removed from wastewater by the use of flocculants. Phosphorus removal efficiency was estimated by treating wastewater with ferric sulphate flocculant, containing 11.5 percent of the active ingredient Fe3+ by weight. The research was conducted with wastewater pretreated in an aeration tank. Wastewater, containing 41.0 ± 3.5 mg l-1 of total phosphorus (TP), was dispensed into calibrated 1.0 liter containers with the following concentrations of flocculating agent: 0, 30, 75, 120, 150, 300, 450, 600, 750, 900 and 1,050 mg/l. The study showed that TP removal efficiency depends on the flocculant dose used for treatment. Increasing the flocculant dose decreases the efficiency of TP removal. One gram of Fe3+, given the flocculant dose of 40 gFe3+/m3, removed 0.5 g/m3 of TP, while 120 g/m3 of the flocculant removed around 40 percent less. According to the dependence of total P removed on the flocculant dose calculated by its active ingredient Fe3+, ferric sulphate flocculant is the most effective at doses of up to 60–80 g/m3 of Fe3+. The use of ferric sulphate may be limited by its impact on pH and sulphate concentrations in the effluent wastewater. If pH is not additionally adjusted, a maximum concentration of 70 g Fe3+/m3 can be used in order to maintain the pH of wastewater above 6.5 and to keep final sulphate concentration below 300 mg/l. In summary, a maximum of 70 g Fe3+/m3 can be used based on the total P removal efficiency and limiting factors. Such dose could remove 28 g total P/m3 from the wastewater. Since the permissible total P concentration in effluent wastewater is 4.0 mg/l, it is reasonable to use the ferric sulphate flocculant, containing 11.5 % of Fe3+ as an active ingredient, for treating wastewater with an initial total P concentration of up to 32 mg/l.


2006 ◽  
Vol 53 (12) ◽  
pp. 169-175 ◽  
Author(s):  
K. Wood ◽  
G. Wood ◽  
D. Prokop ◽  
F. Lewyille

A soy protein manufacturing facility was faced with the challenge of reducing its effluent phosphorus (P) content from 20–50 mg L−1 down to <2 mg L−1 total P without increasing soluble salt levels to comply with discharge and receiving water requirements. A number of biological and chemical P removal technologies previously evaluated either failed to achieve the new standards or would have produced prohibitive amounts of residual sludge and unacceptably high effluent salt concentrations. Lime precipitation, utilising a novel crystallisation technology, was demonstrated through on-site pilot testing to meet the process objectives. It is capable of achieving the required P removal at pH 10 while not increasing soluble salts and producing rapid settling and filterable particles. Also, minimal carbonate removal was observed with residual solids generation being only 40% of a complete lime softening reaction. This paper describes the technical evaluation that led to the full-scale treatment system that was put into operation in late 2005.


1997 ◽  
Vol 32 (4) ◽  
pp. 733-750
Author(s):  
R. Mark Palmer

Abstract Sewage treatment studies at the watershed scale, compared to case-by-case community projects, ensures the most cost-efficient investment of funds commensurate with environmental requirements to sustain growth. A three-year environmental assessment study for the town of New Tecumseth, Ontario, examined all nutrient inputs to the Nottawasaga River watershed. Other challenging watershed constraints were investigated, such as stream and river flow takings for irrigation and sediment transport, prior to the selection of the master sewage treatment plan. The findings from the field research and computer modelling were used to (1) place a realistic perspective on nutrient impacts, present and future, attributable to treated sewage effluent; (2) design a master plan that could be used as an opportunity in terms of reusing the effluent locally for agricultural irrigation; (3) provide a real-time assurance of the plan’s performance/compliance, based on the actual carrying capacity of the aquatic ecosystem; (4) stage the construction of the plan in a cost-effective and environmentally sound manner; and (5) recommend a water resources management strategy to control other nutrient and sediment load sources within the watershed. The recommended master sewage treatment plan and water resources management strategy can restore the Ministry of Environment and Energy provincial water quality objective concentration for total phosphorus within the river during 7Q20 flow conditions.


1985 ◽  
Vol 17 (11-12) ◽  
pp. 297-298 ◽  
Author(s):  
Takao Murakami ◽  
Atsushi Miyairi ◽  
Kazuhiro Tanaka

In Japan various biological phosphorus removal processes have recently been researched by laboratory or pilot plant scale studies and most of them have shown good results. Based on these results, the Japan Sewage Works Agency has conducted a full scale study of the biological phosphorus removal process from June 1982 until February 1983, which was the first full scale operation of this process in Japan. The main purpose of the study was to evaluate phosphorus removal efficiency and also nitrogen removal efficiency of the process and in addition, to ascertain the important operating factors of the process. For the study a treatment train of a large scale sewage treatment plant was remodelled. The aeration tank of 3.825 m3 volume was divided into four equal cells. The whole train including return sludge line was operated entirely independently of the other trains. During the experiment the train was operated under two different modes, Mode 1 and Mode 2. In Mode 1, the train was operated as an A/O process, the first cell of the aeration tank being anaerobic and the other cells oxic. In Mode 2, the train was operated as a Modified Phoredox process. In this case, the first cell was anaerobic, but the second cell was anoxic and nitrified liquor was returned to it from the end of the oxic cells. Mode 1 and Mode 2 were further divided into many ‘runs' and the flow rate varied between 12,550 m3 d−1 and 25,270 m3 d−1 , corresponding to retention times of 7.3 hours and 3.6 hours, respectively. Throughout the experimental period the mean value of influent (primary effluent) total-P concentration was 3.38 mg 1−1 , and that of the final effluent was 0.47 mg 1−1 . A cumulated frequency curve of the data showed that about 93% of measured effluent total-P was below 1.0 mg l−1 . Therefore, it can be concluded that with these influent total-P levels, biological phosphorus removal processes can sufficiently satisfy the effluent standard of 1 mg 1−1 total-P. Even when the process was operated as a Modified Phoredox Process, no obstruction to phosphorus removal because of nitrification was observed and phosphorus removal remained good. However, since the sewage treatment plant treated influent from a combined sewerage system, phosphorus removal was sometimes affected by heavy rainfalls. In such cases phosphorus release in the anaerobic cell was insufficient because of increased influent NOx concentration and accordingly increased denitrification level in the anaerobic cell. Therefore, as a result, enhanced phosphorus uptake in the following cells could not be observed. Higher process stability can be expected if an effective countermeasure to high influent NOx concentration can be made. Influence of flow rate fluctuation on the process was also studied. The treatment train was operated for a week under a daily flow rate fluctuation pattern which ranged between 460 m3 hr−1 and 820 m3 hr−1 . Nevertheless, the effluent total-P concentration showed no increase and stayed constantly lower than 0.5 mg 1−1. The oxidation reduction potential (ORP) was an effective control index to evaluate the degree of phosphorus release in the anaerobic cell. Water temperature did not affect phosphorus release and uptake rates.


1991 ◽  
Vol 24 (7) ◽  
pp. 133-148 ◽  
Author(s):  
A. Peter ◽  
F. Sarfert

In investigations concerning sludge bulking in Berlin enhanced biological phosphorus removal was first observed unexpectedly. Because since 1986 an officially preset limit of 2 mg TP/l must be kept in all Berlin wastewater discharges it was decided to explore the capabilities of the observed mechanism under the specific circumstances of the exciting two large treatment plants in Ruhleben (240,000 m3/d) and Marienfelde (100,000 m3/d). For this purpose some of the existing units at both plants were equipped with anaerobic zones which were generated mainly by process modifications. Additionally stage one of the Ruhleben plant was altered completely in order to investigate the combination of biological phosphorus and nitrogen removal as a special pilot study in three parallel trains. The research activities and treatment results gained in each of the two stages of the Ruhleben and in the Marienfelde plant are reported in detail. For example BOD-related phosphorus removal rates were obtained ranging from 2.3-4.5 mg TP per 100 mg BOD removed. It must be stressed that all examinations were performed on full-scale conditions. At present the given limit of 2 mg TP/l in the Ruhleben plant is met without any chemical precipitation at least on average. From the beginning biological phosphorus removal will be integrated into further projected extensions.


1994 ◽  
Vol 29 (7) ◽  
pp. 153-156 ◽  
Author(s):  
D. Wedi ◽  
P. A. Wilderer

Most of the fundamental processes responsible for enhanced biological phosphorus removal (EBPR) were obtained through laboratory tests under defined conditions with pure or enriched cultures. Acinetobacter sp. was identified as the most important group of bacteria responsible for bio-P removal. Full scale data showed, however, that laboratory results do not match full scale results well enough. There is a lack of data on the effects of sub-optimal process conditions such as inadequate availability of volatile fatty acids (VFA), high nitrate recycle, storm water inflow or low temperatures. In this paper the results of full scale experiments on P-release are presented and compared with theoretical values. Measurements at a full scale Phoredox-system showed a surprisingly low P-release in the anaerobic reactor. Only 4 to 10% of the phosphorus in the activated sludge was released in the bulk liquid. With laboratory batch-tests, a maximum of 20% of the P in the sludge could be released. It is assumed that under the prevailing process conditions either the fraction of Acinetobacter sp. was very small, or bacteria other than Acinetobacter sp. were responsible for the P-removal, or most of the phosphorus was bound chemically but mediated by biological processes.


1998 ◽  
Vol 37 (3) ◽  
pp. 241-247 ◽  
Author(s):  
Peter Gerdes ◽  
Sabine Kunst

The bioavailability of phosphorus from different sources has been evaluated in the catchment area of the River Ilmenau (Lower-Saxony, Germany) by using algal assays. The P bioavailability describes the different potential of P from various sources of supporting eutrophication. Effluents from sewage treatment plants were highly bioavailable (72% of TP) whereas rainwater (26%) and erosion effluents (30%) showed a low bioavailability. In order to develop effective strategies to minimize P inputs into the river, source specific P bioavailability indices were determined and combined with a P balance to calculate inputs of vioavailable P (BAP) instead of total P (TP). It could be shown that the relative importance of the different P sources changes when applying BAP. Measures to reduce P inputs into the River Ilmenau will take P bioavailability into consideration and therefore lead to a more cost-effective management.


2000 ◽  
Vol 41 (4-5) ◽  
pp. 503-508 ◽  
Author(s):  
R.F. Gonçalves ◽  
F. Rogalla

This work describes laboratory scale research about Enhanced Biological Phosphorus Removal (EBPR) in a submerged biofilter under Anaerobic/Oxic (A/O) alternation and continuous feed. Its main purpose is to detail the behaviour of the reactor throughout the anaerobic and the aerobic phases of the A/O cycle, to study the importance of the anaerobic phase in the selection of the EBPR bacteria in the biofilm and to evaluate the consumption and the importance of the organic substrate during the anaerobic phase. The mass balance over the Phosphorus (P) element indicates that long anaerobic phases (6 h) are more efficient than short ones (3 h) as a selector of EBPR bacteria in biofilms. In both comparisons, thespecific mass of P released in a 6 h period represents almost 50% more than the amount of P release in the shorter period (3 h). However, the presence of rapidly biodegradable COD in the influent of the anaerobic phase is a more effective selector, more important than the duration of the anaerobic phase: by doubling the amount of acetic acid in the influent, a similar 50% increase of P-release can be achieved at short anaerobic periods of 3 h. The effect of the strategy adopted in this study, focusing on selecting EBPR bacteria in biofilm, is shown by the P levels of 4% (total P/SST) in the sludge removed from the BF by backwashing in all periods.


2003 ◽  
Vol 48 (1) ◽  
pp. 87-94 ◽  
Author(s):  
B. Lesjean ◽  
R. Gnirss ◽  
C. Adam ◽  
M. Kraume ◽  
F. Luck

The enhanced biological phosphorus removal (EBPR) process was adapted to membrane bioreactor (MBR) technology. One bench-scale plant (BSP, 200-250 L) and two pilot plants (PPs, 1,000-3,000 L each) were operated under several configurations, including pre-denitrification and post-denitrification without addition of carbon source, and two solid retention times (SRT) of 15 and 26 d. The trials showed that efficient Bio-P removal can be achieved with MBR systems, in both pre- and post-denitrification configurations. EBPR dynamics could be clearly demonstrated through batch-tests, on-line measurements, profile analyses, P-spiking trials, and mass balances. High P-removal performances were achieved even with high SRT of 26 d, as around 9 mgP/L could be reliably removed. After stabilisation, the sludge exhibited phosphorus contents of around 2.4%TS. When spiked with phosphorus (no P-limitation), P-content could increase up to 6%TS. The sludge is therefore well suited to agricultural reuse with important fertilising values. Theoretical calculations showed that increased sludge age should result in a greater P-content. This could not be clearly demonstrated by the trials. This effect should be all the more significant as the influent is low in suspended solids.


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