BOD Loading Research Articles

밀양강 중권역 오염부하 전망 및 삭감 시나리오별 하류 수질예측

Milyanggang mid-watershed is located in downstream of Nakdong river basin. The pollutants from that watershed have an direct effect on Nakdong river water quality and it's control is important to manage a water quality of Nakdong river. A target year of Milyanggang mid-watershed water environment management plan is 2013. To predict a water quality at downstream of Milyang river, we have investigated and forecasted the pollutant source and it's loading. There are some plan to construction the sewage treatment plants to improve the water quality of Milyang river. Those are considered on predicting water quality. As results, it is shown that the population of Milyanggang mid-watershed is 131,857 and sewerage supply rate is 62.2% and the livestock is 1,775.300 in 2006. It is estimated that the population is 123,921, the sewerage supply rate is 75.5% in 2013. The generated loading of BOD and TP is 40,735 kg/day and 2,872 kg/day in 2006 and discharged loading is 11,818 kg/day and 722 kg/day in 2006 respectively. Discharged loadings were forecasted upward 1.0% of BOD and downward 2.7% of TP by 2013. The results of water quality prediction of Milyanggang 3 site were 1.6 mg/L of BOD and 0.120 mg/L of TP in 2013. It is over the target water quality at that site in 2015 about 6.7% and 20.0% respectively. Consequently, there need another counterplan to reduce the pollutants in that mid-watershed by 2015.

A design model for nitrification on structured cross flow plastic media trickling filters

AbstractAn empirical model has been developed to predict the effluent ammoniacal nitrogen concentration from structured cross flow plastic media trickling filters operated over the range of BOD loadings 0.12–0.38 kg/m3/day and ammoniacal nitrogen loadings of 0.06–0.23 kg/m3/day. The model gives good predictions based on 24‐h average effluent concentrations over a range of filter depths, organic and hydraulic loading rates. When incorporated with suitable hydraulic models, effluent ammoniacal concentration can be predicted through the diurnal range. The data gathering for the model included depth profiles on three filters. These have shown that at all but the very highest BOD loadings, nitrification commences from the very top of the filter in the presence of soluble BOD loadings previously thought to preclude the development of nitrifying biomass. Several reasons have been proposed to explain this, with the key argument being that the efficient oxygen transfer afforded by the media design is sufficient to satisfy heterotroph and autotroph oxygen demand simultaneously.

Application of a simple ceramic filter to membrane bioreactor

A low-cost membrane bioreactor (MBR) would be an option for wastewater treatment in developing countries. A ceramic filter made of locally available materials was developed for arsenic removal from groundwater. The applicability of this filter to MBR for wastewater treatment was examined in this study. A hollow, cylindrical-shaped filter was made with the combination of 80% clay soil and 20% rice bran and fired at 900°C. The filter was submerged in acrylic cylindrical column reactors. Synthetic wastewater was fed into the reactors continuously, and the effluent from the filter was obtained by gravitational pressure with different mixed liquor (ML) heights and BOD loads. Efficient activated sludge separation and high organic removal performance were obtained. Lower flux and removal efficiencies were observed in the non-aeration mode. The flux performance was obtained 0.1–0.2m3/(m2.day) for up to one year of operation without clogging of the filter. Batch experiments were also performed to determine the relationship of the flux with the pressure and MLSS. A linear relationship between the flux and ML height was found, whereas the MLSS concentrations did not show a clear effect on the flux. This ceramic filter would be applicable to MBR facilities in developing countries.

Advance Oxidation of Sewage Water, Reclamation and Hygienization by Radiation Technology: A Novel Approach

First time in India, the present study was investigated the efficiency of electron beam to hygienise and oxidise the wastewater and focus on new technologies and processes. The use of electron beam accelerator to disinfect sewage water is gaining a great importance. The current emphasis on environmental health and water pollution issue are that, there is an increasing awareness in the process of disposing the waste water supply as well as beneficially. EB treatment of the waste water has found to be very effective in reducing the pathogens as well as BOD and COD load, indicating an increased in bio-degradability of waste water. EB dose of 1.5 kGy was sufficient for complete elimination of total coli forms. The experimental results elucidated that the percentage of reduction of BOD was 14 more as well as 32 % of reduction in COD with respect to increasing of irradiation doses(0.45 -6 kGy). So the irradiated sewage water can find its application either in agriculture for irrigation or in industry sector for cooling purpose or in both the sectors after flocculation treatment. Irradiation with electron beam is an unconventional to chlorination of municipal sewage water to provide disinfection.

Preliminary Study on Biomass Utilization and Water Management of Huai Luang River in the Huai Luang Basin, Udonthani Province, Thailand

The Huai Luang Basin is located in the Udonthani Province of Northeast Thailand. The basin is a repository of wastes coming from households, restaurants, hotels, agricultural lands, pig farms and other highly industrialized zones. Huge amounts of agricultural residues and wastes are left in the field annually. Most of the local farmers are poor and have never used modern technologies to utilize residues and wastes. There are areas where wastewater is being dumped directly into the river without any treatment. Not enough sewage plants in the cities as well as a lack of strong policies to regulate wastewater management have resulted in the Huai Luang River being classified as fair status and partly polluted, particularly in zone 2 of the municipality of Udonthani. These conditions can be attributed to high population density and industrialization. The water pollution is largely associated with land based activities such as urbanization, industrialization and agricultural. The major sources of pollution that pose problems for water quality in the basin are domestic sewage and agricultural activities, different amounts of pollutant loading depend on the ecological and socio-economic conditions in each zone. The main pollutants in zone 2 where the capital city is located come from household and industrial activities. In this paper, the biomass resources, water quality, the environment and land uses are examined and evaluated. Pollutants in terms of BOD loading from households and agricultural activities in the basin were estimated for the year 2006. An integrated approach to reduce pollutant discharge into the river is outlined. A mathematical model was also developed to encourage the adoption of biomass utilization technology to improve the water quality of the Huai Luang River. Based on the results, a policy to utilize biomass utilization technologies was determined to be a very effective tool to reduce environmental pollutants in the basin.JEL Classification: C61, Q01, R11

Correlation Analysis on the Runoff Pollutants from a Small Plot Unit in an Agricultural Area

This study was carried out to investigate the important factors relating to runoff and pollutant loads in a plot unit located in an agricultural area. Of the precipitation parameters, such as total precipitation, days since last rainfall (ADD, the rainfall was more than 10mm) and average rainfall intensity on runoff, the strongest effect was obtained due to total precipitation, but the rainfall intensity showed a slightly positive correlation. It was expected that both variables, i.e. total precipitation and rainfall intensity, would lead to the generation of greater runoff. In contrast, runoff was negatively correlated with ADD, which is understandable because more infiltration and less runoff would be expected after a long dry period. The TSS load varied greatly, between 75.6 and 5.18 x 104 g, per event. With the exception of TN, the TSS, BOD, COD and TP loads were affected by runoff. The correlations of these items were proportional to the runoff volume, with correlation coefficients (r) greater than 0.70, which are suitable for use as NPS model data. The TSS load showed very good relationships with organics (BOD & COD) and nutrients (TN & TP), with correlation coefficients greater than 0.79. Therefore, the removal of TSS is a promising factor for protecting water basins.

Septic Tank Effluent Treatment by Subsurface Horizontal Flow Wetland

Domestic wastewater treatment in Indonesia, mostly treat by using septic tanks. The use of septic tanks preferred by the public because of the design, construction, and maintenance are easy and more economical for the system of domestic wastewater disposal. Effluent from the septic tank still contains BOD about 100 mg /l, COD about 250 mg/l and TSS about 100 mg /l. This effluent is still dangerous to public health and is not fulfill wastewater effluent standards yet. If there is open space available, extended treatment of septic tank effluent can be done by field infiltration. This open space must suitable for infiltration without contaminating the ground water or well water. In urban areas with ground water level is high such as Surabaya, water infiltrate into the ground causing the problem. Problems that arise are due to pollution of ground water and surface water contaminated by effluent from the septic tank. Because of these problems, it would require an alternative treatment of septic tank effluent. Appropriate technology would be a simple, economical, easy in operation and maintenance. One of wastewater processing that can be applied to the septic tank effluent is a constructed wetland system. Previous research carried out by using Cyperus papyrus plant with sand media in batch experiments showed satisfactory results. In this study, experiments conducted by using Cyperus papyrus plant with sand media with continuous flow in a horizontal subsurface flow wetland method. Wastewater flows with varying flow 90 ml /min and 180 ml /min. The objective of this research is to determine the ability of a horizontal subsurface flow wetland for treating septic tank effluent. The parameters analyzed were BOD and TSS. The results show the relation of organic loading rate with BOD removal efficiency. The highest organic loading rate of 0.051 kg BOD/m2.d on first day observations has BOD removal efficiency of 73.63% and the lowest organic loading rate of 0.029 kg BOD/m2.d with an efficiency of 70.82%. This shows that BOD removal efficiency is affected by organic loading rate. If BOD loading rate increase, it will decrease BOD removal efficiency. Organic loading rate recommended for domestic wastewater is 0.037-0.4 kg BOD5 /m2.d. Although in this study the organic loading rate exceeds the above recommendations, but efficiency is still good, above 70%.

주남저수지 유역의 오염원과 수질변동에 따른 식물플랑크톤 군집

This study presented seasonal changes of the phytoplankton community in Junam reservoir by pollution and water quality of the lake. The water storage of the reservoir is 5.3 million ton, most of which are being utilized for agricultural, industrial and residential purposes. The annual precipitation during the investigation period was 1,868.9 mm, increasing by 20% from the average annual level of 1,506.7 mm in 2009. The annual average water storage was 57.3%. It decreased during agricultural season and then increased again after monsoon rainfall. The loads of BOD were <TEX>$3,799kgday^{-1}$</TEX>, and 81% of them came from livestock and household. The TN and TP loads were <TEX>$1,164kgday^{-1}$</TEX> and <TEX>$170kgday^{-1}$</TEX>, respectively, and 76% of them came from livestock. We assessed water quality of the Junam reservoir using 17 variables. According to the result, the reservoir met the fourth grade, meaning slightly bad, because of high concentration of COD, SS and chlorophyll-a. Eutrophication assessment was conducted by revised Carlson's Index (TSIm, Aizaki), and it was found that the entire lake was eutrophicated with high chlorophyll-a concentration all through the year, except during February to April and in July. A total of 76 phytoplankton species were identified from the samples. Among them, the largest number of species were Chlorophyceae with 33 species(43.4%), followed by Bacilliophyceae with 27 species(35.5%), Cyanophyceae with 8 species(10.5%), and Cryptophyceae with species(10.5%). The total cell number of phytoplankton was the highest in October(7,884 cells <TEX>$mL^{-1}$</TEX>) among Cyanophyceae and Bacilliophyceae. The seasonal succession of Chlorophyceae (Chlamydomonas spp.), Cyanophyceae(Microcystis aeruginosa) and Cryptophyceae(Rhodomonas spp.) was observed during January to May, July to September and October to December respectively.

Kinetics of enzymatic unhairing by protease in leather industry

In leather industry, unhairing is a heavy pollution operation. The conventional lime–sulfide process produces a large amount of sulfide which is toxic to health and difficult to dispose. Moreover, conventional lime–sulfide process leads to the destruction of the hair causing increased COD, BOD and TDS loads in the effluent. As an alternative method, enzymatic unhairing is a promising clean technology. The main utilized enzyme preparations are proteases. There are many reports about enzymatic unhairing, most of which are qualitative. The kinetics of enzymatic unhairing by protease was discussed in this article. It will provide useful information to enzymatic unhairing. In our research, by analysis of the concentrations of released total protein in enzyme bath during protease unhairing, the good linearity between released total protein and square root of time (min 1/2) was obtained at the initial stage. The good linearity suggests that enzymatic unhairing by protease is a diffusion-controlled process at the initial stage. The analysis of kinetics of released saccharides also confirms the same conclusion. On the other hand, the same characteristics between the kinetics of released saccharides and that of released total protein further confirms that it is the hydrolysis of core protein by protease that leads to the degradation of proteoglycans and the release of protein and saccharides. However, in our tests, the kinetics of released collagen indicates that the injury to skin took place in 3–6 h. Therefore, it’s necessary to control the time of protease unhairing within an appropriate limit.

Surahammar: a case study of the impacts of installing food waste disposers in 50% of households

This paper reviews 15 years of sewage works' monitoring data to assess the effect of installing in-sink food waste disposers (FWD) and how these effects compare with the published scientific literature. For the first time, it has been possible to assess at full scale the load/cost transfer from solid-waste to wastewater management. Within a period of 10 years, 50% of households in the town of Surahammar in Sweden chose to have FWD installed as their means of managing their kitchen food waste. The drainage from the households feeds a single wastewater treatment works (WwTW) that comprises primary settlement, activated sludge, followed by chemical phosphate precipitation and mesophilic anaerobic digestion. The sewer system is separate but with overflow between foul and surface water in times of surcharge; the diameters and gradients of the sewers are unexceptional. This paper reviews the influent and biogas monitoring data for the 21/2 years before installation started and the 10 years after the first peak of installations (by which time they had been installed in 30% of households). This provides a unique opportunity to verify the published research on FWD. The operational monitoring data are consistent with the already published research that FWD have little or no impact on water use, sewer blockages, vermin or wastewater treatment. The data are consistent with a hypothesis that in-sewer biological process acclimated to the change in wastewater composition and treated the dissolved and fine particulate load before it reached the WwTW. The digesters produced 46% more biogas than before FWD were installed (P=0.01). There was no significant increase in hydraulic load, or in the loading of BOD 7 , COD, N or NH 4 . As a result of Surahammar's overall waste strategy, not just the FWD, but the tonnage of waste to landfill from the municipality has also decreased from 3600 tonnes/ year in 1996 to 1400 tonnes/year in 2007.

강우 초기특성에 따른 비점오염부하량 산정을 위한 FFC2Q 모형

이 연구에서는 FFC2Q모형의 WQUAL블럭의 기본이론과 적용성을 검토하고, 도시지역의 강우초기 시 집중적으로 발생하는 CSOs의 비점오염부하 특성을 분석하였다. 또한 비점오염물 축적량 산정법과 쓸림방정식에서 주요 매개변수들의 선택과 그 영향을 분석하였다. 군자 배수구역의 3개 강우사상에 대한 실측치와의 비교를 통해 첨두유출량, 총유출량, 총부하량, 첨두농도 발생시간 등을 적정하게 모의할 수 있었으며, 입력자료의 단순화에도 불구하고 SWMM, MOUSE 등과 대등한 계산 결과를 보였다. 강우분포와 관련하여서는, 초기에 집중도가 높은 Huff1 분포에서 오염부하가 다른 분포에 비해 빠르게 발생하였으며, 강우초기 <TEX>$BOD_5$</TEX>, COD의 부하량 증가율은 SS에 비해 크게 나타났다. 비점오염부하량은 일정 강우 초기에 집중되어 결국 총부하량에 이르며, 이후 강우지속에 따른 유출은 비점오염부하량에 큰 영향을 미치지 못하는 것으로 분석되었다. We study the basic theory and applicability of the WQUAL block in the FFC2Q model and the characteristics of non-point pollutant loads during the early stage of runoff. Study is also performed on selection of the values of the related parameters and their effect on the simulation results. FFC2Q simulation results are compared for verification with the measured data for three rainfall events in the Gunja Subbasin and found to be similar to the measured data in peak-flows, total runoff volumes, total loads, peak concentrations and times of peak concentration. This model thus shows results very close to those applying the SWMM and MOUSE models, even though it uses simplified input data. Related to rainfall distribution, under the condition of Huff 1st quartile distribution the pollutant loads occurred earlier than under other conditions, and in the early stage of rainfall the BOD and COD loads increased faster than the SS loads. The NPS loads were concentrated in the early stage of rainfall and finally reached total loads, so the rainfall after that could not contribute so much to the NPS loads.

Managing water quality of River Yamuna in NCR Delhi

River Yamuna is a typical example of degraded lotic ecosystem which has been turns into a sewage drain in Delhi National capital region due to anthropogenic pressure and aggravating pollution load. Delhi is alone responsible for 79% of the entire pollution load in the said river. The drain discharges exerting a massive BOD load of hundreds of tons per day into the river. The pollutants could not get diluted as the river has very little or no flow in non-monsoon months due to lack of indigenous water. Water quality index reveal that before entering Delhi, river water has the medium water quality, gets severely polluted in Delhi, shows very bad water quality which continues till Agra Canal. Improper location of STPs and mismatch between the available treatment capacities of STPs with the actual sewage generation results muddle up of “approx” 60% untreated wastewater into the River Yamuna. Implementation of sustainable management plan with already available facilities, proper sewerage planning and maintaining the minimum ecological flow will control the pollution in River Yamuna.

Unit BOD Load of Cooked Food Waste

Unit BOD Load of Cooked Food Waste

Results of benchmarking at 7 larger WWTP operators in Denmark

In this ongoing project, the process at 15 medium to large WWTPs is compared using benchmarks. The influent COD load was found to be the best predictor of the sludge TS amount in the dewatered sludge. The best predictor of the total electricity use was the total N influent load. The BOD5 load was a poor predictor of both. The standard population equivalents were also found to be poor predictors of the influent loads. For some plants, the influent load can be much as 4 times greater than the load predicted by the PE. For other plants, the influent load was 30-50% less than the load predicted by the PE. This load variation is due to the industrial load. A comparison of the type of aeration equipment used showed that the electricity consumption of diffuser aerators was about 35% lower than for surface aerators. More than 40% of electricity used is for aeration. Therefore there is a large potential for saving electricity by switching to diffuser aeration.

Assessment of classical surface organic loading design equations based on the actual performance of primary and secondary facultative ponds

This article presents results from a performance evaluation of 73 full-scale primary facultative ponds and 37 secondary facultative ponds in Brazil. The data were used to test the applicability of some classical design equations for recommended surface BOD loading rates. The empirical equations proposed by Mara in 1976 and 1987 and the equation developed by McGarry and Pescod in 1970 were evaluated. The loading and hydraulic operating conditions were also evaluated to support the analysis of the influence of the parameters surface BOD loading (L(s)) and hydraulic retention time (HRT) on the performance of the ponds. The results showed that the design equations proposed by Mara showed good applicability for primary facultative ponds, representing good indicators of the limit value of loading rates to be applied on the units. But the secondary facultative ponds showed good and poor performances for all loading rates and the best ponds, in general, were not those which followed the design equations recommendation. Finally, the influence of the actual loading conditions on the ponds performance was very small and scattered, indicating that other unquantified design and operational aspects were playing an important role.

Vermiculture Technology: Reviving the Dreams of Sir Charles Darwin for Scientific Use of Earthworms in Sustainable Development Programs

Vermiculture technology is emerging as an “environmentally sustainable”, “economically viable” and “socially acceptable” technology all over the world. 1) Vermi-composting Technology (to manage most organic wastes); 2) Vermi-filtration Technology (to treat municipal & several industrial wastewater); 3) Vermi- remediation Technology (to treat & clean up contaminated lands); 4) Vermi-agro-production Technology (to produce chemical-free organic foods by worms & vermicompost); 5) Vermi-industrial Production Technology (to produce valuable industrial raw materials from worms). The use of earthworms as “waste managers” for efficient “composting of food and farm wastes” and as “soil managers” for “fertility improvement” and enhanced “farm production” were known for ages but now it is being more scientifically and also commercially revived. The other uses of earthworms for the benefits of environment and society (wastewater treatment, land remediation & production of valuable medicines even to combat cancer and heart diseases; raw materials for rubber, lubricant, soap, detergent & cosmetic, industries and protein rich feed materials for fishery, dairy & poultry industries are some “new discoveries”. We have successfully experimented with the first four technologies for management of “municipal solid wastes”, treatment of “municipal & industrial wastewater”, remediation of “PAHs contaminated soils” and production of “wheat & corn crops” by use of vermicompost at Griffith University, Australia, with excellent results. Wastes are degraded by over 75% faster than conventional systems and compost produced are disinfected, detoxified, richer in nutrients & beneficial soil microbes; BOD loads & TSS of wastewater is reduced by over 95%; PAHs from contaminated soils are removed by over 80% in just 12 weeks; and crops growths are promoted by 30-40% higher as compared to chemical fertilizers. Earthworms are both “protective” & “productive” for environment and society.

Earthworms: Charles Darwin’s ‘Unheralded Soldiers of Mankind’: Protective &amp;amp; Productive for Man &amp;amp; Environment

Earthworms promises to provide cheaper solutions to several social, economic and environmental problems plaguing the human society. Earthworms can safely manage all municipal and industrial organic wastes including sewage sludge and divert them from ending up in the landfills. Their body work as a ‘biofilter’ and they can ‘purify’ and also ‘disinfect’ and ‘detoxify’ municipal and several industrial wastewater. They reduce the BOD & COD loads and the TDSS of wastewater significantly. They can even remove the EDCs (endocrine disrupting chemicals) from sewage which is not removed by the conventional sewage treatments plants. Earthworms can bio-accumulate and bio-transform many chemical contaminants including heavy metals and organic pollutants in soil and clean-up the contaminated lands for re-development. Earthworms restore & improve soil fertility by their secretions (growth hormones) and excreta (vermicast with beneficial soil microbes) & boost ‘crop productivity’. They have potential to replace the environmentally destructive chemical fertilizers from farm production. The ‘protein rich’ earthworm biomass is being used for production of ‘nutritive feed materials’ for fishery, dairy & poultry industries. They are also being used as ‘raw materials’ for rubber, lubricant and detergent industries. The bioactive compounds isolated from earthworms are finding new uses in production of ‘life saving medicines’ for cardiovascular diseases and cancer cure.

Treatment of domestic wastewater in a pilot-scale HSFCW in West Iran

This research investigated the feasibility of using constructed wetland system with a second-stage processing, included duckweed lagoon as a polishing stage, as an appropriate technology for treating the domestic wastewater generated by small communities in the economical underdeveloped cold regions. The reed bed pilot included four basins, of which two were used to plant reed and the two others as witness. The duckweed pilot was set up near the reed beds. The pilot plant was tested with six different BOD, COD, TN, TP, TSS and TDS loadings. The test results showed the artificial reed bed with subsurface flow capable of removing TSS by 92%, BOD by 89% and COD by 78%. Moreover it is possible to remove phosphorus and nitrogen containing compounds by 29% and 35%, respectively. The reed bed effluents were discharged into duckweed lagoon and the removal ratios of the above parameters were once again studied. The results showed reductions of 20% in BOD, 10% in COD, 24% in TSS, 8% in TN and 29% in TP. Based on these studies, the use of artificial reed beds for treating household wastewater in small communities is a sound technical and economical solution, while duckweed can be used as a complementary post-treatment process during the warm seasons.

Kinetic modelling of organic matter removal in 80 horizontal flow reed beds for domestic sewage treatment

This paper reports a comparative study of four kinetic models that can be applied in the design of subsurface horizontal flow reed beds for wastewater treatment. The models were developed from different combinations of Monod kinetics, first-order kinetics, continuous stirred-tank reactor and plug flow patterns. Using three statistical parameters (coefficient of determination, relative root mean square error, and model efficiency), critical examinations were made on the accuracy of these models. For predicting organic matter removal, the combination of Monod kinetics with plug flow pattern gave the closest match between theoretical predictions and actual performances of 80 horizontal flow reed beds. In all four models, the coefficients of BOD removal were found to increase slightly with BOD loading. The ratios of BOD/COD had no correlation with the coefficients, indicating that in the horizontal flow reed beds the degradation of organic matter is insensitive to the nature of organics in the wastewater.

Hydrodynamic-ecological model analyses of the water quality of Lake Manzala (Nile Delta, Northern Egypt)

Lake Manzala remains the largest of the Nile Delta lakes and has undergone substantial recent changes particularly over the last 30 years due to regulation of freshwater inflows, land reclamation and increasing loads of BOD and nutrients. The latter are particularly associated with polluted drains flowing into the lake. An increasing fraction of the N load may also come from the expanding fish farming industry within and around the lake. Over the past 20–25 years, the N load from the drains has increased three times whilst the P load has remained approximately constant. This is despite a 40% reduction in freshwater inflows due to diversion of water towards the Sinai for land development. As a result of these changes, the concentration of total N in the drains has increased 4.5 times while the total P concentration has increased by 50% over the same period. Increases in nutrient concentrations can be attributed to increase in the use of fertilizer combined with an expanding population served by sewers, improved living standards and increased industrial production. Nutrient enrichment has resulted in declining water quality and eutrophication, especially in the southern parts of Lake Manzala. A combined hydrodynamic-ecological model has been set up for the lake and is used to analyse the development of water quality as a function of the load of organic material and nutrients. Model results show that 86% of the N load and 59% of the P load are retained within the lake. Despite the efficient treatment of wastewater by the lake ecosystem, approximately 6,000 tonnes of N and 1,300 tonnes of P are exported to the Mediterranean through the two main lake–sea connections. This nutrient export has important implications for coastal fisheries production. The present investigation suggests that the current anthropogenic nutrient load to the coastal zone exceeds that of pre-Aswan High Dam conditions despite large reductions in the annual pulse of water and nutrients brought about by the dam. A series of model simulations with reduced nutrient load are investigated in order to identify the conditions required to enable the propagation of vegetation throughout the lake. Submerged rooted vegetation is used as an indicator for water quality as it needs light for growth and in polluted, eutrophicated waters turbidity increases hampering vegetation growth. Simulation results indicate that the nutrient load has to be reduced to approximately 25% of the present loads if submerged rooted vegetation is to become re-established in the more polluted south eastern parts of the lake.