Boets, Pieter

Donoso Pantoja, Natalia Carolina

Gobeyn, Sacha

Goethals, Peter

Meers, Erik

Villa Cox, Gonzalo Gabriel

English

Ghent University Academic Bibliography

ECOLOGICAL RELEVANCE OF THE DISCHARGE STANDARD LIMIT OF CHEMICAL OXYGEN DEMAND FOR CONSTRUCTED WETLANDS TREATING ANIMAL MANURENatalia Donoso 1,2,*, Sacha Gobeyn 2, Gonzalo Villa-Cox 3, Pieter Boets 2, Erik Meers 1, and Peter L. M. Goethals 21 Department of Applied Environmental Chemistry, Ghent University, Coupure Links 653, 9000 Ghent, Belgium2 Department of Applied Ecology and Environmental Biology, Ghent University, Coupure Links 653, 9000 Ghent, Belgium3  Department of Agricultural Economics, Ghent University, Coupure Links 653, 9000 Ghent, BelgiumThe studied ecological water quality indicators are estimated to respond more to BOD5 rather than COD concentrations. Thus, to define properstandard limits, models with high explanatory and predictive power need to be developed based representative ecological information in combinationwith abiotic data. For this, the selected sampling locations should be periodically monitored and at the same frequencies.The presence of recalcitrant COD (e.g. in form of humic substances in CWs) make this a non-sensitive parameter. Future research suggest thedevelopment of a more sensitive legislation around BOD5 or other (to be developed) parameters correlated with organic pollution analysed in areliable and high-throughput manner. So that the implementation of CWs could be promoted in Flanders and agricultural intense areas.* nataliacarolina.donosopantoja@ugent.beIntroduction MethodologyResultsObjectives• Evaluate the response of the water quality index, called MultimetricMacroinvertebrate Index Flanders (MMIF) and organic pollution sensitivetaxa as a function of water quality parameters through statisticalregression models.• Investigate the limitations and practicality to define proper standard limitsregarding the status of aquatic systems.Conclusions 1. Site selection: Fresh and brackish small polder watercourses andcase study CWs located in Flanders -Belgium.2. Data exploration of water quality of selected sites and presence oforganic pollution sensitive taxa regarding environmental anddischarge standard limits as a function of the MMIF classes (bad, poor,moderate, good, high).3. Statistical regression models development predictor variables: pH,conductivity, COD, biological oxygen demand (BOD5), dissolved oxygen(DO), total nitrogen (TN), nitrate (NO3), ammonia (NH4) and totalphosphorous (TP) concentrations; response variables: MMIF andpresence of organic pollution sensitive taxa.4. Selection of the optimal model configuration through stepwiseselection procedure.5. Estimation of marginal effects i.e𝝏𝑴𝑴𝑰𝑭𝒍𝒕𝝏 𝒑𝒓𝒆𝒅𝒊𝒄𝒕𝒐𝒓 𝒗𝒂𝒓𝒊𝒂𝒃𝒍𝒆of the predictorvariables on the variance of the MMIF means and the probability ofoccurrence of organic pollution sensitive taxa. Study period 1989 - 2016.Figure 1: A. BOD5, B. COD concentrations recorded in fresh and brackish polder watercourses compared to the environmental standard limits of 6 mgO2.L-1, 30 mgO2.L-1 respectively and ranking score MMIF classes.Figure 2: Example of sensitive taxa present in the polder watercourses in relation to the environmental standard limits for A. BOD5, B. COD .Table 1: Example of estimated marginal effects on the MMIF means given the mean concentrations of water quality parameters determined at the Yserriver basinHow we calculated the estimated marginal effects of BOD5 and COD on the ecological quality (MMIF)?Average concentrations used as input on equation a) and b) Estimated marginal effectBasinBOD5 COD DO EC NH4 pH TSS BOD5 CODmg.L-1 mg.L-1 % mS.cm-1 mg.L-1 Units mg.L-1Yser River 5.6 52.3 66.4 1325 0.4 7.9 26.3 -0.021 0.0026Data exploration A BBad      Poor   Moderate  Good/High Bad      Poor   Moderate  Good/HighGood and High ecological status at high COD concentrations?Not as sensitive to high COD concentrations as expected?BANegative and 10 times higher than COD = -0.0311 – 0.0032*[NO3it] – 0.0003*[TSSit]+0.0002*[DOit]+4.73x10-6[ECit]+0.0027*[NH4it]= 0.0033 – 4x10-5*[DOit] + 0.0001*[TSSit]

Ecological relevance of the discharge standard limit of chemical oxygen demand for constructed wetlands treating animal manure

https://biblio.ugent.be/publication/8544698/file/8544701

Ecological relevance of the discharge standard limit of chemical oxygen demand for constructed wetlands treating animal manure

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