D10: Impact of Contaminants - Hydromod

More documents

Recommendations

Info

Integrated Water Resource Management for Important Deep European Lakes and their Catchment Areas EUROLAKES D10: Impact of Contaminants Analysing results of the filtered matters from the wastewater samples FP5_Contract No.: EVK1-CT1999-00004 Version: 4.0 Date: 25/07/01 File: D10-vers.4.0.doc Page 102 of 136 Phthalates • In 50-60% of the samples Di(2-ethyhexyl)phthalate- and Dibutylphthalate concentrations were detected. • Dimethylphthalate and Diethylphthalate could be detected only scarcely, Butylbenzylphthalate could not be detected in any of the samples. Organo-tin-compounds • In the solid matters of 40 % of the analysed samples Tributyltin could be detected above the detection concentration. • Only in 20 % of the samples Dibutyltin could be detected, and Monobutyltin could only be detected in one single sample. Nonylphenolethoxylates (NP1EO, NP2EO) • In the solid matters of 75 % of the analysed samples Nonylphenole could be analysed • NP1EO and NP2EO was found in 50% and 40% of all analysed samples. Mostly the concentration of NP1EO was found above the concentration of NP2EO. The effect of wastewater treatment on steroid hormones and Alkylphenolpolyethoxylates in particular The only publication regarding more detailed reduction pathways of endocrine substances in sewage treatment plants is from [KREUZINGER, 1998]. He summarises publications on steroid hormones and Alkylphenolethoxylates and comes to the following results: Effect of wastewater treatment processes on Steroid Hormones Estrogens are collected in the sewer system and reach the wastewater treatment plants most probably in their biologically less effective conjugated form [UMWELTBUNDESAMT BERLIN, 1995] Considering the decomposition properties of other complex compounds during treatment of wastewater [GIGER, AHEL, KOCH, 1986;MARCOMINI, 1989; AHEL], it may be assumed that the further degradation of estrogens in wastewater treatment plants is strongly depending on the processes and mode of operation applied in the sewage works. [FÜRHACKER, 1998] and [SCHWEINFURTH, 1997] summarise the decomposition of EE2 in wastewater and environment as follows: After incubation of EE2 – and also mestranol – with activated sludge under aerobic conditions over a duration of 5 days Norpoth et.al. (1973) noticed a reduction in the concentration of theses substances.
Integrated Water Resource Management for Important Deep European Lakes and their Catchment Areas EUROLAKES D10: Impact of Contaminants FP5_Contract No.: EVK1-CT1999-00004 Version: 4.0 Date: 25/07/01 File: D10-vers.4.0.doc Page 103 of 136 [TABAK and BUNCH ,1970] noticed a reduction of 95 % of EE2 (20mg/l) at continuous incubation with activated sludge after a period of 4 weeks, whereas with adapted microorganisms within 3 weeks a reduction of 97 % and after 4 weeks a full primary reduction was noticed. It seemed that the substances were in an initial stage adsorbed to the activated sludge flocks. As has been expected EE2 showed to be more stabile under these conditions than the endogene estrogenes estradiole, estron and estriol. [TABAK et al., 1981] further conducted a field study in several wastewater treatment plants (n=12-14) in the United States, investigating the degradation of different Stereoidhormones. They reported a reduction of 20-40 % in the course of the wastewater treatment. Considering the analytical procedures applied under this study, it is assumed that the measured concentrations also include conjugated metabolites of EE2, so that the percentage of actually eliminated free compounds is even higher. Adsorption to activated sludge particles might mainly contribute to the reduction of concentrations. Considering the structure of EE2 it is assumed that hydrolysis and photolysis processes are of minor contribution to the elimination of EE2. As can be seen, important information on process parameters like age of the incubated sludge, waste load, origin (from which process) of the sludge is very scarce and does not allow any statements on the performance of existing treatment plants designed according to the current state of the art. Another problem is that the state of the applied technology in wastewater engineering has changed considerably since the 80ies. Effect of wastewater treatment processes on Alkylphenolpolyethoxylates (NPnEOs) There exists a number of detailed research works on the behaviour of NPnEOs in the biological wastewater treatment process which have been conducted by the EAWAG in Switzerland. [AHEL.et.al 1994, BRUNNER et.al 1984, GIGER et al 1984, MARCOMINI at.al 1988, SIEGRIST et.al.1989]. The following paragraphs summarise the results and findings of these Swiss research works and are based on the recently published pathways for the decomposition of NPnEOs [published by CORCIA et.al 1998]. Transformation of NPnEOs in sewer system and mechanical wastewater treatment According to [GIGER,1986], and AHEL (1994) the distribution of NPnEOs in the analysed raw water influents to sewage treatment plants did not significantly differ from the distribution of the primary sedimentation tanks effluent. (Refer to Figure 11-2) However the concentrations in short chain NPnEOs is changed considerably. This could be explained by the fact that short chain NPnEOs are more hydrophobe and are Therefore easier adsorbed to non dissolved wastewater particles which settle in the primary sedimentation tank and are sourced out with the primary sludge.
Page 1 and 2:
Integrated Water Resource Managemen
Page 3 and 4:
Page 5 and 6:
Page 7 and 8:
Page 9 and 10:
Page 11 and 12:
Page 13 and 14:
Page 15 and 16:
Page 17 and 18:
Page 19 and 20:
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
Page 31 and 32:
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
Page 41 and 42:
Page 43 and 44:
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52: Integrated Water Resource Managemen
Page 101: Integrated Water Resource Managemen
show all

D10: Impact of Contaminants - Hydromod

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?