Aykut Karadeniz

Gas/particle partitioning of PCDD/F compounds in the atmosphere of Istanbul

Gas/particle partitioning of polychlorinated dibenzo-p-dioxin (PCDD) and polychlorinated dibenzofuran (PCDF) compounds in the ambient atmosphere were investigated at three different sites (urban-industrial, urban and sub-urban) in İstanbul. Average gas and particle phase concentrations were measured as 133fgm(-3) and 1605fgm(-3), respectively. Gas phase concentrations of polychlorinated dibenzo-p-dioxin/furan (PCDD/F) compounds were determined to be 128fgm(-3), 50fgm(-3), 153fgm(-3) during summer season and 204fgm(-3), 164fgm(-3), 154fgm(-3) during winter season for the respective three sampling sites. Particle phase concentrations were determined to be 287fgm(-3), 176fgm(-3), 160fgm(-3) during summer and 6586fgm(-3), 2570fgm(-3) and 1861fgm(-3) during winter season for those three sampling sites. Chlorination level and molecular weight of congeners affected gas/particle partitioning of PCDD/F compounds. Gas phase percentages of 2,3,7,8-TCDD and OCDD concentrations were determined to be 47% and 1% respectively. A relatively high correlation was found between total particle matter (TPM) and particle phase PCDD/F concentration during winter season.

Investigating Biomass Formations at Different Depths in a Slow Sand Filter

A laboratory-scale slow sand filtration (SSF) system was used to investigate biomass formation in different depths of SSF depending on various operating conditions in regard to filtration rate and influent iron-manganese concentrations. Results suggest that biomass formation occurs mainly in the uppermost 1.5 cm of the filter bed with slight contributions from layers between 1.5 cm and 14.5 cm. The highest volatile solids (VS) accumulation was observed in the uppermost layer as 16.93±0.07 mgVS/g dry sand, and the accumulation was found to be a function of both filtration rate and influent iron-manganese concentrations. Hydraulic conductivities were tested as a measure of biomass formation. The highest initial value of hydraulic conductivity was measured as 13.7 μm/s, while the lowest values ranged from 3.28 to 6.62 μm/s at the end of 55 days of operation. Hydraulic conductivities of the upper layers decreased quickly with time, while slight reductions were observed in hydraulic conductivities of the lower layers.

An MS excel add-in for teaching hydraulics of pipe flow in engineering curricula

This paper presents implementation of an MS Excel add‐in incorporating Visual Basic for Applications for teaching pipe flow calculations in undergraduate and graduate level. The add‐in contains a total of 108 functions for several purposes ranging from continuity equation to branching pipes and pipe network problems. Tip texts and a number of userforms were developed for easy use of the tool. A users guide was also prepared that includes the theory of hydraulic calculations and numerical methods involved. Being an add‐in for MS Excel, the tool is a perfect candidate for implementing as an educational tool in undergraduate and graduate level education.

An MS Excel tool for water distribution network design in environmental engineering education

An MS Excel tool for teaching hydraulic analysis of water distribution networks (WDNs) was developed. The tool is able to perform both steady‐state and extended period simulations of a WDN. The tool does not require installation and offers a portable solution to WDN design problem in undergraduate environmental engineering studies.