Grey water biodegradability

Knowing the biodegradability characteristics of grey water constituents is imperative for a proper design and operation of a biological treatment system of grey water. This study characterizes the different COD fractions of dormitory grey water and investigates the effect of applying different conditions in the biodegradation test. The maximum aerobic and anaerobic biodegradability and conversion rate for the different COD fractions is determined. The results show that, on average, dormitory grey water COD fractions are 28% suspended, 32% colloidal and 40% dissolved. The studied factors incubation time, inoculum addition and temperature are influencing the determined biodegradability. The maximum biodegradability and biodegradation rate differ between different COD fractions, viz. CODss, CODcol and CODdiss. The dissolved COD fraction is characterised by the lowest degradation rate, both for anaerobic and aerobic conditions. The maximum biodegradability for aerobic and anaerobic conditions is 86 and 70% respectively, whereas the first order conversion rate constant, k 20, is 0.119 and 0.005 day?1, respectively. The anaerobic and aerobic conversion rates in relation to temperature can be described by the Arrhenius relation, with temperature coefficients of 1.069 and 1.099, respectively.Water ManagementCivil Engineering and Geoscience

Evaluation of Heterogeneous Photocatalytic Treatment for Reuse of a Hotel's Greywater

Reuse of greywater for non-potable purpose such as irrigation, toilet flushing and groundwater recharge has been evaluated and applied widespread after advanced treatment processes. Specifically advanced oxidation processes present alternative option to integrate with biological treatment as prior or post-treatment to remove recalcitrant organic matters of emerging concern in greywater. This study focuses on the efficiency assessment of heterogeneous photocatalysis (PC) for oxidative degradation of real greywater samples collected at a hotel in Antalya, Turkey, by means of dissolved organic carbon (DOC) and UV254 absorbance removals that correspond the mineralization and degradation rates, respectively. Increasing TiO2 dose from 0.1 to 1 g/L enhanced DOC removal rates. Reduction of suspended solids from greywater using 0.45 microfilters increased DOC removal from 27 to 35% during PC treatment