Review of the technological approaches for grey water treatment and reuses
ABSTRACT Based on literature review, a non-potable urban grey water reuse standard is proposed and the treatment alternatives and reuse scheme for grey water reuses are evaluated according to grey water characteristics and the proposed standard. The literature review shows that all types of grey water have good biodegradability. The bathroom and the laundry grey water are deficient in both nitrogen and phosphors. The kitchen grey water has a balanced COD: N: P ratio. The review also reveals that physical processes alone are not sufficient to guarantee an adequate reduction of the organics, nutrients and surfactants. The chemical processes can efficiently remove the suspended solids, organic materials and surfactants in the low strength grey water. The combination of aerobic biological process with physical filtration and disinfection is considered to be the most economical and feasible solution for grey water recycling. The MBR appears to be a very attractive solution in collective urban residential buildings.
SourceAvailable from: Mona S. Mohamed-Mansour[Show abstract] [Hide abstract]
ABSTRACT: Pharmaceutically active compounds (PhACs) are excreted by humans with urine mainly and, to a lesser extent, with faeces. This study investigates the effect of Fenton’s oxidation on the degradation of three PhACs, namely levofloxacin, ibuprofen and atorvastatin in combination. Therefore, aqueous solution and urine spiked, separately, with the selected PhACs. Fenton and Fenton-like oxidation treatments, namely: (H2O2 and FeSO4), (H2O2 and CuCl) and (H2O2 and Activated Carbon) were examined in batch reactors. Results showed that the removal rate ranged from 95 to 99% for the PhACs and from 97 to 98% for the COD in the aqueous solution. For the artificially contaminated urine, the removal rate ranged from 95 to 99% for the PhACs and from 97 to 99% for the COD. Biodegradability (BOD5/COD ratio) improved from 0.09 to 0.5 - 0.7, indicating that the effluent was amenable to biological treatment.
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ABSTRACT: A growing implementation of greywater reuse (GWR) pract ices may lead to bene fits on the wastewater side of the urban water cycle. In addition to the positive effect in decreasing urban water demand, GWR changes the quantity and quality characteristics of domestic wastewater released to sewers and conveyed to wastewater treatment plants. Coagulant selection is not an easy task because one coagulant can remove efficiently the suspended solids but at the same time increase the conductivity. This makes the final select ion of coagulants very dependent on the relative importance assigned to each measured parameter. In this work, experiments were carried out using wastewater composed by domestic water, powder soap and kitchen oil in similar quantities of water emp loyed for washing dishes. Measurements of pH, electrical conductivity, temperature, total solids and dissolved oxygen were done by analyzing a sample o f 50 mL fro m the final suspension. It was used a tradit ional method of coagulation and decanting treatment using some different volu me of solutions such as a lu min iu m sulphate (concentration of 1000 and 2000 mg/ L), Fe II sulphate and alumin iu m tripoliphosfate with concentration of 2000 mg/ L. According to the findings it could be observed that aluminiu m sulphate provided good results, reducing total solids and not causing changes in the other parameters, fo r examp le, results of pH and dissolved o xygen for the treated water kept close d to the tap water.
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ABSTRACT: The present study focuses on the decolourization of crystal violet (CV) using TiO2 supported on glass slides under natural sunlight (sunny days, June 2013). The commercial Degussa P25 TiO2 was used as a photocatalyst in this study. The P25 TiO2 deposition process was achieved using acetone as precursor. The effect of some process parameters (CV concentration, number of TiO2 glass slides, pH and presence of metallic cations as interfering ions such as Cu2+, Fe2+, Fe3+, Mn2+ and Zn2+) was investigated. It was found that the decolourization process follows a pseudo-first order with respect to the substrate concentration. The pH had a net effect on the decolourization process. The apparent rate constants increased proportionally to the number of TiO2 glass slides. The results show that the presence of Fe2+, Mn2+ and Cu2+ cations with CV decreases the decolourization rate by varying degrees (22.1–35.3%) while Zn2+ has a negligible effect. However, the presence of Fe3+ led to an acceleration of the CV decolourization. The P25 TiO2-supported can be reused several times under the present working conditions. Finally, the photoactivity efficiency of P25 TiO2-supported was compared to that of P25 TiO2-dispersed under artificial UV (single lamp, 300–400 nm) and natural sunlight. Under the present experimental conditions, a complete decolourization was achieved less than 6 h of solar irradiation at natural pH and using two TiO2 glass slides.Desalination and water treatment 12/2013; DOI:10.1080/19443994.2013.873354 · 0.99 Impact Factor