Lana Mahmoud

Abstract

Fresh water scarcity continues to present itself as an underlying global problem as we steadily approach 2025 (UN 2006). Egypt is no exception to the rule, facing several water pollution problems extending from all sectors in the country and negatively affecting water quality and public health. According to the Ministry of Water resources and irrigation (1997), the average water uses in the Egyptian household comprises 18% for shower and bath, 18% for toilet flushing, 8% for laundry, 14% for dishwashing and drinking, 10% for cooking, 30% for irrigation and 2% for other activities which makes onsite treatment and reuse of greywater an attractive option to bridge the gap between water demand and supply in Egypt and help build biophilia settlements that are ecological and sustainable. The main research aim of this work was to study the potential of water hyacinth for removal of organic pollutants and pathogens from residential greywater using aquatic filtration pilot scale system in order to yield water suitable for irrigation of residential lawns. The different experiments of the current work were conducted in five phases at the facilities of the American University in Cairo (AUC). In Phase I, synthetic greywater was formulated in the lab to run the different experiments of the study by mixing tab water with different chemicals that simulate the different contaminants commonly present in greywater and it was observed that the water quality parameters of the synthetic greywater stimulated in the current study were within the range of the values of water quality parameters reported in literature for light and heavy greywater. In Phase II, water hyacinth, papyrus reed and common reed were used to investigate the effectiveness of treating synthetic greywater compared to a control (no plant condition). It was found that over the period of 19 days, water hyacinth was able to remove a total mass of 83 mg TDS (45% higher than the control sample), 0.5 mg PO4- (60% higher than the control sample), 53 mg COD (5.7% higher than the control sample) and 572 mg FC (44% higher than the control sample) and was able to achieve the lowest greywater normalized evaporation rate with a total of 0.114 liter of water per kg of plant wet mass per day (l/kg.d). Common reed was found most effective in treating organic and suspended pollutants, compared to water hyacinth and papyrus reed. However, the planting cost, removal operation and overall management is considered favorable to water hyacinth over the other two plant species. In Phase III, the effect of different hydraulic loading rates on the treatment performance of synthetic greywater was investigated using similar wet densities of water hyacinth. it was observed that 20 days of experiment, water hyacinth in Reactor 5 (HLR = 0.29 m3/m2/d) was able to reduce the turbidity, TSS, COD and BOD5 of greywater from 176 NTU to 14 NTU+7 NTU, 294 mg/l to 20 mg/l+13.5 mg/l, 176 mg/l to 16 mg/l+12 mg/l and 102 mg/l to 7 mg/l+6 mg/l (on average basis), respectively. It was also observed that the operation of the treatment system at HLR of 0.29 m3/m2/d results in an effluent organic quality (BOD5 and COD) that complies with the limits reported in the Egyptian Code of Practice for Reuse in Irrigation; Category A (501-2015). Reactor 5 (HLR = 0.29 m3/m2/d) was also able to withstand hydraulic shock loading with a turbidity removal rate of 68.4%, TSS removal rate of 54.1%, COD removal rate of 39.8% for the first four hours and a removal efficiency of 86.8%, 63.9% and 80.6%, respectively for the next twenty hours. In Phase IV, the effect of different wet densities of water hyacinth on the treatment of synthetic greywater was investigated using similar hydraulic loading rates. It was observed from the experiment that lasted 20 days that water hyacinth in Reactor 5 (Wet density = 4.345 kg/m2) was able to reduce the turbidity, TSS, COD and BOD5 of greywater from 28 NTU to 7 NTU+3.3, 20 mg/l to 4 mg/l+1.7 mg/l, 54 mg/l to 16 mg/l+4.1 mg/l and 37 mg/l to 10 mg/l+2.8 mg/l (on average basis), respectively. Water hyacinth in Reactor 4 (Wet density = 2.173 kg/m2) was also able to reduce the turbidity and TSS of greywater from an average of 28 NTU to 10 NTU+3.7 and from 20 mg/l to 5.5 mg/l+2.9 mg/l, respectively. In Phase V, the performance of the aquatic filtration system in treating real greywater when using the optimum operating conditions obtained from Phase III and Phase IV was investigated. The greywater treatment system which operated for a period of 29 days at HLR (0.29 m3/m2/d) and highest wet plant density (2.173 kg/m2) was able to reduce the turbidity, TSS, COD and BOD5 of greywater from 82 NTU to 54 NTU+20 NTU, 52 mg/l to 34 mg/l+24 mg/l, 366 mg/l to 217 mg/l+71 mg/l and 222 mg/l to 129 mg/l+43 mg/l (on average basis), respectively. The validation of this synthetic effluent by comparison with real greywater demonstrates that the designed and constructed aquatic filtration system using water hyacinth is a promising, low-cost, low-tech greywater treatment system that can be run and maintained by unskilled operators. However, the improvement in treatment in the Water Hyacinth based system is of particular significance considering the strict effluent quality standards recently imposed by the Egyptian Code for Landscape Irrigation. Hence, future research (including scale economic studies) should be carried out to investigate the use of greywater at the community level with the optimization of different techniques that could further enhance the greywater effluent quality to the permissible level of 1st group (i.e. advanced treated water) as unrestricted water reuse in landscape irrigation according to the "Egyptian Guidelines".

Department

Environmental Engineering Program

Degree Name

MS in Environmental Engineering

Graduation Date

2-1-2019

Submission Date

September 2018

First Advisor

El-Haggar; El-Gendy, Salah; Ahmed

Committee Member 1

Sabry, Tarek

Committee Member 2

Shoeib, Tamer

Extent

134 p.

Document Type

Master's Thesis

Rights

The author retains all rights with regard to copyright. The author certifies that written permission from the owner(s) of third-party copyrighted matter included in the thesis, dissertation, paper, or record of study has been obtained. The author further certifies that IRB approval has been obtained for this thesis, or that IRB approval is not necessary for this thesis. Insofar as this thesis, dissertation, paper, or record of study is an educational record as defined in the Family Educational Rights and Privacy Act (FERPA) (20 USC 1232g), the author has granted consent to disclosure of it to anyone who requests a copy.

Institutional Review Board (IRB) Approval

Not necessary for this item

Comments

I would like to express my profound gratitude to both of my advisors; Dr. Salah El-Haggar and Dr. Ahmed El-Gendy for their relentless guidance through the course of my research work and through the process of writing this thesis. My earnest gratitude also has to be extended to Eng. Ahmed, Eng. Mohamed Mostafa, Eng. Mohamed Saeid and Eng. Kasem for their innovative thinking, patience and assistance throughout all stages of the experimental work. Finally, I want to thank my family and friends for their love, unwavering support and encouragement throughout my life, which remained constant through my graduate work. I am eternally grateful for their faith and confidence in me.

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