Biosorption of lead, copper, cadmium and nickel by anaerobic biomass

This study will introduce anaerobic granules as a novel type of biosorbent for the removal of lead, copper, cadmium, and nickel from aqueous solutions. The work investigated the equilibrium, batch dynamics and continuous column operation for the biosorption process. Binding capacity experiments using viable biomass revealed a higher value than those for nonviable biomass. Binding capacity experiments using non-viable biomass treated with Ca revealed a high value of metals uptake. The solution initial value affected metal sorption. Time dependency experiments for the metal ions uptake showed that adsorption equilibrium was reached almost 30 minutes after metal addition. It was found that the q max for Pb 2+ , Cu 2+ , Cd 2+ and Ni 2+ , were 2.46, 1.74, 1.06 and 0.88 meq/g respectively. The data pertaining to the sorption dependence upon metal ion concentration fitted the Langmiur isotherm model. The kinetics of sorption of Pb 2+ , Cu 2+ , Cd 2+ and Ni 2+ were modelled using a pseudo-second order rate equation. Column adsorption studies were performed for Pb 2+ , Cu 2+ , Cd 2+ , and Ni 2+ . The removal of Pb 2+ , Cu 2+ , Cd 2+ , and Ni 2+ ions from the bed was accompanied by the elution of Ca 2+ ions from the packed-bed. Ion exchange was identified to be the dominant mechanism for the biosorption of nickel by the anaerobic biomass. For copper and cadmium 77% and 82% of the total amount adsorbed was attributed to ion exchange respectively. 18% and 15% of the total amount adsorbed of copper and cadmium was attributed to the extent of a complexation process competing with the ion exchange one respectively. For the case of Pb ions it was found out that ion exchange was attributed to be almost 50% of the total uptake mechanism. 30% of the total uptake mechanism was attributed to precipitation mechanism. The remaining 20% was attributed to a complexation process competing with the ion exchange and precipitation. The affinity order of anaerobic biomass for the four metals under study has been established as: Pb > Cu > Ni > Cd. The selectivity of the biomass for Pb over the other three metals was well exhibited by the results obtained using the flow-through colum

Modeling of the fate of lead due to the removal of corroded sub-marine cables in aquatic environments

The processes by which lead is released from corroded cables and dredged material are complex, but have to be taken into consideration when assessing the potential risk of dredging and removal activities. In this research, the effect of various physical factors on the release and dispersion of lead from corroded sub-marine cables and bottom sediments was studied. Among these factors are the hydrological and physical properties of the water body (e.g. flow rates, resuspension and settling), situation and position of cables (e.g. on the surface or at different depths), physico-chemical characteristics (e.g. adsorption, desorption and diffusion rate), transport of toxicant (e.g. advective and dispersive mixing) and dredging activities (e.g. mechanical and hydraulic). In order to show the effect of different factors, a conceptual model called the Model for Fate of Corroded Lead ( MFCL ) was developed. The objective was to predict lead concentration in the water column in dissolved and particulate forms. The MFCL model is a powerful tool for predicting the changes in risk resulting from the implementation of various remedial actions, including the "no action" alternative

Treatment of Wastewater Using Reverse Osmosis for Irrigation Purposes

This work investigates the performance of reverse osmosis (RO) for the reclamation of treated sewage effluent (TSE) to be used as irrigation water for food crops. The feed water used in this study was a real sample of ultra-filtered tertiary treated sewage effluent (TSE). Reverse osmosis (RO) was evaluated using the following experimental conditions applied pressure (10 - 20) bar, flow rate 3.5 LPM and (BW30LE) membrane. The performance of RO was evaluated according to the water flux and rejection of dissolved solids. The final water quality was compared with irrigation water standards. The results reported in this study show that reverse osmosis (RO) is capable of reclaiming treated sewage effluent (TSE) to be used as irrigation water for food crops. The maximum average flux was 77.7 LMH achieved using a feed pressure of 16 bar. The permeate water generated using RO had high quality which met the irrigation standards for food crops.This research is made possible by graduate sponsorship research award (GSRA6-1- 0509-19021) from Qatar National Research Fund (QNRF). The statements made herein are solely the responsibility of the authors

Impact of Draw Solution Concentration on Forward Osmosis Process: A Simulation Study

In this study, a simulation model was used to evaluate the performance of forward osmosis process. A solution of low salinity was used as the feed solution in forward osmosis to dilute saline solution (i.e. draw solution) for further desalination. The paper evaluated the effect of the draw solution concentration on the recovery rate and energy consumption in forward osmosis. It was found that increasing the concentration of draw solution increased the recovery rate. Also, while increasing concentration of draw solution, energy consumption decreased. The maximum recovery rate of 33% was achieved using (0.5M NaCl) draw solution and a flow rate of 40000 m3/day. The specific power consumption was 0.21 kWh/m3.This research is made possible by Graduate Sponsorship Research Award (GSRA6-1- 0509-19021) from Qatar National Research Fund (QNRF). The statements made herein are solely the responsibility of the authors

Cost benefit analysis for failure of sewer pipelines

Sewer pipelines failure in sewage networks can have adverse potential impacts on socio-economic aspects in any community. Due to the fact that it's difficult to capture the relationship between the physical and economical aspects as a result of critical sewer pipelines failure, economic concepts are used to evaluate the economic loss as a result of these failures. In this paper an analysis for the costs resulting from sewer pipelines failure and the benefits achieved from avoiding failures are presented. The costs included in the cost benefit analysis are the direct costs used to reinstate failed pipelines and the indirect costs, borne by the society and economy. In the benefits analysis, only the tangible and measurable benefits limited to the health sector and preventing diseases are addressed in this paper. It is expected that the proposed approach could help in estimating the economic losses due to sewer pipelines failure especially for the intangible factors that are difficult to measure. In addition it could help decision makers in taking necessary measures to preserve critical assets that could have adverse potential impacts on valuable natural resources such as surface and groundwater and soil surrounding failed pipelines.This publication was made possible by NPRP grant # (NPRP6-357-2-150) from the Qatar National Research Fund (a member of The Qatar Foundation). The statements made herein are solely the responsibility of the authors. Also the authors would like to thank the public works authority of Qatar (ASHGAL) for their support in the data collection.Scopu

Utilizing Steel Slag in the Removal of Suspended Solids from Dewatered Construction Water

Construction dewatering is an operation used to remove shallow groundwater that infiltrates construction sites. After recovering this water from the construction sites, the water is either discharged to the sea, injected in deep groundwater aquifers, or treated and reused in some other applications. However, municipal and industrial application of this water is unfeasible due to its poor quality. Thus, in this study, dewatered construction water is being treated utilizing waste steel slag in order to improve the quality of the water. The pH of the dewatered construction water used for this study was 7.59 and the average diameter of steel slag used was 425 nm. For coagulation, the impact of the mass of steel slag and the contact time on the quality of dewatered construction water were studied. By using 5gm/L of steel slag, more than 85% of the total suspended solids and turbidity were removed within 30 minutes.The authors would like to thank Qatar University for the financial support. In addition, the authors would like to thank Qatar Steel for the supply of the steel slag sample

An enhanced electrocoagulation process for the removal of fe and mn from municipal wastewater using dielectrophoresis (Dep)

In this study the removal of Fe and Mn from primary treated municipal wastewater using a new electrode configuration in electrocoagulation was evaluated. The used electrode configuration induced a dielectrophoretic (DEP) force in the electrocoagulation process. The impact of the electrolysis time, electrodes spacing and applied current on the removal of Fe and Mn was evaluated. The maximum removal percentages of Fe and Mn were obtained using an electrolysis time of 60 min, an electrode spacing of 0.5 cm and an applied current of 800 mA. Under these operating conditions and using the new electrodes configuration, the Fe and Mn removals were 96.8% and 66%, respectively. The main advantage of using the DEP-induced electrode configuration was the minimal consumption of the electrodes. The new electrode configuration showed 42% less aluminum content in the reactor compared to the aluminum electrodes with no DEP effect. The energy consumption at the selected operation conditions was 4.88 kWh/m3. The experimental results were comparable with the simulation results achieved by the COMSOL software. 2021 by the authors. Licensee MDPI, Basel, Switzerland.Acknowledgments: This research was made possible by Awards (GSRA5-2-0525-18072) and (GSRA6-1-0509-19021) from Qatar National Research Fund (a member of Qatar Foundation). The authors would like to thank the Central Laboratories Unit at Qatar University for the measurement of heavy metal. The authors also wish to thank Qatar Works Authority (Ashghal) for the supply of wastewater samples.Scopu

Fouling mitigation strategies for different foulants in membrane distillation

Providing clean water to a rapidly growing population is an issue that is currently getting lots of attention to offer a sustainable solution for water scarcity. Membrane distillation (MD) is one of the latest technologies that provides great potential in water treatment. Even though there is a tremendous amount of research done during the past two decades on membrane distillation, the long-term use of this process is still restricted by membrane fouling. Membrane Fouling can be defined as the accumulation of various materials in the pores or surface of the membrane that affect permeate's quantity and quality. This review highlights the recent observations on various foulants in MD process. Moreover, different fouling mechanisms of inorganic fouling, organic fouling, biological fouling, and colloidal fouling were investigated for better understanding and prevention of membrane fouling. In order to achieve a sustainable MD process, various techniques to mitigate fouling were discussed comprehensively including pre-treatment processes and cleaning methods. The benefits and disadvantages of these approaches have been investigated and reviewed in order to provide an overall understanding of fouling minimization in membrane distillation process. Fouling mitigation strategies have been suggested for different foulants in membrane distillation

Poly (amido amine) dendrimer based membranes for wastewater treatment - A critical review

Membrane based wastewater treatment technologies in which polymeric membranes are most commonly used have been extensively applied in water/wastewater treatment to help address the issue of water shortage through water/wastewater reclamation and reuse. However, polymeric membranes due to their hydrophobic nature are subject damage caused by accumulation of organic/inorganic fouling during filtration processes, which results in a number of issues such as low water flux and low pollutant rejection. Several strategies have been considered to address these challenges and effectively improve the membrane performances. Alteration of membrane properties strategy using suitable nanofillers such us poly (amido amine) or PAMAM has been largely studied. Herein, research efforts regarding the synthesis and properties of PAMAM along with the synthesis of PAMAM multifunctional nanocomposites were concisely reviewed for the first time. Membrane performance enhancement by incorporation of PAMAM were reviewed and discussed. Results and contributions achieved in the improvement of PAMAM incorporated membranes for the treatment of different types of wastewaters has been reviewed and summarized. Furthermore, perspectives on the current challenges and future research needs in the development and application of PAMAM incorporated polymeric membranes to benefit from the potentials that offer these promising new membrane nanofiller were discussed 2023 The Author(s)This research is made possible by graduate sponsorship research award (GSRA7-1-0510-20046) from Qatar National Research Fund (QNRF). The publication of this article was funded by Qatar National Library. The statements made herein are solely the responsibility of the authors Qatar National Library for funding the Open Access Publication.Scopu

A novel electrocoagulation electrode configuration for the removal of total organic carbon from primary treated municipal wastewater

In this paper, the removal of total organic carbon (TOC) from a primary treated municipal wastewater using a new electrode configuration in electrocoagulation was evaluated. The used electrode configuration induces a dielectrophoretic (DEP) force by using an asymmetrical aluminum electrode with an alternating current power supply. The impact of applied current, electrolysis time, and interelectrode distance on the removal efficiency of TOC were evaluated. The experimental results showed that the maximum removal efficiency of TOC was obtained at 30 min electrolysis time, 600 mA applied current, and 0.5 cm interelectrode distance. Under these operating conditions, the TOC removal was 87.7% compared to 80.5% using symmetrical aluminum electrodes with no DEP effect. The energy consumption at the selected operating conditions was 3.92 kWh/m3. The experimental results were comparable with the simulation results done by COMSOL Multiphysics software. 2020, The Author(s).Open Access funding provided by the Qatar National Library. The authors would like to thank Qatar University for the provided financial support. The authors would also like to thank the central Laboratories Unit at Qatar University for TOC analysis. In addition, the authors wish to thank Qatar Foundation for the financial support provided to one of the co-authors through a graduate sponsorship research award (GSRA 6-1-0509-19021).Scopu