Skip to main content
main-content

Über dieses Buch

The most commonly used biological wastewater treatment technologies still have serious technical-economical and sustainability-related limitations, due to their high energy requirements, poor effluent quality, and lack of energy and resource recovery processes. In this thesis, novel electrochemical membrane bioreactors (EMBRs), which take advantage of membrane separation and bioelectrochemical techniques, are developed for wastewater treatment and the simultaneous recovery of energy and resources. Above all, this innovative system holds great promise for the efficient wastewater treatment and energy recovery. It can potentially recover net energy from wastewater while at the same time harvesting high-quality effluent. The book also provides a proof-of-concept study showing that electrochemical control might offer a promising in-situ means of suppressing membrane fouling. Lastly, by integrating electrodialysis into EMBRs, phosphate separation and recovery are achieved. Hence, these new EMBR techniques provide viable alternatives for sustainable wastewater treatment and resource recovery.

Inhaltsverzeichnis

Frontmatter

Chapter 1. Introduction

Abstract
Environmental pollution and water, food, as well as energy shortage are the major issues facing the world today (McCarty et al. in Environ Sci Technol 45:7100–7106, 2011 [5]; Vorosmarty et al. in Nature 467:555–561, 2010 [9]). The over-exploitation and irrational use of resources by human beings has leaded to the current energy and resource crisis, and also caused adverse effects on the environment. Water pollution and the resulting shortage of water resources also seriously threaten human health and social development.
Yunkun Wang

Chapter 2. Research Background and Literature Review

Abstract
MBR is a wastewater treatment equipment that combining membrane filtration process and activated sludge technology. Owning to its compact structure, high treatment efficiency and excellent effluent quality, MBR is widely used in urban sewage and industrial wastewater treatment.
Yunkun Wang

Chapter 3. Intermittently Aerated MBR for Nutrients Removal and Phosphorus Recovery

Abstract
Recovering nutrients, especially phosphate resource, from wastewater have attracted increasing interest recently. Herein, an intermittently aerated membrane bioreactor with a mesh filter was developed for simultaneous organics, nitrogen and phosphorous removal, followed by phosphorus recovery from the phosphorus-rich sludge. This integrated system showed enhanced performances in nitrification and denitrification and phosphorous removal without excess sludge discharged. The removal of chemical oxygen demand, total nitrogen and total phosphorus in a modified membrane bioreactor were averaged at 94.4 ± 2.5%, 94.2 ± 5.7% and 53.3 ± 29.7%, respectively. The removed TP was stored in biomass, and 68.7% of the stored phosphorous in the sludge could be recovered as concentrated phosphate solution with a concentration of phosphate above 350 mg/L. The sludge after phosphorus release could be returned back to the MBR for phosphorus uptake, and 83.8% of its capacity could be recovered.
Yunkun Wang

Chapter 4. Development of an Energy-Saving Anaerobic Hybrid Membrane Bioreactors for 2-Chlorophenol-Contained Wastewater Treatment

Abstract
A novel energy-saving anaerobic hybrid membrane bioreactor (AnHMBR) with mesh filter, which takes advantage of anaerobic membrane bioreactor and fixed-bed biofilm reactor, is developed for chlorophenol-contained wastewater treatment. In this system, the anaerobic membrane bioreactor is stuffed with granular activated carbon to construct an anaerobic hybrid fixed-bed biofilm membrane bioreactor for the low-strength 2-chlorophenol (2-CP)-contained wastewater treatment. The effluent turbidity from the AnHMBR system was low during most of the operation period, and the chemical oxygen demand and 2-CP removal efficiencies averaged 82.3% and 92.6%, respectively. A low membrane fouling rate (4.6 × 10m−1 h−1) of the AnHMBR was obtained under the low biomass concentration and relative low membrane flux. During the AnHMBR operation, the only energy consumption was for feed pump. And a low energy demand of 0.0045–0.0063 kWh m−3 was estimated under the current operation conditions. All these results demonstrated that this novel AnHMBR is a sustainable technology for treating 2-CP-contained wastewater.
Yunkun Wang

Chapter 5. Development of Electrochemical Membrane Bioreactor Technologies for Sustainable Wastewater Treatment

Abstract
One possible way to address both water and energy shortage issues, the two of major global challenges, is to recover energy and water resource from wastewater. Herein, novel electrochemical membrane bioreactors EMBRs, which take advantage of a membrane bioreactor and microbial fuel cells, were developed to recover energy from wastewater and meantime harvest clean water for reuse. With the help of the microorganisms in the biocatalysis and biodegradation process, net electricity could be recovered from a low-strength synthetic wastewater after estimating total energy consumption of this system. In addition, high-quality clean water was obtained for reuse. The results clearly demonstrate that, under the optimized operating conditions, it is possible to recover net energy from wastewater, while at the same time to harvest high-quality effluent for reuse with this novel wastewater treatment system.
Yunkun Wang

Chapter 6. In Situ Utilization of Generated Electricity in an Electrochemical Membrane Bioreactor to Mitigate Membrane Fouling

Abstract
How to mitigate membrane fouling remains a critical challenge for widespread application of membrane bioreactors. Herein, an antifouling electrochemical membrane bioreactor (EMBR) was developed based on in situ utilization of the generated electricity for fouling control. In this system, a maximum power density of 1.43 W/m3 and a current density of 18.49 A/m3 were obtained. The results demonstrate that the formed electric field reduced the deposition of sludge on membrane surface by enhancing the electrostatic repulsive force between them. The produced H2O2 at the cathode also contributed to the fouling mitigation by in situ removing the membrane foulants. In addition, 93.7% chemical oxygen demand (COD) removal and 96.5% NH4+–N removal in average as well as a low effluent turbidity of below 2 NTU were achieved, indicating a good wastewater treatment performance of the EMBR. This work provides a proof-of-concept study of an antifouling MBR with high wastewater treatment efficiency and electricity recovery, and implies that electrochemical control might provide another promising avenue to in situ suppress the membrane fouling in MBRs.
Yunkun Wang

Chapter 7. In Situ Utilization of Generated Electricity for Nutrient Recovery in Urine Treatment Using a Selective Electrodialysis Membrane Bioreactor

Abstract
Recovering resources, especially energy and nutrients, from source-separated urine, is attracting increasing interest. By integrating electrodialysis into an electrochemical membrane bioreactor, a novel, selectively electrodialysis membrane bioreactor (EDMBR) was developed for the treatment of source-separated urine and nutrient recovery. Before injection into the EDMBR system, the diluted urine was pretreated by ammonia stripping. The concentration of ammonia in the urine decreased from 1292.2 ± 47.5 to 235.1 ± 5.7 mg/L upon stripping, denoting an 81.8% ammonia removal efficiency. Phosphate and sulfate recovery from urine were then achieved in situ, utilizing the electricity generated by selective electrodialysis in the EDMBR. In this EDMBR system, which was fed with treated urine after stripping, a maximum power density of 23.5 W/m3 was obtained at an external resistance of 1000 Ω. Consequently, 97.4% of the NH4+, 76.7% of the PO43−, and 94.5% of the SO42− was removed, while 65% of the phosphate and 54.9% of the sulfate (based on their amounts in urine after stripping) were recovered as a concentrated solution. Moreover, other salts, especially NaCl, were selectively retained as brine, indicating that the EDMBR shows promise for urine desalination. This study demonstrates a new strategy for nutrient separation and recovery from source-separated urine by utilizing bioelectricity generated in situ.
Yunkun Wang

Backmatter

Weitere Informationen