Recent advances in molecular biology have extended our understanding of the metabolic processes related to microbial transformation of petroleum hydrocarbons. The physiological responses of microorganisms to the presence of hydrocarbons, including cell surface alterations and adaptive mechanisms for uptake and efflux of these substrates, have been characterized. New molecular techniques have enhanced our ability to investigate the dynamics of microbial communities in petroleum-impacted ecosystems. By establishing conditions which maximize rates and extents of microbial growth, hydrocarbon access, and transformation, highly accelerated and bioreactor-based petroleum waste degradation processes have been implemented. Biofilters capable of removing and biodegrading volatile petroleum contaminants in air streams with short substrate-microbe contact times ( 2 S and sulfoxides from petrochemical waste streams. Microbes also have potential for use in removal of nitrogen from crude oil leading to reduced nitric oxide emissions provided that technical problems similar to those experienced in biodesulfurization can be solved. Enzymes are being exploited to produce added-value products from petroleum substrates, and bacterial biosensors are being used to analyze petroleum-contaminated environments.

Recent Advances in Petroleum Microbiology

New ecolabels for textile products and tighter restrictions on waste- water discharges are forcing textile wet processors to reuse process water and chemicals. This challenge has prompted intensive research in new advanced treatment technologies, some of which currently making their way to full-scale installations. These comprise polishing treatments such as -ltration, chemical oxidation and specialized Nocculation techniques and pre-treatment steps includ- ing anaerobic digestion, -xed--lm bioreactors, FentonIs reagent oxidation, elec- trolysis, or foam Notation. Though several of these new technologies are promising in terms of cost and performance, they all su†er limitations which require further research and/or need broader validation. A segment of the research deals with the separate handling of speci-c sub-streams such as dyebath effluents to which membrane -ltration is sometimes applied. The main limitation of this approach is the treatment of the concentrate stream. The spectrum of available technologies may, in the future, be further broadened to include oxidation, specialized bio-sorptive processes, solvent extrac- fungi/H 2 O 2 -driven tion, or photocatalysis. 1998 SCI ( J. Chem. T echnol. Biotechnol. 72, 289E302 (1998)

Treatment and Reuse of Wastewater from the Textile Wet-Processing Industry : Review of Emerging Technologies

Ammonia inhibition in anaerobic digestion: A review

A critical review on inhibition of anaerobic digestion process by excess ammonia.

Seawater desalination using renewable energy sources

The role of indigenous microorganisms in suppression of Salmonella regrowth in composted biosolids.

Regrowth of faecal coliforms and salmonellae in stored biosolids and soil amended with biosolids

Mitigating ammonia inhibition of thermophilic anaerobic treatment of digested piggery wastewater: Use of pH reduction, zeolite, biomass and humic acid

In analogy to the well established dependency of microbial reactions on the redox potential of the terminal electron acceptor, the dependency of the microbial activity in a highly active microbial fuel cell on the potential of the electron-accepting electrode (anode) in a microbial fuel cell (MFC) is investigated. An acetate-fed, pH-controlled MFC was operated for over 200 days to establish a highly active MFC anodic biofilm using ferricyanide as the catholyte and granular graphite as electrode material. From the Coulombic efficiency of 83% of the MFC the microbial activity could be recorded by online monitoring of the current. Our results suggest that (1) in analogy to the Michaelis–Menten kinetics a half-saturation anodic potential (here termed kAP value) could be established at which the microbial metabolic rate reached half its maximum rate. This kAP value was about −455 mV (vs Ag/AgCl) for our acetate-driven MFC and independent of the oxidation capacity of the cathodic half-cell; (2) a critical AP (h...

Affinity of microbial fuel cell biofilm for the anodic potential.

Considering water-energy nexus in optimising water supply systems not only ensures the sustainability of the water supply for increasing water demand but also diminishes water-related energy and environmental concerns. This paper presents a review highlighting knowledge gaps in optimisation models related to the water-energy nexus in water supply systems or “water supply side of the nexus”. Studies reported in the literature are categorised and systematically analysed in terms of different energy sources, centralised/ decentralised approaches and system parameters uncertainties. Several major gaps are identified. These include the lack of optimisation models capturing spatial aspects as well as environmental impacts of the nexus problems. The shortage of models considering uncertainties associated with water demand and renewable energy supply is another knowledge gap in this area. However, the main gap is the absence of models for optimising long-term planning of water supply system considering renewable energy within an urban context. Accordingly, based on this review, we have suggested pointers for future studies in the water supply side of the nexus.

Goen Ho

Papers

The role of indigenous microorganisms in suppression of Salmonella regrowth in composted biosolids.

Regrowth of faecal coliforms and salmonellae in stored biosolids and soil amended with biosolids

Mitigating ammonia inhibition of thermophilic anaerobic treatment of digested piggery wastewater: Use of pH reduction, zeolite, biomass and humic acid

Affinity of microbial fuel cell biofilm for the anodic potential.

The role of water-energy nexus in optimising water supply systems – Review of techniques and approaches