Eyal Kurzbaum

Combined chemical-biological treatment for prevention/rehabilitation of clogged wells by an iron-oxidizing bacterium.

Groundwater wells containing large concentrations of ferrous iron face serious clogging problems as a result of biotic iron oxidation. Following a short time after their start off, wells get clogged, and their production efficiency drop significantly up to a total obstruction, making cleanup and rehabilitation an economic burden. The present study was undertaken to test an experimental combined treatment (chemical and biological) for future prevention or rehabilitation of clogged wells. Sphaerotilus natans (an iron-oxidizing bacterium) freshly isolated from a deep well was grown to form biofilms on two systems: coupons and sand buried miniature wedge wire screen baskets. A combined chemical-biological treatment, applied at laboratory scale by use of glycolic acid (2%) and isolated bacteriophages against Sphaerotilus natans (SN1 and ER1-a newly isolated phage) at low multiplicity of infection (MOI), showed inhibition of biofilm formation and inactivation of the contaminant bacteria. In addition to complete inactivation of S. natans planktonic bacteria by the respective phages, earlier biofilm treatment with reduced glycolic acid concentration revealed efficient exopolysaccharide (EPS) digestion allowing phages to be increasingly efficient against biofilm matrix bacteria. Utilization of this combined treatment revealed clean surfaces of a model stainless steel wedge wire screen baskets (commonly used in wells) for up to 60 days.

Small-bioreactor platform technology as a municipal wastewater additive treatment

The bioaugmentation treatment approach presents both an economical and environmentally friendly solution for wastewater treatment. However, the use of exogenous bacterial cultures presents several limitations: negative interaction between microorganisms and adaptation to new physical and chemical composite environment. These selective forces create a significant challenge for the introduced culture to achieving the required biomass in order to conduct the target biological treatment. Small-bioreactor platform (SBP) technology is aimed at introducing exogenous bacterial culture with some protection to reduce some of the natural selection process. The current study was aimed at validating the use of SBP technology to improve biological treatment, especially during a stress period, by using macro-encapsulated bioaugmentation treatment. The study results indicate that the use of SBP technology elevates the stability of biological treatment, improving operational factors such as the reduction of foaming phenomena and sludge accumulation. Still, a significant study needs to be conducted to understand the potential of this technology; especially the impact on biological treatment by using different types of microorganisms for different types of wastewaters and the relationship between the biomass within the SBP capsules and the natural microorganisms.

Improvement of water quality using constructed wetland systems.

Abstract Constructed wetlands are among the recently proven efficient technologies for wastewater treatment. Compared with conventional treatment systems, constructed wetlands are low in cost, easily operated and maintained, and have a strong potential for application in developing countries, particularly by small rural communities. Nevertheless, the use of constructed wetlands for the improvement of drinking water quality (such as the purification of river water for drinking purposes) is still uncommon. Treatment technologies that use natural processes and/or passive components continue to be of interest to many segments of society for a wide variety of applications. This article summarizes information on the current methods used for water treatment using constructed wetland systems and presents several case studies.

A novel bioaugmentation treatment approach using a confined microbial environment: a case study in a Membrane Bioreactor wastewater treatment plant

ABSTRACT A novel bioaugmentation treatment approach, the Small-Bioreactor Platform (SBP) technology, was developed to increase the biological stabilization process in the treatment of wastewater in order to improve wastewater processing effectiveness. The SBP microfiltration membrane provides protection against the natural selection forces that target exogenous bacterial cultures within wastewater. As a result, the exogenous microorganisms culture adapt and proliferate, thus providing a successful bioaugmentation process in wastewater treatment. The new bioaugmentation treatment approach was studied in a full configuration Membrane Bioreactor (MBR) plant treating domestic wastewater. Our results present the potential of this innovative technology to eliminate, or reduce, the intensity of stress events, as well as shortening the recovery time after stress events, consequently elevating the treatment effectiveness. The effective dose of SBP capsules per cubic metre per day of wastewater was achieved during the addition of 3000 SBP capsules (1.25 SBP capsules per cubic metre per day), which provided approximately 4.5 L of high concentration exogenous biomass culture within the SBP capsules internal medium. This study demonstrates an innovative treatment capability which provides an effective bioaugmentation treatment in an MBR domestic wastewater treatment plant.

Aspects of carbon dioxide mitigation in a closed microalgae photo-bioreactor supplied with flue gas

The aim of the present study is to investigate the potential of flue gases to be efficiently and economically applied in production of algal biomass in a photobioreactor (PBR). Various microalgae strains (Chlorella sorokiniana 211-234, Bracteacoccus minor 61.80, Radiosphaera negevensis 87.80, Chlorosarcinopsis negevensis 67.80 and Chlorococcum novae-angliae 5.85) had been tested for CO2 mitigation, growth and tolerance to high CO2 levels. The flue gas and CO2 bubbling induced a significant algal mass growth compared to control (ambient air). Removal of CO2 and NO by the studied microalgae strains was found to be 44% and 33% along daily intervals, respectively. A growth rate of ~0.4g L−1 d−1 was obtained for all algal species tested. Growth conditions for tested algae can be optimised through PBR technology in order to obtain highest biomass yield for production of valuable biochemicals (i.e., low-cost biofuel).

Facilitated enumeration of the silicate bacterium Paenibacillus mucilaginosus comb. nov. (formerly Bacillus mucilaginosus) via tetrazolium chloride incorporation into a double agar-based solid growth medium

Accurate enumeration of Paenibacillus mucilaginosus (formerly Bacillus mucilaginosus) bacterium from environmental samples on solid medium is challenging owing to its extensive extracellular polysaccharides (EPS) excretion. In the present study, P. mucilaginosus enumeration has been facilitated by a simple modification: addition of triphenyl tetrazolium chloride (TTC) to growth medium and application of a second soft agar layer. Results show distinctively better and accurate colonies’ count. This method can be applied to all bacterial species that produce excessive EPS that may interfere with direct count.