Biochemical processes by chemoautotrophs such as nitrifiers and sulfide and iron oxidizers are used extensively in wastewater treatment. The research described in this dissertation involved the study of two selected biological processes utilized in wastewater treatment mediated by chemoautotrophic bacteria: nitrification (biological removal of ammonia and nitrogen) and hydrogen sulfide (H2S) re...

Aqueous solutions of amines are often used to remove CO2, H2S and COS from a large number of industrial gas streams. There are several different processes, each suiting a certain application. A recent advance in gas treating technology is the application of sterically hindered amines, which offer capacity advantages for CO2 over commercial amines such as monoethanolamine (MEA) (Sartori and Sava...

A kinetic model for the anaerobic filter (AF) that takes into account the mass fractions of sulfate-reducing bacteria (SRB) (fSRB) and methanogenic bacteria (MB) (fMB) and an inhibiting effect of H2S on bacterial groups is proposed. When the acetate-fed AFs were maintained at the low organic loading rate of 2.5kg COD/m3d, variations of the influent COD/SO4(2-) ratio (0.5-3.0) does not materiall...

Advanced glycation end-products (AGEs) are complex and heterogeneous compounds implicated in diabetes. Sodium reabsorption through the epithelial sodium channel (ENaC) at the distal nephron plays an important role in diabetic hypertension. Here, we report that H2S antagonizes AGEs-induced ENaC activation in A6 cells. ENaC open probability (P O ) in A6 cells was significantly increased by exogen...

A technique is presented that can be used to estimate the changes in physical structure in a natural biofilter packing medium, such as compost, over time. The technique applies information from tracer studies, grain size distribution, and pressure drop analysis to a model that estimates the number of channels, average channel diameter, number of particles, and specific surface area of the mediu...

Lab scale studies were conducted to evaluate the performance of two simultaneously operated immobilized cell biofilters (ICBs) for removing hydrogen sulphide (H2S) and ammonia (NH3) from gas phase. The removal efficiencies (REs) of the biofilter treating H2S varied from 50 to 100% at inlet loading rates (ILRs) varying up to 13 g H2S/m(3) ·h, while the NH3 biofilter showed REs ranging from 60 to...

Magnesium nickel silicate (MNS) has been investigated as a catalyst to convert tars and light hydrocarbons to syngas (CO and H2) by steam reforming and CO2 reforming in the presence of H2S for biomass gasification process at NexTech Materials. It was observed that complete CH4 conversion could be achieved on MNS catalyst granules at 800–900 °C and a space velocity of 24,000 mL/g/h in a simulate...

A mathematical dynamic model describing biological removal of high loads of H2S from biogas streams through a biotrickling filter (BTF) was developed, calibrated and validated to a range of specific experimental conditions of a lab-scale BTF. This model takes into account the main processes occurring in the three phases of the desulfurizing BTF (gas, liquid and biofilm phase) in a co-current co...

Reactive sulfur species have received considerable attention due to their various biological functions. Among these molecules, hydrogen polysulfides (H2S(n), n > 1) are recently suggested to be the actual signaling molecules derived from hydrogen sulfide (H2S). Hydrogen polysulfides may also have their own biosynthetic pathways. The research on H2S(n) is rapidly growing. However, the detection ...

INTRODUCTION Gases, such as nitric oxide (NO), carbon monoxide (CO), or hydrogen sulfide (H2S), termed gasotransmitters, play an increasingly important role in understanding of how electrical signaling of cells is modulated. H2S is well-known to act on various ion channels and receptors. In a previous study we reported that H2S increased calcium-activated potassium (BK) channel activity. AIMS...