Tim Grotenhuis - Academia.edu (original) (raw)

Papers by Tim Grotenhuis

Bioleaching can be one of few techniques applicable for the removal of toxic metals from polluted... more Bioleaching can be one of few techniques applicable for the removal of toxic metals from polluted soils or sediments. Its principle is a microbial production of sulphuric acid and leaching of metals with it. The use of bioleaching can benefit from the use of low-cost substrates and from a ...

While bioremediation of total petroleum hydrocarbons (TPH) is in general a robust technique, hete... more While bioremediation of total petroleum hydrocarbons (TPH) is in general a robust technique, heterogeneity in terms of contaminant and environmental characteristics can impact the extent of biodegradation. The current study investigates the implications of different soil matrix types (anthropogenic fill layer, peat, clay, and sand) and bioavailability on bioremediation of an aged diesel contamination from a heterogeneous site. In addition to an uncontaminated sample for each soil type, samples representing two levels of contamination (high and low) were also used; initial TPH concentrations varied between 1.6 and 26.6 g TPH/kg and bioavailability between 36 and 100 %. While significant biodegradation occurred during 100 days of incubation under biostimulating conditions (64.4-100 % remediation efficiency), low bioavailability restricted full biodegradation, yielding a residual TPH concentration. Respiration levels, as well as the abundance of alkB, encoding mono-oxygenases pivotal for hydrocarbon metabolism, were positively correlated with TPH degradation, demonstrating their usefulness as a proxy for hydrocarbon biodegradation. However, absolute respiration and alkB presence were dependent on soil matrix type, indicating the sensitivity of results to initial environmental conditions. Through investigating biodegradation potential across a heterogeneous site, this research illuminates the interplay between soil matrix type, bioavailability, and bioremediation and the implications of these parameters for the effectiveness of an in situ treatment.

Ecohydrology & Hydrobiology, 2006

ABSTRACT Discharged persistent organic pollutants and heavy metals into the rivers are often assu... more ABSTRACT Discharged persistent organic pollutants and heavy metals into the rivers are often assumed to adsorb on sediments without re-suspension, thus sediments may function as a sink for contaminants. Sediments, however, may also function as a (secondary) source of contaminants, depending on the hydrodynamic characteristics of a river. To assess whether the sediments function as a sink or a source of contaminants, a preliminary risk assessment using the so-called SEDINA tool (SEDiment INitial Assessment) is recommended. By comparison of the total concentrations of pollutants in sediments upstream, at, and downstream of the site area, the role of sediments can be determined. When the sediments functions as a sink, no specific sediments-related measures are required, although monitoring of the surface water and sediments quality is recommended. If the output of the SEDINA tool reflects that the sediments may function or function as a source of contaminants, the risk-reduction measures are necessary that may include emission control at the source(s), pathway(s) and/or receptor(s).

Journal of Hazardous Materials, 2015

Please cite this article as: Eulàlia Martínez-Pascual, Tim Grotenhuis, Anna M underlinea .Solanas... more Please cite this article as: Eulàlia Martínez-Pascual, Tim Grotenhuis, Anna M underlinea .Solanas, Marc Viñas, Coupling chemical oxidation and biostimulation: effects on the natural attenuation capacity and resilience of the native microbial community in alkylbenzene-polluted soil, Journal of Hazardous Materials http://dx.

Contaminated Soil ’95, 1995

The Science of the total environment, 2014

Jinpen Reservoir is a deep, stratified reservoir in Shaanxi province, located in a warm temperate... more Jinpen Reservoir is a deep, stratified reservoir in Shaanxi province, located in a warm temperate zone of Northwest China. Influenced by a temperate monsoon climate, more than 60% of the annual precipitation is concentrated from late summer to autumn (July-September). In recent years, extreme rainfall events occurred more frequently and strongly affected the thermal structure, mixing layer depth and evolution of stratification of Jinpen Reservoir. The reservoir's inflow volume increased sharply after heavy rainfall during the flooding season. Large volumes of inflow induced mixing of stratified water zones in early autumn and disturbed the stratification significantly. A temporary positive effect of such disturbance was the oxygenation of the water close to the bottom of the reservoir, leading to inhibition of the release of nutrients from sediments, especially phosphate. However, the massive inflow induced by storm runoff with increased oxygen-consuming substances led to an inc...

Water research, Jan 15, 2014

Addition of activated carbons (AC) to polluted sediments and soils is an attractive remediation t... more Addition of activated carbons (AC) to polluted sediments and soils is an attractive remediation technique aiming at reducing pore water concentrations of hydrophobic organic contaminants (HOCs). In this study, we present (pseudo-)equilibrium as well as kinetic parameters for sorption of a series of PAHs and PCBs to powdered and granular activated carbons (AC) after three different sediment treatments: sediment mixed with powdered AC (PAC), sediment mixed with granular AC (GAC), and addition of GAC followed by 2 d mixing and subsequent removal ('sediment stripping'). Remediation efficiency was assessed by quantifying fluxes of PAHs towards SPME passive samplers inserted in the sediment top layer, which showed that the efficiency decreased in the order of PAC > GAC stripping > GAC addition. Sorption was very strong to PAC, with Log KAC (L/kg) values up to 10.5. Log KAC values for GAC ranged from 6.3-7.1 and 4.8-6.2 for PAHs and PCBs, respectively. Log KAC values for GAC ...

Applied and environmental microbiology, 1992

The hydrophobicities and electrophoretic mobilities of isolates from methanogenic anaerobic granu... more The hydrophobicities and electrophoretic mobilities of isolates from methanogenic anaerobic granular sludge were measured and compared with those of strains from culture collections. All new isolates were highly hydrophobic, indicating that the upflow anaerobic sludge blanket reactor concept selects for hydrophobic bacteria. Methanothrix soehngenii, a methanogen often observed in methanogenic granular sludge, was highly hydrophobic and showed low electrophoretic mobility at pH 7. The role of this strain in the formation of methanogenic granular sludge is discussed.

Applied and environmental microbiology, 1991

The bacteriological composition and ultrastructure of mesophilic granular methanogenic sludge fro... more The bacteriological composition and ultrastructure of mesophilic granular methanogenic sludge from a large-scale Upflow Anaerobic Sludge Blanket reactor treating wastewater from a sugar plant and of sludge granules adapted to ethanol and propionate were studied by counting different bacterial groups and by immunocytochemical methods. Propionate-grown granular sludge consisted of two types of clusters, those of a rod-shaped bacterium immunologically related to Methanothrix soehngenii and those consisting of two different types of bacteria with a specific spatial orientation. One of these bacteria reacted with antiserum against Methanobrevibacter arboriphilus AZ, whereas the other is most likely a propionate-oxidizing bacterium immunologically unrelated to Syntrophobacter wolinii. Sludge granules obtained from the large-scale Upflow Anaerobic Sludge Blanket reactor and granules cultivated on ethanol did not show the typical spatial orientation of bacteria. Examination of the bacterial...

Journal of Contaminant Hydrology, 2014

Reductive dechlorination of tetrachloroethene (PCE) and its daughter products in aquifers is ofte... more Reductive dechlorination of tetrachloroethene (PCE) and its daughter products in aquifers is often hampered by Fe(III) reducing conditions. Rigorous treatment to adjust the redox potential and stimulate dechlorination may be costly and potentially have negative effects on other aquifer functions. A step-wise experimental strategy was applied to investigate the effectiveness of various adjustment scenarios. Batch experiments with ascorbic acid (AA) and sodium lactate (SL) showed that 75 μmol electron equivalents per gram dry mass of aquifer material was required to reach a sufficiently low redox potential for the onset of PCE dechlorination. Similar effects of either AA or SL on the measured redox potential suggest electron donors are not specific. However, the relative rates of Fe(III) and sulphate reduction appeared to be specific to the electron donor applied. While redox potential stabilised around −450 mV after titration and sulphate was reduced to zero in both treatments, in the AA treatment a faster production of Fe 2+ was observed with a final concentration of 0.46 mM compared to only 0.07 mM in the SL treatment. In subsequent batch experiments with aquifer material that was pre-treated with AA or SL, PCE reductive dechlorination occurred within 30 days. Further stimulation tests with extra electron donor or inoculum revealed that adding electron donor can accelerate the initiation of PCE biodegradation. However, bioaugmentation with dechlorinating bacteria is required to achieve complete reductive dechlorination to ethene. The findings from step-wise approaches are relevant for improving the cost-effectiveness of the design and operation of in-situ bioremediation at initially unfavourable environmental conditions.