Impact of soluble organic matter and particulate organic matter on anammox system: Performance,microbial community and N2O production

In this study,the effects of soluble readily biodegradable COD (sCOD) and particulate slowly biodegradable COD (pCOD) on anammox process were investigated.The results of the longterm experiment indicated that a low sCOD/N ratio of 0.5 could accelerate the anammox and denitrification activity,to reach as high as 84.9%±2.8% TN removal efficiency.Partial denitrification-anammox (PDN/anammox) and denitrification were proposed as the major pathways for nitrogen removal,accounting for 91.3% and 8.7% o...     

Betaine removal during thermo- and mesophilic aerobic batch biodegradation of beet molasses vinasse: influence of temperature and pH on the progress and efficiency of the process

The key issue in achieving a high extent of biodegradation of beet molasses vinasse is to establish the conditions for the assimilation of betaine, which is the main pollutant in this high-strength industrial effluent. In the present study, aerobic batch biodegradation was conducted over the temperature range of 27-63°C (step 9°C), at a pH of 6.5 and 8.0, using a mixed culture of bacteria of the genus Bacillus. Betaine was assimilated at 27-54°C and the pH of 8.0, as well as at 27-45°C and the pH of 6.5. The processes where betaine was assimilated produced a high BOD(5) removal, which exceeded 99.40% over the temperature range of 27-45°C at the pH of 8.0, as well as at 27°C and the pH of 6.5. Maximal COD removal (88.73%) was attained at 36°C and the pH of 6.5. The results indicate that the process can be applied on an industrial scale as the first step in the treatment of beet molasses vinasse.     

Distribution of volatile organohalogen compounds in petrochemical plant water streams

The study assesses halogenated volatile organic compound concentrations in the water and wastewater streams of a petrochemical plant. Water samples were collected at 11 sampling points during 5 sampling campaigns. The samples were collected from the oil dewaxing unit and in the wastewater treatment plant. Dichloromethane and 1,2-dichloroethane were the most frequently determined compounds. Tetrachloroethene was also detected at the wastewater treatment plant inlets. The concentrations of halogenated volatile organic compounds dropped significantly at wastewater discharge points compared to wastewater treatment plant inlets. The application of 1,2-dichloroethane/dichloromethane ratio as a tool to assess evaporation processes is discussed.     

A new derivatization method for a determination of MX and related hydroxyfuranones in water

An extremely potent mutagen, 3‐chloro‐4(dichloromethyl)‐5‐hydroxy‐2(5/f)‐furanone (MX) is commonly present in chlorinated drinking water. Due to its high mutagenic activity and according to WHO guidelines its concentration should be controlled in drinking waters. Determination of MX is difficult due to ppt levels at which the compound usually exists in drinking waters. Derivatization with 2‐propanol is presented as a method which significantly lowers GC/MS detection level of MX. Suitability of 2‐propylation for derivatization of other hydroxyfuranones is also shown.     

Changes in concentration levels of selected VOCs in newly erected and remodelled building in Gdansk

Volatile organic compounds such as benzene, toluene, butyl acetate, ethylbenzene, m-xylene, styrene and m-dichlorobenzene were measured in three newly erected and remodelled dwellings. The present study also attempted to examine the time dependence of concentrations of selected VOCs in each investigated dwelling. This was accomplished by at least triplicate measurements of the IAQ. To collect a series of air samples the active and passive methods were used. In both cases activated charcoal was applied as a sorption medium. The samples were recovered by solvent extraction, and analysed by capillary column gas chromatography, employing a flame ionisation detector. The experimental results showed that MAC values for analysed VOCs were exceeded (even a few orders of magnitude) for the measurements made before inhabiting of the occupants, in every investigated dwelling. The concentrations of the investigated VOCs decreased significantly with time, which should be expected, although in some cases the levels of selected VOCs remained still high. Our experience indicates that parallel application of two different indoor air sampling techniques to determine analytes of interest, though more laborious and time consuming, can lead to significant conclusions concerning indoor air quality in monitored spaces.     

Effects of cadmium and zinc on larval growth and survival in the ground beetle,Pterostichus oblongopunctatus

Carabid beetles, like Pterostichus oblongopunctatus, living in metal contaminated areas may be exposed to elevated levels of metals within their diets. However, when compared to other second order consumers, they have one of the lowest observed levels of metals, indicating methods of detoxification to deal with such toxicants. In this study, we investigated if chronic, multigenerational exposure to metals leads to resistance to toxic metal concentrations, and if so, what are the costs associated with them. Adult organisms were collected from two sites, a polluted and a reference site near Olkusz, in southern Poland. These adults were immediately mated, and eggs were collected twice weekly to assess the effects in the larvae of the F(1) generation. Larvae were randomly exposed to one of four artificial mediums: control, 50 mg kg(-1) Cd, 500 mg kg(-1) Zn, and a combined treatment of 50 mg kg(-1) Cd and 500 mg kg(-1) Zn to investigate possible interactions. Individuals were sacrificed at 10, 30, and 40 days. Although metals were not accumulated in larvae (p>0.05), larvae fed the Cd or the Zn treatment grew significantly slower, and had the lowest survival rate (p<0.05) in respect to control. Out of metal treated animals, those on the combined treatment of CdZn grew the quickest and had the highest observed survival (p<0.05). Although previous studies have demonstrated changes in adult population parameters under chronic, multigeneration exposure to toxic metal concentrations, our study did not reveal any changes in the larval stage.     

Chromium occurrence in the environment and methods of its speciation

This article includes a survey of chromium (Cr) occurrence in different environmental compartments, its pathways in the environment and the cross-sectional presentation of Cr speciation methods against the background of Cr chemistry. The aim of the article is to demonstrate that knowledge of interconversion processes between different Cr forms is necessary to understand its behaviour and role in the environment, in addition to enabling reliable Cr speciation analysis to be performed. The current methods of Cr speciation are presented, characterized and their usefulness discussed. These must rely on superior separation and detection capabilities since Cr in environmental compartments is mostly at trace or ultra-trace level. The need for using unique techniques of sampling, storage, handling and separation for Cr speciation is documented.     

Constrained Laboratory vs. Unconstrained Steering-Induced Rollover Crash Tests

Objective: The goal of this study was to evaluate how well an in-laboratory rollover crash test methodology that constrains vehicle motion can reproduce the dynamics of unconstrained full-scale steering-induced rollover crash tests in sand.

Methods: Data from previously-published unconstrained steering-induced rollover crash tests using a full-size pickup and mid-sized sedan were analyzed to determine vehicle-to-ground impact conditions and kinematic response of the vehicles throughout the tests. Then, a pair of replicate vehicles were prepared to match the inertial properties of the steering-induced test vehicles and configured to record dynamic roof structure deformations and kinematic response.

Results: Both vehicles experienced greater increases in roll-axis angular velocities in the unconstrained tests than in the constrained tests; however, the increases that occurred during the trailing side roof interaction were nearly identical between tests for both vehicles. Both vehicles experienced linear accelerations in the constrained tests that were similar to those in the unconstrained tests, but the pickup, in particular, had accelerations that were matched in magnitude, timing, and duration very closely between the two test types. Deformations in the truck test were higher in the constrained than the unconstrained, and deformations in the sedan were greater in the unconstrained than the constrained as a result of constraints of the test fixture, and differences in impact velocity for the trailing side.

Conclusions: The results of the current study suggest that in-laboratory rollover tests can be used to simulate the injury-causing portions of unconstrained rollover crashes. To date, such a demonstration has not yet been published in the open literature. This study did, however, show that road surface can affect vehicle response in a way that may not be able to be mimicked in the laboratory. Lastly, this study showed that configuring the in-laboratory tests to match the leading-side touchdown conditions could result in differences in the trailing side impact conditions.