Bacterial antibiotic resistance has long been a public health concern worldwide. Although antibiotic abuse highly correlates with occurrence of resistant pathogens in hot spots like animal feedlots, it remains obscure how frequently these resistance genotypes would emerge and/or retain in natural circumstances. In this study, we monitored seven antibiotic resistance genes in various surface waters. All seven resistance genes were detectable in Puzih River samples, including strA (40.6 %), cmlA (29.7 %), blaTEM (9.1 %), tet(B) (8.5 %), sul1 (7.9 %), mecA (3.6 %), and tet(A) (2.4 %). Among these genes, strA was observed in four out of five sampling occasions during the 1.5-year monitoring period and most of the genes were detected at least two times over five samplings. These results imply that surface waters in Taiwan act as potential reservoirs for several resistance genotypes. Moreover, high prevalence of tet(A) (92.0 %) and sul1 (96.0 %) in swine farm wastewater samples suggests routine antibiotic usage and particularly, the fodder supplements could indeed be a risk factor to antibiotic resistance in environments. sul1, tet(A), blaTEM, and strA were detectable in domestic water treatment plants and reservoirs, suggesting that several resistance genotypes against antibiotics as streptomycin, ampicillin, tetracycline, and sulfonamides are likely to persist in natural circumstance and may consequently contaminate the drinking water systems.

The study provided a critical appraisal of the extended aeration process as a single-sludge system for nitrogen removal, emphasizing its inherent deficiencies. For this purpose, the system was designed first using the prescribed procedure in the German practice, ATV A-131. The design used the basic data reported in different studies related to conventional characterization and chemical oxygen demand (COD) fractionation defining the biodegradation characteristics of domestic wastewater. A critical appraisal of the design was made with emphasis on the fate of biodegradable COD and oxidized nitrogen in the anoxic phase by process modeling and evaluation. The results obtained were evaluated using basic stoichiometry and mass balance for major nitrogen fractions. The A-131 design based on a total sludge age of 20 days defined a system with a hydraulic residence time of 1.2 days where half of the volume was operated under anoxic conditions; the effluent nitrate concentration was reduced to 8.3 mg N/L with an internal recycle (nitrate) ratio of 4.9. Model evaluation of the prescribed design indicated that oxidized nitrogen was totally consumed within the first 25–30 % portion of the anoxic volume. The remaining volume was forced to operate under anaerobic conditions, where no appreciable endogenous decay would occur. ATV A-131 procedure, relying on empirical coefficients and expressions, was neither consistent with process stoichiometry nor justifiable by modeling. Evaluations based on modeling and process stoichiometry revealed significant inherent weaknesses of extended aeration for providing a sustainable basis for nitrogen removal.

Acidic deposition is a worldwide problem that often leads to the increase in soil available heavy metals. Liming and biochar can both raise soil pH and immobilize heavy metals. An experiment was conducted in the laboratory to study the effects of acidic deposition on soil Cd mobility and soil biological activity in a soil polluted with Cd. Biochar, prepared from poultry litter biochar (PLB) or eucalyptus biochar (EB) was added at a rate of 3 %. Liming controls, bringing the soil to the same pH as that attained with biochar, were also used. The experimental results showed a higher risk of Cd leaching and impaired biological properties under simulated acid rain. Biochar addition resulted in a reduction in the risk of leaching and in improved biological properties and could provide benefits over liming for the management of soil polluted with heavy metals, especially in areas affected by acidic deposition.

The aim of this study is to use a range of statistical tools to assess particulate matter less than 10 μm (PM₁₀) in the atmosphere that has been measured daily at five locations in South Australia over a 7-year period. We consider a wind rose model to provide a graphical display of the frequency distribution of wind speed to explore the role of PM₁₀ accumulation over time. A generalised least squares technique with a first-order autoregressive model was applied to the realisation of average changes in PM₁₀, and these were assessed at the 5 % significance level. This study found the change in variability of PM₁₀ concentration over time. The pre-whitened PM₁₀ series were considered as realisations of white noise using correlogram plots. Furthermore, a robust regression technique involving wet (>0.5-mm rainfall) and dry properties (<0.5-mm rainfall) was used to assess the influence of rainfall on PM₁₀ distributions for the city of Adelaide.

The aim of the study was to estimate the influence of soil pH on the uptake of copper, zinc, and manganese by Valeriana officinalis. Preliminary studies involved soil analyses to determine acidity, organic matter content, and copper, zinc, and manganese total and bioavailable forms. The study involved atomic absorption spectrometry to determine the concentration of the elements, and mineral soil of pH = 5.1 was used in the study, as being typical for central Poland. The copper, zinc, and manganese contents were determined in plants grown in soils which had been modified to cover a wide range of pH values 3÷13. The intensity of germination was strongly pH dependent with the highest yield obtained in original, unmodified soil. Surprisingly, high soil alkalinity stimulated copper and manganese uptake while at the same time resulting in a decrease in zinc content.

In this work, we developed a method based on ultrasound-assisted emulsification microextraction (USAEME) for the determination of nickel by flame atomic absorption spectrometry (FAAS). The method is based on the use of the organic solvent trichloroethylene and 2,2′-thiazolylazo-p-cresol (TAC) as a chelating reagent in a solution containing nickel ions. After ultrasonic emulsification, the mixture is centrifuged to separate the phases. Subsequently, the supernatant is discarded, and the enriched phase is diluted with nitric acid. The nickel content in this new mixture is quantified by FAAS. The following variables were optimized: type of solvent (trichloroethylene), type of chelating reagent (TAC), volume of extraction solvent (100 mL), concentration of chelating reagent (0.015 % w/v), pH (8.0), time of sonication (5.0 min), and time of centrifugation (4.0 min). The limits of detection and quantification were calculated under optimum conditions (0.23 and 0.77 μg L⁻¹, respectively). The enrichment factor obtained was 190. The relative standard deviation (RSD%) of the method (10.0 μg L⁻¹) was 2.3–4.1 %. The proposed method is simple, economical, fast, and efficient for the determination of nickel by FAAS. The procedure was applied to the determination of nickel in certified reference material (BCR-713, wastewater) and water samples.

Road dust organic matter plays a vital role in mobilization of contaminants. This study investigated and characterized organic matter (OM) presents in road dust particles of various sizes. Road dust samples were collected from an industrialized city of Ulsan, Republic of Korea and fractionated into four groups: <75, 75–180, 180–850, and 850–2000 μm. OM extracted from the four fractions was characterized by excitation-emission matrix fluorescence and analyzed by parallel factor analysis (PARAFAC). The PARAFAC identified four major fluorophore components (C1–C4). These components were related to microbial humic-like, anthropogenic organic, fulvic-like, and low molecular weight OM contributed by anthropogenic activity, respectively. There were subtle changes in specific OM composition with change in particle size. The finest fraction contained more microbial humic-like substances whereas the coarse fraction was enriched with fulvic acid. The OM in two fractions (75–180 and 180–800 μm) showed dual characteristics. Our findings demonstrated that PARAFAC approach can assist to assess the accumulation of pollutants in road dust.

The phenolics and high organic content present in palm oil mill effluent are the major contributors to its dark brown color, toxicity, and antimicrobial properties. In this study, ten white rot fungi were screened for their potential in the dephenolization and decolorization of treated palm oil mill effluent (TPOME) in solid and liquid state cultures. Among them, Trametes hirsuta strain AK 04 was found to be more tolerant to high TPOME concentrations and showed the highest phenolics and color removal activities. This strain was immobilized onto oil palm fibers (OPFs) and appeared more resistant to inhibitory compounds such as phenolics in TPOME than the free cell culture. The OPF-immobilized fungus was able to effectively remove phenolics and color of TPOME without effluent dilution and addition of nutrients. The activities of laccase and manganese peroxidase were found during dephenolization and decolorization processes. Moreover, the degradation rate of immobilized fungus could be accelerated by pretreatment of phenolics with phenol-degrading bacteria. This method improved the fungal dephenolization and decolorization simultaneously up to 82.2 ± 3.8 % and 87.1 ± 1.1 % after 8 days of incubation. Therefore, a two-stage biological process containing phenol-degrading bacteria and OPF-immobilized fungus could be a feasible and economical method for simultaneous improvement of dephenolization and decolorization of TPOME.

This study examined a single underground coal mine and investigated two aspects of its operation: the disposal of the mine waste through a discharge to a nearby river and the impact of subsidence from an underground longwall to a small waterway above. Water quality of the two waterways was monitored over a 2-year period with a monthly investigation over a 6-month period, which included collection of stream macroinvertebrates. Both mine activities modified surface water geochemistry and macroinvertebrate communities. Mean electrical conductivity (EC) increased in surface waters below the mine discharge, rising 4.8 times from (186 μS/cm) upstream to 1078 μS/cm below the waste inflow. Mean EC increased in a small stream that was disturbed by subsidence from longwall mining, rising 3.8 times from (247 μS/cm) upstream to 1195 μS/cm below. The mineral constituents of the increased salinities were different. The coal mine wastewater discharge was enriched with sodium and bicarbonate ions compared to sodium and chloride ions in the subsidence affected creek. Both the waste discharge and the subsidence caused increases in the concentrations of zinc by about four times and nickel by 20 to 30 times the background levels. The subsidence reduced dissolved oxygen to ecologically stressful levels and increased iron and manganese concentrations by about 20 times the background levels. Two of the key changes in stream ecosystems were a reduction in the proportion of mayfly larvae downstream of the mine waste discharge and mosquito larvae dominating (60–70 % of total abundance) the invertebrate community in the subsidence affected creek.

The dust removal performance of two types of modified electrode electrostatic precipitator systems was evaluated and compared with that of a conventional aluminum plate electrode using laboratory-scale experiments. In the novel electrode systems, the electrode surface was coated with activated carbon using a mixed slurry containing carbon black, polyvinyl acetate, and methanol. The modification of the electrode surface improved dust precipitation by increasing the specific capacitance of the electrode. The modification also lowered the electrode’s resistance and increased its specific surface area. The optimum electrode spacing and electric voltage supply were determined using batch-type tests. In addition, dielectric insulators were applied as a partition between the oppositely charged electrodes equipped with the modified electrode plates. Multi-layered office paper cut to the same size as the electrodes was used as an insulating material. The addition of the insulator resulted in excellent improvement in the dust removal performance by minimizing the back-corona discharge phenomenon as well as doubling the dust collecting surface. Continuous dust removal tests with the three electrode systems revealed that whereas the conventional aluminum electrode exhibited 54 % dust removal, the activated carbon (AC)-coated system showed 85 % and AC-coated + insulator system showed 90 % and higher dust removal efficiency.