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4-1.0%. Microbial community composition and nitrogen removal mechanisms were related to overall level and local zonation of dissolved oxygen, mixed liquor suspended solids concentration, nitrogen and organic loadings, and solids retention time. buy TAK-242 Low dissolved oxygen and low organic and nitrogen loadings favored growth of Nitrospira.The occurrence of boron in water and its inefficient removal are the key issue in desalination and water treatment. Adsorption by fixed-bed column is usually used to remove mineral and organic contaminants from the aqueous phase. The adsorption of the boron onto activated carbon, prepared from palm bark, is studied. Batch adsorption experiments are developed to determine the equilibrium time and the best isotherm model. The kinetic adsorption data can be described by the second-order equation. Among the adsorption isotherm models, Langmuir and Sips models give better fit of the equilibrium data. The calculated thermodynamic parameters show that the boron adsorption is exothermic in nature. The effects of inlet boron concentration, feed flow rate and weight of activated carbon on the fixed-bed adsorption are determined by two-level factorial experimental design. Breakthrough and saturation times are higher at high adsorbent weight and low flow rates. The increase of boron initial concentration decreases breakthrough and saturation times. The volume treated per gram of activated carbon is higher at lower initial concentrations and at higher adsorbent weight. Compared to other models, the Yan model fits better the experimental data of the breakthrough curves with R2 of 0.993.Autotrophic nitrifying granular sludge (ANGS) was cultivated by gradually decreasing the influent organics and adding exogenous nitrifying bacteria. Under the strategy, ANGS was domesticated within 36 days. Stability of the seed heterotrophic granules decreased significantly during conversion of organic wastewater to inorganic ammonia wastewater. Obvious granular breakage was observed during these days. However, the granular debris still had good settlement performance. With microbes gradually acclimated to the new environment, the debris provided a large number of carriers for the attached growth of the exogenous nitrifying bacteria, and they replaced the heterotrophic bacteria and became the dominant species. The domesticated ANGS showed good nitrification performance during the 37th to the 183rd day (ammonia nitrogen load between 0.28 and 0.29 kg/m3 · d). The removal rate of ammonia nitrogen was usually more than 95%, and nitrite accumulation rate was always larger than 50%. However, nitrification ability was gradually lost with the increase of the ammonia nitrogen load (0.3-0.64 kg/m3 · d) from the 184th day, and it almost approached the influent ammonia nitrogen at the 269th day. Interestingly, good structure stability of the ANGS was maintained during long-term operation, and the ANGS became smoother and denser at the end of the experiment.The biodegradation of polyacrylamide (PAM) includes the hydrolysis of amino groups and cleavage of the carbon chain; however, the effect of molecular weight on the biodegradation needs further investigations. In this study, biodegradation of low molecular weight PAM (1.6 × 106 Da) was evaluated in two aerobic (25 °C and 40 °C) and two anaerobic (35 °C and 55 °C) reactors over 100 days. The removal of the low molecular weight PAM (52.0-52.6%) through the hydrolysis of amino groups by anaerobic treatment (35 °C and 55 °C) was much higher than that of the high molecular weight (2.2 × 107 Da, 11.2-17.0%) observed under the same conditions. The molecular weight was reduced from 1.6 × 106 to 6.45-7.42 × 105 Da for the low molecular weight PAM, while the high molecular weight PAM declined from 2.2 × 107 to 3.76-5.87 × 106 Da. The results showed that the amino hydrolysis of low molecular weight PAM is easier than that of the high molecular weight one, while the cleavage of its carbon chain is still difficult. The molecular weights of PAM in the effluents from the two aerobic reactors (25 °C and 40 °C) were further reduced to 4.31 × 105 and 5.68 × 105 Da by the biofilm treatment, respectively. The results would be useful for the management of wastewater containing PAM.Boron removal from water containing 5 mg L-1 of boron using electrodialysis (ED) was studied as a function of several parameters such as flow rates, initial pH, coexisting anions and ED time. An ED cell, equipped with three cation exchange membranes (fumasep FKB) and two anion exchange membranes (fumasep FAB), was applied. The central composite design, which is the standard design of response surface methodology, was used to evaluate the effects and interactions of studied factors on boron removal efficiency. The effectiveness of the considered design parameters was well examined to find the optimum condition. The experimental data obtained were analyzed by analysis of variance for the polynomial model with 95% confidence level. Boron removal by ED showed to be independent of the electrodialysis time, whereas flow rate as well as the pH of the feed solution and also the coexisting anions on the feed solution play a significant role on the deboronation efficiency. According to the desirability function, the maximum response of 43.5% was predicted for boron removal at a pH equal to 10, a flow rate of 10 L h-1, a ratio between sulfates and that of boron equal to 2 and a reaction time of 25 minutes.Polycyclic aromatic hydrocarbons (PAHs) are hydrophobic organic compounds that are generally absorbed on organic fraction of soils. It is known that some PAHs, which can pass to air, soil, water and food as a result of natural or anthropogenic processes, have carcinogenic, toxic and mutagenic effects on humans and animals. One of the important steps that is identified in the transition takes place during agricultural production. Greenhouses are commonly used as a type of agricultural production especially during the winter season in mid and temperate climates. Greenhouse cultivation is abundant in Antalya Aksu Region in Turkey. Two sampling campaigns (autumn and winter) were carried out to sample the soils in 53 glass and polyethylene covered greenhouses. The samples were analysed with gas chromatography-mass spectrometry (GC/MS) for 16 PAHs. The result showed that four ring PAHs were dominant in the region. In the winter season, PAHs concentrations increase because of low volatility of motor vehicle exhaust related PAHs in the atmosphere and of coal and wood combustion emissions used in the heating of greenhouses and surrounding village houses.