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.

Natural contamination has become a challenging problem in drinking water production due to metal contamination of groundwater throughout the world, and arsenic and chromium are well-known toxic elements. In this study, iron oxide-coated sand (IOCS) and granular ferric hydroxide (GFH) were used to study the effects of fulvic acid (FA) on the adsorptive removal of Cr(VI) and As(V) from synthetic groundwater. IOCS and GFH were characterized by SEM/EDS, and experiments were performed at different pH levels (6, 7, and 8). The surface of IOCS and GFH showed a high content of Fe and O (75 and 60 % of the atomic composition, respectively), suggesting that they can highly effectively adsorb Cr(VI) and As(V). Adsorption tests with the simultaneous presence of As(V) and FA, on the one hand, and Cr(VI) with FA, on the other hand, revealed that the role of FA on chromate and arsenate adsorption was insignificant at almost all pH values investigated with both adsorbents. A small influence as a result of FA was only observed for the removal of As(V) by IOCS at pH 6 with a decrease of 13 and 23 % when 2 and 5 mg/l were added to the synthetic water, respectively. It was also found that organic matter (OM) was leached from the IOCS during batch adsorption experiments. The use of FEEM revealed that humic-like, fulvic-like, and protein-like organic matter fractions are present on the IOCS surface.

The search for new bacterial consortia capable of removing PAH from the environment is associated with the need to employ novel, simple, and economically efficient detection methods. A fluorimetric method (FL) as well as high voltage electrochemiluminescence (ECL) on a modified surface of an aluminum electrode were used in order to determine the changes in the concentrations of PAH in the studied aqueous solutions. The ECL signal (the spectrum and emission intensity for a given wavelength) was determined with the use of an apparatus operating in single photon counting mode. The dependency of ECL and FL intensity on the concentration of naphthalene, phenanthrene, and pyrene was linear in the studied concentration range. The biodegradation kinetics of the particular PAH compounds was determined on the basis of the obtained spectroscopic determinations. It has been established that the half-life of naphthalene, phenanthrene, and pyrene at initial concentrations of 50 mg/l (beyond the solubility limit) reached 41, 75, and 130 h, accordingly. Additionally, the possibility of using ECL for rapid determination of the soluble fraction of PAH directly in the aqueous medium has been confirmed. Metagenomic analysis of the gene encoding 16S rRNA was conducted on the basis of V4 hypervariable region of the 16S rRNA gene and allowed to identify 198 species of bacteria that create the S4consortium. The consortium was dominated by Gammaproteobacteria (78.82 %), Flavobacteria (9.25 %), Betaproteobacteria (7.68 %), Sphingobacteria (3.76 %), Alphaproteobacteria (0.42 %), Clostridia (0.04 %), and Bacilli (0.03 %).

Thermal stability is one of the most important indexes determining the practical applications of selective catalytic reduction (SCR) catalysts. The influence of typical alkali element on the thermal stability of industrial V₂O₅-WO₃/TiO₂ catalyst is first reported in this work. The activity of the sample is measured, and physicochemical properties are characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectrum, field emission scanning electron microscope (FE-SEM), N₂ adsorption-desorption, temperature programmed desorption of NH₃ (NH₃-TPD), and in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS). The sintering and anatase-to-rutile phase transformation at high temperature will cause deactivation of SCR catalyst, and low concentration of K can increase the thermal stability. Under the same thermal treatment, the activity (380 °C) of sample deposited by K is more than three times higher than that of the fresh sample without K. Aggregation of vanadia in conventional SCR catalyst favors the sintering and anatase-to-rutile phase transformation of catalysts. Incorporation of K can modify the structure of partial V-OH and form V-OK, which hinders the aggregation of vanadia species and further increases the thermal stability of catalysts.

In this study, high-load compost leachate was successfully treated in a hybrid anaerobic baffled reactor (ABR)/electrocoagulation-flotation (ECF) system. The interaction effects of operational factors in ABR, i.e., influent chemical oxygen demand (COD), hydraulic retention time (HRT), and COD/nitrogen (N) ratio on the efficiency of COD removal and biogas production rate (BPR) were analyzed and correlated by response surface methodology (RSM). The optimum conditions of ABR were found at COD = 8250 mg/L, HRT = 46 h, COD/N ratio = 70, where COD removal and BPR reached 84 % and 76 mL/mg h, respectively. COD/N ratio and HRT were found to be the most effective parameters, respectively, on COD removal and BPR. The organic loading rate (OLR) values varied from 0.45 to 5.66 kg/m³ day. The data presented indicate that the ECF reactor successfully satisfies the discharge criteria for most of the experimental domain. The outcomes have exposed that sequential ABR/ECF reactors are a competent system in treating low- and high-strength compost leachate.

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.

Panax notoginseng is a well-known phytomedicine used all over the world. In recent years, a certain As contamination of the herb appeared in its planting area due to elevated soil As concentration. We investigated the feasibility of intercropping with Pteris vittata, an As hyperaccumulator, on the reduction of As accumulation in Panax notoginseng and As transfer and transformation in soil-plant system. Results showed that, intercropping could decrease the As concentrations of Panax notoginseng by 9.1–54.3 and 30.9–54.3% and increase the biomasses by 40.7–211.6 and 2.1–153.3 %, respectively, in the H-As (soil As 400.4 mg/kg) and M-As (soil As 85.3 mg/kg) treatments. Compared to the monoculture, the ratio of the nonspecifically adsorbed As in soil was decreased by 17.8 and 34.3 %, and the As transfer factor of Panax notoginseng was increased by 22.2 and 66.3 %, respectively, in H-As and M-As treatments. For As speciation, As(III) and As(V) could be detected at the same time only in root and xylem sap of Panax notoginseng in the H-As treatment, and intercropping could increase the ratios of As(III) by 97.8 and 72.4 %, respectively. In summary, intercropping with Pteris vittata is an applicable approach to reduce the As accumulation in Panax notoginseng.

Recent droughts in the southwestern United States have heightened the interest in using more reclaimed water for agricultural irrigation. Treated wastewater effluent is a source of irrigation water and contains many pharmaceutical microcontaminants. Currently, there is little knowledge on if these microconstituents will enter food crops and if so where they will be found within the plant. For this experiment, the uptake of 17α-ethynylestradiol, fluoxetine HCl (Prozac®), and ibuprofen within different sections of a celery stalk over a 24-h time period was examined. Results found that all of these pharmaceuticals were taken up into the celery stalks within 24 h. Ibuprofen was found to have reached concentrations of 1 μg/g within the leaves in just 1 h. Metabolites of the ibuprofen were also detected at all locations within the stalk for all time periods. The concentration of EE2 in the submerged section of the stalk was found to increase from 0.031 to 0.911 μg/g of celery in just 23 h. The EE2 began to rise higher within the stalk to reach a concentration of 8.94 ng/g about 6 in above the base after 24 h. Fluoxetine HCl concentrations rose to 0.832 μg/g of celery within the submerged section of the stalk during the 24 h. After 12 h, fluoxetine HCl was detected within the bottom 4 in of the stalk. EE2, fluoxetine HCl, and ibuprofen all exhibit potential for uptake within food crops. Further studies on additional food crops and pharmaceuticals would be required to assess the full risk posed to human eating food crops irrigated with treated wastewater effluent.

Winnipeg is a city in the Canadian Prairies with a population of about 600,000. Like many other cities and towns in this region of Canada, the city is surrounded by agriculture. Weekly bulk deposition samples were collected from May to September in 2010 and 2011 and analyzed for 43 pesticides used in Prairie agriculture. Fourteen herbicides, five herbicide metabolites, two insecticides, and two fungicides were detected with 98.5 % of the samples containing chemical mixtures. Glyphosate is the most widely used pesticide in Prairie agriculture and accounted for 65 % of the total pesticide deposition over the 2 years. Seasonal glyphosate deposition was more than five times larger in 2011 (182 mm rain) than 2010 (487 mm rain), suggesting increased glyphosate particulate transport in the atmosphere during the drier year. The seasonal deposition of ten other frequently herbicides was significantly positively correlated with the amount of herbicides applied both in and around Winnipeg (r = 0.90, P < 0.001) and with agricultural herbicide use around Winnipeg (r = 0.63, P = 0.05), but not with agricultural herbicide use province wide (P = 0.23). Herbicides 2,4-D (2,4-dichlorophenoxyacetic acid), dicamba, and mecoprop had known urban applications and were more consistently detected in samples relative to bromoxynil and 2-methyl-4-chlorophenoxyacetic acid (MCPA) whose frequency of detections decreased throughout August and September. The Canadian Water Quality Guidelines for irrigation water were frequently exceeded for both dicamba (75 %) and MCPA (49 %) concentrations in rain. None of glyphosate concentrations in rain exceeded any of the Canadian Water Quality Guidelines established for this herbicide.

Biosorption is a low-cost green technology for water pollution decontamination. Recently, new adsorbent materials (raw or modified) were synthesized and tested in a wide variety of different pollutants. Among them, researchers pay attention on an alternative use of composts. The major use of composts is as soil amendments to improve the fertility of soils. For the first time in literature, the present review article gathers information about the applicability of compost materials as biosorbents in batch modes. For this purpose, equilibrium modeling and isotherm, kinetic, and thermodynamic studies were discussed in details. Moreover, many parameters such as temperature, pH, and contact time were also analyzed. The main pollutants studied in this work are dyes and heavy metals either in single- or multi-component systems.