BACKGROUND, AIM, AND SCOPE: Textile industry produces wastewater which contributes to water pollution since it utilizes a lot of chemicals. Preliminary studies show that the wastewater from textile industries contains grease, wax, surfactant, and dyes. The objective of this study was to determine the treatment efficiency of the nickel catalysts supported on hydrotalcites in three-dye model compounds and two types of wastewater. MATERIALS AND METHODS: Hydrotalcites were employed to prepare supported nickel catalysts by wetness impregnation technique. Metal loadings from 1 to 10 wt% were tested. Catalysts were characterized by several techniques. They were tested in a catalytic wet air oxidation of three dyes and two wastewaters with different origins. RESULTS AND DISCUSSION: It could be observed that the higher the metal content, the lower the BET area, possibly due to sintering of Ni and the consequent blocking of the pores by the metal. In addition, metallic dispersion was also higher when the metal content was lower. Dye conversion was more than 95% for every catalyst showing no differences with the nickel content. A high degree of dye conversion was achieved. Wet air oxidation (WAO) and catalytic wet air oxidation (CWAO) processes have been proved to be extremely efficient in TOC removal for wastewaters. CONCLUSIONS: The CWAO process can be used to remove dyes from wastewater. Three different dyes were tested showing satisfactory results in all of them. TOC degradation and dye removal in the presence of the catalyst were effective. Also, the HTNi catalyst is very active for organic matter and toxicity removal in wastewaters.

BACKGROUND, AIM, AND SCOPE: Indiscriminate use of insecticides leads to environmental problems and poses a great threat to beneficial microorganisms. The aim of the present work was to study chlorpyrifos degradation by a rice field cyanobacterium Synechocystis sp. strain PUPCCC 64 so that the organism is able to reduce insecticide pollution in situ. MATERIAL AND METHODS: The unicellular cyanobacterium isolated and purified from a rice field was identified by partial 16S rRNA gene sequence as Synechocystis sp. strain PUPCCC 64. Tolerance limit of the organism was determined by studying its growth in graded concentrations (2.5–20 mg/L) of chlorpyrifos. Chlorpyrifos removal was studied by its depletion from the insecticide supplemented growth medium, and its biodegradation products were identified in the cell extract, biomass wash, and growth medium. RESULTS AND DISCUSSION: The organism tolerated chlorpyrifos up to 15 mg/L. Major fraction of chlorpyrifos was removed by the organism during the first day followed by slow uptake. Biomass, pH, and temperature influenced the insecticide removal and the organism exhibited maximum chlorpyrifos removal at 100 mg protein/L biomass, pH 7.0, and 30°C. The cyanobacterium metabolized chlorpyrifos producing a number of degradation products as evidenced by GC-MS chromatogram. One of the degradation products was identified as 3,5,6-trichloro-2-pyridinol. CONCLUSION AND RECOMMENDATIONS: Present study reports the biodegradation of chlorpyrifos by Synechocystis sp. Biodegradation of the insecticide by the cyanobacterium is significant as it can be biologically removed from the environment. The cyanobacterium may be used for bioremediation of chlorpyrifos-contaminated soils.

Purpose Hexachlorocyclohexane (HCH) isomers (α-, β- and γ- (Lindane)) were recently included as new persistent organic pollutants (POPs) in the Stockholm Convention, and therefore, the legacy of HCH and Lindane production became a contemporary topic of global relevance. This article wants to briefly summarise the outcomes of the Stockholm Convention process and make an estimation of the amount of HCH waste generated and dumped in the former Lindane/HCH-producing countries. Results In a preliminary assessment, the countries and the respective amount of HCH residues stored and deposited from Lindane production are estimated. Between 4 and 7 million tonnes of wastes of toxic, persistent and bioaccumulative residues (largely consisting of alpha- (approx. 80%) and beta-HCH) are estimated to have been produced and discarded around the globe during 60 years of Lindane production. For approximately 1.9 million tonnes, information is available regarding deposition. Countries are: Austria, Brazil, China, Czech Republic, France, Germany, Hungary, India, Italy, Japan, Macedonia, Nigeria, Poland, Romania, Slovakia, South Africa, Spain, Switzerland, Turkey, The Netherlands, UK, USA, and former USSR. The paper highlights the environmental relevance of deposited HCH wastes and the related POPs' contaminated sites and provides suggestions for further steps to address the challenge of the legacy of HCH/Lindane production. Conclusion It can be expected that most locations where HCH waste was discarded/stockpiled are not secured and that critical environmental impacts are resulting from leaching and volatilisation. As parties to the Stockholm Convention are legally required to take action to stop further POPs pollution, identification and evaluation of such sites are necessary.

Purpose The Pb absorption processes on a heavy textured calcareous soil, typical of central Italy, were studied using synchrotron X-ray absorption spectroscopy (XAS) in order to probe, at molecular scale, the structure and chemical nature of Pb in contaminated soils and achieve precise description of Pb ions localization into these contaminated soils. Materials and methods In order to distinguish the role of the different components of soils in Pb retention, samples were prepared from the original soils removing the carbonate fractions, the organic matter, the metal oxides, or selecting the clay fractions. Then these samples were fortified with Pb simulating the natural interactions processes of heavy metal solutions with soils. The quantitative analysis of near edge (XANES) as well extended (EXAFS) regions of Pb LIII edge absorption spectra, in comparison with Pb XAS data of selected reference compounds, allowed the precise determination of local structure and chemical environment of Pb ions in these soil samples. Results Four components were individuated as the major responsible of Pb retention in calcareous soils: the carbonates, the metal oxide surfaces, the organic matter, and the colloidal inorganic surfaces containing clay components. The structural analysis suggests that, within these experimental conditions, the Pb adsorbed on the soil is generally present as Pb hydroxide with poor crystallization degree. However, the presence of carbonates (CaCO₃) induces the co-precipitation of PbCO₃-like phases with some degree of crystallinity.

Background, aim, and scope The Jiangsu section of the Yangtze River is the downstream of the whole river, serving as an important drinking water source. Persistent toxic substances (PTS), from the industries such as automobile, textile, chemical, and electronic production, are not listed in the National Standard yet and not monitored and controlled. However, pollution of PTS can threaten the environment and human health. In order to understand the pollution status of the PTS contamination and recommend future rationalization of countermeasure, the PTS including organochlorine pesticides (OCPs), polyaromatic hydrocarbons (PAHs), polychlorobiphenyls (PCBs), and phthalates (PAEs) were investigated. Materials and methods Samples were collected at 15 sites from five main stream sections of the Yangtze River in Jiangsu Province. PTS were extracted using solid phase extract method. The analysis of OCPs, PCBs was performed using GC/ECD and PAHs, PAEs was performed by GC/MS. Results and discussions The method detection limits are low and the recoveries are from 58.1% to 110.3%. The total concentrations of OCPs, PCBs, PAHs, and PAEs were 0.27∼2.15 ng l⁻¹, <0.21∼44.4 ng l⁻¹, 0.012∼3.576 μg l⁻¹ and 0.178∼1.474 μg l⁻¹, respectively. γ-HCH, PCB28, PCB101, phenanthrene, anthracene, di-n-butyl phthalate, diethyl phthalate, and di-(2-ethylhexyl) phthalate are the major detected PTS. The concentration of most of the PTS was below the environmental quality standards for surface water of China. Conclusions The pollution status of OCPs, PCBs, PAHs, and PAEs were analyzed. PTS contamination levels of the five main stream sections were relatively low.

Introduction and aims The Chilean Altiplano ecosystem is conserved free from contaminants and pollutants because of the absence of major local human activities such as agriculture or other industries. We studied the effects of paraoxon on proliferation and apoptosis of testicular cells during active spermatogenesis in Dugesia gonocephala collected from a pristine river (Guacollo) in the Altiplano region nearby Visviri town, Chile. Materials and methods Adult planarians were incubated in varying concentrations of paraoxon (0.8, 0.4, 0.04, 0.004, and 0.0004 mM) for 4 h. After 3 h of incubation, bromodeoxyuridine (BrdU) was added. Effects on cell proliferation (BrdU) and apoptosis (Apaf-1) were determined by immunohistochemistry. Results Paraoxon concentrations of 0.4 and 0.8 mM caused 100% mortality in the respective treatment groups. The lowest tested concentration (0.0004 mM) caused a significant increase on cell proliferation in the seminiferous tubules, as well as an increase in the number of apoptotic cells. All other tested concentrations significantly inhibited cell proliferation and induced apoptosis. Conclusions Paraoxon inhibits DNA synthesis and induces apoptosis during spermatogenesis in adult planarians from a high-altitude, pollution-free environment. This could suggest its use as a biosensor or biomarker for contamination with agro pesticides.

Background Airborne fine particulates (PM 2.5) and its associated polycyclic aromatic hydrocarbons (PAHs) are reportedly hazardous in urban environment due to the presence of multiple emission sources. Methods In this study, fine particulates collected from fourth largest metropolitan city of India, Chennai, were extracted and analyzed for 11 PAHs by high-performance liquid chromatography equipped with a fluorescence detector. Results PM 2.5 values varied between 27.2 and 190.2 μg/m³, while average concentration of particle-associated PAHs determined was in the range from 325.7 to 790.8 ng/m³, which signaled an alarming pollution level in Chennai. Conclusions Factor analysis suggested vehicular emissions inclusive of petrol- and diesel-driven engines as probable sources.

Purpose The anti-inflammatory drug naproxen (NPX) has been found as a micropollutant in river water downstream the discharge points of wastewater treatment plants (WWTP). In this study, rainbow trout (Oncorhynchus mykiss) was exposed to NXP and the uptake and metabolism of the drug was studied. Methods Following exposure through intraperitoneal injection (i.p., 0.5 mg NPX/100 g fish biomass) and through water (1.6 μg L⁻¹), the bile was collected and analyzed with various LC-MS/MS methods. The identification of the formed metabolites in i.p. injected fish was based on the exact mass determinations by a time-of-flight mass analyzer (Q-TOF-MS) and on the studies of fragments and fragmentation patterns of precursor ions by an ion trap mass analyzer (IT-MS). Results No matter the exposure route, the main metabolites were found to be acyl glucuronides of NPX and of 6-O-desmethylnaproxen. Also, unmetabolized NPX was detected in the bile. The total bioconcentration factors (BCFtotal₋bile) of NPX and the metabolites in the bile of fish exposed through water ranged from 500 to 2,300. Conclusion The findings suggest that fish living downstream WWTPs may take up NPX and metabolize the compound. Consequently, NPX and its metabolites in bile can be used to monitor the exposure of fish to NPX.

Purpose Industrial wastewater flow caused operational difficulties in the wastewater treatment plant in Debrecen, Hungary. Bioaugmentation was successfully applied to maintain effluent quality in the periods when wastewater of high starch content was accepted, but, at the end of 2008, the nitrification capacity of the plant decreased considerably due to improperly pre-treated pharmaceutical wastewater. Methods and material Dynamic simulations were carried out in a prototype programme developed by the Environmental Expert System Research Group at the University of Pannonia, Hungary. Several parameters for heterotrophic biomass were adjusted in function of time, and the specific growth rate of autotrophic biomass was altered in function of time and temperature in order to describe the effects of inoculation and toxic influence. Simulations were carried out with both constant and adjusted parameters. Results Though results on effluent COD of the different modelling versions were similar, the ammonia concentration fitted the measured data only when modified parameters were used. The study revealed that the autotrophic biomass had slowly adapted to the toxic compound. Different control strategies of aeration and decreased excess sludge removal rate were tested to enhance the nitrification in the critical time intervals. The amount of ammonia and inorganic nitrogen decreased in all cases while the oxygen demand increased to a maximum of 10.1%. Conclusions Reducing excess sludge removal rate gave satisfactory results even without changing aeration. Further improvement could be achieved by introducing aeration into the post-denitrification reactor. The combination of the two modifications can compensate for the effect caused by toxicity.

Purpose Spillage of petroleum hydrocarbons causes significant environmental pollution. Bioremediation is an effective process to remediate petroleum oil contaminant from the ecosystem. The aim of the present study was to reclaim a petroleum oil-contaminated soil which was unsuitable for the cultivation of crop plants by using petroleum oil hydrocarbon-degrading microbial consortium. Materials and methods Bacterial consortium consisting of Bacillus subtilis DM-04 and Pseudomonas aeruginosa M and NM strains were seeded to 20% (v/w) petroleum oil-contaminated soil, and bioremediation experiment was carried out for 180 days under laboratory condition. The kinetics of hydrocarbon degradation was analyzed using biochemical and gas chromatographic (GC) techniques. The ecotoxicity of the elutriates obtained from petroleum oil-contaminated soil before and post-treatment with microbial consortium was tested on germination and growth of Bengal gram (Cicer aretinum) and green gram (Phaseolus mungo) seeds. Results Bacterial consortium showed a significant reduction in total petroleum hydrocarbon level in contaminated soil (76% degradation) as compared to the control soil (3.6% degradation) 180 days post-inoculation. The GC analysis confirmed that bacterial consortium was more effective in degrading the alkane fraction compared to aromatic fraction of crude petroleum oil hydrocarbons in soil. The nitrogen, sulfur, and oxygen compounds fraction was least degraded. The reclaimed soil supported the germination and growth of crop plants (C. aretinum and P. mungo). In contrast, seeds could not be germinated in petroleum oil-contaminated soil. Conclusions The present study reinforces the application of bacterial consortium rather than individual bacterium for the effective bioremediation and reclamation of soil contaminated with petroleum oil.