Organic Pollutants In Effluent Research Articles

Unveiling the existence and ecological hazards of trace organic pollutants in wastewater treatment plant effluents across China

The presence of trace organic pollutants in the effluent of wastewater treatment plants (WWTPs) poses considerable risks to aquatic organisms and human health. A large-scale survey of 302 trace organic pollutants in the effluent of 46 Chinese WWTPs was conducted to gain an improved understanding of their occurrence and ecological risks. The survey data showed that 216 compounds in 11 chemical classes had been detected in effluents. The sum concentrations of the trace contaminants in effluent ranged from 1,392 ng/L to 35,453 ng/L, with the maximum concentration of perfluoroalkyl substances (PFASs) recorded as the highest (30,573 ng/L), which was markedly less than the reported 185,000 ng/L for the 38 American WWTPs. The concentration of bisphenol analogs (BPs) was up to 4,422 ng/L, significantly higher than those reported in France, Germany, Japan, Korea, and the U.S. PFASs and BPs were the major pollutants, accounting for 59% of the total pollution. Additionally, a total of 119 contaminants were found to have ecological risks (RQ > 0.01). Among these, 23 contaminants (RQ > 1.0) warrant higher attention and should be prioritized for removal. This study lists valuable information for controlling contaminants with higher priority in WWTP effluent in China.

Intimate Coupling AgI/AgIO3 Heterojunction Photocatalysts with Excellent Visible-Light-Driven Photocatalytic Activity

Photodegrading toxic organic pollutants in effluents over semiconductor photocatalysts is friendly and promising. The key is to develop a universally powerful and stable photocatalyst. In this work...

Characterization and application of dried neem leaf powder as a bio-additive for salt less animal skin preservation for tanneries.

Sodium chloride (NaCl) is commonly used as a curing/preservative agent for raw hides and skins in tanneries and is removed through a soaking process with total dissolved solids (TDS) and other organic pollutants in effluent, causing significant pollution load to the environment. Hence, the present study evaluated to apply dried neem leaf powder (DNL) as an additive to reduce the usage of salt in skin processing and preservation. To make certain of DNL antimicrobial properties, solvent extracts were performed against proteolytic bacteria isolated from raw skins. Initial characterization of DNL revealed the presence of bioactive compounds nimbolide and dehydro salannol and acetone extract with 16.9-mm, 10-mm and 8-mm zone of inhibition against Salmonella sp., E. coli sp. and Bacillus sp. identified using phenotypic conventional biochemical screening method. Further, skin curing experiments were carried out using four different treatments of DNL (10% 15%, 20% and 25% w/w) along with 15% w/w of conventional salt to obtain an optimum concentration for pilot-scale studies. Thus, the application of optimal DNL (15%) and salt (15%) resulted in no physical changes such as smell and hair slip and was taken for further studies for hydroxyproline activity, pollution load and organoleptic properties along compared with control 40% salt. DNL-aided salt less preservation of freshly flayed goat skins at ambient condition showed no hair slip or putrefaction during the preservation period with significant reduction of TDS (86%) and chloride (71%) in soak liquors compared to conventional salt preservation and enhanced organic load requiring additional treatment. However, the application of the organoleptic, physical and hydrothermal properties of resulting leathers produced from the DNL applied skins was on par with results of leather obtained from conventional salt. Thus, our results demonstrate DNL-aided salt less preservation method is able to reduce the amount of salt for preservation of goat skins significantly, leading to reduced salinity issues during leather processing.

Improved degradation of textile effluents via the synergetic effects of Cu-CeO2 catalysis and non-thermal atmospheric pressure plasma treatment

The direct discharge of industrial textile effluents is increasingly constituting a major burden on the environment. The development of an effective treatment for the degradation of hazardous organic pollutants in effluents is therefore highly needed. In this paper, the synergetic effects of copper-doped cerium oxide (Cu-CeO2) nanoparticles (NPs) and non-thermal atmospheric pressure plasma (NTAPP) treatment were thoroughly examined on the degradation efficiency of reactive black-5 (RB-5) dye in aqueous solution and textile effluent. Initially, Cu-CeO2NPs were synthesized by a hydrothermal method and further characterized by field emission scanning electron microscopy (FE-SEM), Fourier-transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). The degradation efficiency of the combined plasma/Cu-CeO2 catalysis treatment was examined by UV–Vis spectroscopy as a function of the treatment time.Optical emission spectrometry (OES) was used to identify the generated primary and secondary reactive species such as OH●, O, H and N2* in the plasma jet. The presence of OH● radicals and H2O2in treated RB-5 aqueous solution was also quantified spectroscopically. Furthermore, the variation in the pH, electrical conductivity and total organic carbon (TOC) was also studied. All combined results revealed that plasma advanced oxidation processes together with the Cu-CeO2 catalytic performance have triggered the formation of higher concentrations of various reactive species which in turn improved the degradation efficiency of the RB-5 and direct effluent and suppressed the formation of harmful intermediates.This was further corroborated by the non-toxicity of the treated solutions when in contact S. aureus and E. coli bacteria. Overall, it can be concluded that the distinctive combination of Cu-CeO2 and plasma-assisted processes is ideally required in different textile industries as a highly effective treatment of effluents before discharging.

Removal of Organic Pollutants from Effluent of Anaerobic Digester Using Hydrochars Produced from Faecal Simulant and Sewage Sludge

Hydrochars produced from hydrothermal carbonisation of faecal simulant (FS) at 180 °C for 30 min and sewage sludge treated via CAMBI process at 165 °C for 30 min were used for adsorption of organic pollutants in effluent from an anaerobic digester (AD). The adsorption potential of the hydrochars investigated was compared with that of a commercial powdered activated carbon (PAC). It was found that the CAMBI and FS hydrochars were effective only after chemical activation. KOH activation increased chemical oxygen demand (COD) removal from 33.0 to 59.6% and 75.2% for FS and CAMBI, respectively. Extra activation with HCl improved the adsorption efficiency of FS, increasing COD removal to 79.3%, but not for the CAMBI hydrochar even though its surface area was increased. Acidic pH aided organics removal for both hydrochars. PAC adsorption capacity was the highest (> 90%), and this was not affected by pH. All the adsorbents could successfully remove the organics in a very short time as 30 min. The optimum dosage of the hydrochars to reach a high uptake of organics was 30.0 g/L. The adsorption reaction followed a pseudo-second-order kinetic model for all the hydrochars. The adsorption onto the hydrochars correlated well with Temkin isotherm model and followed a type II and IV isotherm type, except PAC which was described by the Langmuir isotherm with a high adsorption capacity of 400.0 mg/g. The study demonstrated that hydrochars of FS and CAMBI activated with KOH are efficient and sustainable adsorbents for the removal of organics from AD effluent.

Ny-Ålesund-oriented organic pollutants in sewage effluent and receiving seawater in the Arctic region of Kongsfjorden

Ny-Ålesund, one of four permanent settlements on Spitsbergen in Svalbard, is a research town that includes scientific institutes from many countries. Because of daily-used chemicals (e.g., pharmaceutical and personal care products (PPCPs)) used by residents in the area, generated sewage is considered as a point source in the Kongsfjorden. The aim of the present study was to identify and quantify organic pollutants in the effluent and along the shoreline and offshore via target, suspect, and non-target screening using liquid chromatography–high-resolution mass spectrometry. We tentatively identified 30 compounds using the suspect and non-target screening methods in effluent samples from our first visit to the settlement in 2016. Among these, 3 were false positive, 24 were confirmed, and the 3 remaining compounds were not confirmed because of a lack of reference standards. Of the confirmed, 21 were quantifiable and considered target compounds for the 2nd year study. The quantified compounds in the effluent samples in 2017 totaled 17, including PPCPs, pesticides, perfluorinated compounds, and their metabolites. Some of the compounds, such as caffeine, paraxanthine/theophylline, acetaminophen, cetirizine, diethyl toluamide (DEET), and icaridin, were also detected in the receiving seawater. The concentration range was from 4 to 280,000 ng/L in the effluent and 2–98 ng/L in the seawater. Other 24 compounds were tentatively identified in the second-year effluent samples. Five were further confirmed using reference standards. Prioritization was performed on the 47 substances screened in Ny-Ålesund using the exposure and toxicity index. As the result, the top seven substances of concern present were perfluorooctanesulfonic acid (PFOS), triphenyl phosphate (TPHP), irbesartan, DEET, acetaminophen, caffeine, and paraxanthine/theophylline. As the effluent was identified as a source of the concerned organic pollutants, an emission reduction strategy should take place for protection of Arctic Fjorden environment.

Characterization of pharmaceuticals industrial effluent using GC\u2013MS and FT-IR analyses and defining its toxicity

The physicochemical analysis of collected effluent sample for different parameters shown results as pH (pH 5.6 ± 0.11) slightly acidic, high conductivity (1563.34 ± 176 μs cm−1), total dissolved solids (920.34 ± 137 mg L−1), high BOD (7253.34 ± 1022 mg L−1), and COD (756.67 ± 1124 mg L−1) in the effluent sample. The results of heavy metals concentration are viz. as [Cu (1.98–2.56), Co (0.26–0.53), Cd (0.10–0.50), Ni (0.04–0.07), Pb (0.58–1.2), Mn (0.58–1.05), Cr (1.47–1.51), Zn (2.61–3.5), Fe (1.72–2.13), As (0.05–0.09), and Hg (0.003–0.006)]. Results revealed the higher concentration of BOD, COD, TDS, and conductivity and also the concentration of lead. Results of GC–MS also confirmed the high levels of organic pollutants in effluent. Further the effluent toxicity was evaluated by employing genotoxocity assays with the use of Allium cepa L. (onion) root tip cells. Genotoxicity measured mitotic index (MI) and chromosomal aberrations (CAs) in root tip cells obtained after treatment with effluent of 6.25, 12.5, and 25% concentration (v/v). The results of root growth test showed that inhibition of root growth occurred at effluent concentration ≥ 50% (v/v). The lowest MI was recorded (MI = 9.6%) in 25% of effluent concentration, showing a significant reduction in mitotic index compared with control which MI = 64.1%. Further, the chromosomal aberration was investigated in root tip cell after treating with different concentration ranges of effluent exhibiting various CA, viz. c-mitosis, chromosome loss, chromosome break, micronucleated cells, etc. The result suggests that the effluent contained toxic constituents, which imposed cytotoxic and genotoxic hazard.

Dynamic soft sensing of organic pollutants in effluent from UMIC anaerobic reactor for industrial papermaking wastewater

With the rapid development of paper industry, the pressure of environmental pollution is going more and more serious. Recently, resource utilization of wastewater by anaerobic digestion has become a feasible way to solve this problem. In order to maintain the safe and efficient production of the process, a novel adaptive soft sensor model was developed to infer the chemical oxygen demand (COD) of paper mill effluent in this paper. First, the principal component analysis technique was performed in this model so as to eliminate the col-linearity between the process variables and accordingly obtain the low-dimensional feature principal component. Then, the least square support vector machine method was used to construct a quantitative regression model between principal component and the effluent COD. Along with it, particle swarm optimization was implemented to search for the best value of the LSSVM model parameters, namely the kernel parameters and the regularization factor. Finally, an online calibration strategy was designed to adapt to the process dynamic changes in an adaptive iterative manner. When the constructed model tested for performances in a full-scale factory, the average relative deviation and maximum deviation are 1.80% and 6.26%, respectively. The experimental results show that this proposed soft sensor model is featured with high accuracy and strong dynamic stability, and it can provide good guidance for COD prediction and optimal control of paper mill wastewate treatment.

Spatial distribution and comprehensive evaluation of emerging organic pollutants in effluents from wastewater treatment plants in northern cities of China

Spatial distribution and comprehensive evaluation of emerging organic pollutants in effluents from wastewater treatment plants in northern cities of China

Extraction of ligninolytic enzymes from novel Klebsiella pneumoniae strains and its application in wastewater treatment

The presence of lignin and its derivatives in pulp effluent increases the pollution load on the environment. With an aim of better degradation and decolourization of wastewater, this study proposes the utilization of different ligninolytic enzymes from novel bacterial strains. Four novel bacterial strains of Klebsiellapneumoniae (K. pneumoniae strains NITW715076, NITW715076_1, NITW715076_2 and NITW715076_3) were isolated and identified. The ligninolytic enzymes were characterized by plate assay method. For the optimization of various process parameters of effluent sample, different approaches were used like one factor at a time and statistical optimization through response surface methodology (RSM). Further to validate the above data, enzyme activity, total phenolic concentration, GC–MS analysis and seed germination test were also performed. The ligninolytic enzymes produced were characterized as laccase and Manganese peroxidase (MnP). In lignin degradation and decolourization studies, consortia 1 (K. pneumoniae NITW715076_2 + K. pneumoniae NITW715076_1) (82.31%) was found more effective when compared to axenic culture (K. pneumoniae NITW715076_2) (74.1%). In RSM studies, Laccase and MnP activities were increased by 20% and 18%, respectively, as compared to one factor at a time optimization method. In addition, the enzyme activity for laccase and MnP after prediction by RSM was found 53338 IU/L and 147900 IU/L, respectively. The R2 values for both the enzymes were found to be significant. Further, GC–MS analysis also showed the degradation of different organic pollutants in effluent. Lastly, the seed germination test using consortia 1 corroborated the evidence of detoxification of industrial effluent. Effluent treated by consortia 1 showed better results in degradation and decolourization of lignin and their derivatives. Therefore, consortia 1 can be used for various industrial purposes like fruit juice clarification, diagnostic purposes and enhanced bioethanol production.

Synthesis and characterization of the removal of organic pollutants in effluents.

The use of a large number of organic pollutants results in the accumulation of effluents at the places of production and the environment. These substances are, therefore, dangerous for living organisms and can cause heavy environmental damage. Hence, to cure these problems certain methods were used for the elimination of organic effluents. Indeed, the methods of elimination through magnetic adsorption and/or separation prove to be effective in the treatment of certain wastes, but the effectiveness of each one of these methods depends on several characteristics and also present limitations according to the pollutants they adsorb. This review examines on the one hand the capacity of certain elements of these methods in the elimination of certain pollutants and on the other hand the advantages and limits of these methods. Elements like biochars, biosorbents and composite materials are used due to their very strong porosity which makes it possible for them to develop an important contact surface with the external medium, at low costs, and the possibility of producing them from renewable sources. The latter still run up however against the problems of formation of mud and regeneration. Depollution by magnetic separation is also used due to its capacity to mitigate the disadvantages of certain methods which generally lead to the formation of mud and overcoming also the difficulties like obtaining an active material and at the same time being able to fix the pollutants present in the effluents to treat and sensitize them to external magnetic fields.

Geochemical Characterization of Organic Pollutants in Effluents Discharged from Various Industrial Sources to Riverine Systems

The detailed characterization of the organic composition of industrial effluents discharged from various industrial branches and the distribution of the emitted pollutants in the surface waters in North Rhine-Westphalia have been done with the use of non-target screening analyses. Based on the characterization of molecular structures of wastewater constituents, their quantification as well as the available information on their origin and industrial applications, the identification of typical organic representatives for petrochemical and food effluents has been performed. Among a wide range of hydrocarbons detected in the petrochemical effluents, several novel organic wastewater constituents have been found for the first time. In the effluents from paper production plant, potential industrial indicators were distinguished, such as resin acids (abietic and dehydroabietic acids) and photoinitiators (Irgacure 184). The monitoring of the behaviour of certain environmentally relevant and newly described pollutants in the contaminated river systems allowed the identification of several industrial site-specific markers. Particularly, 2-(chloromethyl)-1,3-dioxolane, an unknown contaminant, exclusively found in the effluents from a chemical production complex, was present in the river under discharge at high concentrations downstream the contamination source. The comprehensive and detailed evaluation of the anthropogenic markers in the industrial effluents is a promising tool for the environmental assessment of industrial emissions, especially if accompanied with toxicological and ecotoxicological investigations of novel environmental contaminants.

The removal of COD from bleaching effluents by Fenton's reagent: Effect of system parameters and kinetic study

Fenton's reagent was now being used as a post-treatment procedure to eliminate the intractable pollutants in the bleaching effluents from pulp mills. To establish cost-efficient operating conditions for the application of Fenton's reagent, the effects of operating conditions such as the dosages of H2O2, the molar ratio of [Fe2+]/[H2O2], the value of solution pH and the system temperature on the removal of COD were evaluated systematically. The results showed a suitable operating condition that yields 88.7% of COD removal was obtained at [H2O2] = 4COD(mM L−1), [Fe2+]/[H2O2] = 20:1, pH3, 90°C, reaction time 120 min. A kinetic study was carried out using a modified pseudo-first-order model. The results showed the COD removal for bleaching effluents by Fenton's reagent followed the first-order reaction kinetics, and the activation energy Ea was detected to be 1.68 kJ mol−1 based on the experiments performed at different temperatures. In addition, the results of GC/MS analysis showed organic pollutants in effluents were degraded into organic acids of lower molecular weight under the attack of hydroxyl radicals generated in Fenton's reaction. The results of biodegradability assay indicated the bio-toxic substances in the bleaching effluents were eliminated. © 2010 American Institute of Chemical Engineers Environ Prog, 2011

Application of pine bark as a sorbent for organic pollutants in effluents

Nowadays trace organic pollutants represent a major concern in water treatment systems. Activated carbon has been used for most applications aiming at the reduction of these kind of compounds in aqueous effluents, but regeneration needs and high operation costs led to a renewed interest in the search for alternative sorbents. Pine bark is an excedentary raw material from sawmills in Portugal, and therefore a profitable natural resource that has already been successfully tested in the adsorption of organochlorines from contaminated water. This study aims at characterizing the pine bark surface structurally and chemically, to understand the nature of sorption occurring when a trace organic contaminant is present in aqueous effluents. Pentachlorophenol (PCP) was the trace contaminant used in the experiments. Scanning electron microscopy (SEM), mercury porosimetry, Fourier transform infrared spectroscopy (FTIR) and X‐ray photoelectron spectroscopy (XPS) were the techniques used, in addition to classical chemical analysis and solid phase micro extraction (SPME) prior to gas chromatography with mass spectrometry (GC‐MS) for PCP quantification. The pine bark proved to be a material of very low porosity, low specific surface area, strong carbon aromatic content probably relative to polyphenols and lignin composition. Sorption experiments showed a good correlation for the linear adsorption isotherm, as well as the desorption experiments. In the conditions tested, the average PCP removal after 24 h was above 98 per cent. This material proved to be an encouraging sorbent for cheap water remediation solutions.

Alumina-Supported Noble Metal Catalysts for Destructive Oxidation of Organic Pollutants in Effluent from a Softwood Kraft Pulp Mill

The effectiveness of alumina-supported noble metal catalysts for the destructive oxidation of organic pollutants in effluent from a softwood kraft pulp mill was evaluated in a slurry reactor at 463 K and an oxygen pressure of 1.5 MPa. The effects of catalyst preparation procedures, such as metal loading, calcination, or reduction treatment on the catalytic activities, were also tested. Alumina-supported palladium catalysts were found to be more effective than supported manganese, iron, or platinum catalysts. The rate of oxidation over Pd/alumina catalyst was significantly higher than that of the uncatalyzed reaction. Adding Ce on the alumina support was found to promote the activity of alumina-supported Pt catalyst but inhibit the activity of alumina-supported Pd catalyst. The reaction mechanisms for the catalytic wet oxidation process and the roles of Ce on catalytic activity for destructive oxidation of organic pollutants in wastewater are discussed.