Hydrodynamic Cavitation Enhanced SR-Aops Degradation of Organic Pollutants in Water:A Review

SR-AOP(sulfate radical advanced oxidation process)is a novel water treatment method able to eliminate refractory organic pollutants.Hydrodynamic cavitation(HC)is a novel green technology,that can effectively produce strong oxidizing sulfate radicals.This paper presents a comprehensive review of the research advancements in these fields and a critical discussion of the principal factors influencing HC-enhanced SR-AOP and the mechanisms of synergistic degradation.Furthermore,some insights into the industrial application of HC/PS are also provided.Current research shows that this technology is feasible at the laboratory stage,but its application on larger scales requires further understanding and exploration.In this review,some attention is also paid to the design of the hydrodynamic cavitation reactor and the related operating parameters.

Genotoxicity evaluation and a primary risk assessment of organic pollutants in the drinking water sources of Nanjing, China

An increasing number of industrial, agricultural, and commercial chemicals in the aquatic environment leads to various deleterious effects on organisms, which is becoming an increasingly serious problem in China. In this study, the comet assay was conducted to investigate the genotoxicity to human body caused by organic concentrates in the drinking water sources of Nanjing City from Yangtze River of China, and health and ecology risk due to expose to these organic pollutants were evaluated with the multimedia environmental assessment system （MEAS）. For all the water samples, they were collected from four different locations in the drinking water sourcr samples, es of Nanjing City. The results of the comet assay showed that all the organic concentrates from the water samples could induce different levels DNA damages on human peripheral blood lymphocytes, and a statistically significant difference （p〈0.01） was observed compared with the solvent control, which demonstrated the genotoxicity was in existence. According to the ambient severity （AS） of individual compound, we had sorted out the main organic pollutants in the drinking water source of the four waterworks, and the results showed that there was some potential hazard to human body for all the source water, namely the total ambient severity （TAS） of health for each water source was more than 1. However, the TAS of ecology for each water source was less than 1, which indicated that it was safe to ecology. The results of this investigation demonstrate the application of the comet assay and the MEAS in aquatic environmental monitoring studies, and the comet assay found to be fast, sensitive, and suitable for genotoxicity monitoring programs of drinking water source.

Removal of Nitrogen, Phosphorus, and Organic Pollutants From Water Using Seeding Type Immobilized Microorganisms

Objective To study the possibility of removing nitrogen, phosphorus, and organic pollutants using seeding type immobilized microorganisms. Methods Lakes P and M in Wuhan were chosen as the objects to study the removal of nitrogen, phosphorus, and organic pollutants with the seeding type immobilized microorganisms. Correlations between the quantity of heterotrophic bacteria and the total nitrogen （TN）, total phosphorus （TP）, and total organic carbon （TOC） in the two lakes were studied. The dominant bacteria were detected, inoculated to the sludge and acclimated by increasing nitrogen, phosphorus and decreasing carbon source in an intermittent, time-controlled and fixed-quantity way. The bacteria were then used to prepare the seeding type immobilized microorganisms, selecting diatomite as the adsorbent cartier. The ability and influence factors of removing nitrogen, phosphorus, and organic pollutant from water samples by the seeding type immobilized microorganisms were studied. Results The coefficients of the heterotrophic bacterial quantity correlated with TOC, TP, and TN were 0.9143, 0.8229, 0.7954 in Lake P and 0.9168, 0.7187, 0.6022 in Lake M. Ten strains of dominant heterotrophic bacteria belonging to Pseudomonas, Coccus, Aeromonas, Bacillus, and Enterobateriaceae, separately, were isolated. The appropriate conditions for the seeding type immobilized microorgansims in purifying the water sample were exposure time=24 h, pH=7.0-8.0, and quantity of the immobilized microorganisms=0.75-1g/50 mL. The removal rates of TOC, TP, and TN under the above conditions were 80.2%, 81.6%, and 86.8%, respectively. Conclusion The amount of heterotrophic bacteria in the two lakes was correlated with TOC, TP, and TN. These bacteria could be acclimatized and prepared for the immobilized microorganisms which could effectively remove nitrogen, phosphorus, and mixed organic pollutants in the water sample.

Uptake and translocation of organic pollutants in plants:A review

Organic pollutants, such as polychlorinated dJbenzo-p-dioxins and polychlofinated dibenzofurans （PCDD/Fs）, polychlodnated biphenyls （PCBs）, antibiotics, herbicides, and bisphenol A （BPA）, are commonly found in agricultural environments. They are released into the environment as a result of their use for human health purposes and farm management activities, and are often discharged as waste-water effluents. Most of these organic pollutants are taken up by plants through roots and leaves, and when they enter the tissue, they cause serious damage to the plants. Although the toxicity of organic pollutants to plants, especially to plant cells, has been intensively studied, a systematic review of these studies is lacking. Here we review researches on the toxicity of organic pollutants, their uptake, and translocation in plants. Our objective is to assemble existing knowledge concerning the interaction of organic pollutants with plants, which should be useful for the development of plant-based systems for removing pollutants from aquatic and agricultural environments.

Modified g-C_(3)N_(4) derived from ionic liquid and urea for promoting visible-light photodegradation of organic pollutants

In this work,modified g-C_(3)N_(4) was fabricated successfully by calcination of ionic liquid(IL) and urea.The addition of IL changed the polymerization mode of urea,induced the self-assembly of urea molecules,modified the morphological structure of the tightly packed g-C_(3)N_(4),and extended the electron conjugation system.When using 1-butyl-3-methylimidazolium chloride([Bmim]Cl) as a modifier,the heteroatom Cl could be inserted into the g-C_(3)N_(4) to optimize the electronic structure.The results of characterizations indicate that the unique structure of modified g-C_(3)N_(4) has an expanded electron delocalization range,introduces an interlayer charge transmission channel,promotes the charge transmission,reduces the band gap,enhances the absorption of visible light,and inhibits electron-hole recombination.Modified g-C_(3)N_(4) showed excellent photocatalytic performance for the degradation of rhodamine B and tetracycline.Furthermore,the effect of different anions in 1-butyl-3-methylimidazolium salts([Bmim]Cl,[Bmim]Br,[Bmim][BF_(4)],and [Bmim][PF_6]) on the structure and function of g-C_(3) N_(4) are discussed.

Persistent organic pollutants control strategy in China

The development of Persistent Organic Pollutants(POPs) control policy in China in the context of international concerns on POPs was reviewed. The aspects of the Chinese POPs control strategies were analyzed, and compared with those of developed counterparts (e.g. US, EU, Japan). Currently, while the legal framework on POPs management, which complies with international guidelines has been established, it should be improved in the areas of special POPs management, risk assessment, the precautionary principle, life-cycle management and technical support capacity. The analysis of Chinese POPs policy and suggestions for strengthening the science-based decision making capacity are not only useful for Chinese decision-makers, but also a case study for developing world and make a great contribution for the global elimination of POPs to make a toxic-free future.

REMOVAL OF ORGANIC POLLUTANTS USING TITANIUM DIOXIDE MEDIATED PHOTOCATALYTIC OXIDATION

A simple and effective method of removing polluted organics in water is reported here.Titanium dioxide is a catalyst in photo-oxidation of monocrotophos.The mechanism of photocatalytic oxidation and the kinetics of the reaction were studied. This same principle also leads to the construction of instrument of PTR-FIA analysis for monitoring organic phosphorus and phosphate in water.

Distribution of persistent organic pollutants in aggregate fractions of a temperate forest and semi-rural soil

The fate of persistent organic pollutants (POPs) and their interactions with aggregates of forest soils are not completely understood. Our objectives here were to quantify the distribution of different POPs in water-stable aggregate fractions and to study their influence on soil organic carbon (Corg) content. Soil samples were taken from a forest-site, Gogerddan (G) and a semi-rural site, Hazelrigg (H) in Great Britain, from 0-2 and 2-5?cm and 0-4 and 8-12?cm soil depth, respectively. POPs analyzed were PAHs, PCBs, total DDT, PBDEs and HCB. The bulk soil analysis showed that the concentration of POPs was significantly higher (p?≤?0.05) in forest site G than in semi-rural site H, particularly at the surface soil levels compared to the subsurface soil depths in both sites. Total concentrations of PCBs and PAHs of both sites were positively correlated with Corg contents. POPs concentrations and Corg, Nt contents of forest site G were significantly higher (p?≤?0.05) in water-stable macro aggregates (>0.25, >1, >2?mm) than the micro aggregates (>0.053?mm). The POP concentrations of all aggregate fractions after normalizing to their respective Corg content were increased due higher contamination and strong sorption by Corg. These results showed a strong effect of Corg on the partitioning of organic pollutants to soil aggregate size fractions. The present study affirms the ecological significance of forest soils act as a potential sink of POPs. In summary, our results suggest that aggregate fractions may promote soil C storage and act as a potential POP sink in surface soil without increasing their concentration in the aggregate fraction of subsoil.

Exploration of Nonlinear Modeling Techniques to Predict the Retention Time of Organic Pollutants in Natural Water and Wastewater

Water pollution affects plants and organisms living in these bodies of water; and, in almost all cases the effect is damaging not only to individual species and populations, but also to the natural biological communities. Genetic algorithm and kernel partial least square （GA-KPLS） and Levenberg- Marquardt artificial neural network （L-M ANN） techniques were used to investigate the correlation between retention time （tR） and descriptors for 150 organic contaminants in natural water and wastewater, which are obtained by gas chromatography coupled to high-resolution time-of-flight mass spectrometry （GC-TOF MS）. The L-M ANN model gave a significantly better performance than the GA-KPLS model. This indicates that L-M ANN can be used as an alternative modeling toot for quantitative structure-retention relationship （QSRR） studies.

Study on Migration and Transformation Rule of Organic Pollutants (COD) in Aerated Zone

Collecting waste water with a certain c onc entration of organic pollutants COD (chemical oxygen demand), static adsorption, static biodegradation and dynamic soil column experiments were made in laborato ry, we researched migration and transformation of COD in aerated zone, and put f orward a mathematical model showing the process. The results show that adsorptio n of organism in aerated zone is linear, which is represented by Henry's law s =K dc+s d, adsorption coefficient K d=0.069 3; biodegradati on diagram accord basically with first order kinetics equation c=c 0e -K 1t , biodegradation coefficient K 1 = 0.049 9 d -1 ; dispersio n coefficient D= 0.002 42 m 2/d in experiments. The migration and transform ation of organic pollutants (COD) in aerated zone jointly result from many f actors such as dispersion, adsorption and biodegradation etc..

Seasonal Variation and Removal of Organic Pollutants in Wastewater Using Low-Cost Treatment Technologies in Tamale Metropolis, Ghana

The use of wastewater as alternative source of water for vegetable crop irrigation has become an eminent component of urban agriculture due to current global water crises in most developing countries, and admits the increasing effects of global climate change. The practise is however noted to be associated with significant health and environment risk due to excessive pollutant load. The study assessed the level of seasonal variation and removal of organic pollutants in wastewater using gravel filters combined with stabilisation ponds at Zagyuri in the Tamale Metropolis. The yard scale experiment consisted of cylindrical containers of different length filled with six different sizes of filter media and connected to stabilisation ponds where wastewater is allowed to pass through for filtration and stabilisation. The results indicated that for both seasons, the average concentration of BOD released into the stream at Zagyuri was 92.98 mg/l and 103.54 mg/l for the dry and wet season respectively whilst the COD was averaged 132.78 mg/l and 143.75 mg/l for the dry and wet seasons respectively. The results of the simple linear regression revealed a strong positive linear relationship between BOD and COD with coefficient of determination (R2) of 0.873 which was statistically highly significantly at Pr value of <0.0001. The results for ANOVA for the treatment factor were statistically highly significant at Pr values of 0.0011 and <0.0001 respectively for BOD5 and COD. The average concentration of BOD was higher than the Ghana EPA recommended levels while that of COD was lower and thus within safety range for discharge into the environment.

Analysis and Evaluation of Uncertainty in the Determination of Organic Pollutants

[Objectives]To determine the content of organic pollutants by CALUX bioassay.[Methods]According to JJF 1059.1-2012 Technical Specification for Evaluation and Expression of Uncertainty in Measurement,the determination results of organic pollutants were analyzed,various sources of uncertainty that may be introduced in the detection process were analyzed,and the mathematical model of uncertainty was established.Type A and B evaluation methods were used to calculate the components of uncertainty and extended uncertainty.[Results]In the range of 95%confidence interval,the determination result of organic pollutants was 6.59 pg/g fat,and the extended uncertainty was 0.0764 pg/g fat,so the determination results of organic pollutants could be expressed as(6.59±0.0764)pg/g fat(k=2).[Conclusions]This study can provide a basis for more accurate determination of organic pollutants.

Sources and Trends of Persistent Organic Pollutants at Three Passive Monitoring Sites in South Africa

The Stockholm Convention on Persistent Organic Pollutants (SCPOPs) is an international treaty that operates under the patronage of the United Nations (UN) to control certain chemicals that are considered persistent organic pollutants (POPs). They are of great concern because of their adverse effects on human health and the environment. Exposure to POPs may lead to cancer, infertility, respiratory infections, and other health complications. It is therefore critical to study the degree of human and environmental exposure to these POPs. Passive air sampling was conducted in South Africa to evaluate the presence and trends of persistent organic pollutants at Barberspan (rural agricultural), Vanderbijl Park (urban industrial) and Molopo Nature Reserve (isolated nature reserve). Samples were collected in 2012. Passive air samplers using poly were used for sampling. The Buchi System B-811 automatic extractor was used to analyze for dichloro-diphenyl-trichlorethane (DDT), pentachlorobenzene (PeCB), hexechlorobenzene (HCB) polychlorinated biphenyls (PCBs) and hexachlorocyclohexane (HCH). Sampling was conducted for a period of one year. POPs concentrations were generally low at all sites, but Vanderbijl Park had the highest concentrations. Seasonal changes in concentrations were much the same at the three sites with temperatures and wind patterns being major factors. The presence of these chemicals in Molopo Nature Reserve and Barberspan is evidence of long range transportation over dry semi desert areas. Back-trajectories indicate possible sources, including areas where DDT is used for malaria control. The presence of POPs is areas they have never been in use poses health and environmental risks in these areas.

Research Progress and Challenges on Persistent Organic Pollutants in Lakes

Lakes are the main reservoirs of persistent organic pollutants(POPs)from land,atmo sphere and rivers.POPs in lakes undergo complex exchange,transformation,and degradation between water-air-sediment-biota interfaces,which are constrained and regulated by various physical,chemical and biological factors.POPs can affect ecological conditions,chemical properties of water and sedi ments,and biodiversity of the lake system.Therefore,it is important to study the sources,migration,transformation,environmental behavior and ecological impacts of POPs in lake ecosystems.This re view summarizes research progress on detection technologies,diversity and origins,historical records,migration and transformation,distribution patterns,degradation and toxic effects of POPs in lakes.Fi nally,future directions related to POPs in lakes were summarized.

N-doping offering higher photodegradation performance of dissolved black carbon for organic pollutants: experimental and theoretical studies

We investigated the influence mechanism of N-doping for dissolved black carbon(DBC)photodegradation of organic pollutants.The degradation performance of N-doped dissolved black carbon(NDBC)for tetracycline(TC)(71%)is better than that for methylene blue(MB)(28%)under irradiation.These levels are both better than DBC degradation performances for TC(68%)and MB(18%)under irradiation.Reactive species quenching experiments suggest that h and-O,are the main reactive species for NDBC photodegraded TC,while-OH and h*are the main reactive species for NDBC photodegraded MB.-OH is not observed during DBC photodegradation of MB.This is likely because N-doping increases valence-band(VB)energy from 1.55 eV in DBC to 2.04 eV in NDBC;the latter is strong enough to oxidize water to form-OH.Additionally,N-doping increases the DBC band gap of 2.29 to 2.62 eV in NDBC,resulting in a higher separation efficiency of photo-generated electrons-holes in NDBC than in DBC.AIl these factors give NDBC stronger photodegradation performance for TC and MB than DBC.High-performance liquid chromatography-mass spectrometry(HPLC-MS)characterization and toxicity evaluation with the quantitative structure-activity relationship(QSAR)method suggest that TC photodegradation intermediates produced by NDBC have less aromatic structure and are less toxic than those produced by DBC.We adopted a theoretical approach to clarify the relationship between the surface groups of NDBC and the photoactive species produced.Our results add to the understanding of the photochemical behavior of NDBC.

Nanoscaled MnSnO_(2)@CsPbBr_(3) quantum dots heterostructure photocatalyst as efficient organic pollutants degradation by peroxymonosulfate;DFT calculation

In this work,we developed a promising photocatalyst in CsPbBr_(3) quantum dots(QDs)because of their exceptional optoelectronic characteristics.However,QDs applications in the field of photocatalysis were mainly hampered by their poor stability and insufficient charge transfer efficiency.Herein,a novel and efficient MnSnO_(2)@CsPbBr_(3)(MSO@QDs)nanocomposite was first time effectively designed and synthe-sized by a wet impregnation method for peroxymonosulfate(PMS)activation under the light.The newly generated interface phase of QDs between MnSnO_(2)(MSO)showed great potential to improve light ab-sorption,leading to effective separation and transfer of photoelectron-hole pairs.This novel nanocompos-ite MSO@QDs showed great Flurbiprofen(FL)removal efficiency under the PMS/Light system.It should be noted that this nanocomposite removed 85.74%of FL in just 70 min,which was almost 1.11 and 2.51 times greater than using pure QDs and pure MSO,respectively.Based on thorough measurements of structural analysis,Brunauer-Emmett-Teller(BET),UV-vis spectra,electrochemical impedance spec-troscopy(EIS),transient photocurrent response,and a potential mechanism for organic pollutants degra-dation over MSO@QDs nanocomposite was envisioned.The principal reactive species of photoinduced holes(h^(+)),i.e.O_(2)^(˙−),SO_(4)^(˙−),^(˙)OH,and non-radical(^(1)O_(2))were characterized via scavengers’technique and electron paramagnetic resonance(EPR)measurements.The highest photocatalytic performance for the re-moval of MO,MB,and IBU was demonstrated by MSO@QDs nanocomposite/PMS,revealing their excellent ability to remove organic pollutants through photo-oxidation.Furthermore,the developed nanocompos-ite exhibited good stability in an aqueous medium.According to computational investigation using the density functional theory(DFT)method,the site’s higher Fukui index f^(0) value corresponds to a greater propensity to be attacked by reactive species.This work offers a fresh perspective on developing further high-efficiency,low-cost photocatalysts for wastewater treatment.

Spray deposited yttrium incorporated TiO_(2) photoelectrode for efficient photoelectrocatalytic degradation of organic pollutants

This work presents result on yttrium-doped titanium dioxide(YTO) thin films using a cost-effective spray pyrolysis technique for the photoelectrocatalytic degradation of phthalic acid(PA) and benzoic acid(BA).The physicochemical properties of YTO thin films were studied using X-ray diffraction,Raman spectroscopy,X-ray photoelectron spectroscopy,field-emission scanning electron microscopy,UV-vis spectroscopy,etc.The obtained results confirm the presence of yttrium in the host lattice.The band bending and flat band positions were studied using Mott-Schottky analysis.The film with 1% doping amount shows the highest degradation efficiency for both the model pollutants compared to TiO_(2).The stability of 1% YTO film confirms excellent performance analyzed by recycling tests using a UV-vis spectrophotometer.These results highlight the significance of rare earth metal doping in TiO_(2)for improved photoelectrocatalytic degradation efficiency.

An Allochroic Molecular Cage Switch for Sensing and Capturing Organic Pollutants

The adsorption method is considered to be one of the most promising organic pollutants emission reduction strategies.The design and synthesis of high-performance porous adsorbents are one of the most important but challenging works.In this work,we constructed a new class of porous molecular cage switches by a simple reaction using phenolphthalein as the raw material.The molecular cage switches displayed interesting on-off behavior towards organic guests,which is highly responding to organic pollutants with rapid color change and is also able to adsorb these organic pollutants through an open-to-close pathway.This molecular cage switch also has excellent regenerative cycling properties and water resistance,which is expected to be employed in the handling of organic pollutants in the future.

Modification strategies on 2D Ni-Fe MOF-based catalysts in peroxydisulfate activation for efficient organic pollutant removal

This study reports several modification strategies to optimize and enhance the performance of twodimensional(2D) metal organic frameworks(MOFs)-derived catalysts in peroxydisulfate(PDS) activation.The raw 2D Ni-MOF and 2D Ni-Fe-MOF without modification show poor catalytic activities for PDS activation and high metal ion leaching. The carbonization of 2D MOF can increase the activity of the catalyst but cannot solve the metal leaching problem. The further acid treatment of carbonization products can further improve the catalytic activity and decrease the metal ion leaching. The in-situ growth of2D MOF on graphene oxide(GO) support with subsequent carbonization and acid treatment offers the best performance in PDS activation for organic pollutant removal with low metal ion leaching. Compared with other PDS systems, the Ni-Fe-C-acid/GO system displays much lower catalyst and PDS dosages for p-chloroaniline degradation. This study presents new insights in the modification strategies of 2D MOFbased catalysts in PDS activation.