Removal Of P-nitrophenol Research Articles

Preparation and evaluation of iron oxide/hydrotalcite intercalated with dodecylsulfate/β-cyclodextrin magnetic organocomposite for phenolic compounds removal

The magnetic adsorbent iron oxide-hydrotalcite modified with the surfactant dodecylsulfate (DS) and β-cyclodextrin (β-CD) was evaluated in the removal of phenol (PHE), p-nitrophenol (PNP) and p-cresol (PCS) from aqueous solution. The magnetic adsorbent was named Fe/HT-DS/β-CD and has the advantage of being easily removed from aqueous solution through application of a magnetic field. The adsorbent was characterized by Infrared Spectroscopy (IR), X-ray diffractometry (XRD), Raman spectroscopy, Scanning Electron Microscopy (SEM), Energy Dispersion Spectroscopy (EDS), Atomic Absorption Spectroscopy (AAS), zeta potential and elemental analysis (CHNS). The effect of pH, dosage, contact time, kinetics, temperature and adsorption thermodynamics were evaluated by phenolic compounds removal. The maximum adsorption capacity of the PHE, PNP and PCS by the adsorbent were 216.08 mg g−1, 255.63 mg g−1 and 272.48 mg g−1, respectively, at 180 min, pH 6 and 25 °C. The thermodynamic parameters indicate that the adsorption is spontaneous and endothermic. This adsorbent showed satisfactory results when applied in the treatment of pulp and paper industry effluent that naturally contains phenol, p-nitrophenol and p-cresol and fortified river water samples.

New insights into the reinforced reduction performance of Fe0/C internal electrolysis activated by persulfate for p-nitrophenol removal

In this study, the reduction of iron-carbon internal electrolysis was reinforced by persulfate for p-nitrophenol removal. The effects of persulfate dosage, initial pH and iron-carbon mass ratio were comprehensively studied in batch experiments. In the system of iron-carbon internal electrolysis coupled with persulfate, the iron-carbon internal electrolysis and persulfate had a significant mutual influence, exhibiting a wide range of pH in the treatment process. Moreover, the coupled system also showed the remarkable removal and degradation efficiency of p-nitrophenol according to the contrast experiments. The satisfactory results should be attributed to the potential reduction of iron-carbon internal electrolysis, which was stimulated by persulfate to transform the nitro group to the amine group, accompanying the subsequent oxidation. Furthermore, persulfate possessed the ability that the dynamically destructive effect on external and internal of Fe0 and the scavenging action on activated carbon, effectively strengthening the potential energy for release and transfer of reductive substances. Both HO• and SO4•− as the main free radicals were formed to mineralize the intermediates in the coupled system. These findings indicate that the system of iron-carbon internal electrolysis coupled with persulfate can be a promising strategy for the treatment of the toxic and refractory wastewater.

P-Nitrophenol -Bioremediation using potent Pseudomonas strain from the textile dye industry effluent

p-Nitrophenol (PNP) occurs as industrial waste effluents for many industries, including dye & textile and tannery industry, and is the cause of severe health risk to human as well as ecological ones. The limitations of PNP degradation and their pathway remains limited for Indian subcontinent (Eastern India side), climatic and demographic difference from rest of India and the rest of the world. The main aim of the evaluation was to see the efficacy of the isolated strain (Pseudomonas sp JB163) for removal of PNP. Optimisation of temperature and pH for the best growth of bacterial strain performed, and then degradation efficiency was checked. The isolate obtained based on 16 srRNA was closely related to Pseudomonas sp showed PNP degradation of more than 90 % up to PNP range of 85 ppm. Optimum temperature & pH for the bacteria to survive was found to be 30 °C & 8.5(slightly alkaline pH). There are many studies throughout the world, which has done phenolic biodegradation using isolated bacteria. However, there are not many studies reported from the eastern part of the Indian subcontinent. Our results suggested that Pseudomonas sp JB163 strain would be a suitable aspirant for bioremediation of nitro-phenolic compounds contaminated sites in the environment on a bigger concentrated scale.

Preparation and characterisation of nanokaolinite photocatalyst for removal of P-nitrophenol under UV irradiation

Preparation and characterisation of nanokaolinite photocatalyst for removal of P-nitrophenol under UV irradiation

N/Ti3+ co-doping biphasic TiO2/Bi2WO6 heterojunctions: Hydrothermal fabrication and sonophotocatalytic degradation of organic pollutants

This study describes the one-step in situ hydrothermal construction of N/Ti3+ co-doping biphasic TiO2/Bi2WO6 heterojunctions (NT-TBWx) and investigates their sonophotocatalytic degradation of organic contaminants in water. The obtained samples are characterized in detail including X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and Ultraviolet diffuse reflectance spectroscopy, etc. Their photocatalytic, sonocatalytic, and sonophotocatalytic performance are compared by the degradation of organic pollutants and found the degradation rate according to the order: photocatalysis < sonocatalysis < sonophotocatalysis. In addition, NT-TBWx samples present better sonophotocatalytic activity for the removal of methylene blue (MB), p-Nitrophenol, Rhodamine B, and levofloxacin compared with that of NT-TiO2 and pure TiO2. Especially, the highest sonophotocatalytic degradation rate is demonstrated for NT-TBW1. Additionally, the excellent stability of NT-TBWx samples is demonstrated by four cycles of sonophotocatalytic measurements with a tiny decline. Superoxide radical (·O2−) is found to dominate the sonophotocatalytic degradation process of MB. The synergic effect among the doping level, heterophase junction, and heterojunctions as well as between sonocatalysis and photocatalysis contribute to superior sonophotocatalytic activity. This work provides a new alternative architecture of TiO2-based nanomaterials and promotes their application in environmental issues.

Role of radical and non-radical pathway in activating persulfate for degradation of p-nitrophenol by sulfur-doped ordered mesoporous carbon

A new application of heteroatom doped ordered mesoporous carbon as metal-free catalyst was proposed in this study. Sulfur-doped ordered mesoporous carbons (S-OMCs) with different sulfur doping amount were synthesized to activate persulfate (PS) for p-nitrophenol (PNP) degradation. Thereinto, the activation effect of 2.0 wt% S-OMC improved most significantly after it reached the adsorption equilibrium, and the removal rate of PNP was 82.02%. The optimal experimental effect can be achieved at room temperature and unadjusted pH (pH = 6), retrenching energy and chemical input for practical applications. Higher temperatures could cause radical quenching, while electrostatic repulsion existed between S-OMC and PNP at pH > 6.03, which led to a reduction of PNP removal. Moreover, the structural features and surface characters of S-OMC were studied and found that the defect structure and surface functional groups had noticeable influence on the reusability of S-OMC. More importantly, both radical activation and non-radical activation were detected, and non-radical activation predominated in the S-OMC/PS system. The radical pathway oxidized pollutant by generating OH, SO4−, and O2−. Among them, OH was dominated. While the non-radical pathway attacked contaminant by continuous electron transport between PNP, S-OMC and PS. This research provided a new perspective on the application of heteroatom doped ordered mesoporous carbon and presented an easy and effectual way for the removal of organic contaminants.

Heterogeneous co-activation of peroxymonosulfate by CuCoFe calcined layered double hydroxides and ultraviolet irradiation for the efficient removal of p-nitrophenol

Advanced oxidation processes by the activation of peroxymonosulfate (PMS) have been widely concerned for the enhanced degradation of organic pollutants. In this work, CuCoFe calcined layered double hydroxides (CuCoFe-CLDH) were successfully prepared via a simple method, and its lamellar structure and spinel-like composites were proved by using XRD, SEM and FT-IR. The CuCoFe-CLDH was used to activate PMS to produce many active species for the degradation of p-nitrophenol (PNP) under ultraviolet irradiation (UV). At the optimal conditions of CuCoFe-CLDH dosage 0.3 g/L and PMS dosage 0.3 g/L, it was discovered that the degradation efficiency of 20 mg/L PNP was about 95.11% under UV light within 30 min. In addition, the degraded reaction accorded with the pseudo-first-order kinetic behaviors, and it was found that SO 4 ·− and ·OH radicals were effective active species in the quenching experiments under the CuCoFe-CLDH/UV/PMS system. The CuCoFe-CLDH could still keep above 93% after five continuous recycles, and also showed remarkable reusability and stability in accord with the characterization analysis of fresh and used materials. Briefly, this work could be a promising method for the treatment of the phenol-bearing wastewater and support theoretical foundation for PMS activation.

Catalytic degradation of p-nitrophenol by magnetically recoverable Fe3O4 as a persulfate activator under microwave irradiation

In this study, Fe3O4 and microwave (MW) were combined to activate persulfate (PS) for the removal of organic matter, resulting in the enhanced degradation of p-nitrophenol (PNP) in solution. During the preparation of Fe3O4, the effect of sodium acetate was examined, and the results showed that the concentration of sodium acetate had little effect on the catalytic activity of the Fe3O4/PS/MW system but did have an effect on the Fe3O4 yield. In addition, with regards to the representative environmental factors, the degradation experiment showed that humic acid and the co-existing anions of chloride, sulfate, nitrate, and phosphate had little effects on p-nitrophenol removal; however, carbonate had a negative effect. In addition, the Fe3O4/PS/MW system performed well in the initial pH range of 3.0–9.0. According to the quenching experiment and electron paramagnetic resonance (EPR) detection, sulfate radicals and a minority of hydroxyl radicals play dominant roles in the degradation process. In addition, the role of Fe3O4 was confirmed to take part in the degradation process by X-ray photoelectron spectroscopy (XPS) analysis. Because of the good performance observed in the water matrices of tap water and the Songhua River, these results demonstrate the potential application of the Fe3O4/PS/MW system for wastewater treatment.

Pre-magnetized Fe0 as heterogeneous electro-Fenton catalyst for the degradation of p-nitrophenol at neutral pH

Pre-magnetized Fe0 (Pre-Fe0) was for the first time applied as heterogeneous catalyst to enhance the oxidation efficiency of electro-Fenton (EF) for the degradation of p-nitrophenol (PNP). The parameters including current, initial pH and pre-Fe0 dosage of Pre-Fe0/EF process were optimized and compared with other two processes (conventional Fe0/EF and electro-oxidation) to confirm its advantage. The rate constants of PNP removal were 1.40–3.82 folds of those by Fe0/EF process under various experimental conditions. The application of pre-Fe0 as catalyst could extend the working pH range from 3.0 to neutral conditions for PNP removal and reduce the Fe0 dosage from 2 to 0.5 mM corresponding to Fe0/EF, avoiding the second pollution of iron sludge. The superiority of Pre-Fe0/EF process was also verified to improve the degradation and mineralization of other phenols and antibiotics. Furthermore, a possible pathway of PNP degradation was revealed by the identification of intermediates and organic acids, and the possible mechanism of pre-Fe0 efficiently enhanced the EF efficiency was proposed. This work demonstrated that such a novel heterogeneous EF process using pre-Fe0 catalyst was clean and promising for the degradation of refractory organic pollutants.

Carbon-Intercalated 0D/2D Hybrid of Hematite Quantum Dots/Graphitic Carbon Nitride Nanosheets as Superior Catalyst for Advanced Oxidation.

Efficient charge separation and sufficiently exposed active sites are important for light-driving Fenton catalysts. 0D/2D hybrids, especially quantum dots (QDs)/nanosheets (NSs), offer a better opportunity for improving photo-Fenton activity due to their high charge mobility and more catalytic sites, which is highly desirable but remains a great challenge. Herein, a 0D hematite quantum dots/2D ultrathin g-C3 N4 nanosheets hybrid (Fe2 O3 QDs/g-C3 N4 NS) is developed via a facile chemical reaction and subsequent low-temperature calcination. As expected, the specially designed 0D/2D structure shows remarkable catalytic performance toward the removal of p-nitrophenol. By virtue of large surface area, adequate active sites, and strong interfacial coupling, the 0D Fe2 O3 QDs/2D g-C3 N4 nanosheets establish efficient charge transport paths by local in-plane carbon species, expediting the separation and transfer of electron/hole pairs. Simultaneously, highly efficient charge mobility can lead to continuous and fast Fe(III)/Fe(II) conversion, promoting a cooperative effect between the photocatalysis and chemical activation of H2 O2 . The developed carbon-intercalated 0D/2D hybrid provides a new insight in developing heterogeneous catalysis for a large variety of photoelectronic applications, not limited in photo-Fenton catalysis.

Flow synthesis of a novel zirconium-based UiO-66 nanofiltration membrane and its performance in the removal of p-nitrophenol from water

In this work, a thin zirconium-based UiO-66 membrane was successfully prepared on an alumina hollow fiber tube by flow synthesis, and was used in an attempt to remove p-nitrophenol from water through a nanofiltration process. Two main factors, including flow rate and synthesis time, were investigated to optimize the conditions for membrane growth. Under optimal synthesis conditions, a thin UiO-66 membrane of approximately 2 μm in thickness was fabricated at a flow rate of 4 mL·h-1 for 30 h. The p-nitrophenol rejection rate for the as-prepared UiO-66 membrane applied in the removal of p-nitrophenol from water was only 78.1% due to the existence of membrane defects caused by coordinative defects during membrane formation. Post-synthetic modification of the UiO-66 membrane was carried out using organic linkers with the same flow approach to further improve the nanofiltration performance. The result showed that the p-nitrophenol rejection for the postmodified membrane was greatly improved and reached over 95%. Moreover, the post-modified UiO-66 membrane exhibited remarkable long-term operational stability, which is vital for practical application.

Ozonation process intensification of p-nitrophenol by in situ separation of hydroxyl radical scavengers and microbubbles.

The ozonation efficiency for removal of recalcitrant organic pollutants in alkaline wastewater is always low because of the presence of some hydroxyl radical scavengers. To solve this problem, the O3/Ca(OH)2 system was put forward, and p-nitrophenol (PNP) was chosen to explore the mechanism of this system. The effects of key operational parameters were studied respectively; the Ca(OH)2 dosage 3 g/L, ozone inlet flow rate 3.5 L/min, ozone concentration 65 mg/L, reactor pressure 0.25 MPa, and temperature 25 °C were obtained as the optimal operating conditions. After 60 min treatment, the organic matter mineralized completely, which was higher than the sum of the ozonation-alone process (55.63%) and the Ca(OH)2 process (3.53%). It suggests that the calcium hydroxide in the O3/Ca(OH)2 process possessed a paramount role in the removal of PNP. The liquid samples and the precipitated substances were analyzed by gas chromatography mass spectrometry, X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy; it was demonstrated that Ca(OH)2 could accelerate the generation of hydroxyl radical and simultaneously in situ separate partial intermediate products and CO3 2- ions through some precipitation reactions.

Corn husk derived magnetized activated carbon for the removal of phenol and para-nitrophenol from aqueous solution: Interaction mechanism, insights on adsorbent characteristics, and isothermal, kinetic and thermodynamic properties

In this study, waste corn husk was used for the synthesis of an effective adsorbent (cornhusk activated carbon, CHAC) and by treating at two different temperatures, 250 °C (CHAC-250) and 500 °C (CHAC-500) to check adsorption efficiency. The synthesized adsorbents were characterized with the help of scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy, Particle size analysis and x-ray diffraction (XRD), which revealed the different properties of the two adsorbents. The synthesized adsorbents were applied for the removal of phenol and p-nitrophenol (PNP) from aqueous solution. CHAC-500 was more efficient than the CHAC-250. The maximum adsorptions of phenol and PNP by CHAC-500 were ∼96% and ∼94%, respectively, while the maximum adsorptions of phenol and PNP by CHAC-250 were ∼81% and ∼84%, respectively. The adsorption processes were best fitted with the Langmuir adsorption isotherm and the pseudo-second-order kinetic model. The adsorption of phenol was an exothermic process, while that of PNP was an endothermic process, on both adsorbents.

Characterization and adsorption performance of graphene oxide - montmorillonite nanocomposite for the simultaneous removal of Pb2+ and p-nitrophenol.

Montmorillonite-graphene oxide composite (MGC) with their own advantages was successfully fabricated for the simultaneous treatment of the combined pollution wastewater containing heavy metal ions and organic pollutants. The features of MGC were analyzed by X-ray diffraction, transmission electron microscopy, atomic force microscopy and Fourier transform infrared spectroscopy. Subsequently, a series of batch experiments were carried out to investigate the adsorption performance of Pb2+ and p-nitrophenol (PNP) onto MGC in single and binary system. The results indicated that MGC exhibited a gossamer layer with spots and a larger interlayer spacing. In single adsorption experiment, the removal of PNP by MGC reached 96.82%, while Pb2+ removal reached 98.94%, which was maintained at the same level as montmorillonite. In binary acidic system of Pb2+ and PNP, the removal of Pb2+ reached 98.23%, while PNP removal dropped to 51.06% due to their competitive adsorption. The thermodynamic study indicated that the chemisorption was predominant in the adsorption of Pb2+ onto MGC, while physisorption was for PNP. It was exactly that the strong competitiveness of Pb2+ brought the remarkable reduction in PNP adsorption capacity in the simultaneous adsorption.

Efficient removal of p-nitrophenol from water using montmorillonite clay: insights into the adsorption mechanism, process optimization, and regeneration.

The present research highlights the use of a montmorillonite clay to remove p-nitrophenol (PNP) from aqueous solution. The montmorillonite clay was characterized using powder X-ray diffraction, Fourier-transformed infrared spectroscopy, scanning electron microscopy, X-ray fluorescence, Brunauer-Emmett-Teller analyses, and zero point charge in order to establish the adsorption behavior-properties relationship. The physiochemical parameters like pH, initial PNP concentration, and adsorbent dose as well as their binary interaction effects on the PNP adsorption yield were statistically optimized using response surface methodology. As a result, 99.5% removal of PNP was obtained under the optimal conditions of pH 2, adsorbent dose of 2 g/l, and PNP concentration of 20 mg/l. The interaction between adsorbent dose and initial concentration was the most influencing interaction on the PNP removal efficiency. The mass transfer of PNP at the solution/adsorbent interface was described using pseudo-first-order and intraparticle diffusion. Langmuir isotherm well fitted the experimental equilibrium data with a satisfactory maximum adsorption capacity of 122.09 mg/g. The PNP adsorption process was thermodynamically spontaneous and endothermic. The regeneration study showed that the montmorillonite clay exhibited an excellent recycling capability. Overall, the montmorillonite clay is very attractive as an efficient, low-cost, eco-friendly, and recyclable adsorbent for the remediation of hazardous phenolic compounds in industrial effluents.

Highly Salt Resistant Polymer Supported Ionic Liquid Adsorbent for Ultrahigh Capacity Removal of p-Nitrophenol from Water

The exploration of new adsorbents is still highly desirable, especially those with ultrahigh adsorption capacity, super anti-interference ability, and excellent regeneration power. Herein, a novel chloromethyl polystyrene resin supported task-specific ionic liquid adsorbent was prepared by chemical grafting and its performance to remove p-nitrophenol (PNP) from water was systematically investigated by both batch process and dynamic column elution method. It was shown that the adsorbent not only exhibited excellent adsorption performance toward high concentration PNP with an ultrahigh adsorption capacity of 1269.8 mg/g within 30 min but also could effectively remove trace PNP from water at the concentration as low as 0.0025 mg/L. Common interfering ions and neutral molecules in water, especially K+, Na+, Ca2+, Mg2+, NO3–, and Cl–, did not interfere with the removal of PNP even if their concentrations (1 mol/L) were 1 000 000 times higher than that of PNP, which indicates its potential in removal of PNP fro...

Quantitative and Qualitative Characterization of Pure Copper Chromite Nanocomposites for Photodegradation of p-Nitrophenol in Aqueous Medium

A series of copper chromite samples with different Cu/Cr molar ratios (0.5, 0.6, 0.7, 0.8, 0.9, 1, and 2) have been synthesized using the citric acid complexation sol–gel method from Cu(NO3)2·3H2O and Cr(NO3)3·9H2O precursor salts. The amounts of Cr2O3 and CuO in the samples were qualitatively and quantitatively confirmed by titration, and the samples were fully characterized using various common techniques such as x-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), energy-dispersive x-ray (EDAX) spectroscopy, transmission electron microscopy, and Fourier-transform infrared (FT-IR) spectroscopy. The XRD spectra of the samples showed the presence of CuCr2O4 and CuO as major and minor phase, respectively. SEM analysis determined the morphology of the samples to be spherical or quasispherical with low degree of homogeneity, while the presence of Cu, Cr, and O atoms was proved by EDAX without other impurity elements. FT-IR spectroscopy demonstrated the presence of Cu–O or Cr–O bonds in the range of 400 cm−1 to 700 cm−1. The photocatalytic activity of the as-prepared samples was tested in removal of p-nitrophenol from aqueous solution. The results showed that the sample with Cu/Cr = 0.6 exhibited the highest photodegradation percentage (and also degradation rate) during 100 min of light exposure.

Carboxymethyl sago pulp/chitosan hydrogel as an immobilization medium for activated sludge for p‐nitrophenol biodegradation

ABSTRACTIn this study, carboxymethyl sago pulp (CMSP) derived from sago waste was successfully crosslinked with ferric ions in the presence of chitosan forming a novel immobilization matrix for p‐nitrophenol (PNP)‐acclimated activated sludge. On the basis of the shortest biodegradation time of PNP, the optimized operational conditions of immobilization were found to be: 7 w/v% CMSP, 9 g L−1 of activated sludge, 0.1 M ferric ion, and 15 min of crosslinking time. Observable inhibited PNP biodegradation was exhibited by the suspended activated sludge at the initial PNP concentration of 400 mg L−1. In contrast, complete mineralization was achieved by the CMSP/chitosan‐immobilized activated sludge (CMSP/Ch‐AS) beads. The results revealed the important role of CMSP/Ch hydrogel in protecting activated sludge from the toxicity of PNP. The CMSP/Ch‐AS beads could be reused consecutively up to three and two cycles, respectively, for the biodegradation of PNP at 200 and 400 mg L−1, with the attainment of more than 99% of PNP removal at each cycle. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47531.

A new MOFs/polymer hybrid membrane: MIL-68(Al)/PVDF, fabrication and application in high-efficient removal of p-nitrophenol and methylene blue

MOFs/polymer hybrid membranes combine the special surface activity of MOFs and the excellent carries nature of porous polymer and thus exhibit unexpected adsorption/separation performances in the solid-phase extraction. In this paper, a new kind of MOFs/polymer composite membrane, MIL-68(Al)/PVDF have been fabricated for the first time through blending the MIL-68(Al) nanoparticles and polyvinylidene fluoride (PVDF) casting solution and following the lyotropic phase transition. Some means such as SEM, XRD and FT-IR are used to character the structure of these hybrid membranes. The membrane performances including the hydrophilic/hydrophobic properties, membrane porosity and membrane water flux are also measured. The effects of doping amount of MIL-68(Al) on the structure and performances of MIL-68(Al)/PVDF hybrid membranes are discussed. Two persistent organic pollutants: p-nitrophenol (PNP) and methylene blue (MB) are chosen as main adsorption objects to evaluate the adsorption activity of MIL-68(Al)/PVDF hybrid membranes. The influences of various conditions on the adsorption activities are investigated in detail and the optimum adsorption conditions are determined. All the MIL-68(Al)/PVDF hybrid membranes exhibit enhanced adsorption capacity compared to pristine PVDF, and the adsorption activities of hybrid membranes are promoted continually with the increasing doping contents of MIL-68(Al). The adsorption thermodynamics analysis indicates that the adsorption process is mainly characterized by Langmuir monolayer adsorption and chemical adsorption. The coordination bonding formed between NO2 of PNP and Al(III) of MIL-68(Al), and the acid-base interaction between the sulfur of MB and Al(III) of MIL-68(Al) may be responsible to the highest removal efficiency of PNP and MB. The good dynamics adsorption and regeneration performances indicate the prospect applications of these MOFs/PVDF hybrid membranes in the separation of organic contaminants from industrial waste water.

Preparation and characterization of nanokaolinite photocatalyst for removal of P-nitrophenol under UV irradiation

A nanokaolinite photocatalyst was prepared successfully using intercalating method which depends on insertion of chemical reagent between bulk kaolinite layers followed by delamination process. The as-prepared nanokaolinite photocatalysts were characterised by X-ray diffraction, FTIR analysis, transmission electron microscope (TEM) and UV-vis diffuse reflectance spectroscopy. XRD data show that the crystals size of exfoliated nanokaolinite in the range ~26-32 nm. FTIR peaks assign to presence of nitrogen between nanokaolinite layers, which may be lead to decrease the band gap of prepared samples. The photocatalytic activity of nanokaolinite photocatalysts was investigated by degradation of PNP under ultra-violet irradiation. The ideal nanokaolinite sample (K/urea) show extraordinary photocatalytic activity (100%) toward PNP within 30 min. due to its enhanced band gap value.