Degradation Of Personal Care Products Research Articles

Efficiently photocatalysis activation of peroxydisulfate by Fe-doped g-C3N5 for pharmaceuticals and personal care products degradation

Peroxydisulfate (PDS) based advanced oxidation processes (AOPs) are widely used for the degradation of pharmaceutical and personal care products (PPCP) in wastewater treatment. In this study, a Fe-doped g-C3N5 (Fe@g-C3N5) was synthesized as a photocatalyst for catalyzing the PDS-based AOPs to degrade tetracycline hydrochloride (TH) at pH 3 and Naproxen (NPX) at pH 7. The photocatalytic performance of Fe@g-C3N5 was 19% and 67% higher than g-C3N5 and g-C3N4 for degradation of TH at pH 3, respectively, while it was 21% and 35% at pH 7. The Fe:N ratio in Fe@g-C3N5, was calculated as 1:3.79, indicating that the doped Fe atom formed a FeN4 structure with an adjacent two-layer graphite structure of g-C3N5, which improved the charge separation capacity of g-C3N5 and act as a new reaction center that can efficiently combine and catalyze the PDS to radicals. Although the intrinsic photo-degradation performance is weak, the photocatalytic performance of Fe@g-C3N5 has great room for the improvement and application in wastewater treatment.

Developing a UV dosing strategy for UV/chlorine process towards the trade-off between pharmaceuticals and personal care products degradation and disinfection by-products formation

In addition to UV wavelength and pH, UV irradiation intensity and fluence also play crucial roles in the UV/chlorine treatment of drinking water. This work aimed to develop a novel UV irradiation strategy to achieve a trade-off between pharmaceuticals and personal care products (PPCPs) degradation and disinfection by-products (DBPs) formation during UV/chlorine water treatment under a specific chlorine dose. Under high UV irradiation intensity at the same UV fluence, the faster chlorine photolysis produced higher steady-state concentrations of •Cl and •OH species but abated cumulative exposures of free available chlorine (CTFAC = ∫0t[Cl2]dt). As a result, the degradation rate of PPCPs was accelerated, but the removal percentage of some PPCPs decreased. Meanwhile, the degradation of the chromophores of dissolved organic matters (DOM) declined by 23.3%–24.8% under the higher UV irradiation intensity. Reducing CTFAC values (50.7%–57.6%) by high UV irradiation intensity could mitigate the formation of haloacetic acids, trihalomethanes and absorbable organic halogens (13.9%–14.9%), which addressed the key role of active chlorine in the formation of DBPs in the UV/chlorine process. DBPs were mainly generated from the interactions of DOM with reactive chlorine. The Vibrio fischeri data further indicated that increasing UV intensity reduced acute toxicity regardless of UV wavelength or water pH. For the same UV fluence dose, the high UV irradiation intensity can effectively control the trade-off between oxidation efficiency and DBPs formation during UV/chlorine treatment.

Step Scheme Fe2o3/S Doped G-C3n4 Heterojunction Photocatalysts for Photo-Fenton Pharmaceuticals and Personal Care Products Degradation

Step Scheme Fe2o3/S Doped G-C3n4 Heterojunction Photocatalysts for Photo-Fenton Pharmaceuticals and Personal Care Products Degradation

Surface Engineering and Built‐In Electric Field within Copper Sulfide/Graphitic Carbon Nitride Photocatalyst for Extremely Enhanced Charge Separation and Broad‐Spectrum Pharmaceuticals and Personal Care Products Degradation

Semiconductor photocatalysis is the most commonly used technology for the photocatalytic degradation of pharmaceuticals and personal care products, but it suffers from fast charge recombination and a low degradation efficiency. Herein, a novel photocatalyst is synthesized by anchoring copper sulfide nanoparticles on oxygen‐doped graphitic carbon nitride hollow nanospheres. g‐C3N4 is bent to form a nanosphere structure, which promotes the interlayer photogenerated charge transfer, improves the specific surface area, and provides more reaction sites. Moreover, the hollow structure can enhance the utilization of light through the reflection and refraction of light in the cavity. The hollow nanospheres structure has a large number of reaction sites and enhanced light absorption due to internal reflection. After the introduction of copper sulfide, a built‐in electric field is formed, which improves the separation and transmission of photogenerated carriers, and extends the light response range into the near‐infrared (NIR) region. Consequently, the photocatalytic degradation efficiency of phenol and diclofenac reach 100% after vis–NIR irradiation for only 25 and 30 min, respectively. The radical trapping experiments and electron spin resonance analysis show that •O2− plays an important role in the photodegradation process. This work provides a strategy for constructing broad‐spectrum response photocatalysts.

Removal of personal care products (PCPs) from greywater using a submerged membrane bioreactor (SMBR): The effect of hydraulic retention time

The rising trend of depletion in global water supplies and the consistent accumulation of emerging environmental contaminants in water, soil and plant have become an international concern during the past decade. In recent years, the removal of personal care products (PCPs) from greywater has inspired a great attention for facile water recycling. In this study, the performance of a specially designed submerged membrane bioreactor (SMBR) system toward high-efficiency degradation of PCPs released through household greywater was investigated. The influent PCP-rich greywater was prepared by mixing commercial PCPs and the SMBR operated under different hydraulic retention time (HRT) values for 150 days of continuous operation. The results revealed that HRT has a striking influence on the treatment performance of the SMBR for PCP contaminants while the SMBR displayed a superior degradation capability for all categories of PCP contaminants (including antimicrobial agent, preservative, fragrance and UV Filter) at the effluent stream. Triclosan, methylparaben and propylparaben as the contaminants with the highest concentration at prepared PCP-rich greywater were removed up to 98.20%, 99.96% and 99.97%, respectively and other ones had more than 64% removal efficiency at HRT of 16 h. The chemical oxygen demand (COD) and biological oxygen demand (BOD) at the optimum HRT value were negligible.

Nanoscale zero valent iron-activated persulfate coupled with Fenton oxidation process for typical pharmaceuticals and personal care products degradation

In this study, a two-staged nanoscale zero valent iron-activated persulfate coupled with Fenton (nZVI-PS-Fenton) oxidation process is applied to remove typical pharmaceuticals and personal care products (PPCPs) from water. Due to the partial substitution of PS by cheaper H2O2, the main advantage of the combined treatment is to reduce the cost of oxidation reagent and reduce sulfate release in water. Experiment results indicated that sulfamethazine (50 mg L−1) is degraded up to 96% within 30 min using 2 mM nZVI, 1 mM PS and 0.5 mM H2O2. Thanks to the acidifying effect of persulfate addition for degradation of PPCPs and reduction of pH value in the first stage, the Fenton reaction could further finalize sulfamethazine degradation independently from initial pH. The degradation of PPCPs obeyed pseudo-first-order reaction kinetics. The effect of organic and inorganic radical scavengers naturally present in water was studied: results indicated that they actually have an inhibition effect, but this is perceivable at rather high concentrations. Nine typical PPCPs (i.e., bisphenol A, indomethacin, norfloxacin, tetracycline, paracetamol, carbamazepine, phenacetin, sulfamethoxazole and sulfamethazine) were significantly degraded (77–100%), suggesting that the proposed nZVI-PS-Fenton process can be applied to remove such kind of pollutants from (waste) water streams and prevent their spread into the environment.

Advances in photo-catalysis approach for the removal of toxic personal care product in aqueous environment

Removal of personal care products (PCPs) has become one of the challenging aspects around the globe. From the last few decades, it has been introduced as one of the emerging pollutants to the environment that affects directly or indirectly our ecosystem mainly aqueous environment. From biodegradation to photo-degradation mechanism, there are different categories of treatment methods, while the priority is based upon being cheaper, effective, reliable, environmental and economically friendly that should be compatible to water chemistry. Currently, photo-catalysis is considered as one of the most reliable and efficient non-conservative technologies for the degradation of PCPs industrial effluents from the aqueous environment. A recent development of photo-catalysis technology for the removal of PCPs gives efficient performance by using carbonaceous TiO2 composites. By using hybrid nature of photo-catalyst, one can achieve suitably high and attractive efficiency with comparable low cost. In this review article, the different photo-catalysis mechanism while moving from non-photo-catalysis to photo-catalysis approach and its practical application for the removal efficiency of various polluting agents have been discussed. A critical evaluation on the various parameters for this approach is highlighted. Future perspective refers to the need for coupling of different semiconducting nano-materials with photo-catalysis that could yield higher efficiency than those of previous one. This facilitates further insight into photo-catalysis approach for the efficient degradation of PCPs to ensure healthy aqueous environment, and some points regarding fate of PCPs should be discussed in future perspective.

Oxidative degradation of the antibiotic oxytetracycline by Cu@Fe3O4 core-shell nanoparticles

A core-shell nanostructure composed of zero-valent Cu (core) and Fe3O4 (shell) (Cu@Fe3O4) was prepared by a simple reduction method and was evaluated for the degradation of oxytetracycline (OTC), an antibiotic. The Cu core and the Fe3O4 shell were verified by X-ray diffractometry (XRD) and transmission electron microscopy. The optimal molar ratio of [Cu]/[Fe] (1/1) in Cu@Fe3O4 created an outstanding synergic effect, leading to >99% OTC degradation as well as H2O2 decomposition within 10min at the reaction conditions of 1g/L Cu@Fe3O4, 20mg/L OTC, 20mM H2O2, and pH3.0 (and even at pH9.0). The OTC degradation rate by Cu@Fe3O4 was higher than obtained using single nanoparticle of Cu or Fe3O4. The results of the study using radical scavengers showed that OH is the major reactive oxygen species contributing to the OTC degradation. Finally, good stability, reusability, and magnetic separation were obtained with approximately 97% OTC degradation and no notable change in XRD patterns after the Cu@Fe3O4 catalyst was reused five times. These results demonstrate that Cu@Fe3O4 is a novel prospective candidate for the pharmaceutical and personal care products degradation in the aqueous phase.

Application of nanoscale zero valent iron and iron powder during sludge anaerobic digestion: Impact on methane yield and pharmaceutical and personal care products degradation

Lab scale and single stage high solid anaerobic digestion of sewage sludge spiked with freshly synthesized nanoscale zero valent iron (nZVI) and commercial iron powder (IP) under mesophilic condition (37±1°C) was performed. The effects of both additives on methane yield, and pharmaceutical and personal care product (PPCP) removal were investigated. Results showed that methane yield was increased by 25.2% and 40.8% in the presence of nZVI (0.1%) and IP (1.6%), respectively. Removal efficiencies of chemical oxygen demand were 54.4% and 66.2% in the presence of nZVI and IP, respectively, which were higher compared to the control group (44.6%). In addition, most PPCPs could be partly or completely removed during the anaerobic digestion process. The application of nZVI and IP showed positive impact on the removal of chlorinated PPCPs (p<0.05), but did not show significant impact on other PPCPs (p>0.05). Our finding suggests that the application of nZVI and IP in anaerobic digestion could be a promising way to enhance methane yield but had less improvement on PPCP degradation.

Microbial degradation of personal care products

Microbial degradation of personal care products

Microbial degradation of personal care products

Microbial degradation of personal care products