Organic Removal Efficiency Research Articles

Bacterial dynamics and functions driven by bulking agents to enhance organic degradation in food waste in-situ rapid biological reduction (IRBR).

This study investigated the effects of different bulking agents (i.e., sawdust, wheat straw, rice straw, and corncob) on bacterial structure and functions for organic degradation during food waste in-situ rapid biological reduction (IRBR) inoculated with microbial agent. Results showed that the highest organic degradation (409.5g/kg total solid) and volatile solids removal efficiency (41.0%) were achieved when wheat straw was used, largely because the degradation of readily degradable substrates and cellulose was promoted by this bulking agent. Compared with other three bulking agents, the utilization of wheat straw was conducive to construct a more suitable environmental condition (moisture content of 18.0-28.2%, pH of 4.91-5.87) for organic degradation during IRBR process, by virtue of its excellent structural and physiochemical properties. Microbial community analysis suggested that the high-moisture environment in rice straw treatment promoted the growth of Staphylococcus and inhibited the activity of the inoculum. By contrast, lowest bacterial richness was observed in corncob treatment due to the faster water loss. Compared with these two bulking agents, sawdust and wheat straw treatment led to a more stable bacterial community structure, and the inoculated Bacillus gradually became the dominant genus (36.6-57.8%) in wheat straw treatment. Predicted metagenomics analysis showed that wheat straw treatment exhibited the highest carbohydrate metabolism activity which improved the pyruvate, amino sugar and nucleotide sugar metabolism, and thereby promoted the organic degradation and humic substrate production. These results indicated that wheat straw was a more desirable bulking agent, and revealed the potential microbial organics degradation mechanism in IRBR process.

Meso-thermophilic acidogenic biotreatment of mixed wastewater from toilets and coffeeshop: Effect of temperature on the efficiency of organic removal and VFA productions

Meso-thermophilic acidogenic biotreatment of mixed wastewater from toilets and coffeeshop: Effect of temperature on the efficiency of organic removal and VFA productions

A comprehensive study on the treatment of various organic pollutants by NiCoFe layered double oxide: Material synthesis and characterization, decomposition mechanism exploration, and real water applications

In this report, we successfully synthesized NiCoFe layered double oxide (NiCoFe-LDO) by heating a hydrothermally prepared NiCoFe layered double hydroxide in the air at 400–700 °C. The morphology, crystal structure, surface area, elemental composition and environment, functional groups, thermal stability, and magnetic properties of the materials were determined by SEM, XRD, BET, XPS, FTIR, TGA-DTG, EPR, and VSM analyses. The material was then used to activate potassium peroxymonosulfate (PMS) for degrading Rhodamine B (RhB) and other dyes in different conditions of water, surface water, and wastewater. The results showed that NiCoFe-LDO annealed at 500 °C can remove 97.86% RhB (20 mg/L) in 14 min at pH 7. Moreover, the presence of anions (i.e., HPO4-, HCO3–, CO32–, NO3–, Cl-, and SO42-) in the solution affected the RhB removal efficiency. In various dyes removal tests, the removal efficiency of the dyes was in the order of RhB > OG > DB71 ≈ MO ≈ TTZ ≈ JGB ≈ MB. In the radical scavenging tests, the occurrence and role of radicals in RhB decomposition were in the order of O2●- >1O2 > SO4●- > HO●, thus the decomposition of RhB is based on both radical and non-radical reactions. Moreover, the intermediates formed during the reaction were detected. Accordingly, the mechanism of RhB decomposition by the NiCoFe-LDO under PMS activation was proposed. Finally, the durability of the materials and its high dyes and organics removal efficiency in both surface water and actual wastewater suggests a great potential for practical applications of NiCoFe-LDO/PMS in wastewater treatment, especially for the recalcitrant components.

Enhanced degradation and biogas production of waste activated sludge by a high-solid anaerobic membrane bioreactor together with in pipe thermal pretreatment process

An integrated system combining in pipe thermal pretreatment with a high-solid anaerobic membrane bioreactor (AnMBR) was developed to promote the anaerobic digestion of waste activated sludge (WAS). Two different pretreatment methods investigated were the venturi nozzle treatment (VNT) and steam injector treatment (SIT), both at a low temperature of 70 °C. The biogas production after pretreatment was 23.5–30.5% higher than that of untreated WAS, and the VS based biogas yield was 0.46–0.47 L/g-VS when HRT was 15 days. The membrane operated smoothly when the average flux was 9.6 and 4.5 L/m2/h under an MLTS of 25 and 30 g/L, respectively. The calculations of the mass balance indicated that 44–45% COD was converted to methane with pretreatment and only 1% remained in the permeate. That is, high energy recovery and organic matter removal efficiency were achieved for the treatment of WAS using the high-solid AnMBR with in pipe thermal pretreatment.

Degradation of gemfibrozil in aqueous solutions by gas–liquid dielectric barrier discharge plasma combined with CNTs/γFe2O3

AbstractThe degradation effects and mechanism on gemfibrozil (GEM) in aqueous solution by dielectric barrier discharge (DBD) plasma combined with the catalyst CNTs/γFe2O3 are investigated. The concentrations of plasma‐generated reactive species, including H2O2, O3, , and OH, are measured with spectrophotometric and fluorescent probes. The effects of the plasma treatment period, discharge power, initial GEM concentration, solution pH value, conductivity, and the catalytic property are studied on the degradation rate and energy efficiency. Compared with the sole plasma treatment, CNTs/γFe2O3 could maximally improve the GEM degradation rate and energy efficiency to 99.7% ± 0.2% and 76.5 ± 5.2 mg·kW−1·h−1, respectively. The solution's total organic carbon removal efficiency has been increased to 47.2% ± 2.7%. Meanwhile, the possible degradation pathways of the plasma‐treated GEM solution and overall biological toxicity of GEM degradation intermediates and residual catalyst in solution are investigated.

Split dosing of H2O2 for enhancing recalcitrant organics removal from landfill leachate in the Fe0/H2O2 process: Degradation efficiency and mechanism

This study applied a simple but efficient hydrogen peroxide (H2O2) split-dosing strategy as part of a zero valent iron (Fe0)/H2O2 process to effectively remove refractory organics from landfill leachate. Results showed that both the traditional Fenton and Fe0/H2O2 processes produced comparable treatment results, but the Fe0/H2O2 process (advantageously) produced much less sludge. Furthermore, Fe0/H2O2 process using a split H2O2 dosing strategy removed refractory organics from landfill leachate better than using the same oxidant dosage in a single dose. Under optimized operating conditions (H2O2 dosage = 12 mL/L) that included four small sub-doses of H2O2, removal efficiencies of total organic carbon, light absorbance at 254 nm, and color number were 56.76%, 58.59% and 94.56%, respectively. In addition, humic-like substances as refractory organics in the leachate were almost completely removed by the improved Fe0/H2O2 process. Our results demonstrated that the split-dosing strategy substantially enhanced hydroxyl radical (•OH) production in the Fe0/H2O2 process. Overall, the catalytic mechanism of the unique Fe0/H2O2 process can be assigned to the homogeneous catalytic effect of Fe2+ from Fe0 leaching and the heterogenous catalytic effect of iron (hydro) oxides, both of which act on H2O2 to produce •OH. This study provides an efficient strategy that can enhance refractory organics removal efficiency for practical application of the Fe0/H2O2 process.

Operational performance of corncobs/sawdust biofilters coupled to microbial fuel cells treating domestic wastewater

Biofilters coupled to microbial fuel cells (MFCs) are the most integral treatment technology that generate water-energy nexus for rural zones sanitation. Moreover, biofilters coupled to MFCs, using organic residues as bed filter have not been studied. Therefore, the aim of this study was comparatively to evaluate biofilters based on corncobs/sawdust coupled to MFCs treating domestic wastewater. Biofilters based on corncobs/sawdust (50%, v/v) as bed filter incorporating microorganisms (BM), earthworms/microorganisms (BEM, Eisenia foetida Savigny), plants/microorganisms (BPM, Canna indica L.), and all organisms (HB) were evaluated. These biofilters were coupled to 2 electrochemical systems based on graphite cathodes with graphite (G)/stainless-steel mesh (M) anodes. Three nominal hydraulic loading rates (0.3, 0.5, and 1 m3 m−2 d−1) evaluating removal of organic matter, nutrients and pathogens were monitored. Voltage within electrochemical systems also were registered. Results demonstrated that biofilters based on corncob/wood chips coupled to MFCs reach mean organic matter removal efficiencies over 80% (COD: 86%, BOD5: 91%). Nevertheless, HBG was the most efficient (up to 6%) biofiltration technology monitored. The biofiltration typologies studied reported removal efficiencies of nutrients (NH3-N, PO43−) and pathogens (fecal coliforms) up to 99%. Specifically, BMG and HBG were the biofiltration typologies that registered the highest energy recovery (up to 104 mV, 29 mW m−2). Within all the biofiltration typologies studied, the hybrid biofiltration coupled to MFCs using graphite (HBG) is the one that offers the best water-energy nexus conditions, thanks to its biological complexity.

Operational and biochemical aspects of co-digestion (co-AD) from sugarcane vinasse, filter cake, and deacetylation liquor.

This work performed co-AD from the vinasse and filter cake (from 1G ethanol production) and deacetylation liquor (from the pretreatment of sugarcane straw for 2G ethanol production) in a semi-Continuous Stirred Tank Reactor (s-CSTR) aiming to provide optimum operational parameters for continuous CH4 production. Using filter cake as co-substrate may allow the reactor to operate throughout the year, as it is available in the sugarcane off-season, unlike vinasse. A comparison was made from the microbial community of the seed sludge and the reactor sludge when CH4 production stabilized. Lactate, butyrate, and propionate fermentation routes were denoted at the start-up of the s-CSTR, characterizing the acidogenic phase: the oxidation-reduction potential (ORP) values ranged from -800 to -100 mV. Once the methanogenesis was initiated, alkalizing addition was no longer needed as its demand by the microorganisms was supplied by the alkali characteristics of the deacetylation liquor. The gradual increase of the applied organic load rates (OLR) allowed stabilization of the methanogenesis from 3.20 gVS L-1 day-1: the highest CH4 yield (230 mLNCH4 g-1VS) and average organic matter removal efficiency (83% ± 13) was achieved at ORL of 4.16 gVS L-1 day-1. The microbial community changed along with the reactor operation, presenting different metabolic routes mainly due to the used lignocellulosic substrates. Bacteria from the syntrophic acetate oxidation (SAO) process coupled to hydrogenotrophic methanogenesis were predominant (~ 90% Methanoculleus) during the CH4 production stability. The overall results are useful as preliminary drivers in terms of visualizing the co-AD process in a sugarcane biorefinery integrated to scale. KEY POINTS: • Integration of 1G2G sugarcane ethanol biorefinery from co-digestion of its residues. • Biogas production from vinasse, filter cake, and deacetylation liquor in a semi-CSTR. • Lignocellulosic substrates affected the biochemical routes and microbial community. • Biomol confirmed the establishment of the thermophilic community from mesophilic sludge.

Mechanism study of CoS2/Fe(III)/peroxymonosulfate catalysis system: The vital role of sulfur vacancies

Peroxymonosulfate (PMS) activation methods have attractive advantages in advanced oxidation process (AOPs) due to their powerful ability of directly or indirectly generating various reactive oxygen species (ROS). Herein, trace amount of Fe(III) ions were added into the commercial-CoS2/PMS system to improve the CoS2/PMS decomposition for organics removal. The organics removal efficiency could reach >90% towards methylene blue (MB), diclofenac sodium (DCF), sulfamethoxazole (SMX) and bisphenol A (BPA) in the CoS2/Fe(III)/PMS system, with the kinetic apparent rate constant kobs of 0.141, 0.206, 0.247 and 0.091 min−1, respectively. The synergistic effect between Fe(III) ions and sulfur-vacancies on CoS2 for PMS degradation were revealed for the first time in cobalt sulfides/PMS system. Quenching experiments and ESR analysis proved that 1O2 was the major ROS and was produced mainly by the hydrolysis of SO5•–. Besides, the high degradation efficiency was obtained by the contribution of SO4•– and •OH. Electron spin–resonance spectroscopy (ESR), cyclic voltammetry (CV) and Raman spectrum data revealed that the addition of Fe(III) ions could optimize the intensity of sulfur vacancies on the CoS2 surface, which hindered the PMS reduction ability of Co(II), but accelerated the PMS oxidation to form 1O2. The degradation path of MB was analyzed by liquid chromatograph-mass spectrometer (LC-MS). The mechanism studies speculated that the sulfur vacancies of CoS2 provided the binding sites for Fe(III) ions with Co(II), which facilitated the PMS activation by Co(III).

Enhanced removal of Cu-EDTA in a three-dimensional electrolysis system with highly graphitic activated biochar produced via acidic and K2FeO4 treatment

Herein, we report a novel strategy for the fabrication of almond shell biochar-based materials containing highly dispersed graphene nanosheet structures by sequential treatment with hydrochloric acid and potassium ferrate. The resulting material serving as particle electrodes endowed the three-dimensional electrolysis system with excellent and stable Cu-ethylene diamine tetraacetic acid (Cu-EDTA) decomplexation and mineralization ability, along with Cu(Ⅱ), chemical oxygen demand, and dissolved total organic carbon removal efficiencies of 96.8%, 92.5%, and 86.2%, respectively. In contrast to excess Cu(Ⅱ) or EDTA, the complete complexation between Cu(Ⅱ) and EDTA facilitated EDTA degradation. During the reaction, the adsorption toward Cu(Ⅱ), rather than EDTA, in the complexing system, alleviated the burden of electrochemical oxidation for Cu-EDTA decomplexation. This, together with direct and indirect electrocatalytic oxidation mediated by adsorbed hydroxyl radicals on the particle electrode surface, contributed to the enhanced removal of Cu-EDTA. Density functional theory calculations further demonstrated the main types of active sites and the importance of the graphene nanosheet structure of the particle electrodes. This work provides different perspectives on the electrocatalytic removal of heavy metal complexes.

Aqueous phase reforming of distiller's grain derived biogas Plant wastewater over α-MoO3 nanosheets

A novel method which combines aqueous phase reforming (APR) and activated carbon adsorption (ACA) was proposed to treat the distiller's grain derived biogas plant wastewater (DGBW). APR was performed over α-MoO3 nanosheets with oxygen vacancies (α-MNOV), Pt/C and Ni/α-MNOV catalysts under temperature of 225 °C and residence time of 30 min. An optimal yield of 4.91 mLhydrogen/mLDGBW was obtained over α-MNOV, which also exhibited the highest organic pollutants removal efficiency. After APR over α-MNOV and following ACA, the removal efficiencies of non-purgeable organic carbon (NPOC), chemical oxygen demand (COD) and total nitrogen (TN) reached 79.45%, 87.82% and 44.78%, respectively. The significant performance of α-MNOV could be attributed to two aspects: shorter van der Waals (vdW) heterostructures presented α-MNOV which enhanced the hydrogen generation process, and the abundant oxygen vacancies (OVs) in α-MNOV which increased its stability and lattice oxygen generation capability, facilitating the decomposition of the organics during APR.

Insights to improve covered lagoon biodigesters through by-products recovery in pig farms

Pig farming activity has an important role in the Brazilian economy and generates effluents with a high polluting potential. The covered lagoon biodigester is a simple and suitable alternative for the treatment of swine manure. This work aimed to propose improvements to the pig effluent treatment system composed by covered lagoon biodigesters. Therefore, a survey of a typical plant configuration of pig effluent treatment was accomplished and alternatives were suggested in order to get a greater energy sustainability in farms through resource recovery. The proposed interventions were based on studies of scientific papers, technical equipment manuals, technical research and consultation with professionals of the field. The optimization of the systems operation considers some criteria, such as: (i) need for solids removal; (ii) organic loading; (iii) operation temperature; (iv) effluent recirculation; and (v) biogas energy recovery. Firstly, a typical scenario was identified without any improvements, in which the biogas is sent to flares without energy recovery. Subsequently, systems improvement insights were proposed, mainly regarding effluent heating through a solar heating system or by recovering the thermal energy from biogas and biogas recovering. The treatment optimization would increase the efficiency of organic matter removal and biogas production, as well as electric energy production and reduction in greenhouse gases emissions. The use of tools such as Life Cycle Analysis (LCA) can favor decision making and comparing proposed alternatives.

High efficiency of simultaneous nitrification, denitrification, and organics removal in the real-scale treatment of high C/N ratio food-processing wastewater using micro-aerobic reactors

Micro-aerobic reactors (MARs) play an important role in simultaneous nitrification, denitrification, and organics removal but are affected by the C/N ratio. In this study, high C/N ratio food-processing wastewater was treated using two-step MARs. The average removal efficiencies of total nitrogen and chemical oxygen demand during the MAR process were 84.21% and 95.43%, respectively. The efficiency of simultaneous nitrification and denitrification was 88.87% and 17.26% in MAR-1 and MAR-2, respectively; simultaneously, organic matter was efficiently degraded. Protein-like materials were biodegraded preferentially, and the degree of change in fulvic-like substances was the greatest during the MAR processes. This was attributed to the spatial distribution of the dissolved oxygen concentration in a single MAR, which may influence the microbial community composition (e.g., that of Nitrospira) and the regulation of gene functions.

Removal performance and membrane fouling mitigation mechanism of electrocoagulation membrane dissolved ozone flotation

To enhance the removal of wastewater treatment plant effluent organic matter, the electrocoagulation membrane dissolved ozone flotation (EMDOF) method for simultaneous filtration and in-situ cleaning (SFC) was established. EMDOF exhibited better dissolved organic matters (DOM) removal efficiency than the electrocoagulation-membrane (ECM) and ozonation-membrane (OM) processes. Under optimal operating conditions, i.e. current density 10 mA/cm2 and ozone aeration rate of 200 mL/min, EMDOF achieved dissolved organic carbon (DOC), UV254, and color removal efficiencies of 35.22%, 71.48%, 69.44%, respectively, within 990 min. The turbidity of the EMDOF effluent stabilized at 0 NTU. The normalized flux (J/J0) of EMDOF was lower than that of OM under the same ozone dosage, but higher than that of ECM under the same current density. SFC removed the sludge from the membrane surface and better eliminated the reversible membrane fouling. The J/J0 restored by SFC reached 90% of the preliminary stage and stabilized at 63% in the later stages. Scanning electron microscopy and particle size distributions showed that larger flocs and more porous cake layers formed with EMDOF than with ECM, resulting in superior membrane fouling mitigation.

Enhancing the performance of thermophilic anaerobic digestion of food waste by introducing a hybrid anaerobic membrane bioreactor

The thermophilic anaerobic digestion of food waste was a long-term challenge for maintaining process stability. A hybrid submerged anaerobic membrane bioreactor (AnMBR), integrating 27%(v/v) polyurethane sponge as fixed carriers were therefore investigated at (50 ± 2) °C. The organics removal efficiencies, COD mass balance, and membrane filtration performance were investigated in a 75-days continuously operated experiment. The results showed that methane production reached 0.31 L/(kg·COD) under an organic loading rate of 7.3 kg·COD/(m3·d). The low concentration of total volatile fatty acids of 247 ~ 274 mg/L and a high proportion of Methanosarcina (>97%) represented the high stability of the thermophilic process. Approximately 21% of biomass grew on the carriers in the hybrid AnMBR and induced a much lower suspended solids concentration and viscosity of bulk sludge. Noticeable lower trans-membrane pressure was consequently observed. The affecting factors identified by PCA analysis proved the advantages of the hybrid AnMBR for alleviating membrane fouling formation.

Insights into the electro-hybrid ozonation-coagulation process–Significance of connection configurations and electrode types

The electro-hybrid ozonation-coagulation process (E-HOC) integrates electrocoagulation (EC) and ozonation simultaneously in a single unit. Nevertheless, the performance of the EC process is highly dependent on the polar connection configuration (monopolar vs. bipolar connection) and the type of generated coagulants (single-coagulant vs. dual-coagulants). In this study, the removal efficiency of the E-HOC process with different connection configurations and types of coagulants was assessed. The E-HOC process with bipolar connection (BE-HOC) exhibited higher removal efficiency for wastewater treatment plant (WWTP) effluent organic matter and ibuprofen (IBP) compared with the E-HOC process with monopolar connection (ME-HOC). Furthermore, dual-coagulant generation (released from both Al and Fe electrodes) in the BE-HOC process greatly improved the WWTP effluent organic matter and IBP removal efficiency. Lower energy consumption was observed for the BE-HOC process compared with the ME-HOC process. It was found that ozonation promoted the polymerization reactions during coagulant hydrolyzis in the E-HOC process. Compared with the ME-HOC process, the BE-HOC configuration and dual-coagulant mode further facilitated polymeric hydrolyzed coagulant species formation, thereby improving ozone catalytic and coagulation performance. According to trapping experiments and EPR analysis, •OH formation was enhanced in the BE-HOC process and dual-coagulant mode. In addition, more active reaction sites of generated hydrolyzed coagulant species were observed with bipolar connection and in the dual-coagulant generation mode based on X-ray photoelectron spectroscopy (XPS) analysis.

Upgrading of waste stabilization ponds using a low-cost small-scale fine bubble diffused aeration system.

Waste Stabilization Ponds (WSPs) are known for the economical treatment of wastewater, especially if low-cost land is available. In this research to overcome some common operational problems such as undesirable color changes in ponds, severe odor problems, and most importantly, deviations from the effluent standards, the performance of a novel installation of a small-scale fine bubble diffused aeration system in the inlet zone of the facultative pond has been investigated. The long-term operational data of the system in two wastewater treatment plants in the east of Iran demonstrated that this system can significantly improve the efficiency of the treatment plant in addition to eliminating the mentioned operational problems. Pre-aeration of the inlet zone of the facultative ponds (Birjand WSPs) by the aeration system consists of 250 fine bubble disk diffusers (12 inches in diameter) and one 22 kW roots blower showed that purple color and odor problem can eliminate after almost two weeks and organic matter removal efficiency increased from 58 ± 15% to about 85 ± 10% based on BOD5. Almost similar results were obtained from the WSPs of Neyshabur. Long-term experimental results showed this system can be used successfully to control the process and upgrade these natural and efficient treatment processes, especially in developing countries.

Influence of low and high dosages of methyl and propyl parabens on membrane bioreactor (MBR) performance

ABSTRACT This study aimed to evaluate the degradation of methylparaben (MeP) and propylparaben (PrP) in synthetic wastewater in a membrane bioreactor (MBR) whose operation involved three stages: stage 1 (stabilization period), with no addition of parabens; stage 2, in which the MBR was fed with 0.5 mg L−1 of each paraben; and stage 3, in which both MeP and PrP were added, at 10 mg L−1each. The system performance was assessed by monitoring pH, temperature, effluent flow rate, transmembrane pressure, BOD, COD, suspended solids, and paraben concentration. The results confirmed that the MBR showed a good organic matter removal efficiency (> 92.2% for BOD; >91.6% for COD) and was not significantly affected by the addition of parabens at either low or high dosages. The volatile to total suspended solids ratio remained nearly constant, suggesting that the addition of parabens at a high concentration did not negatively impact the control of suspended solids. It was possible to achieve 96.0% of MeP and PrP removal in stage 2 ([parabens]0 = 0.5 mg L−1), and 86.0% of PrP removal in stage 3 ([PrP]0 = 10 mg L−1). Finally, biodegradation was found to be the main removal mechanism of parabens in the investigated MBR.

Adsorption of Natural Organic Matter and Phosphorus from Surface Water Using Heated Aluminum Oxide (Predeposited) Dynamic Membrane Adsorber

The paper reports the removal of phosphorus and natural organic matter (NOM) from surface water by dynamic membrane (DM) adsorber. DM filter builds up as a layer of particles deposited via permeation through the membrane’s surface. This study reports the application of Heated Aluminium Oxide Particles (HAOPs) as a dynamic membrane adsorber. Filtration experiments were conducted with surface water and batch tests were carried out with synthetic water. The efficiency of phosphorus removal along with the efficiency of organics (represented as UV-254) removal was evaluated. Additionally, the impact of HAOPs surface loading on the changes of transmembrane pressure (TMP), the kinetics, isotherm modeling of the adsorption and the effect of the pH, the effect of ionic strength, the effect of coexisting organic matter on phosphorus removal efficiency were studied. In the case of phosphorus removal in batch adsorption experiments, its sorption kinetic and isotherm data were analyzed using pseudo-first- and pseudo-second-order models and Langmuir and Freundlich models, respectively. The results indicated that Langmuir adsorption isotherm fits the experimental data best (0.9894). The kinetics of phosphorus adsorption on HAOPs was best described by the pseudo-second-order model and the best removal was achieved at the pH 6–7 (96.65% on average). An increase in ionic strength did not impact the efficiency of phosphorus removal significantly. The outcome of this study highlights HAOPs efficiency in NOM removal up to 92% in filtration experiments. In the case of phosphorous, removal efficiency varied. For the highest HAOPs dose, the degree of phosphorus removal ranged up to 93 ± 5%. The same removal efficiency was observed for the lowest dose while for 17 g/m2 of HAOPs the fluctuations were larger and varied from 64.7% to 92%. The results demonstrate that HAOPs could potentially be applied in the removal of phosphorus from surface water, especially when there is a high concentration of phosphorus in the water. However, this process requires further research and optimization of its parameters.

Water Purification of Classical and Emerging Organic Pollutants: An Extensive Review

The main techniques used for organic pollutant removal from water are adsorption, reductive and oxidative processes, phytoremediation, bioremediation, separation by membranes and liquid–liquid extraction. In this review, strengths and weaknesses of the different purification techniques are discussed, with particular attention to the newest results published in the scientific literature. This study highlighted that adsorption is the most frequently used method for water purification, since it can balance high organic pollutants removal efficiency, it has the possibility to treat a large quantity of water in semi-continuous way and has acceptable costs.