Phosphorus Removal In Wastewater Research Articles

Phosphorus removal from fermented dairy manure concurrent with polyhydroxybutyrate-co-valerate synthesis under aerobic conditions

Wastewater phosphorus removal achieved biologically is associated with the process known as enhanced biological phosphorus removal (EBPR). In contrast with canonical EBPR operations that employ alternating anaerobic–aerobic conditions and achieve asynchronous carbon and phosphorus storage, research herein focused on phosphorus removal achieved under aerobic conditions synchronously with volatile fatty acid (VFA) storage as polyhydroxybutyrate-co-valerate (PHBV). 90.3 ± 3.4 % soluble phosphorus removal was achieved from dairy manure fermenter liquor; influent and effluent concentrations were 38.6 ± 9.5 and 3.7 ± 0.8 mgP/L, respectively. Concurrently, PHBV yield ranged from 0.17 to 0.64 mgCOD/mgCOD, yielding 147–535 mgCODPHBV/L. No evidence of EBPR mechanisms was observed, nor were canonical phosphorus accumulating organisms present; additionally, the polyphosphate kinase gene was not present in the microbial biomass. Phosphorus removal was primarily associated with biomass growth and secondarily with biomass complexation. Results demonstrate that concurrent PHBV synthesis and phosphorus recovery can be achieved microbially under aerobic dynamic feeding conditions when fed nutrient rich wastewater.

Structural design of La2(CO3)3 loaded magnetic biochar for selective removal of phosphorus from wastewater

High levels of phosphorus released into the environment can cause eutrophication issues in wastewater, therefore discharge concentrations of such element are regulated in many countries. This study addresses the pressing need for effective phosphorus removal methods by developing a novel La2(CO3)3 and MnFe2O4 loaded biochar composite (LMB). A remarkable adsorption capacity towards the three forms of phosphorus from wastewater, including phosphate, phosphite, and etidronic acid monohydrate (as a representative of organic phosphorus), was exhibited by LMB (88.20, 16.35, and 15.95 mg g−1, respectively). The high saturation magnetization value (50.17 emu g−1) highlighted the easy separability and recyclability of the adsorbent. The adsorption process was well described by the Langmuir isotherm model and the pseudo-second-order kinetic model, which mainly involved chemisorption. Characterization results confirm the effective loading of La2(CO3)3 with ligand exchange and electrostatic attraction identified as the primary mechanisms. Importantly, the LMB demonstrated exceptional selectivity for phosphorus in wastewater samples containing various substances, exhibiting minimal interference from competing ions (Cl−, NO3−, SO42−, and CO32−). These findings enhance the understanding of LMB's application in efficient wastewater phosphorus removal. Holding significant promise in wastewater remediation, the LMB acts as an effective adsorbent, contributing substantially to the prevention and control of various types of phosphorus pollutants, thereby mitigating wastewater eutrophication.

Migration electric-field assisted electrocoagulation with sponge biochar capacitive electrode for advanced wastewater phosphorus removal

Migrating electric field-assisted electrocoagulation (MEAEC) is a three-electrode electrochemical system, including waste flour-derived sponge biochar (SBC) as an adsorption electrode for efficient phosphorus removal from wastewater. The SBC was applied in the MEAEC system as a pseudo capacitance electrode with low energy consumption and reached an excellent effluent level (0.12 mg/L) with a 200-s treatment time in 1 mg/L phosphate synthetic wastewater. The SBC adsorption electrode had a total charge capacitance of 1.14 F/g with abundant micropores. Continuous charging and discharging at a constant voltage over 100 cycles demonstrated the excellent durability of the biochar electrodes. The energy demand of SBC-MEAEC was only 0.0058 kWh/m3 for 90% phosphate removal, which was 65% less than that of the control. The use of SBC in the MEAEC system greatly enhanced phosphate removal at low concentrations. In the SBC-MEAEC system, the electro-desorption synchronous electrocoagulation process demonstrated efficient concentration and release of ions after electro-adsorption. These results indicate that MEAEC with an SBC electrode could achieve a high level of phosphate removal with a much lower energy consumption than in previous studies. The recovered concentrated phosphorus flocs also contained fewer metal impurities than those in previous electrochemical approaches. The proposed desorption synchronous electrocoagulation utilizing waste-derived SBC electrodes provides a cost-effective pathway to treat low phosphorous-containing wastewater.

Preparation of Fe/C-MgCO3 micro-electrolysis fillers and mechanism of phosphorus removal.

Iron-carbon micro-electrolysis is effective for the removal of phosphorus in wastewater; however, meeting the stringent emission standards required for treatment is difficult. To meet these treatment standards, modified micro-electrolytic fillers were prepared from iron dust, powdered activated carbon, clay, and additives using an elevated temperature roasting process under an inert atmosphere. The results show that among several additives, the modified micro-electrolytic (Fe/C-MgCO3) fillers using MgCO3 were the most effective at phosphorus removal. The preparation conditions for the Fe/C-MgCO3 fillers and their effects on phosphorus removal performance were investigated. Under the optimal preparation conditions (calcination temperature: 800°C, Fe/C = 4:1, clay content 20%, and 5% MgCO3), the filler yielded a high compressive strength of 3.5MPa, 1h water absorption rate of 25.7%, and specific surface area and apparent density of 154.2 m2/g and 2689.2kg/m3, respectively. The iron-carbon micro-electrolysis process removed 97% of phosphorus in the wastewater by using the Fe/C-MgCO3 fillers, which was 14% more than the Fe/C filler. Electrostatic adsorption and surface precipitation were identified as the main phosphorus removal mechanisms, and the surface of the Fe/C-MgCO3 filler was continuously updated. These results demonstrated that Fe/C-MgCO3 is a promising filler for phosphorus removal in water treatment.

Formable porous biochar loaded with La-Fe(hydr)oxides/montmorillonite for efficient removal of phosphorus in wastewater: process and mechanisms

The development of biochar-based granule-like adsorbents suitable for scaled-up application has been attracting increasing attention in the field of water treatment. Herein, a new formable porous granulated biochar loaded with La-Fe(hydr)oxides/montmorillonite (LaFe/MB) was fabricated via a granulation and pyrolysis process for enhanced phosphorus (P) removal from wastewater. Montmorillonite acted as a binder that increased the size of the granulated biochar, while the use of Fe promoted the surface charge and facilitated the dispersion of La, which was responsible for selective phosphate removal. LaFe/MB exhibited rapid phosphate adsorption kinetics and a high maximum adsorption capacity (Langmuir model, 52.12 mg P g−1), which were better than those of many existing granulated materials. The desorption and recyclability experiments showed that LaFe/MB could be regenerated, and maintained 76.7% of its initial phosphate adsorption capacity after four adsorption cycles. The high hydraulic endurance strength retention rate of the developed material (91.6%) suggested high practical applicability in actual wastewater. Electrostatic attraction, surface precipitation, and inner-sphere complexation via ligand exchange were found to be involved in selective P removal over a wide pH range of 3–9. The thermodynamic parameters were determined, which revealed the feasibility and spontaneity of adsorption. Based on approximate site energy distribution analyses, high distribution frequency contributed to efficient P removal. The research results provide a new insight that LaFe/MB shows great application prospects for advanced phosphate removal from wastewater.Graphical

Effects of Alkali-Activated Algae Biochar on Soil Improvement after Phosphorus Absorption: Efficiency and Mechanism

Biochar is often used for the removal of phosphorus in wastewater. However, the improper treatment of adsorbed biochar might cause secondary pollution. In order to promote the recycling and harmless utilization of biochar with adsorbed phosphorus, a new modified biochar (ABC) was prepared from cyanobacteria in this study. The maximum adsorption capacity of ABC calculated from the Langmuir isotherm model was 38.17 mg·g−1. ABC was used to absorb phosphorus in wastewater, whose product (ABC/P) was used for soil improvement and soybean cultivation. The results showed that adding the proper amount of ABC/P could significantly increase the pH of the soil (from 6.52 ± 0.04 to 7.49 ± 0.08), organic matter content (from 34.02 ± 0.41 to 47.05 ± 0.14 g·kg−1), cation exchange capacity (from 3.01 ± 0.18 to 3.76 ± 0.07 cmol·kg−1), water-holding capacity (from 28.78 ± 0.34 to 35.03 ± 0.31%), effective phosphorus content, and total phosphorus content. Meanwhile, the soil alkaline phosphatase activity was improved. The plant height, root length, and fresh quality were promoted by planting soybeans in ABC/P-improved soil and were better than those of the control group. Therefore, ABC/P, as a new type of phosphorus fertilizer, has the potential for soil amendment for legume crops.

Removal of phosphorus from wastewater by Diutina rugosa BL3: Efficiency and pathway

A novel phosphorus removal yeast BL3 was isolated from an alternating anaerobic/aerobic biofilter and identified as Diutina rugosa by 26S rDNA gene sequence analysis. Yeast BL3 could effectively remove phosphorus from synthetic wastewater containing 2–20 mg/L phosphorus under optimal environmental conditions. The highest phosphorus removal efficiency was above 70% under the conditions of DO 6.86 mg/L, C/P ratios of 60, N/P ratios of 3.3, pH 6.0–9.0, and at 25.0–35.0 °C. The phosphorus distribution in the aqueous solution and different components of yeast BL3 analysis indicated that around 55%–70% and 20%–40% of removed phosphorus were transferred into extracellular polymeric substances (EPS) and yeast cells, respectively. The plausible phosphorus transfer pathway was proposed based on the phosphorus distribution and species analysis, suggesting the important role of EPS as a phosphorus reservoir. These results indicate that yeast BL3 can efficiently remove phosphorus under aerobic conditions without alternating anaerobic/aerobic cycling, and thus has significant potential for practical application in wastewater phosphorus removal.

Removal of phosphorus in wastewater by sinusoidal alternating current coagulation: performance and mechanism

ABSTRACT The effects of initial total phosphorus (TP) concentration, current density, conductivity and initial pH value on the removal rate of TP and energy consumption, as well as the behaviour and mechanism of phosphorus removal, were investigated by sinusoidal alternating current coagulation (SACC). The flocs produced by SACC were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy FTIR and X-ray photo electron spectroscopy. The thermodynamic and kinetic behaviours of phosphorus removal by iron sol adsorption were also studied in detail. In a self-made SACC reactor equipped with five sets of parallel iron electrodes spacing 10 mm, the removal rate of TP reached 90.9% for a pH 7.0 wastewater with 5 mg dm−3 TP (κ = 800 μS cm−1) after being treated for 60 min by applying 2.12 mA cm−2 sinusoidal alternating current. Compared with direct current coagulation (DCC), SACC exhibits a higher removal efficiency of phosphorus due to the stronger adsorption of the produced flocs. It was found that the adsorption in the SACC process follows pseudo-second-order kinetic with the involvement of the intra-particle model. The adsorption of iron sol to phosphorus was an endothermic and spontaneous process, and its adsorption behaviour can be characterized with Langmuir and Redlich–Peterson isothermal adsorption models. SACC may be employed for the treatment of more complex wastewater combined with biological and/or electrochemical techniques.

The scientometric analysis of the research on microalgae-based wastewater treatment.

This study explores the characteristics of the literature on microalgae-based wastewater treatment during the past 20years, based on the Web of Science Core Collection database and its scientometric techniques. The results reveal that the literature on microalgae-based wastewater treatment has grown rapidly with 2621 publications and 54,388 citations in total. Most of the document types are journal articles, constituting 80.7% of the total records. China and the USA are the two most active countries, regarding the publications and cooperation in this filed from the viewpoint of the number of publishing papers, total number of citations, and the number of multinational author papers. The Chinese Academy of Sciences is the largest institutional contributor, publishing 2.3% of the papers, followed by the Indian Institute of Technology (2.2%) and Council of Scientific & Industrial Research (2.1%). The most publishing author is Ruan (35 papers) with the highest number of citation (2460 times). "Bioresource Technology" is the most publishing journal with 365 published papers, while 36.2% of the total sample is published in the subject area of "Environmental Sciences Ecology." The most cited paper in the past 20years is a review of the status of phosphorus removal in wastewater by de-Bashan in 2004. Bibliometric analysis has systematically combed the development system of microalgae-based wastewater treatment in the past 20years and has a great potential to gain valuable insights for the future development, which provides a supplement to the common content analysis.

The vertical recycled concrete aggregate filter for removal of phosphorus in wastewater

The irresponsible disposal of untreated wastewater into waters, soil and groundwater results in polluted water resources. Moreover, nutrients such as phosphorus have become culprits of concern in accelerating eutrophication. Besides, this issue could cause water poisoning and the degradation of recreational opportunities. Therefore, for justifying this problem, it is important to understand the quantity of phosphorus (P) flows by using recycled concrete aggregate (RCA) as filter materials. RCA used as a filter system has emerged as an alternative technology for phosphorus removal. This can overcome the problem of construction site waste by converting the waste into valuable products. Thus, this study aims to investigate the physical and chemical characteristics of RCA that influenced adsorption of P and the percentage of phosphorus removal from synthetic wastewater by using two different sizes of RCA. A total of five vertical recycled concrete aggregate filter was designed. The samples taken from influent and effluent were tested once a week and analyzed to determine pH and percentage removal phosphorus. RCA was analyzed using Scanning Electron Microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDX) testing to determine chemical composition. The results show that RCA primarily contained aluminium, calcium, and magnesium that could enhanced the phosphorus adsorption. The RCA with size 5 to 10 mm is shown to have high potential to remove phosphorus up to 99.57%. The higher the size of RCA, the higher percentage of phosphorus removal. In conclusion, RCA has the potential to remove phosphorus from wastewater.

Optimization of Wastewater Phosphorus Removal in Winter Temperatures Using an Anaerobic–Critical Aerobic Strategy in a Pilot-Scale Sequencing Batch Reactor

Biological phosphorus removal using an anaerobic–aerobic sequencing batch reactor (SBR) in a low temperature can be difficult to remove, and aeration always accounts for nearly half of the total electricity costs at many wastewater treatment plants. In this study, a pilot-scale anaerobic–critical aerobic SBR (A–CA SBR) was developed for synthetic domestic wastewater. More importantly, the phase, whose concentration of diffused oxygen was controlled at 1.0–1.5 mg/L, was defined as a critical aerobic phase, which reduced expenses during the operation. To be specific, half of the ammonia was removed within 10 days and no NO3−–N was accumulated during the process. From the SEM and metagenome analysis, Rhodocyclus, Zooglea, Dechloromonas, and Simplicispira had the ability to remove phosphorus and NO3−–N simultaneously, which proved the existence of a potential double-layer sludge structure under an A–CA operational condition. All of the results disclose that the pilot-scale A–CA SBR is a reliable manipulation strategy for phosphorus removal under low temperatures, which can hopefully apply to practical wastewater remediation.

Removal of Phosphorus from Synthetic Wastewater Using Recycled Concrete Aggregates as a Filter Medium

These days, sustainability has become a primary concern as the large amount of natural resources are being used to produce materials such as concrete. Concrete from the construction industry constitutes the major proportion of construction waste. This could bring negative impact including depletion of natural resources, pollution, increasing landfill space, and high cost of waste disposal. All of these negative impacts are the sustainability issues that should be concentrated on. Hence, alternative methods have been introduced in order to reduce waste by recycling concrete waste. One of the alternative methods that can be used is by reusing recycled concrete aggregates (RCA) from discarded waste cubes. RCA can be used to produce new concrete but it will generally have a lower performance compared to normal concrete. Thus, the present study introduces an alternative method which is by reusing the RCA as a water filter medium to remove phosphorus from wastewater. Phosphorus is one of the inorganic compounds found in wastewater that can lead to environmental problems such as eutrophication. Based on previous studies, many types of materials with various chemical compositions have been used for phosphorus removal from wastewater. Therefore, this study demonstrates the ability of RCA as an alternative method for phosphorus removal from wastewater. In addition, three different factors have been considered in the removal of phosphorus namely, different initial concentration of phosphorus, different sizes of RCA and dosage of RCA used during the treatment process. Based on the experiments conducted, the lowest initial concentration of phosphorus of 10 mg/L, the smallest RCA size ranging between 0mm to 5mm and the highest RCA dosage of 50g resulted in the highest percentage of phosphorus removal in wastewater.

Highly effective wastewater phosphorus removal by phosphorus accumulating organism combined with magnetic sorbent MFC@La(OH)3

To enhance the efficiency of phosphate removal by phosphorus accumulating organisms (PAOs), a magnetic Fe3O4 core-shell (MFC) sorbent was synthesized to remove the intracellular phosphorus of PAOs. The MFC was prepared by the hydrothermal method, and then functionalized with La(OH)3 by depositing on the MFC surface. The sorbent (MFC@La(OH)3) was easy to separate from wastewater and had a high phosphate adsorption capacity of 45.45 mg/g at 30 °C. The batch experiments were conducted to probe the influence of adsorbent on PAOs (Pseudomonas putida). The results showed that the adsorbent could inhibit the growth of microorganism by competing for the phosphate in solution, and further improving the hydrolysis of polyphosphates (polyP) from microorganism. The microorganism after the hydrolysis of polyP could accumulate phosphate more rapidly when it was added into phosphorus-rich medium. The optimized condition for polyP hydrolysis from microorganism was 0.1 g/100 mL of sorbent dosage and 1 h of contacting time. The sorbent exhibited stable phosphate adsorption behavior after 5 adsorption-desorption cycles. Phosphate could be effectively recovered through the regeneration of phosphate loaded MFC@La(OH)3 under alkaline condition. The present findings indicate that PAOs combined with MFC@La(OH)3 is a novel and highly effective method for removing phosphate in wastewater and recovering phosphorus resource.

Influences of operational parameters on phosphorus removal in batch and continuous electrocoagulation process performance.

Performance of an electrocoagulation (EC) process in batch and continuous operating modes was thoroughly investigated and evaluated for enhancing wastewater phosphorus removal under various operating conditions, individually or combined with initial phosphorus concentration, wastewater conductivity, current density, and electrolysis times. The results revealed excellent phosphorus removal (72.7-100%) for both processes within 3-6min of electrolysis, with relatively low energy requirements, i.e., less than 0.5kWh/m3 for treated wastewater. However, the removal efficiency of phosphorus in the continuous EC operation mode was better than that in batch mode within the scope of the study. Additionally, the rate and efficiency of phosphorus removal strongly depended on operational parameters, including wastewater conductivity, initial phosphorus concentration, current density, and electrolysis time. Based on experimental data, statistical model verification of the response surface methodology (RSM) (multiple factor optimization) was also established to provide further insights and accurately describe the interactive relationship between the process variables, thus optimizing the EC process performance. The EC process using iron electrodes is promising for improving wastewater phosphorus removal efficiency, and RSM can be a sustainable tool for predicting the performance of the EC process and explaining the influence of the process variables.

A dynamic physicochemical model for chemical phosphorus removal

A dynamic physico-chemical model for chemical phosphorus removal in wastewater is presented as a tool to optimize chemical dosing simultaneously while ensuring compliant effluent phosphorus concentration. This new model predicts the kinetic and stoichiometric variable processes of precipitation of hydrous ferric oxides (HFO), phosphates adsorption and co-precipitation. It is combined with chemical equilibrium and physical precipitation reactions in order to model observed bulk dynamics in terms of pH. The model is calibrated and validated based on previous studies and experimental data from Smith et al. (2008) and Szabo et al. (2008) as a first step for full-plant implementation. The simulation results show that the structure of the model describes adequately the mechanisms of adsorption and co-precipitation of phosphate species onto HFO and that the model is robust under various experimental conditions.

Potential for Phosphorus Removal in Wastewater Using Volcanic Rock as Adsorbent

Phosphorus contamination in aquatic system was a widespread problem in Zhejiang province due to the excess use of detergent, agrochemicals and other organic phosphorus chemicals. Volcanic rock, an adsorbent with porous structure and large surface area, was applied for phosphorus removal in wastewater. The results showed that the phosphorus removal rate and equilibrium time had positive correlation with the initial phosphorus concentration, while the volcanic rock particle size could also affect the adsorption performance as volcanic rock with smaller particle size used to have a larger cation exchange capacity and higher surface area. Both Langmuir adsorption and the Freundlich adsorption happened throughout phosphorus removal process, showing the strong capacity and capability of volcanic rock as absorbent for phosphorus wastewater. It is promising to use volcanic rock in phosphorus water/wastewater purification systems due its large quantities and accessibility in nature.

Electrolytic Removal of Phosphorus in Wastewater with Noble Electrode under the Conditions of Low Current and Constant Voltage

Electrolytic Removal of Phosphorus in Wastewater with Noble Electrode under the Conditions of Low Current and Constant Voltage

A Dynamic Physicochemical Model for Chemical Phosphorus Removal

A dynamic physico-chemical model for chemical phosphorus removal in wastewater is presented as a tool to optimize chemical dosing simultaneously while ensuring compliant effluent phosphorus concentration. This new model predicts the kinetic and stoichiometric variable processes of precipitation of hydrous ferric oxides (HFO), phosphates adsorption and co-precipitation. It is combined with chemical equilibrium and physical precipitation reactions in order to model observed bulk dynamics in terms of pH. The model is calibrated and validated based on previous studies and experimental data from Smith et al. (2008) and Szabo et al. (2008) as a first step for full-plant implementation. The simulation results show that the structure of the model describes adequately the mechanisms of adsorption and co-precipitation of phosphate species onto HFO and that the model is robust under various experimental conditions.

Removal of Phosphorus in Wastewater by Ca-Impregnated Activated Alumina

Phosphorus removal during discharge of wastewater is required to achieve in a very high level because eutrophication occurs even at a very low phosphorus concentration. However, there are limitations in the traditional technologies in the removal of phosphorus at very low concentration, such as at a level lower than 0.1 mg/L. Through a series of experiments, a possible technology which can remove phosphate to a very low level in the final effluent of wastewater was suggested. At first Al, Zn, Ca, Fe, and Mg were exposed to phosphate solution by impregnating them on the surface of activated alumina to select the material which has the highest affinity to phosphate. Ki- netic tests and isotherm tests on phosphate solution have been performed on four media, which are Ca-impregnated activated alumina, activated alumina, Ca-impregnated loess ball, and loess ball. Results showed that Ca-impregnated activated alumina has the highest capacity to adsorb phosphate in water. Scanning electron microscope image analysis showed that activated alumina has high void volume, which provides a large surface area for phosphate to be adsorbed. Through a continuous column test of the Ca-impregnated activated alumina it was discovered that about 4,000 bed volumes of wastewater with about 0.2 mg/L of phosphate can be treated down to lower than 0.14 mg/L of concentration.

Acute and Chronic Responses of Activated Sludge Viability and Performance to Silica Nanoparticles

Recently, the potential health and environmental risks of silica nanoparticles (SiO(2) NPs) are attracting great interest. However, little is known about their possible impacts on wastewater biological nitrogen and phosphorus removal. In this study, the acute and chronic effects of SiO(2) NPs on activated sludge viability and biological nutrient removal performance were investigated. It was found that the presence of environmentally relevant concentration (1 mg/L) of SiO(2) NPs caused no adverse acute and chronic effects on sludge viability and wastewater nitrogen and phosphorus removal. However, chronic exposure to 50 mg/L SiO(2) NPs induced the increase of effluent nitrate concentration, and thus depressed the total nitrogen (TN) removal efficiency from 79.6% to 51.6% after 70 days of exposure, which was due to the declined activities of denitrifying enzymes, nitrate reductase and nitrite reductase. Wastewater phosphorus removal was insensitive to 1 and 50 mg/L SiO(2) NPs after either the acute or chronic exposure, because the critical factors closely related to biological phosphorus removal were not significantly changed, such as the activities of exopolyphosphatase and polyphosphate kinase and the intracellular transformations of polyhydroxyalkanoates and glycogen. Denaturing gradient gel electrophoresis (DGGE) analysis revealed that the bacterial community structure was changed after long-term exposure to 50 mg/L SiO(2) NPs, and the quantitative PCR assays indicated that the abundance of denitrifying bacteria was decreased, which was consistent with the declined wastewater nitrogen removal.