Removal Rates Of Total Phosphorus Research Articles

Integration of hydrothermal liquefaction of Cyanophyta and supercritical water oxidation of its aqueous phase products: Biocrude production and nutrient removal

Cyanophyta has the potential to produce biocrude via hydrothermal liquefaction (HTL). However, aqueous phase products (APs), as by-products of HTL, pose a risk of eutrophication for the high levels of carbon, nitrogen, and phosphorus. Supercritical water oxidation (SCWO) can efficiently convert organics into small molecules, offering a technique for the harmless treatment of APs. Effects of holding time, pressure, and moisture content on the biocrude yields from isothermal HTL (300 °C) and fast HTL (salt bath temperature of 500 °C) were comprehensively investigated. Biocrude properties were characterized by elemental analysis, FT-IR and GC–MS. Subsequently, the APs obtained under the conditions producing the highest biocrude yield were subjected to SCWO at 550 °C with different oxidation coefficients (n) from 0 to 2. Removal rates of chemical oxygen demand (COD), ammonia nitrogen (NH3−N), and total phosphorus (TP) were further explored. The results show that the highest biocrude yields from isothermal HTL and fast HTL were 24.2 wt% (300 °C, 1800 s, 25 MPa, and 80 wt% moisture content) and 21.9 wt% (500 °C, 40 s, 25 MPa, and 80 wt% moisture content), respectively. The biocrude primarily consisted of N-containing heterocyclic compounds, amides, and acids. SCWO effectively degraded the COD and TP in APs, while the NH3-N required further degradation. At n = 2, the highest removal rates of COD, NH3-N and TP were 98.5 %, 22.6 % and 89.1 %, respectively.

Degradation kinetics of organic matter in domestic sewage by sequencing batch reactor

The sequencing batch reactor (SBR) has become a popular sewage treatment process in various industries due to its strong impact load resistance and numerous other advantages. This study examines the variations of chemical oxygen demand chromium (CODcr), ammoniacal nitrogen (NH3-N), total bound nitrogen (TN) and total phosphorus (TP) with aeration time to investigate the degradation patterns of different pollutants during the SBR’s reaction stage. Additionally, an organic matter degradation kinetic model was developed. The experimental results showed that the CODcr and NH3-N in the reactor met the national discharge standards after two hours of influent. Furthermore, the removal rates of CODcr and NH3-N exceeded 85% and 99%, respectively, at the end of the final aeration. At the same time, the TN and TP removal rates remained stable at approximately 45% and 68%. The analysis of the kinetic model showed that the degradation process of organic matter followed a first-order kinetic equation: S=S0e−0.00012Xt. The regression model's fitting value exhibited a high degree of conformity with CODcr removal’s experimental results, with the average relative error of 5.52% falling within an acceptable range. Furthermore, the correlation coefficient (0.9966) indicated high accuracy and effectively represented the changes in organic matter throughout the SBR reaction stage. Consequently, this model can serve as a theoretical foundation for determining CODcr’s maximum treatment capacity in experimental wastewater.

Preparation of La/Mg modified sheep dung activated carbon and its adsorption characteristics for phosphorus in wastewater

The resource utilization of sheep dung from farming waste was evaluated in adsorption of total phosphorus (TP). Four types of modified sheep dung activated carbon (SDAC) were prepared: SDAC without metal (SDAC-N), SDAC with lanthanum (SDAC-La), SDAC with magnesium (SDAC-Mg), and SDAC with La and Mg (SDAC-La-Mg). The various SDACs prepared were tested in the adsorption TP from wastewater. The main components of the SDAC-La-Mg surface were MgO and La2O3. The SDAC-La-Mg surface was rich in functional groups such as CC and CO and acquired a negative charge. At 25 °C and pH of 4, the TP adsorption capacity of SDAC-La-Mg was 1.94 mg/g. Among the four SDAC adsorbents, SDAC-La-Mg exhibited the highest adsorption capacity. TP adsorption by SDAC-La-Mg followed the secondary kinetic and Langmuir isothermal adsorption models, primarily through chemisorption mechanisms such as ion exchange, chemical precipitation, and covalent bonding. SDAC-La-Mg was regenerated, and the TP removal rate remained at 65% after three regeneration cycles. Mg and La ions combine with carboxylate ions to form ligand compounds, enabling TP adsorption by displacing the -OH group on the surface of SDAC-La-Mg to form an inner complex. Thus, SDAC-La-Mg can be used as an effective adsorbent for TP in wastewater treatment.

Spark deposition of lanthanum-carbon composite nanoparticles embedded in a polypropylene membrane for phosphate removal in aqueous solutions

Eutrophication in water, such as rivers or lakes, is becoming increasingly serious. Controlling the phosphate concentration in such waters is the key to solving the eutrophication problem. The use of adsorption methods to limit the level of phosphate in aqueous solutions has the advantages of cost-effectiveness, ease of operation, and selectivity. In this study, a modified polypropylene (PP) membrane was used as the platform for the in-situ deposition of lanthanum-carbon (La-C) composite nanoparticles. Uniform lanthanum (La) and carbon (C) aerosols were deposited on the PP film using spark ablation, and the combined hydrothermal method was used to synthesise the nano-confinement crystal PP-La-C (PLC) for phosphorus removal in an aquatic environment. Because of the nanoconfinement of the PLC, particle agglomeration deactivation was effectively solved, and the doping of C changed the shape of La(OH)3 from particles to ultrafine nano-fibres, which resulted in a larger surface area and more abundant active sites, and the overall adsorption performance was improved. The addition of C reduced the cost, and La proved to be the main active site for phosphate capture. The adsorption test revealed a significant adsorption capability of 194.1 mg⋅P⋅g−1. Three variables, such as reaction time, dose, and original phosphate concentration, were selected and a model for predicting lake water phosphate removal efficiency was developed using the central composite design method. When PLC was used to treat water samples from Lake Qilu (Yunnan, China), the observed removal rate of total phosphorus was 94 %, which is consistent with the model prediction. A series of characterisations established that ligand exchange and multilayer adsorption were the main mechanisms of phosphorus removal.

Distinctive species interaction patterns under high nitrite stress shape inefficient denitrifying phosphorus removal performance

Denitrifying phosphorus removal using nitrite as an electron acceptor is an innovative, resource-efficient approach for nitrogen and phosphorus removal. However, the inhibitory effects of nitrite on anoxic phosphorus uptake and process stability are unclear. This study investigated the total phosphorus removal performance under nitrite stress and analyzed microbiome responses in 186 sludge samples. The results indicated that the total phosphorus removal rates and dominant taxon abundance were highly similar under nitrite stress. High nitrite stress induced a community-state shift, leading to unstable dynamics and decreased total phosphorus removal. This shift resulted from increased species cooperation. Notably, the shared genera OLB8 and Zoogloea under non-inhibitory nitrite stress, suggesting their vital roles in mitigating nitrite stress by enhancing carbon and energy metabolism. The response patterns of these bacterial communities to high nitrite stress can guide the design and optimization of high-nitrogen wastewater reactors.

Development of microalgal dual-cultures for enhanced productivity in sewage: An experimental study

Microalgae polycultures can be shown greater productivity than those that characterize monocultures. Nonetheless, rapid and ready identification of optimal microalgae combinations for highly productive polyculture systems remains a challenge. By assessing the corresponding nitrogen and phosphorus utilization efficiencies, this study aimed to identify microalgal combinations that might improve productivity. Ten high-biomass-producing microalgal species in municipal sewage habitats were cultivated in an artificial municipal sewage. Four high-yielding microalgae, which additionally showed complementary nitrogen and phosphorus nutrient utilization preferences, were selected for a subsequent dual-culture experiment. The D41 dual-culture system comprising Pediastrum sp. and Micractinium sp., showed the highest biocrude yield, at 17.5 mg/L/d, which was 13 % and 69 % higher than those of A4 and A1, respectively. Additionally, D41 showed the highest total phosphorus removal rate from artificial sewage, which was 27 % higher than that of Pediastrum sp. monoculture (A4) and 22 % higher than that of the Micractinium sp. monoculture (A1). Therefore, this study demonstrated that, (a) biomass production and nitrogen and phosphorus utilization rates of the constructed microalgae dual-culture systems were higher than those of monocultures, (b) phosphorus was identified as the limiting nutrient for further enhancing microalgae productivity, and (c) the dual-culture system showed intermediate characteristics between those of the constituent monoculture systems, suggesting that microalgae can influence community structure. Through the development of adequate software packages that can integrate microalgae nutrient utilization preference of and microalgae community structure, future research will enable the development of more productive microalgae culture combinations.

Pressure of different level PFOS on aerobic granule sludge: Insights on performance, AGS structure, community succession, and microbial interaction responses

Perfluorooctane sulfonic acid (PFOS) has received much attention due to its potential environmental risks. However, the response of aerobic granular sludge (AGS) to PFOS exposure, particularly the microbial interactions, remains unclear. In this study, we investigated the particle structure of AGS, pollutant removal performance, community succession, and microbial interaction in the AGS system under different PFOS concentrations (0.1 and 1 mg/L). The mass balance showed that PFOS was mainly removed by adsorption with a removal rate of >85 %. PFOS caused some particles to break up and decreased the average particle size from 3.37 mm to 2.64 mm. It also significantly decreased the total nitrogen and total phosphorus removal rates, which was consistent with the deterioration of microbial activity, such as denitrification rate (25 % inhibition), phosphorus uptake rate (73.19 % inhibition), and phosphorus release rate (73.33 % inhibition). PFOS promoted the secretion of extracellular polymer (EPS) in AGS, especially proteins, leading to poor particle hydrophobicity. The network analysis illustrated that PFOS slowed down the information transfer between microorganisms, and increased the competition between them, which may be responsible for the deterioration of the system performance. Connections related to rare species accounted for >75 % of the network, suggesting that rare species have an indispensable role in community information exchange. In addition, rare species acted as seed banks for microorganisms, and under PFOS stress, they transformed into keystone species, which could contribute to system stabilization. This study provides new insights into the effects of PFOS on microbial interactions in AGS systems and the roles of rare species in the AGS microbial community.

An integrated process of Fe/C micro-electrolysis-anaerobic hydrolyze-microalgae for treatment of high concentration pharmaceutical wastewater

As a high concentration wastewater of high organic matter content, many toxic substances, large amounts of organic solvents and poor biochemistry, pharmaceutical wastewater is challenging to handle with a single water treatment technology. In this study, a combined process of Fe/C micro-electrolysis (Fe/C-ME)-anaerobic hydrolyze-microalgae was developed to treat high-concentration pharmaceutical wastewater (i.e. 100,000 mg/L chemical oxygen demand (COD), 2800 mg/L ammonia nitrogen (NH3-N) and 130 mg/L total phosphorus (TP)). Firstly, in the Fe/C-ME process, under optimal experimental conditions, the removal rates of COD, NH3-N and TP were 55 %, 36 % and 63 %, and it was worth mentioning that the removal of ammonia nitrogen and total phosphorus may be attributed to the complexation and flocculation of hydrated iron ions. Secondly, the outer circulation anaerobic reactor (OCAR) performed biochemical treatment on pretreated pharmaceutical wastewater, 85 % of COD was removed, and it was found that through anaerobic digestion, and further hydrolyzed and acidified macromolecular pollutants into small molecules to reduce the impact load, which was conducive to the subsequent digestion and absorption of microalgae and improved the treatment efficiency of the aerobic section. The microalgae cultivated by heterotrophy using anaerobic effluent, directly used NH3-N and TP in wastewater to synthesize substances needed for self-growth and reproduction, and removed 88 %, 91 % and 83 % of COD, NH3-N and TP, respectively. The final results indicated that the removal rates of COD, NH3-N and TP in the integrated process of Fe/C-ME-anaerobic hydrolysis-microalgae were 99.8 %, 98.6 % and 98.5 %, respectively, demonstrating that the coupling process is an effective method for treating high-concentration pharmaceutical wastewater.

Elevated purification of urban rainwater runoff using a calamus constructed wetland with multi-layer carrier fillers

Urban water body pollution caused by storm-water runoff is increasingly serious due to rising global urbanization. We evaluated the effectiveness of a calamus vertical flow constructed wetland purifying urban runoff. This wetland was constructed using three filler layers of rare earth porcelain sand, ceramsite, and clinoptilolite respectively. The results revealed that under the optimal hydraulic load of 80 L/(m2·h), pollutants removal efficiency with the study wetland reached 89.9 %, 95.0 %, 84.7 %, and 76.2 % for the moderate rain runoff, in terms of COD (chemical oxygen demand), SS (suspended solids), TN (total nitrogen) and TP (total phosphorus) respectively. The removal rates of COD, SS, TN and TP by plants and the soil layer together were up to 64.9 %, 50.0 %, 58.1 %, and 28.6 %, respectively, while the rare earth porcelain sand layer had the highest contribution to the removal rate of TP (42.8 %), and the filler removal effect for phosphorus was more significant than that of plants and the soil layer. Although the influent water quality fluctuates with runoff from moderate to heavy torrential rain intensities, most of the effluent water meets the discharging standards. While the effluent quality of light rain runoff with high pollution load slightly exceeded the standards, it still removal rate as high as 88 %, 96.3 %, 73.3 %, 76.2 % for COD, SS, TN, TP.

A semi-continuous efficient strategy for removing phosphorus and nitrogen from eel aquaculture wastewater using the self-flocculating microalga Desmodesmus sp. PW1

The phosphorus content in eel aquaculture wastewater exceeds the discharge standard, and the amount of wastewater discharged is substantial. Therefore, there is an urgent need to explore an economical and efficient method of treating aquaculture wastewater. This study explored the use of Desmodesmus sp. PW1, a type of microalgae, to treat eel aquaculture wastewater. By optimizing the conditions, Desmodesmus sp. PW1 achieved a total phosphorus (TP) removal efficiency of 92.3%, as well as total nitrogen (TN) and ammonia nitrogen (NH4+-N) removal efficiency of 99%, using a photoperiod of 24:0, a temperature of 25 °C, and an inoculation amount of 15%. Furthermore, Desmodesmus sp. PW1 demonstrated a high self-flocculating efficiency (>90%) within 100 min of settling, which facilitated biomass recovery. Subsequently, a semi-continuous treatment process mode was established with a sewage renewal rate of 90%. The results showed that after four rounds of sewage renewal operations, the microalgae biomass in the sewage treatment system could be maintained between 160.0 and 220.0 mg/L, and the average removal rate of TP was 0.13 mg/(L * h). The lipid content of algae cells collected in the semi-continuous treatment system for eel aquaculture wastewater was as high as 36.5%, and the biodiesel properties met the biodiesel standards authorized by Europe and the United States. Overall, this study provides an economical and effective strategy for converting wastewater into high-value microalgae products.

Seasonal purification efficiency, greenhouse gas emissions and microbial community characteristics of a field-scale surface-flow constructed wetland treating agricultural runoff

Controlling nonpoint source pollution (NPSP) is very important for protecting the water environment, and surface-flow constructed wetlands (SFCWs) have been widely established to mitigate NPSP loads. In this study, the pollutant removal efficiencies, greenhouse gas (GHG) emissions, and chemical and microbial community properties of the sediment in a large-scale SFCW established beside a plateau lake (Qilu Lake) in southwestern China to treat agricultural runoff were evaluated over a year. The SFCW performed best in terms of nitrogen removal in autumn (average efficiency of 63.5% at influent concentrations of 9.3–35.4 mg L−1) and demonstrated comparable efficiency in other seasons (23.7–40.0%). The removal rates of total phosphorus (TP) and chemical oxygen demand (COD) were limited (18.6% and 12.4% at influent concentrations of 1.1 and 45.5 mg L−1 on average, respectively). The SFCW was a hotspot of CH4 emissions, with an average flux of 31.6 mg m−2·h−1; moreover, CH4 emissions contributed the most to the global warming potential (GWP) of the SFCW. Higher CH4 and N2O fluxes were detected in winter and in the front-end section of the SFCW with high pollutant concentrations, and plant presence increased CH4 emissions. Significant positive relationships between nutrient and heavy metal contents in the SFCW sediment were detected. The microbial community compositions were similar in autumn and winter, with Thiobacillus, Lysobacter, Acinetobacter and Pseudomonas dominating, and this distribution pattern was clearly distinct from those in spring and summer, with high proportions of Spirochaeta_2 and Denitratisoma. The microbial co-occurrence network in spring was more complex with stronger positive correlations than those in winter and autumn, while it was more stable in autumn with more keystone taxa. Optimization of the construction, operation and management of SFCWs treating NPSP in lake watersheds is necessary to promote their environmental benefits.

Lanthanum and magnesium activated palygorskite for adsorption of phosphate in piggery wastewater.

Removing phosphate from wastewater can help alleviate eutrophication. Therefore, in this study, lanthanum and magnesium were loaded onto the thermally modified palygorskite (PAL) using a coprecipitation method, and a composite material was prepared for phosphate recovery. In the pH range of 2-7, the material can effectively adsorb the phosphate. In the kinetic experiment, the material was able to rapidly adsorb phosphate within 4 h of the beginning of the reaction. The adsorption isotherm result of the material was in accordance with Freundlich isotherm model. When pH was 7, the theoretical maximum adsorption capacity was 20.4 mg P/g. When phosphate coexisted with CO32- and HCO3-, the adsorption was significantly inhibited. In the adsorption-desorption experiment, the material can be reused at least five times after elution with 1 mol/L of sodium hydroxide solution. The equilibrium adsorption capacity of the material for total phosphorus in piggery wastewater was 7.25 mg P/g, achieving a total phosphorus removal rate of 95.3%. The characterization of XRD, FT-IR and XPS suggested that phosphate was mainly exchanged with La-OH in the material, forming an amorphous LaPO4 complex.

Efficient Adsorption Removal of Phosphate from Rural Domestic Sewage by Waste Eggshell-Modified Peanut Shell Biochar Adsorbent Materials.

In order to promote the improvement of the rural living environment, the treatment of rural domestic sewage has attracted much attention in China. Meanwhile, the rural regions' sewage discharge standards are becoming increasingly stringent. However, the standard compliance rate of total phosphorus (TP) is very low, and TP has become the main limiting pollutant for the water pollutants discharge standards of rural domestic sewage treatment facilities. In this study, waste eggshell (E) was employed as a calcium source, and waste peanut shell (C) was employed as a carbon source to prepare calcium-modified biochar adsorbent materials (E-C). The resulting E-C adsorbent materials demonstrated efficient phosphate (P) adsorption from aqueous solutions over the initial pH range of 6-9 and had adsorption selectivity. At an eggshell and peanut shell mass ratio of 1:1 and a pyrolysis temperature of 800 °C, the experimental maximum adsorption capacity was 191.1 mg/g. The pseudo second-order model and Langmuir model were best at describing the adsorption process. The dominant sorption mechanism for P is that Ca(OH)2 is loaded on biochar with P to form Ca5(PO4)3OH precipitate. E-C was found to be very effective for the treatment of rural domestic sewage. The removal rate of TP in rural domestic sewage was 91-95.9%. After adsorption treatment, the discharge of TP in rural sewage met the second-grade (TP < 3 mg/L) and even first-grade (TP < 2 mg/L). This study provides an experimental basis for efficient P removal by E-C adsorbent materials and suggests possible applications in rural domestic sewage.

Stormwater runoff pollution control performance of permeable concrete pavement and constructed wetland combined system: toward on-site reuse.

Urban waterlogging and the deterioration of receiving water quality caused by stormwater runoff have become increasingly significant problems. Based on the concept of combining grey and green infrastructure, a combined permeable concrete pavement (PCP) and constructed wetland (CW) system has been developed to treat stormwater runoff and enable on-site reuse. The results showed that the removal rate of suspended solids (SS) by PCP ranged from 96.61 to 99.20%; however, the chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) concentrations in the effluent did not meet the standards required for rainwater reuse. For the combined PCP-CW system, the removal rates of COD, TN and TP by the CW were 48.45-75.12%, 47.26-53.05%, and 59.04-75.28%, respectively, under different hydraulic loading (HL) rates; thus, the effluent TN concentrations did not consistently meet the reuse standards. Further optimization of aeration in different parts of the CW revealed that aeration in the middle and front sections of the wetland had the most significant effect on pollutant removal, under which the TN concentrations in the effluent met the standard required for reuse. The effluent from the combined PCP-CW system was able to fully meet the stormwater reuse standards under these optimized conditions, and the reuse of urban stormwater runoff can therefore be realized.

Effects of ultrasonic lysis frequency on sludge lysis-cryptic growth: Sludge reduction, microbial community, and metabolism

Ultrasonic irradiation can effectively achieve in-situ sludge reduction, and the frequency of ultrasonic lysis may affect the performance. This study explored the effect of ultrasonic lysis frequencies of 1/d, 2/d, and 1/3d on lysis-cryptic growth of sludge and investigated changes in sludge and microorganisms in detail. The optimal ultrasonic lysis frequency was 1/d, and sludge reduction reached 47.90%. The use of ultrasound did not change the chemical oxygen demand (COD), total nitrogen (TN), and ammonia nitrogen (NH3-N) removal, but decreased the removal rate of total phosphorus (TP); the removal rate of TP was the lowest (37.58%) at an ultrasonic lysis frequency of 2/d. The use of ultrasound decreased the average particle size of sludge, and the minimum sludge particle size was 16.98 μm at an ultrasonic lysis frequency of 2/d. SEM demonstrated that the introduction of ultrasound roughened the sludge surface. FTIR and XPS demonstrated that the most significant change in functional group strength occurred at an ultrasonic lysis frequency of 1/3d. Extracellular polymeric substances (EPS) increased the most at an ultrasonic lysis frequency of 1/d. The introduction of ultrasound did not change the microbial communities of sludge, with Firmicutes, Actinobacteria, and Patescibacteria being the main microbial communities. Furthermore, the introduction of ultrasound did not change the metabolic pathway or key genes of sludge microorganisms but increased key enzymes related to carbon, nitrogen, and phosphorus metabolism.

Purification Efficiency of Eutrophic Water by Three Submerged Plants

The increase of nitrogen and phosphorus causes eutrophication in water bodies. Using submerged plants to decrease the pollution from water bodies is an effective way. In this research, three common submerged plants (Vallisneria natans, Hydrilla verticillata, and Ceratophyllum demersum) and their combinations were used to purify eutrophic water. The control treatment did not contain any plants. The removal effects and dynamic regulations of the three plants with their combinations of nutrients (such as nitrogen and phosphorus) in water were analyzed. All three species and their combinations above could grow in the eutrophic water and efficiently remove aquatic nutrients. All the treatment groups had a higher pollutant removal rate for total nitrogen (TN) and total phosphorus (TP) than that of the blank control. In these treatment groups, treatment F (50 g Vallisneria natans plus 50 g Ceratophyllum demersum) had the highest removal rate of TP at 57.53%; treatment B (100 g Vallisneria natans) had the best removal rate of TN at 92.04 %. Among these plants and their combinations, Vallisneria natans and Ceratophyllum demersum showed better purification ability; the combination of these two submerged plants and the combination of three submerged plants were more applicable for the restoration of eutrophic water.

Research on the removal of pollutants from water environment by lanthanum modified montmorillonite

&lt;p&gt;The management of water pollution has been one of the main problems as people pay more and more attention in the current society to the preservation and repair of the natural environment. In this paper, natural montmorillonite was modified with starch as well as lanthanum chloride. The removal efficiency of various modified montmorillonites on pollutants was examined by simulating the water quality conditions of heavily polluted lake reservoirs in order to provide new eco-friendly and effective materials for the treatment of heavily polluted lakes and reservoirs. The experimental results showed that: The nitrogen removal rates of Na-Mont, St-Mont, La-Mont, St-La-Mont and La-St-Mont for 2 mg/L TN solution were 28.48%, 5.18%, 59.55%, 98.39%, 64.73%, respectively, and total phosphorus removal rates for 10 mg/L TP contaminated solution were 6.24%, 4.16%, 87.41%, 93.66%, 91.58% and for 100 mg/L COD solution the removal rates were 32.37%, 41.46%, 51.68%, 86.89%, 77.8%, respectively. By exploring the effect of La6-Mont adsorption for Cr6+ removal at different temperatures as well as reaction times, the results showed that the Cr6+ removal at saturation of La6-Mont adsorption was 76%, 80.5%, and 82.5% at the reaction temperatures of 15℃, 25℃, and 35℃, respectively. Among them, the removal rates of St-La-Mont reached more than 85%, 50% and 70% for COD, TN and for TP, respectively, and can be applied as fillers for enhanced artificial fast infiltration systems. The light rare earth composites La-St-Mont and LaCl3-Mont have achieved removal rates of 35%, 50% and more than 90% for COD, TN and for TP, respectively, and can be used as effective purification materials for treating water quality of heavily polluted lakes and reservoirs. Meanwhile, La6-Mont can effectively fix heavy metal ions and avoid the release of endogenous pollution in the bottom mud, which can be used as a material for the treatment of bottom mud in lake reservoirs. This shown that lanthanum, a light rare earth element, modified montmorillonite can not only remove a range of pollutants from water bodies but also has excellent removal rates. Additionally Besides, starch, lanthanum and montmorillonite are widely available materials with high economic benefits. Therefore, further studies on St-La-Mont, La-St-Mont, LaCl3-Mont and La6-Mont can provide new materials for the treatment of pollution in heavily polluted lakes and reservoirs.&lt;/p&gt;&#x0D;

Removal of 17α-ethinylestradiol and total phosphorus in a sequencing batch reactor under two different sludge retention-time conditions

Sewage treatment systems can prevent the direct discharge of endocrine disruptors, such as 17α-ethinylestradiol (EE2), into the environment. Treatment systems capable of promoting total phosphorus (TP) removal, such as sequencing batch reactors (SBRs), are promising in this regard. Two lab-scale SBRs with different sludge retention times (SRTs) were assessed for their EE2 and TP removal rates. Anaerobic/aerobic/anoxic phases with cycles of 6 h were used to treat sewage containing EE2 at a concentration of 5 μg L-1. The removal rates of chemical oxygen demand and TP were approximately 80% for both the SBRs. Partial nitrification was observed in the SBRs. Initially, concentrations of EE2 above 1.0 μg L-1 in the treated sewage were measured. These concentrations were smaller in SBR 1, which used lower SRTs; EE2 was removed by sludge sorption. After the 56th cycle, the concentrations of EE2 in the treated sewage were below 0.1 μg L-1 in both the SBRs, indicating that its removal may have occurred by biodegradation due to acclimation to the process. Therefore, both TP removal and nitrification seem to play an important role in EE2 removal by SBRs.&#x0D; Keywords: A2O SBR, EE2 and TP removal, sewage treatments.

Treatment of compressed leachate from refuse transfer stations by freeze-melt method

A small amount of leachate with complex composition will be produced during the compressing of municipal solid waste in refuse transfer stations. In this study, the freeze-melt method, a green and efficient wastewater treatment technology, was used to treat the compressed leachate. The effects of freezing temperature, freezing duration, and ice melting method on the removal rates of contaminants were investigated. The results showed that the freeze-melt method was not selective for the removal of chemical oxygen demand (COD), total organic carbon (TOC), ammonia-nitrogen (NH3-N) and total phosphorus (TP). The removal rate of contaminants was positively correlated with freezing temperature and negatively correlated with freezing duration, and the slower the growth rate of ice, the higher the purity of ice. When the compressed leachate was frozen at −15 °C for 42 h, the removal rates of COD, TOC, NH3-N and TP were 60.00%, 58.40%, 56.89% and 55.34%, respectively. Contaminants trapped in ice were removed during the melting process, especially in the early stages of melting. The divided melting method was more beneficial than the natural melting method in removing contaminants during the initial stage of melting, which contributes to the reduction of produced water losses. This study provides a new idea for the treatment of small amounts of highly concentrated leachate generated by compression facilities distributed in various corners of the city.

Engineered Biomaterials for Reducing Phosphorus and Nitrogen Levels from Downstream Water of Aquaculture Facilities

The United States (U.S.) has a nearly USD 17 billion seafood trade deficit annually. However, the U.S. aquaculture industry faces strict micronutrient (e.g., phosphorus and nitrogen) level mandates that negatively impact fish production, especially for the state of Idaho, which produces 70–75% of the nation’s rainbow trout. This study investigates the sustainability benefits of producing engineered biomaterials from lignocellulosic-based feedstocks near collection sites via portable biorefineries for use by fish farms to reduce eutrophication (oversupply of micronutrients) impacts. In this study, sustainability assessments are performed on a case study in southern Idaho, the largest U.S. commercial producer of rainbow trout. The results show that 20 and 60 min of water treatment, using small particle size biomaterial from lodgepole pine, has the highest total phosphorus removal rate, at 150–180 g of phosphorus per 1 metric ton of engineered biomaterials. The results of techno-economic and environmental impacts studies indicate that pinewood-based biomaterials production cost ranges from USD 213 USD 242 per ton and reduces the eutrophication potential by 5–17 kg PO4eq/ton. Additionally, the environmental impact results show that the total greenhouse gas emission for biomaterial production is 47–54 kg CO2eq/ton; however, the used biomaterials after water treatment can be sold for around USD 850 per ton as nutrient-rich soil conditioners. This study concluded that engineered biomaterials from lignocellulosic-based feedstocks could be a sustainable solution to the challenge that aquaculture faces, particularly capturing micronutrients from eutrophic water and reusing them as fertilizers.