Phosphate Removal Efficiency Research Articles

Removal of phosphate from synthetic wastewater: A comparative study between both activated clays using an experimental design methodology.

Phosphate-loaded industrial wastewaters have resulted in numerous environmental issues that have hard hit the Gulf of Gabes-Tunisia, making the environmental protection one of the most compelling priorities. Consequently, this study aimed first to compare the amounts of phosphate adsorbed by two types of Tunisian activated clays. The second goal was to assess and optimize the phosphate removal efficiency of these clays, using Box-Behnken design (BBD) under response surface methodology. Results showed that the highest adsorption amounts of 130.16 mg g-1 , 125.42 mg g-1 were yielded for Jebel Haidoudi clay and Douiret clay, respectively. These values demanded an initial phosphate concentration of 300 mg L-1 , a contact time of 5h, and a pH of 2). Thus, kinetic and isotherm studies of phosphate elimination from synthetic solutions demonstrated that for both activated clays, the pseudo-second-order and Langmuir equation fitted very well the experimental data, respectively. These results indicate that phosphate adsorption might be mainly a chimisorption phenomenon and a monolayer process. All these findings confirmed that both activated clays could be considered as a competent, cost-effective, efficient and ecological alternative for the elimination of phosphate from industrial wastewaters. PRACTITIONER POINTS: Activated clay could be adopted as an efficient and cost-effective adsorbent. The optimum conditions were nominated as 300 mg L-1 of initial phosphate concentration, 5 h contact times and pH=2. The probable uptake mechanism of phosphate followed predominantly the acid-base interaction and hydrogen bond.

Treatment of mariculture wastewater by an integrated ultrasonic stripping-membrane distillation (US-MD) system: Effect of operating parameters on effluent quality and membrane fouling mitigation

The actual application of membrane distillation (MD) in the mariculture industry is faced with two challenges of substandard ammonia removal and membrane fouling. Therefore, an integrated ultrasonic stripping (US)-MD system is built to efficiently purify mariculture wastewater in this study. US-MD technique exhibited outstanding purification for NH4+-N (86.8 %) compared to sole MD (76.2 %). US pretreatment coupled with a phase of setting ahead of MD could notably remove organics and salts from sewage, finally mitigating membrane fouling in subsequent MD (normalized flux (NF), 96.0 h, 0.77) compared sole MD (0.19). Ultrasonic cavitation effect in US unit largely promoted the protein denaturation and salt crystallization, causing a considerable removal efficiency for proteins (54.0 %∼68.8 %) and phosphate (7.1 %∼8.7 %) before MD unit. The operating parameters of US-MD system posed remarkable impacts on its purification efficiency, and proper increment of pH, operation time, and ultrasonic power in US unit partly facilitated the US-MD operation. US-MD operation was also enhanced by slightly raising the US temperature to around 35 °C. Furthermore, the higher temperature (80–90 °C) and flow velocity (10.48–15.72 mm/s) of feed in MD unit also contributed to the efficient purification of mariculture wastewater.

Lanthanum oxide-based nanomaterials synthesized by using carbon aerogel template for efficient phosphate capture

Phosphate is a chemical compound that contains phosphorus, an essential nutrient for the growth of all organisms on Earth. However, the overuse of fertilizers has created a serious environmental problem worldwide, because the discharge of wastewater containing excess phosphate leads to eutrophication. Therefore, proper management of phosphate from wastewater is very important. In this study, lanthanum oxide-based nanomaterials (LONs) were synthesized by a hard-template method using porous carbon aerogels, and their potential as adsorbents for efficient phosphate removal was evaluated. The use of carbon aerogels offers facile production of porous adsorbents because simple calcination under air can remove the template, which is more suitable for environmental and industrial applications than the use of toxic chemicals for conventional silica template removal. The morphology and porosity of the LONs were controlled by adjusting the synthesis conditions, including calcination and oxidation. The phosphate removal capacity of LONs strongly depends on the porous structure and surface area because the adsorption process is governed by monolayer adsorption of phosphate-forming lanthanum phosphate. LONs with an optimized structure exhibited a high adsorption capacity of 135.14 mg P g−1 at 28 °C (qm by the Langmuir isotherm model). LON adsorbents have great potential for efficient phosphate removal to meet increasingly stringent discharge standards and to prevent the pollution of water resources.

La(III) loaded Fe(III) cross–linked chitosan composites for efficient removal of phosphate from wastewater: Performance and mechanisms

The cost–effective removal and recovery of phosphate from wastewater is of great importance to controlling eutrophication and alleviating the phosphorus resource exhaustion crisis. Herein, chitosan (Cs) encapsulated bimetallic lanthanum (La) and iron (Fe) metal(hydro) oxides (La/Fe–Cs) composites were fabricated using a co–precipitated method for enhanced phosphate removal and recovery. The La/Fe–Cs composites had rough and raised spongy–like surfaces coated with La/Fe (hydr)oxide particles with a high specific surface area of 109.84 m2 g−1, providing more potential binding sites for phosphate capture. The La/Fe–Cs composites with a 1:2 La–to–Fe molar ratio exhibited a maximum adsorption capacity of 67.52 mg g−1 for phosphate at 308 K, calculated using the Langmuir model, which was 211% higher than that of monometallic Fe–Cs composites. Meanwhile, this composite also showed a high phosphate removal rate (63–95%) in an extensive applicable pH range (3.00–10.00) and rapid adsorption within 10 min (up to 94%). Moreover, the adsorption of phosphate by La/Fe–Cs composites was mildly disturbed against co–existing ions of NO3−, Cl−, and humic acid, while adsorption capacities were reduced by almost 13–45% with the existence of SO42−, HCO3−, and CO32−. The FTIR, XPS, and DFT results suggested that La–doped facilitated phosphate removal and the predominant mechanisms involved electrostatic interaction, surface precipitation, and inner–sphere complexation processes. Additionally, La/Fe–Cs composites also illustrated excellent efficiencies in simultaneous scavenging phosphate and ammonia from eutrophication and poultry wastewater. These results highlight bimetallic La/Fe–Cs composites are promising candidates for efficient elimination and recovery of phosphate from real wastewater, and subsequently could be used as slow–release fertilizers or soil amendments.

The modification of biomass waste by cerium-based MOFs for efficient phosphate removal: excellent performance and reaction mechanism.

Due to the possibility of causing eutrophication, excessive phosphate discharged into water bodies always threatens the stabilization of aquatic ecosystem. A promising strategy is to remove phosphate from water by the utilization of biomass waste as adsorbents. In this paper, the corn straw (CS) and pine sawdust (PS) are chosen for adsorption; however, the phosphate removal capacities of them are very limited. Considering the high phosphate uptake of trivalent cerium, Ce (III)-based nanoparticles (CD and CT) are selected to be loaded on the biomass by hydrothermal synthesis to obtain four modified materials. CD is metal organic frameworks (MOFs) with Ce5(BDC)7.5(DMF)4 as its molecular structure, while CT is MOFs derivatives with [Ce (HCOO)]n as its crystal structure. The adsorption capacities of CS-CD, PS-CD, CS-CT and PS-CT reach 181.38, 183.27, 225.55 and 186.23 mg/g. But on account of the different molecular structures, CS-CD and PS-CD achieve great phosphate uptake under wide applicable scope of pH from 2 to 11, whereas CS-CT and PS-CT only under acidic conditions. The analysis of the adsorption mechanism indicates that due to the unsaturated coordination bond of CD, it could remove phosphate through coprecipitation and ion exchange even under alkaline conditions.

Magnesium chloride-modified potassium humate-based carbon material for efficient removal of phosphate from water

BackgroundTo solve the problem of eutrophication caused by phosphate, a metal-loaded biocarbon composite material is considered to be an effective adsorbent for removing phosphate. MethodsIn this study, potassium humate was used to prepare modified potassium humate-based carbon material (MPHCM) through magnesium chloride modification and rapid pyrolysis. Significant findingsStudies have shown that MPHCM can effectively remove phosphate from water. At 318 K and with pH=3, the maximum adsorption capacity reached 181.96 mg P g−1, and the adsorption process conformed to the pseudo-first and pseudo-secondary adsorption kinetic models and the Langmuir adsorption model. This adsorption process involved physical and chemical adsorption, which indicated monolayer adsorption. The main adsorption mechanisms for MPHCM were protonation, electrostatic interactions, ligand exchange and inner sphere complex precipitation. Six desorption cycles verified the excellent reproducibility of MPHCM for phosphate removal. Therefore, this study provides a new adsorbent for phosphate removal and expands the application range of potassium humate-based carbon materials.

Industrial steel waste-based adsorbent: An effective phosphate removal from aqueous media

This work offers the alternative to mitigate the problem of eutrophication of water bodies that can result in a serious threat to environment and aquatic life by using steel wastes for phosphate removal. Produced on the scale of thousands of tons per year, these wastes can contribute to air, soil, and water pollution when discharged without a proper management. In this context, this work evaluates the potential of phosphate remediation by adsorption applying steel industry wastes, addressing two important environmental problems at once. For the first time, blast furnace sludge (BFS) and the powder from Kanbara reactor (KR) without pre-treatment were used for the elucidation of the removal mechanism of phosphate, employing the method of sequential extractions, kinetic studies, and thermodynamics. The chemical and structural analyses demonstrated the materials present an irregular morphology with most of the pores in the mesopore range being mainly composed by alkali metals and metal oxides. Although approximately 99% of phosphate removal efficiency was reached for both wastes in 24 h, the speciation studies showed phosphate and KR interacts too strongly making its reuse hardly feasible and therefore not suitable from a practical point of view. For BFS, on the contrary, the thermodynamic data indicated a physisorption process offering the advantage of reutilization. In addition, about 97% of phosphate removal is achieved during the first 10 min of adsorption, regardless the solution pH, thus offering good prospects in aggregating value to steel industry wastes as adsorbents being in line with a sustainable economy.

Ecological restoration for the Liangtan river by Rotating biological contactors combined with hybrid constructed wetlands

Rotating biological contactors (RBCs) were first used as pretreatment units for hybrid constructed wetlands (HCWs) in practical engineering to treat polluted river water. The experimental results during 2019–2021, except the period of global COVID-19 pandemic (January to April, November and December in 2020), indicated the average removal efficiencies of ammonia nitrogen (NH4+–N), total phosphorous (TP), and chemical oxygen demand (COD) were 95.06%, 41.03%, and 45.46%, which met the Chinese Environmental Quality Standards Ⅰ, Ⅲ, Ⅳ (CEQS Ⅰ, Ⅲ, Ⅳ), respectively. RBCs and HCWs had synergistic and complementary effects on purification efficiency, especially on nitrogen removal. The remarkable nitrification efficiency of RBCs was not influenced by temperature and influent loads. The relative abundances of microorganisms at HCWs in cold seasons were comparable to that in warm seasons, which promoted the recovery of decontamination efficiency after overwintering. These results support RBCs combined with HCWs (R-HCWs) is an effective polluted river purification process, providing a new perspective on water ecological restoration.

Long-term exposure to nanoplastics reshapes the microbial interaction network of activated sludge

Wastewater treatment plants have been identified as an important gathering spot for nanoplastics, possibly having unintended impacts on important biological nutrient removal processes. The underlying effects of long-term exposure of activated sludge to nanoplastics on nutrient removal and the mechanisms involved remain unclear. This study investigated the effect of polystyrene nanoplastics (Nano-PS) on the treatment performance and microbial community structure, and network in activated sludge. The results indicate that 1000 μg/L Nano-PS had chronic negative effects on the treatment performance in a continuous test over 140 days. Nano-PS had no significant impact in the earlier stages (0–50 days). However, as exposure time increased, the removal efficiencies of chemical oxygen demand, total phosphorous, and total nitrogen (TN) decreased by 2.7, 33.2, and 23.5%, respectively, in the later stages (87–132 days). These adverse impacts further manifested as a change in the topological characteristics, forming a smaller scale, lower complexity, and weaker transfer efficiency of the microbial network. Moreover, the scale and complexity of subnetwork-nitrogen removal bacteria and subnetwork-nitrifier were inhibited, leading to an increase in the effluent TN and NH4+-N. The decreased modules and connectors (keystone taxa) likely caused the deterioration of treatment performance and functional diversity, which was consistent with the change in PICRUSt results. Less competition, denser nodes, and more complex module structures were induced as a strategy to mediate the long-term stress of nano-PS. To our knowledge, this is the first attempt to explore the long-term effects of nano-PS on the microbial interaction network of activated sludge, laying an experimental foundation for reducing the risks associated with nanoplastics.

Investigation of selected physico-chemical quality parameters in industrial wastewater by electrocoagulation process, Ethiopia

Nowadays, there are more than fourteen major state and private owned textile industries and garment factories in Ethiopia. However, these textile effluents are directly discharged without treatment to the surrounding environment, as a result, the pollutants bring serious problem to the surrounding community including health such as skin diseases, asthma, abortion, carcinogenic effect, biodiversity loss and mutagenic effect on the. The main objective of this study is characterization and treatment of the textile effluent using aluminum electrodes in the electrocoagulation process. EC experimental setups were designed and different parameters were optimized. Electrocoagulation treatment process eliminates physicochemical quality indicators such as pH, electrical conductivity (EC); turbidity, biological oxygen demand (BOD), ammonia; nitrate, nitrite, total nitrogen (TN) and phosphate were determined using standard procedures. From the result, the maximum removal efficiency of phosphate, ammonia, TN, electrical conductivity, turbidity and BOD were obtained 97, 87, 88, 89, 99 and 66%, respectively. Analyses of the electrochemically generated sludge by X-ray Diffraction, Scanning Electron Microscope (SEM), and Fourier Transform Infrared Spectroscopy (FTIR) revealed that the expected crystalline aluminum oxides (bayerite (Al(OH)3 diaspore (AlO(OH)) were found in the sludge. The amorphous phase was also found in the floc. Therefore, a treatment technology was good and encourages the community to apply the technique for the treatment of textile effluent before discharging into the environment.

Impact of nitrite and oxygen on nitrous oxide emissions from a granular sludge sequencing batch reactor

Maximizing nutrient removal and minimizing greenhouse gas (GHG) emissions is imperative for the future of wastewater treatment. As municipalities focus on minimizing their carbon footprints, future permits could regulate GHG emissions from wastewater treatment plants. This study investigates how nitrous oxide (N2O) emissions are affected by dissolved oxygen and nitrite concentrations, providing potential strategies to meet possible gaseous emission permits. A lab-scale sequencing batch reactor (SBR) was enriched with aerobic granular sludge (AGS) capable of phosphate removal and simultaneous nitrification-denitrification (SND). N2O emissions were tracked at varying dissolved oxygen (DO) and nitrite (NO2−) concentrations, with >99% SND efficiency and 93%–100% phosphate removal efficiency. Higher DO and NO2− concentrations were associated with higher N2O emissions. Emissions were minimized at a DO concentration of 1 mg L−1, with an average emission factor of 0.18% of oxidized NH3–N emitted as N2O–N, which is lower than factors from many full-scale treatment plants (Vasilaki et al., 2019) and similar to a Nereda® full-scale AGS SBR (van Dijk et al., 2021). This challenges assertions that AGS emits more N2O than conventional activated sludge, although more research at full-scale with influent quality variations is required to confirm this trend. Molecular analyses revealed that the efficient SND was likely achieved with shortcut nitrogen removal facilitated by a low presence of nitrite oxidizing bacteria and a large population of denitrifying phosphate accumulating organisms, which far outnumbered denitrifying glycogen accumulating organisms.

Urban runoff quality and quantity control: a functional comparison of various types of detention basins

ABSTRACT Hydraulic behavior and pollutant removal efficiency of three stormwater end-of-pipe control structures were evaluated and compared. Three detention basins (wet, dry, and semi-dry, i.e. dry with a wet central channel) were monitored within three sites of Southern Quebec, Canada. Water samples were collected upstream and downstream of the basins and analyzed for total suspended solids (TSS), nitrogen, total phosphorous, and ions related to de-icing salts. Generalized linear models and hydrological/hydraulic (SWMM) models were developed to compute the long-term TSS and total phosphorous load removal efficiency for two of the studied basins. Results indicate that even when considering uncertainties, removal rates are the highest for the wet basin and the lowest for the dry one. The addition of a wet channel in the semi-dry basin leads to higher removal efficiency than in the dry basin (e.g. median TSS concentration removal of 69% and 14%, respectively, for the semi-dry and dry basins).

Improving the phosphate adsorption performance of layered manganese oxide by ammonia plasma surface modification

The introduction of excessive phosphate to natural water bodies often results in serious eutrophication. Adsorption is thought to be one of the best methods for phosphate recovery and removal from water. The abundance of surface functional groups and high particular surface part of layered manganese oxide (LMO) makes it an ideal agent to remove pollutants from wastewater. However, since the surface of LMO is normally negatively charged at neutral pH, it cannot efficiently clear anionic contaminants like phosphate. This study brings forward a novel development of phosphate sorbents that help remove phosphate from water. Specifically, the modification of LMO with plasma technology in the presence of ammonia (NH3) has yielded promising results. These outcomes indicated that NH3-LMO exhibited an ultrathin and transparent layered structure with numerous graphene-like wrinkles and folds. The adsorption of phosphate by NH3-LMO was very fast and followed pseudo-second-order kinetics. Due to the uniform distribution of adsorption sites on the surface of NH3-LMO, the Langmuir isotherm model could clearly support the phosphate adsorption onto NH3-LMO. The presence of chloride, sulfate, nitrate, and dissolved humic acid exerted a slight influence on the phosphate removal efficiency of NH3-LMO. Furthermore, the adsorption of phosphate by NH3-LMO was highly pH-dependent. This is mainly attributed to the transformation of pHIEP from 2.2 for LMO to 6.6 for NH3-LMO, which is positively charged at neutral pH. For the NH3-LMO reuse, the adsorption function was relatively stable after four adsorption-desorption cycles. Collectively, our research showed that NH3-LMO could be adopted as a potential adsorbent for the phosphate removal from water.

Facile synthesis of hydrous zirconia-impregnated chitosan beads as a filter medium for efficient removal of phosphate from water

The removal and recovery of phosphate from water using adsorption technology require that the adsorbent material is easily separable from treated water. Continuous efforts are still awaited to develop additional efficient phosphate adsorbents that are economical to fabricate. In this study, hydrous zirconia-impregnated chitosan beads (HZCB) containing different Zr/chitosan ratios were synthesized using a facile scheme. We found that HZCB with a Zr/amine molar ratio of ~ 1 (HZCB-1) possessed excellent stability and phosphate removal performance. This optimized material was characterized with XRD, SEM, FTIR, XPS, specific surface area and point of zero charge measurements. The maximum adsorption capacity was 42.02 mg/g (at pH ~ 6.7). The adsorption kinetics were best described by a pseudosecond-order model, and the rate constant of HZCB-1 was much lower than that of its powder but was similar to the commercial bead product Ferrolox. The removal of phosphate depended substantially upon pH and was enhanced by lowering the pH. Good selectivity of HZCB-1 for phosphate was observed, although the coexistence of sulfate produced a significant negative effect. Direct coordination of phosphate to Zr atoms by replacing hydroxyls was the dominant adsorption mechanism (~ 85%), while chitosan also contributed to phosphate removal (~ 15%). Adsorbed phosphate was successfully eluted by an NaOH solution, and the material obtained after desorption and regeneration was able to be repeatedly used. The results of column studies indicated that this material could be implemented in long-term application.

Enhanced removal of phosphate by electrogenerated iron combined with mechanically activated calcite

Fe electrocoagulation is efficient for the removal of phosphate with low energy consumption, whereas suffers from the high concentrations of the total dissolved Fe (TDFe) in the effluent. In this study, mechanically activated calcite was used to combine with the electrogenerated Fe to improve the removal efficiency of phosphate and reduce the concentrations of TDFe. The removal efficiency of phosphate (initial concentration 1.0 mg/L) in 30 min was significantly increased (88 %) by mechanically activated calcite combined with electrogenerated Fe method, compared with mechanically activated calcite method (43 %) and electrogenerated Fe method (53 %) separately. The concentration of TDFe in the effluent reduced from 4.9 mg/L with electrogenerated Fe method to 0.2 ∼ 0.5 mg/L with mechanically activated calcite combined with the electrogenerated Fe method. The mechanically activated calcite combined with electrogenerated Fe method was confirmed by the efficient removal of phosphate in the biological treatment effluent from a municipal wastewater treatment plant reached a removal efficiency of approximately 100 % (reduced from 1.33 mg/L to 0.006 mg/L) and in the rainfall runoff from a fertilizer enterprise reached a removal efficiency of 98 % (reduced from 3.86 mg/L to 0.075 mg/L). The removal mechanism was proposed. The Fe-P polymer was formed in the dissolved phase. The mechanical activation improved the solubility of calcite and provided dissolved Ca2+, as well as increased the surface area of calcite and provided more adsorption sites. Therefore, the mechanical activation promoted the adsorption of the Fe-P polymer onto the surface of the mechanically activated calcite. This study provided an efficient method for the removal of phosphate in wastewater and simultaneously reducing the concentrations of TDFe in the effluent.

Recovery of Fe from steel pickling wastewater as polymeric Fe/S rods for effective adsorption of phosphate from electrophoresis effluent

Pickling wastewater is rich in Fe(II) and commonly neutralised by limestone to precipitate Fe as waste Fe-rich sludge. Herein, an alternative reutilisation route was developed to recycle Fe from pickling wastewater as polymeric Fe/S rods for the effective removal of phosphate from the actual electrophoresis effluent. Results showed that irregular ferrous oxyhydroxide predominated in the precipitated sludge after the direct neutralisation of wastewater and was then converted into coarse spherical particles after alkaline heating at 80 °C for 24 h under atmospheric condition. After adding nitrite to oxide Fe(II) in pickling wastewater, ferric oxyhydroxide and magnetite were formed in the sludge and were converted into polymeric Fe/S-bearing rods with the same procedure. The rods had a one-dimensional polymeric (FeS2)nn- structure of KFeS2 crystal with 200 nm diameter and 2–5 μm length and was spontaneously hydrolysed in pH range of 3–9 to fine colloids with abundant hydroxyl/sulfhydryl groups. The optimal dosage of polymeric Fe/S-bearing rods was 10 g/L, where the phosphate removal was 99.6 %, and the remaining phosphate was only 0.47 mg/L in the treated electrophoresis effluent. During the KFeS2 rods synthesis, an alkaline supernatant was generated, but was recycled to prepare rods in the next round, and the prepared rods also showed high removal efficiency of phosphate. For instance, by adding 6.67 g/L prepared rods, the phosphate removal achieved by 94.5 %, approximated to that of fresh one (95.3 %). In summary, Fe was recycled from pickling wastewater as polymeric Fe/S-bearing rods without generating any secondary waste and the rods were effective in the treatment of phosphate-rich wastewater.

Tuning the lanthanum hydrolysis induced assembly process using long linear chains with –N+(CH3)3 groups for efficient phosphate removal

Lanthanum composites are known for their specific interactions with phosphorus (ortho-P), which when combined with high-surface-charge matrix materials, makes them promising candidates for P adsorbents. Here, we have described an attempt to achieve an ideal lanthanum hydrolysis-induced assembly in a cellulose hydrogel network by regulating the spatial distribution of –N+(CH3)3 groups on the polymer chains, thereby improving the dispersion of La(OH)3 clusters in the matrices. A P adsorption capacity of 92.54 mg/g with a molar P/La ratio of 1.41 was observed in a composite consisting of 37.58 % –N+(CH3)3 in a hydrogel, namely, lanthanum loaded cellulose cationic hydrogel (CCH@La). CCH@La exhibited a wide applicable scope of pH ranging from 3.0 to 9.0 and a good selectivity in the presence of co-existing substances. After five regeneration cycles, the adsorption amount of regenerated CCH@La still remained at 80.74 % of its maximum value. The maximum La(OH)3 usage efficiency of CCH@La with –N+(CH3)3 grafted polymer chains was estimated to be 2.01 folds of that in the –COO– grafted lanthanum loaded cellulose anionic hydrogel (CAH@La), underlining the role of tuning the space charge distribution for metal hydroxide dispersion in hydrogel systems. This allows for the synergistic effect of electrostatic attraction and La–P coordination produced by the ideally dispersed La(OH)3 clusters in the network of hydrogels, thereby facilitating P adsorption. After adsorption, the main adsorbed P species in CCH@La were inner-sphere complex on the surface of La(OH)3 particles as well as the LaPO4·xH2O crystallite.

THE REDUCING OF ORGANIC LOADING AND PHOSPHATE (PO4) IN DOMESTIC WASTEWATER TREATMENT BY CONSTRUCTED WETLAND SYSTEM USING CANNA INDICA AND CYPERUS ALTERNIFOLIUS

The domestic wastewater is mostly produced in settlement areas and usually directly discharged into the environment. Its high organic matter and nutrients will pollute the environment. As an alternative, one of the good wastewater treatment systems is the Sub Surface Flow Constructed Wetland. This system has some advantages such as easy implementation, low cost, and doesn’t need a large area. The aim of this study is to determine the efficiency of Canna indica and Cyperus alternifolius to reduce organic matter and phosphate. This study is an experimental study with two treatments (T1: SSF CW with Canna indica; T2: SSF CW with Cyperus alternifolius). The SSF CW system contains gravels those diameters are 3-5 cm, 1-3 cm, and <1 cm, as well as paddy soil as media with HRT of 3 days. The parameters measured included temperature, BOD, DO, PO4, and pH. Based on this study, it can be concluded that the higher removal efficiency of organic matter is shown by the CW SSF system with Cyperus alternifolius. It is 48,86% in T2 and 42,69% in T1. While the removal efficiency of phosphate in T1 and T2 are 65,70% and 67,21% respectively.

Simultaneous Treatment of Swine and Furfural Wastewater Integrated with Lipid Production of Chlorella pyrenoidosa

Adding organic compounds to wastewater can improve the carbon/nitrogen ratio and benefit microalgae growth. We studied microalgal growth, nutrient removal and lipid accumulation of Chlorella pyrenoidosa cultured in a mixture of swine wastewater (SW) and furfural wastewater (FW). The mix ratio of SW:DFW (diluted furfural wastewater) had a significant effect on microalgae growth. As the mix ratio of SW:DFW decreased from 1:0.5 to 1:19, the maximum microalgal biomass increased, while the specific growth rate initially increased and then decreased. The efficiency of nutrient removal also depended on the mix ratio of wastewater. The highest chemical oxygen demand (COD) removal efficiency (57.30%) occurred at the mix ratio of SW:DFW = 1:3. The highest removal efficiencies of total phosphorous (TP) reached 61.93% when the mix ratio of SW:DFW was 1:9. Wastewater at the mix ratio of SW:DFW = 1:19 had a maximum lipid productivity of 49.48 mg L−1 d−1, which was 4.9 times higher than that at a mix ratio of SW:DFW = 1:0.5. These results showed that C. pyrenoidosa can be used to remove nutrients from mixed wastewater sources and simultaneously produce algal lipids.

Performance evaluation of different macrophytes in small‐scale vertical flow constructed wetlands for greywater treatment using principal component analysis

AbstractThe scarcity of water is perceived as a systematic global risk due to increasing water demand. Vertical flow constructed wetland (VFCW) is proposed as an energetically efficient and economical process to treat greywater (GW) for non‐potable purposes. Macrophyte contributes a significant amount to the treatment process, and it depends on species, and their ecology. In this study, four single‐stage VFCW systems were planted with locally available plant species named Hymenocallis littoralis as Plant 1, Phragmites australis as Plant 2, Canna indica Plant as 3, and Colocasia as Plant 4, which were used for the treatment of GW. The mean removal efficiencies associated with Plant 1, Plant 2, Plant 3, and Plant 4 are 55.13%, 48.11%, 52.53%, and 56.39% for chemical oxygen demand (COD); 45.35%, 35.36%, 64.10%, and 56.39% for ammonia; and 32.97%, 20.85%, 71.57%, and 33.40% for phosphate, respectively. All systems show significant removal efficiency (more than 40%) of all pollutants, except TDS and pH. Among all the observed plants, C. indica achieved the highest removal efficiency for COD, ammonia, and phosphate. The obtained results were analyzed for the dependency of correlations with effluent, influent, and macrophytes used in the treatment system. The principal component analysis (PCA) identified two principal components from 13 variables and explained 50.25%, 47.47%, and 45.62% variance of normalized datasets in VFCW. The PCA also shows significant correlations of plant species with different targeted effluent parameters.