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Antibiotics ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 68
Author(s):  
Chaoyue Zhang ◽  
Dan Wang ◽  
Weihong He ◽  
Hong Liu ◽  
Jianjun Chen ◽  
...  

Plant-based removal of nitrogen (N) and phosphorus (P) from water bodies is an important method for remediation of aquaculture wastewater. In order to acquire knowledge as to how antibiotic residues in wastewater might affect the microbial community and plant uptake of N and P, this study investigated N and P removal by a coastal plant Sesuvium portulacastrum L. grown in aquaculture wastewater treated with 0, 1, 5, or 50 mg/L sulfonamide antibiotics (sulfadiazine, SD) for 28 days and compared the microbial community structure between the water and rhizosphere. Results showed that SD significantly decreased N removal rates from 87.5% to 22.1% and total P removal rates from 99.6% to 85.5%. Plant fresh weights, root numbers, and moisture contents as well as activities of some enzymes in leaves were also reduced. SD changed the microbial community structure in water, but the microbial community structure in the rhizosphere was less affected by SD. The microbial diversity in water was higher than that in the rhizosphere, indicating microbial community differences. Our results showed that the commonly used antibiotic, SD, in aquaculture can inhibit plant growth, change the structure of microbial community, and reduce the capacity of S. portulacastrum plants to remove N and P from wastewater, and also raised alarm about detrimental effects of antibiotic residues in phytoremediation of wastewater.


2021 ◽  
Vol 12 (1) ◽  
pp. 227
Author(s):  
Youzhi Yu ◽  
Xu Li ◽  
Zhongjie Wang ◽  
Junfeng Rong ◽  
Kaixuan Wang ◽  
...  

Caprolactam wastewater (WCP), which is generated during the production of caprolactam, contains high contents of NO3− and inorganic P and is considered to be difficult to treat. In this study, Arthrospira platensis was used to remove N and P from WCP. Culture conditions and wastewater addition were optimized to relieve the inhibition effects of WCP. The results show that A. platensis growth and photosynthetic activity were inhibited depending on WCP concentrations. The inhibition rates were enhanced as the culture time increased under batch mode. However, the fed-batch mode significantly minimized the negative impact on A. platensis, which is beneficial for removing N and P from WCP by Arthrospira. After 10 d of cultivation of A. platensis in a 25 L circular photobioreactor in fed-batch addition of WCP (1.25% mixed WCP (v/v) each day), the average biomass productivity reached 17.48 g/(m2·d), the maximum protein content was 69.93%, and the N and P removal ratios were 100%. The accumulation effect of WCP inhibition on algal growth was not observed under this culture condition. Fed-batch cultivation of A. platensis is a promising way for bioremediation of WCP with high N and P removal efficiencies and high value-added biomass production.


Water ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 3
Author(s):  
Solvei Mundbjerg Jensen ◽  
Helmer Søhoel ◽  
Frances Helen Blaikie ◽  
Hans Brix ◽  
Carlos A. Arias

(1) Phosphorus (P) removal has proven difficult in decentralized wastewater treatment systems, and P binding material, installed as an external filter, has been proposed for improving P removal. Especially, calcium (Ca)-rich materials have shown promising results. (2) Five calcareous materials were tested with isotherm batch experiments. The material with the highest P adsorption capacity was selected to undergo different Sol-Gel coatings, i.e., different coating dilution ratios (1:10, 1:5, and 1:1) and exposure periods (5, 10, and 15 min). The seven coated materials were evaluated by isotherm experiments. (3) The maximum adsorption capacity (Qmax) was determined by fitting the Langmuir equation. Qmax for the non-coated materials, and ranged from 0.7 (sand) to 35.1 (Catsan) mg P g−1 DW, while the coated materials ranged from 7.8 to 24.7 mg P g−1 DW depending on the coating. Based on the rotated Principal Component Analysis, the most important parameters for Qmax were the texture and the Ca content. (4) Catsan was the most promising material, but when performing a Sol-Gel coating, a trade-off between preserving Qmax and the coating thickness were evident, as the materials with the thinner coating preserved more of the sorption capacity. The development of P binding materials constitutes a useful technology in decentralized wastewater treatment systems.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mansour Fazelipour ◽  
Afshin Takdastan ◽  
Seyed Mehdi Borghei ◽  
Neda Kiasat ◽  
Marcin Glodniok ◽  
...  

AbstractAn upgraded integrated fixed-film activated sludge-oxic settling anoxic (IFAS-OSA) system is a new technology for reducing nutrients and excess sludge. The results showed that the average TN removal efficiency of the IFAS-OSA system was gradually increased up to 7.5%, while the PO4–3-P removal efficiency increased up-to 27%, compared with that of the IFAS system. The COD removal efficiency of the IFAS-OSA system was slightly increased up-to 5.4% and TSS removal efficiency increased up to 10.5% compared with the control system. Biomass yield coefficient (Yobs) in the IFAS and IFAS-OSA systems were 0.44 and 0.24 (gr MLSS/ gr COD). Hence, sludge production decreased by 45%. The average SVI was decreased by 48% in IFAS-OSA system compared with IFAS. This study demonstrated the better performance of the IFAS-OSA system compared to that of the IFAS system.


Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3320
Author(s):  
Md. Aminur Rahman ◽  
Dane Lamb ◽  
Anitha Kunhikrishnan ◽  
Mohammad Mahmudur Rahman

Excessive discharge of phosphorus (P) to aquatic ecosystems can lead to unpleasant eutrophication phenomenon. Removal and recovery of P is challenging due to low C/N ratios in wastewater, hence the development of efficient removal and recovery of P strategies is essential. In this study, zirconium–iron (Zr–FeBC) and iron modified (Fe–BC) biosolid biochars were examined to investigate their capacity for the removal of P by batch experiments. The influence of solution pH, biochar dose, initial P concentration, ionic strength, interfering ions and temperature were also studied to evaluate the P adsorption performance of biochars. The P experimental data were best described with pseudo-second order kinetics and the Freundlich isotherm model. The maximum P adsorption capacities were reached to 33.33 and 25.71 mg g−1 for 24 h by Zr–FeBC and Fe-BC at pH 5 and 4, respectively. Desorption studies were performed to investigate the reusability, cost-effectiveness and stability of the adsorbents Zr–FeBC and Fe-BC. The adsorption–desorption study suggests that both examined biochars have considerable potentiality as adsorbent candidates in removing as well as recovery of P from wastewaters. Results also reveal that the regenerated Zr–FeBC and Fe–BC could be utilized repetitively in seven adsorption–desorption cycles using NaOH as a desorbing agent, which greatly reduces the P-removal cost from wastewaters. Thus, P enriched biochar could potentially be used as fertilizer in the agriculture sector.


2021 ◽  
Vol 11 (22) ◽  
pp. 10810
Author(s):  
Hui Luo ◽  
Baojie He ◽  
Wenhao Zhang ◽  
Zhaoqian Jing

Porous asphalt pavement (PAP) system is a widely used treatment measure in sustainable stormwater management and groundwater recharge, but their variable performance in nitrogen (N) and phosphorus (P) removal requires further reinforcement prior to widespread uptake. Two laboratory-scale PAP systems were developed by comparing limestone bedding and zeolite incorporated into modified zeolite powder porous microsphere (MZP-PM) as a filter column under a typical rainfall. The PAP system of zeolite bedding incorporated into MZP-PM (a weight less than 5% of zeolite) removed 74.5% to 90.6% of ammonium (NH4+-N) and 72.9% to 92.4% of total phosphate (TP) from the influent, as compared with 25.7% to 62.7% of NH4+-N and 32.6% to 56.4% of TP by that of the limestone as bed material. This improvement was presumably due to MZP-PM’s high adsorption capacity and surface complexation. The formation of ≡(La)(OH)PO2 was verified to be the dominant pathway for selective phosphate adsorption by MZP-PM and ion-exchange was proved to be the main removal process for ammonium. This study provides promising results for improving N and P removal by modifying a porous asphalt pavement system to include an MZP-PM adsorbent column as a post-treatment.


2021 ◽  
Vol 9 ◽  
Author(s):  
Wenjia Yu ◽  
Haigang Li ◽  
Peteh Mehdi Nkebiwe ◽  
Guohua Li ◽  
Torsten Müller ◽  
...  

Modern phosphate (P) fertilizers are sourced from P rock reserves, a finite and dwindling resource. Globally, China is the largest producer and consumer of P fertilizer and will deplete its domestic reserves within 80 years. It is necessary to avoid excess P input in agriculture through estimating P demand. We used the legacy P assessment model (LePA) to estimate P demand based on soil P management at the county, regional, and country scales according to six P application rate scenarios: (1) rate in 2012 maintained; (2) current rate maintained in low-P counties and P input stopped in high-P counties until critical Olsen-P level (CP) is reached, after which rate equals P-removal; (3) rate decreased to 1–1.5 kg ha−1 year−1 in low-P counties after CP is reached and in high-P counties; (4) rate in each county decreased to 1–8 kg ha−1 year−1 after soil Olsen-P reached CP in low P counties; (5) rate in each county was kept at P-removal rate after reduction; (6) P input was kept at the rate lower than P-offtake rate after reduction. The results showed that the total P fertilizer demand of China was 750 MT P2O5, 54% of P fertilizer can be saved from 2013 to 2080 in China, and soil Olsen-P of all counties can satisfy the demand for high crop yields. The greatest potential to decrease P input was in Yangtze Plain and South China, which reached 60%. Our results provide a firm basis to analyze the depletion of P reserves in other countries.


Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2883
Author(s):  
Rasa Vismontienė ◽  
Arvydas Povilaitis

Biochar has received increased attention in environmental applications in recent years. Therefore, three pilot-scale denitrifying bioreactors, one filled with woodchips only and the other two enriched with 10% and 20% by volume of biochar from deciduous wood, were tested under field conditions for the removal of nitrate (NO3-N) and phosphate (PO4-P) from tile drainage water in Lithuania over a 3-year period. The experiment showed the possibility to improve NO3-N removal by incorporating 20% biochar into woodchips. Compared to the woodchips only and woodchips amended with 10% biochar, the NO3-N removal effect was particularly higher at temperatures below 10.0 °C. The results also revealed that woodchips alone can be a suitable medium for PO4-P removal, while the amendment of biochar to woodchips (regardless of 10% or 20%) can lead to large releases of PO4-P and other elements. Due to the potential adverse effects, the use of biochar in woodchip bioreactors has proven to be very limited and complicated. The experiment highlighted the need to determine the retention capacity of biochar for relevant substances depending on the feedstock and its physical and chemical properties before using it in denitrifying bioreactors.


Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2745
Author(s):  
Jingyu Li ◽  
Guohua Cui ◽  
Yan Liu ◽  
Qiaohan Wang ◽  
Qingli Gong ◽  
...  

Seaweeds have been verified to effectively reduce the nutrients of aquaculture wastewater, and to increase the economic output when commercially valuable species are utilized. Pyropia/Porphyra/Neopyropia/Neoporphyra species are important seafood resources globally, and their growth and bioremediation capacities are affected by diverse biotic and abiotic stressors. In this study, we investigated the effects of desiccation (0, 1, 2, 4, and 6 h of air exposure), water velocity (0.1, 0.2, and 0.5 m s−1), and the nitrogen limitation period (1, 2, and 3 d) on the relative growth rates (RGR) and nutrient removal rates of Neoporphyrahaitanensis and Neoporphyradentata. The RGRs and NO3-N removal rates of the two species decreased significantly with increasing desiccation periods. A higher water velocity of 0.5 m s−1 had a greater negative impact on the RGRs and NO3-N and PO4-P removal rates than 0.1 and 0.2 m s−1. N. haitanensis exhibited a greater tolerance to water motion than N. dentata. Additionally, the RGRs and NO3-N and PO4-P removal rates were significantly different among the nitrogen limitation periods. N. haitanensis and N. dentata exhibited different nitrogen usage strategies after nitrogen limitation and recovery. These results provide valuable information relating to the excessive nutrient removal from aquaculture wastewater by Neoporphyra species.


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