SCIENCE OF THE TOTAL ENVIRONMENT
·
2020
·
IF 6.551
Xingwen Lu,Zebiao Huang,Zhihong Liang,Zhe Li,Jiani Yang,Yujie Wang,Fei Wang
Struvite recovered from wastewater can be used as a slow-release fertilizer. Nevertheless, hazardous metals easily precipitated with struvite would increase the ecological risk for its agricultural use. In this study, the influence of individual and coexistence of Cu and Zn on the precipitation of struvite was investigated. The loading of Cu and/or Zn in precipitates increased with the increase of initial metal concentrations (0.1–100 mg/L). Quantitative X-ray diffraction (QXRD) analysis revealed that the increase of Cu and/or Zn level in reaction solution disturbed crystal growth of struvite and promoted the formation of amorphous phase(s). Scanning electron microscopy (SEM) revealed the pit formation on struvite crystal surfaces, combined with X-ray photoelectron spectroscopy (XPS) data, the results indicated a surface interaction for the formation of Cu-OH and Cu-NH 3 on struvite surface at Cu of 0.1–10 mg/L. With the increase of Cu to 25–100 mg/L, the precipitation of amorphous Cu phosphate(s) was confirmed by XPS and QXRD. At Zn of 0.1–10 mg/L, the enrichment of Zn-PO 4 and Zn-OH on struvite surface was observed, whereas, the precipitation of amorphous Zn hydroxide(s) was confirmed at Zn of 25–100 mg/L. At Cu and Zn co-existed solution, the decrease of Cu-PO 4 and increase of Zn-PO 4 suggested the competitive binding of PO 4 between Cu and Zn. In addition, the formation of amorphous Mg hydroxide(s) and phosphate(s) was detected regardless of the addition of Cu in solutions. The overall results revealed that the existence of Cu and Zn during struvite formation can greatly affect its content by formation of different metal-containing products.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Xingwen Lu,Wang Xu,Qinghuai Zeng,Weizhen Liu,Fei Wang
Struvite precipitation is a promising strategy for the simultaneous recovery of nitrogen and phosphorus from waste streams. However, waste streams typically contain high amounts of metal contaminants, including Ni, which can be easily sequestered by struvite, but the behavior of Ni during struvite precipitation remains unclear. Thus, this study investigates the influence of Ni concentrations on struvite precipitation. The quantitative X-ray diffraction (QXRD) results revealed that the purity of struvite decreased from 96.6 to 41.1% with the Ni concentrations increased from 0.1–100 mg·L −1 . At lower Ni concentrations of 0.1–1 mg·L −1 , scanning electron microscopy (SEM) showed a roughened surface of struvite crystal, and this was combined with X-ray absorption near edge structure (XANES) data that indicated a stack of Ni-OH and Ni-PO 4 on struvite surface. At Ni concentrations of 10–25 mg·L −1 , Ni primarily crystalized as Ni-struvite (NiNH 4 PO 4 ·6H 2 O), as detected by QXRD. At higher Ni concentrations of 25–100 mg·L −1 , the co-precipitation of amorphous Ni phosphate(s) (e.g., Ni 3 (PO 4 ) 2 ) and Ni hydroxide (e.g., Ni(OH) 2 ) was identified by XANES. Specifically, the X-ray photoelectron spectroscopy (XPS) analysis detected the formation of amorphous Mg hydroxide(s) and phosphate(s) at Ni of 25–100 mg·L −1 . The overall results revealed that Ni formed Ni-OH and Ni-PO 4 on struvite surface at 0.1–1 mg·L −1 , whereas Ni precipitated as separated phases (e.g. Ni-struvite, Ni hydroxide and phosphate) at 10–100 mg·L −1 . The existence of Ni disturbed the crystal growth of struvite and promoted the formation of Ni-struvite, amorphous products during struvite formation.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING RESEARCH & DESIGN
·
2023
·
IF 3.9
Guangyuan Chen,Meng Zhang,Tong Zhou,Zhongxiang Ding,Haiying Tang,Yuanhui Ji,Changsong Wang
Struvite (MgNH 4 PO 4 ·6 H 2 O，MAP), a type of high-quality, slow-release fertilizer, is the main component of urinary stones in animals and humans and causes scale formation in industrial pipes. Therefore, MAP dissolution is an important research topic. Herein, MAP dissolution experiments are performed and a thermodynamic model is developed to evaluate the influences of pH, temperature ( T ), and particle size ( P s ) on surface reaction resistance ( 1/k s ) and diffusion resistance ( 1/k d ). The results show that MAP solubility decreases with an increase in pH and the effects of pH change are more obvious than those of T or P s . The total resistance ( 1/k T ) of MAP dissolution increases with pH increase, P s growth, or T reduction. The comparison of 1/k s and 1/k d reveals surface reaction as the MAP dissolution control step and indicates a linear relation among 1/k s , 1/k d , and the natural logarithm of P s at pH 7.0.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Communications
·
2023
·
IF 3.8
Zilong Liang,Jingxuan Liu,Yange Wan,Zhaojie Feng,Pengyu Zhang,Mingchao Wang,Haijun Zhang
Struvite is a common adverse waste in sewage treatment plants. To evaluate the feasibility of struvite as an extinguishing agent, a novel DOPO-VTS (vinyltrimethoxysilane and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxa) modified struvite ultra-fine powder with stable performance was prepared using an economic synthesis method, and the extinguishing property and mechanism were deeply analyzed. The local oil basin test showed that the fire extinguishing effect of DOPO-VTS modified struvite was significantly better than that of commercial ABC (NH 4 H 2 PO 4 ) dry powder and blank struvite without modification. By coating DOPO-VTS on struvite, the original agglomeration problem was solved, and the liquidity index (angle of repose) was 34 °, better than ABC (NH 4 H 2 PO 4 ) dry powder (37 °) and blank struvite (40 °). Besides, under the protection of DOPO-VTS, the overall thermal stability and hydrophobic effect were also improved. The DOPO-VTS modified struvite could maintain fire extinguishing activity at a temperature close to 100 ℃, 40 ℃ higher than blank struvite, which not only widened its storage environment, but also helped to extinguish the fire at the root of the flame. Furthermore, a large number of P-O groups were generated during the pyrolysis of DOPO-VTS modified struvite, greatly improving its fire extinguishing performance. In addition, the physicochemical reaction during the extinguishing process, including heat absorption/release, particle size distribution , composition, and structural evolution, and gas phase product analysis, were comprehensively studied. Combined with the fire extinguishing experiment results, temperature,and smoke changes, three kinds of extinguishing mechanisms were confirmed: cooling effect, asphyxiation, and chemical effect.
研究领域:
材料科学
·
消防工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Xinyue Liu,Yongyu Ren,Zengqi Zhang,Xiaoming Liu,Yaguang Wang
The ammonia nitrogen in electrolytic manganese residue (EMR) is easily transferred to water source, polluting the environment and endangering biological health. In this study, the ammonia nitrogen in EMR is removed by slaked lime, carbide slag (CS) and red mud (RM). The removal of ammonia nitrogen is influenced by the liquid–solid ratio, stirring time, and additives dosage. The removal efficiency of ammonia nitrogen of EMR pretreated with 7.4 % fresh CS for 15 min can reach 98.5 % when the liquid–solid ratio is 1.50. Under the synergistic effect of CS and RM, the ammonia nitrogen in EMR is quickly removed within 15 min, and the removal efficiency of ammonia nitrogen reaches 98.2 %. It is feasible to replace slaked lime with CS and RM to achieve the removal of ammonia nitrogen in EMR. Struvite has high quantity and good purity when the molar ratio of N, P and Mg is 1:1.6:1.6 and pH = 8.0. The remaining EMR after removal of ammonia nitrogen, blast furnace slag, Portland cement and aggregates was used as raw materials to prepare nonsintered bricks (NSB). The NSB according to the optimal formula after curing for 7 days had no free ammonia nitrogen detected. This study provided a new way to remove ammonium nitrogen in EMR by CS and RM, and demonstrated a solution to prepare struvite and nonsintered bricks.
研究领域:
环境科学
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材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2023
·
IF 8.8
Xingwen Lu,Jiating Li,Wang Xu,Zenghua Qi,Fei Wang
During the struvite recovery process, Cd, a hazardous metal commonly found in waste streams, can be sequestered by struvite. This study investigated the influence of Cd 2+ on the precipitation of struvite. Quantitative X-ray diffraction (QXRD) results showed that the purity of struvite decreased from 99.1% to 73.6% as Cd concentration increased from 1 to 500 μM. Scanning electron microscopy (SEM) revealed a roughened surface of struvite, and X-ray photoelectron spectroscopy (XPS) analysis indicated that the peak area ratio of Cd–OH increased from 19.4% to 51.3%, while the area ratio of Cd-PO 4 decreased from 86.6% to 48.7% as Cd concentrations increased from 10 to 500 μM. The findings suggested that Cd 2+ disrupted the crystal growth of struvite, and mainly combined with –OH and -PO 4 to form amorphous Cd-bearing compounds co-precipitated with struvite. Additionally, Mg-containing amorphous phases were formed by incorporating Mg 2+ with –OH and -PO 4 during struvite formation.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Cleaner Production
·
2017
·
IF 5.715
Xiaochang Lin,Zhiying Han,Hongjun Yu,Zhangying Ye,Songming Zhu,Jun Zhu
A novel, two-chamber electrolysis cell equipped with an ion exchange membrane and a magnesium anode was proposed in this study to recover phosphate as struvite from both the simulated and real biogas digestion slurry of swine wastewater. In the electrolysis experiments with the simulated slurry, the optimal pH and current density were determined to be 8.5 and 22.2 A m −2 , respectively, achieving 95% phosphate removal efficiency and 100% current efficiency. The phosphate removal rate was mainly dependent on the magnesium dissolving rate. In the electrolysis experiments with the real digestion slurry, the pH of slurry increased from 7.4 to around 8.7 after the cathode-anode sub-section electrolysis without adding chemical reagents, achieving 93% phosphate removal efficiency at 22.2 A m −2 . The phosphate removal efficiency could be kept constant in three consecutive electrolysis cycles with both the anion exchange membrane and the cation exchange membrane . The cost of the magnesium anode treatment for the real biogas digestion slurry for struvite recovery was estimated to be $81.57 kg −1 P, mainly resulting from the consumption of electricity and magnesium anode. The precipitates collected from all experiments were identified as struvite by the X-ray diffraction analysis.
研究领域:
环境科学
·
废水处理
✓ 已验证
DOI
高影响因子
Journal of Cleaner Production
·
2021
·
IF 9.297
Qian Guan,Guisheng Zeng,Baichuan Gong,Yingpeng Li,Haiyan Ji,Jiefei Zhang,Jiatian Song,Chunli Liu,Zhongbing Wang,Chunjian Deng
Swine wastewater contains phosphorus, ammonia nitrogen, and heavy metals that affect the struvite purity produced from the wastewater and increase the ecological hazards. In addition, struvite crystallization process is highly dependent on the usage of magnesium sources. Thus, it is necessary to explore the effects of three magnesium sources, including MgCl 2 , Mg(OH) 2 and MgO , on the phosphorus recovery and minimizing Cu and Fe contents via struvite crystallization process. The observations revealed that the predominant parts of Cu and Fe precipitate in the form of hydroxide during pH adjustment. Meanwhile, when using MgCl 2 as the magnesium source, the optimal removal efficiency of phosphorus reached 94.55%, followed by MgO and Mg(OH) 2 . Simultaneously, 90.60% Cu and 98.80% Fe precipitate under MgCl 2 as magnesium source. The redissolution behavior of Cu occurs when MgO and Mg(OH) 2 are used as magnesium sources, increasing the Cu concentration. The smallest operation cost is from MgCl 2 as magnesium source. The potential environmental impact analyzed by life cycle assessment method shows that MgCl 2 in struvite crystallization process saves more fossil energy and protects resource while lessens the nature's eutrophication risk. The technical, economic, and environmental assessments confirm MgCl 2 as a promisable source of magnesium in struvite crystallization process for achieving cleaner production goal.
研究领域:
环境科学
·
废水处理
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2022
·
IF 13.4
Xuewei Li,Xu Zhao,Juanjuan Zhang,Jingwei Hao,Qiwu Zhang
Recovery of phosphorus from wastewater through struvite crystallization is one of the most attractive methods. However, the cost of chemical consumption makes this technology is unattractive to some extent. In this work, highly active serpentine was prepared by one-step mechanical activation and then used to recover phosphate as struvite from the black water containing 132.8 mg/L phosphorus and 3144 mg/L ammonia nitrogen. The results indicated that the prepared active serpentine can release magnesium ions and hydroxide ions simultaneously into an aqueous solution and is an ideal raw material for struvite crystallization. The factors for phosphorus recovery in this process mainly include mechanical activation intensity, serpentine dosage, and contact time. For the actual black water, a high recovery rate of phosphorus (>98%) is achieved by using active serpentine as the magnesium and alkali source for struvite precipitation. The recovery product was identified as struvite with a median particle size of 32.96 μm. It was confirmed that the mechanical activation damaged the crystal structure of the raw serpentine, improving the activity of Mg 2+ and OH − . The undissolved Si-containing particles act as crystal seeds, accelerating the struvite crystallization process. Furthermore, a pilot-scale test was conducted with a rural public toilet in Xiong'an New District, Hebei Province. The results showed that an acceptable phosphorus recovery (98%) could be achieved using active serpentine. Additionally, it was demonstrated that the serpentine process to recover phosphate as struvite reduced the cost by 54.4% in compared with an ordinary chemical process. The active serpentine is a promising dual source of magnesium and alkali for the phosphorus recovery by the struvite method. It has a potential prospect for the large-scale application in phosphorus recovery and struvite fertilizer production.
研究领域:
环境科学
·
废水处理
·
资源回收
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials
·
2022
·Vol. 15
·期 22
·8021
·
IF 3.748
Zilong Liang,Zhiji Zhou,Yunqi Sun,Yujia Huang,Xinya Guo,Guoshuai Cai,Mingchao Wang,Haijun Zhang
Struvite is a chemically bonded ceramic product in the pipeline of a sewage treatment plant. In order to explore the fire extinguishing potential of struvite, a new type of struvite ultrafine dry powder with excellent performance was prepared by a simple process, and its fire extinguishing performance and mechanism were analyzed in depth. Under the same process conditions, the refinement degree (D50 = 5.132 μm) and the specific surface area (BET = 25.72 m2/g) of ultrafine struvite were larger than those of NH4H2PO4(D50 = 8.961 μm, BET = 13.64 m2/g), making struvite more suitable for fire extinguishing. Besides, the pyrolysis process of struvite was relatively concentrated and absorbed more heat in a short time. Its heat absorption (458.4 J/mg) was higher than that of NH4H2PO4(156.4 J/mg). Water, ammonia, and PO· were released during the pyrolysis of struvite, which effectively reduced fire temperature, diluted oxygen concentrations and captured free radicals. At the same time, the final products were magnesium orthophosphate and magnesium pyrophosphate, which formed a dense flame-retardant ceramic layer with good thermal insulation and environmental protection functions. In these cases, the fire extinguishing mechanism of struvite was determined to have three stages: the cooling effect, the asphyxiation effect, and the chemical effect. Correspondingly, the fire extinguishing time of struvite was three seconds faster than that of ammonium phosphate under 0.2 MPa based on the local oil basin test.Keywords:chemically bonded ceramic;struvite;recycling;ultrafine powder;fire extinguishing performance
研究领域:
材料科学
·
环境科学
·
消防安全
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Frontiers in Chemistry
·
2022
·
IF 5.545
Wang Saier,Sun Kechun,Xiang Huiming,Zhao Zhiqiang,Shi Ying,Su Lianghu,Tan Chaoqun,Zhang Longjiang
Refuse transfer station (RTS) leachate treatment call for efficient methods to increase nutrient recovery (NH4+−N and PO43−−P) and chemical oxygen demand (COD) removal. In this study, the effects of various operational factors (seeding dose, pH, initial NH4+-N concentration, and reaction time) on biochar-seeded struvite precipitation were investigated at laboratory and pilot scales. Mealworm frass biochar (MFB) and corn stover biochar (CSB) were used as seeding materials to compare with traditional seed struvite. The maximum NH4+−N and PO43−−P recover efficiency of the MFB-seeded process reached 85.4 and 97.5%, higher than non-seeded (78.5 and 88.0%) and CSB-seeded (80.5 and 92.0%) processes and close to the struvite-seeded (84.5 and 95.1%) process. The MFB-seeded process also exhibited higher COD removal capacity (46.4%) compared to CSB-seeded (35.9%) and struvite-seeded (31.2%) processes and increased the average particle size of the struvite product from 33.7 to 70.2 μm for better sustained release. XRD, FT-IR, and SEM confirmed the orthorhombic crystal structure with organic matter attached to the struvite product. A pilot-scale test was further carried out in a custom-designed stirred tank reactor (20 L). In the pilot-scale test, the MFB-seeded process still spectacularly recovered 77.9% of NH4+−N and 96.1% of PO43−−P with 42.1% COD removal, which was slightly lower than the laboratory test due to insufficient and uniform agitation. On the whole, MFB-seeded struvite precipitation is considered to be a promising pretreatment method for rural RTS leachate.
研究领域:
环境科学
·
废水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2025
·
IF 9.7
Changjin Guo,Yinghao Xu,Congcong Ni,Xiaofan Pan,Leonard D. Tijing,Ho Kyong Shon,Ning Deng,Xin Huang
Nitrogen and phosphorus recovery from wastewater to produce struvite fertilizer can simultaneously alleviate water eutrophication and phosphorus scarcity. Coupled magnesium mineral dissolution and reprecipitation has been emphasized for struvite formation by avoiding excessive Mg salts addition and pH adjustment. However, the recovery efficiency is limited by the low solubility of magnesium mineral. Herein, we capitalized on the concept of “pore-size controlled solubility (PCS)” to enhance the dissolution of MgAl-layered double oxide (MgAl-LDO), where dissolution rate is inversely related to pore size. By reducing the pore size of LDO X from 9.2 to 5.5 nm, the magnesium release from LDO X dissolution increased from 64.0 to 99.0 mg/L, accompanied by OH − release to maintain an alkaline condition. This resulted in effective recovery of NH 4 -N (80.54%) and PO 4 -P (80.57%) as high-purity struvite. Scanning electron microscope revealed that LDO acted as seeded surfaces that significantly reduced struvite nucleation barrier by controlling local supersaturation and interfacial energy. Moreover, the recovery is stable across wide pH ranges (5.0–10.0), attributable to the buffering capacity of Al in LDO X . Finally, the feasibility of NH 4 -N and PO 4 -P recovery was successfully applied to real aquaculture wastewater. This study offers an effective strategy to enhance mineral dissolution-precipitation for resource recovery.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）