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  1. Determining the main contributing factors to nutrient concentration in rivers in arid northwest China using partial least squares structural equation modeling
    Wang W, Zhang F, Zhao Q, Liu C, Jim CY, Johnson VC, et al.
    J Environ Manage, 2023 Oct 01;343:118249.
    PMID: 37245314 DOI: 10.1016/j.jenvman.2023.118249
    Understanding the main driving factors of oasis river nutrients in arid areas is important to identify the sources of water pollution and protect water resources. Twenty-seven sub-watersheds were selected in the lower oasis irrigated agricultural reaches of the Kaidu River watershed in arid Northwest China, divided into the site, riparian, and catchment buffer zones. Data on four sets of explanatory variables (topographic, soil, meteorological elements, and land use types) were collected. The relationships between explanatory variables and response variables (total phosphorus, TP and total nitrogen, TN) were analyzed by redundancy analysis (RDA). Partial least squares structural equation modeling (PLS-SEM) was used to quantify the relationship between explanatory as well as response variables and fit the path relationship among factors. The results showed that there were significant differences in the TP and TN concentrations at each sampling point. The catchment buffer exhibited the best explanatory power of the relationship between explanatory and response variables based on PLS-SEM. The effects of various land use types, meteorological elements (ME), soil, and topography in the catchment buffer were responsible for 54.3% of TP changes and for 68.5% of TN changes. Land use types, ME and soil were the main factors driving TP and TN changes, accounting for 95.56% and 94.84% of the total effects, respectively. The study provides a reference for river nutrients management in arid oases with irrigated agriculture and a scientific and targeted basis to mitigate water pollution and eutrophication of rivers in arid lands.
    Matched MeSH terms: Phosphorus/analysis
  2. Vegetation restoration effects on soil carbon and nutrient concentrations and enzymatic activities in post-mining lands are mediated by mine type, climate, and former soil properties
    Yuan C, Wu F, Wu Q, Fornara DA, Heděnec P, Peng Y, et al.
    Sci Total Environ, 2023 Jun 25;879:163059.
    PMID: 36963687 DOI: 10.1016/j.scitotenv.2023.163059
    Vegetation restoration is a widely used, effective, and sustainable method to improve soil quality in post-mining lands. Here we aimed to assess global patterns and driving factors of potential vegetation restoration effects on soil carbon, nutrients, and enzymatic activities. We synthesized 4838 paired observations extracted from 175 publications to evaluate the effects that vegetation restoration might have on the concentrations of soil carbon, nitrogen, and phosphorus, as well as enzymatic activities. We found that (1) vegetation restoration had consistent positive effects on the concentrations of soil organic carbon, total nitrogen, available nitrogen, ammonia, nitrate, total phosphorus, and available phosphorus on average by 85.4, 70.3, 75.7, 54.6, 58.6, 34.7, and 60.4 %, respectively. Restoration also increased the activities of catalase, alkaline phosphatase, sucrase, and urease by 63.3, 104.8, 125.5, and 124.6 %, respectively; (2) restoration effects did not vary among different vegetation types (i.e., grass, tree, shrub and their combinations) or leaf type (broadleaved, coniferous, and mixed), but were affected by mine type; and (3) latitude, climate, vegetation species richness, restoration year, and initial soil properties are important moderator variables, but their effects varied among different soil variables. Our global scale study shows how vegetation restoration can improve soil quality in post-mining lands by increasing soil carbon, nutrients, and enzymatic activities. This information is crucial to better understand the role of vegetation cover in promoting the ecological restoration of degraded mining lands.
    Matched MeSH terms: Phosphorus/analysis
  3. Potential of bioretention plants in treating urban runoff polluted with greywater under tropical climate
    Jhonson P, Goh HW, Chan DJC, Juiani SF, Zakaria NA
    Environ Sci Pollut Res Int, 2023 Feb;30(9):24562-24574.
    PMID: 36336739 DOI: 10.1007/s11356-022-23605-5
    Bioretention systems are among the most popular stormwater best management practices (BMPs) for urban runoff treatment. Studies on plant performance using bioretention systems have been conducted, especially in developed countries with a temperate climate, such as the USA and Australia. However, these results might not be applicable in developing countries with tropical climates due to the different rainfall regimes and the strength of runoff pollutants. Thus, this study focuses on the performance of tropical plants in treating urban runoff polluted with greywater using a bioretention system. Ten different tropical plant species were triplicated and planted in 30 mesocosms with two control mesocosms without vegetation. One-way ANOVA was used to analyze the performance of plants, which were then ranked based on their performance in removing pollutants using the total score obtained for each water quality test. Results showed that vetiver topped the table with 86.4% of total nitrogen (TN) removal, 93.5% of total phosphorus (TP) removal, 89.8% of biological oxygen demand (BOD) removal, 90% of total suspended solids (TSS) removal, and 92.5% of chemical oxygen demand (COD) removal followed by blue porterweed, Hibiscus, golden trumpet, and tall sedge which can be recommended to be employed in future bioretention studies.
    Matched MeSH terms: Phosphorus/analysis
  4. Analysis on the changes of fertilization intensity and efficiency in China's grain production from 1980 to 2019
    Liu Q, Wu TY, Tu W, Pu L
    J Sci Food Agric, 2023 Jan 30;103(2):908-916.
    PMID: 36067269 DOI: 10.1002/jsfa.12202
    BACKGROUND: Relieving serious non-point source pollution of nitrogen (N), phosphorus (P), and potassium (K) is an urgent task in China. It is necessary to explore the changing characteristics of chemical fertilization intensity (FI) and efficiency to provide references. A new method of 'relative productivity proportion weight', which was simpler than data envelope analysis, was proposed to construct models of fertilizer allocation efficiency (FAE) and chemical fertilizer integrated efficiency (FIE) by considering NPK multi-inputs and the grain output scale, respectively.

    RESULTS: During 1980-2014, the FIs of NPK chemical fertilizers in China showed a significant growing trend. After reaching the highest value of 339 kg ha-1 in 2014, FIs were reduced to 303 kg ha-1 in 2019, higher than the 225 kg ha-1 maximum safe usage internationally recognized. Meanwhile, the pattern of change of FAE was one of 'decreasing to increasing', with values of 1 in 1980, 0.66 in 2003, and 0.80 in 2019. FIE basically showed an increasing trend, which could be divided into three stages: the first stage of low efficiency during 1980-2009, the second stage of medium efficiency after 2010, and the third stage of high efficiency after 2018.

    CONCLUSION: From 1980 until 2019, a reduction of FAE from 1 to 0.80 with an average of 0.75 was observed in China. FIE was found between 0.65 and 0.85 and had the potential of upgrading by 15-35%. Therefore, China needs to improve the fertilizer use efficiency in order to strive for negative growth of chemical fertilizer intensity and ecological agriculture construction. © 2022 Society of Chemical Industry.

    Matched MeSH terms: Phosphorus/analysis
  5. Macro-nutrients recovery from liquid waste as a sustainable resource for production of recovered mineral fertilizer: Uncovering alternative options to sustain global food security cost-effectively
    Sniatala B, Kurniawan TA, Sobotka D, Makinia J, Othman MHD
    Sci Total Environ, 2023 Jan 15;856(Pt 2):159283.
    PMID: 36208738 DOI: 10.1016/j.scitotenv.2022.159283
    Global food security, which has emerged as one of the sustainability challenges, impacts every country. As food cannot be generated without involving nutrients, research has intensified recently to recover unused nutrients from waste streams. As a finite resource, phosphorus (P) is largely wasted. This work critically reviews the technical applicability of various water technologies to recover macro-nutrients such as P, N, and K from wastewater. Struvite precipitation, adsorption, ion exchange, and membrane filtration are applied for nutrient recovery. Technological strengths and drawbacks in their applications are evaluated and compared. Their operational conditions such as pH, dose required, initial nutrient concentration, and treatment performance are presented. Cost-effectiveness of the technologies for P or N recovery is also elaborated. It is evident from a literature survey of 310 published studies (1985-2022) that no single technique can effectively and universally recover target macro-nutrients from liquid waste. Struvite precipitation is commonly used to recover over 95 % of P from sludge digestate with its concentration ranging from 200 to 4000 mg/L. The recovered precipitate can be reused as a fertilizer due to its high content of P and N. Phosphate removal of higher than 80 % can be achieved by struvite precipitation when the molar ratio of Mg2+/PO43- ranges between 1.1 and 1.3. The applications of artificial intelligence (AI) to collect data on critical parameters control optimization, improve treatment effectiveness, and facilitate water utilities to upscale water treatment plants. Such infrastructure in the plants could enable the recovered materials to be reused to sustain food security. As nutrient recovery is crucial in wastewater treatment, water treatment plant operators need to consider (1) the costs of nutrient recovery techniques; (2) their applicability; (3) their benefits and implications. It is essential to note that the treatment cost of P and/or N-laden wastewater depends on the process applied and local conditions.
    Matched MeSH terms: Phosphorus/analysis
  6. Fulltext Dominant phytoplankton groups as the major source of polyunsaturated fatty acids for hilsa (Tenualosa ilisha) in the Meghna estuary Bangladesh
    Shaha DC, Hasan J, Kundu SR, Yusoff FM, Salam MA, Khan M, et al.
    Sci Rep, 2022 Dec 05;12(1):20980.
    PMID: 36470973 DOI: 10.1038/s41598-022-24500-2
    The tropical estuarine ecosystem is fascinating for studying the dynamics of water quality and phytoplankton diversity due to its frequently changing hydrological conditions. Most importantly, phytoplankton is the main supplier of ω3 polyunsaturated fatty acids (PUFA) in the coastal food web for fish as they could not synthesize PUFA. This study evaluated seasonal variations of water quality parameters in the Meghna River estuary (MRE), explored how phytoplankton diversity changes according to hydro-chemical parameters, and identified the major phytoplankton groups as the main source of PUFA for hilsa fish. Ten water quality indicators including temperature, dissolved oxygen, pH, salinity, dissolved inorganic nitrogen (DIN = nitrate, nitrite, ammonia) and phosphorus, dissolved silica and chlorophyll-a were evaluated. In addition, phytoplankton diversity was assessed in the water and hilsa fish gut. Principal component analysis (PCA) was used to analyze the spatio-temporal changes in the water quality conditions, and the driving factors in the MRE. Four main components were extracted and explained 75.4% variability of water quality parameters. The most relevant driving factors were dissolved oxygen, salinity, temperature, and DIN (nitrate, nitrite and ammonia). These variabilities in physicochemical parameters and dissolved inorganic nutrients caused seasonal variations in two major groups of phytoplankton. Peak abundance of Chlorophyta (green algae) occurred in water in nutrient-rich environments (nitrogen and phosphorus) during the wet (36%) season, while Bacillariophyta (diatoms) were dominant during the dry (32%) season that depleted dissolved silica. Thus, the decrease of green algae and the increase of diatoms in the dry season indicated the potential link to seasonal changes of hydro-chemical parameters. The green algae (53.7%) were the dominant phytoplankton group in the hilsa gut content followed by diatoms (22.6%) and both are contributing as the major source of PUFAs for hilsa fish according to the electivity index as they contain the highest amounts of PUFAs (60 and 28% respectively).
    Matched MeSH terms: Phosphorus/analysis
  7. The spatial distribution of physicochemical parameters in coastal sediments along the Bay of Bengal Coastal Zone with statistical analysis
    Pandion K, Arunachalam KD, Dowlath MJH, Chinnapan S, Chang SW, Chang W, et al.
    Environ Monit Assess, 2022 Nov 19;195(1):126.
    PMID: 36401680 DOI: 10.1007/s10661-022-10568-w
    The current study focused on the monitoring of pollution loads in the Kalpakkam coastal zone of India in terms of physico-chemical characteristics of sediment. The investigation took place at 12 sampling points around the Kalpakkam coastal zone for one year beginning from 2019. The seasonal change of nutrients in the sediment, such as nitrogen, phosphorus, potassium, total organic carbon, and particles size distribution, was calculated. Throughout the study period, the pH (7.55 to 8.99), EC (0.99 to 4.98 dS/m), nitrogen (21.74 to 58.12 kg/ha), phosphorus (7.5 to 12.9 kg/ha), potassium (218 to 399 kg/ha), total organic carbon (0.11 to 0.88%), and particle size cumulative percent of sediments (from 9.01 to 9.39%) was observed. A number of multivariate statistical techniques were used to examine the changes in sediment quality. The population means were substantially different according to the three-way ANOVA test at the 0.05 level. Principal component analysis and cluster analysis showed a substantial association with all indicators throughout all seasons, implying contamination from both natural and anthropogenic causes. The ecosystem of the Kalpakkam coastal zone has been affected by nutrient contamination.
    Matched MeSH terms: Phosphorus/analysis
  8. Fulltext Phosphorus Removal and Phytonutrients Retention in the Refining of Solvent Extracted Palm-Pressed Mesocarp Fiber Oil
    Lau HLN, Tee YS, Chan MK, Teh SS
    J Oleo Sci, 2022;71(2):177-185.
    PMID: 35110462 DOI: 10.5650/jos.ess21256
    Phosphoric acid is used in the refining of palm oil for the removal of phosphatides. The high concentration of phosphorus in solvent extracted palm-pressed mesocarp fiber oil hinders palm oil mills to recover this phytonutrients-rich residual oil in pressed fiber which typically contains 0.1 to 0.2% of total oil yield. This study aimed to refine the palm-pressed mesocarp fiber oil and determine the optimum dosage of phosphoric acid for acid-degumming of palm-pressed mesocarp fiber oil while retaining its phytonutrients. The refining process was carried out with combination of wet degumming, acid degumming, neutralisation, bleaching and deodorization. The optimum dose of phosphoric acid was identified as 0.05 wt.% by incorporating the wet degumming process. The refined palm-pressed mesocarp fiber oil showed a reduction in phosphorus content by 97% (from 901 ppm to 20 ppm) and 97% free fatty acid content removal (from 6.36% to 0.17%), while the Deterioration of Bleachability Index increased from 1.76 to 2.48, which showed an increment of 41%. The refined oil retained the key phytonutrients such as carotenoids (1,150 ppm) and vitamin E (1,540 ppm) that can be further developed into high-value products. The oil meets the quality specification of refined, bleached, and deodorized palm oil while preserving the heat-sensitive phytonutrients, which in turn provides a new resource of nutritious oil.
    Matched MeSH terms: Phosphorus/analysis
  9. Blooms of diatom and dinoflagellate associated with nutrient imbalance driven by cycling of nitrogen and phosphorus in anaerobic sediments in Johor Strait (Malaysia)
    Chai X, Li X, Hii KS, Zhang Q, Deng Q, Wan L, et al.
    Mar Environ Res, 2021 Jul;169:105398.
    PMID: 34171592 DOI: 10.1016/j.marenvres.2021.105398
    Coastal eutrophication is one of the pivotal factors driving occurrence of harmful algal blooms (HABs), whose underlying mechanism remained unclear. To better understand the nutrient regime triggering HABs and their formation process, the phytoplankton composition and its response to varying nitrogen (N) and phosphorus (P), physio-chemical parameters in water and sediment in Johor Strait in March 2019 were analyzed. Surface and sub-surface HABs were observed with the main causative species of Skeletonema, Chaetoceros and Karlodinium. The ecophysiological responses of Skeletonema to the low ambient N/P ratio such as secreting alkaline phosphatase, regulating cell morphology (volume; surface area/volume ratio) might play an important role in dominating the community. Anaerobic sediment iron-bound P release and simultaneous N removal by denitrification and anammox, shaped the stoichiometry of N and P in water column. The decrease of N/P ratio might shift the phytoplankton community into the dominance of HABs causative diatoms and dinoflagellates.
    Matched MeSH terms: Phosphorus/analysis
  10. Fulltext Plant growth promoting rhizobacteria improve growth and yield related attributes of chili under low nitrogen availability
    Raza A, Ejaz S, Saleem MS, Hejnak V, Ahmad F, Ahmed MAA, et al.
    PLoS One, 2021;16(12):e0261468.
    PMID: 34919599 DOI: 10.1371/journal.pone.0261468
    Nitrogen (N) is a macronutrient desired by crop plants in large quantities. However, hiking fertilizer prices need alternative N sources for reducing its requirements through appropriate management practices. Plant growth promoting rhizobacteria (PGPR) are well-known for their role in lowering N requirements of crop plants. This study assessed the impact of PGPR inoculation on growth, allometry and biochemical traits of chili under different N doses. Two PGPR, i.e., Azospirillum 'Er-20' (nitrogen fixing) and Agrobacterium 'Ca-18' (phosphorous solubilizing) were used for inoculation, while control treatment had no PGPR inoculation. Six N doses, i.e., 100, 80, 75, 70, 60 and 50% of the N required by chili were included in the study. Data relating to growth traits, biochemical attributes and yield related traits were recorded. Interaction among N doses and PGPR inoculation significantly altered all growth traits, biochemical attributes and yield related traits. The highest values of the recorded traits were observed for 100% N with and without PGPR inoculation and 75% N with PGPR inoculation. The lowest values of the recorded traits were noted for 50% N without PGPR inoculation. The PGPR inoculation improved the measured traits compared to the traits recorded noted in same N dose without PGPR inoculation. Results revealed that PGPR had the potential to lower 25% N requirement for chili. Therefore, it is recommended that PGPR must be used in chili cultivation to lower N requirements.
    Matched MeSH terms: Phosphorus/analysis
  11. Effects of Soil Amendments on Microbial Activities in a Typical Cd-Contaminated Purple Field Soil, Southwestern China
    Wang W, Zhou F, Chang Y, Cui J, He D, Du J, et al.
    Bull Environ Contam Toxicol, 2020 Mar;104(3):380-385.
    PMID: 31932904 DOI: 10.1007/s00128-020-02786-0
    In this study, three soil amendments (inorganic, liming, or organic-inorganic materials) were used in a Cd-contaminated purple field soil to investigate their impacts on soil Cd availability, enzyme (urease, catalase, sucrase, and acid phosphatase) activities, microbial biomass (carbon/nitrogen) and type (bacteria, fungi, and actinomycetes) in mustard and corn trials. Results showed that soil amendments generally decreased soil exchangeable Cd, fungi and bacterial populations while increasing the activities of all the four soil enzymes tested, microbial biomass carbon and populations of actinomycetes (p  0.05) whereas stronger effects appeared in soil organic matter and available nutrients (nitrogen, phosphorous and potassium; p 
    Matched MeSH terms: Phosphorus/analysis
  12. A review of bioretention components and nutrient removal under different climates-future directions for tropics
    Goh HW, Lem KS, Azizan NA, Chang CK, Talei A, Leow CS, et al.
    Environ Sci Pollut Res Int, 2019 May;26(15):14904-14919.
    PMID: 30977005 DOI: 10.1007/s11356-019-05041-0
    Bioretention systems have been implemented as stormwater best management practices (BMPs) worldwide to treat non-point sources pollution. Due to insufficient research, the design guidelines for bioretention systems in tropical countries are modeled after those of temperate countries. However, climatic factors and stormwater runoff characteristics are the two key factors affecting the capacity of bioretention system. This paper reviews and compares the stormwater runoff characteristics, bioretention components, pollutant removal requirements, and applications of bioretention systems in temperate and tropical countries. Suggestions are given for bioretention components in the tropics, including elimination of mulch layer and submerged zone. More research is required to identify suitable additives for filter media, study tropical shrubs application while avoiding using grass and sedges, explore function of soil faunas, and adopt final discharged pollutants concentration (mg/L) on top of percentage removal (%) in bioretention design guidelines.
    Matched MeSH terms: Phosphorus/analysis
  13. Nutrient availability in the Setiu Wetland Lagoon, Malaysia: trends, possible causes and environmental impacts
    Poh SC, Ng NCW, Suratman S, Mathew D, Mohd Tahir N
    Environ Monit Assess, 2018 Dec 04;191(1):3.
    PMID: 30515582 DOI: 10.1007/s10661-018-7128-y
    The objective of this study was to identify the spatial and temporal variabilities of selected nutrients in the Setiu Wetlands Lagoon (SWL), Malaysia. Water samples were collected quarterly at ten monitoring sites. This study presents results from a 10-year field investigation (2003 to 2010 and 2014 to 2015) of water quality in the SWL. For the spatial pattern, four clusters were identified with hierarchical cluster analysis. Analysis of the temporal trend shows that the high total suspended solid loading in 2010 was due to large-scale land clearing upstream of the SWL. The enrichment of ammonium after 2010 could plausibly be due to land-based aquaculture diffuse discharges. In 2005-2007, expansion of oil palm plantations within the Setiu catchment had doubled the phosphorus concentration in the SWL. The natural and anthropogenic alterations of the lagoon inlets profoundly influenced the spatial distribution patterns of nutrients in the SWL. These results suggest that intense anthropogenic disturbances close to the SWL accounted for the water quality deterioration.
    Matched MeSH terms: Phosphorus/analysis
  14. Responses of phytoplankton community to eutrophication in Semerak Lagoon (Malaysia)
    Er HH, Lee LK, Lim ZF, Teng ST, Leaw CP, Lim PT
    Environ Sci Pollut Res Int, 2018 Aug;25(23):22944-22962.
    PMID: 29858995 DOI: 10.1007/s11356-018-2389-0
    Effects of aquaculture activities on the environmental parameters and phytoplankton community structure were investigated in a semi-enclosed lagoon located at Semerak River, Malaysia. Elevated concentrations of phosphate and ammonia were observed at the aquaculture area and the inner lagoon. Relatively low dissolved oxygen, high total chlorophyll a, and high phytoplankton abundances but low species richness were recorded. Chaetoceros, Pseudo-nitzschia brasiliana, Blixaea quinquecornis, and Skeletonema blooms were observed, and some were associated with anoxia condition. Eutrophication level assessed by UNTRIX suggests that the water quality in the lagoon is deteriorating. Dissolved inorganic phosphorus and nitrogen at the impacted area were 15 and 12 times higher than the reference sites, respectively. Such trophic status indices could provide a useful guideline for optimal aquaculture management plan to reduce the environmental impact caused by aquaculture.
    Matched MeSH terms: Phosphorus/analysis
  15. Distributions of particulate and dissolved phosphorus in aquatic habitats of Peninsular Malaysia
    Lim JH, Lee CW, Bong CW, Affendi YA, Hii YS, Kudo I
    Mar Pollut Bull, 2018 Mar;128:415-427.
    PMID: 29571392 DOI: 10.1016/j.marpolbul.2018.01.037
    Particulate phosphorus was the dominant phosphorus species and accounted for 72 ± 5% of total phosphorus in coastal habitats, 63 ± 4% in estuaries, 58 ± 6% in lakes and 80 ± 7% in aquaculture farms whereas dissolved inorganic phosphorus (DIP) and dissolved organic phosphorus (DOP) were minor components. Correlation analyses (DIP vs Chl a; R2 = 0.407, df = 31, p 
    Matched MeSH terms: Phosphorus/analysis*
  16. River sediment metal and nutrient variations along an urban-agriculture gradient in an arid austral landscape: implications for environmental health
    Dalu T, Wasserman RJ, Wu Q, Froneman WP, Weyl OLF
    Environ Sci Pollut Res Int, 2018 Jan;25(3):2842-2852.
    PMID: 29143261 DOI: 10.1007/s11356-017-0728-1
    The effect of metals on environmental health is well documented and monitoring these and other pollutants is considered an important part of environmental management. Developing countries are yet to fully appreciate the direct impacts of pollution on aquatic ecosystems and as such, information on pollution dynamics is scant. Here, we assessed the temporal and spatial dynamics of stream sediment metal and nutrient concentrations using contaminant indices (e.g. enrichment factors, pollution load and toxic risk indices) in an arid temperate environment over the wet and dry seasons. The mean sediment nutrient, organic matter and metal concentration were highest during the dry season, with high values being observed for the urban environment. Sediment contaminant assessment scores indicated that during the wet season, the sediment quality was acceptable, but not so during the dry season. The dry season had low to moderate levels of enrichment for metals B, Cu, Cr, Fe, Mg, K and Zn. Overall, applying the sediment pollution load index highlighted poor quality river sediment along the length of the river. Toxic risk index indicated that most sites posed no toxic risk. The results of this study highlighted that river discharge plays a major role in structuring temporal differences in sediment quality. It was also evident that infrastructure degradation was likely contributing to the observed state of the river quality. The study contributes to our understanding of pollution dynamics in arid temperate landscapes where vast temporal differences in base flow characterise the riverscape. Such information is further useful for contrasting sediment pollution dynamics in aquatic environments with other climatic regions.
    Matched MeSH terms: Phosphorus/analysis
  17. Fulltext Effects of clinoptilolite zeolite on phosphorus dynamics and yield of Zea Mays L. cultivated on an acid soil
    Nur Aainaa H, Haruna Ahmed O, Ab Majid NM
    PLoS One, 2018;13(9):e0204401.
    PMID: 30261005 DOI: 10.1371/journal.pone.0204401
    Efficient management of P fertilizers ensures good yield of crops and adequate food supply. In the acid soil of the tropics, soluble P is fixed by Al and Fe. Exploitation of the high CEC and pH of Clinoptilolite zeolite (CZ) could mitigate low soil pH and P fixation in acid soils. This study was undertaken to determine the effects of amending a weathered acid soil with CZ on: (i) soil P availability and other related soil chemical properties, and (ii) nutrient concentration, nutrient uptake, above-ground biomass, agronomic efficiency, and yield of Zea mays L. on a tropical acidic soil. Triple superphosphate (TSP), Egypt Rock phosphate (ERP), and Christmas Island Rock phosphate (CIRP) were used as P sources. The treatments evaluated were: (i) soil alone, (ii) 100% recommended fertilizer rate (NPK), and (iii) 75% fertilizer rate + Clinoptilolite zeolite. Selected soil chemical properties and P availability were determined before and after field trials. Zea mays L. above-ground biomass, nutrient concentration, nutrient uptake, agronomic efficiency, and fresh cob yield were also determined. Results revealed that the effects of treatments with and without CZ treatments on soil pH, P fractions, soil acidity, dry matter production, yield of maize, nutrient uptake, and agronomic efficiency were similar. Hence, suggesting CZ inclusion in the fertilization program of Zea mays L is beneficial in terms of reducing excessive or unbalanced use of chemical fertilizers due to reduction of fertilizers usage by 25%.
    Matched MeSH terms: Phosphorus/analysis
  18. Nutrient fluxes across sediment-water interface in Bohai Bay Coastal Zone, China
    Mu D, Yuan D, Feng H, Xing F, Teo FY, Li S
    Mar Pollut Bull, 2017 Jan 30;114(2):705-714.
    PMID: 27802871 DOI: 10.1016/j.marpolbul.2016.10.056
    Sediment cores and overlying water samples were collected at four sites in Tianjin Coastal Zone, Bohai Bay, to investigate nutrient (N, P and Si) exchanges across the sediment-water interface. The exchange fluxes of each nutrient species were estimated based on the porewater profiles and laboratory incubation experiments. The results showed significant differences between the two methods, which implied that molecular diffusion alone was not the dominant process controlling nutrient exchanges at these sites. The impacts of redox conditions and bioturbation on the nutrient fluxes were confirmed by the laboratory incubation experiments. The results from this study showed that the nutrient fluxes measured directly from the incubation experiment were more reliable than that predicted from the porewater profiles. The possible impacts causing variations in the nutrient fluxes include sewage discharge and land reclamation.
    Matched MeSH terms: Phosphorus/analysis
  19. Fulltext Salinity-induced changes in the morphology and major mineral nutrient composition of purslane (Portulaca oleracea L.) accessions
    Alam MA, Juraimi AS, Rafii MY, Hamid AA, Aslani F, Hakim MA
    Biol Res, 2016 Apr 18;49:24.
    PMID: 27090643 DOI: 10.1186/s40659-016-0084-5
    This study was undertaken to determine the effects of varied salinity regimes on the morphological traits (plant height, number of leaves, number of flowers, fresh and dry weight) and major mineral composition of 13 selected purslane accessions. Most of the morphological traits measured were reduced at varied salinity levels (0.0, 8, 16, 24 and 32 dS m(-1)), but plant height was found to increase in Ac1 at 16 dS m(-1) salinity, and Ac13 was the most affected accession. The highest reductions in the number of leaves and number of flowers were recorded in Ac13 at 32 dS m(-1) salinity compared to the control. The highest fresh and dry weight reductions were noted in Ac8 and Ac6, respectively, at 32 dS m(-1) salinity, whereas the highest increase in both fresh and dry weight was recorded in Ac9 at 24 dS m(-1) salinity compared to the control. In contrast, at lower salinity levels, all of the measured mineral levels were found to increase and later decrease with increasing salinity, but the performance of different accessions was different depending on the salinity level. A dendrogram was also constructed by UPGMA based on the morphological traits and mineral compositions, in which the 13 accessions were grouped into 5 clusters, indicating greater diversity among them. A three-dimensional principal component analysis also confirmed the output of grouping from cluster analysis.
    Matched MeSH terms: Phosphorus/analysis
  20. Comparison of the efficiencies of attached- versus suspended-growth SBR systems in the treatment of recycled paper mill wastewater
    Muhamad MH, Sheikh Abdullah SR, Abu Hasan H, Abd Rahim RA
    J Environ Manage, 2015 Nov 1;163:115-24.
    PMID: 26311084 DOI: 10.1016/j.jenvman.2015.08.012
    The complexity of residual toxic organics from biologically treated effluents of pulp and paper mills is a serious concern. To date, it has been difficult to choose the best treatment technique because each of the available options has advantages and drawbacks. In this study, two different treatment techniques using laboratory-scale aerobic sequencing batch reactors (SBRs) were tested with the same real recycled paper mill effluent to evaluate their treatment efficiencies. Two attached-growth SBRs using granular activated carbon (GAC) with and without additional biomass and a suspended-growth SBR were used in the treatment of real recycled paper mill effluent at a chemical oxygen demand (COD) level in the range of 800-1300 mg/L, a fixed hydraulic retention time of 24 h and a COD:N:P ratio of approximately 100:5:1. The efficiency of this biological treatment process was studied over a 300-day period. The six most important wastewater quality parameters, namely, chemical oxygen demand (COD), turbidity, ammonia (expressed as NH3-N), phosphorus (expressed as PO4(3)-P), colour, and suspended solids (SS), were measured to compare the different treatment techniques. It was determined that these processes were able to almost completely and simultaneously eliminate COD (99%) and turbidity (99%); the removals of NH3-N (90-100%), PO4(3)-P (66-78%), colour (63-91%), and SS (97-99%) were also sufficient. The overall performance results confirmed that an attached-growth SBR system using additional biomass on GAC is a promising configuration for wastewater treatment in terms of performance efficiency and process stability under fluctuations of organic load. Hence, this hybrid system is recommended for the treatment of pulp and paper mill effluents.
    Matched MeSH terms: Phosphorus/analysis
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