Benthic dinoflagellates are known to occur in the water column. The reason they can be found in different parts of the ecosystem is not clear. This study aims to determine the species and the cell abundance of benthic dinoflagellates in the water column and macrophytes collected from two different locations i.e. semi-enclosed lagoon and open coastal waters. The physico-chemical parameters (temperature, salinity, pH, dissolved oxygen) and nutrients (nitrate and phosphate) were determined. Results showed that in the lagoon, the most abundant dinoflagellate species on the macrophytes was also the most abundant dinoflagellate species in the water column. The species that dominated the water column and marophytes in the lagoon was Bysmatrum caponii. In the coastal area the trend was not clear. Coolia dominated the macrophytes whereas Peridinium quinquecorne dominated the water column. The physico-chemical parameters determined were similar at both sites except for nutrients. Results show that type of substrates and different geomorphology effects benthic dinoflagellates cell abundance in the macrophytes and water column.
Spillage of water polluting substances via industrial disaster may cause pollution to our environment. Thus, reversed-flow gas chromatography (RF-GC) technique, which applies flow perturbation gas chromatography, was used to investigate the evaporation and estimate the diffusion coefficients of liquid pollutants. Selected alcohols (99.9% purity) and its mixtures were used as samples. The evaporating liquids (stationary phase) were carried out by carrier gas-nitrogen, 99.9% purity (mobile phase) to the detector. The findings of this work showed the physicochemical measurements may vary depending on the composition of water and alcohol mixtures, temperature of the mixtures, as well as the types of alcohol used. This study implies that there is a variation in the results based on the concentration, types and temperature of the liquids that may contribute in the references for future research in the area of environmental pollution analysis.
The adsorption of CO at polycrystalline copper surface was investigated spectroscopically. It was found that CO adsorbed as a linear adsorbed CO, Cu-COL and was a dominant species on copper surface at low CO concentration. A Cu-COL was electrochemically converted to a bridge bonded CO, Cu-COB at a high CO concentration condition. Increasing the CO surface coverage, qCO will increase the formation of adsorbed bridge bonded CO. A nitrogen gas purging treatment was used to examine the stability of an adsorbed CO through the evacuation process. The result showed that Cu-COB remained intact while Cu-COL was completely removed from the copper surface. It suggests that Cu-COL may involve in a weak bonding to a copper surface such as in a physisorbed interaction, while Cu-COB consists much stronger bonding such as a chemisorbed interaction. The N2 purging treatment also gave an additional prove that Cu-COB was partly converted to Cu(I)-CO at anodic potential regions.
The study monitored the characteristics of the leachate collected from ten different landfills and presented the experimental work for the treatment of leachate by immobilized Trametes menziesii. Variation in biological oxygen demand (BOD), chemical oxygen demand (COD) and ammoniacal nitrogen (NH3-N) showed that the age of the leachate has a significant effect on its characteristics and composition. The BOD5/COD ratio tends to decrease as the age of leachate increases, varying from 0.71 for a relatively 'fresh' leachate to 0.62 for an older (more stabilized) one. Variations in the characteristics of the leachate suggested that these leachates are difficult to treat. The principal pollutants in the leachate samples were organic and ammonia loads. Treatment of leachate using immobilized Trametes menziesii achieved 89.14 and 2.11% removals for leachate BOD5 and COD, respectively. These findings suggested that using immobilized Trametes menziesii can remove promising percentage of BOD and COD leachate.
Kajian yang dijalankan ini bertujuan untuk menilai indeks kualiti air di sekitar kawasan lombong di Sungai Pelepah Kanan, Kota Tinggi, Johor. Sebanyak enam stesen pensampelan telah dipilih dari bahagian hulu ke hilir sungai ini untuk menilai indeks kualiti air di sepanjang sungai tersebut. Tiga replikasi sampel telah diambil daripada setiap stesen pensampelan. Pengambilan sampel dilakukan pada dua musim yang berbeza iaitu musim kering (Julai) dan musim hujan (Disember) 2007. Parameter in-situ yang ditentukan dalam kajian ini ialah suhu, pH, oksigen terlarut (DO) dan konduktiviti. Parameter ex-situ yang dianalisis dalam makmal ialah turbiditi air, jumlah pepejal terampai (TSS), keperluan oksigen biokimia (BOD), keperluan oksigen kimia (COD) dan ammonia nitrogen (NH3-N). Berdasarkan Piawaian Interim Kualiti Air Kebangsaan Malaysia (INWQS) hasil kajian yang diperolehi menunjukkan semua stesen pensampelan di Sungai Pelepah Kanan pada bulan Julai berada dalam kelas I kecuali oksigen terlarut dan pH berada dalam kelas II. Selain itu, hasil kajian pada bulan Disember juga menunjukkan semua parameter fiziko-kimia berada dalam kelas I-II kecuali pH berada dalam kelas III. Ujian korelasi menunjukkan terdapat hubungan bererti antara parameter-parameter fiziko-kimia yang di tertentukan. Analisis Indeks Kualiti Air (IKA) menunjukkan nilai purata IKA pada bulan Julai adalah 96.88 (kelas I) manakala pada bulan Disember telah merosot ke 84.03 (kelas II). Berdasarkan kepada nilai IKA dan perbandingan dengan INWQS, indeks kualiti air Sungai Pelepah Kanan adalah berada pada tahap yang bersih dan kurang mengalami pencemaran yang serius daripada aktiviti antropogenik mahupun pencemaran secara semula jadi.
An investigation on a batch production of palm kernel oil polyol (PKO-p) was conducted via esterification and condensation.
The process design was thoroughly studied as a preliminary step for future upscaling. The process variables included
necessity of vacuum pump, controlling of heating rate, recording the production time, nitrogen gas flow and agitator
speed. About 250 mL PKO-p was successfully synthesized within 3 h. Vacuum pressure was applied to haul out moisture
from the system. The control of heating rate and production time are vital to avoid sudden oxidation.
As methyltheobromine (MTB) has been increasingly detected in wastewater, it would be necessary to develop more intensive and effective approaches to remove MTB. As Co species immobilized on carbonaceous materials appears as a promising catalyst, doping carbon with nitrogen has been also validated to significantly enhance catalytic activities for Oxone activation. Therefore, it is desired to develop a composite of immobilizing Co species on N-doped carbonaceous supports for activating Oxone to degrade MTB. Unfortunately, very few studies have demonstrated such composites for activating Oxone to degrade MTB as this type of composites are conventionally prepared via complex procedures. Alternatively, this study aims to develop such a composite conveniently by using a cobaltic coordination polymer (CP) as a precursor. Specifically Co2+ and 4,4-bipyridine (BIPY) are selected for formulating a special one-dimensional CP, which is then carbonized to convert Co to Co nanoparticles (NPs) and transform BIPY to carbon nitride (CN) matrices. Because of 1-D coordinated structure of CoBIPY, the resulting magnetic Co NPs are well-distributed and protected within CN to form a magnetic Co-embedded carbon nitride composite (MCoCN). In comparison to pristine CN and Co3O4, MCoCN exhibits much higher catalytic activities to activate Oxone for degrading MTB completely within 7 min. MCoCN also shows a much lower activation energy of 24.6 kJ/mol than other reported catalysts for activating Oxone to degrade MTB. The findings of this study validate that the 1-D coordination polymer of CoBIPY is a useful precursor to prepare MCoCN for effectively activating Oxone to degrade MTB.
The data collection was initiated to evaluate the effects of supplementary phospholipid to non-fishmeal based diet in order to make functional diets for the Malaysian Mahseer, Tor tambroides. Four iso-nitrogenous and iso-lipidic diets were formulated to consist 100% fishmeal (FM100), 0% fishmeal or full fishmeal replacement (FM0), and 0% fishmeal supplemented with 4% phospholipids (FM0+4%PL), 6% phospholipids (FM0+6%PL). A 60-day feeding trial was conducted and data collection was carried out for the following parameters; growth indices, somatic parameters, whole body nutrient composition, muscle fatty acid composition, haematocrit value and serum lysozyme activity. Fish fed FM0 diets showed significantly poor performance (P
Biochar has proven to be a feasible additive for mitigating nitrogen loss during the composting process. This study aims to evaluate the influence of biochar addition on bacterial community and physicochemical properties changes, including ammonium (NH4+), nitrite (NO2-) and nitrate (NO3-) contents during the composting of poultry manure. The composting was carried out by adding 20% (w/w) of biochar into the mixture of poultry manure and rice straw with a ratio of 2:1, and the same treatment without biochar was prepared as a control. The finished product of control compost recorded the high contents of NO2- and NO3- (366 mg/kg and 600 mg/kg) with reduced the total NH4+ content to 10 mg/kg. Meanwhile, biochar compost recorded a higher amount of total NH4+ content (110 mg/kg) with low NO2- and NO3- (161 mg/kg and 137 mg/kg) content in the final composting material. The principal component analysis showed that the dynamics of dominant genera related to Halomonas, Pusillimonas, and Pseudofulvimonas, all of which were known as nitrifying and denitrifying bacteria, was significantly correlated with the dynamic of NO2- and NO3- content throughout the composting process. The genera related to Pusillimonas, and Pseudofulvimonas appeared as the dominant communities as the NO2- and NO3- increased. In contrast, as the NO2- and NO3- concentration decreased, the Halomonas genus were notably enriched in biochar compost. This study revealed the bacterial community shifts corresponded with the change of physicochemical properties, which provides essential information for a better understanding of monitoring and improving the composting process.
Determining the water quality of Bakun Reservoir 13 months after it operates at full supply level is crucial for better understanding of changes in the physicochemical parameters, which may enable the prediction of its effects on the survival of aquatic life in the reservoir. This study determined 13 physicochemical parameters at six stations within the reservoir at fixed depths. The results showed that the minimum 5 mg/L of dissolved oxygen (DO) required for sensitive aquatic organisms was recorded at 6 m depth. However, DO was not detectable at depths exceeding 7 m. The water was acidic at depths of more than 10 m. Turbidity and total suspended solids increased corresponding with depth. Inorganic nitrogen were predominantly in the form of ammonia-nitrogen, creating an unhealthy environment for aquatic life. Concentration of Chl-a was significantly higher at the subsurface water than 30 m depth in four out of six stations. The present study shows changes in water quality as compared to the pre-impounded period and 15 months after the filling phase, in particular, stratification of dissolved oxygen, thermocline conditions and alkalinity. The changes varied according to the distance from the dam and may have been influenced by existing land developments within the area such as the construction of the Murum Hydroelectric Dam, oil palm plantations and timber concessionares. Though the water quality might have deteriorated, further study is needed to determine if this condition will prolong.
This study investigates the spatial variation of water quality parameters in Sungai Setiu Basin at ten different locations from March 2010 to February 2011. The water quality was assessed using the Water Quality Index by Malaysian Department of Environment (DOE-WQI) and classified according to the Malaysia Interim National Water Quality Standard (INWQS). Six water quality parameters embedded in the DOE-WQI were dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), pH, ammoniacal nitrogen (AN) and total suspended solid (TSS). In addition, this study also examined the changes in water quality over the past 10 years by comparing the present water quality to the previous works. The overall mean WQI value obtained was 84.0 which indicate that the Sungai Setiu basin is in clean condition and all measured water quality parameters gave value within the permissible limits of the INWQS classification except for pH which fall in Class III. It can be concluded that water quality in Sungai Setiu does not varies greatly over a decade. Hence continuous monitoring is needed to improve the water quality and minimize water pollution.
Dialysis adequacy is conventionally quantified as net urea clearance. Single pool (sp) Kt/Vurea remains the best studied measure of dialysis adequacy globally. Other measures such as fluid status control, anemia correction, and mineral metabolism are monitored variably. Increasing use of hemodiafiltration across Europe and many parts of Japan and Australia is predicated on studies showing better patient survival with middle molecule clearance. Apart from local clinical practice guidelines, the income level and public health policy of a country determine quality of dialysis services. Among developed nations, small solute clearance adequacy targets are achieved with high frequency. In the United States, dialysis adequacy target is met by focussing on high blood flow rates and large dialyzer size, sometimes at the cost of session time. In Japan, Australia, and Germany, session length is given importance. Dialysis adequacy reporting is restricted and inconsistent in developing nations. The Gulf Cooperation Council countries, Russia and Malaysia, respectively, are close to achieving dialysis adequacy target (spKt/Vurea ≥1.2) universally in their dialysis populations. Patient-reported outcomes are typically measured only in developed countries. Patient survival on dialysis, partly linked to dialysis adequacy, varies greatly around the world, with Japan having the best survival rates. Until the development of better markers of dialysis adequacy, universal consistency in reporting of conventional parameters with a focus on patient-reported measures should be endeavored.
The simultaneous partial nitritation, anammox, denitrification, and COD oxidation (SNADCO) method was successfully carried out in an air-lift moving bed biofilm reactor (AL-MBBR) with cylinders carriers for the treatment of digested fish processing wastewater (FPW). Synthetic wastewater was used as substrate at stage 1. It changed into the digested FPW with dilution variation in order to increase the nitrogen and COD loading rates. With influent concentration of NH4+-N of 909 ± 101 mg-N/L and COD of 731 ± 26 mg/L, the nitrogen removal efficiency was 86.8% (nitrogen loading rate of 1.21 g-TN/L/d) and the COD removal efficiency was 50.5% (COD loading rate at 0.98 g-COD/L/d). This study showed that the process has the advantages in treating the real high ammonia concentration of digested wastewater containing organic compounds. The nitritation and anammox route was predominant in nitrogen removal, while COD oxidation and microbe proliferation played the main role in COD removal.
Landfill leachate is a liquid generated due to rainwater percolation through the waste in a landfill or dumping site that may contain high levels of organic matter, both biodegradable and non-biodegradable, which are the major sources of water pollution. Chemical oxygen demand (COD) and Ammoniacal Nitrogen (NH3-N) contents have been relevant indicators of severity and pollution potential of landfill leachate. The reductions of COD and NH3-N were investigated in this study using different combinations of media ratios of green mussel (GM) and zeolite (ZEO). Generally, ZEO is considered as a renowned adsorbent but with a relatively high in cost. In Malaysia, mussel shell is abundantly available as a by-product from the seafood industry, is regarded as waste, and is mostly left at the dumpsite to naturally deteriorate. Its quality and availability make GMs a cost-effective material. In this research study, leachate samples were characterized and found to contain high concentrations of COD and NH3-N. The adsorption process was conducted to find out the best combination media ratio between GM and ZEO. The removing efficiency was determined at different amounts of composite media ratios. The optimal adsorbent mixture ratios between (GM: ZEO) of 1.0:3.0 and 1.5:2.5 were considered as a more efficient technique in removing COD and NH3-N compared to exploiting these adsorbents individually. The optimal extenuation removal reduction was found at an approximately 65% of COD and 78% of NH3-N. The adsorption Isotherm Langmuir model exhibited a better fit with high regression coefficient for COD (R2 = 0.9998) and NH3-N (R2 = 0.9875), respectively. This means that the combination of GM: ZEO adsorption of landfill leachate in this analysis is homogeneous with the monolayer. The mixture of GMs and ZEO was observed to provide an alternative medium for the reduction of COD and NH3-N with comparatively lower cost.Implications: The concentration of organic constituents (COD) and ammoniacal nitrogen in stabilized landfill leachate have significantly strong influences of human health and the environment. The combination of mixing media green mussel and zeolite adsorbent enhancing organic constituents (COD) and ammoniacal nitrogen reduction efficiency from leachate. This would be greatly applicable in future research as well as conventionally minimizing high cost materials like zeolite, thereby lowering the operating cost of leachate treatment.
The present work demonstrates the coupling of titanium dioxide, TiO2 nanoparticles (TNP) with N-doped, Bi-doped, and N-Bi co-doped rice husk-derived carbon dots (CDs) via a facile dispersion method, forming respective photocatalyst composites of CDs/TNP, N-CDs/TNP, Bi-CDs/TNP and N-Bi-CDs/TNP. Characterization analyzes verified the successful incorporation of respective CDs samples into TNP, forming photocatalyst composite with narrowed band gap and quenched photoluminescence intensity. Photocatalytic activity of TNP and the respective composites was investigated for photodegradation of diclofenac (DCF) under both simulated sunlight and natural sunlight irradiation. The as-prepared N-Bi-CDs/TNP composite showed the best photocatalytic performance among all composites, able to completely degrade 5 ppm of DCF within 60 min and 180 min under both types of visible light irradiation, respectively. The N-Bi-CDs/TNP composite also showed a TOC removal efficiency up to 87.63%. N-Bi-CDs, worked as photosensitizer and electron reservoir, contributed to the outstanding photocatalytic activity of N-Bi-CDs/TNP, whereby the recombination was prolonged and light absorption was shifted towards the visible light region. Furthermore, the composite of N-Bi-CDs/TNP also demonstrated good stability and reusability over repeated degradation cycles. The photodegradation of DCF resulted into several intermediates, which were identified from LC-MS analysis. The present work could provide an insight on the application of heteroatoms doped and co-doped carbon dots in semiconductor oxide as high performance photocatalysts.
Application of urea manufacturing wastewater to teak (Tectona grandis) trees, a fast growing tropical timber plants, is an environmentally-friendly and cost-effective alternative for treatment of nitrogen-rich wastewater. However, the plant growth is strongly limited by lack of phosphorus (P) and potassium (K) elements when the plants are irrigated with wastewater containing high concentration of nitrogen (N). A greenhouse experiment was conducted to optimize the efficiency of teak-based remediation systems in terms of nutrient balance. Twelve test solutions consisted of 4 levels of P (95, 190, 570, 1140 mgL-1) and 3 levels of K (95, 190, 570 mgL-1) with a constant level of N (190 mgL-1) were applied to teak seedlings every four days during the study period. Evapotranspiration rate, nutrient removal percentage, leaf surface area, dry weight and nutrient contents of experimental plants were determined and compared with those grown in control solution containing only N (N:P:K = 1:0:0). Teak seedlings grown in units with 1:0.5:1 N:P:K ratio were highly effective at nutrient removal upto 47%, 48% and 49% for N, P and K, respectively. Removal efficiency of teak plants grown in other experimental units decreased with increasing P and K concentrations in test solutions. The lowest nutrient removal and plant growth were recorded in units with 1:6:0.5 N:P:K ratio which received the highest ratio of P to K. The findings indicated that teak seedlings functioned effectively as phytoremediation plants for N-rich wastewater treatment when they were being supplied with proper concentrations of P and K.
Graphitic carbon nitride (g-C3N4) has been regarded as a promising visible light-driven photocatalyst ascribable to its tailorable structures, thermal stability and chemical inertness. Enhanced photocatalytic activity is achievable by the construction of homojunction nanocomposites to reduce the undesired recombination of photogenerated charge carriers. In the present work, a novel g-C3N4/g-C3N4 metal-free homojunction photocatalyst was synthesized via hydrothermal polymerization. The g-C3N4/g-C3N4 derived from urea and thiourea demonstrated admirable photocatalytic activity towards rhodamine B (RhB) degradation upon irradiation of an 18 W LED light. The viability of the photoreaction with a low-powered excitation source highlighted the economic and environmental benefits of the process. The optimal g-C3N4/g-C3N4 homojunction photocatalyst exhibited a 2- and 1.8-fold increase in efficiency in relative to pristine g-C3N4 derived from urea and thiourea respectively. The enhanced photocatalytic performance is credited to the improved interfacial transfer and separation of electron-hole pairs across the homojunction interface. Furthermore, an excellent photochemical stability and durability is displayed by g-C3N4/g-C3N4 after three consecutive cycles. In addition, a plausible photocatalytic mechanism was proposed based on various scavenging tests. Overall, experimental results generated from this study is expected to intrigue novel research inspirations in developing metal-free homojunction photocatalysts to be feasible for large-scale wastewater treatment without compromising economically. Graphical abstract.
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.
Nodules harboring nitrogen-fixing rhizobia are a well-known trait of legumes, but nodules also occur in other plant lineages, with rhizobia or the actinomycete Frankia as microsymbiont. It is generally assumed that nodulation evolved independently multiple times. However, molecular-genetic support for this hypothesis is lacking, as the genetic changes underlying nodule evolution remain elusive. We conducted genetic and comparative genomics studies by using Parasponia species (Cannabaceae), the only nonlegumes that can establish nitrogen-fixing nodules with rhizobium. Intergeneric crosses between Parasponia andersonii and its nonnodulating relative Trema tomentosa demonstrated that nodule organogenesis, but not intracellular infection, is a dominant genetic trait. Comparative transcriptomics of P. andersonii and the legume Medicago truncatula revealed utilization of at least 290 orthologous symbiosis genes in nodules. Among these are key genes that, in legumes, are essential for nodulation, including NODULE INCEPTION (NIN) and RHIZOBIUM-DIRECTED POLAR GROWTH (RPG). Comparative analysis of genomes from three Parasponia species and related nonnodulating plant species show evidence of parallel loss in nonnodulating species of putative orthologs of NIN, RPG, and NOD FACTOR PERCEPTION Parallel loss of these symbiosis genes indicates that these nonnodulating lineages lost the potential to nodulate. Taken together, our results challenge the view that nodulation evolved in parallel and raises the possibility that nodulation originated ∼100 Mya in a common ancestor of all nodulating plant species, but was subsequently lost in many descendant lineages. This will have profound implications for translational approaches aimed at engineering nitrogen-fixing nodules in crop plants.
Untreated landfill leachate can harm the environment and human health due to its organic debris, heavy metals, and nitrogen molecules like ammonia. Microbial fuel cells (MFCs) have emerged as a promising technology for treating landfill leachate and generating energy. However, high concentrations of total ammonia-nitrogen (TAN), which includes both ammonia and the ammonium ion, can impede MFC performance. Therefore, maintaining an adequate TAN concentration is crucial, as both excess and insufficient levels can reduce power generation. To evaluate the worldwide research on MFCs using landfill leachate as a substrate, bibliometric analysis was conducted to assess publication output, author-country co-authorship, and author keyword co-occurrence. Scopus and Web of Science retrieved 98 journal articles on this topic during 2011-2022; 18 were specifically evaluated and analysed for MFC ammonia inhibition. The results showed that research on MFC using landfill leachate as a substrate began in 2011, and the number of related papers has consistently increased every 2 years, totaling 4060 references. China, India, and the USA accounted for approximately 60% of all global publications, while the remaining 40% was contributed by 70 other countries/territories. Chongqing University emerged as one of the top contributors among this subject's ten most productive universities. Most studies found that maintaining TAN concentrations in the 400-800 mg L-1 in MFC operation produced good power density, pollution elimination, and microbial acclimatization. However, the database has few articles on MFC and landfill leachate; MFC ammonia inhibition remains the main factor impacting system performance. This bibliographic analysis provides excellent references and future research directions, highlighting the current limitations of MFC research in this area.