MyMedR

Displaying publications 81 - 100 of 160 in total

Abstract:

Sort:

Aqueous ammonia pretreatment, saccharification, and fermentation evaluation of oil palm fronds for ethanol production

Jung YH, Kim S, Yang TH, Lee HJ, Seung D, Park YC, et al.

Bioprocess Biosyst Eng, 2012 Nov;35(9):1497-503.
PMID: 22644062 DOI: 10.1007/s00449-012-0739-8

Oil palm fronds are the most abundant lignocellulosic biomass in Malaysia. In this study, fronds were tested as the potential renewable biomass for ethanol production. The soaking in aqueous ammonia pretreatment was applied, and the fermentability of pretreated fronds was evaluated using simultaneous saccharification and fermentation. The optimal pretreatment conditions were 7 % (w/w) ammonia, 80 °C, 20 h of pretreatment, and 1:12 S/L ratio, where the enzymatic digestibility was 41.4 % with cellulase of 60 FPU/g-glucan. When increasing the cellulase loading in the hydrolysis of pretreated fronds, the enzymatic digestibility increased until the enzyme loading reached 60 FPU/g-glucan. With 3 % glucan loading in the SSF of pretreated fronds, the ethanol concentration and yield based on the theoretical maximum after 12 and 48 h of the SSF were 7.5 and 9.7 g/L and 43.8 and 56.8 %, respectively. The ethanol productivities found at 12 and 24 h from pretreated fronds were 0.62 and 0.36 g/L/h, respectively.

Matched MeSH terms: Ammonia/chemistry*
Dual function of Lemna minor and Azolla pinnata as phytoremediator for Palm Oil Mill Effluent and as feedstock

Kadir AA, Abdullah SRS, Othman BA, Hasan HA, Othman AR, Imron MF, et al.

Chemosphere, 2020 Nov;259:127468.
PMID: 32603966 DOI: 10.1016/j.chemosphere.2020.127468

In this study, two native duckweeds (Lemna minor and Azolla pinnata) were cultivated in Palm Oil Mill Effluent (POME) to extract nutrients from the effluent. Five grams of A. pinnata and 2 g of L. minor were transferred to 2 L POME (Initial concentrations: 198 mg/L COD, 4.3 mg/L nitrates, pH 9.53, 4 mg/L phosphate, 2.98 mg/L ammonia) with four different dilutions (2.5%, 5%, 10%, 15%) under greenhouse conditions. Samples of POME were taken every two days up to 10 days. Growth parameter, phosphate, ammonia, nitrates, pH, and COD were monitored within 10 days to select the most suitable growth medium for both plants. Results showed that 2.5% POME dilution had positive effect on L. minor growth and A. pinnata (wet weight increased by 8.7 g and 9.8 g, respectively), with all plants able to survive until the final day of exposure. The highest removal of ammonia was accomplished in 5% POME dilution by A. pinnata (98%) and L. minor (95.5%). The maximum phosphate removal was obtained in 10% POME dilution with 93.3% removal by A. pinnata and 86.7% by L. minor. Significant COD removal in 15% POME was obtained by L. minor (78%) and A. pinnata (66%). Both plants responded positively to the phytoremediation process, especially for A. pinnata which showed significant decreases in all parameters. The nutrient extraction by both plants from POME showed a positive effect on growth parameter, which has further promising potential to be used as animal feedstock.

Matched MeSH terms: Ammonia
Effect of the number of Cyperus rotundus and medium height on the performance of batch-constructed wetland in treating aquaculture effluent

Imron MF, Hestianingsi WOA, Putranto TWC, Citrasari N, Abdullah SRS, Hasan HA, et al.

Chemosphere, 2024 Apr;353:141595.
PMID: 38438021 DOI: 10.1016/j.chemosphere.2024.141595

Increasing aquaculture cultivation produces large quantities of wastewater. If not handled properly, it can have negative impacts on the environment. Constructed wetlands (CWs) are one of the phytoremediation methods that can be applied to treat aquaculture effluent. This research was aimed at determining the performance of Cyperus rotundus in removing COD, BOD, TSS, turbidity, ammonia, nitrate, nitrite, and phosphate from the batch CW system. Treatment was carried out for 30 days with variations in the number of plants (10, 15, and 20) and variations in media height (10, 12, and 14 cm). The result showed that aquaculture effluent contains high levels of organic compounds and nutrients, and C. rotundus can grow and thrive in 100% of aquaculture effluent. Besides that, the use of C. rotundus in CWs with the effect of numbers of plants and media height showed performance of COD, BOD, TSS, turbidity, ammonia, nitrate, nitrite, and phosphate with 70, 79, 90, 96, 64, 82, 92, and 48% of removal efficacy, respectively. There was no negative impact observed on C. rotundus growth after exposure to aquaculture effluent, as indicated by the increase in wet weight, dry weight, and growth rate when compared to the control. Thus, adding aquaculture effluent to CWs planted with C. rotundus supports the growth and development of plants while also performing phytoremediation.

Matched MeSH terms: Ammonia
Simultaneous removal of toxic ammonia and lettuce cultivation in aquaponic system using microwave pyrolysis biochar

Su MH, Azwar E, Yang Y, Sonne C, Yek PNY, Liew RK, et al.

J Hazard Mater, 2020 Sep 05;396:122610.
PMID: 32298865 DOI: 10.1016/j.jhazmat.2020.122610

This study examined an aquaponic approach of circulating water containing ammonia excretions from African catfish grown in an aquaculture tank for bacterial conversion into nitrates, which then acted as a nutrient substance to cultivate lettuce in hydroponic tank. We found that microwave pyrolysis biochar (450 g) having microporous (1.803 nm) and high BET surface area (419 m2/g) was suitable for use as biological carrier to grow nitrifying bacteria (63 g of biofilm mass) that treated the water quality through removing the ammonia (67%) and total suspended solids (68%), resulting in low concentration of remaining ammonia (0.42 mg/L) and total suspended solid (59.40 mg/L). It also increased the pH (6.8), converted the ammonia into nitrate (29.7 mg/L), and increased the nitrogen uptake by the lettuce (110 mg of nitrogen per plant), resulting in higher growth in lettuce (0.0562 %/day) while maintaining BOD5 level (3.94 mg/L) at acceptable level and 100% of catfish survival rate. Our results demonstrated that microwave pyrolysis biochar can be a promising solution for growing nitrifying bacteria in aquaponic system for simultaneous toxic ammonia remediation and generation of nitrate for growing vegetable in aquaculture industry.

Matched MeSH terms: Ammonia*
Distribution and behaviour of nitrogen compounds in the surface water of the Sungai Terengganu estuary, southern waters of South China sea, Malaysia

Suhaimi Suratman, Azyyati Abdul Aziz, Norhayati Mohd Tahir, Lee HL

Sains Malaysiana, 2018;47:651-659.

A study was carried out to determine the distribution and behaviour of nitrogen (N) compounds (nitrite, nitrate, ammonia,
dissolved and particulate organic nitrogen) in Sungai Terengganu estuary (TRE). Surface water samples were collected
during ebb neap and spring tides for the longitudinal survey along the salinity gradient. The results indicated that all N
compounds behave non-conservatively with addition during both tidal cycles, except for nitrate which exhibited removal
behaviour during spring tide. In general, higher concentration of N compounds was observed during spring tide compared
to neap tide. It is suggested that during spring tide, stronger water turbulence resulted in resuspension of nutrients in
bottom sediment and lead to the increase in N compounds concentrations in the surface water. The diurnal survey for the
freshwater station showed that the concentrations of N compounds follow the ebb and flood variations, whereas for the
coastal station the reverse trend was observed. Comparisons with a previous study under similar tidal conditions show
there was an increase in nitrite and ammonia concentrations in TRE, which was probably due to increase in discharge
from the rapid development activities around this area. In addition, the presence of a breakwater at the lower part of
the estuary may also contribute to the high nutrient content in the estuary due to restricted outflow of nutrients to the
coastal area. Overall, the results from this study highlighted the importance of monitoring the N compounds for future
protection of the estuary.

Matched MeSH terms: Ammonia
Etiology, outcome and prognostic indicators of acute liver failure in Asian children

Ng RT, Chew KS, Choong CL, Song ZL, Teh JKL, Koay ZL, et al.

Hepatol Int, 2022 Dec;16(6):1390-1397.
PMID: 36131224 DOI: 10.1007/s12072-022-10417-5

OBJECTIVE: Outcome of pediatric acute liver failure (PALF) in countries with limited availability of LT is not well described. We evaluated the outcome and prognostic indicators of PALF in Malaysia where emergency LT for ALF is limited.
METHODS: In this retrospective review on children ammonia, total bilirubin) and upon admission (aLIU) on outcome of PALF was evaluated using receiver operator characteristic (ROC) curves.
RESULTS: Of 77 children (39 males [51%]; median age 2.8 years) with PALF, the overall survival was 55% (n = 42); 52% (n = 40) survived with supportive management, 2.6% (n = 2) after LT. As compared to children who survived without LT, children who had LT/died had lower hemoglobin, aspartate transferase, γ-glutamyl transpeptidase (GGT), and higher serum bilirubin, alkaline phosphatase, ammonia, and serum sodium (p 452 μmol/L and peak GGT

Matched MeSH terms: Ammonia
Effect of aquaculture salinity on nitrification and microbial community in moving bed bioreactors with immobilized microbial granules

Gao Y, Wang X, Li J, Lee CT, Ong PY, Zhang Z, et al.

Bioresour Technol, 2020 Feb;297:122427.
PMID: 31784249 DOI: 10.1016/j.biortech.2019.122427

The novel immobilized microbial granules (IMG) shows a significant effect of nitrification for freshwater aquaculture. However, there is lack of evaluation study on the performance of nitrification at high salinity due to the concentration of recycled water or seawater utilization. A laboratory scale moving bed bioreactor (MBBR) with IMG was tested on recycled synthetic aquaculture wastewater for the nitrification at 2.5 mg/L NH3-N daily. The results indicated that IMG showed a high salinity tolerance and effectively converted ammonia to nitrate up to 92% at high salinity of 35.0 g/L NaCl. As salinity increased from near zero to 35.0 g/L, the microbial activity of nitrite oxidation bacteria (NOB) in the IMG decreased by 86.32%. The microbial community analysis indicated that salinity significantly influenced the community structure. It was found that Nitrosomonas sp. and Nitrospira sp. were the dominant genera for ammonia oxidation bacteria (AOB) and NOB respectively at different salinity levels.

Matched MeSH terms: Ammonia
Diel osmorespiration rhythms of juvenile marble goby (Oxyeleotris marmorata)

Lim LS, Tan SY, Tuzan AD, Kawamura G, Mustafa S, Rahmah S, et al.

Fish Physiol Biochem, 2020 Aug;46(4):1621-1629.
PMID: 32430644 DOI: 10.1007/s10695-020-00817-5

Oxyeleotris marmorata is an ambush predator. It is known for slow growth rate and high market demand. Farming of O. marmorata still remains a challenge. In order to establish a proper feeding practice to stimulate growth, knowledge of its metabolic processes and cost should be examined. Therefore, this study was designed to investigate the diel osmorespiration rhythms of O. marmorata in response to feeding challenge by using an osmorespirometry assay. The results have shown that oxygen consumption rate of the fed fish was approximately 3 times higher than that of the unfed fish in early evening to support specific dynamic action. Digestion and ingestion processes were likely to be completed within 18-20 h in parallel with the ammonia excretion noticeable in early morning. Under resting metabolism, metabolic oxygen consumption was influenced by diel phase, but no effect was noted in ammonia excretion. As a nocturnal species, O. marmorata exhibited standard aerobic metabolic mode under dark phase followed by light phase, with high oxygen consumption rate found in either fed or unfed fish. It can be confirmed that both the diel phase and feeding have a significant interactive impact on oxygen consumption rate, whereas ammonia metabolism is impacted by feeding state. High metabolic rate of O. marmorata supports the nocturnal foraging activity in this fish. This finding suggested that feeding of O. marmorata should be performed during nighttime and water renewal should be conducted during daytime.

Matched MeSH terms: Ammonia/metabolism
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: Ammonia/analysis
Plant growth promoting and antifungal asset of indigenous rhizobacteria secluded from saffron (Crocus sativus L.) rhizosphere

Rasool A, Imran Mir M, Zulfajri M, Hanafiah MM, Azeem Unnisa S, Mahboob M

Microb Pathog, 2021 Jan;150:104734.
PMID: 33429050 DOI: 10.1016/j.micpath.2021.104734

Saffron (Crocus sativus L.) is an important plant in medicine. The Kashmir Valley (J&K, India) is one of the world's largest and finest saffron producing regions. However, over the past decade, there has been a strong declining trend in saffron production in this area. Plant Growth Promoting Rhizobacteria (PGPR) are free living soil bacteria that have ability to colonize the surfaces of the roots and ability to boost plant growth and development either directly or indirectly. Using the efficient PGPR as a bio-inoculant is another sustainable agricultural practice to improve soil health, grain yield quality, and biodiversity conservation. In the present study, a total of 13 bacterial strains were isolated from rhizospheric soil of saffron during the flowering stage of the tubers and were evaluated for various plant growth promoting characteristics under in vitro conditions such as the solubilization of phosphate, production of indole acetic acid, siderophore, hydrocyanic acid, and ammonia production and antagonism by dual culture test against Sclerotium rolfsii and Fusarium oxysporum. All the isolates were further tested for the production of hydrolytic enzymes such as protease, lipase, amylase, cellulase, and chitinase. The maximum proportions of bacterial isolates were gram-negative bacilli. About 77% of the bacterial isolates showed IAA production, 46% exhibited phosphate solubilization, 46% siderophore, 61% HCN, 100% ammonia production, 69% isolates showed protease activity, 62% lipase, 46% amylase, 85% cellulase, and 39% showed chitinase activity. Three isolates viz., AIS-3, AIS-8 and AIS-10 were found to have the most plant growth properties and effectively control the growth of Sclerotium rolfsii and Fusarium oxysporum. The bacterial isolates were identified as Brevibacterium frigoritolerans (AIS-3), Alcaligenes faecalis subsp. Phenolicus (AIS-8) and Bacillus aryabhattai (AIS-10) respectively by 16S rRNA sequence analysis. Therefore, these isolated rhizobacterial strains could be a promising source of plant growth stimulants to increase cormlets growth and increase saffron production.

Matched MeSH terms: Ammonia
Nutrient removal in a pilot and full scale constructed wetland, Putrajaya city, Malaysia

Sim CH, Yusoff MK, Shutes B, Ho SC, Mansor M

J Environ Manage, 2008 Jul;88(2):307-17.
PMID: 17467147

Putrajaya Wetlands in Malaysia, a 200ha constructed wetland system consisting of 24 cells, was created in 1997-1998 to treat surface runoff caused by development and agricultural activities from an upstream catchment before entering Putrajaya Lake (400ha). It was designed for stormwater treatment, flood control and amenity use. The water quality improvement performance of a section of the wetland cells is described. The nutrient removal performance was 82.11% for total nitrogen, 70.73% for nitrate-nitrogen and 84.32% for phosphate, respectively, along six wetland cells from Upper North UN6 to UN1 from April to December 2004. Nutrient removal in pilot scale tank systems, simulating a constructed wetland and planted with examples of common species at Putrajaya, the Common Reed Phragmites karka and Tube Sedge Lepironia articulata, and the capacity of these species to retain nutrients in above and below-ground plant biomass and substrate is reported. The uptake of nutrients by the Common Reed and Tube Sedge from the pilot tank system was 42.1% TKN; 28.9% P and 17.4% TKN; 26.1% P, respectively. The nutrient uptake efficiency of the Common Reed was higher in above-ground than in below-ground tissue. The results have implications for plant species selection in the design of constructed wetlands in Malaysia and for optimizing the performance of these systems.

Matched MeSH terms: Ammonia/chemistry
Minimum ignition energies and laminar burning velocities of ammonia, HFO-1234yf, HFC-32 and their mixtures with carbon dioxide, HFC-125 and HFC-134a

Sadaghiani MS, Arami-Niya A, Zhang D, Tsuji T, Tanaka Y, Seiki Y, et al.

J Hazard Mater, 2021 04 05;407:124781.
PMID: 33412363 DOI: 10.1016/j.jhazmat.2020.124781

Given the safety issues associated with flammability characteristics of alternative environmentally-friendly refrigerants, it is vital to establish measurement systems to accurately analyse the flammability of these mildly flammable refrigerants. In this study, we used a customised Hartmann bomb analogue to measure the minimum ignition energy (MIE) and laminar burning velocity (BV) for refrigerant/air mixtures of pure ammonia (R717), R32, R1234yf and mixtures of R32 and R1234yf with non-flammable refrigerants of R134a, R125 and carbon dioxide (R744). The MIEs of R717, R32, and R1234yf were measured at an ambient temperature of 24 °C to be (18.0 ± 1.4), (8.0 ± 1.5) and (510 ± 130) mJ at equivalence ratios of 0.9, 1.27 and 1.33, respectively. Adding the non-flammable refrigerants R134a, R125 and R744 along with R32 at volumetric concentrations of 5% each to R1234yf reduced the latter compound's flammability and increased its MIE by one order of magnitude. The laminar burning velocities of pure R717 and R32 were measured at an equivalence ratio of 1.1 using the flat flame method and found to be 8.4 and 7.4 cm/s, respectively. Adding 5% R1234yf to R32 decreased the laminar burning velocity by 11%, while a further 5% addition of R1234yf resulted in a decrease of over 30% in the laminar burning velocity.

Matched MeSH terms: Ammonia
Fulltext Global serum metabolomics profiling of colorectal cancer

Hashim NAA, Ab-Rahim S, Suddin LS, Saman MSA, Mazlan M

Molecular and clinical oncology, 2019 Jul;11(1):3-14.
PMID: 31289671 DOI: 10.3892/mco.2019.1853

Accurate diagnosis of colorectal cancer (CRC) relies on the use of invasive tools such as colonoscopy and sigmoidoscopy. Non-invasive tools are less sensitive in detecting the disease, particularly in the early stage. A number of researchers have used metabolomics analyses on serum/plasma samples of patients with CRC compared with normal healthy individuals in an effort to identify biomarkers for CRC. The aim of the present review is to compare reported serum metabolomics profiles of CRC and to identify common metabolites affected among these studies. A literature search was performed to include any experimental studies on global metabolomics profile of CRC using serum/plasma samples published up to March 2018. The Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool was used to assess the quality of the studies reviewed. In total, nine studies were included. The studies used various analytical platforms and were performed on different populations. A pathway enrichment analysis was performed using the data from all the studies under review. The most affected pathways identified were protein biosynthesis, urea cycle, ammonia recycling, alanine metabolism, glutathione metabolism and citric acid cycle. The metabolomics analysis revealed levels of metabolites of glycolysis, tricarboxylic acid cycle, anaerobic respiration, protein, lipid and glutathione metabolism were significantly different between cancer and control samples. Although the majority of differentiating metabolites identified were different in the different studies, there were several metabolites that were common. These metabolites include pyruvic acid, glucose, lactic acid, malic acid, fumaric acid, 3-hydroxybutyric acid, tryptophan, phenylalanine, tyrosine, creatinine and ornithine. The consistent dysregulation of these metabolites among the different studies suggest the possibility of common diagnostic biomarkers for CRC.

Matched MeSH terms: Ammonia
VFA and ammonia from residential food waste as indicators of odor potential

Qamaruz-Zaman N, Milke MW

Waste Manag, 2012 Dec;32(12):2426-30.
PMID: 22819598 DOI: 10.1016/j.wasman.2012.06.023

Research was conducted to determine suitable chemical parameters as indicators of odor from decomposing food wastes. Prepared food scraps were stored in 18 l plastic buckets (2 kg wet weight each) at 20 °C and 8 °C to reproduce high and low temperature conditions. After 1, 3, 7, 10 and 14 days of storage, the odor from the buckets were marked to an intensity scale of 0 (no odor) to 5 (intense) and the corresponding leachate analyzed for volatile fatty acids, ammonia and total organic carbon. A linear relationship between odor intensity and the measured parameter indicates a suitable odor indicator. Odor intensified with longer storage period and warmer surroundings. The study found ammonia and isovaleric acid to be promising odor indicators. For this food waste mixture, offensive odors were emitted if the ammonia and isovaleric acid contents exceeded 360 mg/l and 940 mg/l, respectively.

Matched MeSH terms: Ammonia/chemistry*
Fulltext Impact of soil field water capacity on secondary metabolites, phenylalanine ammonia-lyase (PAL), maliondialdehyde (MDA) and photosynthetic responses of Malaysian kacip fatimah (Labisia pumila Benth)

Jaafar HZ, Ibrahim MH, Mohamad Fakri NF

Molecules, 2012 Jun 13;17(6):7305-22.
PMID: 22695235 DOI: 10.3390/molecules17067305

A randomized complete block design 2 × 4 experiment was designed and conducted for 15 weeks to characterize the relationships between production of total phenolics, flavonoid, anthocyanin, leaf gas exchange, total chlorophyll, phenylalanine ammonia-lyase (PAL) and malondialdehyde (MDA) activity in two varieties of Labisia pumila Benth, namely the var. alata and pumila, under four levels of evapotranspiration replacement (ER) (100%; well watered), (75%, moderate water stress), (50%; high water stress) and (25%; severe water stress). The production of total phenolics, flavonoids, anthocyanin, soluble sugar and relative leaf water content was affected by the interaction between varieties and SWC. As the ER levels decreased from 100% to 25%, the production of PAL and MDA activity increased steadily. At the highest (100%) ER L. pumila exhibited signiﬁcantly higher net photosynthesis, apparent quantum yield, maximum efficiency of photosystem II (f(v)/f(m)) and lower dark respiration rates compared to the other treatment. The production of total phenolics, flavonoids and anthocyanin was also found to be higher under high water stress (50% ER replacement) compared to severe water stress (25% ER). From this study, it was observed that as net photosynthesis, apparent quantum yield and chlorophyll content were downregulated under high water stress the production of total phenolics, flavonoids and anthocyanin were upregulated implying that the imposition of high water stress can enhance the medicinal properties of L. pumila Benth.

Matched MeSH terms: Phenylalanine Ammonia-Lyase/metabolism*
Effects of thermal stratification on the concentration of iron and manganese in a tropical water supply reservoir

Noor Halini Baharim, Razali Ismail, Mohamad Hanif Omar

Sains Malaysiana, 2011;40:1179-1186.

Thermal stratification in lakes is an important natural process that can have a significant effect on the water resource quality. The potential changes in chemical contents in water resulting from stratification are the production of ammonia, sulphides and algal nutrients and the increasing concentrations of iron and manganese. One of the water supply reservoirs located in Johor, Malaysia facing with high iron and manganese concentrations associated with the period of stratifications. This study showed that the level of thermal stratification in the reservoir varied at different time of the year. During the strongest period of stratification, the dissolved oxygen content was found to diminish significantly with depth and iron and manganese were recorded at the highest concentrations. Although significant period of rainfalls contributed to the natural destratification of reservoir, lower concentrations of iron and manganese only remained for a shorter period before the concentrations continued to increase with the onset of the thermal stratification. A good understanding on the behaviour of the reservoir may help to identify several measures for the improvement of water quality.

Matched MeSH terms: Ammonia
The effect of calcium hydroxide addition on enhancing ammonia recovery during thermophilic composting in a self-heated pilot-scale reactor

Tie HO, Che Man H, Koyama M, Syukri F, Md Yusoff F, Toda T, et al.

Waste Manag, 2023 Jul 01;166:194-202.
PMID: 37178588 DOI: 10.1016/j.wasman.2023.04.046

A modified outdoor large-scale nutrient recycling system was developed to compost organic sludge and aimed to recover clean nitrogen for the cultivation of high-value-added microalgae. This study investigated the effect of calcium hydroxide addition on enhancing NH3 recovery in a pilot-scale reactor self-heated by metabolic heat of microorganisms during thermophilic composting of dewatered cow dung. 350 kg-ww of compost was prepared at the ratio of 5: 14: 1 (dewatered cowdung: rice husk: compost-seed) in a 4 m3 cylindrical rotary drum composting reactor for 14 days of aerated composting. High compost temperature up to 67 °C was observed from day 1 of composting, proving that thermophilic composting was achieved through the self-heating process. The temperature of compost increases as microbial activity increases and temperature decreases as organic matter decreases. The high CO2 evolution rate on day 0-2 (0.02-0.08 mol/min) indicated that microorganisms are most active in degrading organic matter. The increasing conversion of carbon demonstrated that organic carbon was degraded by microbial activity and emitted as CO2. The nitrogen mass balance revealed that adding calcium hydroxide to the compost and increasing the aeration rate on day 3 volatilized 9.83 % of the remaining ammonium ions in the compost, thereby improving the ammonia recovery. Moreover, Geobacillus was found to be the most dominant bacteria under elevated temperature that functions in the hydrolysis of non-dissolved nitrogen for better NH3 recovery. The presented results show that by thermophilic composting 1 ton-ds of dewatered cowdung for NH3 recovery, up to 11.54 kg-ds of microalgae can be produced.

Matched MeSH terms: Ammonia/analysis
Integrated nutrient recycling: Ammonia recovery from thermophilic composting of shrimp aquaculture sludge via self-heated bench-scale reactor and mango plant growth enhancement by the compost

Tie HO, Che Man H, Koyama M, Syukri F, Md Yusoff F, Toda T, et al.

Waste Manag, 2024 May 15;180:55-66.
PMID: 38520898 DOI: 10.1016/j.wasman.2024.03.021

Due to the rapid growth of the aquaculture industry, large amounts of organic waste are released into nature and polluted the environment. Traditional organic waste treatment such as composting is a time-consuming process that retains the ammonia (NH3) in the compost, and the compost produced has little economic value as organic fertilizer. Illegal direct discharge into the environment is therefore widespread. This study investigates the recovery of NH3 through thermophilic composting of shrimp aquaculture sludge (SAS) and its application as a soil conditioner for the growth of mango plants. A maximum composting temperature of 57.10 °C was achieved through self-heating in a 200 L bench-scale reactor, resulting in NH3 recovery of 224.04 mol/ton-ds after 14 days. The addition of calcium hydroxide and increased aeration have been shown to increase NH3 volatilization. The recovered NH3 up to 3 kg-N can be used as a source of clean nitrogen for high-value microalgae cultivation, with a theoretical yield of up to 34.85 kg-algae of microalgae biomass from 1 ton-ds of SAS composting. Despite the high salinity, SAS compost improved mango plant growth and disease resistance. These results highlight the potential of SAS compost as a sustainable source of clean nitrogen for microalgae cultivation and soil conditioner, contributing to a waste-free circular economy through nutrient recycling and sustainable agriculture.

Matched MeSH terms: Ammonia/analysis
Condition index of meretrix lyrata (sowerby 1851) and its relationship with water parameter in Sarawak

Hadi Hamli, Mohd Hanafi Idris, Amy Halimah Rajaee, Abu Hena Mustafa Kamal, Mohammad Nesarul Hoque

Sains Malaysiana, 2017;46:545-551.

Condition Index (CI) was used to estimate the reproductive biology cycle of the hard clam Meretrix lyrata based on dry
body weight and shell weight. High CI value was observed due to the increase in the body weight of the hard clam that
corresponding to the maturity stage and early spawning. The CI value of M. lyrata from Buntal Village, Kuching, Sarawak
showed three highest peaks during the 12-month study on May and October 2013 and March 2014. The lowest CI values
were obtained in September and November 2013 and April 2014. Ammonia nitrogen was the only water parameter that
significantly correlated to the CI values. The CI application is important to estimate the maturity of hard clam gonad
to facilitate conservation activity through the hard clam harvesting out of the gonad maturation and spawning period.

Matched MeSH terms: Ammonia
Effects of changes in chemical and structural characteristic of ammonia fibre expansion (AFEX) pretreated oil palm empty fruit bunch fibre on enzymatic saccharification and fermentability for biohydrogen

Abdul PM, Jahim JM, Harun S, Markom M, Lutpi NA, Hassan O, et al.

Bioresour Technol, 2016 Jul;211:200-8.
PMID: 27017130 DOI: 10.1016/j.biortech.2016.02.135

Oil palm empty fruit bunch (OPEFB) fibre is widely available in Southeast Asian countries and found to have 60% (w/w) sugar components. OPEFB was pretreated using the ammonia fibre expansion (AFEX) method and characterised physically by the Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. The results show that there were significant structural changes in OPEFB after the pretreatment step, and the sugar yield after enzymatic hydrolysis using a cocktail of Cellic Ctec2® and Cellic Htec2® increased from 0.15gg(-1) of OPEFB in the raw untreated OPEFB sample to 0.53gg(-1) of OPEFB in AFEX-pretreated OPEFB (i.e. almost a fourfold increase in sugar conversion), which enhances the economic value of OPEFB. A biohydrogen fermentability test of this hydrolysate was carried out using a locally isolated bacterium, Enterobacter sp. KBH6958. The biohydrogen yield after 72h of fermentation was 1.68mol H2 per mol sugar. Butyrate, ethanol, and acetate were the major metabolites.

Matched MeSH terms: Ammonia

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links