Chicken Eggshell as an Innovative Bioflocculant in Harvesting Biofloc for Aquaculture Wastewater Treatment

Implementation of biofloc technology(BFT)system in aquaculture industry shows high productivity,low feed conversion ratio,and an optimum culture environment.This study was divided into two phases.The first phase involved maintaining the water quality using the optimum carbon-to-nitrogen ratio by manipulating pH in culture water.The second phase examined the performance of harvesting biofloc(remaining phytoplankton and suspended solids in the system)using chicken eggshell powder(CESP).This study showed that pH 7 to 8 were the best biofloc performance with high removal percentage of ammonia(>99%)with a remaining ammonia concentration of 0.016 mg L^(−1)and 0.018 mg L^(−1),respectively.The second phase of this study was performed to determine the optimal formulation and conditions of using CESP as a bio-flocculant in harvesting excess biofloc.The use of eggshell showed a higher harvesting efficiency of more than 80%under the following treatment conditions:0.25 g L^(−1)of eggshell dosage;with rapid and slow mixing rates of 150 and 30 rpm,respectively;30 min of settling time;settling velocity of 0.39 mm s^(−1)and pH of 6 to 7.Therefore,the results indicated that biofloc would be the best green technology approach for sustainable aquaculture wastewater and the CESP is an organic matrix that environmental-friendly bio-coagulant for biofloc harvesting.

Extraction and Characterization of Litopenaeus vannamei’s Shell as Potential Sources of Chitosan Biopolymers

Chitin is the second most abundant polysaccharide,produced mainly as an industrial waste stream during crustacean processing.Chitin can be derived into chitosan through the deacetylation process.Conversion of shrimp waste into chitosan via the deacetylation process could be considered a practical approach for shell waste remediation.In this study,chitosan’s physicochemical characteristics extracted from two types of Pacific white leg shrimp,L.vannamei’s shell(i.e.,rough and smooth),were compared with commercial chitosan.The yield,moisture,ash,solubility,water and fat binding capacity were measured.The degree of deacetylation(DDA)was calculated using FTIR,and their chemical Structure was confirmed using XRD and SEM-EDS.Both extracted chitosan showed no significant difference in yield,moisture,ash,solubility and water binding capacity but showed a significant difference with commercial chitosan.Moreover,the fat binding capacity of commercial chitosan showed the lowest percentage(408.34±0.83%)as compared to extracted chitosan(smooth shell 549.59±12.48%;rough shell 500.55±12.10%).The DDA indicated that extracted chitosan from the smooth and rough shell was considered good chitosan as compared to commercial chitosan with 84.08±1.27%,80.78±0.79%and 74.99±1.48%,respectively.Additionally,the presence of hydroxyl and amino groups from FTIR and a good crystallinity index was recorded using XRD of extracted chitosan.Based on observed characteristics,shrimp shell waste from L.vannamei can achieve chitosan standard quality as a biopolymer and highly potential to be applied in various industrial applications.

A Review of Various Sources of Chitin and Chitosan in Nature

Chitin was first discovered by its name from the Greek word“chiton”,which means“mail coat”.It is indeed a polysaccharide made up of naturally occurring acetyl-D-glucosamine monomers.Hatchett was the first researcher who extracted chitin from the shells of mollusks(crabs and lobsters),prawns,and crayfish in 1799.Later in 1811,Henri Braconnot discovered chitin in the cell walls of mushrooms and called it“fungine”.Chitin and chitosan are abundant in the biosphere as essential components of many organisms’exoskeletons and as by-products of the global seafood industry.The biopolymer must be deacetylated before chitosan can be produced.It can also be extracted using microbes in a biological extraction procedure.The development of products that take advantage of the bioactivities of the existing primary commercial source of chitin(crustacean)has lagged expectations.Also,the disadvantages of the present commercial source such as seasonality and competition for other uses among others has been one of the driving forces towards seeking alternative sources of chitin and chitosan in nature.This review highlights some of the efforts made by environmental scholars to locate possible commercial sources of chitin and chitosan in nature over time.

Growth performance,fatty acid profile,gut,and muscle histo-morphology of Malaysian mahseer,Tor tambroides post larvae fed short-term host associated probiotics

Host associated probiotics(HAPs)provide health benefits to the host when administered as dietary supplement.However,a short-term probiotics application strategy has yet to be optimized.A 90-days study was conducted to evaluate the response of Malaysian mahseer,Tor tambroides post larvae fed with basal diet enriched HAPs for 30-days,and its response following another 60-days feeding with only basal diet.Three experimental diets(Enterococcus faecalis strain 2674(T1),Aeromonas sp.strain A8-29(T2)and E.faecalis strain FC11682(T3))were prepared by spray-coating each HAPs on a basal diet at 1×108 CFU/g feed.Differences in growth performances,whole-body proximate and fatty acid composition,muscle morphometry,and gut morphology were evaluated.Results showed that after 30 days,T3 fish produced highest growth.All HAP treatment groups showed better muscle distribution profile,improved fatty acid composition,and higher villus length,width and area,than control group.After 90 days,the growth of T3 fish was still the highest.Muscle distribution profile and villus growth were higher in HAP treatments,although only total n-6 PUFA,total MUFA,linoleic acids,and linolenic acids in HAP treated fish remained high after probiotics withdrawal.No difference in whole-body proximate composition was observed in both 30 and 90 days.Collective findings demonstrated that short-term application of HAPs at an early stage could be used to boost T.tambroides growth,with E.faecalis strain FC11682 showing the best efficacy.

Recent advances in functional utilisation of environmentally friendly and recyclable high-performance green biocomposites: A review

Humans have relied on biomass for survival and development since the Stone Age. All aspects of human needs for materials are covered by tools, fuel, and buildings. Nowadays, metals and petroleum-based materials are widely used in highly developed industries. Unfortunately, environmental contamination and the loss of natural resources have led to the reemergence of biomass resources as efficient and sustainable energy sources. Notably, simple and direct applications can no longer meet the demand for functionalization, high performance of materials and construction materials. Therefore, it is imperative to modify biomass and combine its utilisation to produce functionalization and high performance materials. For example, construction materials with superior mechanical properties and water resistance can be produced by reinforcing fibres to facilitate crosslinking. Water-oil separation or adsorption effects of hydrogels and aerogels are determined by the porosity and lightness of biomass, biocomposite conductor is prepared by chimaeric conductive material. Here, we review the approaches that have been taken to devise an environmentally friendly yet fully recyclable and sustainable functionalised biocomposites from biomass and its potential directions for future research.

Thermal pyrolysis conversion of methane to hydrogen(H_(2)):A review on process parameters,reaction kinetics and techno-economic analysis

Hydrogen(H_(2))is a promising renewable energy which finds wide applications as the world gears toward low-carbon economy.However,current H_(2) production via steam methane reforming of natural gas or gasification of coal are laden with high CO_(2) footprints.Recently,methane(CH_(4))pyrolysis has emerged as a potential technology to generate low-carbon H_(2) and solid carbon.In this review,the current state-of-art and recent progress of H_(2) production from CH_(4) pyrolysis are reviewed in detail.Aspects such as funda-mental mechanism and chemistry involved,effect of process parameters on the conversion efficiency and reaction kinetics for various reaction media and catalysts are elucidated and critically discussed.Temper-ature,among other factors,plays the most critical influence on the methane pyrolysis reaction.Molten metal/salt could lower the operating temperature of methane pyrolysis to<1000℃,whereas plasma technology usually operates in the regime of>1000℃.Based on the reaction kinetics,metal-based cata-lysts were more efficient in lowering the activation energy of the reaction to 29.5-88 kJ/mol from that of uncatalyzed reaction(147-420.7 kJ/mol).Besides,the current techno-economic performance of the pro-cess reveals that the levelized cost of H_(2) is directly influenced by the sales price of carbon(by-product)generated,which could offset the overall cost.Lastly,the main challenges of reactor design for efficient product separation and retrieval,as well as catalyst deactivation/poisoning need to be debottlenecked.

Effect of Probiotics on Juvenile Tachypleus tridentatus Gut Microbiota

The population of tri-spine horseshoe crabs(HSCs)Tachypleus tridentatus has sharply decreased in recent decades.Domestication and manual releasing are now used to recover it.In order to accelerate the growth of T.tridentatus in indoor environment,in this study,gut microbiota of 2nd instar T.tridentatus was supposed to be improved by putting probiotics in water environment and thus promoted the health and growth of the host.Using 16S rRNA sequencing of gut samples,we examined the intestinal microbiome of juvenile HSCs and studied the effect of probiotics.Results showed that there was no significant difference between groups fed with high and low concentrations(1×10^(7),1×10^(12)CFU mL^(−1))of Bacillus subtilis and high concentration(1×10^(12)CFU mL^(−1))of Lactobacillus,and no significant difference compared with the control group,but the diversity of Lactobacillus group with low concentration(1×10^(7)CFU mL^(−1))was significantly higher than those of other groups.Microbial-mediated functions predicted by PICRUSt showed that‘Cellular Processes’,‘Metabolism’and‘Organismal Systems’pathways significantly increased in groups of Bacillus subtilis and Lactobacillus group with low concentration.The results showed that two types of probiotics with different concentrations have other effects on the structure,richness and function of intestinal microbes.By searching the literature and conducting pre-experiments,we forecasted the short time of breeding under the probiotic environment may not have much effect.The present study for the first time investigated the impact of probiotics on gut microbiota of juvenile HSCs and found them may benefit for the growth and health of HSCs.

Myo-inositol accelerates the metamorphosis from megalopa to crablet of Scylla paramamosain by modulating cuticle decomposition and reconstruction

The mud crab Scylla paramamosain is a key species in China due to its high nutritional value and great economic worth and has grown in popularity.Myo-inositol can modulate versatile physiological functions in aquatic animals.In the present study,S.paramamosain megalopa were given graded concentrations of myo-inositol(0,1,2,4,and 8 ppm)by water immersion to explore how their metamorphosis would be affected.The results showed that supplementing with myo-inositol remarkably increased transformation and survival rate from megalopa to crablet by at least 1.16 and 1.26 times,respectively.To decipher the molecular mechanism of how myo-inositol increases metamorphosis and survival rate,we further performed transcriptome-based gene expression profiling of both megalopa and crablet treated with myo-inositol.The integrative transcriptome analyses predicted that the differentially expressed genes(DEGs)were significantly enriched in chitinase activity,structural constituent of cuticle,and chitin binding,which are associated with the decomposition and reconstruction of cuticle.qPCR results confirmed that myo-inositol mediated gene expression levels of the above cuticle-related pathways.Considering the importance of the cuticle in exoskeleton formation and molting,it can be concluded that myo-inositol-induced changes in the cuticle decomposition and reconstruction might have accelerated the transformation from megalopa to crablet of S.paramamosain.Besides,numerous DEGs were significantly enriched in protein digestion and absorption,amino sugar and nucleotide sugar metabolism.It implies that myo-inositol may improve survival by regulating energy or nutrient absorption.Additionally,the accelerated metamorphosis by myo-inositol may improve survival from megalopa to crablet of S.paramamosain.Overall,this study will provide the first insights into the underlying molecular mechanisms by which myo-inositol increases metamorphosis and survival.

Microwave torrefaction of empty fruit bunch pellet:Simulation and validation of electric field and temperature distribution

Microwave simulation is significant in identifying a reactor design allowing the biomass to be heated and processed evenly.This study integrated the radio frequency and transient heat transfer modules to simulate the microwave distribution and investigated the performance of microwave heating in the cavity.The simulation results were compared with the experimental findings us-ing the finite element analysis software of COMSOL MULTIPHYSICS to predict the temperature profile and electric field of microwave in the biomass(empty fruit bunch pellets).The higher temperature distribution was observed at the bottom and centre section of the empty fruit bunch pellet bed in the reactor,showing the uniqueness of microwave heating.According to the simula-tion results,the temperature profile obtained through the specific cavity geometry and dielectric properties agreed with the experimental temperature profile.The simulated temperature profile demonstrated a logarithmic increase of 120°C/min at the first 50 s followed by 50°C/min until 350 s.The experimental temperature profile showed three different heating rates before reaching 300°C,including 78.3°C/min(50-120°C),30.6°C/min(121-250°C),and 105°C/min(250-300°C).The results of this study might contribute to the improvement of microwave heating in biomass torrefaction.

Microplastics pollution:Economic loss and actions needed

Microplastics originate from plastic bottles of water and soft drink,plastic bags,tire wear,plastic agricultural mulches and 3D printing[1,2].These small fragments of wastes being 1μm to 5 mm pollute the environment and threaten human health and ecosystem services including crops and others,leading to economic losses[1–3].It is predicted that by 2030,plastic productions will be leading environmental pollution in terms of carbon footprint and toxic chemicals[4],making U.S.the world’s largest plastic waste generator[5].Based on reports from the United Nations Environment Assembly(UNEA)and the United Nations Environmental Program(UNEP),plastics in the environment annually burden the global economy by$19 billion,causing concerns for long-term ecological sustainability and the Global Goals[6].It is reported that about 8.3 billion tons of plastic waste have been created,leading to 4.9 billion tons discarded through landfilling globally[7],causing a yearly financial loss of more than$13 billion[8].

The hidden risk of microplastic-associated pathogens in aquatic environments

Increasing studies of plastisphere have raised public concern about microplastics(MPs)as vectors for pathogens,especially in aquatic environments.However,the extent to which pathogens affect human health through MPs remains unclear,as controversies persist regarding the distinct pathogen colonization on MPs as well as the transmission routes and infection probability of MP-associated pathogens from water to humans.In this review,we critically discuss whether and how pathogens approach humans via MPs,shedding light on the potential health risks involved.Drawing on cutting-edge multidisciplinary research,we show that some MPs may facilitate the growth and long-range transmission of specific pathogens in aquatic environments,ultimately increasing the risk of infection in humans.We identify MP-and pathogen-rich settings,such as wastewater treatment plants,aquaculture farms,and swimming pools,as possible sites for human exposure to MP-associated pathogens.This review emphasizes the need for further research and targeted interventions to better understand and mitigate the potential health risks associated with MP-mediated pathogen transmission.

Solar-driven photothermal catalytic CO_(2) conversion:a review

It is highly desirable to seek green and sustainable technologies,such as employing photo thermal effects to drive energy catalysis processes to address the high energy demand and associated environmental impacts induced by the current methods.The photothermocatalysis process is an emerging research area with great potential in efficiently converting solar energy through various catalytic reactions.However,achieving simultaneously high conversion efficiency,cyclability,and durability is still a daunting challenge.Thus,tremendous work is still needed to enhance solar photo thermal catalytic conversion and promote its large-scale applications.This review developed the principles of coupling solar photon and thermal fields underlying the photothermal effect,exploration of efficient nanocatalysts,development of optofluidic reactor model,and photo thermal synergistic-driven CO_(2) reduction mechanisms.The ultimate goal was to provide an effective approach that can effectively convert solar energy into photocarriers/hot-electrons and heat,and importantly,can couple them to regulate catalysis reaction pathways toward the production of value-added fuel and chemical energy.

A review of gynogenesis manipulation in aquatic animals

Gynogenesis is an established technique to generate all female type offspring and this technique has been successfully induced diploid gynogens progeny in aquatic animals of fishes and crustaceans.Monosex culture of all female shrimp and fishes were selected attribute to all female type offspring which have better size than male and help increase the market size and profitable.This article discusses on the protocol applied to produce gynogens progeny and the successful rate of gynogenesis production in fishes,molluscs and aquatic crustaceans of shrimps in general.Overall most of the UV length applied for irradiated the sperm were around 254-365 nm for(20-40 s),(20-80 s)and(5-8 s)for shrimps,254 nm,30 s for molluscs species and for fishes were around 254 nm for(1.5min)and(2-12 min)time of exposure respectively.For gynogenesis induction,the fertilized eggs were treated with cold shock,heat shock or cytochalasin-B for both shrimp and fishes gynogens technique.Fertilization rate was identified around 4.33%-19.67%in shrimp.Successful hatching rate was identified around 3.0%,14.9%-37.2%of gynogens offspring in shrimp and various percentages of hatching rates were identified from each species of fish gynogens.Overall,there is still low survival rate of gynogens produced using gynogenesis technique and further study should be carried out to improve the gynogens production.The discussed protocols serve as a guide lines for the gynogenesis technique application of all female monosex culture in the future.

Utilization of microwave steam pyrolysis to produce biochar for thermal energy storage

Microwave steam pyrolysis(MSP)is an innovative thermochemical approach to converting biomass into high-quality biochar using steam to improve the dielectric heating of microwave radiation.Biochar shows high fixed carbon and carbon contents at a maximum temperature of 550℃in 10 min.The MSP achieved a heating rate of 112℃/min from 200℃to 400℃to produce biochar effectively.Furthermore,the thermal properties of biochar in microwave heating were investigated in this study to explore its potential as a microwave heat-absorbent material.Microwave is able to perform volumetric and controllable heating to the biochar.Moreover,biochar shows good microwave heat absorbency,storing and transferring heat effectively.The temperature profile of three different sizes of biochar was investigated to examine the efficiency of biochar in heat absorption from microwave radiation.It was found that the powder form of biochar showed a higher heat transfer rate of 40℃/min and a low cooling rate of 7.5℃/min.The presented results are useful for evaluating the application of biochar as a promising medium for heat storage systems.

Vinyl chloride accident unleashes a toxic legacy

A railroad accident on February 3,2023,led to the release and combustion of 115,580 gallons,equivalent to over 437,000 L,of vinyl chloride monomer(VCM)in East Palestine,Ohio[1].This monomer is used in polyvinyl chloride(PVC)production,and its burning produces additional toxins such as hydrochloric acid and lethal phosgene,known as a notorious chemical weapon during World War I[2].Acute exposure to these chemicals causes immediate adverse effects on local ecosystems,including the deaths of wild and farmed animals and pets.

Man-made reactive oxygen species as green disinfectants

The ongoing pandemics boost the demand for chemical disinfectants,including surface disinfectants and hand sanitizers[1].This is largely driven by increasing public health awareness and hygiene standards in public and private settings[2].The global surface disinfectant market size in 2019 was valued at US$3.4 billion and estimated to experience a 6.0%compound annual growth rate,reaching US$5.42 billion in 2027[3].

The environmental threats from lead ammunition

Lead(Pb)is an extremely toxic persistent element,considered a factor in the fall of the Roman Empire 2000 years ago due to its use in plumbing and as a wine sweetener[1].The effects of lead include adverse neurological effects,reproductive impairment,and anaemia[2].One continuing source of lead in the environment is lead ammunition,which presents health risks to consumers of game meat,including humans,predatory and scavenging birds,and other animals.

Amino acid compounds released by the giant freshwater prawn Macrobrachium rosenbergii during ecdysis:a factor attracting cannibalistic behaviour?

Ecdysis is a comm on phe nomenon that happe ns throughout the life phase of the giant freshwater prawn Macrobrachium rosenbergii.It is vital to better understand the correlation between cannibalism and biochemical compound that exists during the moulting process.The objective of the present study was to determine the amino acid profile released by M.rosenbergii during the ecdysis process that promotes cannibalism.To accomplish this,changes in amino acid levels(total amino acid(TAA)and free amino acid(FAA))of tissue muscle,exoskeleton,and sample water of culture medium from the moulting(E-stage)and non-moulting(C-stage)prawns were analysed using highperformanee liquid chromatography(HPLC).Comparison study revealed that among the TAA compounds,proline and sarcosine of tissues from moulting prawn were found at the highest levels.The level of FAA from water that contains moulting prawns(E-stage)was dominated by tryptophan and proline.Significant values obtained in the present study suggested that these amino acid compounds act as a chemical cue to promote cannibalism in M.rosenbergii during ecdysis.The knowledge of compositions and compounds that were released during the moulting process should be helpful for better understanding of the mechanism and chemical cues that play roles on triggering cannibalism,and also for future dietary man ipulati on to improve feeding efficie ncies and feeding man agement,which in directly impacts productivity and profitability.

Is engineered wood China’s way to carbon neutrality?

China emits more than 25%of the world’s carbon dioxide(https://ourworldindata.org/co2-emissions),and in December 2021 the country’s daily carbon trading volume hits a new highest record.Together with the EU and USA,China bears a great responsibility to limit global warming to 2℃,and therefore recently launches a plan to be carbon-neutral be-fore 2060(https://ourworldindata.org/co2-emissions).However,its rapid urbanization challenges this initiative as the boom-ing building and construction industry constitute more than 1/3 of the total energy consumption,which undesirably in-creases carbon emissions(IEA,2019;Duan et al.,2021).Although China has built five new nuclear power stations and closed down more than 1000 coal-fired power plants,it is still highly insufficient to meet the country’s goal to be carbon-neutral(https://climateactiontracker.org/countries/china/).

Plastic crisis underscores need for alternative sustainable-renewable materials

The current global plastic crisis is triggered by several factors including increased costs of petrochemical feedstock and Covid-19 disruption of the transport sector(Yuan et al.,2021).This disruption of world-wide supply chains of polyethylene,polypropylene and other petroleum-based hydrocarbon chemicals has significantly increased shortage and prices of plastics in for example Europe over the last year,hence calling for sustainable alternatives to conventional plastics(WMW,2021,European Plastic Manufacturers sound the Alarm Bell on Supply Chain Disruption,Waste Management World.).This is critical due to extensive use of the non-biodegradable personal protective equipment(PPE)masks in the current pandemic,which might be even worse than the shortage of polyolefins at the moment(Deng et al.,2022).