The fast pyrolysis of waste lignin derived from biobutanol production process was performed to determine the optimal pyrolysis conditions and pyrolysis product properties. Four types of pyrolysis reactors, e.g.: micro-scale pyrolyzer-gas chromatography/mass spectrometry, lab and bench scale fixed bed (FB) reactors, and bench scale rotary kiln (RK) reactor, were employed to compare the pyrolysis reaction conditions and product properties obtained from different reactors. The yields of char, oil, and gas obtained from lab scale and bench scale reactor were almost similar compared to FB reactor. RK reactor produced desirable bio-oil with much reduced yield of poly aromatic hydrocarbons (cancer precursor) due to its higher cracking reaction efficiency. In addition, char agglomeration and foaming of lignin pyrolysis were greatly restricted by using RK reactor compared to the FB reactor.
A large amount of wastewater is typically discharged into water bodies and has extremely harmful effects to aquatic environments. The removal of heavy metals from water bodies is necessary for the safe consumption of water and human activities. The demand for seafood has considerably increased, and millions of tons of crustacean waste are discarded every year. These waste products are rich in a natural biopolymer known as chitin. The deacetylated form of chitin, chitosan, has attracted attention as an adsorbent. It is a biocompatible and biodegradable polymer that can be modified and converted to various derivatives. This review paper focuses on relevant literature on strategies for chemically modifying the biopolymer and its use in the removal of heavy metals from water and wastewater. The different aspects of chitosan-based derivatives and their preparation and application are elucidated. A list of chitosan-based composites, along with their adsorptivity and experimental conditions, are compiled.
The recent implication of circular economy in Australia spurred the demand for waste material utilization for value-added product generations on a commercial scale. Therefore, this experimental study emphasized on agricultural waste biomass, rice husk (RH) as potential feedstock to produce valuable products. Rice husk biochar (RB) was obtained at temperature: 180 °C, pressure: 70 bar, reaction time: 20 min with water via hydrothermal carbonization (HTC), and the obtained biochar yield was 57.9%. Enhancement of zeta potential value from - 30.1 to - 10.6 mV in RB presented the higher suspension stability, and improvement of surface area and porosity in RB demonstrated the wastewater adsorption capacity. Along with that, an increase of crystallinity in RB, 60.5%, also indicates the enhancement of the catalytic performance of the material significantly more favorable to improve the adsorption efficiency of transitional compounds. In contrast, an increase of the atomic O/C ratio in RB, 0.51 delineated high breakdown of the cellulosic component, which is favorable for biofuel purpose. 13.98% SiO2 reduction in RB confirmed ash content minimization and better quality of fuel properties. Therefore, the rice husk biochar through HTC can be considered a suitable material for further application to treat wastewater and generate bioenergy.
Alkali activated concretes have emerged as a prospective alternative to conventional concrete wherein diverse waste materials have been converted as valuable spin-offs. This paper presents a wide experimental study on the sustainability of employing waste sawdust as a fine/coarse aggregate replacement incorporating fly ash (FA) and granulated blast furnace slag (GBFS) to make high-performance cement-free lightweight concretes. Waste sawdust was replaced with aggregate at 0, 25, 50, 75, and 100 vol% incorporating alkali binder, including 70% FA and 30% GBFS. The blend was activated using a low sodium hydroxide concentration (2 M). The acoustic, thermal, and predicted engineering properties of concretes were evaluated, and the life cycle of various mixtures were calculated to investigate the sustainability of concrete. Besides this, by using the available experimental test database, an optimized Artificial Neural Network (ANN) was developed to estimate the mechanical properties of the designed alkali-activated mortar mixes depending on each sawdust volume percentage. Based on the findings, it was found that the sound absorption and reduction in thermal conductivity were enhanced with increasing sawdust contents. The compressive strengths of the specimens were found to be influenced by the sawdust content and the strength dropped from 65 to 48 MPa with the corresponding increase in the sawdust levels from 0% up to 100%. The results also showed that the emissions of carbon dioxide, energy utilization, and outlay tended to drop with an increase in the amount of sawdust and show more the lightweight concrete to be more sustainable for construction applications.
Utilizing agro-waste material such as rice husk (RH) and coco peat (CP) reinforced with thermoplastic resin to produce low-cost green composites is a fascinating discovery. In this study, the effectiveness of these blended biocomposites was evaluated for their physical, mechanical, and thermal properties. Initially, the samples were fabricated by using a combination of melt blend internal mixer and injection molding techniques. Increasing in RH content increased the coupons density. However, it reduced the water vapor kinetics sorption of the biocomposite. Moisture absorption studies disclosed that water uptake was significantly increased with the increase of coco peat (CP) filler. It showed that the mechanical properties, including tensile modulus, flexural modulus, and impact strength of the 15% RH-5% CP reinforced acrylonitrile-butadiene-styrene (ABS), gave the highest value. Results also revealed that all RH/CP filled composites exhibited a brittle fracture manner. Observation on the tensile morphology surfaces by using a scanning electron microscope (SEM) affirmed the above finding to be satisfactory. Therefore, it can be concluded that blend-agriculture waste reinforced ABS biocomposite can be exploited as a biodegradable material for short life engineering application where good mechanical and thermal properties are paramount.
This article presents experimental data on oil palm biomass (oil palm leaves, oil palm trunk and empty fruit bunch) handsheet production characterization by biodelignification treatment using Bacillus cereus extracted from termite gut (Coptotermus curvignathus). It associates the lignocellulose chemical composition obtained via technical association pulp and paper industry TAPPI T 222 om-02 testing on lignin content reduction determination, holocellulose and hemicellulose content determination (Kurscher-Hoffner method). Several data obtained for handsheet characterization presents brightness, opacity, contrast ratio, din transparency, thickness, bursting and tearing indexes are collected. Handsheet surface morphology was also observed on ratio of gaps differences between fiber bonding conducted using scanning electron microscope (SEM) and ImageJ software. The raw data findings supplement chemical composition analysis for both untreated and treated substrates on handsheet quality performance check as presented in the research article "Bio-Mechanical Pulping of Bacteria Pre-Treatment on Oil Palm Biomass for Handsheet Production" [1]. For understanding correlations into the difference among lignocellulose content composition which affect the handsheet formation and mechanical strength refer to article from this research [1]. This dataset is made publicly available for optimizing alternative waste material reuse in the pulp and paper industrial section.
This paper attempts to integrate both a forward and reverse supply chain to design a closed-loop supply chain network (CLSC). The problem in the design of a CLSC network is uncertainty in demand, return products and the quality of return products. Scenario analyses are generated to overcome this uncertainty. In contrast to the existing supply chain network design models, a new application of a CLSC network was studied in this paper to reduce waste. A multi-product, multi-tier mixed integer linear model is developed for a CLSC network design. The main objective is to maximize profit and provide waste management decision support in order to minimize pollution. The result shows applicability of the model in the tire industry. The model determines the number and the locations of facilities and the material flows between these facilities.
Rubber seed as a waste product from rubber plantations contains nutritive values that can be harnessed
as food for human, feed for animals or biofuel for energy. Proximate analysis showed moisture content of
3.99%, protein content of 17.41 g/100g, fat content of 68.53 ± 0.04 g/100g and ash content of 3.08 ± 0.01
g/100g. Amino acid in rubber seed is high in Glutamic acid (16.13%) and low in Cysteine (0.78%). Despite its potential as a source of protein, fresh rubber seeds contain a toxic factor, cyanogenetic glucoside (186 mg/kg). FAME analysis indicated that rubber seed oil is high in oleic, linoleic and linolenic acid. The fuel potential of rubber seed (585.41 kJ/kg) is in reasonable agreement with ASTM.
Sludge is an unavoidable product of wastewater treatment that creates problems of disposal. Increasingly, strict environmental control regulations have resulted in limitations on sludge disposal options.Disposal by incineration has been found to be a good option. In this research, application of domestic waste sludge powder (DWSP) was used as cement replacement in concrete mix. This study utilised replacement of 3 %, 5 %, 7 %, 10 % and 15 % by weight of OPC with water binder (w/b) ratio of 0.60, 0.55 and 0.40 for Grade 30, Grade 40 and Grade 50 respectively. The performance of DWSP concrete in terms of its compressive strength, water absorption, water permeability and Rapid Chloride Ion penetration were investigated. All values of compressive strength for DWSP concrete were lower compared to the OPC control, and the strength decreased as the percentage of replacement with DWSP increased for Grade 30 and Grade 50, except for Grade 40 at replacement of 7 %. Meanwhile, water absorption and water permeability for the DWSP concrete increased as the replacement increased. Overall, with further research in producing quality DWSP, the potential of using this waste as a cement replacement material is very promising.
In accordance upon conservation efforts, this research emphasizes on prevention of
environmental pollution and considers the elements of sustainable of infrastructure
construction materials, which is interlocking pavement block. The development of this
innovative product apply the concept of 3Rs and waste to wealth by using the
agricultural waste product, coconut shell, where widely available with very minimum
cost worldwide especially in tropical country such as India, Indonesia, Philippines,
Thailand and Malaysia. The main objective of this research is to produce an
environmental friendly product with a good quality, low cost and lightweight known as
Green Interlocking Pavement (GIP Block). The chemical composition of coconut shell
ash and ordinary Portland cement being identified and compared to know whether it
is able to react as a good binder in the mixture or not. The quality of GIP Block
considered is compressive strength, water absorption and bulk density. All the blocks
were curing in seven and 28 days before implementing the entire test. The existing
interlocking pavement used as bench mark and GIP Block 0% of proportion of coconut
shell ash used as control variables. The specimen of the interlocking pavement
prepared in this research is 10%, 20% and 30% proportion of coconut shell ash to
partially replace the quantity of cement. The ratio of the interlocking pavement apply
in this research is 1:2 which stand for one part cement and two part of sand. The
findings withdrawn from this research are: first, the chemical characteristic of the
coconut shell ash and cement. Second, the value of bulk density slightly reduces as the
percentage of coconut shell ash increases. Third, the additional of coconut shell ash to
partially replace the quantity of cement in the product reduce the compressive
strength and increase the percentage of water absorption.
Guava seeds are produced as a waste product by the guava processing industry. Their high carbohydrate contents may suit the carbohydrate needs of the feed sector but their high dietary fiber content limits their feed value. The feed values of fruit seeds can be improved through germination, which involves the mobilization of nutrients through seed enzymes and alters the seed carbohydrate composition. The changes of selected carbohydrates in guava (Psidium guajava L.) seeds brought by germination to those in red bean (Vigna angularis) and winter wheat (Triticum aestivum L.) were compared. The contents of soluble carbohydrates, digestible starch, resistant starch and cellulose in the seeds were determined. The radial diffusion method was used to detect carbohydrate-degrading enzymes in the seed extracts. Guava seeds were rich in cellulose (402.2 mg/g), which decreased progressively during germination, probably through the action of cellulase. Winter wheat contained the highest starch content (412.2 mg/g) and also distinct quantities of α-amylase and cellulase. The starch contents of all the seeds decreased, but the soluble carbohydrate contents in red beans and guava seeds increased significantly by the end of germination, suggesting the transient oversupply of reserve metabolites. The content of hydrolyzed polysaccharides increased in the germinated seeds with detectable amounts of cellulose-degrading enzymes present, indicating improved value as feed. Further research is warranted to explore the potential of guava seeds as a source of low-cost animal feed supplements.
The increase in the price of commercial succinic acid has necessitated the need for its
synthesis from waste materials such as glycerol. Glycerol residue is a waste product of
Oleochemical production which is cheaply available and a very good source of carbon.
The use of immobilized cells can further reduce the overall cost of the production process.
This study primarily aims to produce succinic acid from glycerol residue through the use
of immobilized Escherichia coli in a batch fermentation process. The parameters which
affect bacterial fermentation process such as the mass substrate, temperature, inoculum
size and duration of fermentation were screened using One-Factor-At-a-Time (OFAT)
method. The result of the screening process shows that a substrate (glycerol) concentration
of 30 g, inoculum size 20% v/v, and time 4 h produced the maximum succinic acid
concentration of 117.99 g/L. The immobilized cells were found to be stable as well as
retain their fermentative ability up to the 6th cycle of recycling, thereby presenting as an
advantage over the free cell system. Therefore, conclude that using immobilized cells can
contribute immensely to the cost-effective production of succinic acid from glycerol
residue.
The capsicum seed core and cabbage outer leaves are common wastes generated in the vegetable processing industry. We explored the in vitro health-promoting activity of these waste products for valorization. Freeze-dried and pulverized cabbage wastes had a high bile acid binding capacity and the capsicum wastes inhibited glucose dialysis more effectively. Methanolic extracts prepared with conventional solvent extraction and ultrasound-assisted extraction were analyzed to determine their 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, in vitro α-amylase inhibitory, in vitro lipase inhibitory, and prebiotic activity. Crude extracts of cabbage and capsicum wastes were screened using GC-MS analysis. The cabbage waste extracts showed high antioxidant activities but did not inhibit α-amylase. The capsicum waste extracts inhibited both lipase and α-amylase activities and supported the growth of the probiotic bacterium, Lactobacilli brevis. Volatile compounds of the vegetables consisted mainly of phenols and fatty acid esters. In all assays except the α-amylase inhibition assay, the extracts prepared with ultrasound-assisted solvent extraction showed higher activity than those prepared using the conventional method. The capsicum seed core and cabbage outer leaves are potential sources of phytochemicals and antioxidant fibers. Capsicum waste extract supported probiotic bacterial growth without a lag phase. These waste products may be processed into high-value functional ingredients.
This paper presents the results for surface water quality parameters measured in the Setiu Wetland, on the east coast of Malaysia, which feeds into the southern part of the South China Sea. There are no previous studies dealing with the seasonal and spatial variation of water quality in this area, despite numerous anthropogenic inputs into this ecologically and economically important wetland. The parameters measured were salinity, temperature, dissolved oxygen (DO), pH, biological oxygen demand (BOD) and total suspended solids (TSS). These parameters were sampled monthly from October 2009 to September 2010, during both the wet and dry seasons, at ten sampling stations distributed throughout the area. The physical water quality parameters were measured in situ whilst TSS and BOD were determined using the standard methods. A deterioration of water quality in the Setiu Wetland was observed in areas near agriculture and aquaculture activities. This was expected to be as a result of the use of fertilisers, waste from fish farm food and the waste products of aquaculture. The parameters measured showed lower mean values of surface salinity, temperature, DO, pH and TSS during the wet season relative to the dry season. In contrast, the concentration of BOD was high during the wet season and lowest in the dry season. Results obtained from this study clearly showed the surface physical water quality for the Setiu Wetland was highly influenced by anthropogenic activities and seasonal variation. Therefore, both factors must be considered to move towards proper management of this wetland.
In this article, the utilization of fungi for the degradation of xenobiotic organic compounds (XOCs) from different wastewater and aqueous solutions has been reviewed. The myco-remediation (myco-enzymes, myco-degradation, and myco-sorption) process is widely used to remove XOCs, which are not easily biodegradable. The removal of XOCs from textile wastewaters through chemical and physical processes has been addressed by many researchers. Currently, the application of oxidative enzymes [manganese peroxidase (MnP), lignin peroxidase (LiP), and laccase] and myco-adsorption is becoming more common for the removal of XOCs from wastewater. Although the advanced oxidation process (AOPs) is a preferred technology for removing XOCs, its use is restricted due to its relatively high cost, which led to research studies on non-traditional and low-cost technology. The current review aimed to organize the scattered available information on the potential of myco-remediation for XOC removal. Moreover, the utilization of agricultural wastes as a production substrate for oxidative enzymes has been reported by many authors. Agricultural waste materials are highly inducible for oxidative enzyme production by fungi and are cost-effective in comparison to commercial substances. It is evident from the literature survey of 80 recently published papers that myco-enzymes have demonstrated outstanding XOC removal capabilities. Fungal laccase enzyme is the first step to degrade the lignin and then to get the carbon source form the cellulose by cellulose enzyme.
Cement industries globally produced about 2.282 billion ton/year and 25 billion tons of concrete are produced yearly
all over the world, necessary measures are to be taken to reduce energy use along with the prevention of environmental
degradation, depletion of the limited resources and contribute 7% to global warming effects due to the release of carbon
dioxide to the atmosphere. Cement additives quality improver polymer (CAQIP) was developed from synthesized polymer,
waste materials derived from petro-chemical and palm oil waste for production of sustainable cement. Industrial scale
trial in a local cement plants by dosing 0.009%-0.690% CAQIP significant improved productivity, 8.3-27.5% efficiency in
saving, 24.73-86.36% clinkering energy and 7.7-21.57% grinding energy in the production of Ordinary Portland Cement
and sustainable cement. Strength quality improved 7.31-34.8% (2 day) and 3.85-57.58% (28 day). Carbon dioxide and
others toxic gases emission was reduced 21.90-90.0% by replacing clinker with waste material such as fly ash (25-
35%), out-spec clinker (50-100%) and limestone waste (5-25%). The developed CAQIP significant improved productivity,
quality strength, reduced CO2
emission, grinding & clinkering energy and enhanced production of sustainable cement
and concrete in Malaysia.
Sweatings, the exudates that leach out from fermenting fruits during rambutan fruit fermentation are considered as
a waste by-product and are allowed to be drained off. This could lead to a pollution problem. Besides, it is a waste if
the sweatings are possible to be transformed into food products and ingredients. However, prior transformation, the
fundamental knowledge of the sweatings should be understood. Hence, the main aim of this study was to investigate
the physicochemical properties of sweatings as affected by fermentation time and turning intervals during natural
fermentation of rambutan fruits. In this study, peeled rambutan fruit was fermented for 8 days and turned. Different
batches of the fruits were turned every 24, 48 or 72 h and sweatings from the process were collected and analyzed.
The results showed that fermentation time significantly reduced (p<0.05) the yield, pH and sucrose content of the
sweatings by 79-84%, 32-33%, 76.5-80.8%, respectively. Fermentation time also significantly increased (p<0.05) the
titratable acidity, total soluble solids, fructose, glucose, total sugar, citric acid, lactic acid, acetic acid and ascorbic
acid contents of the sweatings by 5.6-6.0, 1.5-1.6, 2.4-2.6, 2.1-2.5, 1.0-1.1, 5.7-6.5, 2.4-2.6, 2.1-2.5 and 2.6-2.8 folds,
respectively. However, turning intervals did not significantly affect (p>0.05) the physicochemical properties of the
sweatings. High concentrations of sugars and organic acids allow the sweatings to have a balance of sweet and sour
taste and they are suitable to be used in the production of syrup, soft drinks, jam, jelly, marmalade and vinegar.
This study investigates the engineering performance and CO₂ footprint of mortar mixers by replacing Portland cement with 10%, 20%, 40% and 60% fly ash, a common industrial waste material. Samples of self-compacting mortar (SCM) were prepared with four different water/binder ratios and varying dosages of superplasticizer to give three ranges of workability, i.e., normal, high and self-compacting mortar mix. The engineering performance was assessed in term of compressive strength after designated curing periods for all mixes. CO₂ footprint was the environmental impact indicator of each production stage. The optimum mix obtained was at 10% replacement rate for all mixes. Total production emission reduced by 56% when the fly ash replacement rate increased from 0% to 60% (maximum). This is translated to a reduction of 80% in eco-points (assuming that the energy consumption rate of production with 0% fly ash is at 100%). Such re-utilization is encouraged since it is able to reduce possible soil toxicity due to sulfur leaching by 5% to 27% and landfill area by 15% to 91% on average.
Several technologies are being applied for treatment of palm oil mill wastes. Among them, the biological treatments (vermicomposting) have widely been recognized as one of the most efficient and eco-friendly methods for converting organic waste materials into valuable products. The present study focuses on vermicomposting of acidic palm oil mill effluent (POME) mixed with the palm pressed fibre (PPF) which are found difficult to decompose in the environment. The industrial waste (POME) was vermicomposted using Lumbricus rubellus under laboratory conditions for a period of 45 days. A significant improvement in nitrogen, phosphorus, and potassium content was monitored during vermicomposting process. In addition, the decline in C:N ratio of vermicompost (up to 17.20 ± 0.60) reflects the degree of stabilization of POME-PPF mixture. Different percentages of the vermicompost extract obtained from POME-PPF mixture were also examined for the germination of mung bean (Vigna radiata) seed. The results showed that 75% vermicompost extract demonstrated better performance for the seed germination. On the basis of significant findings, POME-PPF mixture can be successfully used as a feeding material for the earthworms, while on the other hand, it can also be used as a cost-effective fertilizer for the germination and the proper growth of mung bean.
This paper presents the experimental results of an on-going research project on geopolymer lightweight concrete using two locally available waste materials--low calcium fly ash (FA) and oil palm shell (OPS)--as the binder and lightweight coarse aggregate, respectively. OPS was pretreated with three different alkaline solutions of sodium hydroxide (NaOH), potassium hydroxide, and sodium silicate as well as polyvinyl alcohol (PVA) for 30 days; afterwards, oil palm shell geopolymer lightweight concrete (OPSGPC) was cast by using both pretreated and untreated OPSs. The effect of these solutions on the water absorption of OPS, and the development of compressive strength in different curing conditions of OPSGPC produced by pretreated OPS were investigated; subsequently the influence of NaOH concentration, alkaline solution to FA ratio (A/FA), and different curing regimes on the compressive strength and density of OPSGPC produced by untreated OPS was inspected. The 24-hour water absorption value for OPS pretreated with 20% and 50% PVA solution was about 4% compared to 23% for untreated OPS. OPSGPC produced from OPS treated with 50% PVA solution produced the highest compressive strength of about 30 MPa in ambient cured condition. The pretreatment with alkaline solution did not have a significant positive effect on the water absorption of OPS aggregate and the compressive strength of OPSGPC. The result revealed that a maximum compressive strength of 32 MPa could be obtained at a temperature of 65°C and curing period of 4 days. This investigation also found that an A/FA ratio of 0.45 has the optimum amount of alkaline liquid and it resulted in the highest level of compressive strength.