Biogranulation technology for the treatment of anaerobically digested palm oil mill effluent using sequencing batch reactor

Ponding treatment system has been widely used to treat palm oil mill effluent (POME) due to its low operating cost and ease of operation. However, it has some disadvantages such as requirement for a large area, long hydraulic retention time (HRT), and emittance of bad odour. Biogranulation system tested on different types of wastewater offers a solution for the problems. Although this system has been tested for different types of POME, its application in treating anaerobically digested POME has not been previously explored. Therefore, this study was conducted mainly to investigate the feasibility of biogranulation system for treatment of anaerobically digested POME. This study was carried out using a laboratory-scale sequencing batch reactor (SBR) under intermittent anaerobic and aerobic conditions with a working volume of 2 L. Serratia marcescens SA30 (SMSA30) strain was added to the system to treat high concentration of oil and grease (O&G) in wastewater. The system was operated with the variable organic loading rates (OLR) of 0.69 to 9.90 (kg/m3 d), HRT of 4 to 24 h, and superficial air velocity (SAV) of 2 cm/s. After 60 days addition of SMSA30 strain, the flocculent biomass was transformed into biogranules with excellent settleability with improvement in treatment efficiency of the system. Stable biogranules with an average diameter of about 2 mm, sludge volume index (SVI) of 43 mL/g and settling velocity of 81 m/h, were obtained in the biogranular system following 256 days of operation. Upon the biogranules formation, the average removal efficiencies of total chemical oxygen demand (CODT), soluble chemical oxygen demand (CODS), total nitrogen (TN), total phosphorous (TP) and O&G increased from 19 to 52%, 24 to 61%, 51 to 88% and 65 to 84% and 6 to 99.92%, respectively. The results also show that the HRT, OLR and food to microorganism (F/M) ratio influenced the removal efficiency. The removal efficiency of COD, TN, TP and O&G improved with increase in HRT; the percentage of COD and TP removal were slightly increased with the increase of OLR and F/M ratio. By contrast, the removal of TN and O&G was reduced with the increase of the OLR and F/M ratio. The modified mass transfer factor (MMTF) models were used to scrutinise the mechanisms of mass transfer for the biosorption of organic matter and nutrient i.e., CODT and CODS, TN and TP, accumulated onto biogranules. The application of MMTF models verified that resistance of mass transfer is dependent on the film mass transfer for the biosorption of CODT, CODS, TN, and TP. The performance of the biogranular system would increase with increase in global mass transfer factor ([kLa]g) value and thus, provides a new insight in the dynamic response of aerobic digestion to biogranules development. This study demonstrates that the biogranular system, with addition of SMSA30 is feasible for treatment of anaerobically digested POME

Sustainable technology in developed countries: waste municipal management

As more studies were conducted and global events unfold, a greater emphasis is being placed on the importance of preserving the Earth's natural resources and cycles before we face a catastrophic climate crisis. Thus, developed countries are constantly adapting their policies and legislation to promote green development for the sake of sustainable development, which benefits both the environment and the socioeconomic segment. As populations grow and living standards improve, more waste is generated. Appropriate municipal waste management is necessary to avoid harm to the environment, wildlife, and human health. Sustainable municipal solid waste management is even included in the United Nations' (UN) Sustainable Development Goals, which aim to improve the world's environment and economy. The European Union (EU) member states' waste management systems can be considered exemplary. In some countries, landfills have been prohibited, promoting the use of more sustainable technologies such as organic waste incineration, recycling, and composting. However, a divide exists between member countries, with some lagging behind in terms of waste management strategies. Thus, this paper examined the current state of municipal waste in EU member states, followed by a review of the various disposal technologies implemented. The difficulties and environmental concerns that must be overcome are discussed, as are the recommendations and possible future directions

The phytoremediation using water hyacinth and water lettuce : correlation between sugar content, biomass growth rate, and nutrients

Degradation of water quality due to the presence of pollutants in water is an emerging issue in many countries, including Malaysia. Phytoremediation is one of the environmentally friendly, cost-effective conventional technologies that are still used in modern times. However, the selection of plant species is the most important aspect for the application of phytoremediation in wastewater treatment. Nevertheless, there are species of floating aquatic macrophytes that are capable of coping with various pollutants present in wastewater. Among the various floating aquatic macrophyte species, water hyacinth (WH) and water lettuce (WL) have been described as effective phytoremediators in reducing water pollution through bioaccumulation in their body tissues. Hence, WH and WL were chosen in this study as it is easily found, propagated, and cultivated. This paper aims to determine the biosorption capacity of these species in eliminating various pollutants present in wastewater as well as to define the optimum harvesting time for each species. Although these floating aquatic macrophytes are considered the most problematic plants due to their uncontrollable growth in water bodies worldwide, their ability to remove pollutants from wastewater has created a sustainable approach for their use in phytoremediation. In this sense, the use of phytoremediation by implementing the invasive floating aquatic macrophytes can certainly support the sustainable management of wastewater treatment in the future. Based on the results, it was found that WH efficiently removed higher PO4 3-, NO3 - and NO2 - concentrations compared to WL from the wastewater. Both WH and WL showed the same trend of correlation between the growth rate and sugar content, where the sugar content increased when the plants reached the highest growth rate. The maximum nutrient uptake occurred in 14-17 days, proving that nutrient availability is critical for plant growth. This study concludes that the sugar content of WH and WL are increased with the biomass growth rate, and both plants species are competent in eradicating the nutrient pollution in wastewater. On top of that, this study infers that the maximum harvesting period for WH biomass is on day 18, while WL biomass is on day 21; based on the highest sugar content and biomass weight of each species

A two-stage batch system for phosphate removal from wastewater by iron-coated waste mussel shell to assess the optimum adsorbent dosage

High amounts of phosphate discharged in receiving water can lead to eutrophication. Once a water body is enriched with phosphate, it can prompt the growth of plants and cause algal blooms. The water body may also lose its important functions and cause adverse effects on the environment and human health. In this study, removal of phosphate from domestic wastewater treatment plant effluent was elucidated using iron-coated waste mussel shell. The phosphate adsorption by iron-coated waste mussel shell was examined with respect to initial phosphateconcentration (7 mg L–1), solution volume (0.2 L), adsorbent dosage (4–20 g), and contact time (1–5 day). The chemical composition of iron-coated waste mussel shell was analyzed using energy dispersive X-ray fluorescence spectrometer. The measurement of the specific surface area of iron-coated waste mussel shell was performed by multiple-point method according to the Brunauer, Emmett, and Teller theory. Several kinetic models (i.e., pseudo-first order and pseudo-second order) and isotherm models (i.e., Freundlich and Langmuir) were used to describe the adsorption behavior. The optimum removal efficiency of phosphate can reach at 95.7% after 120 h with the amount of iron-coated waste mussel shell used to run the experiment was 20 g and the treated effluent phosphate concentration of 0.3 mg L–1, was verified. Experimental data can be well described by pseudo-second order kinetic model (R2 > 0.99) and Freundlich isotherm model (R2 = 0.93), suggesting that chemisorption and multilayer adsorption occurred. Furthermore, a two-stage batch system was proposed to assess the optimum adsorbent dosage for phosphate removal. The two-stage system has contributed to reduce iron-coated waste mussel shell dosage by 56.94%, as compared to one-stage and thus reduced the operating cost of iron-coated waste mussel shell

Removal of phosphate from synthetic wastewater by using marsh clam (polymesoda expansa) shell as an adsorbent

Phosphate pollution is becoming a serious problem worldwide. It leads to increased algae growth, resulting in eutrophication, which affects the water bodies’ quality, the lives of aquatic organisms, and the daily routines of humankind. Previous research has proven effective chemical precipitation for phosphate removal, but the cost is high and may generate waste material. Thus, this study proposed the marsh clam (Polymesoda expansa) shell as an absorbent due to its abundant availability, low cost, and high absorption capacity of phosphorus. This study was conducted to investigate the removal efficiency of phosphate using raw marsh clamshells. In this study, the concentration of aqueous solution using KH2PO4 was fixed to 10 mg/L of PO4 3− as the initial concentration. The 2 g of mass absorbent (0.075mm, 0.15mm, 0.30 mm, 0.60 mm, 1.18 mm, 2.36 mm) mixed with 100mL of KH2PO4 solution in the conical flask in a certain time interval. The orbital shaker was used for mixing the KH2PO4 solution with the adsorbent. Moreover, HACH DR 6000 Spectrophotometer is then used to determine phosphate concentration for initial and final results. The results were verified using kinetic and isotherm models, where kinetic models used Pseudo First Order (PFO) and Pseudo Second Order (PSO). The isotherm model used the Freundlich and Langmuir models. The optimum performance of the batch experiment showed by the PSO model had the highest correlation coefficient (R2 = 0.9965) and the lowest Fe value of 0.086. This study showed that marsh clamshells could remove PO4 3− effectively for 1.18–2.36 mm size with the highest removal efficiency of 73%. The removal of phosphate from domestic wastewater can be an alternative wastewater treatment in tertiary treatment in the field of the wastewater treatment plant

Phosphate removal from wastewater in batch system using waste mussel shell

High input of phosphate (PO43–) in rivers can lead to eutrophication, which jeopardizes aquatic life and human health. In this study, PO43– was removed from synthetic solution and domestic wastewater treatment plant effluent (DWTPE) by waste mussel shell (WMS). The PO4 3– adsorption by WMS was examined for the initial PO4 3– concentration (7 mg L-1), solution volume (0.2 L), adsorbent dosage (4, 8, 12, 16, and 20 g), and contact time (1-6 d). The batch experiment's optimum performance could reach approximately 75.1% for the removal of PO4 3– from synthetic solution and approximately 66.2% for the removal of PO43– from DWTPE after a contact time of 5 d. This work suggests that the WMS can remove PO43 from both synthetic solution and DWTPE. Future works are necessary to increase WMS's capacity to adsorb PO4 3– from waters, either by physical or chemical modification

Interpretation of isotherm models for adsorption of ammonium onto granular activated carbon

High amounts of ammonium (NH4+) discharged in receiving water can lead to eutrophication. The adsorption of NH4+ from synthetic solution onto granular activated carbon (GAC) was scrutinized with respect to initial solute concentration (10 mg L-1 ), solution volume (0.2 L), adsorbent dosage (4 – 20 g), and contact time. Experimental data can be well described by the pseudo-second-order kinetic model (R2 > 0.994) and Freundlich isotherm model (R2 = 0.936), suggesting that chemisorption and multilayer adsorption occurred. Furthermore, this study explored the feasibility of using the Freundlich isotherm model to estimate the removal efficiency or required amount of adsorbent. The result findings indicated that GAC has a good potential to adsorb NH4+ from water and thus giving new insights into environmental engineering practices

Influence of Microstructural Effect on Microvickers Hardness Properties of SiO2-Na2O-CaO (SNC) Waste Based Glass-ceramic

There are a lot of waste materials consist of silicate based such as coal combustion ash, slag from steel production, fly ash, mud, as well as glass cullet or mixtures to produce glass-ceramics. This research work using clam shell (CS) ash and soda-lime-silica (SLS) waste glass powder for fabricating novel SiO2-Na2O-CaO (SNC) glass-ceramic. The samples were composed of SLS (50%), Na2CO3 (30%), and CS (20%) in weight percentage via conventional melt-quenching technique and solid-state sintering technique. The samples were investigated via X-Ray Diffractometer (XRD), Field emission microscope (FESEM), and microvickers hardness tester. The samples were sintered at 550-950 °C to investigate the influence of microstructural effect on microvickers hardness properties at applied force 0.5 and 1.0 kgf. The optimal Vickers hardness properties at sintering temperature 850 °C due to high crystallization of SiO2 phase from the residual glass and CaO content enhanced the viscosity flow, high compactness of particles arrangement and densification of sample

Influence of Microstructural Effect on Microvickers Hardness Propertiesof SiO2-Na2O-CaO (SNC) Waste Based Glass-ceramic

There are a lot of waste materials consist of silicate based such as coal combustion ash, slag from steel production, fly ash, mud, as well as glass cullet or mixtures to produce glass-ceramics. This research work using clam shell (CS) ash and soda-lime-silica (SLS) waste glass powder for fabricating novel SiO2-Na2O-CaO (SNC) glass-ceramic. The samples were composed of SLS (50%), Na2CO3 (30%), and CS (20%) in weight percentage via conventional melt-quenching technique and solid-state sintering technique. The samples were investigated via X-Ray Diffractometer (XRD), Field emission microscope (FESEM), and microvickers hardness tester. The samples were sintered at 550-950 °C to investigate the influence of microstructural effect on microvickers hardness properties at applied force 0.5 and 1.0 kgf. The optimal Vickers hardness properties at sintering temperature 850 °C due to high crystallization of SiO2 phase from the residual glass and CaO content enhanced the viscosity flow, high compactness of particles arrangement and densification of sample

Structural behaviour of a single tendon end block

There are many proprietry design for end blocks with cable of multiple tendons available in the market. However, in this study tests have been carried out on end block with single tendon specifically design for laboratory work. This study investigate the effect of different types of bursting reinforcement, number of bearing plate and size of end block for a single tendon cable. A total number of 18 end blocks have been tested until failure using a compression testing machine. Failure load were than compared with those obtained from design using BS 8110: 1997 and CIRIA guide 1 (1976). Test results show that spiral bursting reinforcement failed with higher failure load than orthogonal bursting reinforcement. Is has been noticed that end block using two bearing plate separately can accommodate a higher failure load compared with using only a single bearing plate. The overall failure loads for all the specimens are closer to that design by BS 8110: 1997 and thus it can be concluded that it is a more conservative design than CIRIA guide 1 (1976)