BIOFILM DEFOULING USING MICROBUBBLES GENERATED BY FLUIDIC OSCILLATIONS

The physical separation offered by membrane filters such as Reverse Osmosis (RO), Microfiltration (UF), Ultrafiltration (UF), and Nanofiltration (NF) has reduced the operating cost of such processes compared to distillation and chemical extraction. The advantages of the membrane such as high selectivity, high capacity, feasibility and cost effectiveness make them very good alternatives in separation industries especially cleaning technologies. Membranes, however, are easily fouled. Since the methods developed to defoul a membrane such as ultrasonic and chemical backflushing are always damaging to the membrane, this study is to explore the potential of microbubbles to restore the membrane to its operational condition. Microbubble clouds generated using fluidic oscillation produce non-coalescent bubbles, smaller and more uniform in size. Fluidic oscillation generated microbubbles are influenced by adjusting flow rate and oscillation frequency in conjunction with the diffuser pore size. The size of the microbubble produced is ranging from 30μm to 500μm at the lowest flow rate of air. The effect for cleaning purposes of microbubble injection with and without fluidic oscillation is explored by examination using Scanning Electron Microscopy (SEM), Total Suspended Solid (TSS) and system operational pressure drop (TMP). The smaller microbubble means higher surface contact area to remove the biofilm on the membrane filter. To further validate the effect of microbubbles on detaching and cleaning, FO generated microbubbles were sparged on biofilm (Chlamydomonas algae and HeLa cells) cultured on microscope slide surface. The detachment rates were compared by observing the density of algae and cells removed from the surface using lux meter and cell counting method. It is found that microbubbles generated using Higher Oscillation frequency of Fluidic Oscillator (HOFO) has a higher detachment and defouling rate. The highest defouling rate recorded for MF filter was 9.53mbar/min using HOFO, followed by 6.22mbar/min of microbubbles generated using Lower Oscillation frequency of Fluidic Oscillator (LOFO). Similar trends were observed in algae and cell detachment, the highest oscillation frequency of 335Hz has the highest detachment rate of 1.775lx/min and 1.7 ́104 cell/ml respectively. For MF systems, microbubbles generated using Higher Oscillation Frequency Oscillator (HOFO), increased the defouling rate by 64%. Similar observation recorded where HOFO increased detachment rate of Chlamydomonas algae and HeLa cells by 42% and 95% respectively

Rapid-Slow Sand Filtration for Groundwater Treatment: Effect of Filtration Velocity and Initial Head Loss

Iron (Fe) and manganese (Mn) are two of many substances that causing harm to human health and various environmental contamination. This study investigates the performance of rapid sand filter as an improvement to the existing commercial filter media. Rapid sand filters were tested using groundwater collected from Kg Budi Kelantan. Groundwater collected were tested using seven velocities ranging from 0.89 to 5.04ml/hr. The concentration of Mn, Fe and turbidity of the treated groundwater were compared. It is found that the highest Mn, Fe and turbidity removal were recorded by using velocity of 4.38ml/hr followed by 2.95ml/hr and 2.4 ml/hr. These three velocities represent more than 95% removal of final treated groundwater, where final Fe, Mn and turbidity ranging from 0.06 mg/L to 0.09 mg/L, 0 to 0.4 mg/L and 0.9 to 3.0 NTU, respectively. A positive trend also recorded where the initial head loss of the sand filter is directly proportional to the flow velocity. This means the filter media was still under a clean condition and no accumulation of sediment deposit occurs. The significance of this study to treat groundwater by removing the iron and manganese especially in rural areas were achieved successfully

Synthesis, characterisation and evaluation on the performance of ferrofluid for microplastic removal from synthetic and actual wastewater

Synthesis of ferrofluid without the addition of stabilizing agents or surfactants is an innovation of new method for microplastic removal. This study focuses on the ability of several types of oils as carriers and how they may improve the removal efficiency of the microplastic. The method is relatively low cost, simple and sustainable. The formation of ferrofluid involved the mixing of oil and iron oxide powder. The experimental work was commenced by adding 2 mm polyethylene terephthalate (PET) microplastics into synthetic ferrofluid. Then, the removal efficiency of microplastics was examined by varying the elements of ferrofluid based on three specific parameters, namely type of oil, volume of oil and dosage of iron oxide to obtain a standard formulation of the optimum results. Overall findings of the study indicated that the optimum formulation for ferrofluid preparation was at a ratio of 1:2.5 (volume of oil: dosage of magnetite) using lubricating oil which has successfully removed 99% of microplastic from water media. Subsequently, the physical and chemical properties of the prepared ferrofluid were also analysed using scanning electron microscope (SEM) and Fourier transform infrared (FTIR) spectroscopy. Performance evaluation of the prepared ferrofluid on actual wastewater (laundry wastewater) revealed that 64% of microplastics were removed after treatment

Polysulfone/Cellulose Acetate Phthalate/Polyvinylpyrrolidone (PSf/CAP/PVP) Blend Membranes: Effect of Evaporation Time on Blend Membrane Characteristics

Recently, researchers proved that the evaporation time during the membrane fabrication process has a significant effect on the characteristics and performance of membranes. In this study, flat sheet asymmetric polysulfone/cellulose acetate phthalate/polyvinylpyrrolidone (PSf/CAP/PVP) blend membranes were fabricated at different evaporation time in the range of 0–20 s to investigate the effect of the evaporation time on characteristics of the blend membranes. The PSf/CAP/PVP blend membranes were characterized in terms of water content, porosity, pure water flux and permeability coefficient. The results showed that an increase of evaporation time from 0 to 20 s has resulted in decreasing of water content and porosity of the PSf/CAP/PVP blend membranes. The permeation water flux of the blend membrane was decreased with the increment of evaporation time. This indicated that an increase of evaporation time would lead to a decrease of the membrane permeability coefficient and hence increased the membrane resistance to permeation of water through the membranes

Palm date meal as a non-traditional ingredient for feeding aquatic animals: A review

Protein ingredients in aquafeed are one of the most important factors responsible for the development and sustainability of aquaculture. Currently, because of high costs and fluctuating production, some animal and plant protein sources are unable to satiate the increasing demand from the fish feed manufacturers. Aquatic animals’ nutritional requirements have been accorded particular focus with less costly feedstuff in aqua feed given extra weightage. There has been increasing attention in recent years on finding methods to recycle the animal and plant by-products for feed preparation. Due to its vital amino acid content as well as high protein composition, palm date meal (PDM) which is a renewable and sustainable resource is expected to be a viable raw material option for replacing protein ingredients (e.g., fish meal and soybean meal) or as a supplement in fish feed. PDM is an agro-industry by-product which left from dates as waste in several countries. This article reviewed the current research including the source, derivatives, and the potential of PDM as a possible alternative to the conventional plant and animal protein sources. Also, the added value of using PDM waste in aquafeed to reduce the feed cost, enhance this e growth rate of fish, improve the health and well-being of fish, and subsequently sustain the aquaculture industry. Therefore, this review paper will illuminate the possibility of PDM as a promising feed source and also the present knowledge and future perspectives about the application of PDM in aquaculture

Rapid-Slow Sand Filtration for Groundwater Treatment: Effect of Filtration Velocity and Initial Head Loss

Iron (Fe) and manganese (Mn) are two of many substances that causing harm to human health and various environmental contamination. This study investigates the performance of rapid sand filter as an improvement to the existing commercial filter media. Rapid sand filters were tested using groundwater collected from Kg Budi Kelantan. Groundwater collected were tested using seven velocities ranging from 0.89 to 5.04ml/hr. The concentration of Mn, Fe and turbidity of the treated groundwater were compared. It is found that the highest Mn, Fe and turbidity removal were recorded by using velocity of 4.38ml/hr followed by 2.95ml/hr and 2.4 ml/hr. These three velocities represent more than 95% removal of final treated groundwater, where final Fe, Mn and turbidity ranging from 0.06 mg/L to 0.09 mg/L, 0 to 0.4 mg/L and 0.9 to 3.0 NTU, respectively. A positive trend also recorded where the initial head loss of the sand filter is directly proportional to the flow velocity. This means the filter media was still under a clean condition and no accumulation of sediment deposit occurs. The significance of this study to treat groundwater by removing the iron and manganese especially in rural areas were achieved successfully

Olive oil by-products in aquafeeds: opportunities and challenges

The increment in world population has led to the increasing demands for fish supply as principal source of animal protein that represents about 17% of animal protein consumption globally. The world aquaculture industry has expanding remarkably but limited source of fishmeal and fish oil which known as important ingredients in fish feed has led to seeking of alternative sources for their replacement in aquafeed formulation. Many potential and cheaper ingredients derived from vegetable oils or agricultural by-products have been investigated to replace fish meal and fish oil which shown promising results in fish productivity and fish health status including olive oil by- products. Varies depending on its type, olive oil composes of antioxidants, healthy type of fats such as MUFA and PUFA, and high in vitamins that provide human health benefits for heart and liver, help in many diseases and reducing the risk of cancer. In agriculture industry, olive and olive oil production processes have resulted to by- products such as olive mill wastewater (OMW), olive leaf and olive pomace. The inclusion of these by-products in animal feeds is the solution for agricultural waste management. The first report of utilization of olive oil by- products in fish feed was documented in 2004 and since then, many researches has been conducted to investigate fish health benefits that showed improvement in fish carcass composition and fish immunity depending on type of by-products used and fish species. Additionally, antioxidant contents in olive oil extract were reported could provide antimicrobial, antifungal and antioxygenic characteristics which potentially improve the fish health. This review discussed the opportunities and challenges in application of olive oil by-products in aquafeed which provides significant prospects in fish growth performance that could boost aquaculture industry development

Coconut Palm: Food, Feed, and Nutraceutical Properties

The price of traditional sources of nutrients used in animal feed rations is increasing steeply in developed countries due to their scarcity, high demand from humans for the same food items, and expensive costs of raw materials. Thus, one of the alternative sources is coconut parts or coconut as a whole fruit. Coconut is known as the ‘tree of abundance’, ‘tree of heaven’, and ‘tree of life’ owing to its numerous uses, becoming a very important tree in tropical areas for its provision of food, employment, and business opportunities to millions of people. Coconut contains a rich profile of macro and micronutrients that vary depending on the parts and how they are used. It is frequently chosen as an alternative source of protein and fiber. Its uses as an antibacterial agent, immunomodulant, and antioxidant further increase its importance. Using coconut oil in ruminant feed helps to minimize methane gas emissions by 18–30%, and to reduce dry matter intake up to 4.2 kg/d. The aquaculture sectors also use coconut palm as an alternative source because it significantly improves the digestion, growth, lipid metabolism, health, and antioxidative responses. However, coconut is not widely used in poultry diets although it has adequate amount of protein and carbohydrate due to anti-nutritional factors such cellulose (13%), galactomannan (61%), and mannan (26%). This review considered the importance and potential of coconut usage as an alternative ingredient in feed and supplements in various livestock sectors as it has plentiful nutrients and functional qualities, simultaneously leading to reduced feed cost and enhanced production