Drilling fluids: presence of hazardous BTEXs and crystalline silica

In the oil and gas industry occupational health risks due to drilling fluids is severe. Mixing room, shale shaker room and drill floor are sites where workers are highly exposed to air pollutants, hazardous dust and even substances generated via drilling fluids associated activities. Barite, calcium carbonate and linear paraffin or olef in-based oil are three types of chemical that are greatly used in huge quantities to prepare drilling fluids. These drilling fluids contain hazardous substances and pose health risks. Due to the occupational health risk, Occupational Safety and Health Administration OSHA Europe and USA have issued guidelines for the permissible exposure limit (PEL) to be at 5 mg/m3 for barium sulphate, 10 mg/m3 for calcium carbonate, 0.05 mg/m3 for crystalline silica and 0.05 mg/m3 for oil mists. Therefore, this study identified the presence of benzene, toluene, ethylbenzene and xylene (BTEX) ionic mists and crystalline silica in the drilling fluids. The grain size distribution of additives used in the drilling fluids was also determined. The results showed the presence of BTEX and crystalline silica based on random sampling. Therefore, the existing control measures are necessary to reduce the occupational health risks. As a control measure, Artificial Intelligence (AI) and Internet of Things (IoT) are necessary to be introduced for the automation of drilling fluids associated activities

Treatment of wastewater using seaweed: A review

Inadequately treated or untreated wastewater greatly contribute to the release of unwanted toxic contaminants into water bodies. Some of these contaminants are persistent and bioaccumulative, becoming a great concern as they are released into the environment. Despite the abundance of wastewater treatment technologies, the adsorption method overall has proven to be an excellent way to treat wastewater from multiple industry sources. Because of its significant benefits, i.e., easy availability, handling, and higher efficiency with a low cost relative to other treatments, adsorption is opted as the best method to be used. However, biosorption using naturally found seaweeds has been proven to have promising results in removing pollutants, such as dyes from textile, paper, and the printing industry, nitrogen, and phosphorous and phenolic compounds, as well as heavy metals from various sources. Due to its ecofriendly nature together with the availability and inexpensiveness of raw materials, biosorption via seaweed has become an alternative to the existing technologies in removing these pollutants from wastewater effectively. In this article, the use of low-cost adsorbent (seaweed) for the removal of pollutants from wastewater has been reviewed. An extensive table summarises the applicability of seaweed in treating wastewater. Literature reported that the majority of research used simulated wastewater and minor attention has been given to biosorption using seaweed in the treatment of real wastewater

Improving the flow of petroleum products in pipelines using natural additives and powders

Liquids transportation through pipelines is considered one of the most power consuming sectors in the industry due to the turbulent mode these liquids are transported within. Skin friction formed by turbulent flow in pipe becomes the main aspect for researchers to explore the field of fluid mechanics. Frictional drag formed in pipelines transporting liquid can be reduced spectacularly by adding minute amounts of drag reducing agents. Drag reduction (DR) is a phenomenon where eddies changes its structure to interact with added material in transporting system for pumping power saving. During the past few decades, artificial additives were used to solve the problem. Most of these additives are not environmentally friendly with high level of toxicity. Therefore, in this present work two novel and environmentally friendly drag reducing agents were introduced. This thesis outlines the performance of natural additives and powders as drag reducing agent in transporting water and diesel via pipelines. The natural additives extracted from the leaves of Hibiscus rosa-sinensis (an agricultural waste) and red gypsum (waste from titanium dioxide manufacturing industry) are the two new drag reducers introduced. The extracted water soluble mucilage then converted to be oil soluble through adapted phase solubility inversion method. The objectives of this research is to analyze the effect of selected investigated materials based on solution concentration, fluid’s Reynolds number, pipe diameter and length of testing section. In order to achieve the objectives of this study, an experimental rig consists of three galvanized pipes of different diameters 0.0381m, 0.0254m and 0.0127m each 2m in length was built as closed loop liquid circulation system. The drag reduction ability of the water soluble mucilage was tested successfully with a maximum DR of 39% achieved in 0.0381m ID and 1.5m length pipe. The drag reduction ability of the oil soluble mucilage gives maximum DR of 47% achieved in 0.0381m ID and 1.5m length pipe. While gypsum powder reduces drag around 26% and 60% in water and diesel solutions respectively achieved in 0.0381m ID and 1.5m length pipe. The statistical drag reduction correlation was modeled with experimental data using STATISTICA software. As a conclusion, new environmentally friendly drag reducing agents were introduced to the field as an alternative to existing commercial additives and its effectiveness in improving the flow was proven experimentally

Formulation of multipurpose grease from titanium dioxide manufacturing waste (red gypsum)

This study describes the formulation of multipurpose grease using red gypsum from titanium dioxide manufacturing wastes. Greases produced with different amount of fume silica (FS) and red gypsum in its compositions. The effect of red gypsum’s and fumed silica’s concentrations on the formulated greases has been studied. The grease mixture is formulated using silicone oil as base oil, fumed silica and red gypsum as thickener, molybdenum disulphide as additive and iron octoate as anti-oxidant agent. Amount of fumed silica involves 2-20% wt (2% wt, 7% wt, 16% wt and 20% wt). All the fume silica proportions covered (70% gypsum, 30% FS), (60% gypsum, 40% FS) and (50% gypsum, 50% FS). The testing (penetration test, type of thickener, dropping point test, and amount of oil separated) have been done on the formulated greases to determine the properties. It was discovered that formulated grease has no dropping point until 260 o C which proves that the greases has stable structure at higher temperature. All the formulated greases proved to be composed of non-melt thickener type. As the amount of fumed silica and red gypsum increase oil separation decreases and the consistency of the greases increases. The penetration also significantly decreases as fumed silica addition increases. This is due to the larger strength and small size of fumed silica. The larger strength of fumed silica was thought to be due to the structure being knit together by means of primary valence bonds. It can be concluded that the formulated grease is multi purpose grease. Higher the amount of fumed silica and gypsum (thickener), better the grease’s quality. Therefore, the formulated greases has high potential to be used in wide range of industries such as the cars, ships, aircrafts and most of the industries that deals with heavy duty equipments

Enzyme production using organic by-products as substrate in solid state fermentation / Nithiya Arumugam

Brewery spent grain (BSG) which was used as the main organic material in this research is the by-product of brewing industries. Every 100 liter of beer generates 20kg of BSG. A Malaysian brewery (Carlsberg (M) Sdn. Bhd) alone generates 31,000 tonnes of BSG yearly. Almost all the BSG are being dumped into landfills, since there is no proper and separate guideline for industrial organic waste management in Malaysia. BSG materials are rich in nutrients and high in fermentable sugar as well as lignin, cellulose and hemicellulose. Dumping this high nutritional substrate into the landfills could contribute to adverse environmental impacts, especially greenhouse gas emission and global warming in long term. It is also can be said useful resourced are being wasted. In order to avoid environmental impacts and resources wastage, BSG can be exploited as a raw material in solid state fermentation (SSF), to produce enzymes with the help of filamentous fungi. The objective of this study is to investigate the potential utilization of BSG in producing enzymes and to identify the fungi that yield higher enzyme activity at different fermentation period and incubation temperature. Chemicals at different concentrations were used in this study to identify the effect of it in inducing the enzyme activity. Five types of filamentous fungi (Aspergillus niger, Fusarium sp., Penicillium chrysogenum, Schizophyllum commune and Trichoderma sp.) were used to determine the production of five types of enzymes including laccase, lignin peroxidase, xylanase, cellulase and amylase. Among the enzymes tested, laccase showed highest activity followed by lignin peroxidase, xylanase, cellulase and amylase in all the experiments conducted. A comparative study between BSG, spent mushroom compost (SMC) and sugarcane bagasse (SCB)was conducted to compare the ability of these substrates to produce higher enzyme activity at similar condition. Results showed BSG exhibited higher enzyme activity compared to other substrates. Enzyme activity in BSG fermented with different types of filamentous fungi was tested at different incubation period (day 1 to day 10) and at different incubation temperature (20oC, 25oC, 30oC, 35oC and 40oC). Seven day fermentation at 30oC yield higher enzyme activity for all the enzymes except for amylase activity. Amylase activity was almost twice higher at 35oC compared to ii 30oC. BSG was mixed with different percentage of SCB and SMC separately, to study the effect of mixed substrates in enzyme activity. However, the mixed substrate showed lowed enzyme activity compared to single substrate. Four chemicals namely,CoCl2, CuSO4, MnSO4 and FeSO4 with five concentrations (2 g/l, 4 g/l, 6 g/l, 8 g/l and 10 g/l) used in BSG cultivated with A. niger and S. commune to study the effect of chemicals in enzyme activity induction. Both fungi showed a positive result for the chemical induction. However, S. commune showed higher enzyme activity for cellulase, laccase, lignin peroxidase and xylanase compared to A. niger. BSG fermented with A. niger and S. commune with 10 g/l CoCl2 showed highest amylase and laccase activity respectively. CuSO4 at 4 g/l and 6 g/l showed highest xylanase and cellulase activity respectively in BSG fermented by S. commune. While 6 g/l MnSO4 showed highest lignin peroxidise activity in BSG fermented by S. commune. Therefore, the optimal chemical concentration for each enzyme varies. Fungal biomass was determined by estimating the glucosamine content to perform kinetics of SSF. Consequently the fungal growth rate and fungal half-life was also determined by using first-order kinetic equation. The growth of fungus was correlated with laccase and lignin peroxidase activity, where A. niger, S. commune and Fusarium sp. showed a strong linear correlation with these enzymes. It is evident that, BSG can be utilized as a substrate in SSF for enzyme production

Drag reduction efficiency of solid particles in pipelines of two phase flow

Pipe is a common channel to transport fluid from one location to another. Skin frictions formed by turbulent flow in pipe become the main aspect for researchers to explore the field of fluid mechanics. Frictional drag formed in pipelines transporting water can be reduced spectacularly by adding minute amount of drag reducing agents (DRA). Experiments have been conducted to test the performance of titanium dioxide manufacturing wastes (red gypsum) as DRA. The purpose of using an industrial waste is to reduce the amount of waste land filled (waste to wealth) as well as the capability of red gypsum which doesn't influence or change the properties of water. Investigated parameters for this study are solid concentrations (50ppm-200ppm), pipe diameter (0.0127m, 0.0254m and 0.0381m), length of testing section and Reynolds number (Re) or known as fluid flow rate. The results showed that, percentage drag reduction (%DR) increases by increasing the solid concentration at larger pipe with higher water flow rate (Re). A maximum drag reduction of 56.44% has been achieved in 0.0381m pipe diameter at Re=149648.3 and 200 ppm solid concentrations. On the other hand, while testing the effect of pipe length, effective %DR (40.18%) accomplished at 2m (for 200ppm solid concentration). With demonstrated experimental results, it can be concluded that red gypsum regarded as DRA

Studying the potential of slag waste particle as suspended solid drag reducing agent

Main by product in ore smelting which is slag from tin production in Malaysia has become a trigger for this investigation. Slag waste can be categorized as suspended solid. Utilization of this waste in transportation of fluid can reduce the pressure drop in pipelines. Several studies have shown that addition of minute quantities of suspended solid additives can reduce the drag in pipe and maintain the pressure drop along the pipelines. Experimental works have been conducted in the laboratory in order to test slag waste in a closed loop of turbulence water flowing system. Flow tests were conducted using water as the transport liquid. The experimental work starts by pumping water from reservoir tank that had mixed with slag powder was pumped with varies flow rates in two different pipe diameters (0.025 m ID and 0.038 m D.I). The types of pipe used are PVC pipe. The testing length of this flow system is 2.0 m. The pressure drop and drag reduction were measured in the flow varying concentrations of suspended solid (slag). After adding the suspended solid to the water, the results have shown that the percentage drag reduction (Dr%) over 60% in certain range and condition. This experiment has proven that slag waste particle can be a potential drag reducer in flow system

Start-up of modified anaerobic baffled reactor for the treatment of landfill leachate by using granular sludge

The objective of this study was to valuate the start-up performance of the Modified Anaerobic Baffled Reactor (MABR) system by using granular sludge treating landfill leachate. Anaerobic reactor start-up is a complex process as it depends on the substrate characteristics, working conditions, inoculum and reactor configuration. To reduce the start-up time and have better operational parameters control in anaerobic processes, important factors are needed to enhance the high-rate anaerobic systems efficiency. Sludge granulation was indeed an achievement in anaerobic wastewater treatment technology and has greatly enhanced its efficiency and applicability. It holds many advantages, such as mutual defence against antagonists, efficient reactor operation without sludge washout, and effluent with low suspended solids. Granules are the functional units which comprise different microorganisms that are required for the methanogenic degradation of organic matter. Results from this study showed a successful start-up of the MABR system at an organic loading rate (OLR) of 0.0875 kgCOD/m3/d and hydraulic retention time (HRT) of four days. During this period the Chemical Oxygen Demand (COD) removal efficiency was 99 % and the gas production increased steadily from 0.013 L/d to 0.021 L/d

Bioremediation potential of macroalgae gracilaria edulis and gracilaria changii co-cultured with shrimp wastewater in an outdoor water recirculation system

Effluent from the aquaculture industry discharged into water bodies and it impacts the environment severely. The shrimp industry is one of the developing aquacultures that releases a high amount of organic matters in the form of wastewater. As an effort to reduce the environmental impact, an integrated system with shrimp and macroalgae researched abundantly as the macroalgae are naturally capable of removing nutrient from wastewater. As a bioremediation potential, this study investigates the nutrient uptake and macroalgal growth performance in short term (21 days) using an outdoor recirculating water system stocked with two local macroalgae species Gracilaria edulis and Gracilaria changii as biofilter. The stocking density of 3 kg/m2with the flow rate of the water system set to 200 L/hr during the operation. The temperature, pH, dissolved oxygen (DO) and salinity was measured daily throughout the experimental period. Water temperature in all tanks were almost constant and ranged between 28.5 °C to 29.1 °C. The higher mean of pH of around 8.26 ± 0.15 and 8.28 ± 0.05 was observed in tanks with G. edulis and G. changii respectively. In the control tanks, mean pH was 7.87 ± 0.09. The mean concentrations of dissolved oxygen in G. edulis, G. changii and control tanks were 6.89 ± 0.05 mg/L, 6.84 ± 0.06 mg/L, and 6.10 ± 0.03 mg/L respectively. The mean growth rates of Gracilaria edulis and Gracilaria changii were found to be 4.3% day−1, 4.1% day−1 with carbon to nitrogen (C:N) ratio of 8.3 to 8.5 respectively. The removal rate of ammonium and nitrate by the two species were found to be 72.5%, 71.0%, and 58.8%, 56.8% respectively. The macroalgal biofilter is found to be an ecologically sustainable that has improved the shrimp water quality to an acceptable level that in turn ultimately enhanced shrimp and macroalgae productivity