The production of renewable biofuel through microalgae and green technology can be a promising solution to meet future energy demands whilst reducing greenhouse gases (GHG) emissions and recovering energy for a carbon-neutral bio-economy and environmental sustainability. Recently, the integration of Energy Informatics (EI) technology as an emerging approach has ensured the feasibility and enhancement of microalgal biotechnology and bioenergy applications. Integrating EI technology such as artificial intelligence (AI), predictive modelling systems and life cycle analysis (LCA) in microalgae field applications can improve cost, efficiency, productivity and sustainability. With the approach of EI technology, data-driven insights and decision-making, resource optimization and a better understanding of the environmental impact of microalgae cultivation could be achieved, making it a crucial step in advancing this field and its applications. This review presents the conventional technologies in the microalgae-based system for wastewater treatment and bioenergy production. Furthermore, the recent integration of EI in microalgal technology from the AI application to the modelling and optimization using predictive control systems has been discussed. The LCA and techno-economic assessment (TEA) in the environmental sustainability and economic point of view are also presented. Future challenges and perspectives in the microalgae-based wastewater treatment to bioenergy production integrated with the EI approach, are also discussed in relation to the development of microalgae as the future energy source.
Polycyclic aromatic hydrocarbons (PAHs) and linear alkylbenzenes (LABs) were used as anthropogenic markers of organic chemical pollution of sediments in the Selangor River, Peninsular Malaysia. This study was conducted on sediment samples from the beginning of the estuary to the upstream river during dry and rainy seasons. The concentrations of ƩPAHs and ƩLABs ranged from 203 to 964 and from 23 to 113 ng g(-1) dry weight (dw), respectively. In particular, the Selangor River was found to have higher sedimentary levels of PAHs and LABs during the wet season than in the dry season, which was primarily associated with the intensity of domestic wastewater discharge and high amounts of urban runoff washing the pollutants from the surrounding area. The concentrations of the toxic contaminants were determined according to the Sediment Quality Guidelines (SQGs). The PAH levels in the Selangor River did not exceed the SQGs, for example, the effects range low (ERL) value, indicating that they cannot exert adverse biological effects.
Matched MeSH terms: Water Pollutants, Chemical/analysis*; Water Pollutants, Chemical/chemistry; Water Quality; Waste Water/chemistry
This case study uses several univariate and multivariate statistical techniques to evaluate and interpret a water quality data set obtained from the Klang River basin located within the state of Selangor and the Federal Territory of Kuala Lumpur, Malaysia. The river drains an area of 1,288 km(2), from the steep mountain rainforests of the main Central Range along Peninsular Malaysia to the river mouth in Port Klang, into the Straits of Malacca. Water quality was monitored at 20 stations, nine of which are situated along the main river and 11 along six tributaries. Data was collected from 1997 to 2007 for seven parameters used to evaluate the status of the water quality, namely dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, suspended solids, ammoniacal nitrogen, pH, and temperature. The data were first investigated using descriptive statistical tools, followed by two practical multivariate analyses that reduced the data dimensions for better interpretation. The analyses employed were factor analysis and principal component analysis, which explain 60 and 81.6% of the total variation in the data, respectively. We found that the resulting latent variables from the factor analysis are interpretable and beneficial for describing the water quality in the Klang River. This study presents the usefulness of several statistical methods in evaluating and interpreting water quality data for the purpose of monitoring the effectiveness of water resource management. The results should provide more straightforward data interpretation as well as valuable insight for managers to conceive optimum action plans for controlling pollution in river water.
Matched MeSH terms: Water Pollutants, Chemical/analysis*; Water Pollution, Chemical/statistics & numerical data*; Water Quality/standards*
The Malaysian palm oil industry is a major revenue earner and the country is ranked as one of the largest producers in the world. However, growth of the industry is synonymous with a massive production of agro-industrial wastewater. As an environmental protection and public health concern, the highly polluting palm oil mill effluent (POME) has become a major attention-grabber. Hence, the industry is targeting for POME pollution abatement in order to promote a greener image of palm oil and to achieve sustainability. At present, most palm oil mills have adopted the ponding system for treatment. Due to the successful POME pollution abatement experiences, Malaysia is currently planning to revise the effluent quality standards towards a more stringent discharge limits. Hence, the current trend of POME research focuses on developing tertiary treatment or polishing systems for better effluent management. Biotechnologically-advanced POME tertiary (polishing) technologies as well as other physicochemical methods are gaining much attention as these processes are the key players to push the industry towards the goal of environmental sustainability. There are still ongoing treatment technologies being researched and the outcomes maybe available in a while. However, the research completed so far are compiled herein and reported for the first time to acquire a better perspective and insight on the subject with a view of meeting the new standards. To this end, the most feasible technology could be the combination of advanced biological processes (bioreactor systems) with extended aeration, followed by solids separation prior to discharge. Chemical dosing is favoured only if effluent of higher quality is anticipated.
Matched MeSH terms: Water Pollutants, Chemical/metabolism*; Water Purification/methods*; Waste Water/analysis*
Many industries discharge untreated wastewater into the environment. Heavy metals from many industrial processes end up as hazardous pollutants of wastewaters.Heavy metal pollution has increased in recent decades and there is a growing concern for the public health risk they may pose. To remove heavy metal ions from polluted waste streams, adsorption processes are among the most common and effective treatment methods. The adsorbents that are used to remove heavy metal ions from aqueous media have both advantages and disadvantages. Cost and effectiveness are two of the most prominent criteria for choosing adsorbents. Because cost is so important, great effort has been extended to study and find effective lower cost adsorbents.One class of adsorbents that is gaining considerable attention is agricultural wastes. Among many alternatives, palm oil biomasses have shown promise as effective adsorbents for removing heavy metals from wastewater. The palm oil industry has rapidly expanded in recent years, and a large amount of palm oil biomass is available. This biomass is a low-cost agricultural waste that exhibits, either in its raw form or after being processed, the potential for eliminating heavy metal ions from wastewater. In this article, we provide background information on oil palm biomass and describe studies that indicate its potential as an alternative adsorbent for removing heavy metal ions from wastewater. From having reviewed the cogent literature on this topic we are encouraged that low-cost oil-palm-related adsorbents have already demonstrated outstanding removal capabilities for various pollutants.Because cost is so important to those who choose to clean waste streams by using adsorbents, the use of cheap sources of unconventional adsorbents is increasingly being investigated. An adsorbent is considered to be inexpensive when it is readily available, is environmentally friendly, is cost-effective and be effectively used in economical processes. The advantages that oil palm biomass has includes the following:available and exists in abundance, appears to be effective technically, and can be integrated into existing processes. Despite these advantages, oil palm biomasses have disadvantages such as low adsorption capacity, increased COD, BOD and TOC. These disadvantages can be overcome by modifying the biomass either chemically or thermally. Such modification creates a charged surface and increases the heavy metal ion binding capacity of the adsorbent.
Matched MeSH terms: Water Pollutants, Chemical/isolation & purification*; Water Purification/methods*; Waste Water/chemistry*
A two-staged engineered wetland-based system was designed and constructed to treat raw domestic septage. Hydraulic loading rates (HLRs) of 8.75 and 17.5 cm/d were studied with four and eight daily dosings at the second stage of the system to investigate the influence of the regimes on septage treatment. Removal of organic matter (OM) was found to be HLR dependent, where the results indicated that the increase of HLR from 8.75 to 17.5 cm/d impaired the overall level of treatment in the wetland units. Effluent of wetland fed at HLR 17.5 cm/d presented significantly lower oxygen reduction potential and dissolved oxygen values than wetland fed at 8.75 cm/d, indicative of the occurrence of less aerobic and reductive conditions in the bed. The reoxygenation capability of the wetland units was found to be heavily affected by the dosing frequency especially under high hydraulic load (17.5 cm/d). NH3-N degradation was found to decrease with statistical importance when the wetland was flushed two times more frequently with smaller batches of influent. The number of hydraulic load fractionings did not seem to affect the level of treatments of OM and ammonia for both the wetlands fed under the lower HLR of 8.75 cm/d. Prediction of hydraulic limits and management of the feeding strategies are important in the vertical type of engineered wetlands to guarantee the treatment performance and minimize the chances of filter clogging.
Matched MeSH terms: Water Pollutants, Chemical/metabolism; Water Purification/methods; Waste Water*
Despite the amount of awareness created, waterborne disease still poses threat, especially in developing countries. Due to the scarcity of reported data on waterborne parasites, the consumption of unsafe water prolongs. Thus, the occurrences of waterborne parasites from various samples were investigated from one of the Southeast Asian country, the Philippines.
Matched MeSH terms: Fresh Water/parasitology*; Water Supply/standards*; Water Quality*
A greener method based on cloud point extraction was developed for removing phenol species including 2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP) and 4-nitrophenol (4-NP) in water samples by using the UV-Vis spectrophotometric method. The non-ionic surfactant DC193C was chosen as an extraction solvent due to its low water content in a surfactant rich phase and it is well-known as an environmentally-friendly solvent. The parameters affecting the extraction efficiency such as pH, temperature and incubation time, concentration of surfactant and salt, amount of surfactant and water content were evaluated and optimized. The proposed method was successfully applied for removing phenol species in real water samples.
Matched MeSH terms: Water/analysis; Water Pollutants, Chemical/isolation & purification*; Water Purification/methods*
Rivers play a significant role in providing water resources for human and ecosystem survival and health. Hence, river water quality is an important parameter that must be preserved and monitored. As the state of Selangor and the city of Kuala Lumpur, Malaysia, are undergoing tremendous development, the river is subjected to pollution from point and non-point sources. The water quality of the Klang River basin, one of the most densely populated areas within the region, is significantly degraded due to human activities as well as urbanization. Evaluation of the overall river water quality status is normally represented by a water quality index (WQI), which consists of six parameters, namely dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, suspended solids, ammoniacal nitrogen and pH. The objectives of this study are to assess the water quality status for this tropical, urban river and to establish the WQI trend. Using monthly WQI data from 1997 to 2007, time series were plotted and trend analysis was performed by employing the first-order autocorrelated trend model on the moving average values for every station. The initial and final values of either the moving average or the trend model were used as the estimates of the initial and final WQI at the stations. It was found that Klang River water quality has shown some improvement between 1997 and 2007. Water quality remains good in the upper stream area, which provides vital water sources for water treatment plants in the Klang valley. Meanwhile, the water quality has also improved in other stations. Results of the current study suggest that the present policy on managing river quality in the Klang River has produced encouraging results; the policy should, however, be further improved alongside more vigorous monitoring of pollution discharge from various point sources such as industrial wastewater, municipal sewers, wet markets, sand mining and landfills, as well as non-point sources such as agricultural or urban runoff and commercial activity.
Matched MeSH terms: Water Pollutants, Chemical/analysis*; Water Pollution, Chemical/statistics & numerical data*; Water Quality/standards*
Surface water is one of the essential resources for supporting sustainable development. The suitability of such water for a given use depends both on the available quantity and tolerable quality. Temporary status for a surface water quality has been identified extensively. Still the suitability of the water for different purposes needs to be verified. This study proposes a water quality evaluation system to assess the aptitude of the Selangor River water for aquatic biota, drinking water production, leisure and aquatic sport, irrigation use, livestock watering, and aquaculture use. Aptitude of the water has been classified in many parts of the river segment as unsuitable for aquatic biota, drinking water production, leisure and aquatic sport as well as aquaculture use. The water quality aptitude classes of the stream water for nine locations along the river are evaluated to contribute to decision support system. The suitability of the water for five different uses and its aquatic ecosystem are verified.
Matched MeSH terms: Water Pollutants, Chemical/analysis*; Water Pollution, Chemical/statistics & numerical data; Water Supply/statistics & numerical data*
Photocatalytic oxidation of crosslinked chitosan-epichlorohydrin (CS-ECH) film was successfully achieved via an immobilized TiO2/CS-ECH photocatalyst system on a glass plate. Oxidation process of CS-ECH film was carried out by irradiating the system with a 45-W fluorescent lamp for 10h in ultra-pure water. The results indicate the formation of carbonyl functional groups and partial elimination of amine groups in the molecular structure of the oxidized CS-ECH film. This oxidized CS-ECH film has different optical properties, ionic conductivity, degree of transparency, swelling index and chemical stability than the fresh CS-ECH film. In the environmental applications, the TiO2/oxidized-CS-ECH photocatalyst system can have photodegradation and faster mineralization rate of phenol than both fresh TiO2/CS-ECH and TiO2/oxidized-CS photocatalyst systems. This simple photocatalyst system, therefore can be considered as an environmental friendly method to oxidize synthetic biopolymer and to improve the photocatalytic efficiency of TiO2 to treat wastewater.
Matched MeSH terms: Water Pollutants, Chemical/isolation & purification*; Water Purification/methods; Waste Water/analysis*
Perfluorinated compounds such as perfluorooctane sulfonate (PFOS) and perfluorooctane acid (PFOA) have been recognized as emerging environmental pollutants because of their ubiquitous occurrence in the environment, biota and humans. The paper focuses on the distribution, bioaccumulation and toxic effects of PFOS and PFOA in the water. From the available literature, tap and surface water samples in several countries were found to be contaminated with PFOS and PFOA. These compounds were detected globally in the tissues of fish, bird and marine mammals. Their concentrations from relatively more industrialized areas were greater than those from the less populated and remote locations. Blood samples of occupationally exposed people and the general population in various countries were found to contain PFOS and PFOA which suggested a possibility of atmospheric transport of these compounds. There is still a death of information about the environmental pathways of PFOS and PFOA. The presence of these compounds in the tap water, surface water and animal and human tissues indicates their global contamination and bioaccumulative phenomena in the ecosystems.
Matched MeSH terms: Water/metabolism*; Water Pollutants, Chemical/blood; Water Pollutants, Chemical/metabolism*; Water Pollutants, Chemical/toxicity*
The study was to determine the concentration of aluminium (Al) and study the physicochemical parameters (pH, total dissolved solids (TDS), turbidity, and residual chlorine) in drinking water supply in selected palm oil estates in Kota Tinggi, Johor. Water samples were collected from the estates with the private and the public water supplies. The sampling points were at the water source (S), the treatment plant outlet (TPO), and at the nearest houses (H1) and the furthest houses (H2) from the TPO. All estates with private water supply failed to meet the NSDWQ for Al with mean concentration of 0.99 ± 1.52 mg/L. However, Al concentrations in all public water supply estates were well within the limit except for one estate. The pH for all samples complied with the NSDWQ except from the private estates for the drinking water supply with an acidic pH (5.50 ± 0.90). The private water supply showed violated turbidity value in the drinking water samples (14.2 ± 24.1 NTU). Insufficient amount of chlorination was observed in the private water supply estates (0.09 ± 0.30 mg/L). Private water supplies with inefficient water treatment served unsatisfactory drinking water quality to the community which may lead to major health problems.
Matched MeSH terms: Water Pollutants, Chemical/analysis*; Water Quality*; Drinking Water/analysis*
Leachate pollution is one of the main problems in landfilling. Researchers have yet to find an effective solution to this problem. The technology that can be used may differ based on the type of leachate produced. Coliform bacteria were recently reported as one of the most problematic pollutants in semi-aerobic (stabilized) leachate. In the present study, the performance of the Electro-Fenton process in removing coliform from leachate was investigated. The study focused on two types of leachate: Palau Borung landfill leachate with low Coliform content (200 MPN/100 m/L) and Ampang Jajar landfill leachate with high coliform content (>24 × 10(4)MPN/100 m/L). Optimal conditions for the Electro-Fenton treatment process were applied on both types of leachate. Then, the coliform was examined before and after treatment using the Most Probable Number (MPN) technique. Accordingly, 100% removal of coliform was obtained at low initial coliform content, whereas 99.9% removal was obtained at high initial coliform content. The study revealed that Electro-Fenton is an efficient process in removing high concentrations of pathogenic microorganisms from stabilized leachate.
Matched MeSH terms: Water Microbiology*; Water Pollutants, Chemical/chemistry*; Water Purification/methods*
A batch adsorption system was applied to study the adsorption of Fe(II) and Fe(III) ions from aqueous solution by chitosan and cross-linked chitosan beads. The adsorption capacities and rates of Fe(II) and Fe(III) ions onto chitosan and cross-linked chitosan beads were evaluated. Chitosan beads were cross-linked with glutaraldehyde (GLA), epichlorohydrin (ECH) and ethylene glycol diglycidyl ether (EGDE) in order to enhance the chemical resistance and mechanical strength of chitosan beads. Experiments were carried out as function of pH, agitation period, agitation rate and concentration of Fe(II) and Fe(III) ions. Langmuir and Freundlich adsorption models were applied to describe the isotherms and isotherm constants. Equilibrium data agreed very well with the Langmuir model. The kinetic experimental data correlated well with the second-order kinetic model, indicating that the chemical sorption was the rate-limiting step. Results also showed that chitosan and cross-linked chitosan beads were favourable adsorbers.
Matched MeSH terms: Water/chemistry*; Water Pollutants, Chemical/isolation & purification*; Water Purification/methods*
This study analyzes the effects of toxic, hydraulic, and organic shocks on the performance of a lab-scale sequencing batch reactor (SBR) with a capacity of 5L. Petroleum refinery wastewater (PRWW) was treated with an organic loading rate (OLR) of approximately 0.3 kg chemical oxygen demand (COD)/kg MLSSd at 12.8h hydraulic retention time (HRT). A considerable variation in the COD was observed for organic, toxic, hydraulic, and combined shocks, and the worst values observed were 68.9, 77.1, 70.2, and 57.8%, respectively. Improved control of toxic shock loads of 10 and 20mg/L of chromium (VI) was identified. The system was adversely affected by the organic shock when a shock load thrice the normal value was used, and this behavior was repeated when the hydraulic shock was 4.8h HRT. The empirical recovery period was greater than the theoretical period because of the inhibitory effects of phenols, sulfides, high oil, and grease in the PRWW. The system recovery rates from the shocks were in the following order: toxic, organic, hydraulic, and combined shocks. System failure occurred when the combined shocks of organic and hydraulic were applied. The system was resumed by replacing the PRWW with glucose, and the OLR was reduced to half its initial value.
Matched MeSH terms: Water Pollutants, Chemical/chemistry; Water Purification/methods; Waste Water/chemistry*
A novel preparation method of magnetized palm shell waste-based powdered activated carbon (MPPAC, avg. size 112 μm) was developed. The prepared MPPAC was assessed by several physicochemical analyses, and batch tests were performed for ibuprofen (IBP) removal. Field emission scanning electron microscopy (FESEM) and N2 gas isotherms revealed that magnetite and maghemite were homogeneous and deposited mostly on the surface of PPAC without a significant clogging effect on the micropores. Isotherm results showed that 3.8% Fe (w/w) impregnated PPAC [MPPAC-Fe(3.8%)] had about 2.2-fold higher maximum sorption capacity (157.3 mg g-1) and a 2.5-fold higher sorption density (0.23 mg m-2) than pristine PPAC. Both Fourier-transform infrared spectroscopy (FTIR) and isotherm data indicated that the high sorption capacity and density of IBP by MPPAC was primarily attributable to donor-acceptor complexes with the C = O group and dispersive π-π interactions with the carbon surface. Based on kinetic and repeated adsorption tests, pore diffusion was the rate-limiting step, and MPPAC-Fe(3.8%) had about 1.9~2.8- and 9.1~15.8-fold higher rate constants than MPPAC-Fe(8.6%) and palm shell-waste granular activated carbon (PGAC, avg. size 621 μm), respectively. MPPAC showed almost eight fold greater re-adsorption capacity than PPAC due to a thermal catalytic effect of magnetite/maghemite.
Matched MeSH terms: Fresh Water/chemistry*; Water Pollutants, Chemical/isolation & purification*; Water Purification/methods*
In this study, durian (Durio zibethinus Murray) skin was examined for its ability to remove methylene blue (MB) dye from simulated textile wastewater. Adsorption equilibrium and kinetics of MB removal from aqueous solutions at different parametric conditions such as different initial concentrations (2-10 mg/L), biosorbent dosages (0.3-0.7 g) and pH solution (4-9) onto durian skin were studied using batch adsorption. The amount of MB adsorbed increased from 3.45 to 17.31 mg/g with the increase in initial concentration of MB dye; whereas biosorbent dosage increased from 1.08 to 2.47 mg/g. Maximum dye adsorption capacity of the durian skin was found to increase from 3.78 to 6.40 mg/g, with increasing solution pH. Equilibrium isotherm data were analyzed according to Langmuir and Freundlich isotherm models. The sorption equilibrium was best described by the Freundlich isotherm model with maximum adsorption capacity of 7.23 mg/g and this was due to the heterogeneous nature of the durian skin surface. Kinetic studies indicated that the sorption of MB dye tended to follow the pseudo second-order kinetic model with promising correlation of 0.9836 < R(2) < 0.9918.
Matched MeSH terms: Water/chemistry*; Water Pollutants, Chemical/chemistry*; Water Purification/methods*
Effects of biological activated carbon (BAC), biological aerated filter (BAF), alum coagulation and Moringa oleifera coagulation were investigated to remove iron and arsenic contaminants from drinking water. At an initial dose of 5 mg/L, the removal efficiency for arsenic and iron was 63% and 58% respectively using alum, and 47% and 41% respectively using Moringa oleifera. The removal of both contaminants increased with the increase in coagulant dose and decrease in pH. Biological processes were more effective in removing these contaminants than coagulation. Compared to BAF, BAC gave greater removal of both arsenic and iron, removing 85% and 74%, respectively. Longer contact time for both processes could reduce the greater concentration of arsenic and iron contaminants. The addition of coagulation (at 5 mg/L dosage) and a biological process (with 15 or 60 min contact time) could significantly increase removal efficiency, and the maximum removal was observed for the combination of alum and BAC treatment (60 min contact time), with 100% and 98.56% for arsenic and iron respectively. The reduction efficiency of arsenic and iron reduced with the increase in the concentration of dissolved organics in the feedwater due to the adsorption competition between organic molecules and heavy metals.
Matched MeSH terms: Water Pollutants, Chemical/chemistry*; Water Purification/methods*; Drinking Water/analysis*
The adsorption behavior of chitosan (CS) beads modified with 3-aminopropyl triethoxysilane (APTES) for the removal of reactive blue 4 (RB4) in batch studies has been investigated. The effects of modification conditions, such as the APTES concentration, temperature and reaction time on RB4 removal, were studied. The adsorbent prepared at a concentration of 2 wt% APTES for 8h at 50 °C was the most effective one for RB4 adsorption. The adsorption capacity of modified CS beads (433.77 mg/g) was 1.37 times higher than that of unmodified CS beads (317.23 mg/g). The isotherm data are adequately described by a Freundlich model, and the kinetic study revealed that the pseudo-second-order rate model was in better agreement with the experimental data. The negative values of the thermodynamic parameters, including ΔG° (-2.28 and -4.70 kJ/mol at 30 ± 2 °C), ΔH° (-172.18 and -43.82 kJ/mol) and ΔS° (-560.71 and -129.08 J/mol K) for CS beads and APTES modified beads, respectively, suggest that RB4 adsorption is a spontaneous and exothermic process.
Matched MeSH terms: Water/analysis; Water Pollutants, Chemical/isolation & purification*; Water Purification/methods