Discharge Regulations Research Articles

Performance evaluation on ultrafiltration as tertiary treatment for rubber glove wastewater

Ultrafiltration (UF) is a promising treatment solution used for tertiary treatment of industrial wastewater. However, membrane fouling is the major problem which limits the performance of the UF in industry. In the present study, the operational and separation performane of ultrafiltration of biologically treated rubber glove wastewater were carried out using innovative developed organic metal membranes. Two types of commercial PolyCera® Titan (70 kDa) and PolyCera® Hydro (100 kDa) flat sheet UF membrane were applied for tertiary treatment of rubber glove wastewater. The physicochemical properties of influent and UF membranes were characterized before and after the treatment process. PolyCera® Titan membranes have slightly higher hydrophobicity, lower permeability and lower fouling tendency as compared to PolyCera® Hydro membrane. PolyCera® Titan gave higher COD, TSS, and color rejection, observed at 66.9%, 73.3%, and 82.4%, respectively. The permeate quality conformed with the regulatory discharge standard, except for the PolyCera® Hydro membrane in which the COD value surpassed the permissible limit. With its promising performance, PolyCera® membranes have great potential to reduce pollutant loading in the wastewater for efficient rubber glove wastewater treatment.

Functional diversity of benthic macroinvertebrates regarding hydrological and land use disturbances in a heavily impaired lowland river

This paper proposes the exploration functional diversity of benthic macroinvertebrates to evaluate their response to hydrological and land use stressors in a semi-arid lowland river. We aim to assess dominant functional traits and their sensitivity to environmental drivers, and how functional diversity respond to anthropogenic ecosystem impacts. Environment was evaluated through physical-chemical characterization of water, substrate and hydrological indices. For riparian condition assessment, we applied the QBR index for riparian forest quality and hemeroby index for level of anthropogenic intervention on the landscape. Links between environmental variables (R), taxa distribution (L) and trait composition (Q) were examined with RLQ and combined with fourth-corner analysis. The principal disturbance gradient was related to discharge regulation overlapping with land use represented by hemeroby index. There was also a gradient related to the hydrological regime which alternates seasonal floods with low flow periods. Traits related to reproductive and dispersal strategies were the most influenced by disturbance gradients, both natural and anthropogenic. Functional diversity decrease in sites subject to water abstraction and with higher hemeroby levels. Our findings have been promising in order to the application of functional diversity for biomonitoring in the Dulce River. Hemeroby enables the identification of trending changes between land uses, as well as to identify threat contexts. Furthermore, hemeroby could be useful in diagnostic stages to propose biomonitoring sites, by setting areas with different anthropogenic intervention on the ecosystem.

Produced Water Treatment with Conventional Adsorbents and MOF as an Alternative: A Review.

A large volume of produced water (PW) has been produced as a result of extensive industrialization and rising energy demands. PW comprises organic and inorganic pollutants, such as oil, heavy metals, aliphatic hydrocarbons, and radioactive materials. The increase in PW volume globally may result in irreversible environmental damage due to the pollutants’ complex nature. Several conventional treatment methods, including physical, chemical, and biological methods, are available for produced water treatment that can reduce the environmental damages. Studies have shown that adsorption is a useful technique for PW treatment and may be more effective than conventional techniques. However, the application of adsorption when treating PW is not well recorded. In the current review, the removal efficiencies of adsorbents in PW treatment are critically analyzed. An overview is provided on the merits and demerits of the adsorption techniques, focusing on overall water composition, regulatory discharge limits, and the hazardous effects of the pollutants. Moreover, this review highlights a potential alternative to conventional technologies, namely, porous adsorbent materials known as metal–organic frameworks (MOFs), demonstrating their significance and efficiency in removing contaminants. This study suggests ways to overcome the existing limitations of conventional adsorbents, which include low surface area and issues with reuse and regeneration. Moreover, it is concluded that there is a need to develop highly porous, efficient, eco-friendly, cost-effective, mechanically stable, and sustainable MOF hybrids for produced water treatment.

Assessment of the possibility of operating low-pressure hydroelectric facilities in order to improve the conditions of navigation in their lower reaches

The paper provides an assessment of the projected low-pressure hydroelectric facility operation on the Volga River from the point of view of navigation conditions in its lower reach. The operating mode of the low-pressure hydroelectric facility completely depends on the hourly discharges of the Nizhny Novgorod HPP, located upstream. Significant unevenness in time of the supplied discharges from the Nizhny Novgorod HPP, which, repeating itself when discharging flows into the lower reach of the Nizhniy Novgorod low-pressure hydroelectric facility, can lead to negative consequences for shipping in terms of failure to provide transport passes and necessary depths. It is proposed to reduce the unevenness of discharges by introducing diurnal flow regulation into the low-pressure hydroelectric facility operation, aimed at changing the hydrological regime of the river section to improve the conditions and organize uninterrupted and safe navigation in the lower reach. Achievement of the regulation goal associated with minimization of interval deviations of the supplied flow rates from Nizhny Novgorod HPP from the daily average values and the fulfillment of the restrictions on the hydrological regime of the low-pressure hydroelectric facility ponds, is achieved by two control options (three-stage and two-stage). The study used the methods of mathematical statistics and probability theory, optimization of management decisions. The methodology of the mathematical model limitations’ nonfulfillment elimination for solving the problem and optimization of the low-pressure hydroelectric facility daily hydrograph is presented. Using a specific example, the problem of diurnal regulation of discharges is solved and the obtained effect is described.

Serotonin Discharge Regulation by Additional Neurotransmitters of Rat Hippocampus Associated With the Continence Central Circuit.

PurposeThe lower urinary tract is believed to be centrally regulated with the involvement of a range of neurotransmitters. The parasympathetic excitatory input to the urinary bladder is suppressed when the serotonergic system is activated, and thereby voiding is blocked. In healthy people, continence is usually underpinned by hippocampal formation (circuit 3). In order to advance knowledge of how serotoninergic neurons and additional nerve fibers were correlated, the purpose of the present work was to research how the discharge of serotonin from hippocampal slices was affected by different neurotransmitters in rat models.MethodsThe adopted procedure involved administration of the central neurotransmitters acetylcholine, norepinephrine, dopamine, N-methyl-D-aspartate (NMDA), gamma-aminobutyric acid (GABA), glycine, and neuropeptide Y as well as monitoring of the alterations in the discharge of [3H]5-hydroxytryptamine (5-HT). Furthermore, to determine whether the effect of the neurotransmitters was influenced by interneuron, tetrodotoxin was also employed.ResultsAcetylcholine (10-5M) did not alter [3H]5-HT discharge, whereas more 5-HT was discharged from the hippocampal slices of rats under stimulation by norepinephrine (10-5M) as well as dopamine (10-5M) and tetrodotoxin (10-6M) did not inhibit the discharge. By contrast, tetrodotoxin inhibited the discharge of [3H]5-HT that was exacerbated by NMDA (10-4M). Meanwhile, compared to control, GABA (10-5M), glycine (10-5M), or neuropeptide Y (10-6M) did not alter the [³H]5-HT discharge.ConclusionsFrom the research findings, it can be concluded that 5-HT discharge from rat hippocampus is enhanced by norepinephrine and dopamine through direct effect on the 5-HT neuronal terminal. By contrast, 5-HT discharge is intensified by NMDA by activating interneurons.

Landscape of genes in hospital wastewater breaking through the defense line of last-resort antibiotics

Hospital wastewater contains abundant antibiotics, antibiotic resistance genes (ARGs), and pathogens. Last-resort antibiotic resistance genes (LARGs) include the New Delhi metallo-β-lactamase gene blaNDM, mobile colistin resistance gene mcr and tigecycline resistance gene tet(X) which confers resistance to carbapenems, colistin and tigecycline. The presence and significance of LARGs in hospital wastewater treatment systems (HWTS) have not yet been systematically explored. Here, LARG variants were shown to be prevalent both influents and effluents of HWTS. A total of 989 Enterobacteriaceae isolates that confer resistance to last-resort antibiotics were collected from effluents and multiple genetic contexts of LARGs were analyzed. LARGs-carrying plasmids were confirmed to show high multidrug phenotypes and transferability. We also discovered the co-occurrence of plasmids harboring blaNDM-1 and mcr-1 in single Escherichia coli, as well as E. coli HM016 containing two unique mcr-1-carrying plasmids. This result might accelerate co-dissemination of LARGs under environmental selection pressure. Different core genetic arrangements in these strains suggest several evolutionary pathways in HWTS. The resistance functions of LARGs were confirmed in vitro and in vivo by mass spectrometry. This study provides novel insights into the diversity, genetic context and function of critical ARGs in HWTS. The results raise the concern that LARGs may further spread into the environment, thus, more stringent discharge standards and regulations for hospital wastewater are urgently needed.

Elevated loading rates as a low operational intensity and small land footprint design strategy to achieve partial nitritation

An urgent need exists for cost-effective, low operational intensity and small land footprint ammonia treatment systems to meet stringent wastewater discharge regulations. A moving bed biofilm reactor system operating under a novel design strategy using elevated total ammonia nitrogen (TAN) loading rates ranging from 3 to 6.5 g TAN/m2·d has shown promise to achieve robust partial nitritation (PN) and the oxidation of TAN with limited oxidation of nitrite without the need for intense operational measures. An investigation of the biofilm, the viability of the embedded cells and the microbial ecology is necessary to fully understand this low operational intensity design. The investigation revealed that, at a loading rate of 6.5 g TAN/m2·d, the abundance of nitrite oxidizing bacteria (NOB) was 2 ± 0.46%; however, the NOB activity was negligible with 99 ± 0.2% nitrite accumulation; thus, the mechanism to attain robust PN is shown to be the suppression of NOB activity as opposed to NOB population suppression. This decrease in NOB activity is associated with an increase in thickness and mass of the biofilm, as well as the relative increase in ammonia oxidizing bacteria (AOB) that preferentially uptake oxygen compared to NOB. As such, this design strategy results in the suppression of the NOB activity due to limited access to oxygen via mass transfer limitations through thick biofilm and competition with an augmented AOB population in the biofilm. This research presents a low operational intensity and small footprint PN strategy that can be an effective alternative to more intensive strategies.

Wastewater Discharge and Reuse Regulation in Costa Rica: An Opportunity for Improvement

A database was built with the results of the physicochemical analysis of 23,435 samples of wastewater discharges obtained from the operational reports presented and the cross-checks carried out by the Ministry of Health to the operating entities, in accordance with the provisions of Decree 30661-MINAE-S, for the period 2016–2020. Using Bayesian networks, the probabilities of compliance with current regulations were estimated by preparing an acyclic directed graph for three alternative scenarios. At the national level, the BOD and the COD are the variables that record the lowest values, showing important differences between the results obtained for the central region of the country with respect to the other regions. Another determining variable turned out to be the type of final disposal, wherein the reuse of wastewater presents important compliance deficiencies for all regions except for Chorotega. In the case of BOD, COD and TSS, the lowest probabilities are recorded for ISIC codes 3821 (treatment of non-hazardous waste), 1040 (manufacture of animal and vegetable fats) and 145 (pig farming). Additionally, the integrated environmental risk was calculated as a product of the discharges, obtaining that for the evaluated parameters, the BOD and COD represent the highest risk values given their probability of occurrence rate, as well as the magnitude of the environmental impact. The Pacifico Central and Brunca regions recorded the highest integrated environmental risk value for BOD, COD and TSS compared to the other areas of the country. Based on the results obtained, proposals for improvement were generated for the control of wastewater discharges carried out by the environmental authorities in search of achieving a better comprehensive management of the water resource.

Contemporary Techniques for Remediating Endocrine-Disrupting Compounds in Various Water Sources: Advances in Treatment Methods and Their Limitations.

Over the years, the persistent occurrence of superfluous endocrine-disrupting compounds (EDCs) (sub µg L−1) in water has led to serious health disorders in human and aquatic lives, as well as undermined the water quality. At present, there are no generally accepted regulatory discharge limits for the EDCs to avert their possible negative impacts. Moreover, the conventional treatment processes have reportedly failed to remove the persistent EDC pollutants, and this has led researchers to develop alternative treatment methods. Comprehensive information on the recent advances in the existing novel treatment processes and their peculiar limitations is still lacking. In this regard, the various treatment methods for the removal of EDCs are critically studied and reported in this paper. Initially, the occurrences of the EDCs and their attributed effects on humans, aquatic life, and wildlife are systematically reviewed, as well as the applied treatments. The most noticeable advances in the treatment methods include adsorption, catalytic degradation, ozonation, membrane separation, and advanced oxidation processes (AOP), as well as hybrid processes. The recent advances in the treatment technologies available for the elimination of EDCs from various water resources alongside with their associated drawbacks are discussed critically. Besides, the application of hybrid adsorption–membrane treatment using several novel nano-precursors is carefully reviewed. The operating factors influencing the EDCs’ remediations via adsorption is also briefly examined. Interestingly, research findings have indicated that some of the contemporary techniques could achieve more than 99% EDCs removal.

Targeting economic and environmental benefits associated with the integration of regeneration units in water systems

Water treatment is traditionally seen as an "end-of-pipe" solution to deal with contaminated water satisfying discharge regulations at a minimum expense. However, the reuse of treated water as regenerated water is a promising strategy to counteract water scarcity. This approach to transform waste into resources is motivated by the circular economy paradigm. This study presents a mathematical programming approach to target both the environmental and economic benefits of water systems by introducing additional regeneration units to close the loop. In addition to water users and authorities, the approach also considers operators and dealers, which are revealed as key stakeholders. Hence, the feasible region of the regeneration units design specifications is determined and visualized through a multi-objective optimization approach targeting the systems operating cost and freshwater consumption. Its application is demonstrated on a benchmark case study from the literature, revealing a potential economic benefit of 37.5% and a freshwater reduction of 80.9% over the case without regeneration units. Furthermore, we show that a cooperative exchange strategy leads to higher benefits compared to the solutions presented in the literature. Finally, we demonstrate how the barrier plots introduced in this work can be used by different stakeholders in the water market to support their decision-making.

Life Cycle Assessment of Leachate Treatment Strategies.

Increasingly stringent regulations for leachate discharge call for leachate treatment plants (LTPs) to increase their treatment capacity by adopting membrane treatment processes to remove nitrogen and organics beyond conventional biological treatment processes. This study developed four common treatment strategies based on the existing operation and construction conditions of seven representative LTPs in China. We evaluated the LTPs' environmental impacts using life cycle assessment (LCA) following the International Organization for Standardization (ISO 14040 and ISO 14044). Compared with conventional secondary treatment processes, implementing high-level technologies to meet the strict standards could reduce an average of 59% of the eutrophication potential while increasing other environmental impacts resulting from both direct and indirect emissions by an average of 146%. We propose advanced technologies that integrate both midpoint and endpoint LCA results to meet stringent standards in areas sensitive to eutrophication.

Evolutionary Game Research between the Government Environmental Regulation Intensities and the Pollution Emissions of Papermaking Enterprises

Environmental regulations of different intensities may have different impacts on polluting enterprises. The purpose of this article is to analyze how different environmental regulations affect the pollution discharge strategies of papermaking enterprises. By establishing an evolutionary game model between the government environmental regulation intensities and the pollutant emissions from papermaking enterprises, this thesis further solves the model and performs stability analysis and finally uses MATLAB to conduct simulation studies. And the researching results show that papermaking enterprises will take risks to choose the illegal pollutant discharge strategies when the illegal profits are large. Further analysis shows that the increase in the successful probability of the strong environmental regulations does not necessarily force papermaking enterprises to choose to comply with pollution discharge regulations. However, papermaking enterprises may choose to comply with discharge pollution regulations not only by increasing the successful probability of strong environmental regulations but also by increasing the rewards and punishments for papermaking enterprises as well as by increasing the probability of reporting violations of pollutants. Based on the above results, the author proposes several countermeasures, such as establishing a specialized pollution monitoring agency, encouraging third-party supervision, reporting pollution behaviors, and increasing penalties for polluting companies for violations. China is in a critical period of transition from rapid development to high-quality development. It will provide some reliable references for the construction of a green economy and an ecological economy that the characteristics and relationships between the intensity of government environmental regulations and corporate pollution emissions revealed in this article.

Multi-Integrated Systems for Treatment of Abattoir Wastewater: A Review

Biological wastewater treatment processes such as activated sludge and anaerobic digestion remain the most favorable when compared to processes such as chemical precipitation and ion exchange due to their cost-effectiveness, eco-friendliness, ease of operation, and low maintenance. Since Abattoir Wastewater (AWW) is characterized as having high organic content, anaerobic digestion is slow and inadequate for complete removal of all nutrients and organic matter when required to produce a high-quality effluent that satisfies discharge standards. Multi-integrated systems can be designed in which additional stages are added before the anaerobic digester (pre-treatment), as well as after the digester (post-treatment) for nutrient recovery and pathogen removal. This can aid the water treatment plant effluent to meet the discharge regulations imposed by the legislator and allow the possibility for reuse on-site. This review aims to provide information on the principles of anaerobic digestion, aeration pre-treatment technology using enzymes and a hybrid membrane bioreactor, describing their various roles in AWW treatment. Simultaneous nitrification and denitrification are essential to add after anaerobic digestion for nutrient recovery utilizing a single step process. Nutrient recovery has become more favorable than nutrient removal in wastewater treatment because it consumes less energy, making the process cost-effective. In addition, recovered nutrients can be used to make nutrient-based fertilizers, reducing the effects of eutrophication and land degradation. The downflow expanded granular bed reactor is also compared to other high-rate anaerobic reactors, such as the up-flow anaerobic sludge blanket (UASB) and the expanded granular sludge bed reactor (EGSB).

Comparative evaluation of the macrophytes in the constructed wetlands for the treatment of combined wastewater (greywater and septic tank effluent) in a sub-tropical region

The role of macrophytes in constructed wetlands (CW) has been studied extensively in the last three decades. The remediating effect of macrophytes in CWs depends on whether the species is suitable for the given climatic and operational conditions and on the morphological traits of the species. This study experimentally investigated and compared the contribution of three macrophytes, namely Phragmites karka, Iris kashmiriana, and Sagittaria latifolia in removing pollutants from combined wastewater (greywater and septic effluent) using horizontal sub-surface flow type constructed wetlands (HSSF-CW) under sub-tropical conditions. The study monitored the standard wastewater parameters (COD, Nitrogen, Phosphorus, and Solids) in the inlet and outlet of the CW microcosms, the fate of nutrients through the planted microcosms, and the growth rate of the selected species. Phragmites karka showed better removal efficiencies than the other two species, with organic loading removal rates of 10 ± 1.3 gm−2d−1, nitrogen removal rates of 2.6 ± 0.4 gm−2d−1, phosphorus removal rates of 1.3 ± 0.2 gm−2d−1, and solids removal rates of 3.6 ± 1.2 gm−2d−1. Mass balance showed that the nutrient uptake by species Sagittaria latifolia (TP – 9.3 g and TN – 48.2 g) was the most, followed by Phragmites karka (TP – 8.6 g and TN – 47.9 g) and Iris kashmiriana (TP – 4.4 g and TN – 29.1 g). Biomass analysis revealed that Phragmites karka had the maximum biomass growth rate with an increment of 1383 gm−2: 524 gm−2 in the above-ground: below ground dry biomass weight, while as Sagittaria latifolia and Iris kashmiriana showed an increase of 1299 gm−2: 866 gm−2 and 663 gm−2: 1312 gm−2, respectively. The macrophytes with well-developed root systems (Phragmites karka) had a better pollutant remediating effect. The nutrient uptake by macrophytes depended on the total dry biomass increase and the nutrient content of the biomass. The CW beds of the three macrophytes need nutrient pre- or post-treatment to comply with the irrigation reuse and conventional sewage treatment plant (STP) discharge regulations in India.

Characterization of communities in a microalgae-bacteria system treating domestic wastewater reveals dominance of phototrophic and pigmented bacteria

The consortia formed by microalgae and bacteria developed during semi-continuous operation of photobioreactors treating domestic wastewater was characterized by means of flow cytometry and DGGE techniques. While microalgae population was dominated by the inoculated wild strain Chlorella sorokiniana, the bacterial community included as activated sludge was totally replaced by microbial groups exhibiting adaptations to illuminated environments. The quantification conducted by flow cytometry evidenced bacterial population displacement favoring pigmented and photoheterotrophic groups. This fact was correlated with DGGE analysis that showed the dominance of Rhodobacteraceae family during steady state conditions and disappearance of Rhizobiaceae family present in the inoculum. This particular bacterial community composition was related with the limited organic matter consumption detected in the experimental reactors, estimated in removal rates of 64.2 ± 4.8% of biodegradable chemical oxygen demand present in primary treated wastewater. In conclusion, the dominance of photoheterotroph and pigmented bacteria reduced the metabolic capability of the photobioreactor resulting in insufficient wastewater treatment with regard to discharge regulations.

Simulated impacts of relative climate change and river discharge regulation on sea ice and oceanographic conditions in the Hudson Bay Complex

In this analysis, we examine relative contributions from climate change and river discharge regulation to changes in marine conditions in the Hudson Bay Complex using a subset of five atmospheric forcing scenarios from the Coupled Model Intercomparison Project Phase 5 (CMIP5), river discharge data from the Hydrological Predictions for the Environment (HYPE) model, both naturalized (without anthropogenic intervention) and regulated (anthropogenically controlled through diversions, dams, reservoirs), and output from the Nucleus for European Modeling of the Ocean Ice-Ocean model for the 1981–2070 time frame. Investigated in particular are spatiotemporal changes in sea surface temperature, sea ice concentration and thickness, and zonal and meridional sea ice drift in response to (i) climate change through comparison of historical (1981–2010) and future (2021–2050 and 2041–2070) simulations, (ii) regulation through comparison of historical (1981–2010) naturalized and regulated simulations, and (iii) climate change and regulation combined through comparison of future (2021–2050 and 2041–2070) naturalized and regulated simulations. Also investigated is use of the diagnostic known as e-folding time spatial distribution to monitor changes in persistence in these variables in response to changing climate and regulation impacts in the Hudson Bay Complex. Results from this analysis highlight bay-wide and regional reductions in sea ice concentration and thickness in southwest and northeast Hudson Bay in response to a changing climate, and east-west asymmetry in sea ice drift response in support of past studies. Regulation is also shown to amplify or suppress the climate change signal. Specifically, regulation amplifies sea surface temperatures from April to August, suppresses sea ice loss by approximately 30% in March, contributes to enhanced sea ice drift speed by approximately 30%, and reduces meridional circulation by approximately 20% in January due to enhanced zonal drift. Results further suggest that the offshore impacts of regulation are amplified in a changing climate.

Harmonization of the water legislation of the Russian Federation

Industry is one of the main water users, since water is used in most technological and production processes. Control and treatment of industrial wastewater in order to prevent and reduce environmental pollution are among the most important areas of environmental policy. The example of wastewater discharge regulation in Germany can provide additional potential for harmonization of legislation in the Russian Federation.

Spatiotemporal change in coastal waters caused by land-based fish farm wastewater-borne nutrients: Results from Jeju Island, Korea

We investigated spatiotemporal distributions of dissolved inorganic nutrients and organic carbon (DOC) and nitrogen (DON) in coastal waters and land-based fish farm wastewater to determine effects of wastewater on seawater of Jeju Island, Korea. The nutrient concentrations in seawater were lower than in wastewater with negative correlations against salinity, indicating a terrestrial source. Wastewater-derived DOC and DON were transported offshore while wastewater-derived inorganic nutrients were effectively removed, likely via biological production, and this was closely linked to decline in N:P ratios. The correlations between DOC, DON, and colored dissolved organic matter suggest that organic matters likely originate from the fish farm wastewater. Quantitatively, the estimated wastewater-derived DOC flux was equivalent to that through submarine groundwater, which is a significant water source on the island. Our results will be able to trace contaminant sources and support assessments of seawater quality for appropriate regulation of fish farm wastewater discharge into coastal zones.

Occurrence of Giardia duodenalis in selected stations and tributary rivers of Laguna Lake, Philippines.

Fecal pollution is a major contributor to the progressive degradation of Laguna Lake, the Philippines' largest inland lake used for aquaculture, recreation, and as a source of irrigation and domestic water. Consequently, intestinal parasites may be present in this body of water, posing risks to water safety and human health. This study was able to detect the protozoan parasite, Giardia duodenalis, in three Laguna Lake stations and seven tributary rivers in a 13-month monitoring period by PCR amplification of the small subunit ribosomal RNA (SSU rRNA) gene of Giardia cysts concentrated from water samples. The pathogen was present in 37.7% of tributary samples (n = 69) and 16.7% of lake samples (n = 36). Notable frequencies of detection were observed in four tributary rivers -Bagumbayan, Taguig (66.7%); Santa Rosa, Laguna (55.6%); San Cristobal, Cabuyao, Laguna (44.4%); and Biñan, Laguna (42.9%). All test SSU rRNA gene sequences were identified as human-infective genotypes of G. duodenalis predominated by Assemblage A (94.1%). Furthermore, analysis of the glutamate dehydrogenase (gdh) gene revealed the possible presence of mixed genotypes in at least two samples. These results support the pressing need to include protozoan pathogen monitoring in Laguna Lake and its tributaries to prevent Giardia infection in humans and animals. This study also recommends microbial source tracking to identify fecal pollution sources and aid in regulation of waste discharges into the lake and its tributaries.

Synthesis of wastewater treatment process (WWTP) and supplier selection via Fuzzy Analytic Hierarchy Process (FAHP)

Wastewater treatment process (WWTP) is essential in every manufacturing company to meet stringent discharge regulations and reduce environmental impacts. The wastewater generated from manufacturing companies need to be treated in a suitably designed WWTP. However, with countless wastewater treatment technologies available in the market, WWTP technologies are usually selected based on vague assumptions and past experience. This approach to technology selection may result in high loss of investment to a company on the long run. In addition, there is a paradigm shift in the current manufacturing industrial practise towards more sustainable practices. Therefore, aspects such as carbon footprint and area footprint are important criteria to be considered during the synthesis of WWTP. In that context, this work aims to develop a decision-making tool in technology selection for the synthesis of WWTPs driven by economic and environmental incentives while meeting with local discharge regulations. As multiple optimisation objectives are involved, Fuzzy Analytic Hierarchy Process (FAHP) is adapted in this work. FAHP assigns weighting factors to criteria and alternatives based on judgements from industrial domain experts. By implementing FAHP, the synthesised final WWTP traded off at a maximum degree of satisfaction of 67.5% had reduce 244.44 USD/day of total investment cost, 134.43 kg CO2-eq/day of carbon footprint and 2 m2 of area footprint. In addition, this work had extended further the decision-making to supplier selection of wastewater treatment equipment based on the wastewater treatment technologies from the synthesised sustainable WWTP. A case study on a sago wastewater treatment process is demonstrated in this work with this proposed approach.