Freshwater resources are becoming scarce and severely affected due to urbanization and industrial pollution. The per capita water supply to every Indian household is getting lesser than the ...recommended level. In this scenario, wastewater is considered as a new source of water supply for agriculture, industrial use, etc. Apart from the water laws, the government also adopted various policies and schemes to promote the reuse of treated wastewater for non-potable uses. However, the ineffective implementation of water laws and wastewater policies brought a new set of challenges. It is in this connection this paper analyses the comprehensive overview of constitutional provisions, key provisions of relevant laws, policies, rules, regulations, judicial intervention on wastewater management, and reuse in India. It also identifies implementation challenges in the enforcement of wastewater laws and byelaws in India.
The aim of the present work was to evaluate and compare the performance in the removal of pathogenic microbes in four different types of decentralized wastewater treatment systems, namely: horizontal ...flow constructed wetlands (HFCW), vertical flow constructed wetlands (VFCW), biological sand filters (BSF) and biofilters (BF). All the systems analyzed are located in Jutland, Denmark. Water sampling took place during a three months period that covered from winter to spring. Conventional microbial indicators such as Escherichia coli, total coliforms (TC), intestinal enterococci and sulphite-reducing clostridia were quantified using traditional microbiological culture methods, whereas Bacteroides spp. determination was performed by quantitative PCR (qPCR). Other water quality parameters such as dissolved oxygen, biological oxygen demand (BOD5), total suspended solids (TSS), pH, temperature, ammonium concentration and conductivity of influent and effluent water samples were also analyzed. The results showed that bacterial indicators significantly reduced in all the systems analyzed. In general, BF showed the best performance in the removal of microbes for all bacteria studied, while BSF demonstrated an improved capacity to eliminate E. coli and TC. Contrarily, VFCW seems to be more effective reducing the amount of intestinal enterococci, sulphite-reducing clostridia, and Bacteroides spp. In the present study, HFCW were the less efficient wastewater treatment system for the elimination of the evaluated pathogens. However, the performance in the removal of microbes was still significant considering that such systems were the oldest under operation (with over 20 years of continuous task).
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The world is facing a drinking water crisis. Besides continuous population growth, uneven distribution of water resources and periodic droughts have forced scientists to search for new and effective ...water treatment, remediation and recycling technologies. Therefore, there is a great need for the development of suitable, inexpensive and rapid wastewater treatment and reuse or conservation methods. This title discusses different types of wastewater treatment, remediation and recycling techniques, like adsorption, membrane filtration and reverse osmosis. It also provides guidance for the selection of the appropriate technologies or their combinations for specific applications so that one can select the exact and accurate technology without any problem. The book comprises detailed discussion on the application of various technologies for water treatment, remediation and recycling technologies and provides an update on the development in water treatment, detailed analysis of their features and economic analysis, bridging the current existing information gap. Each chapter is also documented by references and updated citations. Provides guidance for the selection of the appropriate technologies to industrialists and government authorities for the selection of exact, inexpensive technologies for specific problem solving Discusses the developments of inexpensive and rapid wastewater treatment, remediation and recycling Gives information on the application of analytical techniques, such as GC, LC, IR, and XRF for analysing and measuring water Provides an updated development in water treatment technologies, detailed analysis of their features and economic analysis, enabling to choose a problem-specific solution Completely updates the current knowledge in this field, bridging the current existing information gap.
Introduction: During the first two years of the COVID-19 pandemic, Australia implemented a series of international and interstate border restrictions. The state of Queensland experienced lim- ited ...COVID-19 transmission and relied on lockdowns to stem any emerging COVID-19 outbreaks. However, early detection of new outbreaks was difficult. In this paper, we describe the wastewater surveillance program for SARS-CoV-2 in Queensland, Australia, and report two case studies in which we aimed to assess the potential for this program to provide early warning of new community trans- mission of COVID-19. Both case studies involved clusters of localised transmission, one originating in a Brisbane suburb (Brisbane Inner West) in July-August 2021, and the other originating in Cairns, North Queensland in February-March 2021. Materials and Methods: Publicly available COVID-19 case data derived from the notifiable conditions (NoCs) registry from the Queensland Health data portal were cleaned and merged spatially with the wastewater surveillance data using statistical area 2 (SA2) codes. The positive predictive value and negative predictive value of wastewater detection for predicting the presence of COVID-19 reported cases were calculated for the two case study sites. Results: Early warnings for local transmission of SARS-CoV-2 through wastewater surveillance were noted in both the Brisbane Inner West cluster and the Cairns cluster. The positive predictive value of wastewater detection for the presence of notified cases of COVID-19 in Brisbane Inner West and Cairns were 71.4% and 50%, respectively. The negative predictive value for Brisbane Inner West and Cairns were 94.7% and 100%, respectively. Conclusions: Our findings highlight the utility of wastewater surveillance as an early warning tool in low COVID-19 transmission settings.
In this study, treatment of a local South African oil refinery effluent using a coagulation flotation process is designed using response surface methodology (RSM). A Box-Behnken design (BBD) ...implementing the RSM is applied to evaluate the effects and interactions of three operating parameters, viz., pH, coagulant dosage and flotation time, on the treatment of mineral oil wastewater (MOW). Polyacrylamide (Zetag-FS/A50), which is a water-soluble compound, is applied to enhance the adsorption mechanism and intermolecular bridging to minimise the amount of oil droplets. In addition, due to the monomeric nature and the charge density of the Zetag-FS/A50, its efficiency was evaluated to serve as an alternative coagulant for the pretreatment of the MOW. The removal of chemical oxidation demand (COD), soap oil and grease (SOG), total suspended solids (TSS) and turbidity from the MOW were used as the response variables for the coagulation flotation process. This was done with a standard dissolved air flotation jar test. The results show that the actual COD, SOG, TSS and turbidity percentage removal at optimised conditions with a coagulant dosage of 50 mg/L were 82%, 83%,70% and 83% respectively, while the predicted response was 92%, 96%, 73% and 87% for COD, SOG, TSS and turbidity, respectively. The analysis of variance (ANOVA) showed that the proposed models are significant at a 95% confidence level. A quadratic model was generated for response variables COD and SOG, while TSS and turbidity produced a linear model. The models fitted well with the experimental data with correlation coefficients (actual R2) of 0.94 for COD, 0.91 for SOG, 0.81 for TSS, and 0.75 for turbidity. The outcome of the study shows that the RSM has merit to optimise and identify the most important factor to control and the Zetag-FS/A50 coagulant has the potential to adsorb the oil droplets in order to enhance the treatment efficiency of the process.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
A series of experiments was conducted through a full-scale subsurface wastewater infiltration system (SWIS) to investigate the impact of hydraulic loading rate (HLR), organic loading rate (OLR) and ...underground temperature on nutrient removal and microbial settlement. Taking the hydraulic and treatment performance into consideration, HLR of 0.10 m3/(m2.d) was recommended with average NH3-N, TN, COD and TP removal rates of 82.6%, 81.5%, 80.9% and 90.9%, respectively. Considering treatment performance, OLR of 10.4 g BOD/(m2.d) was recommended with average NH3-N, TN, COD and TP removal rates of 88.1%, 84.8%, 86.3% and 91.3%, respectively. The number of nitrifying bacteria in each layer in the matrix decreased with increasing HLR, and the number of denitrifying bacteria increased with increasing HLR, at 0.8 and 1.0 m depths. When OLR increased, the number of bacteria and denitrifying bacteria at 0.8 and 1.0 m depths increased, and the number of nitrifying bacteria decreased. Average NH3-N, TN and COD removal rates increased with underground temperature increasing. The number of bacteria, nitrifying bacteria at 0.4 and 0.6 m depths and denitrifying bacteria at 0.8 and 1.0 m depths, increased with underground temperature increasing.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Wastewater has emerged as an alternative source of water. Since the agricultural sector remains the largest water user world-wide, it is the main potential user of treated wastewater. However, while ...there are trade-offs in using wastewater, it may be the only option in water-scarce regions. South Africa has included water reuse as a policy option; hence the aim of this study is to understand farmers’ preferences regarding water reuse frameworks for irrigation. A choice modelling approach was applied to identify the elements defining these frameworks and to quantify their relative importance amongst farmers in the agricultural hinterland of Cape Town. The findings suggest that water reuse is acceptable to farmers in the area. Furthermore, they prefer options that guarantee good quality water and low levels of restrictions on use practices. Due to low trust in water service providers, farmers are willing to pay for a privately-managed scheme for water reuse, which suggests that the management model for implementing such schemes is important.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
A series of experiments was conducted through a full-scale subsurface wastewater infiltration system (SWIS) to investigate the impact of hydraulic loading rate (HLR), organic loading rate (OLR) and ...underground temperature on nutrient removal and microbial settlement. Taking the hydraulic and treatment performance into consideration, HLR of 0.10 m3/(m2.d) was recommended with average NH3-N, TN, COD and TP removal rates of 82.6%, 81.5%, 80.9% and 90.9%, respectively. Considering treatment performance, OLR of 10.4 g BOD/(m2.d) was recommended with average NH3-N, TN, COD and TP removal rates of 88.1%, 84.8%, 86.3% and 91.3%, respectively. The number of nitrifying bacteria in each layer in the matrix decreased with increasing HLR, and the number of denitrifying bacteria increased with increasing HLR, at 0.8 and 1.0 m depths. When OLR increased, the number of bacteria and denitrifying bacteria at 0.8 and 1.0 m depths increased, and the number of nitrifying bacteria decreased. Average NH3-N, TN and COD removal rates increased with underground temperature increasing. The number of bacteria, nitrifying bacteria at 0.4 and 0.6 m depths and denitrifying bacteria at 0.8 and 1.0 m depths, increased with underground temperature increasing.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
A series of experiments was conducted through a full-scale subsurface wastewater infiltration system (SWIS) to investigate the impact of hydraulic loading rate (HLR), organic loading rate (OLR) and ...underground temperature on nutrient removal and microbial settlement. Taking the hydraulic and treatment performance into consideration, HLR of 0.10 m3/(m2.d) was recommended with average NH3-N, TN, COD and TP removal rates of 82.6%, 81.5%, 80.9% and 90.9%, respectively. Considering treatment performance, OLR of 10.4 g BOD/(m2.d) was recommended with average NH3-N, TN, COD and TP removal rates of 88.1%, 84.8%, 86.3% and 91.3%, respectively. The number of nitrifying bacteria in each layer in the matrix decreased with increasing HLR, and the number of denitrifying bacteria increased with increasing HLR, at 0.8 and 1.0 m depths. When OLR increased, the number of bacteria and denitrifying bacteria at 0.8 and 1.0 m depths increased, and the number of nitrifying bacteria decreased. Average NH3-N, TN and COD removal rates increased with underground temperature increasing. The number of bacteria, nitrifying bacteria at 0.4 and 0.6 m depths and denitrifying bacteria at 0.8 and 1.0 m depths, increased with underground temperature increasing.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
In this study, treatment of a local South African oil refinery effluent using a coagulation flotation process is designed using response surface methodology (RSM). A Box-Behnken design (BBD) ...implementing the RSM is applied to evaluate the effects and interactions of three operating parameters, viz., pH, coagulant dosage and flotation time, on the treatment of mineral oil wastewater (MOW). Polyacrylamide (Zetag-FS/A50), which is a water-soluble compound, is applied to enhance the adsorption mechanism and intermolecular bridging to minimise the amount of oil droplets. In addition, due to the monomeric nature and the charge density of the Zetag-FS/A50, its efficiency was evaluated to serve as an alternative coagulant for the pretreatment of the MOW. The removal of chemical oxidation demand (COD), soap oil and grease (SOG), total suspended solids (TSS) and turbidity from the MOW were used as the response variables for the coagulation flotation process. This was done with a standard dissolved air flotation jar test. The results show that the actual COD, SOG, TSS and turbidity percentage removal at optimised conditions with a coagulant dosage of 50 mg/L were 82%, 83%,70% and 83% respectively, while the predicted response was 92%, 96%, 73% and 87% for COD, SOG, TSS and turbidity, respectively. The analysis of variance (ANOVA) showed that the proposed models are significant at a 95% confidence level. A quadratic model was generated for response variables COD and SOG, while TSS and turbidity produced a linear model. The models fitted well with the experimental data with correlation coefficients (actual R2) of 0.94 for COD, 0.91 for SOG, 0.81 for TSS, and 0.75 for turbidity. The outcome of the study shows that the RSM has merit to optimise and identify the most important factor to control and the Zetag-FS/A50 coagulant has the potential to adsorb the oil droplets in order to enhance the treatment efficiency of the process.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
PDF
