TREATMENT EFFICIENCY EVALUATION OF THREE MACROPHYTES FOR DOMESTIC WASTEWATER USING PILOT CONSTRUCTED WETLAND SYSTEM

The need to treat wastewater prior to disposal into the environment is of utmost importance. The use of constructed wetland systems (CWS) is becoming more popular due to their operational efficiency and cost-effective advantages over conventional treatment methods. However, the efficiency of CWS depends on the efficiency of their most vital component; aquatic macrophytes in reducing wastewater pollutants. Therefore, this study was aimed at investigating the treatment efficiency of water hyacinth (Eichhornia crassipes), water lettuce (Pistia stratiotes) and duckweed (Lemnar minor) using pilot CWS. It also examined the conformity of the treated effluents with National Environmental Standards and Regulations Enforcement Agency (NESREA) effluent discharge/reuse limits. All the 14 NESREA standard effluent discharge parameters were analysed. However, special attention was given to six (6) of the parameters; Total Suspended Solids (TSS), Total Phosphorus (TP), Total Nitrogen (TN), Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD) and E.coli) which were above the standard discharge limits. Four pilot CWS were built using 150L tanks for the three plants and a control reactor. Local substrates; sand and gravel were used to optimize the pilot CW reactors. Effluents samples were collected every 7 days for 3 weeks, while maintaining 80% plant population. The result of pollutant removal efficiencies showed that water hyacinth and lettuce attained optimum results at 14 days hydraulic retention time (HRT) with 99.30% and 99.35% COD and TP removal, respectively. Water hyacinth was better at reducing BOD, COD, EC, TDS, DO and TC with efficiency of 97.31, 85.04, 90.35, 89.66, 95.95 and 65.99%, respectively. Howbeit, lettuce was more efficient in removing TSS, TP and E.coli at 96.24%, 97.55% and 94.43%, respectively. While duckweed reduced more of E.coli; 94.43% and TN; 90.83%. Generally, the overall results proved that water hyacinth was more effiecient, but all the three macrophytes were efficient in domestic wastewater treatment. Also, the treated wastewater effluents passed NESREA limits, hence it is fit for discharge/or reuse purpose. This study is therefore a major contributor to SDG6 (clean water and sanitation)

Critical Temperature of the Deconfining Phase Transition in (2+1)d Georgi-Glashow Model

We find the temperature of the phase transition in the (2+1)d Georgi-Glashow model. The critical temperature is shown to depend on the gauge coupling and on the ratio of Higgs and gauge boson masses. In the BPS limit of light Higgs the previous result by Dunne, Kogan, Kovner, and Tekin is reproduced.Comment: 17 pages, 3 figures, REVTeX

A Superspace Formulation for the Master Equation

It is shown that the quantum master equation of the Field Antifield quantization method at one loop order can be translated into the requirement of a superfield structure for the action. The Pauli Villars regularization is implemented in this BRST superspace and the case of anomalous gauge theories is investigated. The quantum action, including Wess Zumino terms, shows up as one of the components of a superfield that includes the BRST anomalies in the other component. The example of W2 quantum gravity is also discussed.Comment: The constrained nature of standard BRST superfields and the importance of using Alfaro and Damgaard's collective fields in the superspace approach to avoid undefined superfield derivatives was emphasized. To appear in Phys. Rev. D. Latex file, 20 page

Further results for the two-loop Lcc vertex in the Landau gauge

In the previous paper hep-th/0604112 we calculated the first of the five planar two-loop diagrams for the Lcc vertex of the general non-Abelian Yang-Mills theory, the vertex which allows us in principle to obtain all other vertices via the Slavnov-Taylor identity. The integrand of this first diagram has a simple Lorentz structure. In this letter we present the result for the second diagram, whose integrand has a complicated Lorentz structure. The calculation is performed in the D-dimensional Euclidean position space. We initially perform one of the two integrations in the position space and then reduce the Lorentz structure to D-dimensional scalar single integrals. Some of the latter are then calculated by the uniqueness method, others by the Gegenbauer polynomial technique. The result is independent of the ultraviolet and the infrared scale. It is expressed in terms of the squares of spacetime intervals between points of the effective fields in the position space -- it includes simple powers of these intervals, as well as logarithms and polylogarithms thereof, with some of the latter appearing within the Davydychev integral J(1,1,1). Concerning the rest of diagrams, we present the result for the contributions correponding to third, fourth and fifth diagrams without giving the details of calculation. The full result for the Lcc correlator of the effective action at the planar two-loop level is written explicitly for maximally supersymmetric Yang-Mills theory.Comment: 29 pages, 1 figure, minor changes; three references added, one new paragraph in Introduction added, Note Added is extended; to appear in JHE

Improper waste disposal in Ota, Ogun State- a proposed waste segregation approach

The increasing and improper waste disposal attitude of many residents in Ota, Ogun State has continued to be a source of threat to human health and a healthy environment in this region. It has fostered an increase in environmental pollution over the years due to lack of proper and sustainable waste collection and management system. Previous studies have shown that the larger population of Ota residents have the attitude of burning wastes, dumping wastes on road sides, disposing wastes in canals and drainages during rainfall. These bad approaches are injurious to man’s health and have the potential to create further problems such as roads and drainages blockages. To this end, it becomes imperative and very urgent for the government of Ogun State to seriously intervene by making necessary facilities and enforced policies available so as to curb these wastes management issues. This paper discusses the issues of waste disposal in Ota, Ogun State and suggests a systematic approach to collect, segregate, recycle and dispose wastes. This will also be very effective with the swift intervention of the government-backed up policies

Performance assessment of local aquatic macrophytes for domestic wastewater treatment in Nigerian communities: A review

The concept of treating wastewater before disposal is a global necessity. Recent mechanisms of doing this include the use of Constructed Wetland Systems (CWS). This technique is believed to be cost-effective and simpler compared to conventional methods. The application of this system is primarily dependent on the use of plants through the phytoremediation process. There is evidence of the potential of some locally found Nigerian aquatic plants such as water lettuce, water hyacinth and duckweed to be applicable for this purpose. However, there is little information on their performance level in remediating domestic wastewater. Thus, this review paper assessed the performance of these local macrophytes for domestic wastewater treatment and the potential of contributing the same in Nigerian communities. This was done by reviewing recent literature on the role of water lettuce, water hyacinth and duckweed, their occurrence and their efficiency in minimising different wastewater contaminants. Contaminant indicators such as total solids, electrical conductivity (EC), BOD, COD, dissolved oxygen, total phosphorous, total nitrogen, and heavy metals have been reduced using these macrophytes. The review indicates that the selected macrophytes do not only have the potential for wastewater purification but high efficiencies in doing so when applied appropriately in the Nigerian communities

Healthcare Waste Management Practices in Nigeria: A Review Authors David O Olukanni, Justin D Lazarus, Emmanuel Fagbenle

In most low-income economies, healthcare waste (HCW) management, a major component of solid waste presents a serious concern. HCW being categorized as an hazardous or infectious solid wastes are unwanted products of healthcare activities that are generated during diagnosis or treatment of patients, immunization or vaccination of human beings or animals mostly during production or biological testing (Idowu et al., 2013; Olukanni et al., 2014; Chukwunonye, 2015; Awodele et al., 2016; Afolabi et al., 2018; Akpan & Olukanni, 2020). Hierarchical structure and complexity characterize HCW and healthcare facilities. The categories of HCW range from infectious, pathogenic, and sharp to genotoxic, chemical, and radioactive waste, each with a complement of various health risks. They include basically hazard prone materials such as blades, needles, and syringes, known as sharps, then non-sharps including 

BRST quantization of anomalous gauge theories

It is shown how the BRST quantization can be applied to a gauge invariant sector of theories with anomalously broken symmetries. This result is used to show that shifting the anomalies to a classically trivial sector of fields (Wess-Zumino mechanism) makes it possible to quantize the physical sector using a standard BRST procedure, as for a non anomalous theory. The trivial sector plays the role of a topological sector if the system is quantized without shifting the anomalies.Comment: 16 pages, latex, revised and enlarged version to appear in Phys.Rev.

Reliability assessment of ground granulated blast furnace slag/ cow bone ash- based geopolymer concrete

This study focused on the reliability assessment of ground-granulated blast furnace slag (GGBS) and cow bone ash (CBA) based geopolymer concrete (GPC). To produce the GPC, sodium silicate (Na2SiO3) was mixed with sodium hydroxide of 12M at a 2.5:1 ratio and used as the alkaline activator. The mechanical properties of the GPC were examined at 7, 14, 28, 56, and 90 days of ambient curing. Microstructural analyses were also carried out to investigate the microstructural properties that influence the mechanical performance of the GPC. Following these, a reliability assessment was carried out to establish the reliability of GPC using the constant failure model method. The results of the mechanical tests showed that GPC with GGBS composition that is ≥ 60% and CBA that is ≤ 40% performed better than the conventional concrete. At 28 days of curing, the GPC optimum mix attained a compressive strength of 40.13 MPa against 33.14 MPa attained by the conventional concrete. Also, the reliability analyses established that GPC mixes with GGBS composition that is ≥ 60% and CBA that is ≤ 40% are reliable up to the expected 50 years of service for structures. Hence, GPC is reliable as well as conventional concrete

Physical Unitarity for Massive Non-abelian Gauge Theories in the Landau Gauge: Stueckelberg and Higgs

We discuss the problem of unitarity for Yang-Mills theory in the Landau gauge with a mass term a la Stueckelberg. We assume that the theory (non-renormalizable) makes sense in some subtraction scheme (in particular the Slavnov-Taylor identities should be respected!) and we devote the paper to the study of the space of the unphysical modes. We find that the theory is unitary only under the hypothesis that the 1-PI two-point function of the vector mesons has no poles (at p^2=0). This normalization condition might be rather crucial in the very definition of the theory. With all these provisos the theory is unitary. The proof of unitarity is given both in a form that allows a direct transcription in terms of Feynman amplitudes (cutting rules) and in the operatorial form. The same arguments and conclusions apply verbatim to the case of non-abelian gauge theories where the mass of the vector meson is generated via Higgs mechanism. To the best of our knowledge, there is no mention in the literature on the necessary condition implied by physical unitarity.Comment: References added. 22 pages. Final version to appear in the journa