Post-treatment of matured landfill leachate: Synthesis and evaluation of chitosan biomaterial based derivatives as adsorbents.

Matured landfill leachate is complex in nature, hence, a single conventional treatment unit is insufficient to remove the contaminants of the leachate to achieve the discharge standards. Furthermore, high levels of organic matter, colour compounds, and iron-based materials form a dark black/brown colour in leachate which is not removed by the biological treatment units. Hence, an Anoxic-Oxic Membrane Bioreactor coupled with a tertiary adsorption unit composed of crosslinked-protonated chitosan was tested for effective removal of the colour of the permeate. Several operational parameters such a pH, contact time, and adsorbent dosage on the adsorptive removal of colour were quantified using sorption-desorption experiments. Furthermore, the biosorbent was characterized using FTIR, SEM, XRD, BET-specific surface area, and pHZPC. Response Surface analysis confirmed the optimization of operational parameters conducted through traditional batch experiments. Langmuir isotherm model fitted with equilibrium data (R2 = 0.979) indicating a monolayer homogeneous adsorption. Kinetic data followed the Pseudo-Second-Order model (R2 = 0.9861), showing that the adsorbent material has abundant active sites. The percentage removal values show that the colour removal increases with time of contact and dosage of adsorbent, but removal is mainly influenced by the solution pH levels. The experimental results manifested a colour removal efficiency of 96 ± 3.8% obtained at optimum conditions (pH = 2, adsorbent dosage = 20 g/L, contact time = 48 h) along with an adsorption capacity of 123.8 Pt-Co/g suggesting that the studied adsorbent can be used as an environmentally friendly biosorbent in a tertiary unit for colour removal in a treatment system which is used to treat matured landfill leachate.

Imperative assessment on the current status of rubber wastewater treatment: Research development and future perspectives.

The environment has been significantly impacted by the rubber industry through the release of large quantities of wastewater during various industrial processes. Therefore, it is crucial to treat the wastewater from the rubber industry before discharging it into natural water bodies. With the understanding that alarmingly depleting freshwater sources need to be preserved for future generations, this paper reviews the status of the rubber industry and the pollution caused by them, focusing mainly on water pollution. The review pays special attention to the recent advancements in wastewater treatment techniques for rubber industry wastewater categorizing them into pre-treatment, secondary, and tertiary treatment processes while discussing the advantages and disadvantages. Through a comprehensive analysis of existing literature, it was determined that organic content and NH4+ are the most frequently focused water quality parameters, and despite some treatment methods demonstrating superior performance, many of the methods still face limitations and require further research to improve systems to handle high organic loading on the treatment systems and to implement them in industrial scale. The paper also explores the potential of utilizing untreated or treated wastewater and byproducts of wastewater treatment in contributing towards achieving several United Nations sustainable development goals (UN-SDGs); SDG 6, SDG 7, SDG 9, and SDG 12.

An international survey of 1014 hernia surgeons: outcome of GLACIER (global practice of inguinal hernia repair) study.

INTRODUCTION: The practice of inguinal hernia repair varies internationally. The global practice of inguinal hernia repair study (GLACIER) aimed to capture these variations in open, laparoscopic, and robotic inguinal hernia repair. METHODS: A questionnaire-based survey was created on a web-based platform, and the link was shared on various social media platforms, personal e-mail network of authors, and e-mails to members of the endorsed organisations, which include British Hernia Society (BHS), The Upper Gastrointestinal Surgical Society (TUGSS), and Abdominal Core Health Quality Collaborative (ACHQC). RESULTS: A total of 1014 surgeons from 81 countries completed the survey. Open and laparoscopic approaches were preferred by 43% and 47% of participants, respectively. Transabdominal pre-peritoneal repair (TAPP) was the favoured minimally invasive approach. Bilateral and recurrent hernia following previous open repair were the most common indications for a minimally invasive procedure. Ninety-eight percent of the surgeons preferred repair with a mesh, and synthetic monofilament lightweight mesh with large pores was the most common choice. Lichtenstein repair was the most favoured open mesh repair technique (90%), while Shouldice repair was the favoured non-mesh repair technique. The risk of chronic groin pain was quoted as 5% after open repair and 1% after minimally invasive repair. Only 10% of surgeons preferred to perform an open repair using local anaesthesia. CONCLUSION: This survey identified similarities and variations in practice internationally and some discrepancies in inguinal hernia repair compared to best practice guidelines, such as low rates of repair using local anaesthesia and the use of lightweight mesh for minimally invasive repair. It also identifies several key areas for future research, such as incidence, risk factors, and management of chronic groin pain after hernia surgery and the clinical and cost-effectiveness of robotic hernia surgery.

Treatment of mature landfill leachate in tropical climate using membrane bioreactors with different configurations.

This study describes the collection of landfill leachate from seven sites in different climatic zones of Sri Lanka and characterizes the landfills through the analyses of leachate quality. Membrane bioreactors (MBRs) with different configurations were employed to treat some of those leachates. An aerobic MBR (AMBR) system was operated in three Phases. In the first Phase, an AMBR alone, in the second Phase an anaerobic reactor followed by an anoxic reactor and an AMBR and in the third Phase an anoxic reactor followed by an AMBR were operated. In Phases I and II, the sludge retention time (SRT) and the hydraulic retention time (HRT) were kept at infinite (as no intentional wasting of sludge was made) and 96 h; in Phase III, the SRT was varied from 60, 30, 20 to 10 days and under each SRT, the HRT was varied from 96, 48, 24 and 12 h. The optimum operating conditions for the configuration used in Phase III was established through extensive experiments which had a SRT. The three MBR configurations removed more than 93%, 64.8% and 59% of BOD5, COD and total nitrogen respectively. They also removed large amounts of slowly biodegradable substances and nitrogenous compounds other than NH4+, NO3- and NO2-. Relationships between SRT and MLSS as well as SRT and fouling rate of membrane have been found. The study illustrates the capabilities of MBR in treating landfill leachate.

Size of Sri Lankan newborns at birth.

This prospective population-based study, involving 4,120 births at the Maternity Unit, Teaching Hospital Kandy, in the years 2008 and 2009, was undertaken to determine the mean birth weight of the newborns in the Central Province, Sri Lanka. The mean birth weight of 2,854 g was found to be equivalent with those calculated from several earlier studies. The mean differences in the birth weights of the three major ethnic communities, the Sinhala, the Tamils and the Sri Lankan Moors, were found to be not statistically significant. The gender difference of 60 g (CI 28-92) and the difference between the birth weights of the first and second born, for babies of all three communities were statistically significant, in uniform with those for white Caucasian populations. A graphical production of the mean birth weights is depicted in percentiles, with the mean birth weights of newborns in the UK superimposed on it for comparison.

Integrated mathematical model to simulate the performance of a membrane bioreactor.

Membrane bioreactor technology includes the integration of biological wastewater treatment and physical separation by membrane filtration. When analyzing the system performance, efficiency of biological processes, physical separation and membrane fouling must be taken into consideration. Over the years, mathematical modelling of wastewater treatment has evolved and is being used extensively to optimize the performance of treatment systems. A Number of attempts have been made towards the development of mathematical models for membrane bioreactors and most of these models have not considered the effect of soluble microbial products on membrane fouling. Also the effect of periodic membrane cleaning was neglected. In this study, an integrated mathematical model was developed for the membrane bioreactor. A biological model based on activated sludge processes (extended with biopolymer kinetics) and a physical model with cake layer kinetics and membrane fouling have been combined. In order to overcome the drawbacks of previous attempts of modelling, the influence of soluble microbial products and extracellular polymeric substances are considered in the model integration. Further, the physical processes of the sludge removal and membrane cleaning which have strong influence on membrane fouling are considered in the model. "AQUASIM", a computer program for the identification and simulation of aquatic systems, was used for solving the processes. Calibrated and validated model enables the prediction of the system performance and membrane fouling under different operating conditions.

Fouling of ion exchange membranes used in the electrodialysis reversal advanced water treatment: A review.

Electrodialysis self-reversal (EDR) technology has attracted in the treatment of water for domestic and industrial uses. The self-reversal consists of a frequent reversal of the direction of current between the EDR-cell electrodes to combat fouling of ion exchange membranes (IEMs). Irrespective of the EDR self-cleaning processes, the role of natural organic matter and their complexing ability with metal ions on IEMs fouling is partially understood. The objective of this review is to identify the research gaps present in the elucidation of IEM fouling routes. The common IEMs' foulants are identified, and several fouling mechanisms are briefly discussed. The effectiveness of self-cleaning mechanisms to reduce IEMs fouling is also be discussed. Dissolved organic carbon (DOC) possesses high chelation which forms metal complexes with di and trivalent cations found in water. The role of ternary complexes, e.g. M2+/3+-DOC and membrane surface, on membrane fouling via surface bridging, are also addressed. Finally, mitigation methods of IEMs membrane fouling are also discussed.

A marsupial, Trichosurus vulpecula, DDX4/VASAGene (TvDDX4) of the DEAD box protein family: molecular conservation and germline expression.

The DDX4/VASA gene plays an important role in germ cell development in animals. We cloned and characterized a marsupial DDX4/VASA homolog (TvDDX4, 2,769 bps) from the possum and examined its expression in adult tissues at mRNA and protein levels. The isolated cDNA had a deduced 704 amino acid residues with significant homology to DDX4 from other animals, including mouse (86%) and human (87%). The DDX4 transcript was detected in the ovary and testis, and was undetectable in somatic tissues. The recombinant possum DDX4 protein (TvDDX4) was successfully produced in a bacterial expression system and used in polyclonal antibody generation. The recombinant TvDDX4 was detected by antibody against human DDX4 and mouse antibody against TvDDX4, but native possum TvDDX4 was only recognized by the possum antibody in the ovary and testis. Our results suggest a structural and functional conservation of DDX4 in marsupials and in mammals in the therian branches.

Early cleavage to formation of the unilaminar blastocyst in the marsupial Antechinus stuartii: ultrastructure.

The development of Antechinus stuartii from the 2-cell stage to the blastocyst stage in vivo was examined by routine transmission electron microscopy. The 2-8-cell stages had a similar organization of organelles, whereas the 16- to 32-cell stages had pluriblast cells and trophoblast cells forming an epithelium closely apposed to the zona pellucida. Specialized cell-zona plugs were formed at the 8-cell stage, and primitive cell junctions appeared in later conceptuses. The cytoplasmic organelles included mitochondria, lysosomes, aggregates of smooth endoplasmic reticulum, lipid and protein yolk bodies and fibrillar arrays, possibly contractile in function. Nuclei had uniformly-dispersed dense chromatin. Nucleoli of 2-4-cell conceptuses were dense, compact and fibrillar, and those of 8-cell conceptuses and later conceptuses were finely granular and became progressively reticulated. The embryonic genome is probably not switched on before the 8-cell stage. Sperm tails were detected in cells in several early conceptuses. The yolk mass had the same organelles as cells. Centrioles were discovered for the first time in marsupial conceptuses. These were prominently situated at a spindle pole in a 32-cell blastomere and were associated with a nucleus and sperm tail at the 4-cell stage. It is very likely that the paternal centrosome is inherited at fertilization and perpetuated in Antechinus embryos during cleavage.

A low-energy intensive electrochemical system for the eradication of Escherichia coli from ballast water: process development, disinfection chemistry, and kinetics modeling.

The invasion of biological organisms via ballast water has created threats to the environment and human health. In this study, a cost-effective electrochemical disinfection reactor was developed to inactivate Escherichia coli, one of the IMO-regulated indicator microbes, in simulated ballast water. The complete inactivation of E. coli could be achieved within a very short time (150, 120, or 60 s) with an energy consumption as low as 0.0090, 0.0074 or 0.0035 kWh/m(3) for ballast water containing E. coli at concentrations of 10(8), 10(7) and 10(6) CFU/100 mL, respectively. Electrochemical chlorination was the major disinfection mechanism in chloride-abundant electrolytes, whereas oxidants such as ozone and free radicals contributed to 20% of the disinfection efficiency in chloride-free electrolytes. Moreover, a disinfection kinetics model was successfully developed to describe the inactivation of E. coli.

Electrochemical disinfection for ballast water management: technology development and risk assessment.

Ballast water is essential in maintaining the balance and structural integrity of ships during voyage. However, it has created biological invasion threats to the ocean environment. An innovative electrochemical technology was developed in this study. The microorganisms regulated by the International Maritime Organization (D2) were used as the target organisms. It was found that the required energy to meet the D2 was below 0.006 kWh/m3. The size of disinfector (m3) was about 0.5% of treatment flow rate (m3/h). The complete disappearance of chlorine in seawater was achieved after three days. The ballast tank corrosion was not worsened due to the application of technology. The ecotoxicity studies showed no toxic effect on fish, invertebrate, and algae. Finally, the environmental risk assessment showed the treated water did not pose threats to the environment. It can therefore be concluded that the technology provides a cost-effective and environmental friendly solution to ballast water management.

The field trial of the mental disorders section of ICD-10 designed for primary care (ICD10-PHC) in England.

This study reports the English field trial of a primary health care version of the section of ICD-10 dealing with mental disorders. The classification gives guidance on both diagnosis and management of 24 common disorders. Fifty doctors collaborated with the study, in four different locations, and 40 completed all their assessments. The new classification has been well received, and there was an increase in the participants' interest in mental disorders and in their confidence in making diagnoses. Use of the depression card increased the range of symptoms considered when making a diagnosis of depression, increased the threshold for prescription of antidepressants, and added to the management suggested for depressive illnesses. The many constructive comments made about the cards will be taken into account by WHO when the classification is revised later in 1995.