Co-treatment of landfill leachate and municipal wastewater using the ZELIAC/zeolite constructed wetland system

Constructed wetland (CW) is a low-cost alternative technology to treat wastewater. This study was conducted to co-treat landfill leachate and municipal wastewater by using a CW system. Typha domingensis was transplanted to CW, which contains two substrate layers of adsorbents, namely, ZELIAC and zeolite. Response surface methodology and central composite design have been utilized to analyze experimental data. Contact time (h) and leachate-to-wastewater mixing ratio (%; v/v) were considered as independent variables. Colour, COD, ammonia, nickel, and cadmium contents were used as dependent variables. At optimum contact time (50.2 h) and leachate-to-wastewater mixing ratio (20.0%), removal efficiencies of colour, COD, ammonia, nickel, and cadmium contents were 90.3%, 86.7%, 99.2%, 86.0%, and 87.1%, respectively. The accumulation of Ni and Cd in the roots and shoots of T. domingensis was also monitored. Translocation factor (TF) was >1 in several runs; thus, Typha is classified as a hyper-accumulator plant

Renewable energy from biogas generated by sewage sludge: relationship between volume of sludge and volume of biogas / Aminuddin Muhamad Baki ... [et al.]

Biogas composed of methane and carbon dioxide is a by-product of anaerobic bacteria decomposition of organic waste which municipal garbage and sewage are important sources for biogas production. The methane content in the biogas enables it to be used as engine fuel and converted to heat and electricity. An experimental study that examined the relationship between organic content of sludge and methane generation as it progressed through mesophilic anaerobic digestion was completed. This case study is needed to determine organic content represented by BOD and SS in sewage, to quantify the biogas and methane generation from sewage sludge, to determine the relationship between organic content and volume of methane and also to determine the pressure of biogas and the relationship between sludge volume and volume of biogas. It was found that methane generation is potential during anaerobic digestion even with small volume of sludge. The quality of sludge for methane generation is dependent on the characteristics of sludge. Organic content characterized by Biological Oxygen Demand (BOD) and Total Suspended Solid (TSS) were measured in accordance to APHA standard methods (1998). Wastewater from two treatment plants namely, Kolej Mawar, UiTM and IWK WWTP Section 7, Shah Alam were used in this study. This study, found that higher organic content in sewage sludge will result in higher methane being generated

Gastrointestinal parasites of zoonotic importance observed in the wild, urban, and captive populations of non- human primates in Malaysia

Background: A study was undertaken to determine gastrointestinal (GI) parasites commonly found in Malaysia’s non- human primates (NHP) living in three different types of populations (wild, urban, and captive) and the basis of major GI parasites of zoonotic importance. Methods: A total of 308 samples was collected and microscopically screened from the NHP in the wild (n = 163), urban (n = 76), and captive (n = 69) populations. The samples were taken from 12 species of local NHPs. Results: At least, 44 species of GI parasites comprising of protozoans (seven species), nematodes (26 species), cestodes (five species), trematodes (five species), and pentastomida (one species) were detected. There were no significant differences for the overall prevalence and no great differences in GI parasite species among the wild, urban, and captive NHP populations. Conclusion: The most common GI parasite was Ascaris spp. (49.7%), followed by Oesophagostomum spp. (26.9%), and 31 species discovered in this study are of known public health importance

New Insights on the Evolution of the Sweet Taste Receptor of Primates Adapted to Harsh Environments

Taste perception is an essential function that provides valuable dietary and sensoryinformation, which is crucial for the survival of animals. Studies into the evolution of the sweet tastereceptor gene (TAS1R2) are scarce, especially for Bornean endemic primates such asNasalis larvatus(proboscis monkey),Pongo pygmaeus(Bornean orangutan), andHylobates muelleri(Muller’s Borneangibbon). Primates are the perfect taxa to study as they are diverse dietary feeders, comprising specialistfolivores, frugivores, gummivores, herbivores, and omnivores. We constructed phylogenetic trees oftheTAS1R2gene for 20 species of anthropoid primates using four different methods (neighbor-joining,maximum parsimony, maximum-likelihood, and Bayesian) and also established the time divergenceof the phylogeny. The phylogeny successfully separated the primates into their taxonomic groupsas well as by their dietary preferences. Of note, the reviewed time of divergence estimation for theprimate speciation pattern in this study was more recent than the previously published estimates. It isbelieved that this difference may be due to environmental changes, such as food scarcity and climate change, during the late Miocene epoch, which forced primates to change their dietary preferences.These findings provide a starting point for further investigation

Renewable energy from biogas generated by sewage sludge – relationship between sludge volume and power generated / Suzana Ramli ... [et al.]

Biogas is a product of decomposition of organic matter during the process of anaerobic digestion (AD). The main components are methane and carbon dioxide. The methane content in the biogas enables it to be used as fuel which can be converted to heat and electricity. The biogas generated by the anaerobic digesters has the potential to be redirected from the flaring facilities to renewable energy (RE) facilities. The biogas may then be used to generate electricity, which in turn can operate the sewage treatment plant (STP) itself. However, feedbacks from the sewerage industry indicated that heavy investments are needed for any RE initiatives on biogas generated by sewage sludge. In order to find the cost effective way of generating energy from biogas, fundamental relationships are necessary to enable development of prototype in the future. Thus, this paper presents a study to establish the relationship between the volume of sludge and the amount of power and energy that can be generated

Effects of oxygen concentration on microbial growth in aerated palm oil mill effluent using oxygen enriched air membrane system

Aeration is one of the most important factors in biological wastewater treatment process. Through aeration, oxygen is supplied to the bacteria to allow their respiration to proceed rapidly and satisfy the biochemical oxygen demand (BOD). This study was carried out to determine the biological growth in aerated palm oil mill effluent (POME) when subjected to aeration using air of different oxygen concentration. Pure oxygen (101% O2), diffused air (20.9% O2 ), and oxygen-enriched air (26.7% O2 ) were used to aerate the POME for three weeks continuously at a flow rate of 0.1 LPM. Oxygen enriched air was supplied by an oxygen enriched air system (OEAS). This system is able to enriched oxygen concentration of air up to 26.7% using membrane with composition consisting of 22% polysulfone, 31.8% dimethylacitemide, and 14.4% ethanol. Samples subjected to aeration with air of three different oxygen concentration were tested for several water quality parameters which include pH, temperature, BOD, chemical oxygen demand (COD), dissolved oxygen (DO), total solid (TS), total suspended solid (TSS), bacterial count, saturated dissolved oxygen (SDO) and dissolved oxygen deficit for every two days. It was found that bacteria count and BOD reduction in POME when aerated by OEAS was 13.8% and 18.3% respectively more than when it was aerated by diffused air. This shows that an increased in oxygen concentration during aeration can speed up the microbial growth and thus shortened the period of aerobic digestion process

A Study On The Performance And Morphology Of Multicomponents Hollow Fiber Ultrafiltration Membrane

Multicomponent (Polysulfone/poly(vinylpyrolidone)–K30/N,N-dimethylacetamide) hollow fiber ultrafiltration membrane was spun using dry-wet spinning method. The membrane was produced at different shear rate. Permeation properties and separation tests were examined using pure water flux and sodium chloride solution of concentration 1g/L respectively. Membrane morphology and molecular orientation were observed and directly measured using scanning electron microscopy (SEM) and plan polarized infrared spectroscopy. Positive infrared dichroism was detected only in samples of highest shear membranes. This suggests that the polymer molecules become aligned under high shear. Permeation test using pure water showed that increasing shear rate increases flux. On contrary, percentage rejection using sodium chloride solution showed a decreasing trend in rejection with the increased in shear rate. Increasing shear rate during dope extrusion through spinneret in the spinning of hollow fiber ultrafiltration membranes will apparently decrease the skin layer thickness and thus increasing the flux and also enhances the molecular orientation in the skin layer which causes high percentage rejection which was in the range of 21% to 33% for transmembrane pressure of 6 bar. The results indicate that there is a strong correlation between extrusion shear rate and the membrane morphology thus affecting the flux and rejection of hollow fiber ultrafiltration membranes

Phytoremediation of heavy metal from leachate using

Landfill leachate has many toxic substances, which may adversely affect the environmental health. The high concentration of heavy metal in landfill leachate creates complication to its removal and management. Hence this research was conducted to explore the ability of phytoremediation using Imperata cylindrica to remove Lead, Zinc and Cadmium; which is deemed to be nature friendly and sustainable. Raw landfill leachates were taken from the collection ponds at Jeram Sanitary Landfill and placed in fabricated phytoremediation system at UiTM laboratory. Heavy metal concentration of leachate from this system was monitored for 30 days. It was found that Imperata cylindrica is able to remove lead, Zinc and Cadmium from the leachate

Phytoremediation of heavy metal from leachate using imperata cylindrica

Landfill leachate has many toxic substances, which may adversely affect the environmental health. The high concentration of heavy metal in landfill leachate creates complication to its removal and management. Hence this research was conducted to explore the ability of phytoremediation using Imperata cylindrica to remove Lead, Zinc and Cadmium; which is deemed to be nature friendly and sustainable. Raw landfill leachates were taken from the collection ponds at Jeram Sanitary Landfill and placed in fabricated phytoremediation system at UiTM laboratory. Heavy metal concentration of leachate from this system was monitored for 30 days. It was found that Imperata cylindrica is able to remove lead, Zinc and Cadmium from the leachate