Kesan kepekatan mangan terhadap biojerapan mangan oleh pencilan Bacillus cereus tempatan

Masalah pencemaran mangan (Mn) yang terkandung dalam air sangat bertoksik kepada hidupan kerana boleh menyebabkan pengumpulan pada gastro usus, penurunan tahap hemoglobin dalam darah, ketoksikan saraf, rasa mual, air kelihatan coklat kemerahan, dan juga paip tersumbat. Dalam ujikaji yang dijalankan, Mn yang terkandung dalam air dirawat dengan menggunakan pencilan Bacillus cereus tempatan. Biojerapan mangan dilakukan dengan menggunakan tiga kepekatan mangan iaitu 25, 40 dan 100 mg/L. Analisis yang terlibat dalam kajian ini adalah analisis ketumpatan optik (OD), pH, kepekatan mangan, biojisim dan unit pembentukan koloni (CFU). Keputusan menunjukkan OD, pH dan juga biojisim meningkat mengikut masa menggambarkan pertumbuhan bakteria. Kepekatan Mn menurun daripada 25, 40 dan 100 mg/L kepada 10.2, 18.6 dan 52.2 mg/L dengan peratus penyingkiran masing-masing sebanyak 55, 53 dan 50 % selepas 48 jam tempoh eraman. Manakala peratus pengambilan Mn oleh B.cereus menurun apabila kepekatan awal Mn ditingkatkan. Oleh yang demikian, proses biojerapan Mn oleh pencilan B.cereus tempatan dipengaruhi oleh peningkatan kepekatan awal Mn

Biological treatment of Pb and Zn using sequencing batch reactor

Effective wastewater treatment is essential to prevent water resources from being polluted. Usually, wastewater treatment can be divided into three distinct types; physical, chemical and biological treatment. This research aims to biologically treat Pb and Zn using the Sequencing Batch Reactor (SBR) system. There were four stages involved in the operation of SBR, which include; filled, react, settle and draw. The dissolved oxygen (DO) was controlled in the range of 2-5 mg/L, while the pH was maintained at the range of pH 6.5-7.5. Synthetic wastewater was used as influent with a C:N ratio of 200:40. In total, there were three HRT’s tested, which were 8, 24 and 48 hrs respectively. Additionally, the water quality parameters analysed were (chemical oxygen demand) COD, ammonium, mixed liquor suspended solid (MLSS) and heavy metal Pb and Zn in the effluent. The average percentage of COD removals in this research was 66.0% while the average heavy metal removal for Pb and Zn were 97.1% and 94.7%, respectively. Therefore, based on the three hydraulic retention times, (HRT’s), HRT 48 showed the highest performance in removing Pb and Zn

Recognition of Relevant ORP, pH, and DO Bending Points in Ammonia Removal from Drinking Water through Online BAF System

This study was undertaken to identify the relevant bending points in ORP, pH, and DO profiles in ammonia removal through online monitoring. A novelty BAF system as newl application for drinking water treatment that equipped with ORP, pH, DO NH4 + and NO3 − sensors was used. Two types of polluted drinking water strength (low and high strength) with various NH4 + concentrations and aeration flow were treated at a fixed-time reaction of 24 h. Experiments were conducted at four track studies (TS) of TS1 (NH4 += 50 mg/L, aeration = 0.3 L/min), TS2 (NH4 + = 100 mg/L, aeration = 2.0 L/min), TS3 (NH4 += 100 mg/L, no aeration) and TS4 (NH4 += 10 mg/L, aeration = 0.1 L/min). The results showed that the removal of NH4 + was more than 95% for TS1, TS2, and TS4. From the online monitoring performances, DO elbow and ammonia valley appeared in ORP and pH profiles, respectively. Similarly, new positive plateaus were observed in DO, indicating that the nitrifiers stopped to consume the DO after NH4 + was completely removed. Hence, based on the bending points, the aeration system is possible to be automatically stopped just after DO elbow and ammonia valley appears in order to save the energy consumption and to shorten the time demands for the drinking water treatment process

Statistical optimization of the phytoremediation of arsenic by ludwigia octovalvis in a pilot reed bed using response surface methodology (RSM) versus an artificial neural network (ANN)

In this study, the removal of arsenic (As) by plant, Ludwigia octovalvis, in a pilot reed bed was optimized. A Box-Behnken design was employed including a comparative analysis of both Response Surface Methodology (RSM) and an Artificial Neural Network (ANN) for the prediction of maximum arsenic removal. The predicted optimum condition using the desirability function of both models was 39 mg kg-1 for the arsenic concentration in soil, an elapsed time of 42 days (the sampling day) and an aeration rate of 0.22 L/min, with the predicted values of arsenic removal by RSM and ANN being 72.6% and 71.4%, respectively. The validation of the predicted optimum point showed an actual arsenic removal of 70.6%. This was achieved with the deviation between the validation value and the predicted values being within 3.49% (RSM) and 1.87% (ANN). The performance evaluation of the RSM and ANN models showed that ANN performs better than RSM with a higher R2 (0.97) close to 1.0 and very small Average Absolute Deviation (AAD) (0.02) and Root Mean Square Error (RMSE) (0.004) values close to zero. Both models were appropriate for the optimization of arsenic removal with ANN demonstrating significantly higher predictive and fitting ability than RSM

Phytoremediation of Nutrients and Organic Carbon from Sago Mill Effluent using Water Hyacinth (Eichhornia crassipes)

The aim of this study was to investigate the ability of floating water hyacinth (Eichhornia crassipes) to survive under selected concentrations of sago mill effluent (SME) and determine the nutrient uptake by the plant. Phytoremediation at 10, 15, and 20% (VSME/Vwater) SME concentrations by water hyacinth was conducted under greenhouse conditions for 30 d in a batch type experiment. After 30 d of phytoremediation, the removal efficiency of chemical oxygen demand, ammonia and phosphorus from SME wastewater were (86.4% to 97.2%), (91.4% to 97.3%) and (80.4 to 97.2%), respectively. The results proved the efficiency of water hyacinth to polish SME wastewater

Phytoremediation Efficiency of Water Hyacinth for Batik Textile Effluent Treatment

The present study focused on the phytoremediation efficiency of water hyacinth for the batik effluent treatment. Three operating factors were investigated such as retention times (0 to 28 days), batik effluent strength (20, 30 and 60%), and number of water hyacinth clumps (8, 10 and 12 clumps). The water hyacinth efficiencies was monitored through the measurement of dry weight, color, chemical oxygen demand (COD), total suspended solid (TSS), and pH. The highest efficiency of color and COD in the batik effluent treatment were achieved at day 7 with 83% (61 mg/L) and 89% (147 ADMI) removals, respectively. Both wastewater parameters were removed to below the Standard A for COD and Standard B for color. Meanwhile for TSS, the removal decreased as the batik effluent strength increased, where the highest removal (92%) was achieved at day 28 with 8 number of plant clumps. The pH was observed in range of 6 to 7. The results indicated that water hyacinth would be the best option for the low cost batik effluent treatment

Investigation of three pre-treatment methods prior to nanofiltration membrane for palm oil mill effluent treatment

Palm oil mill effluent (POME) treatment has developed in the last decade. Due to the characteristic and volume of POME, it needed a complete treatment to reduce the pollutant content. Three pre-treatments method, ultrafiltration, adsorption and decantation were applied prior to nanofiltration (NF) membrane. The polyethersulphone membrane, montmorillonite as the adsorbent and modern decanter was investigated in this research. Two types of NF membrane, named NF-1 and NF-ASP30 were used after pre-treatment. The removal of four important parameters were determined i.e. COD, TSS, colour and turbidity. The results showed that the adsorption and UF is better than decantation pre-treatment. The ultrafiltration and adsorption can reduce POME content more than 80% for all parameter while decantation varied between 40 and 80%. The combination of ultrafiltration and adsorption with both of NF membrane can removed almost all the parameter. But the decantation can only remove the turbidity but not for the rest of the parameters. Besides the POME content, the flux decline for both of NF membrane was also investigated. The flux of NF-1 membrane was higher than NF-ASP30 membrane but NF-ASP was more relative stable for the flux decline. Overall, NF-1 has better performance in flux decline

Biopolishing of Domestic Wastewater Using Polyvinyl Alcohol – Supported Biofilm of Bacterial Strain Bacillus velezensis Isolate JB7

Water pollution occurs due to the discharge of domestic waste mixed with residential, industrial, commercial, and agricultural wastewater. Conventional water treatment methods using aerobic/anaerobic methods can cause problems with the production of high green gases and result in the greenhouse effect. Microbial-based domestic sewage treatment technology using polyvinyl alcohol biofilm supporting media was introduced as an alternative measure to overcome this problem. The objective of the study was to determine the performance of polyvinyl alcohol beads in polishing domestic wastewater. In this study, the bacterium Bacillus velezensis isolate JB7 was used together with PVA as a raw material to treat domestic sewage wastewater more efficiently and stably. The results of the study show the effectiveness of domestic wastewater treatment in several factors such as pH value, chemical oxygen demand (COD), phosphorus, nitrate, nitrite, ammonia, and total suspended solids. In conclusion, domestic wastewater treatment methods using polyvinyl alcohol beads are seen to be effective, reducing the use of sewage waste plant construction sites and able to avoid the use of non-recyclable materials such as plastics and synthetics

Development of Malaysian Wastewater Polishing Index: Case Study on a Moving Bed Biofilm Reactor

Currently, extra treatment of secondary effluent to remove nitrogen and phosphorous may be required for its unrestricted reuse. This can be achieved by installing the wastewater polishing systems (or tertiary treatment). The wastewater polishing solutions are environmentally friendly, cheap and effective. The experiments were conducted on a pilot scale using a Moving Bed Biofilm Reactor (MBBR) with a capacity of 500 L to polish the municipal effluent from organic pollutant, undesirable nutrients and bacteria without the use of disinfectants. The major purpose was to define and apply a model for evaluating polishing of secondary effluent and implement the optimal technology for unrestricted use. Wastewater Polishing Index (WWPI) is a new tool that has been employed for rapidly evaluating of water quality improvement. It can be implemented into any surface water effluent treatment system or for reuse. WWPI can be an important tool designed for decision makers. The total average weight of six parameters (COD, BOD5, SS, Ammonia nitrogen, Total Phosphorus and Escherichia coli) are defined as the index, each one converted to sub-index which is scaled from zero to one hundred. If none of six parameters exist in the effluent WWPI, it is equal to zero, while if the parameters match the Malaysian’s effluent Standard B, It amounts to one hundred. In turn, WWPI is ninety when all six of them are equal to their corresponding Malaysian National Water Quality Standard (IV) for re-use. The index of wastewater polishing was validated and approved for the pilot MBBR study

Resistance of native bacteria isolated from activated sludge towards iron and manganese

A study was conducted to observe the resistance of native isolated bacteria towards selected heavy metals (iron; Fe and manganese; Mn) in a separate exposure. Isolated bacteria were evaluated by culturing them in nutrient broth medium that contained approximately 3 ×10⁶CFU/mL bacteria with different initial concentrations (0, 50, 100 and 200 mg/L). Result showed that a plate with bacterial growth indicated bacterial resistance, which was verified based on CFU/mL. At 0 mg/L, bacteria grew well on the plate with Fe and Mn. The bacterial number began to decrease at 50 and 100 mg/L for Fe and at 200 mg/L for Mn. Only a few colonies survived (isolate AM2) the toxicity of highFe amount; the isolated bacteria almost showed no growth along the plate. AM2, AM3 and AM4 presented resistance to Mn until 200 mg/L, but not AM6. The bacteria showed no growth at 100 and 200 mg/L. Thus, the Fe and Mn concentrations that can be applied during acclimatisation ranged from 0 mg/L to 200 mg/L with isolated AM2 and AM4 for Fe and Mn removal