Simultaneous Removal of Iron and Hexavalent Chromium Via Slow Sand Filter Inoculated With Thiobacillus ferrooxidans and Waste management

Many places have common physical, biological, and chemical hazards and heavy metals contamination in drinking water is very important to study especially near industrial areas and mining sources. Application of microbes along with other physicochemical techniques can prove to be the suitable remediation technology for the removal of metals from water. This study aimed to remove iron and hexavalent chromium from water using slow sand filters inoculated with iron-oxidizing bacteria Acidothiobacillus ferrooxidans. An experiment was performed for 37 days under controlled conditions, a water sample was prepared synthetically and another sample was collected from water filtration plant from Abbottabad city in KP Province- Pakistan and influents and effluents were tested for different parameters like pH, turbidity, hardness, total plate count, total dissolved solids, electrical conductivity and analysis of iron and hexavalent chromium in water. Acidothiobacillus ferrooxidans culture was isolated from soil using the differential iron media i.e. 9K medium and was inoculated into sand filters. At the end of the experiment, the removal efficiency of ferrous iron was about 52% and that of hexavalent chromium was 60.2%. In simultaneous treatment, it was observed that removal efficiency of iron was about 68% while that of hexavalent chromium was about 93% suggesting that slow sand filters were more effective for the removal of hexavalent chromium than iron. Hence, the designed slow sand filters were able to reduce the concentration of hexavalent chromium more efficiently than ferrous iron. And it was observed that slow sand filters can effectively remove ferrous iron and hexavalent chromium from water if they are inoculated with respective bacteria. Key,words,. Hexavalent Chromium, Iron Oxidizing, Sand Filters, Acidothiobacillus ferrooxidans, waste management.

INVESTIGATION OF INCREASING THE PHOTOCATALYTIC ACTIVITY OF TITANIUM DIOXIDE DUE TO THE USE OF TUNGSTEN (VI) OXIDE

The paper presents the results of experimental studies to determine the possibility of increasing the photocatalytic activity of titanium dioxide through the use of tungsten (VI) oxide, by testing the decomposition of rhodamine B as an organic pollutant in aqueous solutions under the influence of UV radiation, including in the visible spectrum. Industrial titanium dioxide of rutile modification and tungsten trioxide obtained by biological synthesis due to the use of the vital activity of thionic bacteria (Thiobacillus ferrooxidans) were used as photocatalysts. It was found that the dye concentration in a solution with a mixture of TiO2 and WO3 in a ratio of 1: 1 under the influence of natural solar radiation decreased by 85% after 28 days of study compared with 30% and 42% for solutions with pure WO3 and TiO2, respectively.

Immobilized Microbial Catalytic Oxidation Preparation and Application of Biopolymeric Ferric Sulfate

A novel inorganic polymer flocculant, biopolymeric ferric sulfate (BPFS), was prepared by immobilization technology of microorganisms and by oxidation of ferrous sulfate using domestic Thiobacillus ferrooxidans (T. f) under acidic condition. T. f was isolated on the agarose single-plate medium, which exhibited an unusual trait on the utilization of low concentration of the nitrogen source and phosphorus as the nutrient substance. Under the optimal conditions, the microorganism could grow and reproduce normally and maintain the strong catalytic oxidation activity to Fe2+. The immobilization of T. f on the polyurethane as the support matrix was investigated. Cycling batch operation was applied to the preparation of 40 kg/m3, 60 kg/m3, and 80 kg/m3 BPFS when the optimal conditions are pH value of 1.8, circulation flow rate of 0.28–0.30 L/h, and reaction temperature of 28 ± 1°C. When the prepared BPFS and SPFS (solid biopolymeric ferric sulfate) were used to dispose Songhua River water, the removal rate of turbidity and CODMn of BPFS was slightly better than that of SPFS. The removal efficiencies of turbidity and CODMn by BPFS could reach 93.9% and 79.7%, respectively. The result suggests that the BPFS has good flocculating activity.

Effects of cell concentration and coal pretreatment on desulfurization of cigalugur subbituminous coal using thiobacillus ferrooxidans

The use of coal is forecast to increase substantially to generate energy through combustion. Coal contains chemical substances that might pollute environment if it is not properly burnt, such as sulfur and nitrogen. Sulfur removal can be carried out by chemical, physical, or biological methods. Removal of sulfur from coal by microbial action has many advantages over physical and chemical desulfurization methods, namely (i) low capital and operating cost, (ii) low energy requirements, and (iii) removal of finely dispersed sulfur. This paper reports an experimental study investigating the effects of microbial cell concentration and pretreatment of coal on sulfur removal from Indonesian subbituminous coal using Thiobacillus ferrooxidans. The experiments were conducted under conditions that promote performance of the microorganism, i.e. temperature of 28°C and pH of 2.5. The procedure includes blending coal with Thiobacillus ferrooxidans in a laboratory scale reactor. Coal particles were sampled periodically during bio desulfurization. Its sulfur content was then measured according to ASTM D2492-90 (for pyretic sulfur) and ASTM D4239-94 (for total sulfur). Experimental findings show that sterilized coals give higher sulfur removal (49.8% for pyretic sulfur and 39.5% for total sulfur) than those non-sterilized (30.2% for pyretic sulfur and 34% for total sulfur). Furthermore, observed cell concentration and percentage of sulfur removal (for pyretic and total sulfur) decrease with initial microbial cell concentration. Keywords: coal, biodesulfurization, Thiobacillus ferrooxidans AbstrakPenggunaan batubara diramalkan akan meningkat secara pesat untuk membangkitkan energi melalui pembakaran. Batubara mengandung senyawa-senyawa yang dapat mencemari lingkungan apabila tidak dibakar secara tuntas, seperti sulfur dan nitrogen. Penghilangan sulfur dapat dilaksanakan secara kimiawi, fisik, maupun biologik. Penghilangan sulfur dari batubara melalui proses mikrobial menunjukkan banyak kelebihan dibandingkan dengan metode-metode desulfurisasi fisik dan kimiawi, yakni (i) biaya modal dan operasi yang rendah, (ii) kebutuhan energi yang rendah, dan (iii) kemampuan penghilangan sulfur yang terdispersi secara halus. Tulisan ini membahas kajian eksperimental mengenai pengaruh konsentrasi sel mikroba dan perlakuan awal batubara terhadap penghilangan sulfur dari batubara sub-bituminus Indonesia, oleh bakteri Thiobacillus ferooxidans. Percobaan dilaksanakan dalam kondisi yang mendorong kinerja bakteri, yakni temperatur sebesar 28°C dan pH sebesar 2,5. Prosedur percobaan mencakup pencampuran batubara dengan Thiobacillus ferooxidans dalam reaktor berskala laboratorium. Partikel batubara dicuplik secara berkala selama proses biodesulfurisasi. Kandungan sulfurnya kemudian diukur dengan metode ASTM D2492-90 (untuk sulfur pirit) dan ASTM D4239-94 (untuk sulfur total). Hasil percobaan menunjukkan bahwa batubara yang disterilisasi memberikan penurunan kadar sulfur terbesar (49,8% untuk sulfur pirit dan 39,5% untuk sulfur total) daripada batubara yang tidak disterilisasi (30,2% untuk sulfur pirit dan 34% untuk sulfur total). Selain itu, konsentrasi sel dan persentase penghilangan sulfur (untuk sulfur pirit dan total) berkurang dengan konsentrasi sel mikroba awal.Kata kunci: batubara, biodesulfurization, Thiobacillus ferrooxidans

Effect of heat treatment on bio-corrosion rate of steel structure (API 5L) in marine evironment

One of the cause of corrosion is the attachment of bacteria or commonly called as bio-corrosion or Microbial Influenced Corrosion (MIC). This aim of the research was to determine effect of heat treatment process on the bio-corrosion rate of API 5L steel. The treatments were namely, without heat treatment as a control, and with the heat treatment (austempering process). The austenizing process was conducted before the austempering process. All specimens without and with the heat treatment were be used on bio-corrosion test. The bio-corrosion testing was conducted with immersion corrosion test method with artificial seawater salinity of 35‰. Three of species bacteria were be used, Escherichia coli, Pseudomonas fluorescens, and Thiobacillus ferrooxidans. The result showed the corrosion rate on API 5L steel without bacteria was 2.7558 mpy, but it reached 3.4273, 3.6062 and 3.7699 mpy after addition with E. coli, P. fluorescens, and T. ferrooxidans, respectively. It was indicating that bacteria can accelerate the corrosion rate. The highest bio-corrosion rate due to T. ferrooxidans without heat treatment process was 3.7699 mpy. Meanwhile, the bio-corrosion rate due to T. ferrooxidans with austempering process was 3.5046 mpy. It was indicating that heat treatment can decrease the bio-corrosion rate.