RAW WATER QUALITY ANALYSIS TO DISCOVER THE CAUSE OF PIPELINE SCALLING PROBLEM IN PT. X (ICE PRODUCTION COMPANY)

<span id="docs-internal-guid-36e28651-7fff-038c-0ab0-ffb60a635785"><span>PT. X is one of the ice companies in which its largest company is located in Bali, more precisely in the Pidada area, North Denpasar. Based on field observations the area is an area that has a calcareous soil structure. The water source of PT. X was extracted from the groundwater. From the field observation, it was found that the pipeline network, that connected the inlet water to water treatment system and ice production units, was severely covered by faint white scale. In order to discover the origin of this scale, water quality testing need to be carried out. From the results, it was found that the total hardness in the inlet water, taken from the groundwater tap, was 162.85 mg/l with calcium concentration of 2.15 mg/l and iron 3.83 mg/l. Water quality testing was also carried out in the water treatment unit consisting of resin softener where the total hardness surprisingly increased into 279.81 mg/l, calcium concentration was 2.96 mg/l, iron concentration was 0.55 mg/l. Even after being treated in softener resin, the total hardness increased sharply to 483 mg/l, which categorized as extreme hardness. The increase in total hardness indicates that there was a failure in the operation of the water treatment system, even it also contributed to the higher hardness and calcium concentration. This over-year’s treatment failure has been causing accumulation of hardness and calcium concentration in the compartment of both water treatment system and ice production unit that inflicts a higher hardness level in the effluent.</span></span>

DETERMINATION OF DEOXYGENATION RATE OF URBAN RIVER USING MODIFICATION METHODS FOR CITEPUS RIVER WATER, BANDUNG, INDONESIA

<span id="docs-internal-guid-9f43cecc-7fff-332e-09a3-ed0af9ff66fe"><span>River water quality modeling needs appropriate and suitable coefficients especially in application for specific river like urban river. </span><span>Aim:</span><span> This study aims to determine the value of the coefficient with a short term duration and a variable test time span. Several ways and methods of determining the rate of deoxygenation are developed according to the characteristics of the river and the environment. Modification method was applied in this research in which the test time span was unequal. The river chosen in this study is the Citepus River, Bandung, Indonesia representing an urban river in a tropical country. </span><span>Methodology and Results:</span><span> Sampling was carried out in the dry season. The laboratory analysis method used in determining the rate of deoxygenation uses the Slope Method of data from the short term incubation, which is ten days. The results showed that the Thomas Slope method's deoxygenation rate (K1) was 0.095 per day in the upstream segment, 0.917 per day in the middle segment, and 0.180 per day in the downstream segment. While the Ultimate BOD (La) value is 46.95 mg/l in the upstream segment, 38.70 mg/l in the middle segment, and 37.60 mg/l in the downstream segment. </span><span>Conclusion, significance, and impact of study:</span><span> The results of this study show that the value of the deoxygenation rate is similar to the theoretical surface water conditions. However, in the upstream segment, there is still a low deoxygenation rate value due to non-optimal activity of microorganisms. This findings will be very useful both in water quality modeling and river management.</span></span>

TEMPORAL VARIATION OF GROUNDWATER QUALITY IN SLEMAN, YOGYAKARTA, INDONESIA

<span id="docs-internal-guid-45763421-7fff-0266-2084-cf670bd943dc"><span>Groundwater quality evaluation is important to gain an insight of contamination source. It can later be utilized to review the implementation of a water resource management policy in a specific region. </span><span>Aim: </span><span>This study evaluate the short-term temporal variation of groundwater quality and its possible contamination source in Sleman, Yogyakarta. </span><span>Methodology and Results: </span><span>the statistical approach was utilized using boxplot, principle component analysis (PCA) and correlation matrices, to the data for 50 sampling sites. The data of groundwater quality are available from the local environmental authority of Environmental Agency Sleman.</span><span>The box plots revealed that groundwater quality might largely influenced by rainfall in the area. The factor loading of PCA presented that the ratio of concentration of both chloride and TDS are the most varied of all samples, and the less variable parameter is fluoride. The pair of groundwater quality parameter which had strong correlation were varied in each year, except for TDS and chloride that showed strong correlation in all three years. Nitrite had strong correlation with iron in 2017 and, nitrite also had strong correlation with both manganese and fluoride in 2019. The existence of fluoride in correlation with other parameter might give an insight of contamination from livestock wastes, where in the study area there are many poultry and cow farms, and small scale chicken slaughter industries. </span><span>Conclusion, significant and impact study: </span><span>This study gives preliminary understanding on temporal variation of groundwater quality, for further research on groundwater quality in Sleman, Yogyakarta.</span></span>

DEGRADATION OF POLYETHYLENE PLASTIC WASTE BY INDIGENOUS MICROBIAL CONSORTIUM AND FUNGI

<p dir="ltr"><span>Aim:</span><span> This research aims to determine the ability of indigenous microbial consortium in degrading Low Density Polyethylene (LDPE) plastics. The research start by preparing plastic into 1 x 1 cm</span><span><span>2</span></span><span> size which was cut mechanically because the smaller the size of the plastic, the larger the surface area. The plastic is placed in a petri dish containing Nutrient Broth (NB) media. The variations used were bacterial composition (%) 10, 50, and 75, variations in temperature (°C) 25, 30, 35, variations in acidity values (pH) 5, 7, 9, and variations in contact time (Td) 10 days. LDPE plastic degradation was analyzed by gravimetric method, Fourier Transform Infrared (FTIR) and Scanning Electron Microscope (SEM). Both types of bacteria were resistant or insensitive to the presence of plastic compounds as xenobiotic substrates because there was no inhibition zone around the plastic samples and they were able to grow on Nutrient Agar (NA) media added with plastic samples. Based on the results of gravimetric and FTIR analysis, the highest removal value was at a temperature variation of 30°C and pH 7 with a bacterial composition of 75% (v/v) which was incubated for 10 days. </span><span>Methodology and Results:</span><span>The results of the gravimetric analysis showed that the weight loss in LDPE plastic was 0.1548 gr to 0.1464 gr or 5.47%, while the FTIR analysis showed the intensity removal result was 70.67%. </span><span>Conclusion, significance, and impact of study: </span><span>These results were confirmed again using Scanning Electron Microscope (SEM) analysis which showed morphological changes on the surface of LDPE plastic samples. Changes that occur in LDPE plastic samples incubated with indigenous microbial consortium are influenced by several factors, including temperature, pH, contact time, and the presence of bacteria as biodegradators.</span></p><div><span><br /></span></div>

THE EFFECT OF ROTOR ROTATION SPEED ON DECREASED LABORATORY LIQUID WASTE POLLUTING PARAMETERS

<span id="docs-internal-guid-ee22e381-7fff-07aa-8160-5bce2ec61810"><span>aboratory wastewater is produced through laboratory activities. Laboratory wastewater can have a large impact on the environment if it is not processed before being discharged into the water body. Laboratory waste treatment can be carried out using suspended growth technology to reduce pollutant loads, especially Biological Oxygen Demand (BOD</span><span><span>5</span></span><span>) and Chemical Oxygen Demand (COD). </span><span>Aims:</span><span> This study aims to treat wastewater produced by the activity of laboratory using suspended growth technology. </span><span>Methodology and Results:</span><span> This research was conducted by finding the most efficient rotor rotation in degrading the load of BOD5 and COD pollutants. The reactor used is a Mixed Flow Reactor type reactor made of acrylic material with a thickness of 5.5 mm. The reactor is arranged into three series with the same sampling time and different rotor turns that expressed in rotors per minute (rpm). The reactor series consists of Reactor I with 50 rpm rotor rotation speed, 100 rpm Reactor II and 150 rpm Reactor III. Processing is carried out using 8 hours of detention time and variation of sampling time every 8 hours. </span><span>Conclusion, significant and impact study:</span><span> From the results of the study obtained the highest level of effectiveness of reducing pollutant load on processing using 150 rpm rotor rotation and 40 hours sampling time which is 94.6% for BOD</span><span><span>5 </span></span><span>parameters and 94.4% for COD parameters.</span></span>

HEAVY METAL POLLUTANT SORPTION IN AQUATIC ENVIRONMENT BY MICROALGAE CONSORTIUM

<span id="docs-internal-guid-d0229f1b-7fff-d768-d24f-5faaaf7907f0"><span>Industrial waste that contains heavy metal can cause environmental problem because of its toxicity, persistency and accumulation level in the environment. Biosorption process is highly influenced by temperature, pH, light, contact time, and ratio of surface area. Microalgae which possess two functional groups that are able to react on metal ion in a solution can be exploited to overcome environmental pollution due to heavy metal compound. Closed cultivation system in a photobioreactor is utilized to overcome contamination and evaporation problems on open pond system. Heavy metal analysis is conducted by utilizing Atomic Absorption Spectroscopy (AAS), Fourier Transform Infra-Red (FTIR), and Scanning Electron Microscope (SEM). This article provides information on biosorption as alternative technology to overcome heavy metal in water areas with no side effects on the environment with advantages of the absence of secondary pollutants, high level of efficiency, and relatively economic compared to physic-chemical method heavy metal removal methods</span></span>

HYBRID ANAEROBIC BAFFLED REACTOR FOR REMOVAL OF BOD AND PHOSPHATE CONCENTRATION IN DOMESTIC WASTEWATER

<span id="docs-internal-guid-e4ec4542-7fff-e572-3432-dc3c540a72ea"><span>Hybrid Anaerobic Baffled Reactor (HABR) is a development technology from the Anaerobic Baffled Reactor (ABR), which was already known as a technology that is successful in treating domestic waste. </span><span>Aims: </span><span>The objectives of these studies were to investigate the efficiency of reducing BOD and phosphate levels in HABR with zeolite (ZE) and activated carbon (AC) media. </span><span>Methodology and Results:</span><span> HABR reactor made of acrylic material with a size of 90 cm x 20 cm x 30 cm. The reactor designed has 7 compartments, with details the first 5 compartments are suspended growth microorganism reactors and the next 2 compartments are attached growth microorganism reactors. </span><span>Conclusion, significance, and impact of study:</span><span> The result of the research showed that the efficiency of reducing BOD concentration in the reactor with ZE and AC media were 59.30% and 65.12%, respectively. The final BOD concentration in the AC reactor is 30 mg/L, this value meets the domestic wastewater quality standard required by East Java Governor Regulation Number 72 of 2013 concerning Wastewater Quality Standards for Industry and/or Other Business Activities. The final BOD concentration in the ZE reactor exceeded the required quality standard with a value of 35 mg/L. The final phosphate levels of the two reactors meet the wastewater quality standards for business and/or laundry activities with a maximum phosphate concentration of 10 mg/L. The final phosphate levels in the ZE and AC reactors were 3.74 mg/L and 8.79 mg/L, respectively. The efficiency of phosphate removal in ZE and AC reactors were 70.58% and 30.87%, respectively.</span></span>