IMPACT OF INDUSTRIAL DYES ON ALGAL GROWTH

The deterioration of water quality because of industrial dye discharges is becoming an emerging environmental problem throughout the world. Dyes are directly discharged into nearby water bodies which in turn affect the aquatic ecosystem and human health. Dyes were degraded by means of biological methods. This study involves the application of two algae (Chlorella vulgaris and Spirulina) and oxidation pond in the decolourisation of dyes. The UV spectromax M3 spectrophotometer was used in reading absorbance values. Methylene blue (MB) (20 mg/l, 50 mg/l and 100mg/l), Eriochrome Black T (EBT) (20mg/l, 50mg/l and 100mg/l) and Melanoidin (100mg/l, 250mg/l and 500mg/l) at different concentrations were used for this study. Decolourisation was recorded in a 10-day experiment. In Spirulina, maximum dye removal was 92.37 percent (20mg/l) in methylene blue dye, 54.24 percent (20 mg/l) in EBT and 45.89percent (100mg/l) in melanoidin while in oxidation pond, the maximum dye removal was 91.84 percent (20mg/l) in methylene blue dye, 93.22percent (20mg/l) in EBT and 46.1 percent (100mg/l) in melanoidin and in Chlorella vulgaris, the maximum dye removal was 91.3 percent (20mg/l) in methylene blue dye, 79.25 percent (20mg/l) in EBT and 57 percent (100mg/l) in melanoidin. The dye removal was dependent on algal concentration and dye concentration. Gel puncture method was used to determine the toxicity of individual dyes on algae (Mixed sample, Scenedesmus and Lake Sample) at varying concentration of dyes.

Residual Level, Profile and Potential Ecological Risk of Organochlorine Pesticides in Subsurface Sediments from Lakeshore Backfill Site and Lakebed of an Abandoned Oxidation Pond After Desilting for 15 Years

The occurrence and distribution of 19 organochlorine pesticides (OCPs), together with microbial ester-linked fatty acid methyl ester (EL-FAME) profiles were investigated in sediments from an abandoned oxidation pond of Ya-Er lake, China, which had been heavily polluted by hexachlorocyclohexanes (HCHs) and chlorobenzenes in 1980s. Subsurface sediment samples were taken from five sediment cores along the transect running from lakeshore to lakebed. The concentration of total OCPs ranged from 29.8 to 941.8 ng g-1 dw, with a mean value of 193.3 ng g-1 dw. Hexachlorobenzene (HCB), HCHs and dichlorodiphenyl-trichloroethanes (DDTs) were the three dominant OCP classes, accounting for 26.5%-97.4%, 1.8%-51.5%, and 0.4%-15.5% of the total, respectively. Hot spots of HCB, HCHs and DDTs were detected in 0.9-2.7 m deep layers of the lakeshore, where was one of the dredged sediment backfill sites for in-situ remediation of the oxidation pond in 2002-2004. High potential risks of HCHs and HCB were still indicated. Historical industrial input (27.2%), recent agricultural input (14.7%), and persistent residuals (14.3%) were the three major identified sources of OCPs, using Absolute Principal Component Scores-Multiple Linear Regression (APCS-MLR). Redundancy analysis of microbial EL-FAME profiles and nine dominant OCPs revealed that the spatial variation in microbial community structure was significantly corresponded with the OCP composition. This is the first study highlighted the concern on historical industrial inputs of OCPs in subsurface sediments of the lakeshore disposal zone. The findings could help to distinguish the artificial backfill sediments from natural polluted sediments for optimization of further desilting plans.

Genome Sequences of Microviruses Identified in a Sample from a Sewage Treatment Oxidation Pond

Oxidation ponds are often used in the treatment of sewage as an aeration step prior to discharge. We identified 99 microvirus genomes from a sample from a sewage oxidation pond. This diverse group of microviruses expands our knowledge of bacteriophages associated with sewage oxidation pond ecosystems.

PENGELOLAAN LIMBAH CAIR PETERNAKAN SAPI DENGAN INTERVENSI OXIDATION POND UNTUK MENYELESAIKAN PERMASALAHAN BAU DAN RISIKO KONTAMINASI BADAN AIR

Air bekas operasional peternakan sapi yang tidak dikelola dengan baik dan langsung dibuang ke lingkungan dapat menimbulkan bau tidak sedap dan meningkatkan risiko kontaminasi badan air di sekitarnya. Tujuan dalam penelitian ini adalah untuk mengetahui sistem pengelolaan yang efektif dalam menyelesaikan permasalahan bau dan risiko kontaminasi badan air. Metode dalam penelitian ini meliputi perancangan sistem pengelolaan dan eksperimen pengolahan skala laboratorium yang melibatkan oxidation pond sebagai unit pengolahannya. Sistem pengelolaan limbah cair peternakan sapi terdiri dari 3 tahap, yakni pra-perlakuan, perlakuan primer, dan perlakuan sekunder, dimana terdapat unit pengolahan (oxidation pond) pada perlakuan sekunder. Air limbah diolah di dalam oxidation pond dengan variasi debit oksigen yang diinjeksikan 6 L/menit, 8 L/menit, dan 11 L/menit dengan waktu tinggal selama waktu hitung sesuai EPA/600/R-11/008 tahun 2011 (berturut-turut 0,256 hari, 0,1356 hari, 0,1096 hari), 3 hari, 7 hari, dan 14 hari dilengkapi dengan kontrol nilai potensial oksidasi-reduksi (ORP). Parameter yang diamati adalah bau, Biochemical Oxygen Demand (BOD) dan Ammonia Total (NH3-N). Dimana air limbah setelah proses pengolahan berwarna kekuningan dengan kekeruhan rendah dan tidak berbau. Sedangkan hasil uji setelah penelitian menunjukkan kadar BOD rata-rata telah memenuhi standar baku mutu. Dengan kadar BOD akhir tertinggi 152 mg/L dan terendah 98 mg/L. Sedangkan kadar Ammonia Total setelah penelitan tertinggi adalah 0,0088 mg/L dan terendah 0,00032 mg/L. Pengelolaan dengan oxidation pond sebagai unit pengolahan di dalamnya efektif mengatasi permasalahan bau dan menurunkan kadar bahan pencemar BOD dan Ammonia.

Biomass and Lipid Productivity by Two Algal Strains of Chlorella Sorokiniana Grown in Hydrolysate of Water Hyacinth

Hydrolysate prepared from water hyacinth biomass, containing a considerable amount of solubilised carbohydrate and nutrients, was utilised as a medium for the cultivation of two strains of Chlorella sorokiniana. These strains were isolated from an oxidation pond using two different media, i.e., BG-11 and Knop's media maintained at pH-9. Different light intensities, light-dark cycles, and various concentrations of external carbon sources (monosaccharides and inorganic carbon) were used to optimise the microalgal growth. It was observed that in the presence of organic carbon (glucose), biomass productivity increased significantly (~300 mgL-1day-1) as compared to that in the presence of only inorganic carbon (~100 mgL-1day-1). For the accumulation of stress products (lipids and carbohydrates), the microalgal strains were transferred to nutrient-amended media (N-amended and P-amended). The combined effects of glucose, inorganic carbon, and a 12h:12h light-dark cycle proved to be optimum for biomass productivity. For Chlorella sp. isolated from BG-11, maximum carbohydrate content (22%) was found in the P-amended medium, whereas high lipid content (17.3%) was estimated in the N-amended medium. However, for Chlorella sp. isolated from Knop's medium, both the lipid (17%) and carbohydrate accumulation (12.3%) were found maximum in the N- amended medium. Kinetic modelling of the lipid profile revealed that kinetic coefficients obtained for strain isolated from BG-11 media were statistically significant from each other.

Enhancing High-concentrated Wastewater Quality on Evaporation Rate from Five-Consecutive Oxidation Ponds as Located in Phetchaburi, Southerly Thailand

This research aimed to examine the environmental factors determining the rates of evaporation, a natural phenomenon contributing to the treatment of wastewater of 5-consecutive oxidation ponds of the King’s Royally Initiated Laem Phak Bia Environmental Research and Development Project. Data collected from the 17th of April to 30th of May 2019 by US Class A Evaporation Pan revealed that the sedimentation pond (Pond 1) has the highest rate, 7.22 mm d-1, the oxidation pond 1 (Pond 2), 5.70 mm d-1, the oxidation pond 3 (Pond 4), 5.56 mm d-1, the stabilization pond (Pond 5), mm d-1, the reference pond at 5.07 mm d-1 and the oxidation pond 2 (Pond 3), 3.59 mm d-1. Concluding the evaporation in domestic wastewater treatment plants is characterized by 1) heat generated from short and long wave radiation emitted by earth and the sun, 2) local wind profiles of the area affected the height differences of the roughness length, and 3) heat generated by the respiration and digestion process of microbial activities and other grey body contaminants. Presenting the day and night variations made for the analysis, the day evaporation was significantly higher resulted by the net radiation were accountable. Wind profile generated from the measurement of speeds and directions at two different sites at 3 and 10 m has explained for the roughness length heights over each pond as lower roughness height have cause the increased in the rates of evaporation in Pond 4 and 5 however, these process were also suppressed by high ionic bonding molecules effected suggested by the high TDS and EC values. The vertical temperature profile has conveyed the movement in the heat flux that dominated an upward flux movement in Pond 1. This is the exothermic reaction from the digestion process have suggested that extra heat has been added.

Disinfeksi Novel Coronavirus di Dalam Air Minum PDAM dan Air Limbah Untuk Fase Normal Baru

The first COVID-19 outbreak was occurred in Wuhan, December 2019. WHO has assigned the outbreak as pandemic on March 11, 2020. This article aims to review the effectiveness of chlorination in eradicating viruses (and bacteria) in drinking water and wastewater so that people have scientific information in eradication practice. Articles were obtained from scholar.google.com, National Library, textbooks. During pandemic doctors, paramedics have carried out curative efforts. People have carried out preventive efforts. A third attempt is needed, mechanical action using chlorine. Chlorine was able to inactivate viruses in objects affected by droplets. At a dose 0.2–40 mg/l and free chlorine residual 0.2–0.5 mg/l, chlorination was effective in eradicating viruses (and bacteria) in drinking water. Bacteria can be used as a host by viruses. If the bacteria die, viruses are inactive. The novel Coronavirus envelope can be destroyed by chlorine. Researchers have found genetic material of novel Coronavirus in wastewater. The SARS virus has also been found in raw wastewater and treated wastewater with disinfectant. This states, chlorination is not effective in eradicating viruses (and bacteria) in wastewater because of its abundant of faeces. Chlorination is also not effective for killing viruses (and bacteria) in the oxidation pond. Effluents always contain significant amounts of viruses (and bacteria). The genetic material of novel Coronavirus found in wastewater will be a latent danger after pandemic (new normal). Water treated by PDAM will become more important in new normal and must be provided in public and social facilities.

Influence of Solar Energy on the Physicochemical Parameters of Effluent Sludge and the Receiving Stream of an Oxidation Pond

Aim: This study was aimed at determining the physicochemical characteristics (such as pH, dissolved oxygen, biological oxygen demand, nitrogen, phosphorus, chloride, iron, lead, magnesium etc.) of the effluent sludge from a sewage oxidation pond and the receiving stream before and after exposure to solar energy. This is to gain a better understanding on how ultraviolet radiations from sunlight alters the physicochemical parameters inherent in the sludge and the stream. Methods and Results: Effluent sludge samples and water samples from the receiving stream were collected and exposed to solar energy over a twenty-day period. Physicochemical parameters were measured using standard methods. Results revealed that mean values of dissolved oxygen and pH increased whereas those of biological oxygen demand, ammonia nitrogen, chloride, phosphorus, iron, lead zinc and magnesium reduced over the period study. Conclusion: The findings from this study suggest that the addition of solar energy to the chains of processes in sewage treatment will produce effluents with minimal content of nutrients from organic matter and heavy metals and these will ultimately protect the receiving stream from contamination, thus contributing to human health protection.