• Membrane and Water Treatment
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• v.6 no.2
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• pp.103-112
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• 2015

In India, recycling of treated effluent plays a major role in the industry. Particularly in copper industry, recycling techniques for treated effluents adopt conventional technologies which are not energy efficient and recovery of high quality process water, free flowing salts and sludge's is very low. This paper presents an overview of enhanced modern technology for treated effluents in copper industry making it more efficient with high recovery of high quality process water and free flowing salts. Life cycle cost (LCC) would be 15-20% lower than the conventional technologies. The conventional technology can be replaced with this proposed technique in the existing and upcoming copper industries.

• Corrosion Science and Technology
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• v.4 no.1
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• pp.15-18
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• 2005

Hydroxyapatite(HAp) was synthesized using the waste sludge from semiconductor process and used as an anticorrosive pigment. The water absorption of coating pigmented with anticorrosive pigment and the corrosion at interface between coating and substrate were monitored using AC impedance techniques. The anticorrosive performance of HAp was compared with those of red lead(RL) and zinc potassium chromate(ZPC), which have been known as representative anticorrosive pigments. The amount of absorbed water in ZPC- and HAp- pigmented coatings was much higher compared to that in RL-pigmented and unpigmented film. However, it seems that the water absorbed into HAp- or ZPC-pigmented film is beneficial to anticorrosive function. The anticorrosive performance of HAp is superior or at least comparable to those of ZPC and RL. The excellent anticorrosive properties of HAp can be explained by its passivating ability, caused by the reaction of the soluble component of HAp with Fe to form iron phosphate in the presence of water.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.2
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• pp.97-109
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• 2003

This study was conducted to investigate use possibility on waste water sludges of water disposal plant as raw materials of organic compost at Fertilizer Official Regulation of Fertilizer Management Law in 2002. In heavy metal contents, some water service sludges were discovered a little over than the standard levels of raw material regulated in organic compost and most of them were not reached the levels. But they were difficult for using the raw materials of organic compost owing to shortage of the organic content. It was judged that the fiber and leather sludges were much in the heavy metal contents and they couldn't use as the raw materials of organic compost. There was afraid that a little heavy metal contents of cosmetic sludge were less than the levels, but it was possible to use selectively as a raw material.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.39 no.2 s.120
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• pp.9-16
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• 2007

Biological treatment using the activated sludge method and biofilm process has been developed for paper wastewater treatment. It is known that a water treatment using biofilm process has a high efficiency be-cause a great deal of microorganism could adhere to media. It is also known that various plastics such as polyurethane and polyethylene have been used as the media. In this study polyethylene was used as a media and rice straw an additive agent to improve porous and hydrophilic properties of the media for waste water treatment. Porosity and hydrophilic characteristics of polyethylene was increased as rice straw was added to polyethylene. Paper wastewater was then treated with newly developed environment materials. Rice straw showed excellent results in waste water treatment in various media. This environmentally friendly material prepared by polyethylene and rice straw could show similar results to those of a commercial porous polyurethane foam in wastewater treatment.

• Journal of Korean Society on Water Environment
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• v.33 no.4
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• pp.387-393
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• 2017

A chemical batch tests were conducted to evaluate if microwave heating enhances phosphorous release from waste activated sludge (WAS) at pH 2.5, 5, 7, 9 and 11. Polyphosphate-accumulating organisms have a unique physiological feature, which releases intracellular polyphosphate granules when they are exposed under high temperature environments. Microwave irradiation was found to encourage large amount of phosphorus release from WAS, depending on pH and temperature conditions. Most of phosphorus was released below $59^{\circ}C$ within 30 min. A marked increase in phosphorus release was observed under alkaline or acidic conditions. However, based on control tests for phosphorus release under different pH conditions without microwave heating, the largest amount of phosphorus released by microwave irradiation was found at pH 7, followed by 5, 9, 11. On the other hand, crystallization was conducted to obtain magnesium ammonium phosphate (MAP) from phosphate released by microwave heating at pH 7. X-ray diffraction analysis confirmed that the recovered crystalline materials were MAP. MAP is an environmentally friendly fertilizer, which slowly releases ammonia and phosphorus in response to the demand of plant root. Thus, the recovered MAP as a phosphate fertilizer is fully expected to play a important role in the reduction of agricultural non-point pollution.

• Environmental Analysis Health and Toxicology
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• v.11 no.1_2
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• pp.31-39
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• 1996

Leachate from municipal solid waste (MSW) landfill, effluent from leachate treatment plant, and ground water sample from a monitoring well near landfill site were tested for an acute toxicity. Microtox toxicity test was used for testing the acute toxicity of leachate and other samples. EC$_{50}$ values which a concentration of pollutant for reducing 50% light output from luminescent bacteria, Photobacterium phosphoreum were determined to assess the toxicity of pollutants as well as the relative toxicity. In addition, characteristics of leachate were studied and compared to those of phenol and pentachlorophenol (PCP) which are typical aquatic toxic pollutants. For leachate, EC$_{50}$ for 30 min incubation was 10.8%, while for phenol and PCP, 46 ppm and 1.2 ppm, respectively. the relative toxicity of treated leachate by in situ aeration with activated sludge was reduced to more than 75% of toxicity of the untreated leachate. Microtox toxicity test was failed to figure out EC$_{50}$ values for groundwater from a monitoring well since the relative toxicity of the unconcentrated sample was too low to estimate EC$_{50}$. Addition of activated carbon to leachate was reduced the relative toxicity. The reduction Pattern of the relative toxicity of leachate by mechanical aeration was similar to that of PCP, but different from that of phenol. These findings suggest that the toxicity of leachate may come from PCP-like toxic compounds rather than phenol-like one. In conclusion, the process of aeration with activated sludge might be very important to reduce the environmental toxicity of leachate. And Microtox test could be a reasonable bioassay for screening and monitoring the environmental toxicity of leachate from municipal solid waste landfill as well as for determining the reduction efficiency of the leachate toxicity by various treatment processes in leachate treatment plant.

• Journal of the Korean Society of Groundwater Environment
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• v.3 no.1
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• pp.1-8
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• 1996

Coastal waste dump in Pohang is composed of slags and sludge of POSCO. Hydraulic parameters in the coastal waste dump are very different from those in municipal landfills and general unconsolidated or fractured aquifers. In the waste dump pumping or slug tests are not adequate for the estimation of hydraulic parameters. Time-lag and amplitude of the tidal fluctuation of groundwater table are used to determine the hydraulic parameters. Groundwater table at the groundwater observation wells is about 40 cm higher than the sea level. The contributing factors of the groundwater-rise are estimated. Vertical profile of some chemical constituents in groundwater indicates the gradual transition of the fresh groundwater at the uppermost position to the sea water at the bottom.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.4
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• pp.33-43
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• 2013

That occur in the ocean and the efficient management of marine litter on marine pollution oil spill response one step further strategies are needed. Marine pollution accidents occurred in 2011, a total of 287 and was found in runoff 369 kL, respectively compared to the previous year decreased by 13% and 39%. Average amount of marine materials during 5-years represent the oil flow of 310.5 kL (heavy fuel oil of 106.0 kL, diesel of 178.9 kL, oily bilge water of 22.3 kL, other oil of 7.7 kL) and the waste of 62.3 tons, the hazardous and noxious substances (HNS) was 510.6 kL. Marine emissions in 2011 by type of waste that a total amount of dumping 3,972 $m^3$, and livestock manure 795 $m^3$(20%), waste water 1,431 $m^3$(36%), sewage sludge 887 $m^3$(22%), wastewater sludge, 813 $m^3$(21%), manure 5 $m^3$(0.1%), other 41 $m^3$(0.9%), respectively. The concept of marine waste and needs to be more clearly defined. Integrated management of hazardous chemicals according to the incident management system should be established. To remove of coastal pollution, response officer needs korean coast response system. Like the marine pollution response, coastal pollution response systems also require step response.

• Korean Journal of Microbiology
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• v.44 no.1
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• pp.22-28
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• 2008

Cutting oils are emulsionable fluids widely used in metal working processes. Their composition is mineral oil, water, and additives (fatty acids, surfactants, biocides, etc.) generating a toxic waste after a long use. Cutting oils also affect colour, taste and odour of water, making it undesirable for domestic and industrial uses. In these days, conventional treatment methods as evaporation, membrane separation or chemical separation have major disadvantages since they generate a concentrated stream that is more harmful than the original waste. In this study, our purpose is to reduce cutting oils by using biological treatment. Eighty one strains were isolated from cutting waste oil of industrial waste water sludge under aerobic conditions. Among these strains, KS47, which removed 90.4% cutting oil in 48 hr, was obtained by screening test under aerobic conditions(pH 7, $28^{\circ}C$). KS47 was identified as Pseudomonas aeruginosa according to morphological, physiological and biochemical properties, 16S rDNA sequence, and fatty acid analysis. P. aeruginosa KS47 could utilize cutting oil as carbon source. In batch test, we obtained optimal degradation conditions(1.5 g/L cell concentration, pH 7, and temperature $30^{\circ}C$). Under the optimal conditions, 1,060 mg/L cutting oil was removed 83.7% (74.1 mg/L/hr).

• Journal of Environmental Science International
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• v.9 no.4
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• pp.325-330
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• 2000

The hydroxyapatite (HAp) for the present study was prepared by precipitation method in semiconductor fabrication and the crystallized at ambient to 95$0^{\circ}C$ for 30min in electric furnace. The ion-exchange characteristics of HAp for various heavy metal ions such as $Cd^{2+}, Cu^{2+}, Mn^{2+}, Zn^{2+}, Fe^{2+}, Pb^{2+}, Al^{3+}, and Cr^{6+}$ in aqueous solution has been investigated. The removal ratio of various metal ions for HAp were investigated with regard to reaction time, concentration of standard solution, amount of HAp and pH of solution. The order of the ions exchanged amount was as follws: $Pb^{2+}, Fe^{3+}>Cu^{2+}>Zn^{2+}>Al^{3+}>Cd^{2+}>Mn^{2+}>Cr^{6+}. The Pb^{2+}$ ion was readily removed by the Hap, even in the strongly acidic region. The maximum amount of the ion-exchange equilibrium for $Pb^{2+}$ ion was about 45 mg/gram of HAp. The HAp would seem to be possible agent for the removal of heavy metal ions in waste water by recycling of waste sludge in semiconductor fabrication.