• 상하수도학회지
• /
• 제18권2호
• /
• pp.215-221
• /
• 2004

Effluent of wastewater treatment plant is to be disinfected to protect drinking water sources. DOF (Dissolved Ozone Flotation) was developed to meet this purpose. DOF was developed by combining DAF system with ozone. DAF system has good floating power with numerous microbubbles, and ozone has strong oxidation capability. And DOF system has good floating power and strong oxidation capability simultaneously. When DOF was applied to secondary wastewater effluent, color of 11CU in raw water which was secondary effluent was reduced to 1CU by the DOF system. Removal rate of other water quality parameters treated by DOF were also higher than that by DAF, which were proved the strength of oxidation capability of ozone. When ozone concentration of 3.3mg/l were applied in DOF system, general aerobic bacteria were reduced to 5CFU/ml from TNTC (Too many Numbers To Count). With the same ozone concentration, total coliform were not detected at all. These figures are under the numbers of drinking water regulation. These microbes were the target parameters of DOF. It was proved that DOF was very effective in disinfection of wastewater treatment plant effluent as well as in removal of color, turbidity, and T-P.

• 한국환경보건학회지
• /
• 제42권1호
• /
• pp.34-40
• /
• 2016

Objectives: This study aims to examine the concentration, diversity, and antibiotic characteristics of penicillin G resistant enterobacteria present in pharmaceutical effluent. Methods: Water sampling was performed from a pharmaceutical company in Gyeonggi-do Province, Korea in March 2015. Water samples were plated in triplicate on tryptic soy agar plates with 32 mg/L of penicillin G. Penicillin G resistant enterobacteria were selected from the effluent and were subjected to 16S rRNA analysis for penicillin G resistant species determination. Identified resistant strains were tested for resistance to various antibiotics. Results: Penicillin G resistant enterobacteria were present at 6.2% as to culturable heterotrophic bacteria. Identified penicillin G resistant enterobacteria exhibited resistance to more than 10 of the antibiotics studied. These resistant bacteria are gram negative and are closely related to pathogenic species. Conclusion: Multi-antibiotic resistant bacteria in the effluent suggest a need for disinfection and advanced oxidation processes for pharmaceutical effluents.

• 한국환경보건학회지
• /
• 제37권2호
• /
• pp.113-123
• /
• 2011

Objectives: Industrial development in Korea results in a rapid increase in the number of chemicals, some of which may be responsible for toxicity to aquatic ecosystems. In addition, the types of hazardous chemicals included in industrial effluents have gradually increased. Therefore, chemical analysis alone is not enough to assess ecological effects of toxic chemicals in wastewater. Methods: In response to new regulations as whole effluent toxicity (WET) tests for effluent discharge of 15 publicly owned treatment works (POTWs) and 25 industrial effluent treatment plants in Gyeonggi-do, which will be effective from 2011, a necessity of studies emerges that investigates toxicity levels. Results: In case of the public treatment plants, none of them had exceeded the criteria for ecotoxicity. As for individual wastewater discharge facilities, on the other hand, two types were found to exceed the criteria: pulp and paper manufacturing facilities and pharmaceutical manufacturing facilities. For the pulp and paper manufacturing facilities, monitoring results could not help determine the exact toxicant identification. However, Daphnia magna inhibition effect or death was found to leave white plums, suggesting that suspended solids treated and the polymer used in coagulant dose. In case of pharmaceutical manufacturing facilities, the general water quality parameters cannot affect Daphia magna. However, conductivity and salinity can have an effect to be 14,000 ${\mu}s/cm$, 8.1‰ by salts, respectively. Toxicity Identification Evaluation (TIE) and Toxicity Reduction Evaluation (TRE) procedures results appeared to be effective for identifying toxic compounds in $Cl^{-}$ and $SO_4^{2-}$. Conclusions: It is necessary to develop control measures for water treatment chemicals and salts used for processes such as coagulation in individual wastewater discharge facilities in order to achieve the goal to protect aquatic ecosystems in public waters.

• 한국지반환경공학회 논문집
• /
• 제16권5호
• /
• pp.27-33
• /
• 2015

정수공정 중에 응집된 망간은 슬러지 농축조에 체류하는 동안 재용출 되어 배출수의 망간 허용기준치를 초과하는 문제가 발생되고 있다. 본 연구에서는 정수공정 중에 슬러지 농축조 배출수의 pH를 조정함으로써 망간 농도에 미치는 pH의 영향에 대하여 연구하였다. 초기 pH 6.1에서는 응집된 슬러지로부터 망간이 재용출 되어 청정지역 배출 기준인 2mg/L를 초과하였으나 NaOH, KOH, CaO, $Ca(OH)_2$, $CaCO_3$ 등 알칼리 물질을 이용하여 pH를 상승시켰을 경우 망간 농도를 청정지역 배출 기준 이하로 낮출 수 있었다. 또한 알칼리성 물질로서 석회석 광산에서 선별과정 중 발생하는 폐석회석을 이용하여 정수장 슬러지의 망간 재용출을 억제할 수 있는 가능성을 확인하였다.

• 한국농공학회:학술대회논문집
• /
• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
• /
• pp.663-669
• /
• 1999

The objective of this study are to examine the feasbility of reuse treated sewage effluent ofr agricultural water, and to obtain basic data for estabilishment of rational agricultural water quality standard. From this study, it appears that reuse of treated sewage as a supplemental irrigation water could be feasible and practical alternative for ultimate sewage disposal which often causes water quality problem to the receiving water body. For full scale applicatiion, further study is recommended on the secific guidelines of major water quality components and publc health.

• 한국물환경학회지
• /
• 제29권4호
• /
• pp.568-573
• /
• 2013

In this study, we conducted whole effluent toxicity (WET) proficiency testing based on the results which $EC_{50}$ value of 3 types (A, B, C) unknown samples calculated from 32 water quality measurement agencies in Korea. WET proficiency testing was expected to their improve of analysis skill and ensure reliability of analysis results. Ultimately, it is intended to promote the reliable enforcement of WET. WET proficiency testing was evaluated using the z-score, robust z-score and the results showed that 30 participating agencies were "compliance". In addition, $EC_{50}$ values of "unknown sample A" were the normal distribution. Therefore, "unknown sample A" was considered as the most suitable standard toxicity substance.

• 한국물환경학회지
• /
• 제34권1호
• /
• pp.77-83
• /
• 2018

This paper aims to evaluate the results of toxicity testing with Daphnia magna and Vibrio fischeri on wastewater samples which might be influenced by ion imbalance. The effluents from factories were found to be more toxic with high salinity levels than those from public wastewater treatment plant (WTP) and sewage treatment plant (SWP). Clion composition was highest in the effluent, in terms of percentage, which was followed by $Na^+$, $SO_4^{2-}$ and $Ca^{2+}$. $K^+$ and $Mg^{2+}$ ion was relatively low. The sensitivity of D. magna test results was higher than V. fischeri. Among samples which were proved by V. fischeri testing to be nontoxic, the composition ratio of each ion whether toxic samples or nontoxic samples which were decided by D. magna toxicity testing, were compared. $Na^+$, $K^+$, $Ca^{2+}$, $Mg^{2+}$ ion composition ratio showed high level in nontoxic samples whereas $SO_4^{2-}$ and $Cl^-$ ion composition ratio was high in toxic samples. Accordingly, $SO_4^{2-}$ and $Cl^-$ ion seemed to be considered the ions causing toxicity in effluent. Toxicity from some categories of industries (Mining of non-metallic minerals, Manufacture of basic organic petrochemicals, Manufacture of other basic organic chemicals, Manufacture of other chemical products etc.) seemed to be influenced by salinity. The Ion concentration in influent and effluent were similar. Concentration of $Na^+$, $Cl^-$, $K^+$, $Ca^{2+}$ ions were high in influent, however $Mg^{2+}$ and $SO_4^{2-}$ ions were high in effluent.

• 상하수도학회지
• /
• 제30권6호
• /
• pp.673-682
• /
• 2016

In this study, we investigated influent and effluent water pollutants in 53 Public Sewage Treatment Works (PSTWs) where industrial wastewater or landfill leachate is combined four times for two years from 2014 to 2015. Also, we analyzed the characteristics of heavy metals and volatile organic carbons at influent and effluent of these PSTWs caused by sewage treatment combined with industrial wastewater or landfill leachate. As a result, six heavy metals such as barium, copper, iron, manganese, nickel and zinc, and four volatile organic carbons (VOCs) including phenols, di(2-)ethylhexyl phthalate (DEHP), formaldehyde and toluene were observed above detection limits in most of PSTWs. Also, it was revealed that six heavy metals such as hexavalent chromium, mercury, cadmium, chromium, nickel and selenium, and four VOCs including 1,1-dichloroethylene, vinyl chloride, naphthalene, and epichlorohydrin were observed more frequently according to precipitation. As a result of reviewing the monitoring data on "Water Quality Monitoring Networks" in lower watersheds of PSTWs, both heavy metals and VOCs were below detection limits, indicating that the effluent water had little influence on the watershed. Nevertheless for the better management of influent and effluent pollutants in PSTWs, it is necessary to establish the advanced management plans for water pollutants in PSTWs, which include a list of priority substances management, monitoring plans, and guidelines for industrial wastewater and landfill leachate combined in PSTWs.

• 한국항만학회지
• /
• 제14권3호
• /
• pp.361-371
• /
• 2000

A demand of marine outfall system has been much increased for the effective disposal of the wastewater due to population and industrial development at the coastal areas. The outfall system discharges primary or secondary treated effluent into the coastline, or at the deep water, or between these two. The discharge is carried out by constructing a pipeline on the sea bed with a diffuser or with a tunnel, risers and appropriate. The effluent, which has a density similar to that of fresh water, rises to the sea surface forming plume or jet, together with entraining the surrounding salt water and becomes very dilute. Thus there have been growing interests about plume behaviour around the outfall system. Plume or jet discharged from single-port or multi-port diffuser might cause certain impacts on coastal environment. Near field mixing characteristics of discharged water field using CORMIX model have been studied for effective outfall design various conditions on ambient current, depth, flow rate, effluent concentration, diffuser specification, port specification etc.. This kind of analysis is necessary to deal with water quality problems caused by the ocean discharge. The analyzed result was applied to the Pusan Jungang effluent outfall system plan.

• 환경영향평가
• /
• 제24권5호
• /
• pp.397-406
• /
• 2015

2013년 시행된 유역하수도정비계획에서는 유역별 수질상황을 고려하여 하수처리시설별 방류수 수질 준수농도(기준)를 별도로 적용하는 것이 가능하다. 유역의 중권역 목표기준 또는 수질오염총량관리 목표수질을 달성하기 위하여 유역하수도 제도 도입에 따라 유역 내 지역별 시설규모별 하수처리시설에 대한 방류수 수질 준수농도(안)을 설정하는 것이 필요하다. 유역환경청에서 수립하고 있는 유역하수도정비계획 수립 시 공공하수처리시설 방류수 수질 준수농도(기준)을 설정하는데 있어 II지역인 미호천유역의 경우 BOD 5 mg/L에서 3 mg/L, II III지역이 혼재되어 있는 영산강 상류유역의 경우 BOD 5~10 mg/L에서 3 mg/L로, IV지역인 안성천유역의 경우 BOD 10 mg/L에서 5 mg/L로 일률적으로 강화하도록 계획하고 있다. 이렇게 일률적으로 정하고 있는 준수농도에 대해 하수 처리기술, 유역특성을 고려한 유역하수도 공공하수처리시설의 방류수 수질 준수농도를 설정하는 방법을 제시하는 것이 필요하다. 본 연구에서는 공공하수처리시설 방류수 수질 준수농도 강화(안)을 설정할 때 이 강화된 준수농도가 공공수역 수질에 미치는 영향을 평가하여 어떤 강화(안)이 유역관리에 좀 더 효과적인지 고찰하였다.