• Journal of Bio-Environment Control
• /
• v.5 no.2
• /
• pp.145-151
• /
• 1996

The effectiveness of physiological or chemical acid - alkali solution was investigated as the method to control pH value of nutrient solution in hydroponics dynamically. Lettuces were cultivated using NH$_4$H$_2$PO$_4$ as physiological acid and NaNO$_3$ as physiological alkali or H$_2$SO$_4$ as chemical acid in dynamic control system. The pH of nutrient solution was controlled satisfactorily in the range of pH 5.5-6.5, regardless of treatments. Chemical acid changed pH of solution faster than chemical acid when supplied to the nutrient solution. Any of them did not show any harmful symptom. It is recommended that chemical acid is preferred during the growing stage and physiological acid like as NH$_4$H$_2$PO$_4$ is preferred from several days before harvest stage.

• Journal of Korean Society of Environmental Engineers
• /
• v.22 no.4
• /
• pp.661-669
• /
• 2000

This research was carried out to evaluate effect of metallic release and change of water corrosive indices by the pH and alkalinity adjustment using the SDLS (Simulated Distribution Loop System) which consist of six types of pipe loop with DCIP, PVC, PE, STS304, CP, GSP, respectively, and its effects on water quality changes which were microbes quality(SPC), residual chlorine. THMs and other parameters. And it was to propose optimal criteria of water quality control for the field application. According to the results, water control system by pH and alkalinity adjustment showed the changing of corrosive water and reducing of metallic release rate and it was not affects of THMs formation, microbes regrowth and variation of other parameters. Water quality stability and corrosion control were due to calcium carbonate precipitation film formation of pipe inner by water quality control. Therefore, corrosive water control system by pH and alkalinity adjustment can be attributed to effective water quality management in water distribution system according to water quality stability of pH and TIC(Total Inorganic Carbonate concentration) that affect the precipitation and dissolution of solids.

• Proceedings of the Korean Society for Bio-Environment Control Conference
• /
• 1996.10a
• /
• pp.64-66
• /
• 1996

수경재배에서 요구되는 최적의 배양액 pH는 5.5-6.5 이고, pH를 최적의 상태로 조절해 주는 방법으로 비료의 흡수생리를 이용하는 방법과 화학적인 산알칼리 용액을 이용하여 조절해 주는 방법이 있다. 이러한 pH 조절은 자동적으로 행해야 효과가 크며 본 실험은 흡수생리적인 면에서 산 혹은 알칼리 비료를 화학적인 산 알칼리와 비교하여 pH 조절효과의 차이를 보고자 하며 생육제어시스템 중 pH의 자동계측 및 제어를 통해서 계속적인 pH의 안정적인 수준을 유지하면서 상품성과 품질이 우수한 작물을 생산하고자 이 실험을 수행하였다. (중략)

• Journal of Korean Society of Environmental Engineers
• /
• v.33 no.8
• /
• pp.583-590
• /
• 2011

The effect of the physical parameters in the reactor (aeration depth, bubble size, and surface area) and the alkalinity of the solution on the ammonia stripping by bubbling were evaluated. When an airflow of 30 L/min was bubbled below the solution surface in the range 6-53 cm, the ammonia removal rate were observed to be the same regardless of the bubbling depths. At pH 10.0 and a temperature of $30^{\circ}C$, the average rate constant and the standard deviation were $0.178h^{-1}$ and 0.004. No appreciable changes in the ammonia removal rate were also observed with varying the bubble size and the air-contacting surface area. Alkalinity of the solution was found to affect the ammonia removal rate indirectly. This is expected because the pH of the solution would vary with dissolution of gaseous $CO_2$ by air bubbling. The real wastewaters from landfill site and domestic wastewater treatment plant were tested. In the case of domestic wastewater (pH = 7.1, alkalinity = 75 mg/L), the ammonia removal rate was poor even with the control of pH to 9.3. The raw landfill leachate (pH = 8.0, alkalinity = 6,525 mg/L), however, showed the appreciable removal rate with increasing pH during aeration. When the initial pH of the leachate was adjusted 9.4, the removal rate was significantly increased without changing the pH during aeration.

• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.4
• /
• pp.362-368
• /
• 2005

The pH, alkalinity and calcium hardness could be adjusted by $CO_2$, $Ca(OH)_2$, and $Na_2CO_3$ addition in the water treatment process for corrosion protection of the water pipes. This research was performed to investigate the effect on the variation of water quality on the unit process by addition $CO_2$, $Ca(OH)_2$, and $Na_2CO_3$ in water treatment process. Carbon dioxide and lime were added before the coagulation basin and soda ash was added after the BAC process. pH and aklainity were increased at coagulation basin then after the water qualities had sustained similiarly to BAC process. There was no effect on turbidity and DOC removal efficiency during experimental period by addition\ $CO_2$, $Ca(OH)_2$, and $Na_2CO_3$ solution was added into clear well, the last process for optimum control of CCPP and is used mainly to control pH and alkalinity. In this research, average pH, alkalinity, and calcium hardness in treated water were 8.39, 61.4 mg/L as $CaCO_3$, 59.4 mg/L as $CaCO_3$, respectively and CCPP of treated water was higher than 29.5 mg/L to BAC process water, so adjusted water was expected to prevent internal corrosion of water pipe.

• Korean Journal of Microbiology
• /
• v.38 no.3
• /
• pp.168-172
• /
• 2002

Budding yeasts maintain an effective system to regulate intracellular pH in response to environmental pH fluctuation. In a previous study we reported that SHC1 plays a role in cell growth at alkaline condition, not at acid pH. We constructed a null mutant deleted an entire open reading frame for SHC1. To test whether the retardation in cell growth was caused by the absence of intracellular pH buffering capacity, we measured intracellular pH with a pH-sensitive fluorescent dye, C.SNARE. The intracellular pH of the mutant cell was much higher than that of wild-type cells, indicating that the mutant cells lack some types of buffering capacity. We also investigated the level of $Na^＋ and K^＋$ content with atomic mass spectroscopy after alkali shock. Wild-type cell showed a higher level of intracellular K^＋$ content, whereas there was no difference in $Na^＋$ level. The result suggested that K^＋$ is more important in the regulation of intracellular pH in yeasts.

• Journal of Korean Society of Water and Wastewater
• /
• v.20 no.2
• /
• pp.215-223
• /
• 2006

The internal corrosion of water distribution systems is the main cause for the problem of the public health threat as well as water leakage in the damaged pipeline, red water, and odor and taste of the tap water. This study was examined the effect of chemicals used for pH and alkalinity control and corrosion inhibitors for producing the optimal corrosion control method. Corrosion study at different pH and alkalinity indicated that these control using alkaline chemicals was effective in corrosion rate, Fe release reduction, but examined to be increased in turbidity and corrosion-by-products(TTHMs) problems. The turbidity was slightly increased, requiring caution in controlling corrosion with $Ca(OH)_2$. At pH 9.0, TTHMs concentration is increased two times corn pared with non-control of pH. Using the pipe which had experienced 28 years of exposure, iron release was decreased with the corrosion inhibitor. Consequently, pH, Alkalinity control method using alkaline chemicals must be complemented by corrosion inhibitor application for efficient corrosion control.

• Proceedings of the Korean Environmental Sciences Society Conference
• /
• 2006.05a
• /
• pp.365-369
• /
• 2006

[ $O_3$ ]/catalyst를 이용한 고급산화공정에서 pH변화에 따른 1,4-dioxane의 화학적 분해 특성을 알아보기 위해 이 실험을 수행하였다. 초기 pH를 6, 8, 10으로 조절하여 변화를 보면 오존의 pH 완충효과에 의해 시간이 지남에 따라 알칼리와 산의 경우 중성 쪽으로 중화되는 것을 확인하였다. 그리고 시간에 따른 1,4-dioxane의 제거율은 pH 10 > pH 8 > pH 6 의 순서로 나타는 것을 보였다. 이는 오존이 산성에서는 안정하지만 알칼리성에서는 불안정함으로 인해 자기분해를 일으켜 OH라디칼의 생성을 촉진시켜 제거율이 높게 나타났다. 초기 pH를 조절한 실험, 초기 pH를 일정하게 유지한 실험에서의 50분 후의 최종 제거율은 비슷하였지만, 초기 pH를 일정하게 유지한 실험에서 제거율이 꾸준히 감소하는 것을 알 수 있었다.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.53 no.8
• /
• pp.129-135
• /
• 2016

This study is about ionic water generator filter Recently, a lot of people feel deep interest in health and drinking water. Evaluation of the stability of oxidation-reduced potential (ORP) using the filter of the alkaline water. This study utilizes the three filter of activated carbon, UF, carbon block in alkaline reduced water equipment. Passing the water to the filter is evaluated that the OPR values are stability in accordance with the change of the volume in the bucket. Alkaline reduced water equipment is a system that has the function of making the water reduction. This system is the values of the human body beneficial minerals and ORP are made in the functional water has a very low value than general water. Which has passed through the filter the water in the water negative ions and positive ions through the electrolytic. After electrolysis, the cathode side by water, including $Ca^+$, $K^+$, $Mg^+$, $Na^+$ water gets Alkaline Reduced Water containing the minerals beneficial to the human body. A positive electrode side is made of the organic materials that have an anion such as chlorine (Cl), phosphorus (P), sulfur(S). This experiment uses the Alkaline Reduced Water to adjust the magnitude of the voltage of the electrolysis in the Alkaline Reduced Water. That is 1st step(pH8) 2nd step (pH8.5) 3th step (pH9), 4th step (pH9.5) in the Alkaline Reduced Water and -1st step (pH6.0), -2nd step (pH5.0) used as the acidic oxidation water. When the water passes through the three filter in this system was evaluated whether the ORP values are changed and stabilized. When about 100 liters of water passing through the filter was confirmed that the ORP values are stability and evaluation.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.32 no.4
• /
• pp.567-573
• /
• 2003

Surimi yields from acid and alkaline processing of 5 fishes were compared to those from conventional processing Effect of sarcoplasmic protein and NaCl on heating gel from acid and alkaline surimi were also investigated by punch test and color. Yield of alkaline surimi was higher than that of conventional surimi. However, the breaking force, deformation and whiteness of heating gel from alkaline surimi were lower than those of heating gel from conventional surimi. The sarcoplasmic protein increased a breaking force and a deformation of gel. A breaking force was decreased, but deformation not significantly with NaCl concentration. Myosin heavy chain (MHC) and actin were greatly degraded in acid processing. Alkaline process for surimi is a valuable way of increasing the utilization of frozen and pelagic fishes, and making kamaboko-type products.