Correlations between silt density index,turbidity and oxidation-reduction potential parameters in seawater reverse osmosis desalination

The reverse osmosis method is one of the most widely used methods of seawater desalination at present.Hydrophilic and desalting membranes in reverse osmosis systems are highly susceptible to the input pollutants.Various contaminants,including suspended organic and inorganic matter,result in membrane fouling and membrane degradation.Fundamental parameters such as the turbidity,the amount of chlorine injection,and silt density index (SDI) are the most predominant parameters of fouling control in the membranes.In this study,the operation system included a water intake unit,a pretreatment system,and an RO system.The pretreatment system encompassed a clarifier,a gravity sand filter,pressurized sand filters,and a cartridge filter.The correlation between the amount of chlorine injection in terms of the oxidation-reduction potential (ORP) and the SDI value of the input water was investigated at a specified site next to the Persian Gulf.The results showed that,at certain intervals of inlet turbidity,injection of a certain amount of chlorine into the raw water has a distinct effect on the decrease of SDI.

Principles of Technology for Bottling Medicinal Mineral Waters of Sairme Using the Example of Source №3a

Sairme mineral water, one of the famous mineral waters in Georgia, is renowned for its exceptional healing properties. The distinctiveness and therapeutic benefits of the naturally sourced mineral water, known as “Sairme”, stem from its rich array of microelements, notably including iron and manganese. Since 1948, the bottling of Sairme mineral water has been a prominent activity. Named after the Sairme deposit, this mineral water is packaged in various formats to cater to diverse consumer preferences. The bottling process involves transporting the mineral water from wells to the bottling plant through pipelines. Prior to bottling, the mineral water undergoes meticulous processing stages in adherence to current Georgian and international regulations. This process ensures that the concentration of trace elements in the bottled water is minimized, maintaining its purity and quality. Given the importance of preserving the microelements present in bottled mineral water, our research is dedicated to optimizing the technological process. Our objective is to safeguard the valuable microelements while ensuring the highest standards of quality and safety in the final product.

Multi-center evaluation of oxidation-reduction potential by the MiOXSYS in males with abnormal semen

According to the World Health Organization(WHO),oxidative stress(OS)is a significant contributor to male infertility.SeminalOS can be measured by a number of assays,all of which are either costly or time sensitive and/or require large semen volume andcomplex instrumentation.One less expensive alternative is to quantify the oxidation-reduction potential(ORP)with the MiOXSYS.In this international multi-center study,we assessed whether ORP levels measured by the MiOXSYS could distinguish semensamples that fall within the 2010 WHO normal reference values from those that do not.Semen samples were collected from 2092patients in 9 countries;ORP was normalized to sperm concentration(mV/10^6 sperm/ml).Only those samples with a concentration>1×10^6 sperm ml1 were in eluded.The results showed that 199 samples fell within the WHO no rmal refere nee range while theremaining 1893 samples did not meet one or more of the criteria.ORP was negatively correlated with all semen parameters(P <0.01)except volume.The area under the curve for ORP was 0.765.The ORP cut-off value(1.34 mV/10^6 sperm/ml)was able todifferentiate specimens with abnormal semen parameters with 98.1%sensitivity,40.6%specificity,94.7%positive predictivevalue(PPV)and 66.6%negative predictive value(NPV).When used as an adjunct to traditional semen analysis,ORP levels mayhelp identify altered functional status of spermatozoa caused by OS in cases of idiopathic male infertility and in male partners ofcouples sufferi ng recurre nt pregna ncy loss,and thereby directi ng these men to relevant medical therapies and lifestyle modificati ons.

Assessing high resolution oxidation-reduction potential and soluble reactive phosphorus variation across vertical sediments and water layers in Xinghu Lake:A novel laboratory approach

To understand the transfer process of soluble reactive phosphorus （SRP） on the lake sediment-water interface in a mesotrophic shallow lake in South China, the SRP concentrations and the oxidation-reduction potential （ORP） across the sediment-water interfaces were continually monitored. Sediment samples were collected from Xinghu Lake in Guangdong Province. The ORP dynamics at different layers of overlying water was similar for six experimental systems, whereas those in porewater were significantly different. The ORP in overlying water was 200-300 mV higher than those in sediments. The oxygen penetration depth ranged from 2 to 10 mm in Xiannu Lake sediments. The variation amplitudes of ORP increased with sediment depth, but the mean ORP values were all about 218 mV. The SRP concentrations in porewater maintained at a low level of about 0.049 mg/L because of high atom ratio of total iron and total manganese to total phosphorus. The SRP concentrations and variation amplitudes in porewater increased with sediment depth. The SRP in overlying water mainly originated from S RP transference of the porewater of middle and bottom sediments （3-15 cm）. The ORP variation and SRP transfer in porewater played important roles in changing SRP concentrations. A distinct SRP concentration gradient appeared in overlying water when intense exchange occurred at the sediment-water interface; therefore, it was necessary to monitor the SRP concentration profiles to accurately estimate the internal loading.

大鹏澳网箱养殖区沉积物硫酸盐还原菌(SRB)及其与环境因子关系的初步研究

实验采用MPN法测定了大鹏澳网箱养殖区沉积物中硫酸盐还原菌(SRB)的含量,布设的5个站位SRB检出率达100%,SRB平面分布特征是鱼类网箱区>对照区>浮筏贝类区;垂直分布特征为1cm层>5cm层>10cm层,SRB数量是由上向下逐渐减少。探讨了SRB含量与相应沉积物样品中的硫化物含量、氧化还原电位、pH等环境因子的关系。结果表明,沉积物中SRB数量与硫化物含量呈显著性正相关(R=0.96,P<0.05),与氧化还原电位(OPR)呈极显著性负相关(R=-0.97,P<0.01),与pH之间不具有显著性关系。

Applying real-time control to enhance the performance of nitrogen removal in CAST system

A bench-scale reactor（72 L） red with domestic sewage, was operated more than 3 months with three operation modes： traditional mode, modified mode and real-time control mode, so as to evaluate effects of the operation mode on the system performance and to develop a feasible control strategy. Results obtained from fixed-time control study indicate that the variations of the pH and oxidation-reduction potential（ORP） profiles can represent dynamic characteristics of system and the cycle sequences can be controlled and optimized by the control points on the pH and ORP profiles. A control strategy was, therefore, developed and applied to real-time control mode. Compared with traditional mode, the total nitrogen（TN） removal can be increased by approximately 16% in modified mode and a mean TN removal of 92% was achieved in real-time control mode. Moreover, approximately 12.5% aeration energy was saved in real- time control mode. The result of this study shows that the performance of nitrogen removal was enhanced in modified operation mode. Moreover, the real-time control made it possible to optimize process operation and save aeration energy.

Influence of packing media on nitrogen removal in a subsurface infiltration system

Influence of packing media on nitrogen removal in a subsurface infiltration system was studied. System A was filled with loamy soil and system B was filled with mixed soil of 75% red clay with 25% cinder. Both systems were fed with sewage at the same hydraulic loading of 2 cm/d at continuous operation mode. The same excellent removal performances of COD and T-P could be achieved in both infiltration systems with removal rates about 85% and 98%, respectively. In system A, NH +_4-N removal rate was as high as 96.5% and T-N removal rate was relatively much lower as 55.7%. And in system B, NH +_4-N removal rate was as low as 75.4% and T-N removal rate was relatively much higher as 75.5%. The difference was attributed to different soil oxidation-reduction condition that was greatly influenced by soil texture in subsurface infiltration system. Loamy soil led to oxidative condition that was favorable to nitrification and disadvantageous to denitrification. The results were just adverse to the system filled with clay. Intermittent operation was adopted to improve nitrogen removal in system B. NH +_4-N removal rate could be increased to about 95% and T-N removal rate could be increased to about 90% at intermittent operation mode in system B. Analysis of nitrogen removal mechanisms indicated that nitrification-denitrification was the primary nitrogen removal path in subsurface infiltration system and crop uptake was another important nitrogen removal way. It was the key to improve the total N removal performance that a suitable packing soil was available to present favorable oxidation-reduction condition for simultaneous nitrification and denitrification.

Effect of Dissolved Oxygen on Operation of EGSB

An expanded granular sludge bed (EGSB) reactor was adopted to study the dissolved oxygen (DO) effect on the operation. With the chemical oxygen demand (COD) 800-1 800 mg/L, pH 6.0-7.3, volume loading rate (VLR) 5.4-11.5 kg COD/(m3·d), the operational behaviors of EGSB reactor was researched. And the max DO concentration which influenced steady operation of EGSB reactor was determined by contrasting the changes due to different concentrations of the influent DO. With the COD 1 200-2 000 mg/L, VLR 7.2-12.0 kg COD/(m3·d), the operational characteristic of EGSB reactor was researched by aerating the recycle effluent. The results was: when the DO concentration of influent was under 3.0 mg/L, the removal efficiency of COD was 82%-90% and the operation of the EGSB reactor was steady; when the DO concentration of influent was over 3.0 mg/L, the oxidation-reduction potential (ORP) fluctuated greatly and the operation of the EGSB reactor was instable; the acidified wastewater of saccharide whose pH value was 5.1-6.5 could be treated by aerating the recycle effluent and the efficiency of COD was up to 85%-92%.

Low Doses of Ionized Radiation and Hypomagnetic Field Alter Redox Properties of Water and Physiological Characteristics of Seeds of the Highest Plants

The influence of a 40-fold attenuated geomagnetic field and its combined action with low doses of α- and γ-irradiation on the physiological characteristics of seeds of the highest plants and redox properties of water was investigated. It established the reduction of seed germination both under direct and indirect effects due to water action of attenuated geomagnetic field. A negative effect of hypomagnetic field on grown characteristics of seeds under indirect effect via water was decreased by the low doses of γ-irradiation, and was increased by low doses of α-irradiation, i.e. ionized radiation was the dominant factor in their combined action. It was revealed the increasing of the value of the oxidation-reduction potential of water under the influence of low-intensive α-ir-radiation (239Pu), γ-irradiation (137Cs) and also that the magnetic induction attenuated pointing to a natural decline. The increasing of the oxidation-reduction potential value testifies about “the regular decreasing of internal energy of water molecules” and the increasing of its oxidative properties, which, in our opinion, is caused the inhibition of the germination of seeds. It is supposed that namely water is the main component in the effects of studying factors on bio-objects, which acts due to the alterations of the properties and structural content of water.

Novel coprecipitation-oxidation method for recovering iron from steel waste pickling liquor

Waste pickling liquors （WPLs） containing high concentrations of iron and acid are hazardous waste products from the steel pickling processes. A novel combined coprecipitation-oxidation method for iron recovery by Fe304 nanoparhcle＇ production from the WPLs was developed in this study. 2＋All oxidation-reduction potential monitoring method was developed for real-time control of the Fe2＋/Fe3＋ molar ratio. The key coprecipitation-oxidation parameters were determined using the orthogonal experimental design method. The use of promoters greatly improved the Fe3O4 nanoparticle crystallinity, size, magnetization, and dispersion. X-ray diffraction patterns showed that the produced Fe3O4. nanoparticles were single phase. The Fe3O4 nan oparticles were approximately spherical and slightly aggtomerated. Vibrating sample magnetometry showed that the Fe3O4 nanopahicles produced from the WPLs had good magnetic properties, with a saturation magnetization of 80.206 emu. g-1 and a remanence of 10.500 emu. g-1. The results show that this novel coprecipitation-oxidation method has great potential for recycling iron in WPLs.

On-line controlling system for nitrogen and phosphorus removal of municipal wastewater in a sequencing batch reactor (SBR)

The objectives of this study were to establish an on-line controlling system for nitrogen and phosphorus removal synchronously of municipal wastewater in a sequencing batch reactor(SBR).The SBR for municipal wastewater treatment was operated in sequences:filling,anaerobic,oxic,anoxic,oxic,settling and discharge.The reactor was equipped with on-line monitoring sensors for dissolved oxygen(DO),oxidation-reduction potential(ORP)and pH.The variation of DO,ORP and pH is relevant to each phase of biological process for nitrogen and phosphorus removal in this SBR.The characteristic points of DO,ORP and pH can be used to judge and control the stages of process that include:phosphate release by the turning points of ORP and pH;nitrification by the ammonia valley of pH and ammonia elbows of DO and ORP;denitrification by the nitrate knee of ORP and nitrate apex of pH;phosphate uptake by the turning point of pH;and residual organic carbon oxida-tion by the carbon elbows of DO and ORP.The controlling system can operate automatically for nitrogen and phosphorus efficiently removal.

Biochars reduce irrigation water sodium adsorption ratio

Irrigation water quality plays a vital role in sustaining crop productivity and feeding a growing world population.In many countries,continued agricultural water reuse can lead to greater water-soluble salt concentrations,and in particular Na;finding means by which irrigation water Na,and thus sodium adsorption ratios(SAR),can be reduced would reduce the rate at which soil sodification occurs.Four biochars,containing a variety of organic functional groups and electrochemistries,were examined for their potential to sorb and remove Na from simulated irrigation water,and subsequently reduce water SAR.Two batch experiments examined the role that wheat straw biochar,lodgepole pine biochar,Kentucky bluegrass biochar,and hemp biochar played in terms of sorbing sodium over time or application rate.Of the four biochars examined,hemp biochar had the lowest oxidation-reduction potential(ORP;~0-100 mV),sorbed the greatest Na amount(up to 923 mg kg^(−1)),and released Ca and Mg(up to 115 and 63 mg kg^(−1),respectively)into solution,all of which led to a significant reduction in water SAR(from 8.8 to 7.3;17% decrease).Sodium sorption onto hemp biochar better fit a Langmuir versus a Freundlich isotherm,yet followed a pseudo-second-order model better than a pseudo-first-order kinetic model.The data suggest that Na ions formed a monolayer on the hemp biochar surface,influenced by associations withπelectrons,but given time the Na ions may diffuse into biochar pores or more slowly interact with biochar-borneπelectrons.Hemp biochar shows promise in reducing the SAR of Na-impacted waters.Future investigations should focus on additional laboratory,greenhouse,and field trials with hemp biochar and other biochars designed to have similar or superior properties for sorbing excess irrigation water Na and improving crop growth.