Utilization of Ion-Exclusion Chromatography for Water Quality Monitoring in a Suburban River in Jakarta, Indonesia

Milestone Studies on Ion-exclusion Chromatography of Ionic and Nonionic Substances Utilizing Multifunctional Separation Mechanism of Ion-exchange Resins

Ion-exclusion chromatography (IEC) is categorized as a type of ion chromatography and is recognized as a simple and convenient water quality monitoring technology for a variety of ionic and nonionic substances. This review, mainly focusing on historical milestone studies by various authors, outlines the archives that concern the separation sciences and practical applications obtained from a variety of IEC modes used for water-quality monitoring as follows: (1) early-developed IEC; (2) IEC using enhanced conductivity detection for weak ionic substance; (3) IEC using nonionic substances eluents such as sugars or polyols; (4) vacancy IEC based on a novel separation concept; (5) applications to the water quality monitoring of inorganic ionic-nutrients; (6) simultaneous IEC and cation-exchange chromatography of anions and cations; and (7) the multicomponent IEC combining different separation modes and detection methods with the expansion of applicable fields, such as for food analysis or material evaluations.

Major ions in drinking and surface waters from five cities in arid and semi-arid areas, NW China: spatial occurrence, water chemistry, and potential anthropogenic inputs

A total of 161 water samples were collected from five large and medium-sized city rivers and residential tap waters, Xi'an and Yan'an in Shaanxi province, Xining in Qinghai province, Lanzhou in Gansu, and Urumqi in Xinjiang province, within arid and semi-arid area (NW China). The pH, EC parameters, and concentrations of 10 major ions (F^-, Cl^-, HCO₃^-, NO₃^-, SO₄^2-, NH₄⁺, K⁺, Na⁺, Mg²⁺, Ca²⁺) in the drinking waters (DWs) and surface waters (SWs) were analyzed to determine the ion chemistry, geochemical process, and potential anthropogenic input sources and to assess the water quality for drinking, domestic, and irrigation purposes. Durove diagrams and Gibbs diagram indicated that the ions Ca²⁺ and HCO₃^- dominant in DWs from Xi'an and Xining were of Ca²⁺-(HCO₃^- + SO₄^2-) type, while sulfate and Na⁺ dominant in SWs, and Na⁺/K⁺-SO₄^2- type was for Yan River in Yan'an and Peaceful Canal in Urumqi, their water chemistry influenced by evaporation and rock dominance, and evaporation and fractional crystallization, respectively. Meanwhile, Na⁺/K⁺/Ca²⁺-HCO₃^-/SO₄^2- type dominated in Huang River in Xining and Yellow River in Lanzhou, which dominated by rock weathering. The quality assessments showed that in general the drinking waters were suitable for domestic purposes. However, the high values of NO₃^- at some sites influenced by agricultural and industrial inputs made it unsafe for drinking and demand detailed regional drinking water investigations. The assessment of SWs showed that the waters from Yan River in Yan'an and Yellow River in Lanzhou and Huang River in Xining would be used for irrigation. However, high values of SAR, Na%, RSC, and EC at sites in Peaceful Canal restricted suitability for irrigation, and not recommended for drinking water sources. It was noted that for the sustainable development of surface water, a reduction of discharge water from human activities and/or an increase in the fresh water inflow to the surface were needed.

Vetiver and Dictyosphaerium sp. co-culture for the removal of nutrients and ecological inactivation of pathogens in swine wastewater

Swine wastewater poses chemical and biological risks because it contains high concentrations of ammonia and diverse species of pathogens. Herein, a vetiver-Dictyosphaerium sp. co-culture for the rapid removal of ammonia and the effective inactivation of pathogens was developed. Plants and microalgae benefited mutually and co-utilized the nutrients in the wastewater in the co-culture. The pathogens were inactivated by reactive oxygen species that were released by the microalgae as well as the supersaturated concentrations of dissolved oxygen in the enclosed bioreactor. In a greenhouse experiment, the time required for wastewater NH4-N to decrease from 102 mg L-1 to 5 mg L-1 was 65.5 days, 34.2 days, and 13.3 days in the plant culture, the algal culture, and the plant-algal co-culture, respectively. Among the 35 detected genera of bacteria, the operational taxonomic units for 31 tended to decrease with culture time in the plant-algal co-culture. Additionally, certain bacteria (e.g., Escherichia spp.) were completely removed by day 9 or 15, and the aerobic phototrophic bacterium Erythromicrobium spp. became most abundant on day 15 in the plant-algal co-culture. Important positive interactions that were observed between plants and microalgae included co-utilization of the nutrients, wastewater acidification through plant root respiration and algal growth with reduced ammonia toxicity, algal depletion of bicarbonate and alleviation of bicarbonate toxicity to plants, and release of oxygen from algal photosynthesis and plant growth with reduced hypoxic stress.

High-quality, ecologically sound remediation of acidic soil using bicarbonate-rich swine wastewater

The swine industry in China is experiencing a wastewater crisis. In this work, we found that swine wastewaters were particularly high in bicarbonate (1.52-9.25 g/L, mean = 5.68 g/L, n = 42). The high level of bicarbonate may add to the pollution load during discharge. We therefore suggest a new method for bicarbonate-rich wastewater remediation in acidic soil. In our laboratory irrigation experiments, wastewater irrigation efficiently increased the pH and decreased the exchangeable aluminum in the acidic soil. Furthermore, the wastewater method efficiently remediated the entire soil body, while lime application remediated only a portion of the topsoil. Wastewater irrigation also improved soil fertility (e.g., by increasing the phosphorus availability in acid soil).