An ability to real-time and continuously monitor ammonium/ammonia profiles of coastal waters over a prolonged period in a simple and maintenance-free fashion would enable economic conducting large-scale assessments, providing the needed scientific insights to better control and mitigate the impact of eutrophication on coastal ecosystems. However, this is a challenging task due to the lack of capable sensors. Here, we demonstrate the use of a membrane-based conductometric ammonia sensing probe (CASP) for real-time monitoring of ammonia levels in coastal waters.
View Article and Find Full Text PDFAim: Ammonia released during the storage period from pig manure causes severe air pollution and odor issues, ultimately leading to nitrogen loss in the manure. In this study, we investigated the application of 13 Bacillus spp. strains isolated from paddy soil and their potential to minimize reactive nitrogen loss during pig manure storage at 28°C and initial moisture content at 76.
View Article and Find Full Text PDFDuring the COVID-19 pandemic, the use of chlorine-based disinfectants has surged due to their excellent performance and cost-effectiveness in intercepting the spread of the virus and bacteria in water and air. Many authorities have demanded strict chlorine dosage for disinfection to ensure sufficient chlorine residual for inactivating viruses and bacteria while not posing harmful effects to humans as well as the environment. Reliable chlorine sensing techniques have therefore become the keys to ensure a balance between chlorine disinfection efficiency and disinfection safety.
View Article and Find Full Text PDFGood practices in controlling ammonia produced from the predominant agricultural contributor, crop farming, are the most direct yet effective approaches for mitigating ammonia emissions and further relieving air pollution. Of all the practices that have been investigated in recent decades, fertilizer amendment technologies are garnering increased attention as the low nitrogen use efficiency in most applied quick-acting fertilizers is the main cause of high ammonia emissions. This paper systematically reviews the fertilizer amendment technologies and associated mechanisms that have been developed for ammonia control, especially the technology development of inorganic additives-based complex fertilizers, coating-based enhanced efficiency fertilizers, organic waste-based resource fertilizers and microbial agent and algae-based biofertilizers, and their corresponding mechanisms in farmland properties shifting towards inhibiting ammonia volatilization and enhancing nitrogen use efficiency.
View Article and Find Full Text PDFAn ability to real-time, continuously monitor soil ammonia emission profiles under diverse meteorological conditions with high temporal resolution in a simple and maintenance-free fashion can provide the urgently needed scientific insights to mitigate ammonia emission to the atmosphere and improve agricultural fertilization practice. Here, we report an open-chamber deployment unit embedded a gas-permeable membrane-based conductometric sensing probe (OC-GPMCP) capable of on-site continuously monitoring soil ammonia emission flux ( [Formula: see text] ) -time (t) profiles without the need for ongoing calibration. The developed OC-GPMCPs were deployed to a sugarcane field and a cattle farm under different fertilization/meteorological conditions to exemplify their real-world applicability for monitoring soil ammonia emission from agricultural land and livestock farm, respectively.
View Article and Find Full Text PDFBiogas slurry (BS) and bio-waste hydrothermal carbonization aqueous phase (HP) are nutrient-rich wastewater. To prevent environment contamination, transforming BS and HP into synthetic fertilizers in the agricultural field can potentially realize resource utilization. We hypothesized that acidic HP could neutralize alkaline BS, adjusting floodwater pH from 6.
View Article and Find Full Text PDFHighly toxic chlorine gas imposes serious health risks in the workplace. The ability to on-site, real-time monitoring of instantaneous and time-weighted average (TWA) chlorine gas concentrations in a simple, sensitive, accurate, and reliable manner would be highly beneficial to improve workplace health and safety. Here, we propose and experimentally validate a gaseous chlorine detection principle based on a ,-diethyl--phenylenediamine sulfate salt/Cl colorimetric reaction-controlled membrane process to regulate the gaseous chlorine transport across a gas-permeable membrane that enables the establishment of a time-resolved analytical relationship to quantify chlorine concentration by multidata points with dramatically enhanced accuracy and reliability.
View Article and Find Full Text PDFAmmonia is a necessary monitoring parameter that should be controlled within an optimum range in the whole process of wastewater treatment and recycling, but few reliable real-time monitoring technologies are available currently under such harsh water conditions. This study proposes a continuous conductometric flow-through analyzer for ammonia monitoring (CFAA) in the wastewater treatment process. It is developed based on the gas diffusion mechanisms, and the proposed analytical principle has been validated in which the real-time conductivity increment rate is linearly proportional to the real-time ammonia concentration in the sample.
View Article and Find Full Text PDFAmmonium is an important nutrient in primary production; however, high ammonium loads can cause eutrophication of natural waterways, contributing to undesirable changes in water quality and ecosystem structure. While ammonium pollution comes from diffuse agricultural sources, making control difficult, industrial or municipal point sources such as wastewater treatment plants also contribute significantly to overall ammonium pollution. These latter sources can be targeted more readily to control ammonium release into water systems.
View Article and Find Full Text PDFAquatic ammonia has toxic effects on aquatic life. This work reports a gas-permeable membrane-based conductivity probe (GPMCP) developed for real-time monitoring of ammonia in aquatic environments. The GPMCP innovatively combines a gas-permeable membrane with a boric acid receiving phase to selectively extract ammonia from samples and form ammonium at the inner membrane interface.
View Article and Find Full Text PDFWith closing water loop through purified recycled water, wastewater becomes a part of source water, requiring reliable wastewater quality monitoring system (WQMS) to manage wastewater source and mitigate potential health risks. However, the development of reliable WQMS is fatally constrained by severe contamination and biofouling of sensors due to the hostile analytical environment of wastewaters, especially raw sewages, that challenges the limit of existing sensing technologies. In this work, we report a technological solution to enable the development of WQMS for real-time abnormal event detection with high reliability and practicality.
View Article and Find Full Text PDFNutrient concentrations in freshwater are highly variable over time, with changes driven by weather events, anthropogenic sources, modifications to catchment hydrology or habitats, and internal biogeochemical processes. Measuring infrequently collected grab samples is unlikely to adequately represent nutrient concentrations in such dynamic systems. In contrast, in situ passive sampling techniques, such as the "diffusive gradients in thin films" (DGT) technique, provide time-weighted average analyte concentrations over the entire deployment time.
View Article and Find Full Text PDFA new diffusive gradients in a thin film (DGT) technique, using Microlite PrCH cation exchange resin, was developed and evaluated for measuring NH4-N in freshwaters. Microlite PrCH had high uptake (>92.5%) and elution efficiencies (87.
View Article and Find Full Text PDFConcentrations of heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn) were measured in water, sediments, Ceratophyllum (hornwort), and Bellamya sp. (edible snail) from residential, mixed (industrial and commercial), and agricultural areas with rural rivers in the Taihu Lake region, China. Zn concentrations were the highest, whereas Cd concentrations were the lowest among the six metals in water, sediments, and aquatic organisms.
View Article and Find Full Text PDFTo improve the efficiency of wastewater treatment and characterize the microorganism communities, microorganisms were cultured and concentrated in hybrid bioreactors at a low temperature (~4 °C, low-temperature hybrid bioreactor, LTHB) and room temperature (~25 °C, room-temperature hybrid bioreactor, RTHB). The performance of the LTHB and RTHB in terms of COD removal efficiency, dehydrogenase activity and functional diversity of microbial communities were evaluated. The results show COD removal efficiency increased gradually over time from 39.
View Article and Find Full Text PDFWith the public's enhanced awareness of eco-safety, environmentally benign measures based on microorganisms and microbial aggregates have become more accepted as methods of removing pollutants from aquatic systems. In this review, the application of microorganisms and microbial aggregates for removing pollutants from aqueous solutions is introduced and described based on mechanisms such as assimilation, adsorption, and biodegradation. The advantages of and future studies regarding the use of microorganisms and microbial aggregates to remove pollutants are discussed.
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