Comprehensive Evaluation on China's Law on Water Pollution Prevention and Control

The newly revised Law of the People’s Republic of China on Prevention and Control of Water Pollution is crucial for pollution prevention and control in China. In this paper, we first review the achievements of the law in eight aspects since its implementation on January 1, 2018. Subsequently, we analyze the issues in implementing the law from four perspectives: (1) water environment management system and mechanism, (2) supervision over water pollution law enforcement, (3) drinking water source protection and groundwater pollution prevention, and (4) water pollution prevention and control. Accordingly, four countermeasures are proposed from the aspects of management system, law enforcement capabilities, water source protection, and pollution prevention. Specifically, efforts should be put into coordinated watershed management, river chief system perfection, and water quality improvement, thus to promote the up-to-standard discharge of industrial wastewater, pollutant interception and treatment of municipal pipe networks, recycling of municipal activated sludge, low-carbon and economical treatment of rural sewage, and rural non-point source pollution prevention

Comparison of Adsorbents for Cesium and Strontium in Different Solutions

Adsorption is an effective method to remove cesium and strontium from a solution. Although a variety of adsorbents has been reported, it is difficult to compare their adsorption properties due to different experimental conditions (such as solution concentration, volume, composition, temperature, etc.). In this paper, a series of adsorbents for the adsorption of cesium and strontium (ammonium phosphomolybdate, Prussian blue, sabite, clinoptilolite, titanium silicate) were synthesized and characterized using XRD, IR and SEM, and their adsorption performance in mixed solution (containing Li, Na, K, Cs, Ca, Sr and Mg ions, 1 mmol L−1), artificial seawater and salt lake brine were studied under the same conditions; in addition, the adsorption mechanism was elucidated. The results showed that ammonium phosphomolybdate has the largest adsorption capacity for cesium in the mixed solution. In artificial seawater and salt lake brine, Prussian blue displays the highest cesium adsorption capacity and the best selectivity. The multi-adsorption mechanisms are beneficial to the selective adsorption of Prussian blue in complex solutions. These results are useful for choosing adsorbents for cesium and strontium in applications

Application of Landfill Gas-Water Joint Regulation Technology in Tianjin Landfill

Landfills have long been widely used to dispose of Municipal Solid Waste (MSW). However, many landfills have faced early closure issues in recent years due to overload operations. Although in-situ aeration technology can quickly stabilize MSW, low oxygen utilization rates present a general problem that results in high energy-consuming and operating costs. This research aims to improve oxygen utilization efficiency by observing the dynamic respiratory index and the removal of contaminants. Three continuous reactors were constructed and designed with targeted aeration and re-circulation schemes for different landfill ages. The results show that a well-designed aerobic, semi-aerobic, and anaerobic reactor can fully degrade the organic components of MSW with different landfill ages, and the quantity of waste has been reduced by more than 60%. Additionally, it was disclosed that gas-water joint technology has a promotional effect on activating microorganisms

Zwitterion-like, Charge-Balanced Ultrathin Layers on Polymeric Membranes for Antifouling Property

Zwitterions of charge-balanced units have super-low fouling properties induced by ionic solvation, but their extensive applications in polymeric substrates are strictly constrained by current constructing strategies. A zwitterion-like, charge-balanced ultrathin layer with high antifouling capacity was covalently constructed on delicate aromatic polyamide (PA) reverse osmosis (RO) membranes via a mild and solvent-free grafting-to strategy. Two oppositely charged commercial short-chain carbonyl alkenes, 2-acrylamido-2-methylpropanesulfonic acid (AMPS) and methacryloxyethyltrimethylammonium chloride (DMC), were directly mixed-grafted with amino groups on PA RO membrane surface via Michael addition. Under ambient temperature and pressure, these oppositely charged compounds were assembled into a zwitterion-like, charge-balanced ultrathin layer. The dynamic fouling experiments indicated that the modified membrane exhibited strong antifouling properties and excellent permeation recovery abilities. Surface characterization revealed that the selective layer thickness and surface roughness were not measurably changed. More meaningful is that the typical ridge-and-valley surface structure and the excellent separation performance were both well preserved after modification. This opens a universal avenue to construct a zwitterion-like, ultrathin antifouling layer on the delicate polymer substrate without compromising its original matrix structure and performance, which has promising application in areas of biosensors, tissue engineering, and biomaterials

Utilization of five data mining algorithms combined with simplified preprocessing to establish reference intervals of thyroid-related hormones for non-elderly adults

Abstract Background Despite the extensive research on data mining algorithms, there is still a lack of a standard protocol to evaluate the performance of the existing algorithms. Therefore, the study aims to provide a novel procedure that combines data mining algorithms and simplified preprocessing to establish reference intervals (RIs), with the performance of five algorithms assessed objectively as well. Methods Two data sets were derived from the population undergoing a physical examination. Hoffmann, Bhattacharya, Expectation Maximum (EM), kosmic, and refineR algorithms combined with two-step data preprocessing respectively were implemented in the Test data set to establish RIs for thyroid-related hormones. Algorithm-calculated RIs were compared with the standard RIs calculated from the Reference data set in which reference individuals were selected following strict inclusion and exclusion criteria. Objective assessment of the methods is implemented by the bias ratio (BR) matrix. Results RIs of thyroid-related hormones are established. There is a high consistency between TSH RIs established by the EM algorithm and the standard TSH RIs (BR = 0.063), although EM algorithms seems to perform poor on other hormones. RIs calculated by Hoffmann, Bhattacharya, and refineR methods for free and total triiodo-thyronine, free and total thyroxine respectively are close and match the standard RIs. Conclusion An effective approach for objectively evaluating the performance of the algorithm based on the BR matrix is established. EM algorithm combined with simplified preprocessing can handle data with significant skewness, but its performance is limited in other scenarios. The other four algorithms perform well for data with Gaussian or near-Gaussian distribution. Using the appropriate algorithm based on the data distribution characteristics is recommended

Homocoupling Reaction of Aryl Halides Catalyzed by Metal Cations in Isostructural Coordination Polymers

We have obtained a suite of two-dimensional layered isostructural coordination polymers [M­(pypa)₂­(H₂O)₂]_<i>n</i> (M = Mn (<b>1</b>), Co (<b>2</b>), Ni (<b>3</b>), Cu (<b>4</b>), respectively), Hpypa = 1<i>H</i>-[3-(4-pyridy)­pyrazole]­propionic acid), and used them in catalyzing the homocoupling of aromatic halides. <b>3</b> and <b>4</b> exhibit preeminent catalytic performance on the homocoupling of aryl bromide or aryl iodide without byproducts, while <b>2</b> only promoted the homocoupling of aryl iodide. But <b>1</b> showed no catalytic activities for all tested aromatic halides. Subsequently, density functional theory was performed for the balanced geometry frameworks, net charges of atoms, and energy of frontier molecule orbits. By using this method we determined that the catalytic performance was influenced by central metal ions. For further improving the catalytic performance, polyvinylpyrrolidone or polyethylene glycol 20000 (PEG 20000) was used as surfactants to synthesize the microscales of <b>3</b>’s (<b>3a</b> and <b>3b</b>). <b>3a</b> and <b>3b</b> showed more preeminent catalytic activity than <b>3</b>