Integrated bioremediation techniques in a shrimp farming environment under controlled conditions

This study investigated the integrated bioremediation techniques for a shrimp culture system to reduce unconsumed feed and the contents of suspended solids（SS）, nutrients and organic pollutants using barracuda,clamworm, scallop, large algae and a biofilter. A multi-pool internal circulation system was designed to test the effectiveness of the techniques in the laboratory. The experimental result has shown that Argopecten irradians,Gracilaria lemaneiformis and the biofilter efficiently reduced the contents of SS, dissolved inorganic carbon（DIC）and dissolved organic carbon（DOC） in the breeding wastewater. The amount of unconsumed feed was significantly reduced by barracuda and clamworm, but there was an increase in the contents of SS, DIC and DOC in the water due to disturbance by the barracuda and clamworm. The capacity of macroalgae to extract inorganic nitrogen was insufficient. However, the balance of the nitrogen fixation rate of macroalgae and the biological exhaust nitrogen rate within the system should be fully considered. The use of the biofilter alone was not optimal for the remediation of organic matter in shrimp effluent so that auxiliary foam separation technology is needed to improve the ability of the system to remove macromolecules. This study provides a basis for the further development of remediation techniques to reduce the environmental impact of shrimp aquaculture.

Recent advances in bismuth-based photocatalysts:Environment and energy applications

Photocatalysis is an effective way to solve the problems of environmental pollution and energy shortage.Numerous photocatalysts have been developed and various strategies have been proposed to improve the photocatalytic performance.Among them,Bi-based photocatalysts have become one of the most popular research topics due to their suitable band gaps,unique layered structures,and physicochemical properties.In this review,Bi-based photocatalysts(BiOX,BiVO_(4),Bi_(2)S_(3),Bi_(2)MoO_(6),and other Bi-based photocatalysts)have been summarized in the field of photocatalysis,including their applications of the removal of organic pollutants,hydrogen production,oxygen production etc.The preparation strategies on how to improve the photocatalytic performance and the possible photocatalytic mechanism are also summarized,which could supply new insights for fabricating high-efficient Bi-based photocatalysts.Finally,we summarize the current challenges and make a reasonable outlook on the future development direction of Bi-based photocatalysts.

MoS_(2)的氧化还原特性综述:从污水治理到肿瘤治疗

环境污染及其衍生出的生物毒性是当今世界面临的两大挑战,寻找环境友好型材料是解决这类问题的有效策略之一.作为备受关注的类石墨烯纳米材料,二硫化钼(MoS_(2))性质优越,来源广泛,在污水处理领域具有强大的实际应用价值.与此同时,MoS_(2)还具有良好的生物相容性,因此研究学者们进而开发了其在生物应用领域的潜力,包括杀菌及肿瘤治疗等方面.本文总结了MoS_(2)在水处理及肿瘤治疗方面的应用及进展,并关注MoS_(2)在这两种应用场景下的创新.此外,我们还根据成本、回收效率对MoS_(2)的未来应用进行了展望.

Transparent Coating with TiO2 Nanorods for High-performance Photocatalytic Self-cleaning and Environmental Remediation

High-performance self-cleaning coatings are highly desired by the industry and market.Herein,we synthesized two kinds of ultrafine TiO2 nanocrystals,one is anatase dots with a diameter of 5 nm,and the other is rutile rods with 1.5 nm in width and 7 nm in length.The prepared TiO:nanocrystal is highly dispersed and stable in water over a month.The coating can be fabricated via a simple spraving method,displaying excellent optical properties and photocatalytic performance on self-cleaning and surrounding environment remediation.The transmittance of glass remains 80%-90%for visible and near-infrared light after 30 cycles of spray.RhB solution(50 mg/L)was applied to the coating surface and form a solid RhB layer was formed,which can be completely removed in 30 min's light irradiation.RhB aqueous solution(100 mL,5 mg/L)was purified after 180 min by a 10 cm×10 cmglass,on which the coating was sprayed 30 times.The concentrations of formaldehyde and PM2.5 in surrounding air displayed a significant decrease along 50 min's monitoring.This high-performance coating shows great potential for constructing functional coating on various substrates for industrial applications.

Efficient piezocatalytic activation of peroxydisulfate over Bi_(2)Fe_(4)O_(9):thickness-dependent synergy effect between peroxydisulfate activation and piezocatalysis

Piezocatalytic activation of persulfate(PS) has great application potential in environmental remediation;however,the relationship between piezocatalyst thickness and catalytic activity is not clear,limiting the further improvement of catalytic activity and application of the technology.Herein,the Bi_(2)Fe_(4)O_(9)(BFO) piezocatalysts with tunable thickness were prepared through a facile hydrothermal method by tuning the molar ratio of Bi(NO_(3)),5H_(2)O and FeCl_(3)·6H_(2)O for piezocatalytic activation of peroxydisulfate(PDS).The BFO with the smallest thickness exhibits excellent catalytic activity,and the SO_(4)^(·-)and ·OH are the major reactive oxygen species for degrading organic pollutants.Further XPS investigations and finite element analyses demonstrate that the decreased thickness of BFO not only exposes more Fe^(2+)sites for PDS activation,but also improve the piezoelectric effect to accelerate the regeneration of Fe^(2+),thus enabling an enhanced synergy effect between PDS activation and piezocatalysis for outstanding catalytic activity.This work provides an understanding of the relationship between thickness of piezocatalysts and its catalytic activity over PDS activation,facilitating the development of more efficient piezocatalysts and PS-based advanced oxidation processes.

Bifunctional copper modified graphitic carbon nitride catalysts for efficient tetracycline removal:Synergy of adsorption and photocatalytic degradation

In order to efficiently re move tetracycline in wastewater through the synergistic effect of adsorption and photocatalytic degradatio n,a series of novel composite materials(Cu doped g-C_(3)N_(4))were synthesized by two-pot hydrothermal method.It was found that the composite materials with optimized ratio(Cu/CN-1)displayed outstanding adsorption and photocatalytic performance as compared with pure g-C_(3)N_(4) photocatalyst.The removal efficiency of tetracycline(TC,50 mg/L)reached almost 99%within 30 min by Cu/CN-1 through the synergy of adsorption and photocatalysis under visible-light irradiation,which was the highest re moval efficiency ever reported.The adsorption kinetics and isotherms of TC on the Cu/CN-1 were well fitted with the pseudo-second-order kinetic model and Langmuir model,respectively.Moreover,it was confirmed that the main effective reactive groups were O_(2)^·and h^(+) in photocatalytic process.The Cu/CN-1 exhibited high stability and excellent reusability after five cycle experiments.Finally,the mechanism of synergy between Cu and g-C_(3)N_(4) was proposed:on the one hand,the decoration of Cu particles significantly increased the adsorption sites of Cu/CN-1 to tetracycline,on the other hand,the modification of Cu particles effectively inhibits charge recombination and broadens the visible light absorption range of the photocatalyst.This study provided a promising photocatalyst to be used for TC removal in the actual wastewater.