The dried fruit mite Carpoglyphus lactis (Acari: Carpoglyphidae) is a suitable alternative prey for Amblyseius herbicolus (Acari: Phytoseiidae)

Being generalist predators makes many members of the Phytoseiidae family a more favourable choice for biocontrol. Amblyseius herbicolus, a predator of several phytophagous pest mites and insects, has recently gained focus as an important biocontrol agent. Most studies focus on providing alternative food such as pollens as a way to increase their persistence on the targets when prey is absent. In this study, we evaluated the developmental and reproductive performance of A. herbicolus on two different diets: the dried fruit mite Carpoglyphus lactis and Raupo Typha orientalis pollen. The groups treated with C. lactis took 7 days to reach adulthood, while the groups treated with pollen took 11 days. The pollen-treated mites did not reproduce but this is likely due to the reduction of pollen quality. When given C. lactis, A. herbicolus produced more than 20 eggs over two weeks and the adults survived 18–19 days. The ratio of A. herbicolus egg to C. lactis adult used (1:20, 40 & 120) in the experiment did not affect the final population size. Cannibalism and competition seemed to affect all treatments, especially those cells started with three A. herbicolus eggs. Under laboratory conditions, A. herbicolus can be successfully cultured using C. lactis, which is an advantageous method for the laboratory and mass rearing of A. herbicolus.

Ecological Restoration of Wetland Polluted by Heavy Metals in Xiangtan Manganese Mine Area

Due to manganese mining and slag accumulation, the geological structure of the wetland polluted by heavy metals in Xiangtan Manganese Mine area was seriously damaged, hence biodiversity loss, severe soil, and water pollution, as well as serious heavy metal pollution to food, vegetables, and other natural sources. In order to restore the ecological environment of the mining area, in 2015, the ecological restoration test of heavy metal polluted wetlands in the mining area was carried out. The results showed that the Mn content of different parts of Koelreuteria paniculata root from high to low order: fine root > small root > medium root > large root. The Mn content of different parts of Elaeocarpus decipiens root from high to low order: large root > medium root > small root > fine root. The order of Mn content in plants of the wetland restoration from high to low is as follows: Canna warscewiezii > Thalia dealbata > Boehmeria > Pontederia cordata > Typha orientalis > Nerium oleander > Softstem bulrush > Iris germanica > Acorus calamus > Arundo donax > Phragmites australis; The order of Internal Cu content from high to low is as follows: Acorus calamus > Thalia dealbata > Softstem bulrush > Canna warscewiezii > Typha orientalis > Arundo donax > Boehmeria > Iris germanica > Pontederia cordata > Nerium oleander > Phragmites australis; Zn content from high to low order is as follows: Canna warscewiezii > Acorus calamus > Thalia dealbata > Typha orientalis > Pontederia cordata > Arundo donax > Softstem bulrush > Iris germanica > Boehmeria > Phragmites australis > Nerium oleander; Cd content from high to low order is as follows: Phragmites australis > Softstem bulrush > Thalia dealbata > Nerium oleander > Boehmeria > Canna warscewiezii > Acorus calamus > Iris germanica > Typha orientalis > Pontederia cordata > Arundo donax. The results of this study have provided a theoretical basis and decision-making reference for the evaluation of heavy metals polluted wetland restoration, protection, and reconstruction effects and the selection of ecological restoration modes.

KHẢ NĂNG CHỐNG CHỊU, HIỆU QUẢ XỬ LÝ CHẤT Ô NHIỄM TRONG NƯỚC THẢI CHĂN NUÔI SAU BIOGAS CỦA THỦY TRÚC (Cyperus alternifolius) VÀ CỎ NẾN (Typha orientalis)

Từ thực trạng chất lượng nước thải sau biogas tại các trang trại chăn nuôi lợn, nghiên cứu đã lựa chọn hai loài thực vật thủy sinh để xử lý nước thải theo định hướng nghiên cứu ứng dụng công nghệ bãi lọc trồng cây nhân tạo. Thí nghiệm được thiết kế nhằm đánh giá khả năng chống chịu COD, NH4+ và pH của Thủy trúc (Cyperus alternifolius) và Cỏ nến (Typha orientalis) thông qua khả năng sinh trưởng ở các nồng độ khác nhau. Cả hai loài thực vật cho sinh khối ổn định trong dải pH từ 5 đến 9, nồng độ COD đến 1000 mg/L và nồng độ NH4+ từ 50 đến 250 mg/L. Hiệu suất xử lý TSS (Total Suspended Solids – Tổng chất rắn lơ lửng), COD (Chemical Oxygen Demand – Nhu cầu oxy hóa học), NH4+, T-N (Total Nitrogen – Tổng nitơ) của Thủy trúc tương ứng là 85,9%, 76,8%, 76,8%, 66,8% và Cỏ nến là 85,4%, 66,5%, 61,5%, 52,0%. Chất lượng nước thải sau xử lý đều đạt quy chuẩn cho phép đối với nước thải chăn nuôi (QCVN62-MT:2016/BTNMT, cột B). Tuy nhiên, Thủy trúc có ưu thế hơn nhờ khả năng chống chịu tối ưu, hiệu quả xử lý và thời gian xử lý các chất ô nhiễm của loài thực vật này.

Khả năng sinh trưởng và tích lũy sinh khối của bồn bồn (Typha orientalis), cỏ bàng (Lepironia articulata) và năn tượng (Scirpus littoralis) trồng trên đất phèn

Nghiên cứu được thực hiện nhằm đánh giá khả năng sinh trưởng và tích lũy sinh khối ở ba loài thực vật thủy sinh gồm bồn bồn (Typha orientalis C. Presl), cỏ bàng (Lepironia articulata Retz. Domin.) và năn tượng (Scirpus littoralis Schrab.) trồng trên đất phèn ở Đồng bằng sông Cửu Long. Trước khi trồng cây, thí nghiệm đánh giá khả năng cải thiện pH đất bằng CaCO3 được thực hiện trên 2 nghiệm thức bón 2 tấn CaCO3/ha và không bón CaCO3 (được xem là nghiệm thức đối chứng). Đất này được sử dụng để trồng cây cho thí nghiệm tiếp theo với ba loài cây, bố trí theo thể thức hoàn toàn ngẫu nhiên với ba lần lặp lại. Sau 42 ngày ngâm đất, giá trị pH trong đất đạt 4,02 ở nghiệm thức có CaCO3 và cao hơn so với đất ban đầu (pH=3,02). Sau 90 ngày trồng cây, khả năng sinh trưởng và tiềm năng tích lũy sinh khối tươi và khô của phần thân và rễ cây và chỉ số diệp lục tố (SPAD) của bồn bồn và năn tượng tốt hơn khi cây trồng trên đất phèn có bón CaCO3.

Mace-like carbon fibers/ZnO nanorods composites derived from Typha orientalis as ultralight and high-performance electromagnetic wave absorber

Inspired by the nature, biomass-derived carbon attracts many attentions as the electromagnetic wave absorption (EMA) material owing to its advantages including abundant, low cost, renewable and environmentally friendly. However, it is difficult to make further breakthrough in effective absorption bandwidth (EAB) due to the impedance mismatch. In this work, mace-like carbon fibers/ZnO nanorods composites (BDCFs@ZnO) derived from Typha orientalis were prepared via a carbonization process and a subsequent hydrothermal process for the first time. The unique hollow structure of BDCFs and the construction of 3D interconnected conductive network led to the strong conduction loss and multiple reflection. The BDCFs sample possesses an excellent EMA performance with an ultralow filling ratio of only 5wt%. After directionally growing of the ZnO nanorods, an exceptional RL of -62.35 dB at 14.12 GHz and the EAB achieves 6.8 GHz at the thickness of 2.29 mm at a filling ratio of 15wt% were revealed. Mace-like ZnO with suitable permittivity effectively avoid the reflection result from direct contraction between EMW and carbon fiber, further improving impedance match. Simultaneously, a dielectric sum-quotient model was proposed to analyze the EMA performance of the samples. This work not only offers an inspiration for the development of dielectric loss-type EMA materials with lightweight and strong EMA performance by a sustainable, low-cost and easily available approach, but also provides an important strategy toward biomass-derived carbon-fiber-based composites in other fields.

Application of Bioelectrochemical Technique in Energy Recovery and CH4 Control From Constructed Wetland (CW) and Associated Biochemical Mechanisms

In the context of global warming, the bioelectrochemical method (microbial fuel cell MFC) was proposed for CH4 control from CWs. The main focus is to further explore the effect of plant roots location at the electrode, plant species on CH4 emissions, bioelectricity generation and the mechanism underlying competition between electrogenesis and methanogenesis at the anode. The results showed that the operation of MFC effectively reduced the CH4 emissions and promoted COD removal rates. CH4 emission was significantly higher in open circuit (6.2 mg m-2 h-1) than in closed circuit reactors (3.1 mg m-2 h-1). Plant roots at the cathode had the highest electricity generation and the lowest CH4 emissions. The highest power generation (0.49 V, 0.33 w m-3) and the lowest CH4 emissions (2.3 mg m-2 h-1) were observed in the reactors where Typha Orientalis was planted with plant roots at the cathode. The role of plants in strengthening electron acceptor was greater than that of plant rhizodeposits in strengthening electron donors. q-PCR and correlation analysis indicated that the mcrA genes and CH4 emissions were positively correlated (r=0.98, p<0.01), while no significant relationship between CH4 emissions and pmoA genes was observed. More nanowires, which are conductive to electron transfer, were found when plant roots were in cathode by scanning electron microscope (SEM). Illumina sequencing revealed that more abundant exoelectrogens and denitrifying bacteria (Geobacter, Desulfobulbu, Nitrospira and Anaerolinea) were observed when plant roots located in cathodes. Strictly acetotrophic archae (Methanosaetaceae) were likely main electron donor competitors with exoelectrogens. In addition, plant species played a more important role in CH4 emissions and electricity generation than the plant roots location at the electrode. Therefore, it is necessary to strengthen plant configuration to reduce CH4 emissions, so as to promote sustainable development of wastewater treatment.