网围养殖对涡湖底栖动物群落组成及物种多样性的影响

2002年4月、7月、11月和2003年1月对滆湖底栖动物群落组成、分布及多样性现状进行了研究．结果表明，滆湖现有底栖动物31种，其中软体动物14种，淡水寡毛类6种，水生昆虫7种和水蛭4种．主要优势种为梨形环棱螺和羽摇蚊．相似性分析表明，滆湖网围养鱼区和网围养蟹区底栖动物群落组成相似程度较高，而都与非养殖区差异较大，说明网围养殖对底栖动物组成存在影响；而且网围养鱼对底栖动物的影响更甚于网围养蟹的影响．多样性分析表明，滆湖底栖动物多样性呈现自北向南递增以及夏秋低、冬春高的时空变化格局．图3表2参17     

Evaluation of a cost e ective technique for treating aquaculture water discharge using Lolium perenne Lam as a biofilter

Wastewater stabilization ponds generate low cost by-products that are useful for agriculture. The utilization of these by-products for soil amendment and as a source of nutrients for plants requires a high level of sanitation and stabilization of the organic matter, to maintain acceptable levels of soil, water and air quality. In this study, two aquaculture wastewater treatment systems; recirculating system and a floating plant bed system were designed to improve the quality of irrigation water in local communities with low income. In both systems the grass species Lolium perenne Lam was used as a plant biofilter while vegetable specie Amaranthus viridis was used to evaluate the performance of the system and the suitability of the phyto-treated water for irrigation. It was found that the harmful material removal rate for recirculating system was 88.9% for TAN （total ammonia nitrogen）, 90% for NO2--N, 64.8% for NO3--N while for floating plant bed system 82.7% for TAN, 82% for NO2--N and 60.5% for NO3--N. Comparative analysis of the efficiency of waste element removal between the two systems revealed that both systems performed well, however, plant growth was not robust for floating plant bed system while recirculating system is energy consuming. Although both systems did not attain sufficient levels of TN （total nitrogen） and TP （total phosphorus） load reduction, the treatment with L. perenne remarkably improved the irrigation water quality. A. viridis plants irrigated with the phyto-treated discharge water had lesser concentrations of heavy metals in their tissues compared to those irrigated with untreated discharge. The control plants irrigated with untreated discharge were also found to be highly lignified with few stems and small leaves.     

小型养殖塘水体中CH4、CO2和N2O浓度的时空变化特征及影响因素

养殖塘作为重要的温室气体排放源,水体中温室气体浓度的变化不仅是准确量化温室气体排放量的基础,还是明确其影响因素的重要依据.基于顶空平衡-气相色谱仪法对长三角一处典型的小型养殖塘水体中CH₄、CO₂和N₂ O浓度的时空变化特征以及影响因素进行了分析.结果表明,除春季外,在水温影响下,CH₄和N₂ O浓度在午间或午后出现高值;受水温和水生植物光合作用影响,CO₂浓度的高值出现在晨间光合作用较弱的时候.养殖塘水体中CH₄和CO₂浓度呈现秋季最高、冬季最低的季节变化特征,c（CH₄）在秋季和冬季的均值分别为176.34 nmol·L^-1和32.75 nmol·L^-1,主要受气温、水温和溶解氧（DO）影响;c（CO₂）秋季和冬季的均值分别为134.37 μmol·L^-1和23.10 μmol·L^-1,主要受水生植物光合作用和pH影响;c（N₂ O）在夏季最高,冬季最低,均值分别为97.05 nmol·L^-1和19.41 nmol·L^-1,主要受气温和水温影响.在空间上,垂直方向上,夏季养殖塘c（CH₄）随水深的加深而降低,表层与底层、中间层的浓度差值为71.28 nmol·L^-1和42.80 nmol·L^-1,秋季随水深的加深而升高,底层与表层的浓度差值为163.94 nmol·L^-1.c（CO₂）在夏季和秋季都表现为随着水深的加深而升高,其底层与表层的浓度差值分别为18.69 μmol·L^-1和29.90 μmol·L^-1.N₂ O浓度在垂直方向上无明显变化规律.水平方向上,夏季饲料及春季鸡粪投放的区域会出现CH₄、CO₂和N₂ O浓度的高值,春季和夏季CH₄浓度约为其他区域的1.34~1.98倍和1.95~2.42倍,春季N₂ O浓度和夏季CO₂浓度约为其他区域的1.13~1.26倍和1.39~1.74倍.     

池塘养殖(青虾)生态系统服务价值的系统动力学模型

生态服务价值的评估在近10 a来受到广泛关注,但大多基于静态评估框架,缺少动态分析。研究运用系统动力学的原理和方法,分析了青虾池塘养殖生态系统服务价值评估系统的内部结构,描绘了因果关系图及流图,建立了相应的系统动力学模型,初步预测不同决策方案下食物供给、固碳、释放氧气价值和富营养化环境成本在30 a内的变化趋势,结果表明:①无论采取何种决策,若系统外部环境不变,生态系统净服务价值的供给趋于稳定;②在池塘养殖生态系统中,释放氧气和固定二氧化碳等非市场价值是生态系统服务价值重要稳定的来源;③青虾养殖中投资变动在短期内往往会造成水产品市场价值的大幅波动,长期里则因投入的增加而增加,但增加率逐渐减少,最终达到稳定值;④在当前条件假设和环境参数的约束下,模型模拟结果与实测结果基本一致。     

Refining Nitrogen and Phosphorus Fertilization Strategies for Controlling the Toxigenic Alga Prymnesium parvum1

Kurten, Gerald L., Aaron Barkoh, Drew C. Begley, and Loraine T. Fries, 2010. Refining Nitrogen and Phosphorus Fertilization Strategies for Controlling the Toxigenic Alga Prymnesium parvum. Journal of the American Water Resources Association (JAWRA) 46(1):170-186. DOI: 10.1111/j.1752-1688.2009.00401.x Abstract: Previous studies have shown that three times weekly applications of phosphorus (30 μg P/l) and nitrogen (300 μg N/l) were effective at reducing the density and toxicity of the alga Prymnesium parvum in limnocorrals simulating a 40-day moronid (e.g., striped bass, Morone saxatilis, and palmetto bass, M. saxatilis ×Morone chrysops) fingerling culture period. However, this fertilization regime produced high pH and unionized ammonia-N concentrations that are detrimental to the survival of moronid fry and fingerlings. In two follow-up experiments we changed the source of N from ammonia to nitrate, reduced fertilization rates, and examined the effect of N-only or P-only fertilization. In the first experiment P fertilization rates were reduced by one-half to 15 μg P/l and NO₃-N was substituted for NH₃-N at the previously used rate of 300 μg N/l. In the second experiment, N fertilization rates were reduced to 150 μg N/l and the frequency of fertilization was determined by pH and P. parvum responses. Nitrate appeared to be as effective as ammonia as a source of N and when used in combination with P reduced P. parvum cell density and ichthyotoxicity. However, reduced N and P application rates and lower pond water temperatures during the study appeared to have decreased the speed at which fertilization produced these effects. While lower fertilization rates reduced algal productivity, high pH remained a concern for fish culture although pH was reduced to levels that might be acceptable with careful management of fish culture activities. Neither N-only nor P-only fertilization had a measurable effect on algal productivity or eliminated P. parvum and its toxicity. Furthermore, P-only fertilization may have increased P. parvum density and toxicity. For controlling P. parvum density and ichthyotoxicity we recommend a fertilization rate of 212 μg NO₃-N/l plus 30 μg PO₄-P/l applied three times weekly for aquaculture ponds where high pH is not a concern. Where high pH is a concern we recommend a fertilization rate of 117 μg NO₃-N/l plus 16 μg PO₄-P/l applied three times weekly with careful attention to afternoon pond pH.     

近岸养殖区抗生素的海洋环境效应研究进展

介绍了养殖中常用的抗生素及其在海洋环境中的持久性,并对抗生素使用对海洋环境所带来的不利影响,如对沉积物中有益微生物的活性抑制、对生源要素的生物地球化学循环的影响、以及长期使用抗生素引起病原生物的抗药性增强和水生生物体药物残留等问题进行了综述。对上述问题的探讨将有助于弄清抗生素在使用过程中对环境的影响,改善养殖环境质量,降低抗生素使用对环境的危害及对人类的影响。     

热带海水养殖清洁生产技术模式探讨

采用太阳光化学修复原理对典型热带地区--海南省某养殖场废水进行清洁闭环生态养殖技术初步探讨.采用现场定位观测实验研究方法,探讨高位池光化学循环净化装置对养殖废水中COD、SS等污染物的去除效应、脱氮解毒效应以及增氧效应等.结果表明,本实验装置能有效地实现热带地区高位池循环水养殖及养殖污水的"零排放",是满足环保要求的一种多功能、低成本、效果好的水体净化方法.     

生物活性炭填料反应器处理含盐水体的硝化性能

以颗粒活性炭为填料,采用盐度梯度两步驯化法构建含盐水体生物滤器硝化功能,研究了生物滤器稳定后水力停留时间(hydraulic retention time,HRT)、进水氨氮负荷和CODMn/N等对反应器硝化性能的影响。结果表明,25～27℃,盐度30的含盐水体生物滤器硝化功能构建需73 d,其中淡水生物滤器硝化功能构建需28 d,淡水驯化为盐度15的生物滤器需19 d,盐度15驯化为盐度30的生物滤器需26 d;实验条件下生物活性炭填料反应器中生物量达到146～742.1 nmolP/g-BAC;调节进水氨氮浓度2 mg/L左右时,最佳HRT为1 h,氨氮去除率达到84.98%,相应的氨氧化菌和硝酸菌氧吸收速率(oxygen uptake rate,OUR)分别为2.091和1.948 mg O2/(g-BAC.h);HRT为1 h时,随着进水氨氮负荷的加大,氨氮去除率逐渐降低,当进水氨氮负荷由0.12增加到0.48 g-N/(kg-BAC.d)时,氨氮去除率由84.98%降低到41.68%,同时氨氧化菌OUR由2.091降低到0.625 mg O2/(g-BAC.h);随着CODMn/N的升高,氨氮去除率下降,CODMn/N从1～8时,氨氮去除率由84.98%降低到53.64%,CODMn去除率却逐渐增加,由40.86%增加到93.59%,异养菌OUR随着CODMn/N升高呈上升趋势,最大达到0.914 mg O2/(g-BAC.h)。     

Optimization and evaluation of a bottom substrate denitrification tank for nitrate removal from a recirculating aquaculture system

A bottom substrate denitrification tank for a recirculating aquaculture system was developed. The laboratory scale denitrification tank was an 8 L tank (0.04 m2 tank surface area), packed to a depth of 5 cm with a bottom substrate for natural denitrifying bacteria. An aquarium pump was used for gentle water mixing in the tank; the dissolved oxygen in the water was maintained in aerobic conditions (e.g. > 2 mg/L) while anoxic conditions predominated only at the bottom substrate layer. The results showed that, among the four substrates tested (soil, sand, pumice stone and vermiculite), pumice was the most preferable material. Comparing carbon supplementation using methanol and molasses, methanol was chosen as the carbon source because it provided a higher denitrification rate than molasses. When methanol was applied at the optimal COD:N ratio of 5:1, a nitrate removal rate of 4591 ± 133 mg-N/m2 tank bottom area/day was achieved. Finally, nitrate removal using an 80 L denitrification tank was evaluated with a 610 L recirculating tilapia culture system. Nitrate treatment was performed by batch transferring high nitrate water from the nitrification tank into the denitrification tank and mixing with methanol at a COD:N ratio of 5:1. The results from five batches of nitrate treatment revealed that nitrate was successfully removed from water without the accumulation of nitrite and ammonia. The average nitrate removal efficiency was 85.17% and the average denitrification rate of the denitrification tank was 6311 ± 945 mg-N/m2 tank bottom area/day or 126 ± 18 mg-N/L of pumice packing volume/day.     

新型农村集约化养殖业发展中环境问题及管理对策

随着人们生活水平的提高,肉、蛋、奶等畜禽食品的消费量日趋上升,极大的刺激了畜禽养殖业的发展。这一发展使畜禽养殖特点发生了如下的变化,即由过去的分散经营,饲养头数少,主要分布在农区转变成现在的集中经营,饲养头数多,分布在城市郊区或新城区。本文分析了新型农村集约化养殖业发展中的环境问题,并针对这些问题提出了新型农村集约化养殖业的管理对策。