气浮-水解酸化-CASS工艺处理番茄制品生产废水的工程应用

番茄制品生产废水含有大量糖类、有机酸,有机物浓度高,易于生化降解,采用气浮-水解酸化-CASS处理工艺,工程应用表明,出水可达GB 8978—1996《污水综合排放标准》一级排放标准,且投资省、运行费用低,具有适用范围广、抗冲击负荷能力强等特点,具有较高的推广应用价值。     

膜滤与酸析处理草浆黑液的实验研究

采用无机膜过滤和磷酸酸析 2种方法来处理草浆造纸的黑液 ,比较了 2种方法的截留和分离效果。膜滤COD的截留率高于酸析 ,但从木素以及硅脱除的角度看 ,酸析的效果较佳。酸析后滤液可以苛化利用 ,以提高经济效益 ;而无机膜过滤是一个物理过程 ,工艺相对简单 ,流程短 ,其渗透液可以考虑直接回用。     

酸化-萃取法处理丁辛醇废水

采用酸化-萃取法处理齐鲁石化公司第二化肥厂的丁辛醇废水（简称废水）,用硫酸调节废水的pH,以该厂产品异辛醇为萃取剂,考察了各种因素对萃取效率的影响,得出较佳工艺条件：废水的pH为2．5,废水与萃取剂的体积比为4,废水温度为10℃,废水与萃取剂混合时的振摇时间为60s,萃取相和萃余相的静置分离时间为10min。在该条件下对COD为42244mg/L的废水进行二级错流萃取,COD去除率为86．82％。该法可实现对废水进行处理和资源回收的双重目的。     

氟苯生产废水处理及资源化技术

采用酸化、萃取、反萃、除氟、电催化氧化技术处理氟苯生产废水（简称废水）。工艺条件为：以硫酸为酸化剂,pH小于等于1;萃取温度10～25℃,搅拌时间大于4min,油水比（萃取剂与废水的体积比）1：4．0;反萃碱油比（NaOH溶液体积与油相体积比）1：3,NaOH质量分数10％;除氟时先加入2倍理论计算量的氯化钙、后加入氧化钙调pH至7～8;电催化氧化时粒子群电催化反应器槽电流2．0～2．5A,停留时间40～60min。处理后废水的COD、苯酚、F^-、石油类去除率分别高于99．3％,99．9％,99．8％,99．9％,苯酚回收率高于93．5％;出水COD、苯酚、F^-、石油类的浓度低于GB8978—1996《污水综合排放标准》中的一级排放标准。     

Soil Quality Evolution After Land Use Change From Paddy Soil to Vegetable Land

A survey was done in 15 typical villages, 150 soil and 86 vegetable plant samples were taken in Jiaxin prefecture of the Taihu Lake region, northern Zhejian province. Results indicate that after 15–20 years land use changed from the paddy rice–wheat (or oilseed rape) double cropping system, to a continuous vegetable land has caused soil quality dramatic change. (1) Acidification: average soil pH was 5.4; about 61% of total samples were pH < 5.5. It was 0.9 units lower than 10 years ago with same upland vegetable cultivation and was 1.2 units lower than soil pH of paddy rice–wheat (or oilseed rape) rotation. (2) Fertilizer salt accumulation: the average salt content was 0.28%, among these about 36.2% of the total samples contained more than 0.3%. (3) Nitrate N and available phosphorus (P) over accumulation: on average it was 279 mg NO₃-N/kg, and 45–115 mg P/kg. Nitrate N four times higher and available P 4–10 times more than it is in present paddy rice–wheat rotation soils respectively. This has caused wide concern because of possible groundwater and well drinking water pollution by leached nitrate N and the P losses to water by runoff from vegetable lands induce surface water eutrophication.     

水解酸化-气浮-厌氧-好氧处理苎麻脱胶废水

江西瑞昌某苎麻公司产生大城污染严重的苎麻废水。废水处理规模300m^3／d。采用水解酸化-气浮-厌氧-好氧为主体的处理工艺,出水达到GB8978—96一级排放标准．该工艺具有耐冲击负荷、运行稳定、易于管理和运行费用低等优点。     

剩余污泥超声预处理后水解酸化特性

为探讨剩余污泥超声预处理后的水解酸化特性,考察了0.6 W/mL、5 min和1 W/mL、5 min 2种超声预处理条件下污泥水解酸化过程有机质、氮、磷的释放情况。实验结果表明,2种超声预处理均可促进污泥水解酸化,并且0.6 W/mL比1 W/mL的超声预处理更有利于SCOD的释放、VFAs的产生以及氮和磷的释放;水解酸化初期,超声预处理比未经超声预处理的污泥在有机质、氮、磷释放率上差异非常明显,随着水解酸化的进行,有机质和氮释放率差异仍很明显,而磷释放程度逐渐接近;经0.6 W/mL超声预处理,污泥水解酸化3 d后,SCOD释放率、VFAs浓度、TN释放率和NH4+-N释放率分别是未经处理污泥的1.85、2.63、1.85和1.41倍,而TP和PO43--P释放率较未经处理污泥仅分别多2.44和1.23个百分点。研究表明,控制适宜的声能密度、超声时间和水解酸化进程是超声预处理强化剩余污泥水解酸化效果的关键。     

Will PM control undermine China's efforts to reduce soil acidification?

China’s strategies to control acidifying pollutants and particulate matter (PM) may be in conflict for soil acidification abatement. Acidifying pollutant emissions are estimated for 2005 and 2020 with anticipated control policies. PM emissions including base cations (BCs) are evaluated with two scenarios, a base case applying existing policy to 2020, and a control case including anticipated tightened measures. Depositions of sulfur (S), nitrogen (N) and BCs are simulated and their acidification risks are evaluated with critical load (CL). In 2005, the area exceeding CL covered 15.6% of mainland China, with total exceedance of 2.2 Mt S. These values decrease in the base scenario 2020, implying partial recovery from acidification. Under more realistic PM control, the respective estimates are 17.9% and 2.4 Mt S, indicating increased acidification risks due to abatement of acid-neutralizing BCs. China’s anthropogenic PM abatement will have potentially stronger chemical implications for acidification than developed countries.     

Effects of canopy-deposition interaction on H+ supply to soils in Pinus banksiana and Populus tremuloides ecosystems in the Athabasca oil sands region in Alberta, Canada

Soil acidification has been of concern in the oil sands region in Alberta due to increased acid deposition. Using the canopy budget model, and accounting for H⁺ canopy leaching by organic acids, we determined sources and sinks of H⁺ in throughfall in jack pine (Pinus banksiana) and trembling aspen (Populus tremuloides) stands in two watersheds from 2006 to 2009. In pine stands, H⁺ deposition was greater in throughfall than in bulk precipitation while the opposite was true in aspen stands. The annual H⁺ interception deposition was 148.8-193.8 and 49.7-70.0 mol_c ha⁻¹ in pine and aspen stands, respectively; while the annual H⁺ canopy leaching was 127.1-128.7 and 0.0-6.0 mol_c ha⁻¹, respectively. The greater H⁺ supply in pine stands was caused by greater interception deposition of SO₄²⁻ and organic acids released from the pine canopy. Such findings have significant implications for establishing critical loads for various ecosystems in the oil sands region.     

Use of Water Clarity to Monitor the Effects of Climate Change and other Stressors on Oligotrophic Lakes

We present evidence from studies oflakes in Killarney Park, Ontario, Canada that waterclarity is a key variable for monitoring theeffects of climate change, high UV exposure andacidification. In small oligotrophic lakes, thesestressors affect water clarity primarily byaltering the concentration of DOC in lake water. Clear lakes (<2 mg L^-1 DOC) proved to be highlysensitive indicators of stressors, exhibiting largethermal and optical responses to small changes inDOC. Extremely clear (<0.5 mg L^-1 DOC) acidic lakesshowed the effects of climate change and solarbleaching in recent decades. These lakes becamemuch clearer even though they were slowlyrecovering from acidification.