Natural pollution caused by the extremely acidic crater lake Kawah Ijen, East Java, Indonesia

Background. Aims and Scope Lakes developing in volcano craters can become highly acidic through the influx of volcanic gases, yielding one of the chemically most extreme natural environments on earth. The Kawah Ijen crater lake in East Java (Indonesia) has a pH 〈 0.3. It is the source of the extremely acid and metal-polluted river Banyupahit (45 km). The lake has a significant impact on the river ecosystem as well as on a densely populated area downstream, where agricultural fields are irrigated with water with a pH between 2.5 and 3.5. The chemistry of the river water seemed to have changed over the past decade and the negative effect in the irrigation area increased. A multidisciplinary approach was used to investigate the altered situation and to get insight in the water chemistry and the hydrological processes influencing these alterations. Moreover, a first investigation of the effects of the low pH on ecosystem health and human health was performed. Methods Water samples were taken at different sites along the river and in the irrigation area. Sampling for macroinvertebrates was performed at the same sites. Samples of soil and crop were taken in the irrigation area. All samples were analysed for metals (using ICP-AES) and other elements, and concentrations were compared to local and international standards. Results and Discussion The river carries a very high load of SO4, NH4, PO4, Cl, F, Fe, Cu, Pb, Zn, Al and other potentially toxic elements. Precipitation and discharge data over the period of 1980 – 2000 clearly show that the precipitation on the Ijen plateau influences water chemistry of the downstream river. Metal concentrations in the river water exceed the concentrations mentioned in Indonesian and international quality guidelines, even in the downstream river and the irrigation area. Some metal concentrations are extremely high, especially iron (up to 1600 mg/l) and aluminium (up to 3000 mg/l). The food-webs in the acidic parts of the river are highly underdeveloped. No invertebrates were present in the extremely acid water and, at pH 2.3, only chironomids were found. This also holds true for the river water with pH 3.3 in the downstream area. Agricultural soils in the irrigation area have a pH of 3.9 compared to a pH of 7.0 for soils irrigated with neutral water. Decreased yields of cultivated crops are probably caused by the use of Al containing acid irrigation water. Increased levels of metals (especially Cd, Co, Ni and Mn) are found in different foodstuffs, but still remain within acceptable ranges. Considering local residents” diets, Cd levels may lead to an increased risk for the human health. Fluoride exposure is of highest concern, with levels in drinking water exceeding guideline values and a lot of local residents suffering from dental fluorosis. Conclusions, Recommendations and Outlook In short, our data indicate that the Ijen crater lake presents a serious threat to the environment as well as human health and agricultural production.     

陆地生态环境酸沉降敏感性研究

酸雨对生态环境的影响已成为全球性的重大环境问题，本文在总结了世界酸雨现状、酸雨的生态危害、酸雨对土壤系统的影响及生态系统酸沉降敏感性等方面研究现状的基础上，对各方面的研究进展、存在的问题及发展趋势进行了评述和展望，并提出了若干研究方向及进一步研究需要注意的问题。     

Temporal and spatial relationships in fine particle strong acidity, sulphate, PM1O, and PM2.5 across multiple canadian locations

The Canadian Acid Aerosol Measurement Program (CAAMP) was established in 1992 to gain a better understanding of the atmospheric behaviour of fine particle strong acidity (“acid aerosols”) and to facilitate an assessment of the potential health risks associated with acid aerosols and particles in general. During 1992. 1993 and 1994, annular denuder and filter measurements were taken at four sites in Ontario, two in Quebec, three in the Atlantic Provinces and one in the greater Vancouver area. Mean fine particle sulphate concentrations (SO₄²⁻) were highest in southern Ontario (annual average ranged from 40–70 nmol m⁻³), lowest at a site in the Vancouver area (average = 16 nmol m⁻³) and second lowest in rural Nova Scotia. However, mean fine particle strong acid concentrations (H⁺) were geographically different. The highest mean concentrations were at the east coast sites (annual average of up to 30 nmol m⁻³). Acidities were lower in areas where the fine particle acidity experienced greater neutralization from reaction with ammonia. This included the major urban centres (i.e. Toronto and Montréal) and areas with greater amounts of agricultural activity, as in rural southern Ontario. On average, ambient concentrations of fine and coarse particle mass were larger in the urban areas and also in areas where SO₄²⁻ levels were higher. All the particle components were episodic. However, compared to SO₄²⁻ and fine particles (PM_2.5 or PM_2.1, depending upon inlet design), episodes of H⁺ tended to be less frequent and of shorter duration, particularly in Ontario. Saint John, New Brunswick, had the highest mean annual H⁺ concentration, which was 30 nmol m⁻³. H⁺ episodes (24 h concentration > 100 nmol m⁻³) were also the most frequent at this location. The high levels in Saint John were partially due to local sulphur dioxide sources and heterogeneous chemistry occurring in fog, which, on average, led to a 50% enhancement in sulphate, relative to upwind conditions.There was a substantial amount of intersite correlation in the day to day variations in H⁺, SO₄²⁻ , PM_2.5 and PM₁₀ (fine + coarse particles) concentrations, which is due to the influence of synoptic-scale meteorology and the relatively long atmospheric lifetime of fine particles. Sulphate was the most regionally homogenous species. Pearson correlation coefficients comparing SO₄²⁻ between sites ranged from 0.6 to 0.9, depending on site separation and lag time. In many cases, particle episodes were observed to move across the entire eastern portion of Canada with about a two-day lag between the SO₄²⁻ levels in southern Ontario and in southern Nova Scotia.     

Concentration, size distribution, and dry deposition rate of particle-associated metals in the Los Angeles region

Daily averaged atmospheric concentrations and dry deposition fluxes of particulate metals were measured seasonally at six urban sites and one non-urban coastal site in the Los Angeles region using a conventional total suspended particulate matter (TSP) filter, surrogate surface deposition plates, and a Noll Rotary Impactor (NRI), which provides information about particle size distribution in four size ranges above 6 μm. With the exception of the non-urban site, particulate metal concentrations and deposition fluxes were remarkably uniform spatially and temporally. At all sites there were significant metal concentrations on particles greater than 10 μm, a commonly used upper limit for many air quality monitoring studies, and these large particles were estimated to be responsible for most of the deposited mass of metals. Annual averaged values of deposition rates measured with a surrogate surface were in good agreement with values estimated using theoretical deposition velocities in conjunction with measured size-segregated particle concentrations. Image analysis of particles deposited on NRI stage A, which collects all particles greater than 6 μm, indicated nighttime metal concentrations and deposition at the non-urban coastal site was higher than in the day time due to offshore advection of urban air associated with the diurnal land breeze. Measured enrichments of crustal elements and metals were correlated, indicating efficient mixing of natural and anthropogenic material from different sources, hypothesized to be the result of cyclical resuspension and deposition of dust by moving vehicles and wind.     

森林降水化学的变化特征和机理

研究并比较了湖南酸雨区韶山小集水区林内降水的化学特征，结果表明，与大气降水相比，穿冠水和地表穿透水中的富集的离子浓度除了NO3^-和Na^ 外均明显增加，到达地表的降水离子增加倍数最高达34．3倍；离子总量最高倍数为8．1倍，乔木树冠层的离子富集作用大于灌木层。韶山的大气降水、穿冠水和地表穿透水的年均pH分别为4．61、5．54和5．85。持续大量的降水对森林上空的污染物有较高的清除效果。     

Base cation deposition in europe-part I. Model description, results and uncertainties

Deposition of base cations (Na⁺, Mg²⁺, Ca²⁺, K⁺) in Europe was mapped for 1989 with a spatial resolution of 10 x 20 km using the so-called inferential modeling technique. Deposition fields resembled the geographic variability of sources, land-use and climate. Dry deposition constituted on average 45% of the total base cation deposition in Europe. Modeled deposition estimates compared reasonably well with deposition estimates derived from throughfall and bulk-precipitation measurements made at 174 sites scattered over Europe. Using error propagation, the random and systematic error in total deposition for an average grid cell of 10 x 20 km was estimated to equal 35–50% and 25–40%, respectively. Within individual grids a relatively large variability in deposition is expected.     

高浓度难降解有机废水的催化氧化技术及其进展

根据催化剂的激活因子不同 ,本文将催化氧化法分为湿式催化氧化法 (WCO)、光催化氧化法 (PCO)和电催化氧化法 (ECO)三种 ,并阐述了各自的反应机理及应用研究状况 ,提出了今后需要加强的研究方向     

中国大气酸沉降与土壤酸化问题

我国对大气酸沉降的研究起自７０年代末．以酸雨研究占主导地位。我国酸雨现象区域性、发展性强，在地理上以南方酸性土壤地区为主，在成分上以硫酸盐型酸雨为主；无论是酸度还是频率，酸雨都是极严重的生态环境问题。酸沉降已对农、林生态系统生产产生了严重的破坏效应，但其累积性的环境化学反馈却未引起人们的足够重视。我国酸雨地区以强酸性富铝土壤为主，对大气酸沉降有较大的敏感性。应用β指标还表明，酸沉降可使南方主要土壤因酸化而在３０—６０年内降低ｐＨ一个单位。近年来对酸沉降诱发的土壤酸化研究以模拟降水的土柱试验为主，从ｐＨ下降、盐基淋出、Ａｌ及重金属移动等方面来提示出酸沉降可能对土壤产生的化学影响。但作为过程化学研究，其案例监测研究的报道尚很少。对于南方严重的酸雨现象，应加强实地动态监测和过程分析，注重Ａｌ化学及其对环境的反馈，将酸沉降对生态系统的破坏提高到生态毒理机制上。     

酸雨对农业生产的影响及其对策

酸雨是严重的环境问题之一。我国南部地区已成为继欧洲、北美之后世界第三大酸雨区。酸雨对农业生态环境和农作物产量产生严重的影响,并带来巨大的经济损失。控制酸雨的危害．主要控制各种来源的ＳＯ２排放。文章根据农业可持续发展的战略思想,提出各种有效的防治对策。     

长江中下游湖泊富营养化过程的湖泊沉积记录

长江中下游湖群区，历来是人类最活跃的场所，但由于近年来社会经济的迅速发展，湖泊富营养化问题日趋严重，对湖泊湿地变化与湖泊营养盐状况关系的分析是制定湖泊环境整治和生态修复的重要科学依据。长江中游湖泊——龙感湖的湖中心钻孔沉积物中硅藻组合和总磷变化记录了近百年来龙感湖富营养化过程。沉积物中湿地花粉与人湖营养盐关系以及磁化率的分析表明，流域内人类活动对湖周滩地的改造，破坏了湿地植被，助长了人湖物质的增加，湖泊营养相对富集，而流域农业化肥的使用导致了水质的进一步恶化。