Major factors of industrial noise-induced hearing loss in Hong Kong

A tripartite participation of government, trade unions and university was formed in 1988 to study the situation of industrial noise and hearing acuity of workers. Since 1982, the six industries identified by the Noise Control Office were construction, electronics, metals, plastics, shipbuilding and repairing, and textiles. Safety-subcommittees were formed. With the help of these subcommittees, 21 out of 32 medium-size factories responded to the study. A total of 922 sound measurements were made and 1062 out of 10724 workers were examined. More than one third (37.5%) of workers worked in locations with noise level in excess of L _eq (8h) 90 dBA. Among examined subjects, 39.8% were exposed to L _eq (8) 90 dBA and above and 18.6% were found to have industrial hearing loss. Multiple logistic regression analyses adjusted for sex and age showed that for hearing loss, the important risk factors were duration of occupational noise exposure, noise intensity, floor vibration and military experience. Current legislation and measures in hearing conservation were inadequate despite the implementation of inspection by the Noise Control Office. Recommendations were directed at amending relevant legislation, increasing supervision of use of personal ear protection, and strengthening health education and audiometric surveillance of exposed workers.     

COD adsorption capacity of the activated sludge — Its determination and application in the activated sludge process

Proper control of the activated sludge process is essential in ensuring production of good effluent. COD adsorption capacity (CAC) of the activated sludge could be used as a control parameter. CAC is determined by mixing the activated sludge with the settled sewage and measuring the instantaneous COD reduction per unit mass of activated sludge. CAC measures substrate removal by physical adsorption and reflects the quality of the activated sludge. CAC of a healthy activated sludge increases with the flow along the aeration units. CAC could be used for process decision on variation in air supply and feed pattern to the aeration units. In a modified process to cope with sludge bulking problem, CAC could be used to estimate the air supply to the aeration unit which is merely used for reaerating the returned sludge.     

重金属铅,镉,锌对小麦DNA构象的影响

采用紫外吸收谱法，研究了不同浓度铅，镉，锌对小麦ＤＮＡ构象的影响。结果显示重金属铅，镉，锌均可影响小麦ＤＮＡ构象，使其紫外吸收峰值发生变化。其中，铅离子对小麦ＤＮＡ构象影响最大，５０μｇ／ｍｌ＾ｐｂ＾２＋处理使小麦出现明显减色反应，１０００μｇ／ｍｌｐｂ＾２＋处理使其沉淀析出；镉离子对小麦ＤＮＡ构象影响不大，可使其产生轻微减色反应，低浓度锌离子使小麦ＤＮＡ发生增色反应，而高浓度使小麦ＤＮＡ发生减色     

等温气相色谱法测定土壤中甲基汞

样品采用碱消化，室温下在pH＝4．9时进行乙基化反应，氢气为载气，Carbotrap富集有机态汞，等温气相色谱（GC）分离，用冷原子萤光仪（CVAFS）测定。方法检出限20pg。线性范围100～600pg。回收率在95％～105％之间。     

中国高等环境教育体系现状分析

通过中国高等环境教育体系现状的系统分析，就面向２１世纪的中国高等环境教育的改革和发展提出了完善专业环境教育的层次结构，尽快建成合理完善的环境类学科专业体系及其相应的课程体系，大力发展成人高等环境教育，在非环境专业全面普及环境教育等建议．     

中压加氢裂化装置危险和可操作性研究

针对中压加氢裂化生产过程存在很大的火灾、爆炸、毒害等危险性的特点，以加氢裂化反应器出口至冷高压分离器进口之间管线为分析节点，对工艺参数流量可能发生的各种偏差进行了危险和可操作性研究，找出了偏差发生的原因及可能导致的后果，提出了相应的控制措施，对提高装置的安全可靠性，预防和减少事故发生具有重要作用。     

天津市PM10中元素的浓度特征和富集特征研究

为了解天津市大气PM10中元素的浓度水平和污染元素的来源,在天津市布置了7个采样点,获得了风沙季、非采暖季和采暖季19个元素的监测数据。结果表明:Ni、Pb、Cu、Cr是PM10中的主要超标污染元素;K、Ca、Na、Mg、Al、Si、Fe、Ti等8种元素是PM10浓度的主要贡献率元素(92%);19个元素的富集系数风沙季明显低于非采暖季;Co、Cu、Zn、Br、Pb五个元素各季和各站的富集系数均大于10,人为源贡献大于自然源,是环境治理的重点元素。     

岩爆倾向性的改进有限云评价模型与工程应用

为解决深部开采顶板岩爆评价问题,以挑水河磷矿为例,提出由3个岩爆倾向性评价指标e0/ec、e1/ec、ec/et组成的综合性评价指标体系,采用消除云雾化的综合权重法,建立顶板多指标岩爆倾向性的改进有限云评价模型;通过FLAC3D模拟计算采场的应力值,获得e0/ec、e1/ec、ec/et的参数值;开展挑水河磷矿顶板岩爆...     

Scientometric analysis on the review research evolution of tailings dam failure disasters

Environmental Science and Pollution Research - As the most severe damage form of tailings ponds, dam failure causes a serious threat and damage to the surrounding lives and environment. Therefore,...     

Comparison of biochar- and activated carbon-supported zerovalent iron for the removal of Se(IV) and Se(VI): influence of pH,ionic strength,and natural organic matter

Biochar (BC) and activated carbon (AC) were both produced from corn straw. Biochar-supported zerovalent iron (BC-ZVI) and activated carbon-supported zerovalent iron (AC-ZVI) were synthesized and applied for Se(IV)/Se(VI) removal. The sorption capacity of BC-ZVI for Se(IV) and Se(VI) was reported at 62.52 and 35.39 mg g^?1, higher than that of AC-ZVI (56.02 and 33.24 mg g^?1), respectively, due to its higher iron content and more positive charges. The spectroscopic analyses showed that Se(IV)/Se(VI) were reduced to Se(0)/Se(-II) of less toxicity and solubility. The effects of various factors such as pH, ionic strength, co-existing cations and anions, and natural organic matter (NOM) were also investigated. Ionic strength showed no significant effect on Se(IV)/Se(VI) removal, but pH was critical. The presence of NO₃^? and SO₄^2? did not cause obvious inhibition to the removal, while PO₄^3? inhibited the sorption capacity of BC-ZVI and AC-ZVI for Se(IV)/Se(VI) significantly. Common cations (K⁺, Ca²⁺, and Mg²⁺) were found to slightly enhance the removal, while NOM significantly decreased the sorption capacity of BC-ZVI and AC-ZVI for Se(IV)/Se(VI). Besides, NOM showed stronger inhibition effect on AC-ZVI than that on BC-ZVI. These results indicated that BC-ZVI, compared with AC-ZVI, could be a promising sorbent to remove Se(IV)/Se(VI) due to its low cost and high efficiency.