A Comparative study on hydrochemical profile of Alang- World’s largest shipbreaking yard and Gopnath

The preset study was undertaken at Alang which is known as a world’s largest ship breaking yard and Gopnath (Gulf of khambhat), Gujarat, India. The tidal, geographical, and climatic features make Alang an ideal ship breaking location with thousandths of ships getting scrapped each year. The aim of this research was to monitor temporal and spatial variation of hydrochemical characteristics. The water samples were collected bimonthly basis from two different locations at both the site. The surface water quality of marine water was assessed using 14 hydrochemical parameter e.g. physical variables (Temperature, EC), chemical variables (pH, DO, PA, TA, Chloride, Total Hardness, Ca Hardness, Mg Hardness, and nutrients variables (Sulphate, Phosphate, Nitrate). In present study the pH of seawater at Alang ranged from 8.7 to 9.2 whereas pH of seawater at Gopnath ranged from 8.7 to 9.1. Salinity of Alang fluctuated from 26.5 to 35 % and salinity of Gopnath ranged from 29.7% to 35%. Temperature was reached maximum in pre monsoon period by 33°C and minimum was noticed in post monsoon with 24°C. The electrical conductivity of Alang and Gopnath ranged from 34 ms/cm to 50 ms/cm and 41 ms/cm to 74 ms/cm respectively. The DO refers to the amount of oxygen dissolved in the sea water and it is particularly important in limnology (aquatic ecology). The study shows that the DO at Alang and Gopnath varied from 6.3 mg/L to 7.6 mg/L and 6.7 mg/L to 7.2 mg/L respectively. Seawater is more alkaline due to hardness of water. Calcium and magnesium both play an important role in provoking the toxic effects of various ions and neutralizing the excess acid produced. The calcium and magnesium hardness of Alang’s seawater ranged from 2187 mg/L to 4776 mg/L and 787 mg/L to 1312 mg/L respectively, Whereas calcium and magnesium hardness of Gopnath’s seawater ranged from 2798 mg/L to 6595 mg/L and 790 mg/L to 1102 mg/L respectively. Maximum phosphate concentration recorded at Alang and Gopnath was 0.6 mg/L to 0.9 mg/L respectively. Whereas maximum sulphate concentration recorded at Alang and Gopnath was 2.4 mg/L to 2.0 mg/L respectively and the maximum concentration of nitrate at Alang was 1.2 mg/L and at Gopnath it was 1.7 mg/L respectively. The physicochemical parameter of water including pH, DO, Sulphate and nitrate were higher in Alang whereas Salinity, Hardness and phosphate concentration were higher in Gopnath. Shipbreaking activity carried out at Alang releases number of organic, inorganic chemicals as well as heavy metal which affect the marine water quality and the marine water quality of Gopnath is affected by the religious activity. This baseline study on marine environment monitoring, aquatic pollution and environmental sustainability will be helpful to ecologists, environmentalists and biologists to conserving, protecting, and managing Gujarat's existing marine ecosystems.本研究的开展地点为印度古吉拉特邦的阿兰（Alang，全球最大的拆船场地(ship breaking yard)）与戈普纳特（Gopnath，位于坎贝湾）。潮汐、地理与气候特征使阿兰成为理想的拆船场地，每年有数千艘船舶在此拆解。本研究旨在监测水化学特征的时空变化。研究以双月为间隔，从两处采样点各选取两个不同点位采集水样。本次研究采用14项水化学参数对海水表层水质进行评估，其中包括物理参数（温度、电导率(EC, Electrical Conductivity)）、化学参数（pH、溶解氧(DO, Dissolved Oxygen)、酚酞碱度(PA, Phenolphthalein Alkalinity)、总碱度(TA, Total Alkalinity)、氯化物、总硬度、钙硬度、镁硬度）以及营养盐参数（硫酸盐(Sulphate)、磷酸盐(Phosphate)、硝酸盐(Nitrate)）。本研究中，阿兰海域海水pH值介于8.7至9.2之间，戈普纳特海域海水pH值则介于8.7至9.1之间。阿兰海域盐度波动范围为26.5‰至35‰，戈普纳特海域盐度范围为29.7‰至35‰。水温在季风前时期达到峰值33℃，在季风后时期降至最低24℃。阿兰与戈普纳特海域的电导率范围分别为34 ms/cm至50 ms/cm、41 ms/cm至74 ms/cm。溶解氧指溶解于海水中的氧气含量，在湖沼学（水生生态学）领域具有重要意义。研究显示，阿兰与戈普纳特海域的溶解氧含量分别介于6.3 mg/L至7.6 mg/L、6.7 mg/L至7.2 mg/L之间。海水因水硬度而呈偏碱性。钙与镁均在增强多种离子的毒性效应以及中和过量生成的酸性物质方面发挥重要作用。阿兰海域海水的钙硬度与镁硬度范围分别为2187 mg/L至4776 mg/L、787 mg/L至1312 mg/L；戈普纳特海域海水的钙硬度与镁硬度范围则分别为2798 mg/L至6595 mg/L、790 mg/L至1102 mg/L。阿兰与戈普纳特海域记录到的磷酸盐最大浓度分别为0.6 mg/L与0.9 mg/L。阿兰海域硫酸盐最大浓度为2.4 mg/L，戈普纳特海域为2.0 mg/L；阿兰海域硝酸盐最大浓度为1.2 mg/L，戈普纳特海域则为1.7 mg/L。阿兰海域的水质理化参数中，pH、溶解氧、硫酸盐与硝酸盐含量均高于戈普纳特海域；而戈普纳特海域的盐度、硬度与磷酸盐浓度则更高。阿兰海域的拆船活动会释放多种有机、无机化学物质以及重金属，对海水水质造成影响；而戈普纳特海域的海水水质则受宗教活动影响。本项针对海洋环境监测、水生污染与环境可持续性的基线研究，可为生态学家、环境学家与生物学家保护、修复及管理古吉拉特邦现存海洋生态系统提供参考依据。