Cause analysis and treatment of acid wastewater pollution in xiayuanqiaotou coal mine of Kaili City, Guizhou Province

In this paper, the acid wastewater pollution caused by the closed pit of xiayuanqiaotou Coal Mine is taken as an example. Through hydrogeological survey and field inspection, the geological and hydrogeological conditions of the study area are understood, and the cause and discharge of acid wastewater pollution in the mining area are analyzed. The results show that the goaf and coal gangue leaching water formed by the disorderly mining of small coal kilns in the Yudonghe Vally are the main sources of acidic wastewater pollution, and direct drainage from the mine mouth is the main drainage method of pollution in the Yudong Vally.Based on this, the technology of source control plus terminal treatment has been adopted, and applying regional water treatment and prevention technology to treatment is a new model of both specimens and treatments.which will play a significant role in the treatment of acid mine water in Guizhou and the south in the future.

Removal of Metals by Sulphide Precipitation Using Na2S and HS−-Solution

Precipitation of metals as metal sulphides is a practical way to recover metals from mine water. Sulphide precipitation is useful since many metals are very sparingly soluble as sulphides. Precipitation is also pH dependent. This article investigates the precipitation of metals individually as sulphides and assesses which metals are precipitated as metal hydroxides by adjustment of the pH. The precipitation of different metals as sulphides was studied to determine the conditions under which the HS− solution from the sulphate reduction reaction could be used for precipitation. H2S gas and ionic HS− produced during anaerobic treatment could be recycled from the process to precipitate metals in acidic mine drainage (AMD) prior to anaerobic treatment (Biological sulphate reduction), thereby recovering several metals. Precipitation of metals with HS− was fast and produced fine precipitates. The pH of acid mine water is about 2–4, and it can be adjusted to pH 5.5 before sulphide precipitation, while the precipitation, on the other hand, requires a sulphide solution with pH at 8 and the sulphide in HS− form. This prevents H2S formation and mitigates the risk posed from the evaporation of toxic hydrogen sulphur gas. This is a lower increase than is required for hydroxide precipitation, in which pH is typically raised to approximately nine. After precipitation, metal concentrations ranged from 1 to 30 μg/L.

EFISIENSI SISTEM LAHAN BASAH BUATAN ALIRAN PERMUKAAN DENGAN VARIASI DEBIT DALAM MENYISIHKAN MANGAN PADA AIR ASAM TAMBANG

Terbentuknya air asam tambang (AAT) merupakan salah satu dampak dari adanya aktifitas pertambangan. Air asam tambang memiliki ciri pH asam berkisar antara 3-5, warna air kuning kemerahan, dengan konsentrasi besi (Fe) dan mangan (Mn) yang tinggi. Penyisihan Mn menjadi tantangan tersendiri karena mangan hanya dapat disisihkan jika konsentrasi Fe AAT kurang dari 5 mg/L. Teknologi yang kini dikembangkan untuk menyisihkan Mn air asam tambang adalah sistem lahan basah buatan (LBB). Kinerja LBB dipengaruhi oleh debit AAT. Untuk mengetahui efesiensi penyisihan mangan (Mn) dan nilai pH pada LBB, maka pada penelitian ini digunakan Lahan Basah Buatan Aliran Permukaan (LBB-AP) berdimensi 150cm x 50 cm x 75 cm beraliran kontinyu dengan variasi debit. Pada penelitian ini akan divariasi debit AAT yaitu D0 7,1 mL/menit; D1 8,8 mL/meni; D2 10,5 mL/menit, dan D3 12,2 mL/menit. Hasil penelitian menunjukkan peningkatan pH terbaik pada D0 7,1 mL/menit periode ke 4 dengan nilai pH 4,3. Kemampuan penyisihan Mn terbaik pada LBB D0 7,1 mL/menit periode ke 1 sebesar 3,3 mg/L dengan efisiensi sebesar 62%. Kata Kunci : air asam tambang, lahan basah buatan aliran permukaan, mangan, variasi debit. The formation of acid mine drainage (AAT) is one of the impacts of mining activities. Acid mine water has a characteristic low water pH ranging from 3-5, the color of reddish-yellow water, and has high concentrations of iron (Fe) and manganese (Mn). Mn removal is a challenge because manganese can only be removed if the concentration of Fe AAT is less than 5 mg / L. One of the technologies that can be used to remove Mn from acid mine drainage is the constructed wetland system (CW). CW performance is influenced by AAT debits. To determine the efficiency of removal of manganese (Mn) and the pH value in CW, then in this study used Surface Flow Constructed Wetland (SFCW) with dimensions of 150cm x 50 cm x 75 cm with the continuous flow with variations in debit. In this study, AAT debit will be varied, namely D0 7.1 mL / min; D1 8.8 mL / min; D2 10.5 mL / min, and D3 12.2 mL / min. The results showed the best pH increase at CW D0 7.1 mL/min for the 4th period with a pH value of 4.3. The best Mn removal ability at CW D0 7.1 mL/min in the first period was 3.3 mg / L with an efficiency of 62%. Keywords: Acid mine drainage, Debit variation, Manganese, Surface flow Constructed Wetland.